Post by: jacqmans on 04/10/2007 04:37 pm
RELEASE: 11-07
DAWN ARRIVES IN FLORIDA -- A LITTLE AFTER DAWN
The Dawn spacecraft arrived at Astrotech Space Operations in
Titusville, Fla., at 9 a.m. EDT today. Dawn, NASA's mission into the
heart of the asteroid belt, is at the facility for final processing
and launch operations. Dawn's launch period opens June 30.
"Dawn only has two more trips to make," said Dawn project manager
Keyur Patel of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
"One will be in mid-June when it makes the 15-mile journey from the
processing facility to the launch pad. The second will be when Dawn
rises to begin its eight-year, 3.2-billion-mile odyssey into the
heart of the asteroid belt."
The Dawn spacecraft will employ ion propulsion to explore two of the
asteroid belt's most intriguing and dissimilar occupants: asteroid
Vesta and the dwarf planet Ceres.
Now that Dawn has arrived at Astrotech near NASA's Kennedy Space
Center, final prelaunch processing will begin. Technicians will
install the spacecraft's batteries, check out the control thrusters
and test the spacecraft's instruments. In late April, Dawn's large
solar arrays will be attached and then deployed for testing. In early
May, a compatibility test will be performed with the Deep Space
Network used for tracking and communications. Dawn will then be
loaded with fuel to be used for spacecraft control during the
mission. Finally, in mid-May, the spacecraft will undergo
spin-balance testing. Dawn will then be mated to the upper stage
booster and installed into a spacecraft transportation canister for
the trip to Cape Canaveral Air Force Station. This is currently
scheduled for June 19, when it will be mated to the Delta II rocket
at Pad 17-B.
The rocket that will launch Dawn is a Delta II 7925-H manufactured by
the United Launch Alliance; it is a heavier-lift model of the
standard Delta II that uses larger solid rocket boosters. The first
stage is scheduled to be erected on Pad 17-B in late May. Then the
nine strap-on solid rocket boosters will be raised and attached. The
second stage, which burns hypergolic propellants, will be hoisted
atop the first stage in the first week of June. The fairing which
surrounds the spacecraft will then be hoisted into the clean room of
the mobile service tower.
Next, engineers will perform several tests of the Delta II. In
mid-June, as a leak check, the first stage will be loaded with liquid
oxygen during a simulated countdown. The next day, a simulated flight
test will be performed, simulating the vehicle's post-liftoff flight
events without fuel aboard. The electrical and mechanical systems of
the entire Delta II will be exercised during this test. Once the Dawn
payload is atop the launch vehicle, a final major test will be
conducted: an integrated test of the Delta II and Dawn working
together. This will be a combined minus and plus count, simulating
all events as they will occur on launch day, but without propellants
aboard the vehicle.
The NASA Launch Services Program at Kennedy Space Center and the
United Launch Alliance are responsible for the launch of the Delta
II.
The Dawn mission to Vesta and Ceres is managed by the JPL, a division
of the California Institute of Technology in Pasadena, for NASA's
Science Mission Directorate in Washington, D.C. The University of
California Los Angeles is responsible for overall Dawn mission
science. Other scientific partners include Los Alamos National
Laboratory, New Mexico; German Aerospace Center, Berlin; Max Planck
Institute for Solar System Research, Katlenburg, Germany; and Italian
National Institute of Astrophysics, Palermo. Orbital Sciences
Corporation of Dulles, Va., designed and built the Dawn spacecraft.
Additional information about Dawn is online at:
http://dawn.jpl.nasa.gov
Post by: punkboi on 04/11/2007 04:46 pm
All Aboard Dawn... The microchip bearing the names of 360,000 people are now on the spacecraft:
![]("http://img.photobucket.com/albums/v480/punkboi/dawn_microchip.jpg")
Post by: eeergo on 04/11/2007 09:11 pm
Post by: punkboi on 04/12/2007 05:22 pm
Images of Dawn at the Astrotech facility in Florida:
![]("http://img.photobucket.com/albums/v480/punkboi/dawn1_astrotech.jpg")
![]("http://img.photobucket.com/albums/v480/punkboi/dawn2_astrotech.jpg")
Post by: jacqmans on 04/14/2007 09:37 am
Launch Pad: Cape Canaveral Air Force Station, Fla.
Launch Vehicle: Delta II 7925-H
Launch Date: NET June 30, 2007
Launch Time: 15:13:15 p.m. EDT
NASA's Dawn spacecraft arrived at Astrotech Space Operations in
Titusville, Fla., on Tuesday at 9 a.m. for final prelaunch and
processing activities. The spacecraft was cleaned and inspected after
removal of the access panels.
Dawn's mission will be the first time a spacecraft will orbit two
planetary bodies on a single voyage: asteroid Vesta and the dwarf
planet Ceres. The Dawn spacecraft is managed by NASA's Jet Propulsion
Laboratory in Pasadena, Calif.
NASA's Launch Services Program at Kennedy Space Center and the United
Launch Alliance are responsible for the launch of the Delta II.
Post by: Analyst on 04/15/2007 02:37 pm
Analyst
Post by: jacqmans on 04/27/2007 09:10 pm
Launch Pad: Cape Canaveral Air Force Station, Fla.
Launch Vehicle: Delta II 7925-H
Launch Date: Targeted for June 30, 2007
Launch Time: 15:13:15 p.m. EDT
The "command and data handling" portion of the Comprehensive
Performance Test was completed on April 19. Additional comprehensive
performance tests are in progress. Thermal control system, attitude
control sub-system and fault protection testing continues.
Dawn's mission will mark the first time a spacecraft will orbit two
planetary bodies on a single voyage: asteroid Vesta and the dwarf
planet Ceres. NASA's Dawn spacecraft is managed by NASA's Jet
Propulsion Laboratory in Pasadena, Calif.
NASA's Launch Services Program at Kennedy Space Center and the United
Launch Alliance are responsible for the launch of the Delta II.
Post by: Ankle-bone12 on 04/29/2007 05:59 am
Post by: Jim on 04/29/2007 01:06 pm
Quote
Ankle-bone12 - 29/4/2007 1:59 AM
Question: What exactly is the Dawn spacecraft supposed to be doing that makes it so spaecial other than visiting two celestial bodies? In other words, what type of instruments does it contain?
http://dawn.jpl.nasa.gov/
http://dawn.jpl.nasa.gov/technology/index.asp
Post by: jacqmans on 05/07/2007 02:42 pm
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Launch Pad: Cape Canaveral Air Force Station, Fla.
Launch Vehicle: Delta II 7925-H
Launch Date: NET June 30, 2007
Launch Time: 15:13:15 p.m. EDT
Comprehensive spacecraft system performance testing continues.
Instrument final alignment is under way.
A test of the spacecraft's primary communications antenna is scheduled
for May 21.
The spacecraft solar arrays will be attached and deployed May 21 - 24.
No spacecraft issues or concerns have arisen during testing to date.
Post by: simonbp on 05/08/2007 07:30 pm
Quote
Ankle-bone12 - 29/4/2007 12:59 AM
Question: What exactly is the Dawn spacecraft supposed to be doing that makes it so spaecial other than visiting two celestial bodies? In other words, what type of instruments does it contain?
Simply put: Dawn is the first mission specifically designed to go to the largest members of asteroid belt. Ceres and Vesta are both very large (Ceres is technically a dwarf planet now), and relatively unknown; oddly enough, we know far more about Triton, the distant captured KBO of Neptune, than Ceres, right in our own backyard.
The specific usefulness of looking at the small objects of the solar system is that they represent a much older stage in planetary evolution; like a geneticist studying bacteria. To that end, it carries a visual camera (build in Germany), a visual and infrared spectrometer for finding the surface composition (built in Italy), and a gamma and neutron spectrometer for probing the interior of Ceres and Vesta (built at Los Alamos). In addition, Dawn uses solar electric propulsion, providing yet another verification of this increasingly useful technology.
Simon ;)
Post by: shuttlefan on 05/08/2007 09:04 pm
Post by: Jim on 05/09/2007 12:05 am
Quote
shuttlefan - 8/5/2007 5:04 PM
Anyone know when they plan to start stacking the Delta?
In the next few weeks
Post by: jacqmans on 05/11/2007 08:43 pm
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Astrotech Space Operations Facility
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: NET June 30, 2007
Launch Time: 15:13:15 p.m. EDT
Mission system performance testing continues and is planned to finish
Friday.
A test of the spacecraft's primary communications antenna is scheduled
for May 21.
The spacecraft solar arrays will be attached and deployed May 21 - 24.
The spacecraft will be moved to Astrotech's Hazardous Processing
Facility for fueling on May 26.
Post by: eeergo on 05/17/2007 05:16 pm
>BTW, it just occured to me... has there ever been a Delta II mission with no solid boosters attached to the first stage? I mean, just the main engine?</p>
Post by: Jim on 05/17/2007 05:39 pm
Delta, A, B, C, F, H. They had Thors for first stages
Also some of the Thor Agenas had no solids
Post by: jacqmans on 05/18/2007 09:10 pm
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Astrotech Space Operations Facility
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: Target June 30, 2007
Launch Window: 5:13:15 p.m. EDT
Preparations are under way for moving the Dawn spacecraft to an
adjacent clean room high bay for solar array integration.
Next week, the two spacecraft solar arrays, each consisting of four
panels, will be attached to the Dawn spacecraft and undergo
deployment testing. A solar array lighting test also will be
performed before the arrays are stowed for flight. This activity is
scheduled for May 21-24.
The spacecraft will be moved to Astrotech's Hazardous Processing
Facility for fueling on May 26.
The Delta II first stage will be hoisted into the launcher at Pad 17-B
on May 23 and attachment of the nine solid rocket boosters will
begin.
Post by: eeergo on 05/19/2007 09:35 am
The chip with 360000 people's names (among who I'm included :) ) was positioned below the high gain antenna yesterday:
![]("http://www-pao.ksc.nasa.gov/kscpao/images//medium/07pd1239-m.jpg")
![]("http://www-pao.ksc.nasa.gov/kscpao/images//medium/07pd1240-m.jpg")
Post by: shuttlefan on 05/23/2007 01:31 pm
Post by: Antares on 05/23/2007 07:41 pm
Quote
shuttlefan - 23/5/2007 9:31 AMToo much wind. Will try again tomorrow.
The Delta II First stage should be on the pad today!
Post by: Antares on 05/24/2007 12:46 pm
Quote
Antares - 23/5/2007 3:41 PMNow NET Friday. Still too much wind.Quoteshuttlefan - 23/5/2007 9:31 AMToo much wind.
The Delta II First stage should be on the pad today!
Post by: eeergo on 05/24/2007 07:36 pm
Images from KSC Media Archive: http://mediaarchive.ksc.nasa.gov/search.cfm?cat=4
Post by: MKremer on 05/24/2007 09:40 pm
CGI pics still don't have the realism (and visceral impact) of *real* pictures.
(as an example: http://www.esa.int/esa-mmg/mmg.pl?b=b&type=I&mission=Rosetta&single=y&start=7&size=b )
Post by: Antares on 05/25/2007 02:06 pm
Quote
shuttlefan - 23/5/2007 9:31 AMAeolus strikes again. The next try will be Monday. We've had strong winds off the Atlantic for 2 weeks now.
The Delta II First stage should be on the pad today!
Post by: meiza on 05/25/2007 03:24 pm
Post by: Jim on 05/25/2007 03:32 pm
Post by: shuttlefan on 05/26/2007 01:38 am
Post by: jacqmans on 05/26/2007 03:14 am
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Astrotech Space Operations Facility
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: June 30, 2007
Launch Time: 4:50:13 - 5:10:13 p.m. EDT
Solar array installation and deployment tests are scheduled to be
completed Friday.
The spacecraft is scheduled to move to the hazardous processing
facility on May 28. Xenon for the Ion Propulsion System is scheduled
to be loaded aboard June 1-2. Hydrazine, used for spacecraft control
and maneuvering, will be loaded aboard June 6.
The Delta II first stage, originally set for hoisting into the
launcher on Wednesday, has been rescheduled for May 28 due to high
wind conditions at Pad 17-B. This will be followed next week by
attachment of the nine solid rocket boosters.
Post by: kevin-rf on 05/26/2007 05:13 am
Everytime I see this thread I start humming that song....
Delta II Dawn what's that payload you have on?
Could it be a faded rose from eons gone by?
And did I hear you say it was a launching you here today
To send you on a mission in the sky-eye
Post by: shuttlefan on 05/29/2007 12:40 am
Post by: Jim on 05/29/2007 01:55 am
Post by: shuttlefan on 05/29/2007 02:40 am
Post by: punkboi on 05/30/2007 06:26 pm
Photos of the first stage now at Pad 17-B posted up:
Post by: Chris Bergin on 06/01/2007 01:59 am
Article coming soon.
Post by: Chris Bergin on 06/01/2007 04:07 am
Post by: punkboi on 06/02/2007 03:50 am
Post by: William Graham on 06/02/2007 10:59 am
Quote
eeergo - 17/5/2007 6:16 PMNo. Not a Delta II. Some old Thor-Delta varients did. Delta II only ever flys with 3, 4, or 9 boosters.
BTW, it just occured to me... has there ever been a Delta II mission with no solid boosters attached to the first stage? I mean, just the main engine?
Post by: Antares on 06/02/2007 10:34 pm
Quote
GW_Simulations - 2/6/2007 6:59 AMThere's an excellent rocket genealogy here:Quoteeeergo - 17/5/2007 6:16 PMNo. Not a Delta II. Some old Thor-Delta varients did. Delta II only ever flys with 3, 4, or 9 boosters.
BTW, it just occured to me... has there ever been a Delta II mission with no solid boosters attached to the first stage? I mean, just the main engine?
http://www.aero.org/publications/crosslink/winter2003/backpage.html
Notice where the Scout line merges with the Thor-Delta line.
Post by: Ankle-bone12 on 06/04/2007 02:46 am
Post by: Chris Bergin on 06/05/2007 10:48 pm
GEM mating to resume tomorrow.
Post by: jacqmans on 06/11/2007 08:43 pm
NASA OFFERS MEDIA ACCESS TO DAWN SPACECRAFT JUNE 14
NASA's Dawn spacecraft, targeted to launch aboard a Delta II rocket
from Cape Canaveral on July 7, will be the focus of a media
opportunity at 1:30 p.m. Thursday, June 14, at Astrotech in
Titusville, Fla. The event is an opportunity to photograph Dawn and
interview project and launch program officials about the mission.
Dawn's goal is to characterize the conditions and processes of the
solar system's earliest epoch 4.5 billion years ago by investigating
in detail two of the largest asteroids, Ceres and Vesta. They reside
between Mars and Jupiter in the asteroid belt. Scientists theorize
these were budding planets never given the opportunity to grow.
However, Ceres and Vesta each followed a very different evolutionary
path during the first few million years of the solar system's
evolution. By investigating two very different asteroids during the
spacecraft's eight-year flight, the Dawn mission aims to unlock some
of the mysteries of planetary formation. Dawn will be the first
spacecraft to orbit an object in the asteroid belt and the first to
orbit two bodies after leaving Earth.
For the media event, procedures for optically sensitive spacecraft
must be followed by individuals entering the clean room where the
spacecraft is being prepared for launch. Full clean room attire
(bunny suits) must be worn and will be furnished. Please do not wear
perfume, cologne or makeup. Long pants and closed-toe shoes must be
worn -- no shorts, skirts or high heels.
Camera equipment including tripods and photo accessories must be
cleaned under supervision of contamination-control specialists before
entering the clean room. All equipment must be self-contained; no
portable lights can be allowed. Non-essential equipment such as
suede, leather or vinyl camera bags or other carrying cases must be
left outside the clean room. No pencils or felt-tipped pens are
permitted; only ball-point pens may be used. No food, tobacco,
chewing gum, lighters, matches or pocketknives will be allowed.
Wireless microphones are allowed, but flash photography cannot be
permitted due to the sensitivity of the spacecraft's solar arrays.
There is adequate metal halide lighting in the facility for
photography (white with slight green cast; suggested exposure for
ISO-ASA 400 is 1/30 sec. at f/5.6).
Primary spokespersons available to the media will be:
Chris Russell, Dawn Principal Investigator
University of California at Los Angeles
Michael Mook, Dawn Program Manager
Orbital Sciences Corporation, Dulles, Va.
Armando Piloto, NASA-KSC Mission Manager
Kennedy Space Center, Fla.
NASA's Jet Propulsion Laboratory is responsible for the project
management of Dawn. Orbital Sciences Corporation built the Dawn
spacecraft. Other partners include Los Alamos National Laboratory,
Max Planck Institute for Solar System Research, the German Aerospace
Center, the Italian Space Agency, and the Italian National Institute
of Astrophysics. The NASA Launch Services Program at Kennedy Space
Center and the United Launch Alliance are responsible for the launch
of the Delta II.
On Thursday, media may proceed directly to Astrotech located in the
Spaceport Florida Industrial Park, 1515 Chaffee Drive, Titusville.
Access at the gate will start at 1:15 p.m. The event will begin at
1:30 p.m. and last approximately two hours.
Dawn's journey to the asteroid belt is made possible by ion
propulsion. Initially tested and proven successful on NASA's Deep
Space 1 mission, this innovative technology is now applied in the
design of the Dawn spacecraft. Ion propulsion allows Dawn to
undertake a mission that would be unaffordable -- or perhaps
impossible -- with a more conventional propulsion system. Two large
solar arrays, stretching approximately 65 feet from tip to tip once
deployed, help to harness power from the distant sun to the ion
engines. The power then ionizes the onboard xenon fuel and
accelerates the ions, which in turns accelerates the spacecraft.
For further information, contact the NASA News Center at KSC at
321-867-2468.
Post by: ShuttleDiscovery on 06/12/2007 07:16 pm
Post by: Chris Bergin on 06/13/2007 02:35 pm
Post by: Chris Bergin on 06/13/2007 02:43 pm
Post by: MKremer on 06/13/2007 05:20 pm
Looking at the brighter side - maybe using up all its bad luck before launch will mean a more perfect mission. :laugh:
Post by: punkboi on 06/13/2007 05:35 pm
I'd say something...but it's not gonna take away from the fact that bad luck and incompetence is becoming the trademark of this mission. :angry:
Post by: MKremer on 06/13/2007 06:34 pm
Post by: jimvela on 06/13/2007 08:07 pm
http://space.newscientist.com/article/dn12060-dawn-spacecraft-damaged-but-still-set-for-launch.html
Post by: jacqmans on 06/13/2007 09:24 pm
DAWN MEDIA OPPORTUNITY RESCHEDULED TO JUNE 20
The media opportunity for Dawn scheduled for Thursday, June 14, at
Astrotech in Titusville has been rescheduled to Wednesday, June 20,
to allow spacecraft spin test activities to be completed. Media
access to Astrotech on Wednesday morning will begin at 10:15 a.m. and
the event will start at 10:30 a.m.
This will be an opportunity to photograph NASAâ?Ts Dawn spacecraft and
interview project and launch program officials about the mission.
Dawn is targeted to launch aboard a Delta II rocket from Cape
Canaveral on July 7.
Dawn's goal is to characterize the conditions and processes of the
solar system's earliest epoch 4.5 billion years ago by investigating
in detail two of the largest asteroids, Ceres and Vesta. They reside
between Mars and Jupiter in the asteroid belt. Scientists theorize
these were budding planets never given the opportunity to grow.
However, Ceres and Vesta each followed a very different evolutionary
path during the first few million years of the solar system's
evolution. By investigating two very different asteroids during the
spacecraft's eight-year flight, the Dawn mission aims to unlock some
of the mysteries of planetary formation. Dawn will be the first
spacecraft to orbit an object in the asteroid belt and the first to
orbit two bodies after leaving Earth.
For the media event, procedures for optically sensitive spacecraft
must be followed by individuals entering the clean room where the
spacecraft is being prepared for launch. Full clean room attire
(bunny suits) must be worn and will be furnished. Please do not wear
perfume, cologne or makeup. Long pants and closed-toe shoes must be
worn -- no shorts, skirts or high heels.
Camera equipment including tripods and photo accessories must be
cleaned under supervision of contamination-control specialists before
entering the clean room. All equipment must be self-contained; no
portable lights can be allowed. Non-essential equipment such as
suede, leather or vinyl camera bags or other carrying cases must be
left outside the clean room. No pencils or felt-tipped pens are
permitted; only ball-point pens may be used. No food, tobacco,
chewing gum, lighters, matches or pocketknives will be allowed.
Wireless microphones are allowed, but flash photography cannot be
permitted due to the sensitivity of the spacecraft's solar arrays.
There is adequate metal halide lighting in the facility for
photography (white with slight green cast; suggested exposure for
ISO-ASA 400 is 1/30 sec. at f/5.6).
Primary spokespersons available to the media will be:
Chris Russell, Dawn Principal Investigator
University of California at Los Angeles
Michael Mook, Dawn Program Manager
Orbital Sciences Corporation, Dulles, Va.
Armando Piloto, NASA-KSC Mission Manager
Kennedy Space Center, Fla.
NASA's Jet Propulsion Laboratory is responsible for the project
management of Dawn. Orbital Sciences Corporation built the Dawn
spacecraft. Other partners include Los Alamos National Laboratory,
Max Planck Institute for Solar System Research, the German Aerospace
Center, the Italian Space Agency, and the Italian National Institute
of Astrophysics. The NASA Launch Services Program at Kennedy Space
Center and the United Launch Alliance are responsible for the launch
of the Delta II.
On Wednesday, media may proceed directly to Astrotech located in the
Spaceport Florida Industrial Park, 1515 Chaffee Drive, Titusville.
Access at the gate will start at 10:15 a.m. The event will begin at
10:30 a.m. and last approximately two hours.
Dawn's journey to the asteroid belt is made possible by ion
propulsion. Initially tested and proven successful on NASA's Deep
Space 1 mission, this innovative technology is now applied in the
design of the Dawn spacecraft. Ion propulsion allows Dawn to
undertake a mission that would be unaffordable -- or perhaps
impossible -- with a more conventional propulsion system. Two large
solar arrays, stretching approximately 65 feet from tip to tip once
deployed, help to harness power from the distant sun to the ion
engines. The power then ionizes the onboard xenon fuel and
accelerates the ions, which in turns accelerates the spacecraft.
For further information, contact the NASA News Center at KSC at
321-867-2468.
Post by: punkboi on 06/13/2007 09:56 pm
Quote
pad rat - 13/6/2007 11:32 AM The tech did not fall on the array. He was using a wrench on the clampband that holds the spacecraft to its payload attach fitting and the wrench slipped, gashing the composite sheet on which the solar cells are attached. The array manufacturer has examined the damage and will make repairs with no impact to the schedule. The tech feels really bad about this and made an apology to the team.
*Breathes a sigh of relief*
The tech deserves a dock in his next paycheck for that mishap. :bleh:
Post by: dbhyslop on 06/14/2007 01:04 am
Quote
punkboi - 13/6/2007 5:56 PM
p>*Breathes a sigh of relief*
The tech deserves a dock in his next paycheck for that mishap. :bleh:
Will docking his pay make him feel sorrier? Everyone--from garbagemen to air traffic controllers to generals and presidents--make mistakes. This mistake could just as easily been done by the guy next to him and he already feels horrible about it. Luckily its not going to delay the mission at all. No reason to start a lynch mob.
Post by: collectSPACE on 06/14/2007 01:16 am
Quote
jimvela - 13/6/2007 3:07 PMSpaceDaily.com also spoke with someone at KSC. And NASA Watch spoke with NASA Associate Administrator Alan Stern.
Another article on this topic appeared here:
http://space.newscientist.com/article/dn12060-dawn-spacecraft-damaged-but-still-set-for-launch.html
Post by: Chris Bergin on 06/14/2007 02:00 am
As far as Spacedaily, and their headline "Dawn spacecraft never damaged" - well that's just silly.
Post by: punkboi on 06/14/2007 03:23 am
Quote
dbhyslop - 13/6/2007 6:04 PMQuotepunkboi - 13/6/2007 5:56 PM p>Will docking his pay make him feel sorrier? Everyone--from garbagemen to air traffic controllers to generals and presidents--make mistakes. This mistake could just as easily been done by the guy next to him and he already feels horrible about it. Luckily its not going to delay the mission at all. No reason to start a lynch mob.*Breathes a sigh of relief*
The tech deserves a dock in his next paycheck for that mishap. :bleh:
Hmm... I guess I should've used a wackier emoticon to indicate I wasn't being serious. How 'bout this one? :laugh:
It's a good thing Dawn's launch window lasts for a couple of months (till October)...as opposed to just two months (January to February of last year, and February of this year if it didn't launch in '06) like New Horizons.
Post by: PDJennings on 06/14/2007 02:29 pm
Quote
punkboi - 13/6/2007 2:56 PMQuotepad rat - 13/6/2007 11:32 AM The tech did not fall on the array. He was using a wrench on the clampband that holds the spacecraft to its payload attach fitting and the wrench slipped, gashing the composite sheet on which the solar cells are attached. The array manufacturer has examined the damage and will make repairs with no impact to the schedule. The tech feels really bad about this and made an apology to the team.*Breathes a sigh of relief*
The tech deserves a dock in his next paycheck for that mishap. :bleh:
It's always easy to blame the techs. Clampband bolts can take a lot of torque, even for the non-flight test stand variety. Normally, on commercial satellites, these bolts are clocked away from the solar arrays when possible -- to prevent exactly this sort of mishap.
Post by: Delta Manager on 06/14/2007 02:33 pm
There was certainly damage to Dawn, I managed to see a phone yesterday but I'm not able to post, sorry.
Post by: punkboi on 06/14/2007 05:32 pm
Quote
pad rat - 14/6/2007 6:16 AM While it's true the launch window does extend into the fall, Phoenix (MSL) will take precedence if Dawn does not launch before its operations conflict with the MSL launch. No, I don't know at what point Dawn would be put on a backburner (I may know later), but Phoenix does have precedence in the science pecking order. The reason Phoenix holds precedence is its launch window is very finite and would lead to a two-year delay if missed. Dawn has somewhat more flexibility in its celestial mechanics.
MSL is a different mission... The Mars Science Laboratory doesn't launch till 2009.
Quote
Delta Manager - 14/6/2007 7:33 AM He's already said he was joking. It was a dumb comment, but loosen up on the kids.
I think the 'dumb comment' part negated it...but thanks for backing me up anyway. ;)
Post by: Chris Bergin on 06/14/2007 08:18 pm
Post by: Firestarter on 06/15/2007 05:02 am
Quote
As far as Spacedaily, and their headline "Dawn spacecraft never damaged" - well that's just silly.It's more than silly, it's inaccurate, unless they think the above is how it should look!
Post by: jimvela on 06/15/2007 05:33 am
Quote
Chris Bergin - 14/6/2007 2:18 PM
Large set of images of the damage has been acquired and published in L2. Here's one for those of you who aren't L2 members:
Crap, I wouldn't have wanted to be the poor SOB whom had to report that to JPL...
I work with a number of really good flight techs. This kind of thing is just crushing to the good ones, whom seldom if ever make that kind of mistake.
I used to think that some of the peculiar ways that they handle themselves was odd or silly, but you can sure learn an awful lot from listening to why they do and don't do certain things. The more that I see and hear of these things happening, the wiser those OGBs turn out to be! :laugh:
You can also learn a lot from pictures and accounts of what went wrong. Lessons learned, and all that. Thanks for sharing a peek for us not on L2!
Post by: jacqmans on 06/15/2007 07:36 am
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Astrotech Space Operations Facility
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: July 7, 2007
Launch Time: 4:09:31 - 4:36:22 p.m. EDT
NASA is investigating a minor mishap affecting the Dawn spacecraft. On
June 11, during a procedure to prepare the spacecraft for
spin-balance testing, the back of a solar array panel was slightly
damaged by a technician's tool. No solar cells were broken. The
necessary minor repairs will be made this weekend. There is no impact
to the launch date of July 7.
Loading of xenon for the ion propulsion system was completed last
week. Hydrazine, used for spacecraft control and maneuvering, was
loaded aboard June 10. The spacecraft was then weighed and placed on
a spin table for a series of spin tests that are currently under way.
Dawn will be mated to its associated upper-stage booster on June 21
and transported to Pad 17-B for mating to the Delta II on June 26.
At Pad 17-B, the operations to attach the Delta II solid rocket
boosters to the first stage are complete. The second stage is planned
to be hoisted atop the first stage on Friday.
Post by: punkboi on 06/18/2007 08:42 pm
Damage on Dawn's solar panel repaired
Post by: jacqmans on 06/19/2007 07:08 pm
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Astrotech Space Operations Facility
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: July 7, 2007
Launch Time: 4:09:31 - 4:36:22 p.m. EDT
Over the weekend, Dutch Space personnel completed the solar array
repair on Dawn as planned and spacecraft processing continues on
schedule.
Dawn will be mated to its associated upper-stage booster on Thursday
and transported to Pad 17-B at Cape Canaveral Air Force Station for
mating to the Delta II on June 27.
At Pad 17-B, the Delta II second stage was hoisted atop the first
stage on June 15.
Post by: Chris Bergin on 06/20/2007 08:36 pm
NASA has scheduled a news briefing at 2 p.m. EDT, Tuesday, June 26, to preview the July 7 launch of the asteroid belt-bound Dawn mission. The briefing will be held in the NASA Headquarters auditorium, 300 E St., S.W., Washington. It will air live on NASA Television and be streamed on the agency's Internet homepage at http://www.nasa.gov/.
Dawn will launch aboard a Delta II rocket from Cape Canaveral, Fla. The mission will investigate the asteroid belt's largest objects, the asteroid Vesta and the dwarf planet Ceres.
Briefing participants are:
-- Jim Adams, deputy director, Planetary Science Division, NASA Headquarters, Washington
-- Keyur Patel, Dawn project manager, NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif.
-- Chris Russell, Dawn principal investigator, University of California, Los Angeles
-- Carol Raymond, Dawn deputy principal investigator, JPL
-- Marc Rayman, Dawn project systems engineer, JPL
Reporters at participating NASA centers will be able to ask questions. For more information about NASA TV, streaming video, downlink and schedule information, visit:
http://www.nasa.gov/ntv
For information about NASA and agency programs, visit:
http://www.nasa.gov/
CONTACT: Dwayne Brown, Headquarters, Washington, +1-202-358-1726; or DC Agle, Jet Propulsion Laboratory, Pasadena, Calif., +1-818-354-0474, both of NASA
PRNewswire-USNewswire -- June 20
First Call Analyst:
FCMN Contact:
Source: NASA
Post by: punkboi on 06/21/2007 05:56 am
Post by: punkboi on 06/21/2007 09:57 pm
Post by: Bruce H on 06/25/2007 09:11 pm
NASA Teleconference to Replace Televised Dawn Mission Briefing
NASA has scheduled a media teleconference at 2:30 p.m. EDT, Tuesday, June 26, in place of the previously planned media science briefing about the Dawn mission. Dawn will explore the two largest objects in the asteroid belt in an effort to answer questions about the formation of our solar system.
Mission managers will discuss several issues that need to be resolved before Dawn's July 7-11 launch window. The briefing participants are:
-- Todd May, deputy associate administrator for programs, Science Mission Directorate, NASA Headquarters, Washington
-- Jim Adams, deputy director, Planetary Science Division, Science Mission Directorate, NASA Headquarters, Washington
Post by: rdale on 06/25/2007 09:39 pm
Post by: DaveS on 06/26/2007 06:28 pm
Link to the live teleconference can be found here: http://www.nasa.gov/audience/formedia/features/news_audio.html
Post by: eeergo on 06/26/2007 07:16 pm
If it has, what were the bad news? :O
Post by: DaveS on 06/26/2007 07:23 pm
Quote
eeergo - 26/6/2007 9:16 PMIt was only 15 minutes long. It wasn't really bad news, other than that they were working a few issues with the LV and the Range. They are confident that they'll have these issues worked out before the launch window opens.
Has the conference already finished? I can't find the link, only the press release...
If it has, what were the bad news? :O
Post by: rdale on 06/26/2007 07:27 pm
Post by: punkboi on 06/26/2007 07:49 pm
http://www.unmannedspaceflight.com/index.php?showtopic=3274&pid=93513&st=195&#entry93513
The planetary window closes July 19 and reopens Sept 7 or so.
The launch period closes July 11 as dictated because of a couple of reasons; one is that they need time to clean up the pad before bringing Phoenix out. The other reason is that you cannot conduct a launch with a spacecraft on the other launch pad. If it launches July 12 they say they won't have enough time to get ready for Phoenix to meet August 3. In addition if it can't launch they need time to remove Dawn from its rocket.
If they decide to launch Dawn July 7, it has 45 days to launch from there onward; the second stage has a short lifespan once it is fueled. They cannot get a new second stage until October or so; so if they decide to launch and Dawn isn't off the ground by July 11 they may be in trouble.
They also stated that if they decided to delay at this time and not press ahead next week, it would cost $25 million or so.
Post by: DaveS on 06/26/2007 09:44 pm
Quote
rdale - 26/6/2007 9:27 PMHe most likely read too much into the press release about the telecon and thought that it might announce some really bad news.
What was BruceH referring to with the "bad news" comment?
Post by: Jim on 06/26/2007 09:49 pm
Post by: Rocket Guy on 06/26/2007 10:05 pm
Quote
Jim - 26/6/2007 5:49 PM
A new second stage is not needed, the existing one would just need refurb
I believe that it takes longer to refurb the stage than to get a new one, so Dawn would get a new one if they attempt but don't launch July 7-11. As Jim pointed out on USF, the current Dawn stage can be refurbed but it would probably go to another mission down the line.
Post by: John44 on 06/27/2007 03:17 pm
Briefing participant:
-- Todd May, Deputy Associate Administrator for Programs, NASA Headquarters
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2535&Itemid=1
Post by: punkboi on 06/27/2007 07:09 pm
Dawn now at Pad 17-B... (Webcam shots of the spacecraft inside the Mobile Servicing Structure below)
Post by: jacqmans on 06/28/2007 03:13 am
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Astrotech Space Operations Facility
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: July 7, 2007
Launch Time: 4:09:31 - 4:36:22 p.m. EDT
In preparation for the upcoming July 3 Flight Readiness Review, the
mission team is working to resolve several issues. These include
engineering checkouts and analysis on solid rocket motor attachment
points strength; cork insulation repair; battery replacement; and
additional technical checkouts of the launch vehicle. Managers also
are ensuring that all tracking elements will be in place to support
the July 7-11 launch window.
The Dawn spacecraft arrived at Pad 17-B this morning and was hoisted
atop the Delta II launch vehicle.
The Flight Program Verification, an integrated test to verify that the
launch vehicle and the spacecraft are working together, is scheduled
for June 29.
The fairing will be installed around the Dawn spacecraft atop the
rocket on July 1.
Post by: punkboi on 07/01/2007 01:41 am
Post by: dsmillman on 07/03/2007 12:04 pm
Post by: Jim on 07/03/2007 12:10 pm
Post by: eeergo on 07/03/2007 01:55 pm
Mmmm... hope this is only a mistake, but in KSC Media Gallery there are some new photos of Dawn's encapsulation in the payload fairing. In their footnote, it's stated that "Launch is scheduled for Aug. 3." Is that correct? It'd mean the July 7-11 window cannot be met.
Anyway, here's one of the photos :)
![]("http://www-pao.ksc.nasa.gov/kscpao/images//medium/07pd1718-m.jpg")
Post by: dsmillman on 07/03/2007 02:06 pm
Post by: Jim on 07/03/2007 05:30 pm
Overall probability of violating weather constraints: 60%
Primary concern(s): Anvil Cloud Rule, Debris Cloud Rule, Cumulus Cloud Rule
Overall probability of violating weather constraints for 24 hour delay: 60%
Primary concern(s): Anvil Cloud Rule, Debris Cloud Rule, Cumulus Cloud Rule
Post by: DaveS on 07/03/2007 09:07 pm
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: July 7, 2007
Launch Time: 4:09:31 - 4:36:22 p.m. EDT
The flight readiness review was completed on Tuesday. All technical
issues were cleared.
Mission managers will hold a teleconference on Wednesday to discuss
the availability of telemetry assets. If it is determined there are
sufficient aircraft and ship assets available, the team will proceed
with propellant loading on Thursday.
Post by: Chris Bergin on 07/05/2007 12:22 am
Post by: jacqmans on 07/05/2007 04:26 am
NASA ANNOUNCES MEDIA EVENTS FOR DAWN LAUNCH ABOARD DELTA II
CAPE CANAVERAL, Fla. -- Launch of NASA's Dawn spacecraft is scheduled
for Saturday, July 7, from Pad 17-B at Cape Canaveral Air Force
Station, Fla. The launch window is 4:09 to 4:36 p.m. EDT. NASA's
Launch Services Program at the Kennedy Space Center is responsible
for the launch of Dawn aboard a Delta II rocket. United Launch
Alliance is conducting the launch service for NASA. The spacecraft
has been built for NASA by Orbital Sciences Corporation. Should the
launch be postponed 24 hours for any reason, the launch window will
extend from 4:04 to 4:33 p.m. EDT. For a 48-hour postponement, the
launch window will be from 3:56 to 4:25 p.m.
Dawn's goal is to characterize the conditions and processes of the
solar system's earliest epoch 4.5 billion years ago by investigating
in detail two of the largest asteroids, Ceres and Vesta. They reside
between Mars and Jupiter in the asteroid belt. Scientists theorize
these were budding planets never given the opportunity to grow.
However, Ceres and Vesta each followed a very different evolutionary
path during the solar system's first few million years. By
investigating two very different asteroids during the spacecraft's
eight-year flight, the Dawn mission aims to unlock some of the
mysteries of planetary formation. Dawn will be the first spacecraft
to orbit an object in the asteroid belt and the first to orbit two
bodies after leaving Earth. Recent images taken by the Hubble Space
Telescope raise further intriguing questions about the evolution of
these asteroids.
Prelaunch Press Conference
A prelaunch press conference will be held at the NASA News Center at
Kennedy Space Center at 1 p.m. EDT on Friday, July 6. Participating
in the briefing will be:
Jim Green, Director, Planetary Science Division
NASA Headquarters, Washington
Omar Baez, NASA Launch Director/Launch Manager
Kennedy Space Center, Fla.
Kris Walsh, Director of Delta NASA and Commercial Programs
United Launch Alliance, Littleton, Colo.
Keyur Patel, Dawn Project Manager
Jet Propulsion Laboratory, Pasadena, Calif.
Marc Rayman, Dawn Project Systems Engineer
Jet Propulsion Laboratory, Pasadena, Calif.
Joel Tumbiolo, U.S. Air Force Delta II Launch Weather Officer
45th Weather Squadron, Cape Canaveral Air Force Station
Dawn Mission Science Briefing
A mission science briefing will immediately follow the prelaunch press
conference. Participating will be:
David Lindstrom, Dawn Program Scientist
NASA Headquarters
Chris Russell, Dawn Principal Investigator
University of California, Los Angeles
Carol Raymond, Dawn Deputy Principal Investigator
Jet Propulsion Laboratory
Lucy McFadden, Dawn Co-investigator
University of Maryland
Mark Sykes, Co-investigator
Planetary Science Institute, University of Arizona
No post-launch press conference will be held. A post-launch release
will be issued after details on the state of health of Dawn can be
confirmed. The release is expected to be issued about
three-and-one-half hours after launch.
Accreditation and Media Access Badges for KSC
Those who need press accreditation and access badges to the Kennedy
Space Center to cover the Dawn prelaunch press conference and mission
science briefing should complete the accreditation process via the
Web by going to https://media.ksc.nasa.gov.
All accreditation requests for the Dawn prelaunch press conference and
mission science briefing must be received by the close of business
Friday, July 6. Media may obtain NASA access badges at the Pass and
Identification Building, the badging station located on State Road
405 just east of U.S. 1. Contact the NASA News Center at 321-867-2468
for further information.
Remote Camera Placement at Complex 17
Friday, July 6: Photographers who wish to set up remote cameras at the
Delta launch complex will be escorted by a NASA representative to Pad
17-B. Departure by vehicle convoy will be at 9 a.m. from the Space
Florida parking lot located on Poseidon Avenue adjacent to Gate 1 of
Cape Canaveral Air Force Station.
Tower Rollback Photo Opportunity at Complex 17
Saturday, July 7: There will be an opportunity to observe rollback of
the mobile service tower from around the Dawn/Delta II launch vehicle
at Pad 17-B. Media should report at 7 a.m. to the Space Florida
parking lot located on Poseidon Avenue adjacent to Gate 1 of Cape
Canaveral Air Force Station. Press credentials and identification
from a bona fide news organization will be required. Transportation
by government bus will be provided to Launch Complex 17. Media are
requested to wear long pants and closed-toe shoes.
Launch Day Press Site Access to Cape Canaveral Air Force Station
Saturday, July 7: Media covering the Dawn launch will be able to
obtain press access badges beginning at 2:30 p.m. at the Space
Florida parking lot outside Gate 1 of Cape Canaveral Air Force
Station. Press credentials and identification from a bona fide news
organization will be required to obtain an access badge. A driver's
license alone will not be sufficient. However, additional
identification will not be required for those who present a
pre-issued NASA accreditation badge for Dawn or a valid permanent
NASA-KSC picture badge.
To reach the Space Florida parking lot, after passing the Pass and
Identification Building outside Gate 1 of Cape Canaveral Air Force
Station, turn right at the traffic light at the intersection of State
Road 401 and Poseidon Avenue. Make an immediate left turn at the
Navaho display.
Because this launch uses a Delta II heavy configuration with larger
solid rocket boosters, Press Site 1 is not available for this launch.
Instead, viewing for the press will be atop the Trident Bluff on
south Cape Canaveral Air Force Station. There is no infrastructure at
this location, so news media should plan on being fully
self-contained. It is possible that a wireless Internet capability
may be available.
Departure in a vehicle caravan from Space Florida to the Trident Bluff
press launch viewing site will be at 2:45 p.m. Access badges cannot
be issued after that time.
News Center Hours for Launch
The NASA News Center at KSC will open for Dawn news operations
starting Thursday, July 5, from 8 a.m. to 4:30 p.m. On launch day,
Saturday, July 7, the news center will be closed but will reopen one
hour after launch in preparation for word on Dawn's state of health
and to issue the post-launch press release at about L+3.5 hours.
Starting Thursday, July 5, status reports on the launch of Dawn and
updates to the Media Advisory will be recorded on the KSC news media
codaphone at 321-867-2525.
NASA Web Prelaunch and Launch Coverage
NASA's home on the Internet, http://www.nasa.gov, will provide
extensive prelaunch and launch day coverage of the Dawn mission.
Live countdown coverage from NASA's Launch Blog begins at 2 p.m. EDT
on Saturday, July 7. Coverage will feature real-time updates as
countdown milestones occur, as well as streaming video clips
highlighting launch preparations and liftoff.
To access other interactive features, go to NASA's Dawn main page at
http://www.nasa.gov/dawn. For more information about Dawn mission
online events, contact Jeanne Ryba at 321-867-7824.
Television Coverage
On Friday, July 6, television coverage of the Dawn prelaunch press
conference and mission science briefing at KSC will begin at 1 p.m.
EDT. Two-way question and answer capability will be available from
other NASA field centers. On Saturday, July 7, television coverage of
the launch will begin at 2 p.m. EDT and conclude after spacecraft
separation from the Delta II rocket, which occurs 28.5 minutes after
launch. The broadcast network HDNet will also carry the launch in
high-definition television format from 4 to 4:30 p.m. EDT. For more
information, visit http://www.hd.net or check local listings.
Audio of the prelaunch press conference and mission science briefing
will be carried on the NASA "V" circuits, which may be accessed by
dialing 321-867-1260 or 321-867-7135 beginning at 1 p.m. EDT Friday,
July 6. On launch day, July 7, "Mission Audio," countdown activities
without NASA launch commentary, will be carried on 321-867-7135
beginning at 1 p.m. EDT. Audio of the NASA launch commentary will
begin at 2 p.m. EDT and will be available on 321-867-1220, 1240,
1260. It will also be available on amateur radio frequency 146.940
MHz (VHF) or 442.6 MHz (UHF), heard within Brevard County.
For information on receiving NASA Television, go to:
http://www.nasa.gov/multimedia/nasatv/digital.html
-end-
Post by: Jim on 07/05/2007 01:35 pm
Post by: dsmillman on 07/05/2007 01:59 pm
Post by: jacqmans on 07/05/2007 04:17 pm
LAUNCH OF DAWN POSTPONED 24 HOURS TO SUNDAY, JULY 8
The launch of NASA's Dawn spacecraft aboard a United Launch Alliance
Delta II rocket has been postponed 24 hours.
A lightning advisory this morning precluded the start of the Delta II
second stage fueling as scheduled. If weather remains unacceptable
this afternoon, fueling will be performed on Friday. Also this
morning, the temperature within the fairing caused the required
temperature of the second stage to be too warm for fueling to begin.
The fairing temperature is being lowered by 10 degrees so that
oxidizer loading can begin this afternoon if weather is acceptable.
The countdown dress rehearsal scheduled for today has also been
postponed until Friday.
The launch window on Sunday, July 8, extends from 4:04 to 4:33 p.m.
EDT. The chance of not meeting the launch weather criteria on Sunday
is 60 percent. Required launch telemetry assets downrange will be in
place to support the launch.
The Dawn mission science briefing scheduled for Friday, July 6, will
be held as scheduled starting at 1 p.m. EDT. The prelaunch press
conference will be held on Saturday at 1 p.m. following the launch
readiness review.
Post by: Jim on 07/06/2007 12:08 pm
Post by: DaveS on 07/06/2007 12:30 pm
Quote
Jim - 6/7/2007 2:08 PMLet me guess why. Lightning close to the pad again, once again delaying the hyper loading into the second stage right?
Another 24 hr delay
Post by: Antares on 07/06/2007 12:53 pm
Post by: Jim on 07/06/2007 01:23 pm
Post by: dsmillman on 07/06/2007 02:48 pm
I assume that the launch briefing has slipped to 1 PM Sunday.
Post by: DaveS on 07/06/2007 03:22 pm
Quote
dsmillman - 6/7/2007 4:48 PMScience briefing is today but the standard L-1 day prelaunch briefing has slipped to Sunday as Sunday is the current L-1 day.
Is the science briefing still on for 1 PM today?
I assume that the launch briefing has slipped to 1 PM Sunday.
Post by: Chris Bergin on 07/06/2007 03:24 pm
"Due to difficulties with a downrange telemetry aircraft and the availability of a tracking ship"
Post by: Chris Bergin on 07/06/2007 03:28 pm
The launch of NASA's Dawn spacecraft aboard a United Launch Alliance
Delta II rocket has been postponed to no earlier than Monday, July 9.
Due to difficulties with a downrange telemetry aircraft and the
availability of a tracking ship, a launch attempt cannot be made
before that time. Also, the weather forecast for the loading of
propellants aboard the Delta II second stage indicated the possibility
of not being able to complete the operation today.
If the launch occurs on Monday, the launch window is 3:56 to 4:25 p.m.
EDT. The launch weather forecast calls for a 40-percent chance of not
meeting the launch weather criteria on Monday.
Based on a Monday launch, the prelaunch press conference will be held
at 1 p.m. on Sunday, July 8, at the NASA Kennedy Space Center press
site.
Post by: Analyst on 07/06/2007 05:42 pm
Analyst
Post by: John44 on 07/06/2007 06:47 pm
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2546&Itemid=1
July 9, Monday
1 p.m. - Coverage and Commentary of Dawn Mission Launch (launch window is 3:56 to 4:25 p.m.) -
Post by: Rocket Guy on 07/07/2007 08:47 pm
Post by: Delta Manager on 07/07/2007 09:10 pm
Post by: DaveS on 07/07/2007 09:19 pm
Quote
Ben - 7/7/2007 10:47 PMYou mean that they have cancelled the July 15-19 window? If you do, then that's a shame. Was looking forward to this launch. Oh well, got Phoenix in August.
They are done till September.
Post by: Rocket Guy on 07/07/2007 09:25 pm
Post by: anik on 07/07/2007 10:41 pm
"Launch has been put off until September, NASA decided today"
Post by: Chris Bergin on 07/07/2007 11:04 pm
Press release:
July 7, 2007
Dwayne Brown
Headquarters, Washington
202-358-1726
RELEASE: 07-150
NASA MISSION TO ASTEROID BELT RESCHEDULED FOR SEPTEMBER LAUNCH
WASHINGTON - The launch of NASA's Dawn spacecraft, a mission that will
explore the two largest objects in the asteroid belt in an effort to
answer questions about the formation of our solar system, has been
rescheduled to September.
The decision was made Saturday to move the launch to September after
careful review by NASA's Science Mission Directorate officials,
working with Dawn mission managers, the Dawn principal investigator,
and with the concurrence of the NASA Administrator.
Primary reasons for the move were a combination of highly limited
launch opportunities for Dawn in July and the potential impact to
launch preparations for the upcoming Phoenix Mars Lander mission, set
for early August. A September launch for Dawn maintains all of the
science mission goals a July launch would have provided.
NASA will hold a news briefing at 11:30 a.m. EDT on Monday, July 9, to
preview the launch of the Phoenix Mars Lander. Prior to the Phoenix
presentations, media will have the opportunity to learn in more
detail about the rescheduled Dawn launch. The briefing will originate
from the NASA Headquarters auditorium, 300 E St., S.W., Washington.
It will air live on NASA Television and be streamed online at:
http://www.nasa.gov/ntv
The Phoenix mission, scheduled for liftoff in early August from Cape
Canaveral Air Force Station, Fla., will examine whether the icy soil
on Mars could have been a habitable environment for microbial life.
For more information about the Phoenix mission, visit:
http://www.nasa.gov/phoenix
For more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: Rocket Guy on 07/07/2007 11:23 pm
Post by: kevin-rf on 07/08/2007 01:27 am
So what do they lose delaying until September. Will the stay at Vesta be shortened so it can still catch Ceres?
Something to ponder, the IRS sets the rate one gets paid back for driving a car. It is currently something like 45 or 49 cents a mile. Delta Dawn will go 3 billion before mission end. How much is NASA saving the tax payer by flying on a Delta II ;)
Post by: Rocket Guy on 07/08/2007 02:23 am
Post by: Avron on 07/08/2007 01:49 pm
Post by: Jim on 07/08/2007 01:56 pm
Post by: Davie OPF on 07/08/2007 04:18 pm
Post by: edkyle99 on 07/08/2007 08:09 pm
Quote
Davie OPF - 8/7/2007 11:18 AM
Shuttle working on schedule. Atlas and Deltas both having problems. Oh the irony.
I wouldn't put money on Shuttle launching on its scheduled date either.
It has been a less than stellar year for U.S. space flight so far. Only eight orbital U.S. launch attempts have occurred to date, and two of those failed. China has out-launched the U.S. so far, with seven successful launches in seven attempts.
- Ed Kyle
Post by: Orbiter Obvious on 07/09/2007 12:20 am
Quote
edkyle99 - 8/7/2007 3:09 PMQuoteDavie OPF - 8/7/2007 11:18 AM
Shuttle working on schedule. Atlas and Deltas both having problems. Oh the irony.
I wouldn't put money on Shuttle launching on its scheduled date either.
It has been a less than stellar year for U.S. space flight so far. Only eight orbital U.S. launch attempts have occurred to date, and two of those failed. China has out-launched the U.S. so far, with seven successful launches in seven attempts.
- Ed Kyle
But launching satellites is one thing. A manned Shuttle mission, assembly flight to the ISS wins hands down and there's another launching in less than a month. US wins as no one can touch what Shuttle does.
Post by: mike robel on 07/09/2007 12:35 am
Gemini 7 and 6 - Launched 3 days apart from the same pad.
Later Gemini's and their Atlas-Agena targets launching 1 orbit apart...
Post by: Jim on 07/09/2007 12:37 am
Quote
Orbiter Obvious - 8/7/2007 8:20 PM
But launching satellites is one thing. A manned Shuttle mission, assembly flight to the ISS wins hands down and there's another launching in less than a month. US wins as no one can touch what Shuttle does.
Not so, shuttle is just another launch vehicle. There is little difference in the rigor required
Post by: Rocket Guy on 07/09/2007 12:55 am
Quote
Gemini 7 and 6 - Launched 3 days apart from the same pad.
Actually 11 days apart, but Gemini/Agena is a good example (though not the same pad).
Post by: SpaceCat on 07/09/2007 02:09 pm
Post by: Jim on 07/09/2007 02:13 pm
Quote
SpaceCat - 9/7/2007 10:09 AM
Speaking of Range Rats (well, I was on another thread) this would be a great time to still have Ascension up and operating- but- sigh... those days are gone.
It is still part of the ER
Post by: mike robel on 07/09/2007 11:18 pm
Post by: Avron on 07/09/2007 11:35 pm
Quote
SpaceCat - 9/7/2007 10:09 AM
Speaking of Range Rats (well, I was on another thread) this would be a great time to still have Ascension up and operating- but- sigh... those days are gone.
In them old days, did every little issue/ IPR /waver etc get sent up to the program level?
Post by: William Graham on 07/10/2007 09:26 pm
Post by: Rocket Guy on 07/10/2007 10:19 pm
Post by: SpaceCat on 07/11/2007 02:36 am
Quote
Avron - 9/7/2007 7:35 PMQuoteSpaceCat - 9/7/2007 10:09 AM
Speaking of Range Rats (well, I was on another thread) this would be a great time to still have Ascension up and operating- but- sigh... those days are gone.
In them old days, did every little issue/ IPR /waver etc get sent up to the program level?
Really can't say- I was just a lowly "Rat" back then. :)
RE: Ascension- thanks for the correction, Jim. I was under the impression it was totally shut down in favor of TDRS. I see now, the Air Force still has a presence there. Looking at the Dawn ground track- guess they're either too far west to be of use, or don't have the required instrumentation.
Post by: simonbp on 07/11/2007 04:16 am
Quote
pad rat - 9/7/2007 6:31 AM
According to the Dawn folks, the mission will retain all its objectives and capabilities.
And that's the beauty of an ion-powered mission: much less launch window constrains...
Simon ;)
Post by: jacqmans on 07/13/2007 03:36 pm
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Pad 17-B
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Timeframe: September
Dawn remains atop the Delta II launch vehicle at Pad 17-B. The
spacecraft will be removed from the launch vehicle and returned to a
payload processing facility late next week.
Program managers are working to determine a specific launch date based
on the launch window for the mission's science objectives, the
availability of the Eastern Range, and the necessary tracking, data
and telemetry support.
Post by: rsnellenberger on 07/13/2007 08:39 pm
Quote
mike robel - 9/7/2007 6:18 PM Ben, thanks for the correction. 11 days is still an impressive turn around. And how about an aborted liftoff on 1 day, followed by another go one day later (or was it two) for GT-6?
Impressive, but somewhat eclipsed by SpaceX doing virtually the same thing within a couple of hours...
Post by: Analyst on 07/14/2007 06:37 am
Analyst
Post by: Jim on 07/14/2007 01:26 pm
Quote
rsnellenberger - 13/7/2007 4:39 PMQuotemike robel - 9/7/2007 6:18 PM Ben, thanks for the correction. 11 days is still an impressive turn around. And how about an aborted liftoff on 1 day, followed by another go one day later (or was it two) for GT-6?Impressive, but somewhat eclipsed by SpaceX doing virtually the same thing within a couple of hours...
There was no payload (e.g. no paying customer) much less a manned spacecraft
Post by: jacqmans on 07/20/2007 07:32 pm
Mission: Dawn
Location: Pad 17-B
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Timeframe: September
Dawn remains atop the Delta II launch vehicle at Pad 17-B. The
spacecraft will be removed from the launch vehicle on Saturday, July
21, and returned to the Astrotech payload processing facility near
NASA's Kennedy Space Center.
A firm date for launch is still being determined based on the launch
window for the science of the mission, the availability of the
Eastern Range and the necessary tracking, data and telemetry support.
The launch opportunity extends from Sept. 7 to Oct. 15.
Post by: jacqmans on 07/27/2007 07:35 pm
Mission: Dawn
Location: Astrotech payload processing facility
Launch Pad: 17-B
Launch Vehicle: Delta II 7925-H
Launch Timeframe: Sept. 7 - Oct. 15
A firm date for launch is still being determined based on the launch
window for the science of the mission, the availability of the
Eastern Range and the necessary tracking, data and telemetry support.
The launch of Dawn is currently expected to occur no later than Sept.
26; however, a launch date as early as Sept. 7 is being preserved in
planning schedules.
Dawn was removed from the launch vehicle on Sunday, July 22. The
spacecraft was returned to the Astrotech payload processing facility
near Kennedy Space Center at 7:30 a.m. that day. No processing
activities are currently scheduled.
Post by: punkboi on 08/04/2007 11:14 am
September 26 is being eyed as the actual date for Dawn's launch...according to the NASA launch director working on Phoenix today. I hope it's sooner than that! Oh well.
Post by: jacqmans on 09/07/2007 05:04 pm
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Astrotech payload processing facility
Launch Vehicle: Delta II 7925-H
Launch Pad: 17-B
Launch Date: Sept. 26, 2007
Launch Window: 7:25 - 7:54 a.m. EDT
Engineers loaded liquid oxygen aboard the first stage late last week
as a test for first stage components.
Dawn spacecraft operational readiness testing is complete.
Spacecraft thermal blanket closeout work is being finished today.
Technicians will be installing Dawn into the payload canister on Sept.
10 for transportation to Launch Complex 17. The spacecraft will be
mated to the Delta II rocket at Pad 17-B on Sept. 11.
The flight program verification, an integrated launch readiness test
with the Dawn spacecraft integrated with the Delta II, is scheduled
for Sept. 13.
Installation of the payload fairing around the spacecraft is scheduled
for Sept. 19.
Post by: moose on 09/08/2007 03:54 am
We re-assembled the canister today and will perform the can up of the spacecraft/third stage on Monday morning. Then return to Astroworld later that evening for the 5 hour drive to the pad. We must do this in the absence of the sun otherwise it would get too hot inside (no environmental control inside the can). The Dawn spacecraft dudes are especially concerned about the Xenon tank pressure sensitivity to temperature, so we better not be stuck on the road when the sun comes up. :o
Post by: MKremer on 09/08/2007 04:07 am
Do you know if they reloaded/recharged the xenon since, or has the inital load been safe since the first launch prep fill?
Post by: Jim on 09/08/2007 01:31 pm
Quote
MKremer - 7/9/2007 12:07 AM
Thanks, moose. :)
Do you know if they reloaded/recharged the xenon since, or has the inital load been safe since the first launch prep fill?
They didn't touch it
Post by: TJL on 09/08/2007 06:23 pm
Post by: DaveS on 09/08/2007 06:58 pm
Quote
TJL - 8/9/2007 8:23 PMYes. Only the payload+third stage was removed.
When the Dawn mission was postponed in early July to September, was the Delta LV left at Pad 17-B?
Post by: punkboi on 09/10/2007 10:21 pm
http://mediaarchive.ksc.nasa.gov/search.cfm?cat=173
Dawn back in its payload canister... Ready to be returned to Pad 17-B tonight...
Post by: jacqmans on 09/12/2007 03:08 am
Dawn One Step Away From Asteroid Belt Trip
The Dawn spacecraft completed the 25-kilometer (15-mile) journey from Astrotech Space Operations in Titusville, Fla., to Pad-17B of the Cape Canaveral Air Force Station at 5:10 a.m. EDT today. The launch period for Dawn, NASA's eight-year, more than 5-billion-kilometer (3.2-billion-mile) odyssey into the heart of the asteroid belt, opens Sept. 26.
"From here, the only way to go is up," said Dawn project manager Keyur Patel of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We are looking forward to putting some space between Dawn and Mother Earth and making some space history."
Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail the massive asteroid Vesta and the dwarf planet Ceres. They reside between Mars and Jupiter in the asteroid belt. Scientists theorize these were budding planets never given the opportunity to grow. However, Ceres and Vesta each followed a very different evolutionary path during the solar system's first few million years. By investigating two diverse asteroids during the spacecraft's eight-year flight, the Dawn mission aims to unlock some of the mysteries of planetary formation. Dawn will be the first spacecraft to orbit an object in the asteroid belt and the first to orbit two bodies after leaving Earth. Recent images taken by NASA's Hubble Space Telescope raise further intriguing questions about the evolution of these asteroids.
Now that the Dawn payload is atop the Delta II 7925-H, a heavier-lift model of the standard Delta II that uses larger solid rocket boosters, a final major test will be conducted. This integrated test of the Delta II and Dawn working together will simulate all events as they will occur on launch day, but without propellants aboard the vehicle.
The Sept. 26 launch window is 4:25 to 4:54 a.m. PDT (7:25 to 7:54 a.m. EDT). Should the launch be postponed 24 hours for any reason, the launch window will extend from 4:20 to 4:49 a.m. PDT (7:20 to 7:49 a.m. EDT). For a 48-hour postponement, the launch window will be from 4:14 to 4:43 a.m. PDT (7:14 to 7:43 a.m EDT). Dawn's launch period closes Oct. 15.
The Dawn mission to Vesta and Ceres is managed by JPL for the NASA Science Mission Directorate in Washington. The University of California Los Angeles is responsible for overall Dawn mission science. Other scientific partners include Los Alamos National Laboratory, New Mexico; German Aerospace Center, Berlin; Max Planck Institute for Solar System Research, Katlenburg, Germany; and Italian National Institute of Astrophysics, Palermo. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft. The NASA Launch Services Program at Kennedy Space Center and the United Launch Alliance are responsible for the launch of the Delta II.
Additional information about Dawn is online at:
http://dawn.jpl.nasa.gov
Post by: UK_Dude on 09/12/2007 10:47 am
Hi
A very non-techy question here but could I ask where the best place to view the launch would be for public viewing?
We are a group of 5 and we will be coming from Kissimmee, if anyone could recommend the best spots it would be most appreciated.
The details for the launch as I understand are:
Event: Delta 2 • Dawn
Date: 9/26/2007
Time: 07:25:00 AM EST
Details: The United Launch Alliance Delta 2 rocket will launch NASA's Dawn spacecraft that will use an ion propulsion system to visit and orbit the asteroids Vesta and Ceres. The rocket will fly in the 7925-Heavy vehicle configuration.
Location: SLC-17B, Cape Canaveral Air Force Station, Florida
Thanks
Andy
Post by: mdmcgrory on 09/12/2007 12:31 pm
Quote
pad rat - 14/6/2007 9:16 AMThe reason Phoenix holds precedence is its launch window is very finite and would lead to a two-year delay if missed. Dawn has somewhat more flexibility in its celestial mechanics.Why is that? I mean it seems to me it still has to make the Earth-Mars launch window for a chemical rocket, to get a Mars grvity assist. It's hard for me to believe waiting up to three months and missing the window won't impact the amount of propellant (chemical and ion propulsion) to catch up to Mars and thus alter the encounter times and science we get back. I mean it is still using Mars as a gravity assist.Is the reason just that the ion propulsion was always going to be on outbound anyway, and taking a tighter orbit around the sun to speed up won't use any extra xenon? I'm really curious because I can't believe Dawn has a lot of margin to spare since it's launching on a Delta II Heavy. And ion propulsion or not I figured if you miss the Mars launch window you play dominoes for 22 months until you get another chance.This late launch has to effect the mission, right?Thanks in advance for anyone who clears up my confusion!-Mike
Post by: Jim on 09/12/2007 12:53 pm
Quote
UK_Dude - 12/9/2007 6:47 AM
Delta 2 Dawn viewing spots for the next launch - 9/26/2007
Hi
A very non-techy question here but could I ask where the best place to view the launch would be for public viewing?
We are a group of 5 and we will be coming from Kissimmee, if anyone could recommend the best spots it would be most appreciated.
The details for the launch as I understand are:
Event: Delta 2 Dawn
Date: 9/26/2007
Time: 07:25:00 AM EST
Details: The United Launch Alliance Delta 2 rocket will launch NASA's Dawn spacecraft that will use an ion propulsion system to visit and orbit the asteroids Vesta and Ceres. The rocket will fly in the 7925-Heavy vehicle configuration.
Location: SLC-17B, Cape Canaveral Air Force Station, Florida
Thanks
Andy
Jetty Park in Port Canaveral
Post by: Jim on 09/12/2007 12:55 pm
Quote
mdmcgrory - 12/9/2007 8:31 AMQuotepad rat - 14/6/2007 9:16 AMThe reason Phoenix holds precedence is its launch window is very finite and would lead to a two-year delay if missed. Dawn has somewhat more flexibility in its celestial mechanics.Why is that? I mean it seems to me it still has to make the Earth-Mars launch window for a chemical rocket, to get a Mars grvity assist. It's hard for me to believe waiting up to three months and missing the window won't impact the amount of propellant (chemical and ion propulsion) to catch up to Mars and thus alter the encounter times and science we get back. I mean it is still using Mars as a gravity assist.Is the reason just that the ion propulsion was always going to be on outbound anyway, and taking a tighter orbit around the sun to speed up won't use any extra xenon? I'm really curious because I can't believe Dawn has a lot of margin to spare since it's launching on a Delta II Heavy. And ion propulsion or not I figured if you miss the Mars launch window you play dominoes for 22 months until you get another chance.This late launch has to effect the mission, right?Thanks in advance for anyone who clears up my confusion!-Mike
It was flexible WRT ion propulsion, it has some excess propellant
Post by: UK_Dude on 09/12/2007 12:59 pm
Post by: Rocket Guy on 09/12/2007 10:04 pm
Quote
Jetty Park in Port Canaveral
Yes, end of the pier in Jetty Park:
http://www.launchphotography.com/Delta_2_Launch_Viewing.html
Any questions please ask or PM/email me. Good luck.
Post by: Rocket Guy on 09/12/2007 10:05 pm
Post by: jacqmans on 09/14/2007 03:50 pm
EXPENDABLE LAUNCH VEHICLE STATUS REPORT
Mission: Dawn
Location: Launch Pad 17-B
Launch Vehicle: Delta II 7925-H
Launch Date: Sept. 26, 2007
Launch Window: 7:25 - 7:54 a.m. EDT
On Tuesday, the Dawn spacecraft arrived at Pad 17-B at 5:10 a.m. after
an overnight rollout from the Astrotech payload processing facility.
At 8:01 a.m., Dawn was officially declared secure atop the Delta II
rocket. Technicians successfully conducted spacecraft state-of-health
checks on Wednesday.
The launch team completed the flight program verification on Thursday
without issues. This integrated launch readiness electrical test
ensures the Dawn spacecraft and Delta II rocket are working together
in unison.
Installation of the payload fairing around the spacecraft is scheduled
for Sept. 19.
Post by: jacqmans on 09/14/2007 08:21 pm
DAWN LAUNCHING ON DELTA II SEPT. 26 TO EXPLORE PLANETARY MYSTERIES
CAPE CANAVERAL, Fla. -- Launch of NASA's Dawn spacecraft is scheduled
for Wednesday, Sept. 26, from Pad 17-B at Cape Canaveral Air Force
Station. The launch window is 7:25 to 7:54 a.m. EDT. NASA's Launch
Services Program at the Kennedy Space Center is responsible for the
launch of Dawn aboard a Delta II rocket. United Launch Alliance is
conducting the launch service for NASA. Should the launch be
postponed 24 hours for any reason, the launch window will extend from
7:20 to 7:49 a.m. EDT. For a 48-hour postponement, the launch window
will be from 7:14 to 7:43 a.m.
Dawn's goal is to characterize the conditions and processes of the
solar system's earliest epoch 4.5 billion years ago by investigating
in detail two of the largest asteroids, Ceres and Vesta. They reside
between Mars and Jupiter in the asteroid belt. Scientists theorize
these were budding planets never given the opportunity to grow.
However, Ceres and Vesta each followed a very different evolutionary
path during the solar system's first few million years. By
investigating two diverse asteroids during the spacecraft's
eight-year flight, the Dawn mission aims to unlock some of the
mysteries of planetary formation. Dawn will be the first spacecraft
to orbit an object in the asteroid belt and the first to orbit two
bodies after leaving Earth. Recent images taken by the Hubble Space
Telescope raise further intriguing questions about the evolution of
these asteroids.
Prelaunch Press Conference
A prelaunch press conference will be held at the NASA News Center at
Kennedy Space Center at 1 p.m. EDT on Monday, Sept. 24. Participating
in the briefing will be:
Jim Adams, Deputy Director, Planetary Science Division
NASA Headquarters, Washington
Omar Baez, NASA Launch Director/Launch Manager
Kennedy Space Center
Kris Walsh, Director of Delta NASA and Commercial Programs
United Launch Alliance, Littleton, Colo.
Keyur Patel, Dawn Project Manager
Jet Propulsion Laboratory, Pasadena, Calif.
Marc Rayman, Dawn Project Systems Engineer
Jet Propulsion Laboratory
Joel Tumbiolo, U.S. Air Force Delta II Launch Weather Officer
45th Weather Squadron, Cape Canaveral Air Force Station
The Dawn mission science briefing held at KSC on July 6 will be
replayed immediately following the prelaunch press conference.
Dawn Post-launch Press Conference
A post-launch press conference will be held at the NASA News Center at
noon EDT to provide details on the state of health of the Dawn
spacecraft. Participating in the briefing will be:
Jim Adams, Deputy Directory, Planetary Science Division
NASA Headquarters
Keyur Patel, Dawn Project Manager
Jet Propulsion Laboratory
Chris Russell, Dawn Principal Investigator
University of California, Los Angeles
A post-launch press release will also be issued once first contact
with the Dawn spacecraft has been made through the Deep Space
Network's Goldstone tracking station. Official spokespersons will be
available at the NASA News Center for interviews at that time.
Accreditation and Media Access Badges for KSC and CCAFS
The accreditation process for NASA's expendable launch vehicle
missions has changed. All news media, including those who are
permanently badged, must complete the accreditation process for the
activities associated with the Dawn launch. The press accreditation
process may be done via the Web by going to:
https://media.ksc.nasa.gov/.
Accreditation requests for the Dawn prelaunch, launch and post-launch
activities at Kennedy Space Center and Cape Canaveral Air Force
Station must be received by the close of business Friday, Sept. 21.
Media without permanent credentials may obtain NASA access badges at
the Pass and Identification (Pass & ID) building located on State
Road 405 just east of U.S. 1. To obtain an access badge, two forms of
government-issued identification are required, including at least one
with a picture.
Badge pick-up timeline:
- by 7:30 a.m. on Monday, Sept. 24, for remote camera setup
- by noon on Monday, Sept. 24, for those attending the prelaunch
activities
- by 4 p.m. on Tuesday, Sept. 25, for attending the launch and
post-launch activities
Remote Camera Placement at Complex 17
Tuesday, Sept. 25: Photographers who wish to set up remote cameras at
the Delta launch complex will be escorted by a NASA representative to
Pad 17-B. Departure by vehicle convoy will be at 9 a.m. from the
Space Florida parking lot located on Poseidon Avenue, adjacent to
Gate 1 of Cape Canaveral Air Force Station.
Launch Day Press Site Access to Cape Canaveral Air Force Station
Wednesday, Sept. 26: Verification of pre-issued press credentials and
sign-in will begin at 6 a.m. at the Space Florida parking lot. Media
covering the Dawn launch will be required to show their permanent KSC
credentials or temporary KSC machine badge before being allowed to
participate in the caravan traveling to the media viewing site.
Following the launch, media will be escorted via caravan back to Gate
1. Those media requiring access to the KSC Press Site for post-launch
activities must proceed through Gate 2 on State Road 3. Media
requiring remote camera retrieval will remain at the media viewing
site until escorted to the launch pad. Following camera retrieval,
participating media will be escorted back to Gate 1.
To reach the Space Florida parking lot, after passing the Pass and
Identification Building outside Gate 1 of Cape Canaveral Air Force
Station, turn right at the traffic light at the intersection of S.R.
401 and Poseidon Avenue. Make an immediate left turn at the Navaho
display.
Press Site 1 is currently planned to be used for this launch. However,
because this launch is a Delta II Heavy configuration with larger
solid rocket boosters, there is a chance that for safety reasons the
media viewing site will be atop the Trident Bluff on south Cape
Canaveral Air Force Station. There is no infrastructure at this
location, so news media should plan on being fully self-contained. A
wireless Internet capability will be available. Check with the NASA
News Center at KSC if it is necessary to determine in advance which
viewing site will be used.
News Center Hours for Launch
The NASA News Center at KSC will open for Dawn news operations
starting Monday, Sept. 24, from 8 a.m. to 4:30 p.m. Status reports on
the launch of Dawn and any updates to the media advisory will be
recorded on the KSC news media codaphone at 321-867-2525.
Television Coverage
On Monday, Sept. 24, television coverage of the Dawn prelaunch press
conference at KSC will begin at 1 p.m. EDT. Two-way question and
answer capability will be available from other NASA field centers. On
Wednesday, Sept. 26, television coverage of the launch will begin at
5:15 a.m. EDT and conclude after spacecraft separation from the Delta
II rocket which occurs 62 minutes after launch. The broadcast network
HDNet will also carry the launch in high-definition television format
from 7 to 7:30 a.m. EDT. For more information, visit
http://www.hd.net or check local listings.
Audio of the prelaunch press conference will be carried on the NASA
"V" circuits which may be accessed by dialing 321-867-1220, 1240,
1260 beginning at 1 p.m. EDT Monday, Sept. 24. On launch day, Sept.
26, "Mission Audio," countdown activities without NASA launch
commentary, will be carried on 321-867-7135 beginning at 4:15 a.m.
EDT. Audio of the NASA launch commentary will begin at 5:15 a.m. EDT
and will be available on 321-867-1220, 1240, 1260. It will also be
available on amateur radio frequency 146.940 MHz (VHF), heard within
Brevard County.
For information on receiving NASA Television, go to:
http://www.nasa.gov/multimedia/nasatv/digital.html
NASA Web Prelaunch and Launch Coverage
NASA's home on the Internet, http://www.nasa.gov, will provide
extensive prelaunch and launch day coverage of the Dawn mission.
Live countdown coverage from NASA's Launch Blog begins at 5:15 a.m.
EDT on Wednesday, Sept. 26. Coverage will feature real-time updates
as countdown milestones occur, as well as streaming video clips
highlighting launch preparations and liftoff.
To access other interactive features, go to the NASA Dawn main page at
http://www.nasa.gov/dawn. For more information about Dawn mission
online events, contact Jeanne Ryba at 321-867-7824.
Post by: infocat13 on 09/15/2007 01:19 am
Post by: punkboi on 09/15/2007 02:38 am
Post by: dsmillman on 09/15/2007 01:16 pm
http://planetary.org/blog/
Post by: Chris Bergin on 09/17/2007 12:36 am
Post by: punkboi on 09/18/2007 06:45 pm
The Delta II carrying the Worldview 1 satellite launched from Vandenberg AFB in California about 10 minutes ago. That officially paves the way (overlooking the flight and launch readiness reviews) for Dawn to launch next Wednesday. Hopefully. :)
EDIT: Thanks for that file, Chris
Post by: Chris Bergin on 09/21/2007 09:35 pm
http://affiliates.foxnewsradio.com/media/podcast/talk/AFMW/afmw_dr_christopher_russell.mp3
Post by: William Graham on 09/21/2007 09:58 pm
Post by: MKremer on 09/21/2007 10:07 pm
Quote
GW_Simulations - 21/9/2007 4:58 PM
Anyone got any news on weather around the time of launch?
It's Florida - too early to tell. ;)
Ask again late Monday or early Tuesday.
Post by: Chris Bergin on 09/23/2007 08:40 pm
Post by: TJL on 09/23/2007 09:22 pm
Quote
Chris Bergin - 23/9/2007 4:40 PM
Bad Weather today delayed 2nd stage fueling, causing 24 hour slip. Source.
Same thing happened with Delta / Phoenix last month.
Post by: DaveS on 09/23/2007 09:54 pm
Quote
TJL - 23/9/2007 11:22 PMAnd the first slips of the Dawn July launch dates.QuoteChris Bergin - 23/9/2007 4:40 PM
Bad Weather today delayed 2nd stage fueling, causing 24 hour slip. Source.
Same thing happened with Delta / Phoenix last month.
Post by: William Graham on 09/23/2007 10:37 pm
Post by: DaveS on 09/23/2007 10:47 pm
Quote
GW_Simulations - 24/9/2007 12:37 AMWith the current weather pattern at the Cape, yes.
Is this likley to happen again?
Post by: punkboi on 09/24/2007 12:09 am
Post by: dsmillman on 09/24/2007 12:48 pm
Post by: jacqmans on 09/24/2007 03:05 pm
NASA POSTPONES DAWN SPACECRAFT LAUNCH
CAPE CANAVERAL, Fla. -- The launch of NASA's Dawn spacecraft aboard a
United Launch Alliance Delta II rocket has been postponed 24 hours.
Fueling of the launch vehicle's second stage was unable to be
completed on Sunday because of weather conditions at the launch pad.
The launch now is scheduled for Thursday, Sept. 27, at the opening of
a window that extends from 7:20 a.m. to 7:49 a.m. EDT. For reporters
planning to establish remote cameras at the launch pad, set up has
been rescheduled and will take place at 9 a.m. on Wednesday, Sept.
26.
The prelaunch news conference is scheduled for 1 p.m., Tuesday, Sept.
25. Live launch coverage on NASA Television is set to begin Thursday
at 5:15 a.m.
For NASA TV streaming video, scheduling and downlink information,
visit:
http://www.nasa.gov/ntv
For more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: rdale on 09/24/2007 03:07 pm
Quote
dsmillman - 24/9/2007 8:48 AM
Does anyone know if the Dawn briefing scheduled for 1 PM EDT this afternoon will proceed?
That's just a straight replay of the July one - nothing new (and available already at Space-Multimedia).
Post by: DaveS on 09/24/2007 03:14 pm
Quote
rdale - 24/9/2007 5:07 PMNope. It's only the science briefing that is from July. Don't confuse the pre-launch briefing with the science briefing.Quotedsmillman - 24/9/2007 8:48 AM
Does anyone know if the Dawn briefing scheduled for 1 PM EDT this afternoon will proceed?
That's just a straight replay of the July one - nothing new (and available already at Space-Multimedia).
For ELV missions, they always hold two briefings, a pre-launch briefing that will give updates on how processing is going/gone and a science briefing about what kind of science they hope to gain from flying the mission.
Since the science hasn't changed since July, they will just replay the July briefing. But processing of the LV and spacecraft has changed since July, so that one will be new.
Post by: punkboi on 09/24/2007 04:53 pm
Second stage fueling complete with a 30% chance of unfavorable weather conditions Thursday morning
Post by: DaveS on 09/25/2007 04:59 pm
Post by: John44 on 09/25/2007 05:20 pm
#### Recorded in July ####
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2854&Itemid=1
Post by: John44 on 09/25/2007 08:49 pm
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2855&Itemid=2
Post by: jacqmans on 09/25/2007 08:49 pm
NASA SPACECRAFT IS A 'GO' FOR ASTEROID BELT
CAPE CANAVERAL, Fla. -- Launch and flight teams are in final
preparations for the planned Sept. 27 liftoff from Pad 17-B at Cape
Canaveral Air Force Station, Fla., of NASA's Dawn mission. The Dawn
spacecraft will venture into the heart of the asteroid belt, where it
will document in exceptional detail the mammoth rocky asteroid Vesta,
then the even bigger, icy dwarf planet Ceres.
"If you live in the Bahamas, this is one time you can tell your
neighbor, with a straight face, that Dawn will rise in the west,"
said Dawn Project Manager Keyur Patel of NASA's Jet Propulsion
Laboratory in Pasadena, Calif. "Weather permitting, we are go for
launch Thursday morning, a little after dawn."
Dawn's Sept. 27 launch window is 7:20 to 7:49 a.m. EDT. At the moment
of liftoff, the Delta II's first-stage main engine along with six of
its nine solid-fuel boosters will ignite. The remaining three solids
are ignited in flight following the burnout of the first six. The
first-stage main engine will burn for 4.4 minutes. The second stage
will deposit Dawn in a 185-kilometer-high (100-nautical-mile)
circular parking orbit in just under nine minutes. At about 56
minutes after launch, the rocket's third and final stage will ignite
for approximately 87 seconds. When the third stage burns out,
actuators and push-off springs on the launch vehicle will separate
the spacecraft from the third stage.
"After separation, the spacecraft will go through an automatic
activating sequence, including stabilizing the spacecraft, activating
flight systems and deploying Dawn's two massive solar arrays," said
Patel. "Then and only then will the spacecraft energize its
transmitter and contact Earth. We expect acquisition of signal to
occur anywhere from one-and-a-half hours to three-and-a-half hours
after launch."
The Dawn mission will explore Vesta and Ceres because these two
asteroid belt behemoths have been witness to so much of our solar
system's history.
"Visiting both Vesta and Ceres enables a study in extraterrestrial
contrasts," said Dawn Principal Investigator Christopher Russell of
the University of California, Los Angeles. "One is rocky and is
representative of the building blocks that constructed the planets of
the inner solar system. The other may very well be icy and represents
the outer planets. Yet, these two very diverse bodies reside in
essentially the same neighborhood. It is one of the mysteries Dawn
hopes to solve."
Using the same spacecraft to reconnoiter two different celestial
targets makes more than fiscal sense. It makes scientific sense. By
utilizing the same set of instruments at two separate destinations,
scientists can more accurately formulate comparisons and contrasts.
Dawn's science instrument suite will measure mass, shape, surface
topography and tectonic history, elemental and mineral composition,
as well as seek out water-bearing minerals. In addition, the Dawn
spacecraft itself and the way it orbits both Vesta and Ceres will be
used to measure the gravity fields of the celestial bodies.
"Understanding conditions that lead to the formation of planets is a
goal of NASA's mission of exploration," said David Lindstrom, Dawn
program scientist at NASA Headquarters in Washington. "The science
returned from Vesta and Ceres could unlock many of the mysteries of
the formation of the rocky planets including Earth."
Before all this celestial mystery unlocking can occur, Dawn has to
reach the asteroid belt and its first target, Vesta. This is a
four-year process that begins with launch and continues with the
firing of three of the most efficient engines in NASA's space motor
inventory: ion propulsion engines. Employing a complex commingling of
solar-derived electric power and xenon gas, these frugal powerhouses
must fire for months at a time to propel as well as steer Dawn. Over
their eight-year, almost 4-billion-mile lifetime, these three ion
propulsion engines will fire cumulatively for about 50,000 hours
(over five years) - a record for spacecraft.
The Dawn mission is managed by JPL for NASA's Science Mission
Directorate in Washington, D.C. JPL is a division of the California
Institute of Technology in Pasadena. The University of California,
Los Angeles, is responsible for overall Dawn mission science. Other
scientific partners include the Los Alamos National Laboratory, New
Mexico; Max Planck Institute for Solar System Research, Katlenburg,
Germany; and Italian National Institute of Astrophysics, Rome.
Orbital Sciences Corporation of Dulles, Va., designed and built the
Dawn spacecraft.
For more information about Dawn, visit:
http://www.nasa.gov/dawn
For more information about NASA and agency programs on the Internet,
visit:
http://www.nasa.gov
Note to Editors: A video file with animation, b-roll and sound bites
is airing on NASA TV today.
Post by: HIPAR on 09/25/2007 11:35 pm
Does anyone know how these work? What are those white patches inside the fairing?
--- CHAS
Post by: Nick L. on 09/25/2007 11:46 pm
I am not sure about the way the PLF is secured together, but the separation system uses linear explosives and explosive bolts, piston-cylinder pushers, and springs to push apart the fairing halves.
Post by: Jim on 09/26/2007 12:04 am
I should know what the patches are. They are not blanket vents since those are facing the fairing. I think it is conductive tape for charge dissipation.
Post by: moose on 09/26/2007 03:21 am
And every fairing uses acoustical blankets. They are not there because of thermal reasons.
Hope this helps.
Post by: charlieb on 09/26/2007 03:54 pm
Post by: Jim on 09/26/2007 04:14 pm
Quote
charlieb - 26/9/2007 11:54 AM
'moose' is correct; the white 'patches' are acoustic 'absorbers' designed to slightly attenuate the sound waves generated during launching. .
The white patches are on the black acoustic blankets and are not absorbers
Post by: rdale on 09/26/2007 04:21 pm
Post by: Chris Bergin on 09/26/2007 07:04 pm
Since weather will play a factor tomorrow, here are the launch windows this week.
Currently scheduled launch is Thurs 7:20am. They have until 7:49am to launch.
If there is a delay, most likely from weather, that moves launch to
Friday 7:14am - 7:43am
Saturday 7:09am - 7:38am
Post by: Chris Bergin on 09/26/2007 09:09 pm
Post by: punkboi on 09/26/2007 09:36 pm
Like what I did with Phoenix's launch, hopefully I wake up in the middle of the night tomorrow to watch online Dawn ready to rocket away from the Space Coast.
But then I probably just jinxed it right now. :bleh:
Post by: Ikelos on 09/26/2007 10:04 pm
Post by: DaveS on 09/26/2007 10:18 pm
Post by: rsnellenberger on 09/26/2007 10:19 pm
Quote
Chris Bergin - 26/9/2007 2:04 PM NASA Dawn mission Since weather will play a factor tomorrow, here are the launch windows this week. Currently scheduled launch is Thurs 7:20am. They have until 7:49am to launch. If there is a delay, most likely from weather, that moves launch to Friday 7:14am - 7:43am Saturday 7:09am - 7:38am
Chris, are those times Eastern Daylight Time (EDT), Central Daylight Time (CDT), British Summer Time (BST), or something else?
Post by: jabe on 09/26/2007 10:22 pm
Quote
rsnellenberger - 26/9/2007 6:19 PMEDT..check here (http://www.spaceflightnow.com/delta/d327/status.html) for other background info
Chris, are those times Eastern Daylight Time (EDT), Central Daylight Time (CDT), British Summer Time (BST), or something else?
Post by: Jim on 09/26/2007 10:33 pm
watch here
http://countdown.ksc.nasa.gov/elv/
Post by: HIPAR on 09/26/2007 11:38 pm
I cannot recognize the universe that I studied but I don't understand the universe as we see it now.
--- CHAS
Post by: joncz on 09/26/2007 11:57 pm
Is there a faded rose painted on the side?
----------
Most of you are too young to understand.
Post by: James Lowe1 on 09/27/2007 12:43 am
Post by: ChrisC on 09/27/2007 03:19 am
Quote
Jim - 26/9/2007 6:33 PMWow, that's a great little page, I'm glad I have Java working on my machine :)
watch here
http://countdown.ksc.nasa.gov/elv/
Are there any other hidden pages like that within http://countdown.ksc.nasa.gov ? That ELV page isn't linked from that Countdown home page, so I'm wondering if there are others lurking in there.
Post by: punkboi on 09/27/2007 03:21 am
Mobile Service Tower has rolled back... Delta II/Dawn is now directly underneath the night sky.
That was my poor attempt at waxing poetic. And stating the obvious.
Post by: Lee Jay on 09/27/2007 03:30 am
Quote
joncz - 26/9/2007 5:57 PM
The most important question is:
Is there a faded rose painted on the side?
----------
Most of you are too young to understand.
I don't see one in the pictures, but perhaps there was one in days gone by.
Post by: rdale on 09/27/2007 05:24 am
Post by: Jim on 09/27/2007 06:26 am
Quote
ChrisC - 26/9/2007 11:19 PMQuoteJim - 26/9/2007 6:33 PMWow, that's a great little page, I'm glad I have Java working on my machine :)
watch here
http://countdown.ksc.nasa.gov/elv/
Are there any other hidden pages like that within http://countdown.ksc.nasa.gov ? That ELV page isn't linked from that Countdown home page, so I'm wondering if there are others lurking in there.
the ELV page isn't associated with the shuttle page except for the URL. There aren't any more hidden
Post by: Chris Bergin on 09/27/2007 07:33 am
L-225 minutes.
As always, we really would love help with screenshots. With this being an early morning US launch, please feel free to help out, even if you're not a regular.
Post by: SimonShuttle on 09/27/2007 09:02 am
Post by: RHAnthony on 09/27/2007 09:10 am
Busy here at JPL for all of us! DSN is completely GREEN to support DAWN's launch, and from what I can gather on all of the voice loops that are bursting at the seams, everything else is too! Promises to be a great morning show. I'll try to update the thread from my point of view as things unfold now that I'm online to support it... but since I'm actually *working* on it, forgive me for any gaps in 'coverage'!
3 Antennas at the DSN Goldstone complex are set to catch it's signal, with DSS-15 having initial acquisition.
Edit: early morning typo's
Post by: Chris Bergin on 09/27/2007 09:11 am
Post by: Chris Bergin on 09/27/2007 09:12 am
Post by: RHAnthony on 09/27/2007 09:12 am
Edit: Chris, I didn't post this, but it says it was me. ?!?
Post by: RHAnthony on 09/27/2007 09:15 am
Post by: Chris Bergin on 09/27/2007 09:16 am
Post by: RHAnthony on 09/27/2007 09:18 am
Post by: Chris Bergin on 09/27/2007 09:19 am
Loading of RP1 is complete (as noted). PAO guy sounds half asleep!
Post by: RHAnthony on 09/27/2007 09:23 am
Post by: RHAnthony on 09/27/2007 09:23 am
Post by: Chris Bergin on 09/27/2007 09:24 am
Post by: Chris Bergin on 09/27/2007 09:26 am
Post by: Terry Rocket on 09/27/2007 09:27 am
Post by: Chris Bergin on 09/27/2007 09:27 am
Post by: RHAnthony on 09/27/2007 09:28 am
Post by: RHAnthony on 09/27/2007 09:28 am
Post by: moose on 09/27/2007 09:29 am
Post by: Chris Bergin on 09/27/2007 09:29 am
Quote
RHAnthony - 27/9/2007 10:28 AM
1128z to 1133z is a NO GO for launch, to avoid collision with ISS !!
Yeah...wouldn't be the best thing to happen, ever ;)
Post by: moose on 09/27/2007 09:31 am
Post by: RHAnthony on 09/27/2007 09:32 am
"hey guys.... um.... uh... guys!!!" hehehe
Good to know someone planned for the window!
Post by: RHAnthony on 09/27/2007 09:34 am
Post by: RHAnthony on 09/27/2007 09:35 am
Post by: RHAnthony on 09/27/2007 09:37 am
Post by: Chris Bergin on 09/27/2007 09:39 am
Post by: Terry Rocket on 09/27/2007 09:44 am
Quote
SimonShuttle - 27/9/2007 10:02 AM
I see Sky and BBC aren't bothering with this launch. Strange as they covered everything including the Cloudsat launch, and of course anything Shuttle, but this ain't getting any interest :-/
Ironic, seen as they always tend to get some 'astronomer' in during Shuttle launches, to which he's usually totally clueless (given astronomy's got nothing to do with space flight).
Post by: Chris Bergin on 09/27/2007 09:46 am
Post by: RHAnthony on 09/27/2007 09:51 am
Post by: RHAnthony on 09/27/2007 09:54 am
Post by: Chris Bergin on 09/27/2007 09:56 am
Post by: MKremer on 09/27/2007 09:58 am
Quote
Chris Bergin - 27/9/2007 4:56 AM
They need to turn the loop up. It's hardly audible.
It's audible on the AE Vid channel 2 feed (no NASA PAO, either).
Post by: RHAnthony on 09/27/2007 10:02 am
did anyone hear a quick "40" on the loop their listening too?
Post by: MKremer on 09/27/2007 10:03 am
(the N-TV feed is about 15 seconds behind the Real, which in turn is about 20-25 seconds behind real-time)
Post by: Chris Bergin on 09/27/2007 10:12 am
Quote
RHAnthony - 27/9/2007 11:02 AM
it's audible as anything in here... lol, and i think i just spoke on the wrong loop :) hahaha
did anyone hear a quick "40" on the loop their listening too?
Heh, was that you?
Post by: Chris Bergin on 09/27/2007 10:16 am
Post by: RHAnthony on 09/27/2007 10:17 am
Quote
Chris Bergin - 27/9/2007 3:12 PMQuoteRHAnthony - 27/9/2007 11:02 AM
it's audible as anything in here... lol, and i think i just spoke on the wrong loop :) hahaha
did anyone hear a quick "40" on the loop their listening too?
Heh, was that you?
Hehehe, i was hoping no one heard it... yes! I was trying to raise Canberra Australia (call sign 40) on their dedicated voice loop but the button on my panel was sticky and didn't click over hahaha oops!
Post by: Chris Bergin on 09/27/2007 10:19 am
Post by: Chris Bergin on 09/27/2007 10:31 am
Post by: Chris Bergin on 09/27/2007 10:36 am
Post by: EirikV on 09/27/2007 10:56 am
Post by: Chris Bergin on 09/27/2007 10:56 am
Dawn break, no pun intended:
Post by: Chris Bergin on 09/27/2007 11:00 am
Post by: Chris Bergin on 09/27/2007 11:01 am
Post by: Chris Bergin on 09/27/2007 11:03 am
Post by: star2 on 09/27/2007 11:06 am
Post by: Chris Bergin on 09/27/2007 11:06 am
Coming up to the built in hold at T-4 minutes.
Post by: Chris Bergin on 09/27/2007 11:07 am
Post by: Chris Bergin on 09/27/2007 11:08 am
Post by: EirikV on 09/27/2007 11:08 am
Post by: Chris Bergin on 09/27/2007 11:10 am
Switch not operational on loading (not clear where) - registering 99 percent and not 100 percent.
Post by: Chris Bergin on 09/27/2007 11:10 am
Post by: Chris Bergin on 09/27/2007 11:12 am
Post by: stockman on 09/27/2007 11:14 am
Post by: Chris Bergin on 09/27/2007 11:14 am
L-5 minutes. Let's keep the non-related chatter down. Images and updates only.
Post by: rosbif73 on 09/27/2007 11:15 am
Quote
Chris Bergin - 27/9/2007 1:03 PM
Another call for help with screenshots if anyone is willing...
Not much worthy of new screenshots for now, but I'll see what I can do immediately before/after liftoff.
Post by: DaveS on 09/27/2007 11:15 am
Post by: Chris Bergin on 09/27/2007 11:15 am
Post by: EirikV on 09/27/2007 11:16 am
Post by: punkboi on 09/27/2007 11:16 am
Where're those F-15's when you need 'em? :bleh:
Ship within SRB dropping area
Post by: Chris Bergin on 09/27/2007 11:18 am
Ship in the area where the solids are expected to splashdown. Five minutes to new T-0 estimate.
Coastguard in contact with the ship. Hopefully telling it's captain to get the f--- out of the way :)
Post by: EirikV on 09/27/2007 11:19 am
Post by: RHAnthony on 09/27/2007 11:19 am
Post by: RHAnthony on 09/27/2007 11:21 am
Post by: TJL on 09/27/2007 11:22 am
Post by: Chris Bergin on 09/27/2007 11:23 am
Post by: Chris Bergin on 09/27/2007 11:24 am
Post by: ntschke on 09/27/2007 11:24 am
BTW, Directv just fired up its first batch of new HD channels yesterday (21 additional, with more coming next month). Does anyone know if NASA TV HD is slated to be on the final list of 100+ channels?
Post by: DaveS on 09/27/2007 11:26 am
Quote
ntschke - 27/9/2007 1:24 PMYes. I believe the fines are on the order of 250,000 USD, with some serious jail time possible.
OK, some drunken charter boat captain fell asleep at the wheel. Do they get fined for the range violation? I'm sure an extra 10 minutes adds exponentially to the costs...
Post by: rosbif73 on 09/27/2007 11:27 am
Post by: Chris Bergin on 09/27/2007 11:27 am
Post by: RHAnthony on 09/27/2007 11:28 am
Post by: Analyst on 09/27/2007 11:29 am
Analyst
Post by: Chris Bergin on 09/27/2007 11:29 am
Post by: Chris Bergin on 09/27/2007 11:30 am
Post by: RHAnthony on 09/27/2007 11:30 am
Post by: punkboi on 09/27/2007 11:30 am
Quote
Analyst - 27/9/2007 4:29 AM Nice to have a launch window lasting for half an hour and not having one or two 1 second windows like on many interplanetary and polar Delta 2 missions. Analyst
Like Phoenix. Hold released
Post by: Antares on 09/27/2007 11:31 am
Post by: Chris Bergin on 09/27/2007 11:31 am
Post by: RHAnthony on 09/27/2007 11:32 am
Post by: Chris Bergin on 09/27/2007 11:32 am
Go for launch.
Post by: Chris Bergin on 09/27/2007 11:33 am
Range is go. Weather is go. LOX topping to 100 percent.
Post by: RHAnthony on 09/27/2007 11:34 am
Post by: Chris Bergin on 09/27/2007 11:35 am
Post by: rosbif73 on 09/27/2007 11:35 am
Post by: Chris Bergin on 09/27/2007 11:36 am
Post by: Chris Bergin on 09/27/2007 11:36 am
Post by: rosbif73 on 09/27/2007 11:36 am
Post by: Chris Bergin on 09/27/2007 11:37 am
Post by: Chris Bergin on 09/27/2007 11:37 am
Post by: RHAnthony on 09/27/2007 11:37 am
Post by: Satori on 09/27/2007 11:38 am
Post by: RHAnthony on 09/27/2007 11:38 am
Post by: rosbif73 on 09/27/2007 11:38 am
Post by: Chris Bergin on 09/27/2007 11:38 am
Post by: RHAnthony on 09/27/2007 11:38 am
Post by: Chris Bergin on 09/27/2007 11:39 am
1-2 sep. Second stage ignition.
Faring jettison.
Post by: RHAnthony on 09/27/2007 11:39 am
Post by: RHAnthony on 09/27/2007 11:40 am
Post by: Chris Bergin on 09/27/2007 11:43 am
102 miles altitude.
Heading to orbital velocity.
Marc: "on the ride upstairs"
Post by: Chris Bergin on 09/27/2007 11:44 am
Post by: ntschke on 09/27/2007 11:44 am
http://www.nasa.gov/home/hqnews/2006/mar/HQ_06129_HDnet.html
Post by: RHAnthony on 09/27/2007 11:44 am
Post by: Chris Bergin on 09/27/2007 11:44 am
Post by: punkboi on 09/27/2007 11:46 am
Post by: Chris Bergin on 09/27/2007 11:49 am
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9986
Post by: clongton on 09/27/2007 11:51 am
Quote
Chris Bergin - 27/9/2007 7:49 AM
Launch video:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9986
Great coverage once again. Thanks Chris
Post by: Chris Bergin on 09/27/2007 12:03 pm
Post by: Chris Bergin on 09/27/2007 12:04 pm
Post by: RHAnthony on 09/27/2007 12:05 pm
Post by: Martin FL on 09/27/2007 12:05 pm
Post by: infocat13 on 09/27/2007 12:09 pm
It has to do with the vehicle stabilizing itself after the solids jettison I believe
Post by: Analyst on 09/27/2007 12:10 pm
Quote
Martin FL - 27/9/2007 2:05 PM
What does Marc mean when he says the vehicle is recovering from transients, right after launch? Heard that before.
Disturbances from liftoff or staging. Guidance is bringing the vehicle back on track.
Analyst
Post by: Martin FL on 09/27/2007 12:10 pm
Quote
infocat13 - 27/9/2007 7:09 AM
It has to do with the vehicle stabelizing itself after the solids jetisen I believe
He says it at about T+10 seconds, not after solids jettison.
Ah, thanks Analyst.
Post by: RHAnthony on 09/27/2007 12:13 pm
Post by: Analyst on 09/27/2007 12:26 pm
Analyst
Post by: Chris Bergin on 09/27/2007 12:28 pm
Post by: Analyst on 09/27/2007 12:29 pm
Analyst
Post by: Chris Bergin on 09/27/2007 12:29 pm
Post by: Chris Bergin on 09/27/2007 12:30 pm
Post by: Chris Bergin on 09/27/2007 12:30 pm
Post by: Chris Bergin on 09/27/2007 12:31 pm
Post by: Chris Bergin on 09/27/2007 12:32 pm
Third stage burnout.
Post by: Chris Bergin on 09/27/2007 12:34 pm
Marc's got an audience.
Post by: Chris Bergin on 09/27/2007 12:37 pm
Congrats to all concerned!
Post by: Chris Bergin on 09/27/2007 12:37 pm
Post by: punkboi on 09/27/2007 12:38 pm
Post by: Chris Bergin on 09/27/2007 12:38 pm
Post by: Nick L. on 09/27/2007 12:58 pm
Post by: Antares on 09/27/2007 01:44 pm
Post by: jacqmans on 09/27/2007 01:45 pm
CAPE CANAVERAL, Fla. - NASA's Dawn spacecraft began its 1.7 billion
mile journey through the inner solar system to study a pair of
asteroids Thursday at 7:34 a.m. EDT.
The Delta 2 rocket, fitted with nine strap-on solid-fuel boosters,
safely climbed away from the Florida coastline and launch complex 17B
at the Cape Canaveral Air Force Station. "We have our time machine up
and flying," said Dawn Principal Investigator Christopher Russell of
the University of California, Los Angeles.
Dawn is scheduled to begin its exploration of Vesta in 2011 and Ceres
in 2015. The two icons of the asteroid belt are located in orbit
between Mars and Jupiter and have been witness to so much of our
solar system's history.
By using the same set of instruments at two separate destinations,
scientists can more accurately formulate comparisons and contrasts.
Dawn's science instrument suite will measure shape, surface
topography and tectonic history, elemental and mineral composition as
well as seek out water-bearing minerals.
A critical milestone for the spacecraft comes in is acquiring its
signal. The launch team expects that to occur in approximately 2-3
hours.
For the latest information about Dawn and its mission, visit:
http://www.nasa.gov/dawn
Post by: cabbage on 09/27/2007 02:08 pm
Telling you that now is slightly irrelevant though - but it's good to see the coverage.
Post by: John44 on 09/27/2007 02:14 pm
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2858&Itemid=1
Launch Replays
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2870&Itemid=1
Post by: Analyst on 09/27/2007 02:18 pm
Analyst
Post by: Antares on 09/27/2007 02:38 pm
Quote
cabbage - 27/9/2007 9:08 AMIsn't there some big EU tie-in with the propellant system? At the NASA night at the Lunar and Planetary Science Conference in March 2006, there were several Europeans up in arms about the mission being canceled so late in the game.
Just as an aside, BBC News 24 did manage to squeeze in the launch (despite the various holds and delays) and the first two minutes or so of flight (and they left the original audio in for the last 30 seconds of countdown and the first part of ascent). The mission even got a couple of minutes on the BBC1 one o'clock news bulletin :)
Telling you that now is slightly irrelevant though - but it's good to see the coverage.
Post by: ApolloLee on 09/27/2007 03:26 pm
Quote
Chris Bergin - 27/9/2007 4:18 AM
Dawn back on external power.
Ship in the area where the solids are expected to splashdown. Five minutes to new T-0 estimate.
Coastguard in contact with the ship. Hopefully telling it's captain to get the f--- out of the way :)
Another curiosity question... The Delta IV SRBS aren't recovered and just sink to the bottom, correct?
Post by: cabbage on 09/27/2007 03:27 pm
Edit: as far as the news coverage, it didn't reflect a "European" angle on it all (it was described as a Nasa probe) - just as a science mission that was travelling a long way to do something interesting. Their interviewee mentioned all the delays (including the range violation, so he was obviously following the launch reasonably closely) but that wasn't really the focus of it. It was a certainly a positive rather than negative report.
Post by: DaveS on 09/27/2007 03:28 pm
Quote
ApolloLee - 27/9/2007 5:26 PMYes. The only solids that are recovered is the Shuttle SRBs. They are unique in this way.
Another curiosity question... The Delta IV SRBS aren't recovered and just sink to the bottom, correct?
Post by: edkyle99 on 09/27/2007 03:48 pm
Quote
Chris Bergin - 27/9/2007 6:15 AM
Problem. New T-0 being worked. Range issue (someone get that boat out of the damn way)
I was wondering about this. It seems that there is no international law that provides any penalty for entering these drop zones, which are, after all, in international waters ruled by no one (presuming that this range halt was caused by an intrusion outside of U.S. territorial waters). A Notice to Mariners is posted, but ships have a "right of innocent passage". Some ships may not receive the notice while in transit, and, I suppose, other ships might choose to enter the zones regardless.
- Ed Kyle
Post by: Chris Bergin on 09/27/2007 04:58 pm
Quote
edkyle99 - 27/9/2007 4:48 PMQuoteChris Bergin - 27/9/2007 6:15 AM
Problem. New T-0 being worked. Range issue (someone get that boat out of the damn way)
I was wondering about this. It seems that there is no international law that provides any penalty for entering these drop zones, which are, after all, in international waters ruled by no one (presuming that this range halt was caused by an intrusion outside of U.S. territorial waters). A Notice to Mariners is posted, but ships have a "right of innocent passage". Some ships may not receive the notice while in transit, and, I suppose, other ships might choose to enter the zones regardless.
- Ed Kyle
Here's a question I've always wondered about...isn't there an exclusion zone buffer outside the downrange, where a ship can be told to change course before it actually enters the range, like this one did?
Maybe there's shipping routes nearby, making this accidential trip into the zone something that has little notice?
Post by: John44 on 09/27/2007 07:20 pm
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=2860&Itemid=1
Post by: WHAP on 09/27/2007 07:30 pm
Quote
Chris Bergin - 27/9/2007 10:58 AMQuoteedkyle99 - 27/9/2007 4:48 PMQuoteChris Bergin - 27/9/2007 6:15 AM
Problem. New T-0 being worked. Range issue (someone get that boat out of the damn way)
I was wondering about this. It seems that there is no international law that provides any penalty for entering these drop zones, which are, after all, in international waters ruled by no one (presuming that this range halt was caused by an intrusion outside of U.S. territorial waters). A Notice to Mariners is posted, but ships have a "right of innocent passage". Some ships may not receive the notice while in transit, and, I suppose, other ships might choose to enter the zones regardless.
- Ed Kyle
Here's a question I've always wondered about...isn't there an exclusion zone buffer outside the downrange, where a ship can be told to change course before it actually enters the range, like this one did?
Maybe there's shipping routes nearby, making this accidential trip into the zone something that has little notice?
More importantly, Port Canaveral is close by. I don't even think there's a state or federal law that applies any significant penalties for violations. Many of us remember the same fiasco on Atlas/Centaur 201 (the first Atlas III) where launch was scrubbed due to boats from a fishing tournament in the area. They were not in international waters - we had some camera views of small craft getting a lot of downwash from Blackhawks trying to get them going. And at least one boat was still not motivated to move very quickly.
Post by: eeergo on 10/09/2007 09:29 pm
Post by: punkboi on 10/29/2007 06:47 am
Testing, testing and more testing continues:
Post by: punkboi on 11/29/2007 05:56 pm
"Where is Dawn?" page now up:
Post by: jacqmans on 11/21/2008 12:00 pm
Nov. 20, 2008
JPL's Dawn spacecraft shut down its ion propulsion system today as scheduled. The spacecraft is now gliding toward a Mars flyby in February of next year.
"Dawn has completed the thrusting it needs to use Mars for a gravity assist to help get us to Vesta," said Marc Rayman, Dawn's chief engineer, of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Dawn will now coast in its orbit around the sun for the next half a year before we again fire up the ion propulsion system to continue our journey to the asteroid belt."
Dawn's ion engines may get a short workout next January to provide any final orbital adjustments prior to its encounter with the Red Planet. Ions are also scheduled to fly out of the propulsion system during some systems testing in spring. But mostly, Dawn's three ion engines will remain silent until June, when they will again speed Dawn toward its first appointment, with asteroid Vesta.
Dawn's ion engines are vital to the success of the misson's 8-year, 4.9-billion-kilometer (3-billion-mile) journey to asteroid Vesta and dwarf planet Ceres. One of these extremely frugal powerhouses can generate more than 24 hours of thrusting while consuming about .26 kilograms (about 9 ounces) of the spacecraft's xenon fuel supply -- less than the contents of a can of soda. Over their lifetime, Dawn's three ion propulsion engines will fire cumulatively for about 50,000 hours (over five years) -- a record for spacecraft.
Dawn will begin its exploration of asteroid Vesta in 2011 and the dwarf planet Ceres in 2015. These two icons of the asteroid belt have been witness to so much of our solar system's history. By utilizing the same set of instruments at two separate destinations, scientists can more accurately formulate comparisons and contrasts. Dawn's science instrument suite will measure shape, surface topography, tectonic history, elemental and mineral composition, and will seek out water-bearing minerals. In addition, the Dawn spacecraft itself and how it orbits both Vesta and Ceres will be used to measure the celestial bodies' masses and gravity fields.
The Dawn mission to asteroid Vesta and dwarf planet Ceres is managed and operated by JPL for NASA's Science Mission Directorate, Washington, D.C. The University of California, Los Angeles, is responsible for overall Dawn mission science. Other scientific partners include: Max Planck Institute for Solar System Research, Katlenburg, Germany; DLR Institute for Planetary Research, Berlin, Germany; Italian National Institute for Astrophysics, Rome; and the Italian Space Agency. Orbital Sciences Corporation of Dulles, Virginia, designed and built the Dawn spacecraft.
Additional information about Dawn is online at http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov.
-end-
Post by: Robotbeat on 02/25/2011 06:29 pm
Only 146 days left to go (roughly) until arrival at Vesta!!!
Post by: jacqmans on 03/10/2011 07:23 pm
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-075&cid=release_2011-075
There is an old chestnut about a pedestrian who once asked a virtuoso violinist near Carnegie Hall how to get to the famed concert venue. The virtuoso's answer: practice!
The same applies to NASA's Dawn mission to the giant asteroid Vesta. In the lead-up to orbiting the second most massive body in the asteroid belt this coming July, Dawn mission planners and scientists have been practicing mapping Vesta's surface, producing still images and a rotating animation that includes the scientists' best guess to date of what the surface might look like.
The animation and images incorporate the best data on the dimples and bulges of Vesta from ground-based telescopes and NASA's Hubble Space Telescope. The The topography is color-coded by altitude. The cratering and small-scale surface variations are computer-generated, based on the patterns seen on Earth's moon, an inner solar system object with a surface appearance that may be similar to Vesta.
"We won't know what Vesta really looks like until Dawn gets there," said Carol Raymond, Dawn's deputy principal investigator, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif., who helped orchestrate the activity. "But we needed a way to make sure our imaging plans would give us the best results possible. The products have proven that Dawn's mapping techniques will reveal a detailed view of this world that we've never seen up close before."
Vesta is one of the brightest asteroids in the night sky. Under the right conditions, Vesta can be seen with binoculars. But the best images so far from ground-based telescopes and Hubble still show Vesta as a bright, mottled orb. Once in orbit around Vesta, Dawn will pass about 650 kilometers (400 miles) above the asteroid's surface, snapping multi-angle images that will allow scientists to produce topographic maps. Later, Dawn will orbit at a lower altitude of about 200 kilometers (120 miles), getting closer shots of parts of the surface.
The Dawn mission will have the capability to map 80 percent of the asteroid's surface in the year the spacecraft is in orbit around Vesta. (The north pole will be dark when Dawn arrives in July 2011 and is expected to be only dimly lit when Dawn leaves in July 2012.) The mission will map Vesta at a spatial resolution on the order of the best global topography maps of Earth made by NASA's Shuttle Radar Topography mission.
Vesta formed very early in the history of the solar system and has one of the oldest surfaces in the system. Scientists are eager to get their first close-up look so they can better understand this early chapter.
Starting in August 2009, Dawn's optical navigation lead, Nick Mastrodemos, based at JPL, developed a computer simulation of the orbits and images to be taken by the spacecraft. He adapted software developed by Bob Gaskell of the Planetary Science Institute, Tuscon, Ariz. Mastrodemos created a model using scientists' best knowledge of Vesta and simulated the pictures that Dawn would take from the exact distances and geometries in the Dawn science plan.
He sent those images to two teams that use different techniques to derive topographical heights from imaging. One, led by Thomas Roatsch, was based at the Institute of Planetary Research of the German Aerospace Center (DLR) in Berlin. The other, led by Gaskell, was based at the Planetary Science Institute in Tuscon. (Like the Roatsch team, the Gaskell team did not have prior knowledge of the model from which the simulated data were created.) The groups sent their digital terrain models back to JPL, including the video produced by Frank Preusker from DLR that is based on his full stereo processing.
Mastrodemos compared their products to the original model he made. Both techniques reproduced the known data set well with only minor differences in spatial resolution and height accuracy. "Working through this exercise, the mission planners and the scientists learned that we could improve the overall accuracy of the topographic reconstruction, using a somewhat different observation geometry," Mastrodemos said. "Since then, Dawn science planners have worked to tweak the plans to implement the lessons of the exercise."
The exercise helped both teams get an early start on updating their software and planning the necessary computer resources. "In order to plan for proper stereo coverage of an unknown body like Vesta, practice is essential," said Roatsch, who is responsible for the framing camera team's stereo observation planning.
For now, the Virtual Vesta exercise gives the Dawn science team a fleshed-out model to consider. But to see whether their educated guesses were right, the team will have to wait until Dawn arrives at its target in four months.
The Dawn mission to Vesta and Ceres is managed for NASA's Science Mission Directorate in Washington by JPL, a division of the California Institute of Technology in Pasadena, and is a project of the Discovery Program managed at NASA's Marshall Space Flight Center, Huntsville, Ala. UCLA is home of the mission's principal investigator, Christopher Russell, and is responsible for overall Dawn mission science. The Dawn framing cameras have been developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The framing camera project is funded by the Max Planck Society, DLR and NASA.
To learn more about Dawn and its mission to the asteroid belt, and to see the new visuals, visit: http://www.nasa.gov/dawn or http://dawn.jpl.nasa.gov
Post by: short on 04/26/2011 06:53 am
Possibly they don’t have pictures with better then Hubble resolution yet; even though Dawn is less than one hundredth of an astronomical unit away now. It shouldn’t be too long now though. The arrival countdown is no longer up, but mid July is only about 75 days away.
Post by: ugordan on 04/26/2011 08:44 am
Post by: Robotbeat on 04/26/2011 05:03 pm
Yes, Dawn doesn't carry a powerful narrow-angle camera, rather it has more wide-angle cameras. I think the plan is to start imaging in May.I can't wait!!! :)
(Especially Ceres! WOOO! :) )
Post by: ugordan on 04/26/2011 05:09 pm
Post by: yg1968 on 04/26/2011 06:41 pm
http://en.wikipedia.org/wiki/4_Vesta
Quote
Vesta's shape is relatively close to a gravitationally relaxed oblate spheroid, but the large concavity and protrusion at the pole (see 'Surface features' below) combined with a mass less than 5×1020 kg precluded Vesta from automatically being considered a dwarf planet under International Astronomical Union (IAU) Resolution XXVI 5. Vesta may be listed as a dwarf planet in the future, if it is convincingly determined that its shape, other than the large impact basin at the southern pole, is due to hydrostatic equilibrium, as currently believed.
Post by: jacqmans on 05/03/2011 08:12 pm
NASA DAWN SPACECRAFT REACHES MILESTONE APPROACHING ASTEROID
Dwayne C. Brown
Headquarters, Washington
202-358-1726
[email protected]
Jia-Rui Cook
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0850
[email protected]
WASHINGTON -- NASA's Dawn spacecraft has reached its official approach
phase to the asteroid Vesta and will begin using cameras for the
first time to aid navigation for an expected July 16 orbital
encounter. The large asteroid is known as a protoplanet - a celestial
body that almost formed into a planet.
At the start of this three-month final approach to this massive body
in the asteroid belt, Dawn is 752,000 miles (1.21 million kilometers)
from Vesta, or about three times the distance between the Earth and
the moon. During the approach phase, the spacecraft's main activity
will be thrusting with a special, hyper-efficient ion engine that
uses electricity to ionize and accelerate xenon to generate thrust.
The 12-inch-wide ion thrusters provide less thrust than conventional
engines, but will provide propulsion for years during the mission and
provide far greater capability to change velocity.
"We feel a little like Columbus approaching the shores of the New
World," said Christopher Russell, Dawn principal investigator, based
at the University of California in Los Angeles (UCLA). "The Dawn team
can't wait to start mapping this Terra Incognita."
Dawn previously navigated by measuring the radio signal between the
spacecraft and Earth, and used other methods that did not involve
Vesta. But as the spacecraft closes in on its target, navigation
requires more precise measurements. By analyzing where Vesta appears
relative to stars, navigators will pin down its location and enable
engineers to refine the spacecraft's trajectory. Using its ion engine
to match Vesta's orbit around the sun, the spacecraft will spiral
gently into orbit around the asteroid. When Dawn gets approximately
9,900 miles (16,000 kilometers) from Vesta, the asteroid's gravity
will capture the spacecraft in orbit.
"After more than three and a half years of interplanetary travel, we
are finally closing in on our first destination," said Marc Rayman,
Dawn's chief engineer, at NASA's Jet Propulsion Laboratory (JPL) in
Pasadena, Calif. "We're not there yet, but Dawn will soon bring into
focus an entire world that has been, for most of the two centuries
scientists have been studying it, little more than a pinpoint of
light."
Scientists will search the framing camera images for possible moons
around Vesta. None of the images from ground-based and Earth-orbiting
telescopes have seen any moons, but Dawn will give scientists much
more detailed images to determine whether small objects have gone
undiscovered.
The gamma ray and neutron detector instrument also will gather
information on cosmic rays during the approach phase, providing a
baseline for comparison when Dawn is much closer to Vesta.
Simultaneously, Dawn's visible and infrared mapping spectrometer will
take early measurements to ensure it is calibrated and ready when the
spacecraft enters orbit around Vesta.
Dawn's odyssey, which will take it on a 3-billion-mile journey, began
on Sept. 27, 2007, with its launch from Cape Canaveral Air Force
Station in Florida. It will stay in orbit around Vesta for one year.
After another long cruise phase, Dawn will arrive at its second
destination, an even more massive body in the asteroid belt called
Ceres, in 2015.
These two icons of the asteroid belt will help scientists unlock the
secrets of our solar system's early history. The mission will compare
and contrast the two giant asteroids, which were shaped by different
forces. Dawn's science instrument suite will measure surface
composition, topography and texture. In addition, the Dawn spacecraft
will measure the tug of gravity from Vesta and Ceres to learn more
about their internal structures.
The Dawn mission to Vesta and Ceres is managed by JPL for NASA's
Science Mission Directorate (SMD) in Washington. Dawn is a project of
SMD's Discovery Program, which is managed by NASA's Marshall Space
Flight Center in Huntsville, Ala. UCLA is responsible for overall
Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed
and built the Dawn spacecraft. The framing cameras have been
developed and built under the leadership of the Max Planck Institute
for Solar System Research in Katlenburg-Lindau in Germany, with
significant contributions by the German Aerospace Center (DLR)
Institute of Planetary Research in Berlin, and in coordination with
the Institute of Computer and Communication Network Engineering in
Braunschweig. The framing camera project is funded by NASA, the Max
Planck Society and DLR.
For more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: ugordan on 05/03/2011 08:19 pm
Vesta should also be interesting. According to Wikipedia, there is a possibility that Vesta may be a dwarf planet.
I don't determine whether a body is interesting or not based on classification - "dwarf planet", etc. Ceres seems more interesting to me just because its surface appears to be more diverse than Vesta's.
Then again, all unexplored bodies can hide surprises. Vesta's place in the spotlight is certainly approaching fast. This is true exploration in this day and age. I can't wait.
Post by: jacqmans on 05/11/2011 03:10 pm
NASA DAWN SPACECRAFT CAPTURES FIRST IMAGE OF NEARING ASTEROID
WASHINGTON -- NASA's Dawn spacecraft has obtained its first image of
the giant asteroid Vesta, which will help fine-tune navigation during
its approach. Dawn expects to achieve orbit around Vesta on July 16,
when the asteroid is about 117 million miles from Earth.
The image from Dawn's framing cameras was taken on May 3 when the
spacecraft began its approach and was approximately 752,000 miles
(1.21 million km) from Vesta. The asteroid appears as a small, bright
pearl against a background of stars. Vesta also is known as a
protoplanet, because it is a large body that almost formed into a
planet.
"After plying the seas of space for more than a billion miles, the
Dawn team finally spotted its target," said Carol Raymond, Dawn's
deputy principal investigator at NASA's Jet Propulsion Laboratory
(JPL) in Pasadena, Calif. "This first image hints of detailed
portraits to come from Dawn's upcoming visit."
Vesta is 330 miles (530 km) in diameter and the second most massive
object in the asteroid belt. Ground- and space-based telescopes
obtained images of the bright orb for about two centuries, but with
little surface detail.
Mission managers expect Vesta's gravity to capture Dawn in orbit on
July 16. To enter orbit, Dawn must match the asteroid's path around
the sun, which requires very precise knowledge of the body's location
and speed. By analyzing where Vesta appears relative to stars in
framing camera images, navigators will pin down its location and
enable engineers to refine the spacecraft's trajectory.
Dawn will start collecting science data in early August at an altitude
of approximately 1,700 miles (2,700 km) above the asteroid's surface.
As the spacecraft gets closer, it will snap multi-angle images
allowing scientists to produce topographic maps. Dawn will later
orbit at approximately 120 miles (200 km) to perform other
measurements and obtain closer shots of parts of the surface. Dawn
will remain in orbit around Vesta for one year. After another long
cruise phase, Dawn will arrive in 2015 at its second destination,
Ceres, an even more massive body in the asteroid belt.
Gathering information about these two icons of the asteroid belt will
help scientists unlock the secrets of our solar system's early
history. The mission will compare and contrast the two giant
asteroids shaped by different forces. Dawn's science instruments will
measure surface composition, topography and texture. Dawn also will
measure the tug of gravity from Vesta and Ceres to learn more about
their internal structures. The spacecraft's full odyssey will take it
on a 3-billion-mile (5-billion-km) journey, which began with its
launch in September 2007.
Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science
Mission Directorate in Washington. Dawn is a project of the
directorate's Discovery Program, managed by NASA's Marshall Space
Flight Center in Huntsville, Ala.
The University of California in Los Angeles is responsible for overall
Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed
and built the spacecraft. The framing cameras were developed and
built under the leadership of the Max Planck Institute for Solar
System Research in Katlenburg-Lindau in Germany, with significant
contributions by the German Aerospace Center (DLR) Institute of
Planetary Research in Berlin and in coordination with the Institute
of Computer and Communication Network Engineering in Braunschweig.
The framing camera project is funded by NASA, the Max Planck Society
and DLR.
To view the image and obtain more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: bolun on 05/11/2011 04:49 pm
11 May 2011
http://www.dlr.de/en/desktopdefault.aspx/tabid-6221/10233_read-30643/
Post by: jacqmans on 06/13/2011 03:51 pm
NASA Spacecraft Captures Video of Asteroid Approach
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-179&cid=release_2011-179
PASADENA, Calif. – Scientists working with NASA's Dawn spacecraft have created a new video showing the giant asteroid Vesta as the spacecraft approaches this unexplored world in the main asteroid belt.
The video loops 20 images obtained for navigation purposes on June 1. The images show a dark feature near Vesta's equator moving from left to right across the field of view as Vesta rotates. Images also show Vesta's jagged, irregular shape, hinting at the enormous crater known to exist at Vesta's south pole.
To see the video, visit: http://www.nasa.gov/dawn .
The images were obtained by a framing camera during a 30-minute period and show about 30 degrees of a rotation. The pixel size in these images is approaching the resolution of the best Hubble Space Telescope images of Vesta.
"Like strangers in a strange land, we're looking for familiar landmarks," said Jian-Yang Li, a Dawn participating scientist from the University of Maryland, College Park. "The shadowy spot is one of those -- it appears to match a feature, known as 'Feature B,' from images of Vesta taken by NASA's Hubble Space Telescope."
Before orbiting Vesta on July 16, Dawn will gently slow down to about 75 mph (120 kilometers per hour). NASA is expecting to release more images on a weekly basis, with more frequent images available once the spacecraft begins collecting science at Vesta.
"Vesta is coming more and more into focus," said Andreas Nathues, framing camera lead investigator, based at the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany. "Dawn's framing camera is working exactly as anticipated."
The Dawn mission is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., for the agency's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the Dawn spacecraft. The framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germay. The German Aerospace Center (DLR) Institute of Planetary Research in Berlin made significant contributions in coordination with the Institute of Computer and Communication Network Engineering in Braunschweig. The framing camera project is funded by the Max Planck Society, DLR and NASA. JPL is a division of the California Institute of Technology in Pasadena.
For more information about Dawn, visit: http://www.nasa.gov/dawn . You can follow the mission on Twitter at: http://twitter.com/NASA_Dawn .
Post by: ugordan on 06/17/2011 08:45 pm
(http://www.dawn.mps.mpg.de/typo3temp/pics/image_KW24_01_e59b3726c7.jpg)
Post by: Robotbeat on 06/17/2011 09:17 pm
Getting closer, 265 000 km:Do you know where we can find raw images from Dawn, like we can for the MER rovers and MRO?
(http://www.dawn.mps.mpg.de/typo3temp/pics/image_KW24_01_e59b3726c7.jpg)
Post by: ugordan on 06/17/2011 09:18 pm
Post by: Robotbeat on 06/17/2011 09:21 pm
You can't, they're not released.I'm seeing that.
By the way, it'd be really cool to see an unmanned exploration L2 section!!!
Post by: jacqmans on 06/20/2011 05:41 pm
NASA HOSTS BRIEFING TO PREVIEW SPACECRAFT VISIT OF LARGE ASTEROID
WASHINGTON -- NASA will host a news briefing at 2 p.m. EDT on
Thursday, June 23, to discuss the Dawn spacecraft's year-long visit
to the large asteroid Vesta. The mission expects to go into orbit
around Vesta on July 16 and begin gathering science data in early
August. The briefing will be held in the NASA Headquarters auditorium
located at 300 E St. SW, in Washington. NASA Television and the
agency's website will broadcast the event.
Dawn's visit to Vesta will be the first prolonged encounter to a main
belt asteroid and the first trip to a protoplanet, or large body that
almost became a planet. Observations will help understand the
earliest chapter of our solar system's history.
The briefing panelists are:
-- W. James Adams, deputy director, Planetary Science Directorate,
NASA Headquarters
-- Robert Mase, Dawn project manager, Jet Propulsion Laboratory (JPL),
Pasadena, Calif.
-- Christopher Russell, Dawn principal investigator, UCLA
-- Carol Raymond, Dawn deputy principal investigator, JPL
Reporters may attend the event, ask questions from participating NASA
locations or join by phone. To obtain dial-in information,
journalists must e-mail Dwayne Brown at [email protected] with
their name, media affiliation and work telephone number by 11 a.m. on
June 23.
For more information about Dawn, visit:
http://www.nasa.gov/dawn
For NASA TV streaming video, downlink and schedule information, visit:
http://www.nasa.gov/ntv
The briefing also will be carried live on Ustream, with a live chat
box available, at
http://www.ustream.tv/nasajpl2
Post by: jacqmans on 06/23/2011 06:37 pm
NASA PROBE NEARS POSITION FOR YEAR-LONG STAY AT GIANT ASTEROID
WASHINGTON -- NASA's Dawn spacecraft is on track to begin the first
extended visit to a large asteroid. The mission expects to go into
orbit around Vesta on July 16 and begin gathering science data in
early August. Vesta resides in the main asteroid belt and is thought
to be the source of a large number of meteorites that fall to Earth.
"The spacecraft is right on target," said Robert Mase, Dawn project
manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif.
"We look forward to exploring this unknown world during Dawn's one
year stay in Vesta's orbit."
After traveling nearly four years and 1.7 billion miles (2.7 billion
kilometers), Dawn is approximately 96,000 miles (155,000 kilometers)
away from Vesta. When Vesta captures Dawn into its orbit, there will
be approximately 9,900 miles (16,000 kilometers) between them. They
will be approximately 117 million miles (188 million kilometers) away
from Earth.
After Dawn enters Vesta's orbit, engineers will need a few days to
determine the exact time of capture. Unlike other missions where a
dramatic, nail-biting propulsive burn results in orbit insertion
around a planet, Dawn has been using its placid ion propulsion system
to subtly shape its path for years to match Vesta's orbit around the
sun.
Images from Dawn's framing camera, taken for navigation purposes, show
the slow progress toward Vesta. They also show Vesta rotating about
65 degrees in the field of view. The images are about twice as sharp
as the best images of Vesta from NASA's Hubble Space Telescope, but
the surface details Dawn will obtain are still a mystery.
"Navigation images from Dawn's framing camera have given us intriguing
hints of Vesta, but we're looking forward to the heart of Vesta
operations, when we begin officially collecting science data," said
Christopher Russell, Dawn principal investigator, at the University
of California, Los Angeles (UCLA). "We can't wait for Dawn to peel
back the layers of time and reveal the early history of our solar
system."
Dawn's three instruments are all functioning and appear to be properly
calibrated. The visible and infrared mapping spectrometer, for
example, has started to obtain images of Vesta that are larger than a
few pixels in size. During the initial reconnaissance orbit, at
approximately 1,700 miles (2,700 kilometers), the spacecraft will get
a broad overview of Vesta with color pictures and data in different
wavelengths of reflected light. The spacecraft will move into a high
altitude mapping orbit, about 420 miles (680 kilometers) above the
surface to systematically map the parts of Vesta's surface
illuminated by the sun; collect stereo images to see topographic
highs and lows; acquire higher resolution data to map rock types at
the surface; and learn more about Vesta's thermal properties.
Dawn then will move even closer, to a low-altitude mapping orbit
approximately 120 miles (200 kilometers) above the surface. The
primary science goals of this orbit are to detect the byproducts of
cosmic rays hitting the surface and help scientists determine the
many kinds of atoms there, and probe the protoplanet's internal
structure. As Dawn spirals away from Vesta, it will pause again at
the high-altitude mapping orbit altitude. Because the sun's angle on
the surface will have progressed, scientists will be able to see
previously hidden terrain while obtaining different views of surface
features.
"We've packed our year at Vesta chock-full of science observations to
help us unravel the mysteries of Vesta," said Carol Raymond, Dawn's
deputy principal investigator at JPL. Vesta is considered a
protoplanet, or body that never quite became a full-fledged planet.
Dawn launched in September 2007. Following a year at Vesta, the
spacecraft will depart for its second destination, the dwarf planet
Ceres, in July 2012. Dawn's mission to Vesta and Ceres is managed by
JPL for NASA's Science Mission Directorate in Washington. Dawn is a
project of the directorate's Discovery Program, managed by NASA's
Marshall Space Flight Center in Huntsville, Ala.
UCLA is responsible for overall Dawn mission science. Orbital Sciences
Corp. of Dulles, Va., designed and built the spacecraft. The German
Aerospace Center, the Max Planck Institute for Solar System Research,
the Italian Space Agency and the Italian National Astrophysical
Institute are part of the mission team.
For more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: ugordan on 06/23/2011 06:42 pm
Post by: Robotbeat on 06/28/2011 04:44 pm
http://www.youtube.com/watch?v=FsupRGBaFOA
from here: http://www.dawn.mps.mpg.de/index.php?id=17&L=1&tx_ttnews%5Btt_news%5D=24&cHash=3d919c63d7813d258a989e6204be21bd (http://www.dawn.mps.mpg.de/index.php?id=17&L=1&tx_ttnews%5Btt_news%5D=24&cHash=3d919c63d7813d258a989e6204be21bd)
Post by: TheFallen on 07/02/2011 06:12 am
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_062411.asp
Post by: TheFallen on 07/07/2011 06:41 pm
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_070111.asp
Post by: Prober on 07/08/2011 05:59 pm
Post by: Robotbeat on 07/08/2011 06:09 pm
Any reports on how those Ion thrusters operated?Pretty darned well, or we wouldn't be looking at Vesta right now.
EDIT:There was a hickup, but nothing major. Actually will end up arriving at Vesta a little earlier as a result:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-206&rn=news.xml&rst=3063
Post by: Ben the Space Brit on 07/09/2011 05:13 pm
One thing I'm already interested to know is what the heck that bump in the lower hemesphere is. IIRC, radar maps show that there is a mean depression on Vesta's southern hemisphere, taking up more than 50% of that face of the asteroid (which I assumed to be the crater from from which the V-type meteorites came), with a large rise in the centre. Is that what I'm looking at here?
Post by: ugordan on 07/09/2011 05:35 pm
Post by: SpacemanInSPACE on 07/10/2011 11:26 am
There are no radar maps of Vesta and yes, it's thought to be a giant impact. Similar to a scar on Epimetheus, except on a much larger scale.
Correct me if I am wrong, are you saying that whatever impacted Vesta is gaping out from the surface?
Post by: ugordan on 07/10/2011 11:40 am
Post by: TheFallen on 07/11/2011 04:31 am
http://dawn.jpl.nasa.gov/mission/live_shots.asp
Post by: Ben the Space Brit on 07/11/2011 11:46 am
a relative speed of 130 mph from the asteroid
Only with an SEP could you get figures like that!
Post by: TheFallen on 07/13/2011 02:29 am
Post by: Robotbeat on 07/13/2011 04:14 am
Dawn is currently not thrusting... How awesome are the photos it's taking of Vesta right now? :)We'll find out Thursday (here: http://dawn.jpl.nasa.gov/multimedia/vesta_dawn_gallery.asp )! ;)
Post by: yg1968 on 07/14/2011 03:48 pm
http://www.nasa.gov/mission_pages/dawn/multimedia/dawn-image-070911.html
Post by: Prober on 07/14/2011 03:58 pm
Dawn is currently not thrusting... How awesome are the photos it's taking of Vesta right now? :)
I have alot of interest in the thruster system. How much fuel has been used, available?
Post by: TheFallen on 07/14/2011 04:58 pm
http://dawn.jpl.nasa.gov/mission/journal_01_30_11.asp
Post by: jacqmans on 07/14/2011 05:43 pm
NASA Spacecraft to Enter Asteroid's Orbit on July 15
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-208&cid=release_2011-208
PASADENA, Calif. -- On July 15, NASA's Dawn spacecraft will begin a prolonged encounter with the asteroid Vesta, making the mission the first to enter orbit around a main-belt asteroid.
The main asteroid belt lies between the orbits of Mars and Jupiter. Dawn will study Vesta for one year, and observations will help scientists understand the earliest chapter of our solar system's history.
As the spacecraft approaches Vesta, surface details are coming into focus, as seen in a recent image taken from a distance of about 26,000 miles (41,000 kilometers). The image is available at: http://www.nasa.gov/mission_pages/dawn/multimedia/dawn-image-070911.html .
Engineers expect the spacecraft to be captured into orbit at approximately 10 p.m. PDT Friday, July 15 (1 a.m. EDT Saturday, July 16). They expect to hear from the spacecraft and confirm that it performed as planned during a scheduled communications pass that starts at approximately 11:30 p.m. PDT on Saturday, July 16 (2:30 a.m. EDT Sunday, July 17). When Vesta captures Dawn into its orbit, engineers estimate there will be approximately 9,900 miles (16,000 kilometers) between them. At that point, the spacecraft and asteroid will be approximately 117 million miles (188 million kilometers) from Earth.
"It has taken nearly four years to get to this point," said Robert Mase, Dawn project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Our latest tests and check-outs show that Dawn is right on target and performing normally."
Engineers have been subtly shaping Dawn's trajectory for years to match Vesta's orbit around the sun. Unlike other missions, where dramatic propulsive burns put spacecraft into orbit around a planet, Dawn will ease up next to Vesta. Then the asteroid's gravity will capture the spacecraft into orbit. However, until Dawn nears Vesta and makes accurate measurements, the asteroid's mass and gravity will only be estimates. So the Dawn team will need a few days to refine the exact moment of orbit capture.
Launched in September 2007, Dawn will depart for its second destination, the dwarf planet Ceres, in July 2012. The spacecraft will be the first to orbit two bodies in our solar system.
Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are part of the mission team.
For a current image of Vesta and more information about the Dawn mission, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .You also can follow the mission on Twitter at: http://www.twitter.com/nasa_dawn .
Post by: Danderman on 07/16/2011 03:29 pm
"The US space agency says its Dawn probe should now be in orbit around the asteroid Vesta."
"Confirmation that Dawn is safely circling the rock should come on Sunday (GMT) when the probe is due to return data on its status."
Post by: marsavian on 07/16/2011 04:32 pm
Nasa expects to hear back from its Dawn spacecraft on Sunday to learn if the manoeuvre, which took place about 117 million miles from Earth, was successful.
"We just have to be patient," said chief engineer Marc Rayman of the Jet Propulsion Laboratory in Pasadena, California.
Post by: TheFallen on 07/17/2011 08:12 am
NASA's Dawn Spacecraft Enters Orbit Around Asteroid Vesta
PASADENA, Calif. -- NASA's Dawn spacecraft on Saturday became the first probe ever to enter orbit around an object in the main asteroid belt between Mars and Jupiter.
http://www.nasa.gov/mission_pages/dawn/news/dawn20110716.html
Post by: jacqmans on 07/18/2011 07:11 pm
NASA DAWN SPACECRAFT RETURNS CLOSE-UP IMAGE OF ASTEROID VESTA
PASADENA, Calif. -- NASA's Dawn spacecraft has returned the first
close-up image after beginning its orbit around the giant asteroid
Vesta. On Friday, July 15, Dawn became the first probe to enter orbit
around an object in the main asteroid belt between Mars and Jupiter.
The image taken for navigation purposes shows Vesta in greater detail
than ever before. When Vesta captured Dawn into its orbit, there were
approximately 9,900 miles (16,000 kilometers) between the spacecraft
and asteroid. Engineers estimate the orbit capture took place at 10
p.m. PDT.
Vesta is 330 miles (530 kilometers) in diameter and the second most
massive object in the asteroid belt. Ground- and space-based
telescopes have obtained images of Vesta for about two centuries, but
they have not been able to see much detail on its surface.
"We are beginning the study of arguably the oldest extant primordial
surface in the solar system," said Dawn principal investigator
Christopher Russell from the University of California, Los Angeles.
"This region of space has been ignored for far too long. So far, the
images received to date reveal a complex surface that seems to have
preserved some of the earliest events in Vesta's history, as well as
logging the onslaught that Vesta has suffered in the intervening
eons."
Vesta is thought to be the source of a large number of meteorites that
fall to Earth. Vesta and its new NASA neighbor are currently
approximately 117 million miles (188 million kilometers) away from
Earth. The Dawn team will begin gathering science data in August.
Observations will provide unprecedented data to help scientists
understand the earliest chapter of our solar system. The data also
will help pave the way for future human space missions.
After traveling nearly four years and 1.7 billion miles (2.8 billion
kilometers), Dawn also accomplished the largest propulsive
acceleration of any spacecraft, with a change in velocity of more
than 4.2 miles per second (6.7 kilometers per second), due to its ion
engines. The engines expel ions to create thrust and provide higher
spacecraft speeds than any other technology currently available.
"Dawn slipped gently into orbit with the same grace it has displayed
during its years of ion thrusting through interplanetary space," said
Marc Rayman, Dawn chief engineer and mission manager at NASA's Jet
Propulsion Laboratory (JPL) in Pasadena, Calif. "It is fantastically
exciting that we will begin providing humankind its first detailed
views of one of the last unexplored worlds in the inner solar
system."
Although orbit capture is complete, the approach phase will continue
for about three weeks. During approach the Dawn team will continue a
search for possible moons around the asteroid; obtain more images for
navigation; observe Vesta's physical properties; and obtain
calibration data.
In addition, navigators will measure the strength of Vesta's
gravitational tug on the spacecraft to compute the asteroid's mass
with much greater accuracy than has been previously available. That
will allow them to refine the time of orbit insertion.
Dawn will spend one year orbiting Vesta, then travel to a second
destination, the dwarf planet Ceres, arriving in February 2015. The
mission to Vesta and Ceres is managed by JPL for the agency's Science
Mission Directorate in Washington. Dawn is a project of the
directorate's Discovery Program, which is managed by NASA's Marshall
Space Flight Center in Huntsville, Ala.
UCLA is responsible for Dawn mission science. Orbital Sciences Corp.
of Dulles, Va., designed and built the spacecraft. The German
Aerospace Center, the Max Planck Institute for Solar System Research,
the Italian Space Agency and the Italian National Astrophysical
Institute are part of the mission's team.
To view the image and obtain more information about the Dawn mission,
visit:
http://www.nasa.gov/dawn
To follow the mission on Twitter, visit:
http://www.twitter.com/NASA_Dawn
-end-
Post by: Robotbeat on 07/18/2011 08:42 pm
Post by: Jason1701 on 07/18/2011 09:47 pm
Post by: yg1968 on 07/19/2011 06:14 am
Awesome!
Here is the link to the image:
http://www.nasa.gov/mission_pages/dawn/multimedia/pia14313.html
Post by: jacqmans on 07/20/2011 04:31 pm
AFTER FOUR-YEAR JOURNEY
-- Company’s Ion-Propelled Interplanetary Spacecraft Reaches One of the
Solar System’s Largest Asteroids Between Mars and Jupiter --
-- Dawn Provides First-Ever Close-Up Images of Arizona-Size Asteroid --
(Dulles, VA 20 July 2011) – Orbital Sciences Corporation (NYSE: ORB)
announced today that the Dawn interplanetary spacecraft, which the company
designed and built for NASA’s Jet Propulsion Laboratory (JPL), has
successfully completed rendezvous and achieved orbit around the solar
system’s second most massive asteroid, Vesta. These events took place
after a nearly four-year, 1.7 billion-mile journey to Vesta, which resides
in the main asteroid belt between Mars and Jupiter.
Dawn successfully entered orbit approximately 9,900 miles above Vesta’s
surface last Friday evening at approximately 10:00 p.m. PDT. Since
capture, the spacecraft has continued its gradual decent toward its initial
science survey orbit at an altitude of about 1,700 miles above Vesta. As
the mission progresses over the next year, it will descend to additional
science orbits at 425 miles and then 125 miles above the surface. Dawn
will image Vesta’s surface using Framing Cameras and carry out other
scientific surveys using a Visible and Infrared Mapping Spectrometer and a
Gamma-Ray and Neutron Detector. Dawn also will conduct a scientific survey
using its radio system (along with the NASA Deep Space Network) to map
Vesta’s gravity field. Dawn will continue to return science data about the
asteroid through July 2012, when it will depart Vesta to journey farther
out in the asteroid belt.
The Dawn mission will achieve a “first” in space exploration history when
it thrusts out of Vesta’s orbit and continues on its journey to rendezvous
in 2015 with Ceres, the solar system’s largest asteroid. Ceres was
recently reclassified as a dwarf planet, the same designation given to
Pluto. Dawn will become the first exploration spacecraft to rendezvous
with and orbit a planetary body and then transfer to and orbit a second
planetary body.
This “first” is made possible by the unique onboard ion propulsion system
developed by JPL, which Orbital incorporated into its spacecraft design.
The ion propulsion system uses electrical power, supplied by very large
solar arrays, to efficiently ionize the onboard xenon fuel and accelerate
the resulting plasma from rocket thrusters at very high velocities. The
resulting thrust, though of very small magnitude, is applied nearly
continuously through much of the mission and accelerates the spacecraft to
velocities about ten times that achievable by traditional chemical rockets.
The ion propulsion system is also used as a braking system to lower the
spacecraft altitude above Vesta. The spacecraft will rely on this
innovative propulsion system to escape from Vesta’s orbit and cruise to its
second destination, a rendezvous with Ceres. It will again be used as a
braking system to lower the orbit around Ceres.
To reach this important point in its mission, the Dawn spacecraft has
traveled over 1.7 billion miles in its path around the Sun. Included in
its journey was a close fly-by of Mars that utilized the red planet’s
gravitational field as a “slingshot” to accelerate the spacecraft and alter
its trajectory to reach its deep space destination. When Dawn’s eight-year
mission is complete, it will have traveled over 3.0 billion miles.
About the Dawn Spacecraft
The Dawn spacecraft is a medium-class spacecraft that weighed 1,218 kg
(2,685 lbs.) at the time of its launch in September 2007 from Cape
Canaveral, FL. It carried enough xenon propellant to enable it to change
its speed by more than 11 kilometers per second (almost seven miles per
second) over the course of the mission, far more than any other spacecraft
propulsion system has ever achieved. The solar arrays of the Dawn
spacecraft are also unusually large for a spacecraft of this size due to
the need to generate sufficient electrical power once the spacecraft has
reached Vesta and Ceres. The solar arrays measure approximately 20 meters
(65 feet) from tip to tip in their fully deployed configuration. Shortly
after its launch, when Dawn was still relatively close to Earth, it was
capable of generating over 10 kilowatts of power. The large solar arrays
will still generate nearly 1.5 kilowatts of power while orbiting Ceres,
despite being almost three times farther away from the Sun than at the
beginning of the mission.
About the Dawn Mission
The primary goal of the Dawn mission is to characterize the conditions and
processes of the solar system’s earliest epoch by investigating two of the
largest protoplanets remaining intact since their formation. Vesta and
Ceres orbit the Sun in an extensive zone between Mars and Jupiter called
the asteroid belt. These asteroids have followed very different
evolutionary paths constrained by the diversity of processes that operated
during the first epoch of solar system evolution.
The top-level question that the mission addresses is the role of size and
water in determining the evolution of the planets. Ceres and Vesta are
ideal bodies with which to address this question, as they are the most
massive of the protoplanets, baby planets whose growth was interrupted by
the formation of Jupiter. Vesta is considered to be an evolved and dry
body while Ceres is thought to be primitive and contain substantial water
ice. For more information about the Dawn mission, visit JPL’s Dawn mission
page at: http://dawn.jpl.nasa.gov/
Post by: Robotbeat on 07/23/2011 09:09 pm
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_071811.asp
Post by: robertross on 07/23/2011 09:35 pm
New image!
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_071811.asp
The waveness on the surface really is neat.
Post by: TheFallen on 07/24/2011 06:45 am
http://dawn.jpl.nasa.gov/mission/live_shots.asp
Post by: jacqmans on 07/27/2011 06:04 pm
NASA TO UNVEIL FULL-FRAME IMAGE OF VESTA AT NEWS CONFERENCE
WASHINGTON -- NASA will host a news conference on Monday, Aug. 1, at 2
p.m. EDT, to discuss the Dawn spacecraft's successful orbit insertion
around Vesta on July 15 and unveil the first full-frame images from
Dawn's framing camera. The news conference will be held in the Von
Karman auditorium at NASA's Jet Propulsion Laboratory (JPL), 4800 Oak
Grove Dr., Pasadena, Calif. Journalists also may ask questions from
participating NASA locations or join by phone. To obtain dial-in
information, journalists must contact JPL's Media Relations Office at
818-354-5011 by 9 a.m. PDT on Aug. 1.
NASA Television and the agency's website will broadcast the event. It
also will be carried live on Ustream, with a live chat box available,
at:
http://www.ustream.tv/nasajpl2
The news conference panelists are:
-- Colleen Hartman, assistant associate administrator, Science Mission
Directorate, NASA Headquarters, Washington
-- Charles Elachi, director, JPL
-- Marc Rayman, chief engineer and mission manager, JPL
-- Christopher Russell, Dawn principal investigator, University of
California, Los Angeles
-- Holger Sierks, framing camera team member, Max Planck Society,
Katlenburg-Lindau, Germany
-- Enrico Flamini, chief scientist, Italian Space Agency (ASI), Rome,
Italy
Although Dawn is collecting some science data now, the mission's
intensive collection of information will begin in early August.
Observations of the giant asteroid Vesta will provide unprecedented
data to help scientists understand the earliest chapter of our solar
system. Dawn is the first spacecraft to orbit an asteroid in the main
asteroid belt between Mars and Jupiter. After spending one year
orbiting Vesta, Dawn will travel to a second destination, the dwarf
planet Ceres, and arrive there in February 2015.
For more information about Dawn, visit:
http://www.nasa.gov/dawn
For NASA TV streaming video, downlink and schedule information, visit:
http://www.nasa.gov/ntv
Post by: Robotbeat on 07/29/2011 11:32 pm
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_072311.asp
July 28, 2011 - PASADENA, Calif. -- NASA's Dawn spacecraft obtained this image with its framing camera on July 23, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers) away from the giant asteroid Vesta.
Post by: Jason1701 on 07/29/2011 11:44 pm
Post by: alexw on 07/30/2011 05:58 am
It's almost like ... a real spaceship.
-Alex
PS: Jason1701, clever tagline. How do you write the Lagrangian?
Post by: Robotbeat on 07/30/2011 07:45 am
It keeps blowing my mind that Dawn's gonna take stunning pictures of Vesta, then *leave orbit*, and *thrust under constant acceleration* (for periods) before *going into orbit around a /different/ body*.And don't forget... Dawn will leave Ceres orbit (planetary protection) and may well venture to other asteroids, which haven't been decided. :)
It's almost like ... a real spaceship.
-Alex
PS: Jason1701, clever tagline. How do you write the Lagrangian?
Post by: Jason1701 on 07/31/2011 10:15 pm
Thanks, Alex. Which Lagrangian are you referring to?
Post by: jacqmans on 08/01/2011 04:22 pm
NASA'S DAWN SPACECRAFT BEGINS SCIENCE ORBITS OF VESTA
WASHINGTON -- NASA's Dawn spacecraft, the first ever to orbit an
object in the main asteroid belt, is spiraling toward its first of
four intensive science orbits. That initial orbit of the rocky world
Vesta begins Aug. 11, at an altitude of nearly 1,700 miles (2,700
kilometers) and will provide in-depth analysis of the asteroid. Vesta
is the brightest object in the asteroid belt as seen from Earth and
is thought to be the source of a large number of meteorites that fall
to Earth.
The Dawn team unveiled the first full-frame image of Vesta taken on
July 24:
http://go.nasa.gov/ohdkyh
This image was taken at a distance of 3,200 miles (5,200 kilometers).
Images from Dawn's framing camera, taken for navigation purposes and
as preparation for scientific observations, are revealing the first
surface details of the giant asteroid. These images go all the way
around Vesta, since the giant asteroid turns on its axis once every
five hours and 20 minutes.
"Now that we are in orbit around one of the last unexplored worlds in
the inner solar system, we can see that it's a unique and fascinating
place," said Marc Rayman, Dawn's chief engineer and mission manager
at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
After traveling nearly four years and 1.7 billion miles (2.8 billion
kilometers), Dawn has been captured by Vesta's gravity, and there
currently are 1,800 miles (2,900 kilometers) between the asteroid and
the spacecraft. The giant asteroid and its new neighbor are
approximately 114 million miles (184 million kilometers) away from
Earth.
"We have been calling Vesta the smallest terrestrial planet," said
Chris Russell, Dawn's principal investigator at the UCLA. "The latest
imagery provides much justification for our expectations. They show
that a variety of processes were once at work on the surface of Vesta
and provide extensive evidence for Vesta's planetary aspirations."
Engineers still are working to determine the exact time that Dawn
entered Vesta's orbit, but the team has reported an approximate orbit
insertion time of 9:47 p.m. PDT on July 15 (12:47 a.m. EDT on July
16).
In addition to the framing camera, Dawn's instruments include the
gamma ray and neutron detector and the visible and infrared mapping
spectrometer. The gamma ray and neutron detector uses 21 sensors with
a very wide field of view to measure the energy of subatomic
particles emitted by the elements in the upper yard (meter) of the
asteroid's surface. The visible and infrared mapping spectrometer
will measure the surface mineralogy of both Vesta and Dawn's next
target, the dwarf planet Ceres. The spectrometer is a modification of
a similar one flying on the European Space Agency's Rosetta and Venus
Express missions.
Dawn also will make another set of scientific measurements at Vesta
and Ceres using the spacecraft's radio transmitter in tandem with
sensitive antennas on Earth. Scientists will monitor signals from
Dawn and later Ceres to detect subtle variations in the objects'
gravity fields. These variations will provide clues about the
interior structure of these bodies by studying the mass distributed
in each gravity field.
"The new observations of Vesta are an inspirational reminder of the
wonders unveiled through ongoing exploration of our solar system,"
said Jim Green, planetary division director at NASA Headquarters in
Washington.
Dawn launched in September 2007. Following a year at Vesta, the
spacecraft will depart in July 2012 for Ceres, where it will arrive
in 2015. Dawn's mission to Vesta and Ceres is managed by JPL for
NASA's Science Mission Directorate in Washington. Dawn is a project
of the directorate's Discovery Program, managed by NASA's Marshall
Space Flight Center in Huntsville, Ala.
UCLA is responsible for overall Dawn mission science. Orbital Sciences
Corp. in Dulles, Va., designed and built the spacecraft. The German
Aerospace Center, the Max Planck Institute for Solar System Research,
the Italian Space Agency and the Italian National Astrophysical
Institute are international partners on the mission team.
For more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: knotnic on 08/01/2011 05:53 pm
Post by: robertross on 08/02/2011 01:33 am
This is incredibly cool. Don't miss the full rotation video: http://www.nasa.gov/multimedia/videogallery/index.html?collection_id=65362&media_id=104094441
Sweet! Thanks for the link
Post by: corrodedNut on 08/03/2011 08:53 pm
http://www.nasa.gov/mission_pages/dawn/multimedia/pia14323.html
http://www.nasa.gov/mission_pages/dawn/news/dawn20110801.html
Post by: kevin-rf on 08/04/2011 02:09 pm
Post by: ugordan on 08/04/2011 07:10 pm
Post by: Bubbinski on 08/07/2011 02:49 am
Post by: TheFallen on 08/08/2011 02:10 am
http://neo.jpl.nasa.gov/orbits/fullview4.jpg
Post by: racshot65 on 08/11/2011 09:15 pm
Quote
The Dawn spacecraft has completed a graceful spiral into the first of four planned science orbits during the spacecraft's yearlong visit to Vesta. The spacecraft started taking detailed observations on Aug. 11 at 9:13 a.m. PDT (12:13 a.m. EDT), which marks the official start of the first science-collecting orbit phase at Vesta, also known as the survey orbit.
...
http://www.jpl.nasa.gov/news/news.cfm?release=2011-250&cid=release_2011-250&msource=2011250&tr=y&auid=8803252 (http://www.jpl.nasa.gov/news/news.cfm?release=2011-250&cid=release_2011-250&msource=2011250&tr=y&auid=8803252)
Post by: racshot65 on 08/12/2011 05:58 pm
Quote
Dawn is now beginning intensive observations of the alien world it orbits. The approach phase, which began on May 3, is complete. Today Dawn is in its survey orbit around Vesta.
...
http://dawn.jpl.nasa.gov/mission/journal_08_11_11.asp
Post by: racshot65 on 08/13/2011 10:21 am
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_365888238.asp
Post by: lewis886 on 08/14/2011 01:09 am
http://www.youtube.com/watch?v=JmH-Gfplzk8
Post by: racshot65 on 08/14/2011 08:49 am
I put together this little news segment / mini-documentary mainly as a primer for people who know nothing about Vesta or Dawn, and put it up on Youtube. I don't know how interesting any of you will find it, since you already know far more than this segment explains, but still, here it is :) It's only about 3-1/2 min long.
http://www.youtube.com/watch?v=JmH-Gfplzk8
Thats really good :)
Post by: kkattula on 08/14/2011 04:16 pm
One of the best space-related videos I ever seen. You explain the mission clearly, in a way a non-expert could easily understand, but you don't dumb it down to the point of inaccuracy.
Kudos.
Post by: jjknap on 08/14/2011 04:27 pm
Post by: Robotbeat on 08/14/2011 06:41 pm
By the way, are there any real color images of Vesta from Dawn, yet?
Post by: racshot65 on 08/15/2011 04:49 pm
http://dawn.jpl.nasa.gov/multimedia/images/2f2_365891958_detail.jpg
Post by: lewis886 on 08/15/2011 07:30 pm
wow, kkattula, that's some pretty high praise. Thank you very much. That's what I was going for, making it easy for everyone to understand :) I wish I could have found more actual video footage (was hoping to find footage of the launch) but I didn't really find much that I could download. Oh well. I'm hoping to do some more of them.
Post by: robertross on 08/15/2011 10:32 pm
I put together this little news segment / mini-documentary mainly as a primer for people who know nothing about Vesta or Dawn, and put it up on Youtube. I don't know how interesting any of you will find it, since you already know far more than this segment explains, but still, here it is :) It's only about 3-1/2 min long.
Finally got time to watch it. Great job! Very clear and concise. That's the type of video I would hope they could play in science classes at schools.
Post by: baldusi on 08/15/2011 11:26 pm
Post by: racshot65 on 08/16/2011 10:37 am
http://dawn.jpl.nasa.gov/multimedia/images/3f2_365903669_detail.jpg
http://dawn.jpl.nasa.gov/multimedia/images/4f2_365906459_detail.jpg
Post by: racshot65 on 08/16/2011 08:11 pm
http://dawn.jpl.nasa.gov/multimedia/images/5f2_365886460_700.jpg
Post by: clongton on 08/16/2011 08:22 pm
Post by: racshot65 on 08/17/2011 07:59 pm
http://dawn.jpl.nasa.gov/multimedia/images/6f2_3658894444_700.jpg
Post by: robertross on 08/18/2011 01:12 am
These are very interesting - no doubt, and I can't say enough how much I appreciate you posting these. While I am sure that there is a significant number of members here for whom this rocky asteroid is of prime interest, my prime interest is yet to come. I am really looking forward to Dawn's visit to Ceres. I'm not sure just how much value Vesta is to the future of HSF, and I hope someone here will enlighten me on that, but Ceres could be of immense value if its composition turns out to be as predicted. If it really is an icy water world, then it could very well be the key to the exploration and settling of the inner solar system.
I certainly agree with having great anticipation for the Ceres visit: that should be a real treat.
Post by: racshot65 on 08/18/2011 01:12 pm
Quote
August 16, 2011
Dawn Completes Two Day Side Passes in Survey Orbit
Dawn has observed Vesta during two passes over the illuminated face of Vesta, each lasting about 34 hours. It acquired all the images planned with the camera.
After the visible and infrared mapping spectrometer (VIR) had successfully completed about 40% of it observations during the first orbit, its internal computer detected a temporary problem, so the rest were not performed. (As explained in the latest Dawn Journal, plans included collecting more data than needed, so missing the observations is easily tolerated.
During the subsequent communications session (while Dawn was over the night side), controllers verified the instrument was healthy and reconfigured it. VIR acquired all of the planned measurements during the second orbit. Scientists have confirmed that the data are of very high quality.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 08/26/2011 10:21 am
Quote
August 24, 2011
Dawn Completes Three More Day Side Passes in Survey Orbit
Dawn has now acquired images and spectra through a total of five passes over the lit side of Vesta, and the quality of the data remains excellent.
The visible and infrared mapping spectrometer (VIR) experienced an anomaly on the third orbit very similar to the one on the first orbit, and engineers and scientists from the instrument team in Italy and the operations team at JPL are continuing to work to understand it.
The principal scientific objective of survey orbit is to acquire 5000 sets of spectra with VIR. VIR has already returned well in excess of 8000. All other objectives for survey orbit have also been met, so this phase of the mission is set to conclude on schedule on August 31.
Post by: racshot65 on 08/30/2011 07:04 pm
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_311222876.asp
Post by: racshot65 on 08/31/2011 08:07 pm
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_355222480.asp
Post by: Robotbeat on 08/31/2011 08:08 pm
(Ah, saw your post at unmannedspaceflight.com, ugordon... http://www.unmannedspaceflight.com/index.php?s=&showtopic=7011&view=findpost&p=177719 )
really annoying that they haven't released full color images, or even raw images from which we can construct full color images. I'm really appreciating the MER rovers and their raw images..... Shame on whoever made the decision to not release anything until much later. I understand why, but it doesn't seem "universally optimal" to me.
Post by: racshot65 on 09/01/2011 07:17 pm
Quote
Sept 1, 2011
Dawn Successfully Completes Survey Orbit Phase
Dawn completed survey orbit, returning more than 2,800 pictures covering the entire illuminated surface and over three million visible and infrared spectra, exceeding the objectives for this first scientific phase of the mission.
The spectacular results will keep scientists busy (and happy!) for years. For more information on what Dawn accomplished in survey orbit, visit the September 1 Dawn Journal .
On August 31, the spacecraft resumed ion thrusting, and it will spend most of September spiraling down to the next science orbit, which is four times closer to Vesta than survey orbit.
Post by: racshot65 on 09/01/2011 07:24 pm
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_355222480.asp
Post by: ugordan on 09/01/2011 07:24 pm
really annoying that they haven't released full color images
Quite. I think in total a couple of false color images were released.
To be honest, I wouldn't be surprised if it's pretty nontrivial to get color now that we're in orbit due to Vesta's rapid rotation and Dawn orbital motion. This could require map reprojection to register color frames - most of the images released so far were simple single filter shots.
Post by: racshot65 on 09/01/2011 08:59 pm
Quote
Dawn Journal
September 1, 2011
Dear Magdawnificents,
Dawn has completed the first phase of its exploration of Vesta with tremendous success, and the peripatetic adventurer is now in powered flight again, on its way to a new location from which to scrutinize its subject. Meanwhile, scientists are deeply engaged in analyzing the magnificent views the stalwart surveyor has transmitted to Earth.
...
http://dawn.jpl.nasa.gov/mission/journal_09_01_11.asp
Post by: Chris Bergin on 09/02/2011 02:44 am
That "20km" reference brings it home.
Post by: racshot65 on 09/06/2011 04:46 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110906
Post by: racshot65 on 09/07/2011 10:39 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110907
Post by: racshot65 on 09/08/2011 07:16 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110908
Post by: racshot65 on 09/09/2011 12:54 pm
Quote
September 8, 2011
Dawn Lowering its Orbit
Dawn's spiral flight from survey orbit to its next science orbit is going very smoothly. As it continues to lower its altitude, the spacecraft begins the day today at about 1550 km (960 miles) and ends it at 1330 km (830 miles). For more on the unusual nature of Dawn's method of changing orbits, visit the February 27, 2011 Dawn Journal.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 09/09/2011 12:57 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110909
Post by: clongton on 09/09/2011 01:06 pm
Worm-like Markings on Vesta’s Surface
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110909
Any confirmation yet of chemical makeup?
Post by: ugordan on 09/09/2011 01:33 pm
Any confirmation yet of chemical makeup?
Yes, we can confirm it has chemical makeup.
Sorry, couldn't resist. ;D
Post by: clongton on 09/09/2011 03:27 pm
Any confirmation yet of chemical makeup?
Yes, we can confirm it has chemical makeup.
Sorry, couldn't resist. ;D
Aw jeeeeze :) :)
Post by: kevin-rf on 09/09/2011 05:19 pm
Any confirmation yet of chemical makeup?
Yes, we can confirm it has chemical makeup.
Sorry, couldn't resist. ;D
So when will we know what she looks like first thing in the morning?
Post by: racshot65 on 09/10/2011 02:39 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110910
Post by: racshot65 on 09/11/2011 02:45 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110911
Post by: Nomadd on 09/11/2011 11:29 pm
Post by: racshot65 on 09/12/2011 10:25 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110912
Post by: racshot65 on 09/13/2011 10:10 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110913
Post by: racshot65 on 09/14/2011 12:25 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110914
Post by: racshot65 on 09/15/2011 05:52 pm
Quote
September 15, 2011
Dawn Continues Spiraling to New Orbit
Dawn remains on course and on schedule as it uses its ion propulsion system to spiral to its next science orbit. The spacecraft begins the day today at an altitude of about 880 km (550 miles) and ends it at 790 km (490 miles).
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 09/16/2011 08:08 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110916
Post by: jacqmans on 09/16/2011 08:47 am
NASA's Dawn Collects a Bounty of Beauty from Vesta
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-293&cid=release_2011-293
PASADENA, Calif. - A new video from NASA's Dawn spacecraft takes us on a flyover journey above the surface of the giant asteroid Vesta.
The data obtained by Dawn's framing camera, used to produce the visualizations, will help scientists determine the processes that formed Vesta's striking features. It will also help Dawn mission fans all over the world visualize this mysterious world, which is the second most massive object in the main asteroid belt.
The video, which shows Vesta as seen from Dawn's perspective, can be viewed at: http://www.jpl.nasa.gov/video/index.cfm?id=1020.
You'll notice in the video that Vesta is not entirely lit up. There is no light in the high northern latitudes because, like Earth, Vesta has seasons. Currently it is northern winter on Vesta, and the northern polar region is in perpetual darkness. When we view Vesta's rotation from above the south pole, half is in darkness simply because half of Vesta is in daylight and half is in the darkness of night .
Another distinct feature seen in the video is a massive circular structure in the south pole region. Scientists were particularly eager to see this area close-up, since NASA's Hubble Space Telescope first detected it years ago. The circular structure, or depression, is several hundreds of miles, or kilometers, wide, with cliffs that are also several miles high. One impressive mountain in the center of the depression rises approximately 9 miles (15 kilometers) above the base of this depression, making it one of the highest elevations on all known bodies with solid surfaces in the solar system.
The collection of images, obtained when Dawn was about 1,700 miles (2,700 kilometers) above Vesta's surface, was used to determine its rotational axis and a system of latitude and longitude coordinates. One of the first tasks tackled by the Dawn science team was to determine the precise orientation of Vesta's rotation axis relative to the celestial sphere.
The zero-longitude, or prime meridian, of Vesta was defined by the science team using a tiny crater about 1,640 feet (500 meters) in diameter, which they named "Claudia," after a Roman woman during the second century B.C. Dawn's craters will be named after the vestal virgins-the priestesses of the goddess Vesta, and famous Roman women, while other features will be named for festivals and towns of that era.
The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Other scientific partners include Planetary Science Institute, Tucson, Ariz.; Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany; DLR Institute for Planetary Research, Berlin, Germany; Italian National Institute for Astrophysics, Rome; and the Italian Space Agency, Rome. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft.
For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .
You can also follow the mission on Twitter at: http://www.twitter.com/NASA_Dawn .
Post by: gospacex on 09/16/2011 01:09 pm
Landslides on Vesta
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110916
That's a 30 kilometer high cliff! :O
Post by: baldusi on 09/16/2011 02:33 pm
Landslides on Vesta
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110916
I keep being mesmerized by this missions. Can't they just make something like Dawn 2/3/4/5 and seriously visit the Asteroid Belt?
It also makes me think that an asteroid mission would bring tears to my eyes and renew hopes in humanity. I find this images that powerful.
Post by: ugordan on 09/16/2011 02:58 pm
I keep being mesmerized by this missions. Can't they just make something like Dawn 2/3/4/5 and seriously visit the Kuiper Belt?
No because Dawn relies on serious solar power for powering the ion propulsion. Beyond Mars it would need RTGs and those provide much fewer watts than Dawn generates.
Post by: baldusi on 09/16/2011 03:12 pm
I keep being mesmerized by this missions. Can't they just make something like Dawn 2/3/4/5 and seriously visit the Kuiper Belt?
No because Dawn relies on serious solar power for powering the ion propulsion. Beyond Mars it would need RTGs and those provide much fewer watts than Dawn generates.
My mistake, I meant Asteroid Belt. Sorry. That's why I considered that they could be made under an "asteroid pathfinder mission" umbrella. Will correct my previous post.
Post by: kevin-rf on 09/16/2011 05:14 pm
Post by: Cog_in_the_machine on 09/16/2011 05:45 pm
Post by: Blackstar on 09/16/2011 09:57 pm
There has been some study of the possibility of RTGs powering electric propulsion. I cannot remember the degree to which we studied them for the planetary decadal survey. Take a look at the mission studies:
http://sites.nationalacademies.org/SSB/SSB_059331
You might find something there. Look at the Chiron orbiter, in particular.
Something to keep in mind is that the power control system that supplies power to the ion engines is a very tricky piece of technology. As the power falls off as the spacecraft gets farther from the sun there is of course less power for the engines. That is a tough design challenge. RTGs (or ASRGs) might be easier that way. But then you have to deal with the mass issue, and RTGs are not cheap.
Post by: Robotbeat on 09/16/2011 10:11 pm
You can do solar power at Jupiter. After that, forget it. And even Jupiter is tough.Might be able to do both, actually. SEP "third stages" are listed as possibilities in a few probe proposals I've seen. Once that is developed (and if it then becomes a relatively off-the-shelf item), you could use it for your initial kick, discard it by the orbit of Jupiter (perhaps do a powered gravity assist there, using conventional thrusters), then use integrated (and lower powered) RTG-powered ion thrusters to provide propulsion near the destination, as well. You'll need to haul RTGs around anyways which will be just decaying for the most part on the way out, and the extra mission power would also be helpful once at the destination(s).
There has been some study of the possibility of RTGs powering electric propulsion. I cannot remember the degree to which we studied them for the planetary decadal survey. Take a look at the mission studies:
http://sites.nationalacademies.org/SSB/SSB_059331
You might find something there.
Something to keep in mind is that the power control system that supplies power to the ion engines is a very tricky piece of technology. As the power falls off as the spacecraft gets farther from the sun there is of course less power for the engines. That is a tough design challenge. RTGs (or ASRGs) might be easier that way. But then you have to deal with the mass issue, and RTGs are not cheap.
But unless we have both big improvements in RTG efficiency and Pu-238 production, it's unlikely we will have RTG-powered ion thrusters since missions will be very power-strapped out there if we just keep the status quo.
Post by: robertross on 09/17/2011 12:25 am
http://www.youtube.com/watch?v=MO2LFSifklE
That was a super video!
Post by: racshot65 on 09/17/2011 09:33 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110917
Post by: racshot65 on 09/19/2011 10:06 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110919
Post by: Blackstar on 09/19/2011 01:25 pm
Might be able to do both, actually. SEP "third stages" are listed as possibilities in a few probe proposals I've seen. Once that is developed (and if it then becomes a relatively off-the-shelf item), you could use it for your initial kick, discard it by the orbit of Jupiter (perhaps do a powered gravity assist there, using conventional thrusters), then use integrated (and lower powered) RTG-powered ion thrusters to provide propulsion near the destination, as well. You'll need to haul RTGs around anyways which will be just decaying for the most part on the way out, and the extra mission power would also be helpful once at the destination(s).
I got a bit of an education on this from JPL's Gentry Lee as well as a few people at GRC who work on this stuff. Gentry's main point is that SEP is a great idea if it is standardized and designers use an "off the shelf" system, but that nobody ever does that. The reality is that every time somebody proposes using SEP in a spacecraft proposal, they always call their system legacy hardware with high flight heritage (yadda yadda yadda) but it really isn't. The real killer is that power control unit, and although you could use existing ion engines, the power control unit has to be uniquely designed for the mission because the power for each mission is going to be different because of its distance from the sun, etc. The result is that the power control unit always costs a lot of money that nobody includes in their spacecraft proposal.
I imagine that a dual SEP/RTG (or Advanced Stirling Radioisotope Generator) system only makes this worse by adding two power sources.
It's not that this stuff is impossible. As Dawn demonstrates, we've gotten pretty good with solar electric propulsion. It's just that it's not as easy as you'd think to put an SEP system on various spacecraft, because it really is a system, not just a device.
As a sidenote, there are some proposals for multiple NEO asteroid rendezvous missions that use SEP. It's really the only way to visit more than one target. I've talked to somebody who worked on one and they said that they could easily get two NEOs for a single mission (like what Dawn is doing in the main belt), but three really starts to push it. That's because the orbits just don't cooperate.
Post by: Robotbeat on 09/19/2011 03:17 pm
I agree that the mass and capabilities of the power control unit are constraints that are easy to overlook (and these constraints can become just about as important as the mass of the solar arrays and thrusters themselves). Doesn't mean they couldn't be standardized in some way, though it would take effort to do so. An integrated SEP third stage hasn't been developed yet (so we can't claim that an integrated SEP stage is an existing, completely off-the-shelf capability), but it is a good idea to do it so we have this capability in the future.
Post by: Zed_Noir on 09/19/2011 04:08 pm
Also is it a good idea to use discarded solar array & SEP stage from outer system spacecrafts as communication relays after swinging by Jupiter.
Post by: Blackstar on 09/19/2011 06:52 pm
There have been proposals to do this before, but usually when they start to look at re-using older systems, too much has changed. (Glory was a good example of this that nobody is going to pay attention to because it never made orbit.)
Post by: Robotbeat on 09/19/2011 08:11 pm
The problem with standardization is that it doesn't really work when the missions are so far apart. If you develop a standardized bus or an SEP stage, you might use it once and then not again for a decade or more. By that time a lot of the subcontractors have gone out of business, technology has evolved, electronics have become obsolete, etc.That's a good point. Outer planet systems are relatively uncommon.
There have been proposals to do this before, but usually when they start to look at re-using older systems, too much has changed. (Glory was a good example of this that nobody is going to pay attention to because it never made orbit.)
Post by: Blackstar on 09/20/2011 12:11 am
That's a good point. Outer planet systems are relatively uncommon.
Unfortunately, it works for most planetary missions. There have been quite a few planetary missions in the past 15 years (I made up a list that I can post). But if you plot them out, they're all going to different places. Even the Mars missions have different requirements. It's hard to get standardization to work because the next time a similar mission opportunity comes up might be 7+ years. In addition, it's hard to get it to work when you're competing programs in Discovery and New Frontiers, because individual teams might use standardized designs, but they may lose the competition.
Standardization could work if you radically restructured the program to force it as a solution. But I don't see that happening.
Post by: Robotbeat on 09/20/2011 12:19 am
Post by: racshot65 on 09/20/2011 12:13 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110920
Post by: jacqmans on 09/21/2011 03:26 am
Public Talks Sept. 20, 2011
Journey to the Asteroid Belt with NASA Dawn Mission's Chief Engineer
Is it an asteroid or a small planet? Dr. Marc Rayman from NASA's Dawn mission exploring the giant asteroid Vesta will answer that question and more during two upcoming speaking engagements.
To Boldly Go ... Well, You Know: NASA's Dawn Mission to the Asteroid Belt
When: October 3, 2011 at 7:30 p.m.
Where: Rancho California Water District Bldg., 42125 Winchester Road, Temecula, CA
Sponsored by: Temecula Valley Astronomers Club
Note: Seating is limited
When: October 20, 2011 at 7:30 p.m.
Where: Donald E. Bianchi Planetarium at California State University, Northridge (Parking available on Zelzah Avenue)
Directions: http://www.csun.edu/aboutCSUN/directions.html
Sponsored by: CSUN Physics and Astronomy Department
Learn more at: http://www.csun.edu/phys/department_guide/colloquia_and_planetarium/planetarium.html
Overview: Join Dr. Marc Rayman, the chief engineer for NASA's Dawn mission, which is exploring the giant asteroid Vesta, for a public talk about Dawn, its use of ion propulsion and its two exotic asteroid belt destinations. And share in the excitement of controlling a spacecraft on a revolutionary journey through space.
The ambitious and exciting Dawn mission is one of NASA's most remarkable ventures into the solar system. Dawn arrived at its first target, the giant asteroid Vesta, in July and has already sent back stunning imagery and fascinating data. And in just a year, it'll begin its journey to a second body in the asteroid belt called Ceres, which is so large that it's included in the category of dwarf planets, along with Pluto. Both are the most massive residents of the asteroid belt and among the last uncharted worlds in the inner solar system.
Dawn, the only spacecraft ever to orbit an object in the asteroid belt and the first ever designed to orbit two solar system bodies, will study these alien landscapes to uncover clues about the evolution and history of the solar system. Such a mission would be impossible without the use of ion propulsion, a technology that has mostly existed in the domain of science fiction, but which was tested extensively on NASA's Deep Space 1 mission, paving the way for Dawn.
-end-
Post by: racshot65 on 09/21/2011 11:11 am
Quote
September 20, 2011
Dawn Nearly in New Science Orbit
On Sept. 18, Dawn successfully completed the majority of the planned ion thrusting needed to reach its new science orbit, the high altitude mapping orbit.
Now navigators are measuring its orbital parameters precisely so they can design a final maneuver to ensure the spacecraft is in just the orbit needed to begin its intensive mapping observations next week.
(An explanation of why the orbit needs adjustment can be found in the February 27, 2011 Dawn Journal.)
Dawn is orbiting at an altitude of about 680 kilometers (420 miles).
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 09/21/2011 11:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110921
Post by: racshot65 on 09/22/2011 01:25 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110922
Post by: racshot65 on 09/23/2011 10:00 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110923
Post by: racshot65 on 09/26/2011 07:54 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?
date=20110926
Post by: racshot65 on 09/27/2011 09:42 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110927
Post by: Robotbeat on 09/27/2011 10:01 pm
Closing in on the Wrinkles and Grooves at Vesta’s South PoleLink was broken. Here it is fixed:
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?
date=20110926
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110926 (http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110926)
Post by: racshot65 on 09/28/2011 03:47 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110928 (http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110928)
Post by: racshot65 on 09/29/2011 03:28 pm
Quote
September 26, 2011
Dawn Ready for Final Orbit Adjustment
Controllers have designed a pair of maneuvers with the ion propulsion system to adjust Dawn's orbit around Vesta to match it to the conditions needed for the planned observations in its new high altitude mapping orbit (HAMO). The first maneuver will be performed tonight and the second will be the next night.
The operations team has taken advantage of the period between the end of thrusting on Sept. 18 and the beginning of intensive science observations in HAMO to perform other activities.
They have conducted bonus science measurements with all the instruments. In addition, they used the backup science camera to verify that it continues to be healthy. They have also performed further tests with the visible and infrared mapping spectrometer.
On Sept. 21, when the spacecraft was reconfiguring its memory in preparation for collecting science data in HAMO, a software function took longer than expected and caused the computer to reboot. As a result, Dawn entered safe mode.
Controllers detected the condition that night, diagnosed the cause, and returned the spacecraft to its normal operating condition less than two days later.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 09/29/2011 03:29 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110929
Post by: racshot65 on 09/30/2011 04:22 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20110930
Post by: jacqmans on 09/30/2011 10:00 pm
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-307&cid=release_2011-307
PASADENA, Calif. -- NASA's Dawn spacecraft has completed a gentle spiral into its new science orbit for an even closer view of the giant asteroid Vesta. Dawn began sending science data on Sept. 29 from this new orbit, known as the high altitude mapping orbit (HAMO).
In this orbit, the average distance from the spacecraft to the Vesta surface is 420 miles (680 kilometers), which is four times closer than the previous survey orbit. The spacecraft will operate in the same basic manner as it did in the survey orbit. When Dawn is over Vesta's dayside, it will point its science instruments to the giant asteroid and acquire data, and when the spacecraft flies over the nightside, it will beam that data back to Earth.
Perhaps the most notable difference in the new orbit is the frequency with which Dawn circles Vesta. In survey orbit, it took Dawn three days to make its way around the asteroid. Now in HAMO, the spacecraft completes the same task in a little over 12 hours. HAMO is scheduled to last about 30 Earth days, during which Dawn will circle Vesta more than 60 times. For about 10 of those 30 days, Dawn will peer straight down at the exotic landscape below it during the dayside passages. For about 20 days, the spacecraft will view the surface at multiple angles.
Scientists will combine the pictures to create topographic maps, revealing the heights of mountains, the depths of craters and the slopes of plains. This will help scientists understand the geological processes that shaped Vesta.
HAMO, the most complex and intensive science campaign at Vesta, has three primary goals: to map Vesta's illuminated surface in color, provide stereo data, and acquire visible and infrared mapping spectrometer data. In addition, it will allow improved measurements of Vesta's gravity.
Dawn launched in September 2007 and arrived at Vesta in July 2011. Since beginning its first survey orbit in August, Dawn has been extensively imaging this intriguing world, sending back a bounty of images and other data. NASA-funded scientists and European scientists on the Dawn mission team will present a wealth of new findings at the joint meeting of the American Astronomical Society's Division for Planetary Sciences and the European Planetary Science Congress next week at La Cite Internationale des Congres Nantes Metropole, Nantes, France.
These findings about the giant asteroid Vesta will include information about the new coordinate system and official names of Vesta's prominent features.
A Dawn mission news conference will be held Monday, Oct. 3, 2011 at 12:15 p.m. CEST (3:15 a.m. PDT/6:15 a.m. EDT). The Division for Planetary Sciences will provide live Web streaming of this news conference, at:
http://meetings.copernicus.org/epsc-dps2011/webstreaming/monday.html
"The team has been in awe of what they have seen on the surface of Vesta," said Christopher Russell, Dawn principal investigator, at UCLA. "We are sharing those discoveries with the greater scientific community and with the public."
Following a year at Vesta, the spacecraft will depart in July 2012 for Ceres, where it will arrive in 2015. Dawn's mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
The image and more information about the Dawn mission are online at: http://www.nasa.gov/dawn . To follow the mission on Twitter, visit: http://www.twitter.com/NASA_Dawn
Post by: racshot65 on 10/01/2011 02:45 pm
Quote
September 29, 2011
Dawn Begins New Science Campaign
Dawn began its new phase of Vesta observations today. Circling Vesta every 12.3 hours at an average altitude of 680 kilometers (420 miles), it will take pictures and acquire visible and infrared spectra when it passes over the day side and transmit the data to Earth while over the night side. This intensive phase of the mission will last about a month. Additional details on this high altitude mapping orbit are in the September 27, 2010 Dawn Journal.
The maneuvers to adjust the orbit earlier this week were executed very smoothly. In between them, on Sept. 27, Dawn celebrated is fourth anniversary of being in space. Additional anniversary details are in the Dawn Journal for September 27, 2011.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 10/01/2011 02:46 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111001
Post by: racshot65 on 10/03/2011 08:51 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111002
Post by: racshot65 on 10/03/2011 08:51 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111003
Post by: kevin-rf on 10/04/2011 05:43 pm
Does anyone know where the original is on the Dawn site?
Post by: Hungry4info3 on 10/04/2011 06:43 pm
link (http://www.europlanet-eu.org/outreach/index.php?option=com_content&task=view&id=352&Itemid=41).
Post by: kevin-rf on 10/04/2011 06:47 pm
Post by: racshot65 on 10/04/2011 07:19 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111004
Post by: Moe Grills on 10/04/2011 08:08 pm
In a newspaper I read today, it says that scientists have
confirmed that there is a mountain taller than Everest on the asteroid Vesta.
Where is it, as far as latitude/longitude is concerned?
And where is the imagery for that mountain?
Post by: hop on 10/04/2011 08:55 pm
Where is it, as far as latitude/longitude is concerned?It's the central mound of the south pole crater.
Quote
And where is the imagery for that mountain?Some examples:
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_071811.asp
http://dawn.jpl.nasa.gov/multimedia/dawn_vesta_image_PIA14711.asp
Post by: racshot65 on 10/05/2011 02:49 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111005
Post by: racshot65 on 10/06/2011 05:04 pm
Quote
October 5, 2011
First Mapping Cycle Completed
Dawn's mapping of Vesta from an altitude of about 680 kilometers (420 miles) is going very smoothly. It has completed its first cycle of 10 orbits in which the principal objective was to acquire images looking straight down.
Today the spacecraft will begin a new cycle of observing the surface at an angle to provide images scientists will use to create topographic maps and stereo images. This mapping strategy is described in more detail in the September 27, 2010 Dawn Journal.
Scientists and engineers are investigating increased noise in one of the gamma-ray sensors in the gamma-ray and neutron detector (GRaND).
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 10/06/2011 05:04 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111006
Post by: racshot65 on 10/07/2011 03:15 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111007
Post by: racshot65 on 10/08/2011 04:34 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111008
Post by: racshot65 on 10/09/2011 03:12 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111009
Post by: racshot65 on 10/10/2011 07:47 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111010
Post by: jacqmans on 10/11/2011 07:32 am
New View of Vesta Mountain From NASA's Dawn Mission
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-317&cid=release_2011-317
A new image from NASA's Dawn spacecraft shows a mountain three times as high as Mt. Everest, amidst the topography in the south polar region of the giant asteroid Vesta.
The peak of Vesta's south pole mountain, seen in the center of the image, rises about 13 miles (22 kilometers) above the average height of the surrounding terrain. Another impressive structure is a large scarp, a cliff with a steep slope, on the right side of this image. The scarp bounds part of the south polar depression, and the Dawn team's scientists believe features around its base are probably the result of landslides.
The image is online at: http://www.nasa.gov/mission_pages/dawn/multimedia/pia14869.html . It was created from a shape model of Vesta, and shows an oblique perspective view of the topography of the south polar region. The image resolution is about 300 meters per pixel, and the vertical scale is 1.5 times that of the horizontal scale.
Dawn entered orbit around Vesta in July. Members of the mission team will discuss what the spacecraft has seen so far during a news conference at the Annual Meeting of the Geological Society of America in Minneapolis. Among other things, they'll share their hypotheses on the origins of Vesta's curious craters.
The meeting, at the Minneapolis Convention Center, runs from Oct. 9 to 12, with the Dawn news conference scheduled for Wednesday, Oct. 12, at 10 a.m. PDT (noon CDT).
The event will air live on the Geological Society of America webcast page at:
http://hosted.mediasite.com/mediasite/Viewer/?peid=e8adbee5a37e455fbe199b29129e3b7c1d . Media representatives not able to attend the meeting may participate by registering at: http://rock.geosociety.org/forms/11_pressConf.asp . More information about the webcast is at:
http://www.geosociety.org/news/pr/11-63.htm .
The event will also be carried live, with a moderated chat, at: http://www.ustream.tv/nasajpl2 .
The news conference panelists are:
Carol Raymond, Dawn deputy principal investigator, NASA's Jet Propulsion Laboratory, Pasadena, Calif.
Paul Schenk, Dawn participating scientist, Lunar and Planetary Institute, Houston
Debra Buczkowski, Dawn participating scientist, Applied Physics Laboratory, Johns Hopkins University, Laurel, Md.
Federico Tosi, Dawn Visible and Infrared Spectrometer team member, Italian Space Agency, Rome
Following a year at Vesta, the spacecraft will depart in July 2012 for Ceres, where it will arrive in 2015. Dawn's mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
More information about the Dawn mission is at: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov . To follow the mission on Twitter, visit: http://www.twitter.com/NASA_Dawn .
Post by: racshot65 on 10/11/2011 03:07 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111011
Post by: Bubbinski on 10/12/2011 04:50 am
That scarp is also impressive. Would love to see rovers or better yet astronauts gazing up at that thing sometime.
Post by: Comga on 10/12/2011 05:05 am
Thanks for the pics Aaron. That mountain is about 68,000 feet tall, wonder what caused it to get so high. .....
Central peaks in craters usually a reflex action. Check out the Ring-Peak Craters (http://www.uwgb.edu/dutchs/planets/cratform.htm) description. "In some large craters... the rising central peak actually overshoots its stable height."
Post by: racshot65 on 10/12/2011 01:44 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111012
Post by: jacqmans on 10/12/2011 07:25 pm
NASA's Dawn Science Team Presents Early Science Results
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-319&cid=release_2011-319
Scientists with NASA's Dawn mission are sharing with other scientists and the public their early information about the southern hemisphere of the giant asteroid Vesta. The findings were presented today at the annual meeting of the Geological Society of America in Minneapolis, Minn.
Dawn, which has been orbiting Vesta since mid-July, has found that the asteroid's southern hemisphere boasts one of the largest mountains in the solar system. Other findings show that Vesta's surface, viewed by Dawn at different wavelengths, has striking diversity in its composition, particularly around craters. Science findings also include an in-depth analysis of a set of equatorial troughs on Vesta and a closer look at the object's intriguing craters. The surface appears to be much rougher than most asteroids in the main asteroid belt. In addition, preliminary dates from a method that uses the number of craters indicate that areas in the southern hemisphere are as young as 1 billion to 2 billion years old, much younger than areas in the north.
Scientists do not yet understand how all the features on Vesta's surface formed, but they did announce today, after analysis of northern and southern troughs, that results are consistent with models of fracture formation due to giant impact.
Since July, the Dawn spacecraft has been spiraling closer and closer to Vesta, moving in to get better and better views of the surface. In early August, the spacecraft reached an orbital altitude of 1,700 miles (2,700 kilometers) and mapped most of the sunlit surface, during survey orbit, with its framing camera and visible and infrared mapping spectrometer.
That phase was completed in late August, and the spacecraft began moving in to what is known as High Altitude Mapping Orbit at about 420 miles (680 kilometers) above Vesta, which it reached on Sept. 29.
An archive of the live news conference is available for viewing at: http://www.ustream.tv/nasajpl2 .
The Dawn scientists also shared their findings at the recent European Planetary Science Congress and the Division of Planetary Sciences Joint Meeting 2011 in Nantes, France.
Dawn launched in September 2007 and arrived at Vesta on July 15, 2011. Following a year at Vesta, the spacecraft will depart in July 2012 for the dwarf planet Ceres, where it will arrive in 2015.
Dawn's mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
For more information about the Dawn mission, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov . To follow the mission on Twitter, visit: http://www.twitter.com/NASA_Dawn .
Post by: racshot65 on 10/13/2011 02:51 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111013
Post by: racshot65 on 10/14/2011 05:27 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111014
Post by: racshot65 on 10/15/2011 10:18 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111015
Post by: racshot65 on 10/16/2011 08:57 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111016
Post by: racshot65 on 10/17/2011 07:41 pm
Quote
October 16, 2011
Dawn Reaches Halfway Point in HAMO Mapping
Dawn has completed its third mapping cycle in the high altitude mapping orbit (HAMO).
Now it is beginning the fourth cycle, in which the spacecraft points its camera ahead at a different angle from the second cycle. The images from the different viewing angles will be combined to create topographic maps.
Observations with the visible and infrared mapping spectrometer and the gamma-ray and neutron spectrometer continue as well.
The mapping cycles are conducted in the order of their importance, so the most valuable measurements in HAMO have now been completed successfully.
Post by: racshot65 on 10/17/2011 07:42 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111017
Post by: racshot65 on 10/18/2011 04:27 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111018
Post by: racshot65 on 10/19/2011 01:28 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111019
Post by: racshot65 on 10/20/2011 07:34 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111020
Post by: racshot65 on 10/21/2011 05:14 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111021
Post by: racshot65 on 10/22/2011 09:41 am
Quote
October 21, 2011
Dawn Completes More Topographical Mapping
With its fourth mapping cycle complete, today Dawn began its fifth mapping cycle. This is the last one devoted to acquiring images for topography. The camera will mostly be pointed to the side as the spacecraft orbits Vesta.
Post by: racshot65 on 10/22/2011 09:41 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111022
Post by: racshot65 on 10/23/2011 09:00 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111023
Post by: racshot65 on 10/24/2011 04:23 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111024
Post by: racshot65 on 10/25/2011 03:28 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111025
Post by: clongton on 10/25/2011 08:01 pm
Post by: racshot65 on 10/25/2011 08:15 pm
Quote
... The right image is also a RGB composite image. This time red is the ratio of the brightness at a wavelength of 750nm to the brightness at 440nm; green is used for the ratio of the brightness at 750nm to 920nm and blue is used for the ratio of the brightness at 440nm to 750nm. These ratios have all been picked for specific scientific purposes. The green shows the relative strengh of a particular mineralogical characteristic, the ferrous absorption band, at 1000nm so that a brighter green color signifies a higher relative strength of this band. The blending between the red and blue heightens the color range of visible light...
Post by: clongton on 10/25/2011 09:05 pm
Even though you do 95% of all the posting on this thread I want you to know that there are lots of people reading what you write and examining what you provide.
Thank you.
Post by: racshot65 on 10/27/2011 03:33 pm
Quote
Dawn Concludes Topographical Mapping
Today Dawn successfully concluded its fifth mapping cycle and the final one devoted to topographical mapping. It is now beginning the last mapping cycle of the high altitude mapping orbit. This sixth cycle is nearly identical to the first and was included in the plan in case there were problems with the the first. As it was successful, most of these observations will provide views very similar to the ones already returned.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 10/27/2011 03:34 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111027
Post by: racshot65 on 10/28/2011 08:18 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111028
Post by: racshot65 on 10/29/2011 09:32 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111029
Post by: racshot65 on 10/30/2011 09:01 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111030
Post by: racshot65 on 10/31/2011 02:30 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111031
Post by: racshot65 on 11/01/2011 04:43 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111101
Post by: racshot65 on 11/02/2011 02:50 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111102
Post by: racshot65 on 11/03/2011 11:51 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111103
Post by: racshot65 on 11/04/2011 09:15 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111104
Post by: racshot65 on 11/04/2011 09:16 am
Quote
November 2, 2011
Dawn Concludes Intensive Mapping
On October 31, Dawn completed the sixth and final mapping cycle. It spent another two days transmitting to Earth the last of the science data it had gathered. The successful completion of this mapping marks an extraordinary milestone in the exploration of Vesta. More information about this remarkable phase of the mission is in the October 31 Dawn Journal.
Today Dawn began thrusting with its ion propulsion system. It will take more than five weeks of maneuvering to reach the next science orbit.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 11/05/2011 12:09 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111105
Post by: racshot65 on 11/06/2011 09:16 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111106
Post by: racshot65 on 11/07/2011 08:29 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111107
Post by: racshot65 on 11/08/2011 03:24 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111108
Post by: racshot65 on 11/09/2011 08:34 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111109
Post by: racshot65 on 11/16/2011 08:21 pm
Quote
November 10, 2011
Dawn Lowering Orbital Altitude
Dawn is using its ion propulsion system to lower its orbital altitude. Today the spacecraft is at an altitude of about 400 kilometers (250 miles).
On November 7 thrusting was halted for the spacecraft to collect some images of Vesta.
Post by: racshot65 on 11/16/2011 08:22 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111116
Post by: racshot65 on 11/18/2011 09:28 am
Quote
November 17, 2011
Dawn Thrusting to a Lower Orbit
Dawn has been continuing to change its orbit with its ion propulsion system. Today the spacecraft reaches down to an altitude of about 265 kilometers (165 miles). While more ion thrusting lies ahead to reduce the altitude, the craft will spend most of the time before its next science phase begins on December 12 using Vesta's gravity to change the orientation of its orbit. (The target altitude and orientation and the method of achieving them will be explained in the next Dawn Journal.)
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 11/18/2011 09:33 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111118
Post by: racshot65 on 11/19/2011 09:46 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111119
Post by: racshot65 on 11/20/2011 09:23 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111120
Post by: racshot65 on 11/21/2011 08:19 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111121
Post by: racshot65 on 11/22/2011 09:13 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111122
Post by: racshot65 on 11/23/2011 08:10 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111123
Post by: racshot65 on 11/23/2011 06:17 pm
Quote
November 23, 2011
Dawn Progressing to New Orbit
Dawn is continuing to make good progress toward its next planned orbit. The spacecraft thrusts occasionally with its ion propulsion system, but most of the time it coasts, letting Vesta's gravity reorient its orbit.
The spacecraft acquired some images of Vesta on November 20 and 23.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 11/24/2011 07:58 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111124
Post by: racshot65 on 11/25/2011 09:31 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111125
Post by: racshot65 on 11/26/2011 11:47 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111126
Post by: racshot65 on 11/27/2011 08:51 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111127
Post by: racshot65 on 11/28/2011 08:48 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111128
Post by: MATTBLAK on 11/28/2011 09:05 am
Post by: Jason1701 on 11/28/2011 04:27 pm
Makes me want to go explore it, or at least watch others do so! What's the surface gravity of Vesta? Minimal I bet - a human probably couldn't actually walk there. And what about the delta-vee requirements for landing either a Rover or "hopper" probe there?
Gravity is 1/45th g, so no walking. Ceres is not much more.
Post by: racshot65 on 11/29/2011 07:55 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111129
Post by: racshot65 on 11/30/2011 08:31 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111130
Post by: racshot65 on 12/01/2011 07:53 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111201
Post by: racshot65 on 12/01/2011 04:50 pm
http://dawn.jpl.nasa.gov/mission/journal_11_29_11.asp
Post by: racshot65 on 12/02/2011 07:56 am
http://www.jpl.nasa.gov/news/news.cfm?release=2011-366
Post by: racshot65 on 12/02/2011 08:05 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111202
Post by: racshot65 on 12/03/2011 10:06 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111203
Post by: racshot65 on 12/04/2011 08:47 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111204
Post by: racshot65 on 12/07/2011 08:32 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111207
Post by: racshot65 on 12/07/2011 01:19 pm
http://dawn.jpl.nasa.gov/feature_stories/vesta_color_palette.asp
Post by: racshot65 on 12/08/2011 07:35 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111208
Post by: racshot65 on 12/09/2011 09:31 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111209
Post by: racshot65 on 12/10/2011 09:52 am
Quote
December 8, 2011
Dawn Reaches Planned Orbit Altitude
Dawn has reached its target altitude, averaging 210 kilometers (130 miles) above Vesta.
On Dec. 3, while the spacecraft was turning in preparation for a final brief period of ion thrusting to refine its orbit, protective software detected a discrepancy in the orientation and put the spacecraft into safe mode. The discrepancy was a result of the spacecraft computing and then using a turn rate that was slightly too high. The operations team quickly established that the spacecraft was healthy, and on Dec. 5 they commanded it out of safe mode.
Mission planners already had several more windows planned for ion thrusting in order to make further fine adjustments to the orbit. Lengthening one of those windows allows sufficient time to compensate for the safe mode.
Science observations in the new orbit are scheduled to begin on Dec. 12.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 12/10/2011 09:53 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111210
Post by: racshot65 on 12/11/2011 09:00 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111211
Post by: racshot65 on 12/12/2011 09:17 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111212
Post by: yg1968 on 12/13/2011 03:20 am
http://www.youtube.com/watch?v=_JBNkts5YXA
Post by: racshot65 on 12/13/2011 08:54 am
http://www.jpl.nasa.gov/news/news.cfm?release=2011-384
Post by: racshot65 on 12/13/2011 08:58 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20111213
Post by: Robotbeat on 12/13/2011 02:52 pm
Vesta: asteroid or dwarf planet?Thanks. :)
http://www.youtube.com/watch?v=_JBNkts5YXA
Post by: robertross on 12/14/2011 01:56 am
Vesta: asteroid or dwarf planet?Thanks. :)
Very cool.
I vote dwarf planet!
:)
(picturing a mining operation on there one day for the potential of nickel & iron)
Post by: racshot65 on 12/14/2011 02:59 pm
Quote
December 13, 2011
Dawn Begins New Science Phase at Lowest Altitude
Dawn began a new set of science observations on schedule on Dec. 12 in its low altitude mapping orbit (LAMO) at an average altitude of 210 kilometers (130 miles). This phase will be the longest of the science campaigns at Vesta, lasting at least 10 weeks.
Dawn's investigations in this orbit will focus on measuring the elemental composition of the surface and subsurface material with the gamma ray and neutron detector and on mapping the interior structure by measuring Vesta's gravity field. In addition, the science camera and the visible and infrared mapping spectrometer will be used for some bonus observations. An overview of the plan for LAMO is in the Dawn Journal from Dec. 30, 2010, and further details will be in upcoming Dawn Journals.
The Dawn "image of the day" will take a break until Jan. 9. When it returns, there will be more spectacular views of this exotic world.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 12/21/2011 03:28 pm
http://www.jpl.nasa.gov/news/news.cfm?release=2011-391&cid=release_2011-391&msource=11391&tr=y&auid=10053953#1
Post by: racshot65 on 12/23/2011 09:51 am
Quote
December 21, 2011
Dawn Continues Gathering Science Data
Dawn is continuing to gather gamma ray spectra and neutron spectra in its low altitude orbit. In addition, scientists and engineers are making accurate measurements of the spacecraft's orbit to determine Vesta's gravity field.
The bonus imaging is yielding pictures more than three times better than those acquired in the high altitude mapping orbit.
Every week at this low altitude, Dawn will use its ion propulsion system to fine tune its orbit. (The reasons for this will be explained in an upcoming Dawn Journal.) The first of these weekly orbit adjustments was performed on December 17.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 12/30/2011 10:14 am
Quote
December 29, 2011
Dawn Observations in Low Altitude Orbit Continue Smoothly
Dawn spends most of its time measuring gamma rays and neutrons from Vesta so scientists can determine the abundances of elements in the material near the surface. The team is continuing to track the spacecraft in order to map Vesta's gravity field. Taking advantage of the low altitude, the imaging campaign continues to reveal new details of the surface.
The spacecraft performed another small adjustment to its orbit on December 24. These last two maneuvers were performed so accurately and the actual orbit is matching the predictions so well that the next two weekly adjustments have been canceled.
As the activities in the low altitude mapping orbit are intended to be highly repetitive, these mission status updates will be less frequent (thus saving your correspondent the effort of finding ways to restate what he wrote last week and this week). Updates will continue to be posted when events warrant and occasionally to reassure readers that the mission is continuing smoothly. More information about Dawn's work in this phase of the mission can be found in the Dawn Journals.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 12/31/2011 07:24 pm
http://science.nasa.gov/science-news/science-at-nasa/2011/30dec_spacemountain/
Post by: racshot65 on 01/05/2012 08:45 pm
http://dawn.jpl.nasa.gov/mission/journal_12_30_11.asp
Post by: racshot65 on 01/09/2012 08:56 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120109
Post by: racshot65 on 01/10/2012 01:13 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120110
Post by: racshot65 on 01/11/2012 02:29 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120111
Post by: racshot65 on 01/12/2012 09:26 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120112
Post by: racshot65 on 01/13/2012 05:20 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120113
Post by: racshot65 on 01/16/2012 06:21 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120116
Post by: racshot65 on 01/17/2012 08:49 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120117
Post by: racshot65 on 01/18/2012 07:28 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120118
Post by: racshot65 on 01/19/2012 10:44 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120119
Post by: racshot65 on 01/20/2012 05:51 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120120
Post by: racshot65 on 01/23/2012 05:31 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120123
Post by: racshot65 on 01/24/2012 09:17 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120124
Post by: racshot65 on 01/25/2012 12:05 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120125
Post by: racshot65 on 01/26/2012 08:31 am
http://dawn.jpl.nasa.gov/feature_stories/cold_dark_vesta.asp
Post by: racshot65 on 01/26/2012 08:36 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120126
Post by: racshot65 on 01/27/2012 07:36 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120127
Post by: racshot65 on 01/28/2012 11:59 am
http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=738
Post by: racshot65 on 01/28/2012 12:00 pm
Quote
January 27, 2012
Low Altitude Mapping of Vesta Proceeding Well
Dawn is in good health and using all of its sensors to make detailed measurements of Vesta, following the pattern it has used from the beginning of the low altitude mapping campaign.
On January 13, a software bug caused the main computer to reboot and Dawn entered safe mode. The operations team soon detected the spacecraft's condition. They subsequently returned the probe to the correct configuration and resumed normal operations. Engineers understand how to avoid triggering this bug again.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 01/28/2012 12:07 pm
http://dawn.jpl.nasa.gov/mission/journal_01_27_12.asp
These are really good, well worth the long read.
Post by: racshot65 on 01/30/2012 05:27 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120130
Post by: racshot65 on 01/31/2012 09:04 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120131
Post by: racshot65 on 02/01/2012 08:43 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120201
Post by: racshot65 on 02/02/2012 09:38 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120202
Post by: racshot65 on 02/03/2012 09:39 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120203
Post by: racshot65 on 02/06/2012 08:07 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120206
Post by: racshot65 on 02/07/2012 08:37 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120207
Post by: racshot65 on 02/08/2012 10:36 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120208
Post by: racshot65 on 02/09/2012 08:30 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120209
Post by: racshot65 on 02/10/2012 09:22 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120210
Post by: racshot65 on 02/13/2012 05:16 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120213
Post by: racshot65 on 02/14/2012 09:02 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120214
Post by: racshot65 on 02/15/2012 03:14 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120215
Post by: racshot65 on 02/16/2012 08:24 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120216
Post by: racshot65 on 02/17/2012 06:56 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120217
Post by: racshot65 on 02/20/2012 11:39 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120220
Post by: racshot65 on 02/21/2012 08:50 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120221
Post by: racshot65 on 02/22/2012 08:06 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120222
Post by: racshot65 on 02/23/2012 07:41 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120223
Post by: racshot65 on 02/24/2012 10:41 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120224
Post by: clongton on 02/24/2012 12:04 pm
What is the surface gravity gradient?
Post by: racshot65 on 02/27/2012 04:15 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120227
Post by: racshot65 on 02/28/2012 09:00 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120228
Post by: racshot65 on 02/29/2012 12:50 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120229
Post by: racshot65 on 02/29/2012 08:09 pm
I wasn't, but I started and here it is:
https://docs.google.com/spreadsheet/ccc?key=0AtgDSxr4VJxudGV3V2p1LVctT0djbC1CQ0lVdFFSMGc
Post by: clongton on 02/29/2012 10:45 pm
A few weeks ago clongton asked if I was keeping a record of global locational data for all these photos.
I wasn't, but I started and here it is:
https://docs.google.com/spreadsheet/ccc?key=0AtgDSxr4VJxudGV3V2p1LVctT0djbC1CQ0lVdFFSMGc
THANK YOU!!!
Post by: racshot65 on 03/01/2012 08:22 am
Quote
February 29, 2012
Dawn Continuing to Scrutinize Vesta from Low Altitude
Dawn has maintained its intensive pace of collecting data on Vesta. While priority remains on measuring the composition of the surface and mapping the gravity field, all scientific instruments are being used to study the protoplanet from an average distance of 210 kilometers (130 miles). The latest Dawn Journal describes the variations in altitude as Dawn loops around Vesta.
The plan for Dawn's year at Vesta had the spacecraft spending 70 days in the low altitude mapping orbit. As explained in the January and February Dawn Journals, operations at Vesta have gone so well that the 40 days held as margin to resolve problems are still available. Therefore, they are being applied to extend this phase of the exploration of Vesta. Dawn's measurements are now going beyond what had been anticipated.
On February 21, the spacecraft's main computer was temporarily overloaded with tasks, so it rebooted and the spacecraft entered safe mode. Operators responded quickly and had Dawn back to its normal operational configuration in less than three days.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 03/01/2012 08:25 am
http://dawn.jpl.nasa.gov/mission/journal_02_29_12.asp
Post by: racshot65 on 03/01/2012 08:29 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120301
Post by: racshot65 on 03/02/2012 12:58 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120302
Post by: Martin FL on 03/02/2012 02:26 pm
Post by: racshot65 on 03/05/2012 01:26 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120305
Post by: racshot65 on 03/06/2012 08:59 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120306
Post by: racshot65 on 03/07/2012 12:52 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120307
Post by: racshot65 on 03/08/2012 08:43 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120308
Post by: racshot65 on 03/09/2012 02:24 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120309
Post by: racshot65 on 03/12/2012 08:02 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120312
Post by: racshot65 on 03/13/2012 08:56 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120313
Post by: racshot65 on 03/14/2012 01:57 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120314
Post by: racshot65 on 03/15/2012 09:41 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120315
Post by: racshot65 on 03/16/2012 09:16 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120316
Post by: racshot65 on 03/19/2012 08:57 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120319
Post by: racshot65 on 03/20/2012 09:34 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120320
Post by: racshot65 on 03/21/2012 10:34 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120321
Post by: jacqmans on 03/21/2012 06:24 pm
NASA'S DAWN SEES NEW SURFACE FEATURES ON GIANT ASTEROID VESTA
WASHINGTON -- NASA's Dawn spacecraft has revealed unexpected details
on the surface of the giant asteroid Vesta. New images and data
highlight the diversity of Vesta's surface and reveal unusual
geologic features, some of which were never previously seen on
asteroids.
Vesta is one of the brightest objects in the solar system and the only
asteroid in the so-called main belt between Mars and Jupiter visible
to the naked eye from Earth. Dawn found that some areas on Vesta can
be nearly twice as bright as others, revealing clues about the
asteroid's history.
"Our analysis finds this bright material originates from Vesta and has
undergone little change since the formation of Vesta over 4 billion
years ago," said Jian-Yang Li, a Dawn participating scientist at the
University of Maryland, College Park. "We're eager to learn more
about what minerals make up this material and how the present Vesta
surface came to be."
Bright areas appear everywhere on Vesta but are most predominant in
and around craters. The areas vary from several hundred feet to
around 10 miles across. Rocks crashing into the surface of Vesta seem
to have exposed and spread this bright material. This impact process
may have mixed the bright material with darker surface material.
While scientists had seen some brightness variations in previous
images of Vesta from NASA's Hubble Space Telescope, Dawn scientists
also did not expect such a wide variety of distinct dark deposits
across its surface. The dark materials on Vesta can appear dark gray,
brown and red. They sometimes appear as small, well-defined deposits
around impact craters. They also can appear as larger regional
deposits, like those surrounding the impact craters scientists have
nicknamed the "snowman."
"One of the surprises was the dark material is not randomly
distributed," said David Williams, a Dawn participating scientist at
Arizona State University, Tempe. "This suggests underlying geology
determines where it occurs."
The dark materials seem to be related to impacts and their aftermath.
Scientists theorize carbon-rich asteroids could have hit Vesta at
speeds low enough to produce some of the smaller deposits without
blasting away the surface.
Higher-speed asteroids also could have hit the asteroid's surface and
melted the volcanic basaltic crust, darkening existing surface
material. That melted conglomeration appears in the walls and floors
of impact craters, on hills and ridges, and underneath brighter, more
recent material called ejecta, which is material thrown out from a
space rock impact.
Vesta's dark materials suggest the giant asteroid may preserve ancient
materials from the asteroid belt and beyond, possibly from the birth
of the solar system.
"Some of these past collisions were so intense they melted the
surface," said Brett Denevi, a Dawn participating scientist at the
Johns Hopkins University Applied Physics Laboratory in Laurel, Md.
"Dawn's ability to image the melt marks a unique find. Melting events
like these were suspected, but never before seen on an asteroid."
Dawn launched in September 2007. It will reach its second destination,
Ceres, in February 2015.
"Dawn's ambitious exploration of Vesta has been going beautifully,"
said Marc Rayman, Dawn chief engineer at NASA's Jet Propulsion
Laboratory (JPL) in Pasadena, Calif. "As we continue to gather a
bounty of data, it is thrilling to reveal fascinating alien
landscapes."
Dawn's mission is managed by JPL for NASA's Science Mission
Directorate in Washington. Dawn is a project of the directorate's
Discovery Program, managed by NASA's Marshall Space Flight Center in
Huntsville, Ala. UCLA is responsible for overall Dawn mission
science. Orbital Sciences Corp. in Dulles, Va., designed and built
the spacecraft. The German Aerospace Center, the Max Planck Institute
for Solar System Research, the Italian Space Agency and the Italian
National Astrophysical Institute are international partners on the
mission team.
To view the new images, visit:
http://www.nasa.gov/dawn
Post by: racshot65 on 03/22/2012 10:42 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120321
Post by: racshot65 on 03/23/2012 05:49 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120323
Post by: racshot65 on 03/26/2012 10:06 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120326
Post by: racshot65 on 03/27/2012 09:39 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120327
Post by: racshot65 on 03/28/2012 10:32 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120328
Post by: racshot65 on 03/29/2012 12:30 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120329
Post by: racshot65 on 03/30/2012 10:19 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120330
Post by: racshot65 on 03/30/2012 10:19 am
http://dawn.jpl.nasa.gov/mission/journal_03_29_12.asp
Post by: clongton on 03/31/2012 12:33 am
Post by: racshot65 on 03/31/2012 04:16 pm
Quote
March 29, 2012 - Dawn's Investigations of Vesta Continue
Dawn has had another very productive month of using all sensors to investigate Vesta.
The spacecraft is operating very smoothly in its low-altitude mapping orbit.
Meanwhile, as Earth and Dawn follow their separate orbits around the sun, the probe is now on the opposite side of the sun from Earth. As explained in the most recent Dawn Journal, you can find the ship's approximate location by using the sun as a reference. Only a few probes have ever operated so far from home.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 04/02/2012 10:37 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120402
Post by: racshot65 on 04/03/2012 10:47 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120403
Post by: racshot65 on 04/04/2012 02:12 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120404
Post by: racshot65 on 04/05/2012 12:38 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120405
Post by: racshot65 on 04/06/2012 01:19 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120406
Post by: racshot65 on 04/09/2012 10:20 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120409
Post by: racshot65 on 04/10/2012 11:14 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120410
Post by: racshot65 on 04/11/2012 10:26 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120411
Post by: racshot65 on 04/12/2012 11:43 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120412
Post by: racshot65 on 04/13/2012 04:06 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120413
Post by: racshot65 on 04/16/2012 10:18 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120416
Post by: racshot65 on 04/17/2012 11:54 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120417
Post by: racshot65 on 04/18/2012 11:17 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120418
Post by: jacqmans on 04/18/2012 10:47 pm
Dawn Gets Extra Time to Explore Vesta
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-107&cid=release_2012-107
PASADENA, Calif. – NASA’s Dawn mission has received official confirmation that 40 extra days have been added to its exploration of the giant asteroid Vesta, the second most massive object in the main asteroid belt. The mission extension allows Dawn to continue its scientific observations at Vesta until Aug. 26, while still arriving at the dwarf planet Ceres at the same originally scheduled target date in February 2015.
“We are leveraging our smooth and successful operations at Vesta to provide for even more scientific discoveries for NASA and the world.” said Robert Mase, Dawn project manager based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “This extra time will allow us to extend our scientific investigation and learn more about this mysterious world.”
The extension will not require any new funding, and will draw on financial reserves that have been carefully managed by the Dawn project. The flexibility provided by the spacecraft’s use of efficient ion propulsion system allows it to maintain its originally planned Ceres arrival.
The extension allows for extra observations at Dawn’s current low-altitude mapping orbit (average altitude 130 miles or 210 kilometers), which will now last until May 1. The additional time enables the gamma ray and neutron detector to build the best possible maps of the elemental composition of Vesta’s surface and improve data for the gravity experiment, the two primary scientific investigations at the low-altitude orbit. The spacecraft's camera and spectrometer are also obtaining additional high-resolution images.
Additional time will also be spent in the planned second high-altitude mapping orbit later this summer. When Dawn arrived at Vesta in July 2011, much of the northern hemisphere was in shadow. But with the passage of time, more of that area will bask in sunshine.
“Dawn has beamed back to us such dazzling Vestan vistas that we are happy to stay a little longer and learn more about this special world,” said Christopher Russell, Dawn’s principal investigator at UCLA. “While we have this one-of-a-kind opportunity to orbit Vesta, we want to make the best and most complete datasets that we can.”
Dawn's mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
For more information about the Dawn mission, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .
Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
[email protected]
- end -
Post by: racshot65 on 04/19/2012 08:40 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120418
Post by: racshot65 on 04/20/2012 10:26 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120420
Post by: racshot65 on 04/23/2012 08:50 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120423
Post by: racshot65 on 04/24/2012 10:21 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120424
Post by: racshot65 on 04/25/2012 10:35 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120425
Post by: jacqmans on 04/25/2012 06:58 pm
NASA DAWN SPACECRAFT REVEALS SECRETS OF GIANT ASTEROID VESTA
WASHINGTON -- Findings from NASA's Dawn spacecraft reveal new details
about the giant asteroid Vesta, including its varied surface
composition, sharp temperature changes and clues to its internal
structure. The findings were presented today at the European
Geosciences Union meeting in Vienna, Austria and will help scientists
better understand the early solar system and processes that dominated
its formation.
Spacecraft images, taken 420 miles (680 kilometers) and 130 miles (210
kilometers) above the surface of the asteroid, show a variety of
surface mineral and rock patterns. Coded false-color images help
scientists better understand Vesta's composition and enable them to
identify material that was once molten below the asteroid's surface.
Researchers also see breccias, which are rocks fused during impacts
from space debris. Many of the materials seen by Dawn are composed of
iron- and magnesium-rich minerals, which often are found in Earth's
volcanic rocks. Images also reveal smooth pond-like deposits, which
might have formed as fine dust created during impacts settled into
low regions.
"Dawn now enables us to study the variety of rock mixtures making up
Vesta's surface in great detail," said Harald Hiesinger, a Dawn
participating scientist at Münster University in Germany. "The images
suggest an amazing variety of processes that paint Vesta's surface."
At the Tarpeia crater near the south pole of the asteroid, Dawn
revealed bands of minerals that appear as brilliant layers on the
crater's steep slopes. The exposed layering allows scientists to see
farther back into the geological history of the giant asteroid.
The layers closer to the surface bear evidence of contamination from
space rocks bombarding Vesta's surface. Layers below preserve more of
their original characteristics. Frequent landslides on the slopes of
the craters also have revealed other hidden mineral patterns.
"These results from Dawn suggest Vesta's 'skin' is constantly
renewing," said Maria Cristina De Sanctis, lead of the visible and
infrared mapping spectrometer team based at Italy's National
Institute for Astrophysics in Rome.
Dawn has given scientists a near 3-D view into Vesta's internal
structure. By making ultrasensitive measurements of the asteroid's
gravitational tug on the spacecraft, Dawn can detect unusual
densities within its outer layers. Data now show an anomalous area
near Vesta's south pole, suggesting denser material from a lower
layer of Vesta has been exposed by the impact that created a feature
called the Rheasilvia basin. The lighter, younger layers coating
other parts of Vesta's surface have been blasted away in the basin.
Dawn obtained the highest-resolution surface temperature maps of any
asteroid visited by a spacecraft. Data reveal temperatures can vary
from as warm as -10 degrees Fahrenheit (-23 degrees Celsius) in the
sunniest spots to as cold as -150 degrees Fahrenheit (-100 degrees
Celsius) in the shadows. This is the lowest temperature measurable by
Dawn. These findings show the surface responds quickly to
illumination with no mitigating effect of an atmosphere.
"After more than nine months at Vesta, Dawn's suite of instruments has
enabled us to peel back the layers of mystery that have surrounded
this giant asteroid since humankind first saw it as just a bright
spot in the night sky," said Carol Raymond, Dawn deputy principal
investigator at NASA's Jet Propulsion Laboratory (JPL) in Pasadena,
Calif. "We are closing in on the giant asteroid's secrets."
Launched in 2007, Dawn began its exploration of the approximately
330-mile- (530-kilometer-) wide asteroid in mid-2011. The
spacecraft's next assignment will be to study the dwarf planet Ceres
in 2015. These two icons of the asteroid belt have been witness to
much of our solar system's history.
Dawn's mission is managed by JPL for NASA's Science Mission
Directorate in Washington. Dawn is a project of the directorate's
Discovery Program, managed by NASA's Marshall Space Flight Center in
Huntsville, Ala. UCLA is responsible for overall Dawn mission
science. Orbital Sciences Corp. in Dulles, Va., designed and built
the spacecraft. The German Aerospace Center, the Max Planck Institute
for Solar System Research, the Italian Space Agency and the Italian
National Astrophysical Institute are international partners on the
mission team.
To view the new images and for more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: racshot65 on 04/26/2012 09:36 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120426
Post by: racshot65 on 04/27/2012 10:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120427
Post by: racshot65 on 04/30/2012 09:46 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120430
Post by: racshot65 on 05/01/2012 12:02 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120501
( Note that the large dark patches with bright rims in the left of the image are artifacts that result from the processing of the image and are not features on Vesta’s surface.)
Post by: racshot65 on 05/02/2012 03:05 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120502
Post by: racshot65 on 05/03/2012 01:31 pm
Quote
May 1, 2012 - Dawn Concludes Outstandingly Successful Low Altitude Phase
Investigating Vesta since December 12 from an average altitude of 210 kilometers (130 miles), Dawn accumulated an extraordinary amount of information about this unique world. Now having exceeded all expectations for this phase of the mission, it began its six-week ascent to a higher orbit on May 1.
Dawn's orbital stay at Vesta is being extended by 40 days, and that allowed it to remain at low altitude for an extra month, performing even more observations. Additional time will be spent in higher orbits as well before it departs on August 26, 2012 for the long journey to Ceres.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 05/03/2012 01:31 pm
http://dawn.jpl.nasa.gov/mission/journal_04_30_12.asp
Post by: racshot65 on 05/03/2012 01:33 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120503
Post by: racshot65 on 05/04/2012 10:18 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120504
Post by: racshot65 on 05/07/2012 10:05 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120507
Post by: jacqmans on 05/07/2012 07:59 pm
NASA TO HOLD NEWS CONFERENCE ON ASTEROID MISSION RESULTS
WASHINGTON -- NASA will host a news conference on Thursday, May 10, at
2 p.m. EDT to present a new analysis of the giant asteroid Vesta
using data from the agency's Dawn spacecraft.
The event will be held in the James E. Webb Auditorium at NASA
Headquarters located at 300 E St. SW in Washington. The event will be
broadcast live on NASA Television and streamed on the agency's
website. The journal Science has embargoed the findings prior to the
news conference.
The panelists for the briefing are:
-- Carol Raymond, Dawn deputy principal investigator, NASA's Jet
Propulsion Laboratory, Pasadena, Calif.
-- Harry McSween, chair, Dawn surface composition working group,
University of Tennessee, Knoxville
-- Vishnu Reddy, Dawn framing camera team member, Max Planck Institute
for Solar System Research, Katlenburg-Lindau, Germany, and the
University of North Dakota, Grand Forks
-- David O'Brien, Dawn participating scientist, Planetary Science
Institute, Tucson, Ariz.
-- Maria Cristina De Sanctis, Dawn co-investigator and visible and
infrared mapping spectrometer team lead, Italian National Institute
for Astrophysics, Rome
Reporters unable to attend the briefing in-person can ask questions
from other NASA centers, by telephone or via Twitter using the
hashtag #asknasa. To obtain dial-in information, journalists must
send their name, affiliation and telephone number to
[email protected] by noon on May 10.
For NASA TV streaming video, downlink and scheduling information,
visit:
http://www.nasa.gov/ntv
The event will be streamed live on Ustream with a moderated chat
available at:
http://www.ustream.com/nasajpl2
For more information about Dawn, visit:
http://www.nasa.gov/dawn
Post by: Bubbinski on 05/07/2012 08:30 pm
Edited to add: is this finding why they're spending 40 more days at Vesta?
Post by: robertross on 05/07/2012 11:50 pm
As great as this extension is, I'm really pumped for Dawn to get going on to CeresQuoteMay 1, 2012 - Dawn Concludes Outstandingly Successful Low Altitude Phase
Investigating Vesta since December 12 from an average altitude of 210 kilometers (130 miles), Dawn accumulated an extraordinary amount of information about this unique world. Now having exceeded all expectations for this phase of the mission, it began its six-week ascent to a higher orbit on May 1.
Dawn's orbital stay at Vesta is being extended by 40 days, and that allowed it to remain at low altitude for an extra month, performing even more observations. Additional time will be spent in higher orbits as well before it departs on August 26, 2012 for the long journey to Ceres.
http://dawn.jpl.nasa.gov/mission/status.asp
Edit: yes Ceres, not Vesta.
Post by: Nomadd on 05/08/2012 12:11 am
I agree with robertross.
Post by: Robotbeat on 05/08/2012 02:51 am
The first science fiction book I ever read was when Lyndon Johnson was president and was about miners on Ceres. It's been locked in my head as the place I'd most like to see since I was 11 years old.Ceres is the only thing that we haven't got a decent picture of that's significantly inside the orbit of Pluto and that's even close to be big enough for getting to hydrostatic equilibrium. It's the last planet-like thing that could be in reach of a human mission some time in any of our lifetimes which we haven't had a good look at, yet. For that reason, it inspires the imagination in me...
I'm guessing robertross meant to say Ceres, which would put me in agreement with him.
We think it could very well have a significant ocean (covered with ice), like some of the moons of Jupiter and Saturn (but without the enormous distance of either or the radiation of Jupiter). May even have some sort of thin atmosphere.
Post by: racshot65 on 05/08/2012 10:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120508
Post by: racshot65 on 05/09/2012 08:20 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120509
Post by: quixote on 05/09/2012 08:29 pm
Post by: racshot65 on 05/09/2012 08:46 pm
racshot65, just curious -- do you go download and then upload all these pictures manually?
Yep :)
Post by: clongton on 05/09/2012 08:53 pm
racshot65, just curious -- do you go download and then upload all these pictures manually?
Yep :)
Thank you Soooo much!
Post by: baldusi on 05/09/2012 08:59 pm
There are not enough words to thank you!racshot65, just curious -- do you go download and then upload all these pictures manually?
Yep :)
Post by: Robotbeat on 05/09/2012 09:01 pm
Add my voice to the chorus of thank-yous. :)racshot65, just curious -- do you go download and then upload all these pictures manually?
Yep :)
Post by: quixote on 05/09/2012 10:45 pm
racshot65, just curious -- do you go download and then upload all these pictures manually?
Yep :)
That is a truly impressive commitment of both time and effort. Thanks so much!
Post by: Bubbinski on 05/10/2012 05:10 am
Edited to also add: Tomorrow's the press conference. They're having it live on NASA TV, which I can't watch as I'd be at work. I'll be keeping up with this thread.
Post by: racshot65 on 05/10/2012 08:35 am
Quote
Dawn Raising Orbital Altitude
The spacecraft is gradually raising its orbital altitude with its ion propulsion system, spiraling upward in a reverse of the method it used in November and December to reach the low altitude orbit. Dawn's altitude is constantly changing, but today the ship's average altitude is about 275 kilometers (170 miles).
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: MATTBLAK on 05/10/2012 10:07 am
Post by: Robotbeat on 05/10/2012 06:04 pm
On to the mysterious dwarf planet Ceres!QuoteDawn Raising Orbital Altitude
The spacecraft is gradually raising its orbital altitude with its ion propulsion system, spiraling upward in a reverse of the method it used in November and December to reach the low altitude orbit. Dawn's altitude is constantly changing, but today the ship's average altitude is about 275 kilometers (170 miles).
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: jacqmans on 05/10/2012 08:54 pm
NASA DAWN SPACECRAFT REVEALS SECRETS OF LARGE ASTEROID
WASHINGTON -- NASA's Dawn spacecraft has provided researchers with the
first orbital analysis of the giant asteroid Vesta, yielding new
insights into its creation and relation to the terrestrial planets
and Earth's moon.
Vesta now has been revealed as a special fossil of the early solar
system with a more varied, diverse surface than originally thought.
Scientists have confirmed a variety of ways Vesta more closely
resembles a small planet or Earth's moon than another asteroid.
Results appear in today's edition of the journal Science.
"Dawn's visit to Vesta has confirmed our broad theories of this giant
asteroid's history, while helping to fill in details it would have
been impossible to know from afar," said Carol Raymond, deputy
principal investigator at NASA's Jet Propulsion Laboratory (JPL) in
Pasadena, Calif. "Dawn's residence at Vesta of nearly a year has made
the asteroid's planet-like qualities obvious and shown us our
connection to that bright orb in our night sky."
Scientists now see Vesta as a layered, planetary building block with
an iron core - the only one known to survive the earliest days of the
solar system. The asteroid's geologic complexity can be attributed to
a process that separated the asteroid into a crust, mantle and iron
core with a radius of approximately 68 miles (110 kilometers) about
4.56 billion years ago. The terrestrial planets and Earth's moon
formed in a similar way.
Dawn observed a pattern of minerals exposed by deep gashes created by
space rock impacts, which may support the idea the asteroid once had
a subsurface magma ocean. A magma ocean occurs when a body undergoes
almost complete melting, leading to layered building blocks that can
form planets. Other bodies with magma oceans ended up becoming parts
of Earth and other planets.
Data also confirm a distinct group of meteorites found on Earth did,
as theorized, originate from Vesta. The signatures of pyroxene, an
iron- and magnesium-rich mineral, in those meteorites match those of
rocks on Vesta's surface. These objects account for about 6 percent
of all meteorites seen falling on Earth.
This makes the asteroid one of the largest single sources for Earth's
meteorites. The finding also marks the first time a spacecraft has
been able to visit the source of samples after they were identified
on Earth.
Scientists now know Vesta's topography is quite steep and varied. Some
craters on Vesta formed on very steep slopes and have nearly vertical
sides, with landslides occurring more frequently than expected.
Another unexpected finding was that the asteroid's central peak in the
Rheasilvia basin in the southern hemisphere is much higher and wider,
relative to its crater size, than the central peaks of craters on
bodies like our moon. Vesta also bears similarities to other
low-gravity worlds like Saturn's small icy moons, and its surface has
light and dark markings that don't match the predictable patterns on
Earth's moon.
"We know a lot about the moon and we're only coming up to speed now on
Vesta," said Vishnu Reddy, a framing camera team member at the Max
Planck Institute for Solar System Research in Germany and the
University of North Dakota in Grand Forks. "Comparing the two gives
us two storylines for how these fraternal twins evolved in the early
solar system."
Dawn has revealed details of ongoing collisions that battered Vesta
throughout its history. Dawn scientists now can date the two giant
impacts that pounded Vesta's southern hemisphere and created the
basin Veneneia approximately 2 billion years ago and the Rheasilvia
basin about 1 billion years ago. Rheasilvia is the largest impact
basin on Vesta.
"The large impact basins on the moon are all quite old," said David
O'Brien, a Dawn participating scientist from the Planetary Science
Institute in Tucson, Ariz. "The fact that the largest impact on Vesta
is so young was surprising."
Launched in 2007, Dawn began exploring Vesta in mid-2011. The
spacecraft will depart Vesta on August 26 for its next study target,
the dwarf planet Ceres, in 2015.
Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science
Mission Directorate in Washington. Dawn is a project of the
directorate's Discovery Program managed by NASA's Marshall Space
Flight Center in Huntsville, Ala. UCLA is responsible for overall
Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed
and built the spacecraft. The German Aerospace Center, the Max Planck
Institute for Solar System Research, the Italian Space Agency and the
Italian National Astrophysical Institute are international partners
on the mission team.
For images and videos related to the findings, visit:
http://www.nasa.gov/mission_pages/dawn/news/dawn20120510.html
For more information about the Dawn mission, visit:
http://www.nasa.gov/dawn
Post by: John44 on 05/10/2012 09:00 pm
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=7553
Post by: ChrisC on 05/11/2012 01:26 am
Post by: racshot65 on 05/11/2012 09:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120511
Post by: racshot65 on 05/14/2012 10:28 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120514
Post by: racshot65 on 05/15/2012 08:55 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120515
Post by: racshot65 on 05/16/2012 07:27 am
Quote
May 15, 2012
Dawn Continuing to Spiral Higher
Dawn's ascent to its next mapping orbit at an altitude of about 680 kilometers (420 miles) is progressing smoothly. As it uses its ion propulsion system to follow the complicated orbital route to the new target, today the probe's average altitude is about 355 kilometers (220 miles).
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 05/16/2012 07:27 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120516
Post by: racshot65 on 05/18/2012 09:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120517
Post by: racshot65 on 05/18/2012 09:13 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120518
Post by: racshot65 on 05/21/2012 09:49 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120521
Post by: racshot65 on 05/22/2012 03:58 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120522
Post by: racshot65 on 05/23/2012 10:58 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120523
Post by: racshot65 on 05/24/2012 04:44 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120524
Post by: racshot65 on 05/24/2012 04:50 pm
Quote
Dawn's Climb to New Orbit Proceeding Well
Dawn continues to use its ion propulsion system to change its orbit around Vesta so it can conduct new observations. Today the spacecraft's average altitude is about 450 kilometers (280 miles).
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 05/25/2012 08:50 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120525
Post by: racshot65 on 05/28/2012 08:37 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120528
Post by: clongton on 05/28/2012 12:02 pm
Grooved surface
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120528
Groovy :)
Post by: racshot65 on 05/29/2012 05:20 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120529
Post by: racshot65 on 05/30/2012 07:08 pm
Quote
Dawn Progressing to Next Mapping Orbit
Dawn is making good progress to its next mapping orbit, thrusting with its ion propulsion system and sometimes using Vesta's gravity for a free ride. Today the craft's average altitude is about 590 kilometers (365 miles).
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 05/31/2012 09:05 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120530
Post by: racshot65 on 05/31/2012 09:05 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120531
Post by: racshot65 on 06/01/2012 04:01 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120601
Post by: racshot65 on 06/02/2012 10:20 am
http://dawn.jpl.nasa.gov/mission/journal_05_31_12.asp
Post by: racshot65 on 06/04/2012 10:16 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120604
Post by: racshot65 on 06/05/2012 09:21 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120605
Post by: racshot65 on 06/06/2012 06:37 pm
http://www.jpl.nasa.gov/news/news.cfm?release=2012-156
Post by: racshot65 on 06/07/2012 09:23 am
Quote
Dawn Nearly in Targeted Orbit
Dawn's complex spiral course from its low-altitude mapping orbit to its second high-altitude mapping orbit has been extremely smooth.
It is now at the planned altitude of about 680 kilometers (420 miles). As described in the latest Dawn Journal, the spacecraft also needed to change the angle of its orbit plane from the sun, and that has been accomplished as well.
Navigators now will make accurate measurements of the new orbit and then controllers will use the ion propulsion system to fine tune it to match exactly the conditions needed for the next intensive observation campaign, scheduled to begin on June 15.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 06/07/2012 07:49 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120607
Post by: racshot65 on 06/08/2012 10:42 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120608
Post by: racshot65 on 06/12/2012 09:44 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120611
Post by: racshot65 on 06/12/2012 09:45 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120612
Post by: racshot65 on 06/13/2012 09:46 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120613
Post by: racshot65 on 06/14/2012 06:15 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120614
Post by: racshot65 on 06/15/2012 09:26 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120615
Post by: racshot65 on 06/15/2012 09:26 am
http://www.jpl.nasa.gov/news/news.cfm?release=2012-175
Post by: racshot65 on 06/16/2012 09:29 am
Quote
Dawn Begins New Observation Campaign
In its new orbit, known as the second high-altitude mapping orbit (HAMO2), Dawn began using its visible and infrared mapping spectrometer today to observe Vesta. The spacecraft is at an altitude of about 680 kilometers (420 miles), circling Vesta every 12 hours.
The operations team determined that spiral flight from the low-altitude mapping orbit to HAMO2 was executed so accurately that the fine tuning described in the June 5 mission status was not necessary.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 06/18/2012 10:03 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120618
Post by: racshot65 on 06/19/2012 09:37 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120619
Post by: racshot65 on 06/20/2012 10:02 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120620
Post by: racshot65 on 06/21/2012 01:07 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120621
Post by: racshot65 on 06/22/2012 02:57 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120622
Post by: racshot65 on 06/25/2012 09:35 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120625
Post by: racshot65 on 06/25/2012 09:37 pm
Quote
Dawn Begins Photographing Vesta Again
Dawn has resumed taking pictures of Vesta. As in the mapping performed in October 2011, the first five-day cycle of mapping will be conducted looking straight down. In addition, the spacecraft is continuing to scrutinize Vesta with its visible and infrared mapping spectrometer. In each orbit, lasting just over 12 hours, Dawn aims its instruments at the surface when it is over the day side of Vesta, and it points its main antenna to Earth to transmit the data when it is over the night side.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 06/26/2012 01:15 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120626
Post by: racshot65 on 06/27/2012 12:05 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120627
Post by: racshot65 on 06/28/2012 09:46 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120628
Post by: racshot65 on 06/29/2012 09:43 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120629
Post by: racshot65 on 07/02/2012 09:31 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120702
Post by: racshot65 on 07/03/2012 09:50 am
Quote
Dawn Begins Stereo Imaging
Dawn successfully completed its first mapping cycle, and its second begins today. Instead of pointing the camera directly at the surface beneath it, the spacecraft is aiming it a little ahead and to the left. These images will provide a stereo view so scientists can develop a topographical map. In addition to the pictures, Dawn is using its visible and infrared mapping spectrometer to measure the nature of the minerals.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 07/03/2012 09:51 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120703
Post by: racshot65 on 07/05/2012 10:07 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120705
Post by: racshot65 on 07/06/2012 10:20 am
Quote
Dawn Completes First Stereo Mapping Cycle
Dawn has collected another complete set of images of the illuminated surface of Vesta. In this second of six planned mapping cycles, the spacecraft pointed the camera at an angle instead of straight down in order to acquire images for a topographical map. Today the probe began the third mapping cycle, now with the camera pointed both behind and a little to the left of the point directly beneath it. Dawn is continuing to acquire visible and infrared spectra as well.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 07/06/2012 10:21 am
http://dawn.jpl.nasa.gov/mission/journal_06_30_12.asp (http://dawn.jpl.nasa.gov/mission/journal_06_30_12.asp)
Post by: racshot65 on 07/06/2012 10:21 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120706
Post by: racshot65 on 07/09/2012 10:24 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120709
Post by: racshot65 on 07/10/2012 09:36 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120710
Post by: racshot65 on 07/11/2012 10:40 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120711
Post by: racshot65 on 07/12/2012 10:08 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120712
Post by: racshot65 on 07/13/2012 11:09 am
Quote
Dawn Continues Topographical Mapping
Dawn completed its third cycle of mapping Vesta while simultaneously collecting visible and infrared spectra. In the fourth mapping cycle, which begins today, the spacecraft will aim the sensors at the surface behind and to the right as it orbits. As described in the June Dawn Journal, the images will provide another new view for scientists to use in developing a topographical map of some regions of the previously unseen northern hemisphere.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 07/13/2012 11:09 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120713
Post by: racshot65 on 07/16/2012 09:43 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120716
Post by: racshot65 on 07/17/2012 09:49 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120717
Post by: racshot65 on 07/18/2012 06:50 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120718
Post by: racshot65 on 07/19/2012 09:47 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120719
Post by: racshot65 on 07/20/2012 04:13 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120720
Post by: racshot65 on 07/20/2012 04:13 pm
Quote
Dawn Concludes Topographical Mapping
Dawn completed the fifth cycle of mapping Vesta today. This was the last cycle to gather stereo images for the development of a topographical map of the newly illuminated regions of the northern hemisphere. The final cycle, like the first, will observe the terrain directly underneath the spacecraft. The visible and infrared mapping spectrometer continues to collect data in the same direction the camera is pointed.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 07/23/2012 09:42 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120723
Post by: racshot65 on 07/24/2012 09:58 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120724
Post by: racshot65 on 07/25/2012 10:15 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120725
Post by: racshot65 on 07/26/2012 09:39 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120726
Post by: racshot65 on 07/28/2012 10:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120727
Post by: racshot65 on 07/28/2012 10:13 am
http://dawn.jpl.nasa.gov/mission/journal_07_25_12.asp
Post by: racshot65 on 07/28/2012 10:13 am
Quote
Dawn Completes Mapping Vesta and Begins its Departure
Dawn successfully completed its mapping of Vesta. The probe collected a rich set of pictures and other scientific data from this intensive phase of its exploration.
Now the spacecraft is using its ion propulsion system to gradually raise its orbit so it can escape from Vesta in late August and head for its appointment with dwarf planet Ceres in 2015. It will pause four more times to observe Vesta as it departs.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 07/30/2012 11:32 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120730
Post by: racshot65 on 08/01/2012 11:10 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120731
Post by: racshot65 on 08/02/2012 10:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120802
Post by: racshot65 on 08/03/2012 10:16 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120803
Post by: racshot65 on 08/06/2012 07:30 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120806
Post by: racshot65 on 08/07/2012 08:26 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120807
Post by: racshot65 on 08/08/2012 09:42 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120808
Post by: racshot65 on 08/09/2012 11:45 am
Quote
Dawn Continues Raising Orbital Altitude
Dawn is devoting most of its time to using its ion propulsion system to spiral away from Vesta after its extraordinarily productive exploration of the giant protoplanet. Today the spacecraft's average altitude is 1900 kilometers (1200 miles).
As explained in the most recent Dawn Journal, the probe is scheduled to observe Vesta several times during its departure..
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 08/09/2012 11:45 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120809
Post by: racshot65 on 08/10/2012 10:14 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120810 (http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120810)
Post by: Robotbeat on 08/10/2012 04:14 pm
HAMO and LAMO images of Arruntia craterNice!
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120810 (http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120810)
Post by: racshot65 on 08/13/2012 10:50 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120813
Post by: racshot65 on 08/14/2012 10:34 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120814
Post by: racshot65 on 08/14/2012 10:35 am
Quote
Departure Delayed By Balky Reaction Wheel
Dawn interrupted its spiral ascent on August 8 when one of its reaction wheels, used for precise pointing, experienced increased friction. Another reaction wheel exhibited the same behavior in June 2010. As before, protective software turned the wheel off and used the small hydrazine jets to control the pointing. The spacecraft's orbital altitude is more than 2100 kilometers (1300 miles).
Controllers discovered the condition during a routine communications session on August 9. They are now replanning the departure and expect to resume ion thrusting at the end of next week. Escape from Vesta will be delayed by about 10 days, and then the spacecraft will be on its way to Ceres. (The flight from Vesta to Ceres was already planned to be performed with all the reaction wheels turned off.) To make up some of the time, most of the bonus departing observations will not be conducted.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 08/14/2012 10:35 am
http://www.jpl.nasa.gov/news/news.cfm?release=2012-242
Post by: robertross on 08/14/2012 12:48 pm
Dawn Engineers Assess Reaction Wheel
http://www.jpl.nasa.gov/news/news.cfm?release=2012-242
eeww
I hope they last.
One would have hoped that lessons learned from Hubble's issues (assuming a similar design) would have translated into longer-lasting reaction wheels.
(and also my hope that one day, with commercial orbiting labs, that perfect bearings can be manufactured for just such critical applications)
Post by: Nomadd on 08/14/2012 03:51 pm
I thought Hubble's problem was the gyros.
Post by: racshot65 on 08/15/2012 09:24 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120815
Post by: MATTBLAK on 08/15/2012 10:17 am
If they're not sure they'll probably just use thrusters for all manuevering and save the reaction wheels for precision pointing during the science phase.
I thought Hubble's problem was the gyros.
How many reaction wheels are spacecraft like Dawn equipped with: 3 or 4 in total? If all fail, I'm concerned that the RCS propellant could eventually be consumed enough to prevent an extended mission once Dawn reaches Ceres. Much as I've loved looking at Vesta, Ceres is what I'm hanging out for. Perhaps they should cancel the extended Vesta mission and get going for Ceres A.S.A.P.
Post by: Hungry4info3 on 08/15/2012 07:09 pm
Perhaps they should cancel the extended Vesta mission and get going for Ceres A.S.A.P.
They are already leaving Vesta, spiraling up to an escape trajectory.
Post by: racshot65 on 08/16/2012 09:29 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120816
Post by: racshot65 on 08/17/2012 10:29 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120817
Post by: racshot65 on 08/18/2012 11:01 am
Quote
Dawn Resumes Departure Spiral
Mission controllers returned Dawn to a standard operating configuration earlier this week after the reaction wheel developed increased friction. The spacecraft is now using its small hydrazine thrusters to control its orientation instead of the reaction wheels, just as it did from August 2010 to May 2011.
Ion thrusting to follow the departure spiral will resume later today. Because of the hiatus in thrusting, escape will occur on September 5.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: clongton on 08/18/2012 07:20 pm
QuoteDawn Resumes Departure Spiral
Mission controllers returned Dawn to a standard operating configuration earlier this week after the reaction wheel developed increased friction. The spacecraft is now using its small hydrazine thrusters to control its orientation instead of the reaction wheels, just as it did from August 2010 to May 2011.
Ion thrusting to follow the departure spiral will resume later today. Because of the hiatus in thrusting, escape will occur on September 5.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Ceres here we come!
Post by: sdsds on 08/18/2012 08:24 pm
http://www.sciencenews.org/view/generic/id/343061/title/Dawn_mission_to_die_another_day
The author draws a parallel to Kepler, which recently lost one of its four reaction wheels.
Post by: racshot65 on 08/20/2012 10:19 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120820
Post by: racshot65 on 08/20/2012 06:56 pm
Quote
Dawn Continues Ascent
Dawn is continuing its gradual departure from Vesta. Today its average altitude is nearly 3000 kilometers (about 1850 miles). The last time it was this far from Vesta was August 1, 2011, near the beginning of its exploration of Vesta.
The September issue of Discover Magazine has an extensive article about Dawn's amazing mission at Vesta.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 08/21/2012 04:02 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120821
Post by: racshot65 on 08/22/2012 10:22 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120822
Post by: racshot65 on 08/23/2012 09:12 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120823
Post by: racshot65 on 08/24/2012 09:04 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120824
Post by: racshot65 on 08/27/2012 09:58 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120827
Post by: racshot65 on 08/28/2012 12:14 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120828
Post by: racshot65 on 08/29/2012 01:07 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120829
Post by: racshot65 on 08/30/2012 11:06 am
Quote
Dawn Takes a Parting Shot as it Ascends
Dawn's departure spiral has continued smoothly.
On August 25 - 26, at an altitude of 6,000 kilometers (3,700 miles), Dawn pointed its instruments at Vesta one last time for some final bonus observations. It took pictures and made other measurements of the northern hemisphere to see a little more terrain that has become illuminated since Dawn's previous observations in July. As Vesta's seasons progress, the equinox was on August 20, so the sun is now north of Vesta's equator for the first time since Dawn has been at Vesta.
http://dawn.jpl.nasa.gov/mission/status.asp (http://dawn.jpl.nasa.gov/mission/status.asp)
Post by: racshot65 on 08/30/2012 11:07 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120830
Post by: racshot65 on 08/30/2012 07:15 pm
http://www.jpl.nasa.gov/news/news.php?release=2012-271
Post by: catdlr on 08/30/2012 07:24 pm
Published on Aug 30, 2012 by JPLnews
A simulated flyover of the most intriguing landmarks on giant asteroid Vesta, as seen by NASA's Dawn spacecraft.
http://www.youtube.com/watch?v=84vz6J8cnc8
Post by: clongton on 08/31/2012 01:42 am
Dawn's Farewell Portrait of Giant Asteroid Vesta
Published on Aug 30, 2012 by JPLnews
A simulated flyover of the most intriguing landmarks on giant asteroid Vesta, as seen by NASA's Dawn spacecraft.
THAT is an AWESOME video.
Thank you.
Post by: racshot65 on 08/31/2012 10:10 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120831
Post by: kfsorensen on 09/01/2012 09:12 pm
Dawn's Farewell Portrait of Giant Asteroid Vesta
Published on Aug 30, 2012 by JPLnews
A simulated flyover of the most intriguing landmarks on giant asteroid Vesta, as seen by NASA's Dawn spacecraft.
http://www.youtube.com/watch?v=84vz6J8cnc8
Absolutely breathtaking. What a great mission Dawn has been.
Post by: racshot65 on 09/04/2012 09:51 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120904
Post by: TheFallen on 09/04/2012 09:04 pm
http://dawn.jpl.nasa.gov/mission/live_shots.asp
Post by: clongton on 09/05/2012 01:41 am
As intently interested as I have been in everything that has been posted here (my profound thanks to Aaron) plus what else I could glean from other sources about Vesta, my personal main excitement is aimed at Ceres. It's a water world, the only other such in the solar system besides the earth.
Post by: Robotbeat on 09/05/2012 02:15 am
And so we now bid Vesta a fond farewell. Next stop Ceres.Half a dozen moons just cleared their throats. ;)
As intently interested as I have been in everything that has been posted here (my profound thanks to Aaron) plus what else I could glean from other sources about Vesta, my personal main excitement is aimed at Ceres. It's a water world, the only other such in the solar system besides the earth.
Post by: clongton on 09/05/2012 02:17 am
And so we now bid Vesta a fond farewell. Next stop Ceres.Half a dozen moons just cleared their throats. ;)
As intently interested as I have been in everything that has been posted here (my profound thanks to Aaron) plus what else I could glean from other sources about Vesta, my personal main excitement is aimed at Ceres. It's a water world, the only other such in the solar system besides the earth.
:) Optimum word is "world", not "moon". If it weren't for some funky word-smithing, Ceres would be called a planet.
Post by: QuantumG on 09/05/2012 02:27 am
:) Optimum word is "world", not "moon". If it weren't for some funky word-smithing, Ceres would be called a planet.
It is.
http://en.wikipedia.org/wiki/Ceres_%28dwarf_planet%29
Post by: ugordan on 09/05/2012 07:55 am
It's a water world, the only other such in the solar system besides the earth.
How so? What about Mars?
:) Optimum word is "world", not "moon". If it weren't for some funky word-smithing, Ceres would be called a planet.
A moon is a world and those icy moons that "cleared their throat" are just as much worlds as this planet wannabe is. Just because they are moons doesn't mean their water is less worthy of attention. Heck, a number of them have pretty convincingly been shown to harbor liquid water under the ice.
Post by: clongton on 09/05/2012 09:59 am
Post by: ugordan on 09/05/2012 11:11 am
Ceres otoh is in a location where it can become the focal point of the solar system in terms of exploration. It's water can fuel and sustain the entire exploration fleet and even eventually the entire commercial fleet. Ceres, as a huge water world, can be a genuine enabler.
I am not going to argue that, but that point by no means follows from your statement "It's a water world, the only other such in the solar system besides the earth" and the resulting word games about world/moon.
Post by: kfsorensen on 09/05/2012 03:12 pm
Ceres otoh is in a location where it can become the focal point of the solar system in terms of exploration. It's water can fuel and sustain the entire exploration fleet and even eventually the entire commercial fleet. Ceres, as a huge water world, can be a genuine enabler. None of the others can say that - they are simply too far away and live in too hostile an environment. They might eventually become important to local operations in their particular neighborhoods only, but Ceres is easily reachable and can open the *entire* solar system. That's what makes Ceres so important. And that's why we should be going to Ceres before we go to the Martian surface.
Its ten-degree orbital inclination relative to the ecliptic plane makes that very difficult.
Post by: Robotbeat on 09/05/2012 04:16 pm
Ceres otoh is in a location where it can become the focal point of the solar system in terms of exploration. It's water can fuel and sustain the entire exploration fleet and even eventually the entire commercial fleet. Ceres, as a huge water world, can be a genuine enabler. None of the others can say that - they are simply too far away and live in too hostile an environment...I agree (not quite so strongly about the feasibility of using it to mine water), but I was just pointing out that there are PLENTY of water worlds in our solar system ("world" is usually considered inclusive of both large moons and planets, dwarf or otherwise), many of which are larger than Ceres.
Ceres is just the closest of these icy/watery worlds. Certainly not the largest. Ganymede, the largest moon in the solar system (and larger than Ceres, our Moon, Pluto, and even Mercury), probably has a liquid ocean: http://www.jpl.nasa.gov/releases/2000/aguganymederoundup.html (and the pressure there is still of the same order of magnitude as the deepest part of the Earth's ocean, meaning life should be possible there).
(and so probably does Callisto, which is relevant since it is far enough from Jupiter's radiation belts to make a manned surface mission there feasible... and the pressure in its ocean is about the same as where James Cameroon recently visited)
Post by: catdlr on 09/05/2012 07:33 pm
Dawn's Greatest Hits at Vesta
Published on Sep 5, 2012 by JPLnews
This video highlights Dawn's top accomplishments during its orbit around the giant asteroid Vesta.
http://www.youtube.com/watch?v=vSS8yuk4bDw
Post by: clongton on 09/05/2012 09:05 pm
Ceres otoh is in a location where it can become the focal point of the solar system in terms of exploration. It's water can fuel and sustain the entire exploration fleet and even eventually the entire commercial fleet. Ceres, as a huge water world, can be a genuine enabler. None of the others can say that - they are simply too far away and live in too hostile an environment...I agree (not quite so strongly about the feasibility of using it to mine water), but I was just pointing out that there are PLENTY of water worlds in our solar system ("world" is usually considered inclusive of both large moons and planets, dwarf or otherwise), many of which are larger than Ceres.
Ceres is just the closest of these icy/watery worlds. Certainly not the largest. Ganymede, the largest moon in the solar system (and larger than Ceres, our Moon, Pluto, and even Mercury), probably has a liquid ocean: http://www.jpl.nasa.gov/releases/2000/aguganymederoundup.html (and the pressure there is still of the same order of magnitude as the deepest part of the Earth's ocean, meaning life should be possible there).
(and so probably does Calisto, which is relevant since it is far enough from Jupiter's radiation belts to make a manned surface mission there feasible... and the pressure in its ocean is about the same as where James Cameroon recently visited)
For the foreseeable future manned exploration (assuming we even get to do that) will be limited to the inner system. While I concur with your observation wrt the Jovan and Saturnian moons, they are non-players in water world usefulness; they're just too far away and we (manned) won't be going to either of them any time soon.
Ceres otoh is reachable and feasible with today’s technology. Don't get me wrong. I'm not saying that the other moons (which are *all* in the outer system) will never have a part to play. What I am saying is that only Ceres can fill this role for a very, very long time to come. Actually imo we will never even get to them unless we can first extract the water from Ceres for propellant. Essentially Calisto and Ganymede just don't enter into the equation in any reasonable way. Nobody is going to go to moons in the outer system to extract water to enable exploration/commerce in the inner system, which is where we will be confined for several generations (if we are lucky). Ceres can make it possible. Without Ceres, inner system exploration on any meaningful scale just won’t happen (until we develop warp engines :) ). Everything else takes propellant, which will be abundantly available from Ceres alone.
How so? What about Mars?
There is water on Mars, but Mars is not a water world. Any water extracted on Mars will be used on Mars, not exported.
Post by: racshot65 on 09/05/2012 09:46 pm
http://www.jpl.nasa.gov/news/news.php?release=2012-277
Post by: Carl G on 09/06/2012 12:19 am
Post by: racshot65 on 09/06/2012 10:32 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120906
Post by: racshot65 on 09/07/2012 09:50 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120907
Post by: racshot65 on 09/11/2012 09:46 am
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120910
Post by: catdlr on 09/11/2012 09:42 pm
Vesta in Dawn's Rear View Mirror
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2012-284&cid=release_2012-284
PASADENA, Calif. – NASA's Dawn mission is releasing two parting views of the giant asteroid Vesta, using images that were among the last taken by the spacecraft as it departed its companion for the last year.
The first set of images is a color-coded relief map of Vesta's northern hemisphere, from the pole to the equator. It incorporates images taken just as Dawn began to creep over the high northern latitudes, which were dark when Dawn arrived in July 2011. The other image is a black-and-white mosaic that shows a full view of the giant asteroid, created by synthesizing some of Dawn's best images.
"Dawn has peeled back the veil on some of the mysteries surrounding Vesta, but we're still working hard on more analysis," said Christopher Russell, Dawn's principal investigator at UCLA. "So while Vesta is now out of sight, it will not be out of mind."
These will be the last daily images during the cruise to Dawn's second destination, the dwarf planet Ceres. Other images will be highlighted as findings are made. Other data will be archived at http://pds.nasa.gov.
Dawn left Vesta on Sept. 4, 2012 PDT (Sept. 5, 2012 EDT). The spacecraft is using its ion propulsion system to travel to Ceres. It is expected to arrive in early 2015.
JPL manages the Dawn mission for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. The University of California at Los Angeles (UCLA) is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. The California Institute of Technology in Pasadena manages JPL for NASA.
For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .
Jia-Rui Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
[email protected]
- end -
Post by: racshot65 on 09/12/2012 10:21 pm
http://dawn.jpl.nasa.gov/multimedia/imageoftheday/image.asp?date=20120911
Post by: racshot65 on 09/20/2012 09:02 pm
http://www.jpl.nasa.gov/news/news.php?release=2012-297
Post by: racshot65 on 09/27/2012 10:03 am
http://www.jpl.nasa.gov/news/news.php?release=2012-304
Post by: clongton on 09/27/2012 11:12 am
Giant Asteroid's Troughs Suggest Stunted Planet
http://www.jpl.nasa.gov/news/news.php?release=2012-304
Hi Aaron
I have speculated about those troughs and my admittedly very wild theory is that at some point Vesta sustained a hit similar in scope, though not in size, to what is theorized for the earth and its moon, a collision which turned both objects molten and either started Vesta spinning or increased its rate of spin. I think it was an equatorial hit. While Vesta was cooling but the surface was still semi molten the bands formed in a fashion not unlike clouds that form in the equatorial regions of the gas giants, because the equatorial regions were moving faster than the regions to the north and south. They retained the trough shape because the surface basically cooled that way. What happened to the object that struck Vesta? It’s scattered all over the Vestan surface. See the pattern of the impact craters? They look like objects struck a semi-molten surface that was rotating. Both Vesta and the object were too small to coalesce into a two-body system, like Earth and Luna, and the smaller object became an unstable ring around the dwarf planet, eventually coming apart and falling to Vesta’s surface, creating many of the impact craters we see on the surface.
Like I said, this is very wild and unfounded speculation. None-the-less it serves, at least for me, as a possible plausible explanation for those unique features and at least for now satisfies my curiosity about the troughs.
YMMV of course.
Post by: racshot65 on 10/01/2012 10:02 am
Quote
Dawn Completes Fifth Year of Flight
Dawn celebrated its fifth anniversary of spaceflight by continuing to thrust with its ion propulsion system on the long journey from Vesta to Ceres, just as it has most of the time since leaving the protoplanet earlier this month.
The probe has thrust for 1,060 days so far in the mission, or 58 percent of the time since launch. Its effective change in speed is more than 7.1 kilometers per second (16,000 miles per hour), well in excess of what any other spacecraft has achieved under its own power.
Thanks to the efficiency of the ion propulsion system, all this thrusting has consumed only 267 kilograms (587 pounds) of xenon propellant.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 10/01/2012 10:02 am
http://dawn.jpl.nasa.gov/mission/journal_09_27_12.asp
Post by: Star One on 10/01/2012 06:39 pm
QuoteDawn Completes Fifth Year of Flight
Dawn celebrated its fifth anniversary of spaceflight by continuing to thrust with its ion propulsion system on the long journey from Vesta to Ceres, just as it has most of the time since leaving the protoplanet earlier this month.
The probe has thrust for 1,060 days so far in the mission, or 58 percent of the time since launch. Its effective change in speed is more than 7.1 kilometers per second (16,000 miles per hour), well in excess of what any other spacecraft has achieved under its own power.
Thanks to the efficiency of the ion propulsion system, all this thrusting has consumed only 267 kilograms (587 pounds) of xenon propellant.
http://dawn.jpl.nasa.gov/mission/status.asp
Is there any chance it could have enough propellant left after it completes its Ceres mission to move onto another target?
Post by: Robotbeat on 10/03/2012 07:54 pm
There is, at least according to what I remember from the cruise stage...QuoteDawn Completes Fifth Year of Flight
Dawn celebrated its fifth anniversary of spaceflight by continuing to thrust with its ion propulsion system on the long journey from Vesta to Ceres, just as it has most of the time since leaving the protoplanet earlier this month.
The probe has thrust for 1,060 days so far in the mission, or 58 percent of the time since launch. Its effective change in speed is more than 7.1 kilometers per second (16,000 miles per hour), well in excess of what any other spacecraft has achieved under its own power.
Thanks to the efficiency of the ion propulsion system, all this thrusting has consumed only 267 kilograms (587 pounds) of xenon propellant.
http://dawn.jpl.nasa.gov/mission/status.asp
Is there any chance it could have enough propellant left after it completes its Ceres mission to move onto another target?
They want Dawn to leave Ceres to avoid contaminating it, which implies they are reserving some margin so they can guarantee that, which means that there should be enough propellant for at least some flybys of other targets. Whether there's enough funding for such an extended-extended mission is another question.
Post by: Star One on 10/04/2012 08:30 pm
There is, at least according to what I remember from the cruise stage...QuoteDawn Completes Fifth Year of Flight
Dawn celebrated its fifth anniversary of spaceflight by continuing to thrust with its ion propulsion system on the long journey from Vesta to Ceres, just as it has most of the time since leaving the protoplanet earlier this month.
The probe has thrust for 1,060 days so far in the mission, or 58 percent of the time since launch. Its effective change in speed is more than 7.1 kilometers per second (16,000 miles per hour), well in excess of what any other spacecraft has achieved under its own power.
Thanks to the efficiency of the ion propulsion system, all this thrusting has consumed only 267 kilograms (587 pounds) of xenon propellant.
http://dawn.jpl.nasa.gov/mission/status.asp
Is there any chance it could have enough propellant left after it completes its Ceres mission to move onto another target?
They want Dawn to leave Ceres to avoid contaminating it, which implies they are reserving some margin so they can guarantee that, which means that there should be enough propellant for at least some flybys of other targets. Whether there's enough funding for such an extended-extended mission is another question.
Thanks for that update, some sources I had read stated there wouldn't enough fuel left at end of the Ceres mission, so its good to hear a more positive response on the matter.
Post by: Robotbeat on 10/04/2012 08:51 pm
Mine is mostly just speculation, by the way, based on the fact that if they are allowing margin to get into and out of Ceres's gravity well, there almost surely will be some Xenon left over, though probably not enough to fully enter and leave low orbit around another body. That's why I speculated flyby.There is, at least according to what I remember from the cruise stage...QuoteDawn Completes Fifth Year of Flight
Dawn celebrated its fifth anniversary of spaceflight by continuing to thrust with its ion propulsion system on the long journey from Vesta to Ceres, just as it has most of the time since leaving the protoplanet earlier this month.
The probe has thrust for 1,060 days so far in the mission, or 58 percent of the time since launch. Its effective change in speed is more than 7.1 kilometers per second (16,000 miles per hour), well in excess of what any other spacecraft has achieved under its own power.
Thanks to the efficiency of the ion propulsion system, all this thrusting has consumed only 267 kilograms (587 pounds) of xenon propellant.
http://dawn.jpl.nasa.gov/mission/status.asp
Is there any chance it could have enough propellant left after it completes its Ceres mission to move onto another target?
They want Dawn to leave Ceres to avoid contaminating it, which implies they are reserving some margin so they can guarantee that, which means that there should be enough propellant for at least some flybys of other targets. Whether there's enough funding for such an extended-extended mission is another question.
Thanks for that update, some sources I had read stated there wouldn't enough fuel left at end of the Ceres mission, so its good to hear a more positive response on the matter.
Post by: racshot65 on 11/02/2012 10:48 pm
Quote
Dawn Continues Thrusting as it Begins Approaching the Sun
Dawn spent most of the past month continuing to reshape its orbit with its ion propulsion system. Although it is making good progress toward Ceres, which is farther from the sun, its course is now bringing it temporarily closer to the sun. It will not be this far from the sun again until May 2014. The latest Dawn Journal explains this enigmatic behavior.
Although most spacecraft coast most of the time, Dawn has now accumulated three years of ion thrust, and much more powered flight is ahead.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: racshot65 on 12/07/2012 09:40 pm
Quote
Dawn's Operating Profile Modified to Conserve Hydrazine Propellant
Dawn's powered flight to Ceres is continuing smoothly. Mission controllers have changed its routine to conserve the hydrazine propellant it will use in its exploration of that dwarf planet. The spacecraft interrupts ion thrusting to turn to point its main antenna less frequently now. In addition, when it does turn, it moves more slowly. The most recent Dawn Journal describes these changes and the motivation for them.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: stone on 12/13/2012 08:16 pm
Mine is mostly just speculation, by the way, based on the fact that if they are allowing margin to get into and out of Ceres's gravity well, there almost surely will be some Xenon left over, though probably not enough to fully enter and leave low orbit around another body. That's why I speculated flyby.There is, at least according to what I remember from the cruise stage...QuoteDawn Completes Fifth Year of Flight
Dawn celebrated its fifth anniversary of spaceflight by continuing to thrust with its ion propulsion system on the long journey from Vesta to Ceres, just as it has most of the time since leaving the protoplanet earlier this month.
The probe has thrust for 1,060 days so far in the mission, or 58 percent of the time since launch. Its effective change in speed is more than 7.1 kilometers per second (16,000 miles per hour), well in excess of what any other spacecraft has achieved under its own power.
Thanks to the efficiency of the ion propulsion system, all this thrusting has consumed only 267 kilograms (587 pounds) of xenon propellant.
http://dawn.jpl.nasa.gov/mission/status.asp
Is there any chance it could have enough propellant left after it completes its Ceres mission to move onto another target?
They want Dawn to leave Ceres to avoid contaminating it, which implies they are reserving some margin so they can guarantee that, which means that there should be enough propellant for at least some flybys of other targets. Whether there's enough funding for such an extended-extended mission is another question.
Thanks for that update, some sources I had read stated there wouldn't enough fuel left at end of the Ceres mission, so its good to hear a more positive response on the matter.
A talk at the Göttingen University on scientist from the Framing Camera said that they aim for one or another fly-by strongly depending on the the exact course and goal and the results from Ceres.
Post by: clongton on 12/13/2012 11:16 pm
Post by: robertross on 12/13/2012 11:21 pm
While I was excited and engaged while Dawn studied Vesta, Ceres is the destination that holds the most interest for me. I really want to know how much water is there. Dawn will tell us.
I just hope that they didn't expend too much propellant at Vesta that could hinder full study at Ceres. It should be okay, but one never knows for certain. I like margin.
Post by: cleonard on 12/14/2012 12:16 am
While I was excited and engaged while Dawn studied Vesta, Ceres is the destination that holds the most interest for me. I really want to know how much water is there. Dawn will tell us.
I just hope that they didn't expend too much propellant at Vesta that could hinder full study at Ceres. It should be okay, but one never knows for certain. I like margin.
The real problem is the worn out reaction wheel bearings. When the next one fails it will reduce the science return as they will have no choice but to use the thrusters to point the spacecraft. That's why the remaining propellant is so critical now.
Post by: stone on 12/14/2012 08:03 am
While I was excited and engaged while Dawn studied Vesta, Ceres is the destination that holds the most interest for me. I really want to know how much water is there. Dawn will tell us.
At the AGU there was a talk about Vesta and one about Ceres. Although nearly nothing is known about Ceres it sounded very cool. With an ocean and salt and gypsum layers. Compared to that Vesta is a very normal asteroid.
Post by: gospacex on 12/14/2012 11:46 am
The real problem is the worn out reaction wheel bearings.
Can't reaction wheels be designed to run without mechanical contact? A magnetic bearings of some sort? After all, the craft is in near-0g, not in the Earth's 1g field.
Post by: Hungry4info3 on 12/14/2012 12:31 pm
Can't reaction wheels be designed to run without mechanical contact? A magnetic bearings of some sort?Doesn't that defeat the purpose of a reaction wheel?
Post by: gospacex on 12/14/2012 12:47 pm
Can't reaction wheels be designed to run without mechanical contact? A magnetic bearings of some sort?Doesn't that defeat the purpose of a reaction wheel?
It does not. Momentum transfer between the rotating wheel and the rest of spacecraft does not require physical contact.
Post by: Nomadd on 12/14/2012 12:48 pm
Why would it? It doesn't matter if you push on something directly or with a magnet.Can't reaction wheels be designed to run without mechanical contact? A magnetic bearings of some sort?Doesn't that defeat the purpose of a reaction wheel?
Post by: racshot65 on 01/04/2013 06:18 pm
Quote
Dawn Completes a Spectacular Year and Continues toward Ceres
Dawn ended its extraordinarily successful 2012 by smoothly continuing to thrust with its ion propulsion system to its 2015 rendezvous with dwarf planet Ceres. In December, as Earth and Dawn followed their independent orbits, they were at their closest distance in more than a year. As the spacecraft continues its interplanetary adventure, you can locate its position in the sky using the moon as a guide on Jan. 21.
http://dawn.jpl.nasa.gov/mission/status.asp
Post by: spectre9 on 07/14/2013 06:57 am
http://dawnblog.jpl.nasa.gov/2013/07/12/a-dawn-mission-scientists-story/#more-41
I liked it :)
Post by: ClaytonBirchenough on 07/14/2013 02:51 pm
A new blog has been started for Dawn.
http://dawnblog.jpl.nasa.gov/2013/07/12/a-dawn-mission-scientists-story/#more-41
I liked it :)
Nice. Why start a blog now though?
Post by: spectre9 on 07/14/2013 03:00 pm
A new blog has been started for Dawn.
http://dawnblog.jpl.nasa.gov/2013/07/12/a-dawn-mission-scientists-story/#more-41
I liked it :)
Nice. Why start a blog now though?
I'm guessing it's because David Blewitt is excited about the mission and wants to engage in public outreach.
I think that's a great thing.
I thought his blog was interesting and helped me understand some of the preliminary results from the study of Vesta without being overly complicated.
Job well done.
Post by: ClaytonBirchenough on 07/14/2013 03:03 pm
I'm guessing it's because David Blewitt is excited about the mission and wants to engage in public outreach.
I think that's a great thing.
I thought his blog was interesting and helped me understand some of the preliminary results from the study of Vesta without being overly complicated.
Job well done.
Agreed. Nice little summary of things too.
Post by: catdlr on 09/27/2013 03:52 pm
Dawn Reality-Checks Telescope Studies of Asteroids
Science Benefits From Diverse Landing Area of NASA Mars Rover
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-293&cid=release_2013-293
Tantalized by images from NASA's Hubble Space Telescope and ground-based data, scientists thought the giant asteroid Vesta deserved a closer look. They got a chance to do that in 2011 and 2012, when NASA's Dawn spacecraft orbited the giant asteroid, and they were able to check earlier conclusions. A new study involving Dawn's observations during that time period demonstrates how this relationship works with Hubble and ground-based telescopes to clarify our understanding of a solar system object.
"Since the vast majority of asteroids can only be studied remotely by ground-based and space-based facilities, confirming the accuracy of such observations using in-situ measurements is important to our exploration of the solar system," said Vishnu Reddy, the lead author of a paper published recently in the journal Icarus. Reddy is based at the Planetary Science Institute in Tucson, Ariz., and the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany.
In the paper, Reddy and other members of Dawn's framing camera team describe how up-close observations of Vesta have confirmed and provided new insights into more than 200 years of Earth-based observations.
Vesta, the second most massive asteroid in the main asteroid belt, differs from most garden-variety asteroids in having a crust, mantle and core like our Earth. Early ground-based observations of Vesta, which was discovered in 1807, showed that Vesta's color and surface composition changed as it rotated around its axis. Astronomers using NASA's Infrared Telescope Facility at Mauna Kea in Hawaii saw distinct compositional units. It wasn't until Dawn arrived at Vesta that scientists determined the fine details and the exact distribution of these color variations, and the difference in composition between these regions.
"A generation of scientific questions framed on the basis of lower-resolution data have been resolved by visiting Vesta with Dawn," said Dawn Principal Investigator Christopher Russell, who is based at the University of California, Los Angeles. "We chose to go to Vesta because the ground-based telescopes and, later, Hubble told us it was an interesting place. That was true, but we needed Dawn to discern the mineral distribution and history of Vesta's surface. We now know how these data sets tie together and complement each other. This will help us in our telescopic studies of other members of our solar system."
One particularly useful comparison for future work on asteroids or other solar system objects involves comparing Dawn's framing camera data to data from Hubble. With Hubble, astronomers first saw the giant impact basin near the south pole of Vesta and also identified numerous bright and dark features on Vesta that correspond to different compositional units. It wasn't until Dawn's framing camera provided high-resolution views of Vesta that scientists were able to see the detailed contours of the giant impact basin that came to be called Rheasilvia and saw how bright the brightest materials were and how dark the dark materials were. Dawn's observations also showed that there was an older, overlapping giant impact basin under Rheasilvia. The bright materials appear to be pristine rocks native to Vesta, while the carbon-rich dark material appears to have been brought to Vesta from afar.
"When Dawn got to Vesta, it showed us how accurate Hubble's data were about Vesta," said Planetary Science Institute research scientist Jian-Yang Li, the Dawn participating scientist who mapped out the surface of Vesta using Hubble data. "And it also showed us how Vesta was so much more interesting up-close."
Other paper co-authors include Robert Gaskell and Lucille Le Corre of the Planetary Science Institute.
Launched in 2007, Dawn orbited Vesta for more than a year, departing in September 2012. Dawn is now on its way to the dwarf planet Ceres and will arrive there in early 2015.
The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. The University of California, Los Angeles, is responsible for overall Dawn mission science. The Dawn framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany; with significant contributions by DLR German Aerospace Center Institute of Planetary Research, Berlin; and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The framing camera project is funded by the Max Planck Society, DLR and NASA.
Jia-Rui Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
[email protected]
Alan Fischer 520-382-0411
Planetary Science Institute, Tucson, Ariz.
[email protected]
- end -
Post by: clongton on 09/27/2013 07:47 pm
It makes me hopeful that much of what we think we know about Ceres will also prove to be correct, such as how much water is there.
Again - thank you.
Post by: jacqmans on 12/17/2013 08:31 am
December 16, 2013
Some beauty is revealed only at a second glance. When viewed with the human eye, the giant asteroid Vesta, which was the object of scrutiny by the Dawn spacecraft from 2011 to 2012, is quite unspectacular color-wise. Vesta looks grayish, pitted by a variety of large and small craters.
http://www.jpl.nasa.gov/news/news.php?release=2013-367&utm_source=iContact&utm_medium=email&utm_campaign=NASAJPL&utm_content=dawn20131216
Post by: clongton on 08/04/2014 12:57 pm
2. What is the arrival date at Ceres?
Post by: Jeff Lerner on 08/04/2014 01:11 pm
http://www.planetary.org/blogs/guest-blogs/marc-rayman/20140801-dawn-journal-not-so-quiet-cruise.html
Post by: SaxtonHale on 08/04/2014 03:19 pm
http://dawn.jpl.nasa.gov/mission/journal.asp
(They get cross-posted to the Planetary Society blog as well, but here is the full archive)
But to answer your question, it will get to Ceres in late March 2015
Post by: Blackstar on 08/04/2014 03:39 pm
http://www.lpi.usra.edu/sbag/meetings/jul2014/agenda.shtml
Post by: metaphor on 08/05/2014 03:23 am
Post by: clongton on 08/05/2014 10:23 pm
Post by: baldusi on 08/06/2014 12:37 am
Post by: metaphor on 08/06/2014 02:08 pm
This isn't a race. Both celestial objects are very worthy of closeup examination. Too bad that New Horizons won't enter Pluto orbit for that examination. But the instruments aboard her are very sophisticated and will download a wealth of data to us. What will actually be found at Pluto remains a mystery but it's for sure that taking advantage of whatever is there is a very long time away, while Ceres, if the science proves what is suspected, might be the key to opening the entire solar system in the short term.
Yes. I'm excited about both of them. Ceres and Pluto are two of the last large unexplored bodies in the solar system. It's an interesting coincidence that the first close-up probes to the only two former planets and current dwarf planets in the solar system will arrive at their targets within a few months of each other.
However, it does seem that New Horizons is getting the lion's share of the press, even though Dawn is arguably just as important and maybe even more so in some respects.
Post by: Ben the Space Brit on 09/16/2014 04:52 pm
I still wonder if the next step after Mars isn't Ceres.
The more I hear about Ceres, the more excited I get about it. It's more like a miniature-size Galilean or major Saturnian Moon than an asteroid. I wouldn't be surprised if it had a water vapour atmosphere like Enceladus (which is actually about half the size of Ceres) and maybe a very weak magnetic field, similar to that of Ganymede or Mercury.
Ceres is a hard target with a big delta-V budget but it might be a worthwhile mission, especially if the DSL can stop off on some other main belt targets on the way out and back.
Post by: Nomadd on 09/24/2014 08:34 pm
http://www.spaceflightnow.com/news/n1409/18dawn/#.VCMqJsmCeCg
Post by: kfsorensen on 10/29/2014 04:35 pm
Post by: Zed_Noir on 10/29/2014 07:26 pm
Does anyone know if Dawn has had an intentional thruster shutdown (coast) or has had some type of engine failure? The online images appear to show that it has changed orientation and isn't thrusting. Since hydrazine is so precious on Dawn, any unnecessary reorientation of the spacecraft might represent diminished mission life at Ceres.IRRC the spacecraft have periodic thruster shutdowns to facilitate communication for spacecraft status updates.
Post by: kfsorensen on 11/01/2014 01:10 am
Post by: clongton on 11/01/2014 10:24 am
New Dawn update has been posted. Arrival at Ceres scheduled for March 6.
This is the mission I have been waiting for. I am far more interested in Ceres than any other dwarf planet because of its potential to actually be a water world. If if turns out to be true it could well be the single thing that opens the solar system to us.
Post by: MATTBLAK on 11/01/2014 10:40 am
Post by: Star One on 11/01/2014 10:56 am
Post by: Nomadd on 11/01/2014 11:26 am
Ceres is interesting because it comes from out by Pluto's neck of the woods so next year we will get to study two Kupier belt objects in the same period of time.Not sure where you got that idea. Ceres has nothing to do with the Kuiper belt. It was probably formed pretty much where it is.
Post by: Star One on 11/01/2014 01:33 pm
Ceres is interesting because it comes from out by Pluto's neck of the woods so next year we will get to study two Kupier belt objects in the same period of time.Not sure where you got that idea. Ceres has nothing to do with the Kuiper belt. It was probably formed pretty much where it is.
I have my doubts about that theory and prefer the idea that it's a Kuiper Belt Object that's moved into the inner solar system.
Quote
An alternative theory proposes that Ceres formed in the Kuiper belt and later migrated to the asteroid belt.[77] Another possible protoplanet, Vesta, is less than half the size of Ceres; it suffered a major impact after solidifying, losing ~1% of its mass.[78]
http://en.m.wikipedia.org/wiki/Ceres_(dwarf_planet)
Post by: notsorandom on 11/01/2014 03:45 pm
Thankfully in just a few months after Dawn arrives at Ceres New Horizons will be taking our first look at the Pluto system. Along with the investigations of the Jovian and Saturnian moons I suspect that we will be able to do a pretty good job of figuring out how Ceres fits in with the rest of the neighborhood.Ceres is interesting because it comes from out by Pluto's neck of the woods so next year we will get to study two Kupier belt objects in the same period of time.Not sure where you got that idea. Ceres has nothing to do with the Kuiper belt. It was probably formed pretty much where it is.
I have my doubts about that theory and prefer the idea that it's a Kuiper Belt Object that's moved into the inner solar system.QuoteAn alternative theory proposes that Ceres formed in the Kuiper belt and later migrated to the asteroid belt.[77] Another possible protoplanet, Vesta, is less than half the size of Ceres; it suffered a major impact after solidifying, losing ~1% of its mass.[78]
http://en.m.wikipedia.org/wiki/Ceres_(dwarf_planet)
Post by: Star One on 11/01/2014 04:38 pm
Thankfully in just a few months after Dawn arrives at Ceres New Horizons will be taking our first look at the Pluto system. Along with the investigations of the Jovian and Saturnian moons I suspect that we will be able to do a pretty good job of figuring out how Ceres fits in with the rest of the neighborhood.Ceres is interesting because it comes from out by Pluto's neck of the woods so next year we will get to study two Kupier belt objects in the same period of time.Not sure where you got that idea. Ceres has nothing to do with the Kuiper belt. It was probably formed pretty much where it is.
I have my doubts about that theory and prefer the idea that it's a Kuiper Belt Object that's moved into the inner solar system.QuoteAn alternative theory proposes that Ceres formed in the Kuiper belt and later migrated to the asteroid belt.[77] Another possible protoplanet, Vesta, is less than half the size of Ceres; it suffered a major impact after solidifying, losing ~1% of its mass.[78]
http://en.m.wikipedia.org/wiki/Ceres_(dwarf_planet)
Very true it would be interesting if it was a Kupier belt object for comparative analysis if nothing else.
Post by: Vultur on 11/01/2014 07:35 pm
Post by: Ben the Space Brit on 11/02/2014 09:06 am
Of course, this model depends on Ceres being an Inner or Middle Solar System object. If it is an Outer Solar System object like Triton and Pluto, the probability of it having enough metals to generate a magnetic field is unlikely.
@Star One
Is that Kuiper Belt origin theory related to the theory that the Late Heavy Bombardment, the evidence of which we see on The Moon and Mercury, was caused by Jupiter, Saturn, Uranus and Neptune all changing orbital radii about 4Bya?
Post by: the_other_Doug on 11/02/2014 03:05 pm
My personal theory is the Ceres might be a bit like a miniature version of Ganymede and Callisto - Rocky/metallic core, slushy saltwater mantle and an icy crust with a rarified atmosphere of water vapour replenished from the occasional rare fissure that opens up in the crust when Jupiter slides past. I wouldn't even be surprised if it as a very weak magnetic field generated in the mantle.
Of course, this model depends on Ceres being an Inner or Middle Solar System object. If it is an Outer Solar System object like Triton and Pluto, the probability of it having enough metals to generate a magnetic field is unlikely.
All the more reason to mourn the fact that Dawn's magnetometer was de-scoped from the mission, during the period when some people were trying to kill Dawn altogether. (I sometimes think that they mandated the removal of the magnetometer so they could later say that, without a magnetometer, the mission wouldn't return enough science to be worth flying... sigh...)
We could have learned a lot from the magnetic field strength (if any) at Ceres and even Vesta. As it stands, we may not see another probe out to Ceres in my lifetime, so I, for one, may never know if it has a magnetic field or not...
-Doug (With my shield, not yet upon it)
Post by: clongton on 11/02/2014 07:54 pm
All the more reason to mourn the fact that Dawn's magnetometer was de-scoped from the mission, during the period when some people were trying to kill Dawn altogether.
There will always be those simple minded people who are against funding anything except their personal pet projects. Unfortunately some of them have learned how to scream very loudly and make a huge scene. These people remind me of a child who is a spoiled brat. And like any spoiled brat they need to be spanked, not coddled to.
Post by: Nomadd on 11/02/2014 10:58 pm
Post by: metaphor on 11/03/2014 02:22 pm
My personal theory is the Ceres might be a bit like a miniature version of Ganymede and Callisto - Rocky/metallic core, slushy saltwater mantle and an icy crust with a rarified atmosphere of water vapour replenished from the occasional rare fissure that opens up in the crust when Jupiter slides past. I wouldn't even be surprised if it as a very weak magnetic field generated in the mantle.
Jupiter is really far from Ceres and wouldn't affect it in any significant way physically (although it does affect Ceres's orbit). Tidal forces are proportional to m/r^3, and Jupiter only gets about as close to Ceres as the Sun does. So Jupiter's tidal effect on Ceres would only be 1/1000 of the solar-induced tides (which are themselves only about 1/15 the strength of the Earth's solar-induced tides).
However, it's possible that Ceres's elliptical orbit would cause some changes in its surface as it receives more or less heat from the Sun over the course of an orbital period.
We'll know a lot more in just a few months.
Post by: notsorandom on 11/03/2014 02:29 pm
I know the possibility can't be dismissed, but there's still a lot of guesswork as to the nature of Kuiper belt dwarfs. Charon is only a little bigger than Ceres, so that comparison should be interesting. Is there any real reason to suspect Ceres' origin is different than the larger gas giant moons?The idea that Ceres could be a KBO is based on some models of the Solar System's formation which predict a roughly 1 in 10 chance. I'd speculate that the GRaND instrument aboard Dawn which measures the composition of Ceres is going to be what is most useful in characterizing Ceres' relationship and origin. The Galilean satellites are all at least 100 times larger than Ceres. The rest of the Jovian satellites are significantly smaller. Also there is a different amount of solar irradiance due to the closer orbit to the sun. The dynamics under which Ceres formed would be different because of its size. The crust would have cooled quicker than the Galilean moons yet Ceres did end up round unlike the rest. So a direct comparison is a bit trickier. As you point out though Charon is pretty close in mass and size so it should be a very good example of Ceres looks like if it were a KBO.
Post by: Star One on 11/03/2014 03:48 pm
My personal theory is the Ceres might be a bit like a miniature version of Ganymede and Callisto - Rocky/metallic core, slushy saltwater mantle and an icy crust with a rarified atmosphere of water vapour replenished from the occasional rare fissure that opens up in the crust when Jupiter slides past. I wouldn't even be surprised if it as a very weak magnetic field generated in the mantle.
Of course, this model depends on Ceres being an Inner or Middle Solar System object. If it is an Outer Solar System object like Triton and Pluto, the probability of it having enough metals to generate a magnetic field is unlikely.
@Star One
Is that Kuiper Belt origin theory related to the theory that the Late Heavy Bombardment, the evidence of which we see on The Moon and Mercury, was caused by Jupiter, Saturn, Uranus and Neptune all changing orbital radii about 4Bya?
What about the idea that Ceres was pushed out of the Kuiper belt by the influence of a passing star far back in time it's believed stars move some comets out of the Oort Cloud.
Post by: as58 on 11/03/2014 04:01 pm
What about the idea that Ceres was pushed out of the Kuiper belt by the influence of a passing star far back in time it's believed stars move some comets out of the Oort Cloud.
How would the orbit circularise afterwards?
Post by: Star One on 11/03/2014 04:26 pm
What about the idea that Ceres was pushed out of the Kuiper belt by the influence of a passing star far back in time it's believed stars move some comets out of the Oort Cloud.
How would the orbit circularise afterwards?
It's inward fall could have been arrested by another body, for a start we surmise that Jupiter and Saturn weren't always in their current positions.
Post by: jebbo on 11/03/2014 07:27 pm
Very roughly, Jupiter migrated inward through the initial disc and "tacked" somewhere around 1.5AU when Saturn had caught up with it and was in a 3:2 resonance that changed the disc torques such that they both migrated outwards until the disc had dissipated ... and the migration of J+S is the origin of the LHB.
This left an inner disc from which the inner planets formed.
A decent overview is given here http://arxiv.org/abs/1409.6340
On a later perturbation and circularisation, it feels unlikely - after disc dissipation you are left with tidal effects (and I don't think there is enough time) or planet-planet scattering which seems unlikely given the low eccentricity.
--- Tony
Post by: Robotbeat on 11/06/2014 12:48 am
Post by: Star One on 11/06/2014 06:33 am
Not sure if it was mentioned here, yet (haven't seen it), but Dawn is going to stay at Ceres indefinitely. At the end of the mission after studying Ceres, Dawn will be put in a long-term-stable orbit.
I wonder how long its instruments will be able to keep producing data.
Post by: kevin-rf on 11/06/2014 12:13 pm
Not sure if it was mentioned here, yet (haven't seen it), but Dawn is going to stay at Ceres indefinitely. At the end of the mission after studying Ceres, Dawn will be put in a long-term-stable orbit.
I wonder how long its instruments will be able to keep producing data.
Wouldn't it be more of an issue of how long will it have propellant for attitude control (desaturation of gyro's) so com, solar, and instruments can be pointed correctly?
Post by: Ben the Space Brit on 11/06/2014 12:20 pm
Not sure if it was mentioned here, yet (haven't seen it), but Dawn is going to stay at Ceres indefinitely. At the end of the mission after studying Ceres, Dawn will be put in a long-term-stable orbit.
I wonder how long its instruments will be able to keep producing data.
Wouldn't it be more of an issue of how long will it have propellant for attitude control (desaturation of gyro's) so com, solar, and instruments can be pointed correctly?
The advantage of solar arrays is that power generation isn't a problem, it's propellent exhaustion and degeneration of navigation and other components. I read somewhere that the Voyagers will fail a lot earlier than demanded by their power supply because the power distribution components are breaking down due to extreme age. So, the same problem could eventually afflict Dawn.
Of course, the key issue is how long NASA are willing to fund the mission. If I were at JPL, I would urge SMD, strongly, to keep Dawn operational for one Ceresian year, minimum. This would maximise the data return of the changing Ceresian environment with time.
Post by: Nomadd on 11/06/2014 01:53 pm
Post by: kfsorensen on 11/06/2014 07:41 pm
If I were at JPL, I would urge SMD, strongly, to keep Dawn operational for one Ceresian year, minimum. This would maximise the data return of the changing Ceresian environment with time.
The limiting factor to Dawn's time at Ceres will likely be their hydrazine inventory. If they look like they have enough for a mission extension I am fairly certain that SMD will grant them one. Until then, there's not much point in asking.
Post by: kfsorensen on 11/07/2014 03:20 pm
Post by: ncb1397 on 11/07/2014 04:23 pm
The relative position and velocity of Dawn to Ceres made a big (discontinuous) jump this morning, at least as listed on the mission's webpage. Makes me wonder if they were way off in where they thought the spacecraft was relative to the asteroid.
(http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Ceres_optimized.jpg/200px-Ceres_optimized.jpg)
Does that look like an asteroid to you?
Post by: MarsInMyLifetime on 11/07/2014 04:37 pm
The relative position and velocity of Dawn to Ceres made a big (discontinuous) jump this morning, at least as listed on the mission's webpage....Can you provide a link to the previous/current data? The ion engine is not capable of a big jump in a short time frame, so I wonder if this is a calibration delta rather than an actual operational change.
Post by: pagheca on 11/07/2014 05:08 pm
The relative position and velocity of Dawn to Ceres made a big (discontinuous) jump this morning, at least as listed on the mission's webpage. Makes me wonder if they were way off in where they thought the spacecraft was relative to the asteroid.
can you give a link to the source, please? Couldn't find this.
Post by: kfsorensen on 11/07/2014 06:05 pm
Today it has Dawn about 1.75 million km from Ceres. Yesterday if memory serves they were something like 2.4 million km from Ceres. It makes me think that they took an opnav pic of Ceres and it wasn't where they thought it was. It also looks like they've suspended thrusting.
Post by: joncz on 11/07/2014 08:10 pm
http://dawnblog.jpl.nasa.gov/2014/10/31/dawn-journal-october-31/ (http://dawnblog.jpl.nasa.gov/2014/10/31/dawn-journal-october-31/)
Post by: kfsorensen on 11/07/2014 10:03 pm
Post by: ugordan on 11/07/2014 10:19 pm
Post by: Quagga on 11/07/2014 10:23 pm
Post by: Ben the Space Brit on 11/12/2014 04:58 pm
[edit]
Fixed link tag
Post by: kfsorensen on 12/03/2014 07:03 pm
Post by: clongton on 12/03/2014 08:59 pm
The spacecraft was supposed to take some calibration pictures of Ceres on December 1st, 2 days ago.
Does anyone have an update on how that went? The pictures won't reveal anything new about Ceres, it's still too distant, but the pixel-width is perfect for the calibration.
Really looking forward to this mission! :)
Post by: ugordan on 12/05/2014 09:10 pm
The resolution of this image does not yet exceed the best views of Ceres, which were obtained by the Hubble Space Telescope (see PIA10235). Nonetheless, Ceres' spherical shape is clearly revealed here. Sunlight illuminates the dwarf planet from the right, leaving a sliver of the surface in shadow at left.
http://dawn.jpl.nasa.gov/feature_stories/Dawn_snaps_image_Ceres.asp
Post by: clongton on 12/05/2014 09:16 pm
Post by: Nomadd on 12/06/2014 03:04 am
Post by: Mongo62 on 12/06/2014 02:16 pm
That looks to be about 9 pixels in width. Is that correct? How did the calibration go?
From the most recent blog entry (http://dawnblog.jpl.nasa.gov/2014/11/28/dawn-journal-november-28/):
Quote
On Dec. 1, Ceres will be about nine pixels in diameter, nearly perfect for this calibration.
So the image of Ceres is just the size it was expected to be.
Post by: metaphor on 12/07/2014 06:26 am
I'm having trouble with the numbers. They say that Dawn will have better resolution photos than Hubble by 1/26, but Hubble is 20 times as good right now and Dawn will only have covered half? the remaining distance by then.
Dawn will have covered more than half the remaining distance by then. It's essentially slowing down to meet Ceres with constant deceleration, so its distance to the target is approximately proportional to the square of the time until capture. Unlike New Horizons, which is performing a high-speed flyby, so its distance to the target is proportional to the time until flyby.
So at half the time until capture, Dawn should have covered about 3/4 of the remaining distance. Which means that its pictures of Ceres should be about 36 pixels across by then.
Post by: kfsorensen on 12/20/2014 12:54 pm
Post by: plutogno on 12/20/2014 01:58 pm
Dawn is approximately two lunar radii from Ceres now.
only 3400 km?!? are you sure? you probably mean two lunar orbit radii...
Post by: Eerie on 12/20/2014 02:00 pm
Dawn is approximately two lunar radii from Ceres now.
Two lunar radii is 3474 km.
Maybe you mean two lunar orbit radii?
Post by: catdlr on 12/30/2014 10:45 pm
http://science.nasa.gov/science-news/science-at-nasa/2014/30dec_dawn/
Quote
Dec 30, 2014: NASA's Dawn spacecraft has entered an approach phase in which it will continue to close in on Ceres, a Texas-sized dwarf planet never before visited by a spacecraft. Dawn launched in 2007 and is scheduled to enter Ceres orbit in March 2015.
https://www.youtube.com/watch?v=5OFgJwdZxRc
Post by: kfsorensen on 12/31/2014 03:36 am
Post by: redliox on 12/31/2014 07:24 pm
It'll be interesting seeing what Ceres is like. It could help define the definition of 'dwarf planet' (I still hate that term), especially since Ceres is on the smaller end of the scale (since being spherical is the minimum requirement). Despite being substantially closer to the Sun, the fact Ceres has a huge amount of water in its composition gives it kinship to Pluto and Eris. With encounters with both bodies this new year, we'll be able to make comparisons and better judgment calls about this class of bodies.
Post by: hop on 12/31/2014 08:57 pm
I wonder how heavily the reaction wheel problem will affect the mapping of Ceres. Dawn's now down to 2 of them. I'm sure they've already compensated for this, but can't make the probe's job any easier.AFAIK, they expect to be able to get all their nominal science even if the remaining wheels fail. They have been doing everything they can to conserve hydrazine since they recognized the problem, and have adjusted the Ceres plan to minimize consumption as well. The bummer is losing the possibility of an extended mission to visit another target.
Post by: mcgyver on 01/07/2015 12:43 pm
(http://dawnblog.jpl.nasa.gov/wp-content/uploads/2014/12/Gateway_Ceres.jpg)
Let's see how it evolves in next months. :) (Arrival planned on march 6th).
Post by: cd-slam on 01/08/2015 08:09 am
Let's see how it evolves in next months. :) (Arrival planned on march 6th).Next pictures are due on January 13. I'm salivating in anticipation. :)
Post by: Ben the Space Brit on 01/09/2015 11:24 am
At about 1/3 the distance too! So, it should be a very interesting shot indeed. Would it be better resolution than the best Hubble image?Let's see how it evolves in next months. :) (Arrival planned on march 6th).
Next pictures are due on January 13. I'm salivating in anticipation. :)
Post by: Star One on 01/12/2015 05:43 pm
http://www.spacedaily.com/m/reports/Dawn_of_a_strange_new_world_999.html
Post by: Ben the Space Brit on 01/12/2015 10:11 pm
I'm expecting Dawn to start to speed up soon as it falls into Ceres's gravity well.
Post by: Nilof on 01/13/2015 12:49 pm
Post by: cd-slam on 01/13/2015 05:42 pm
Post by: ugordan on 01/13/2015 06:02 pm
According to Dawn's official Twitter feed @NASA_Dawn, now we're going to have to wait until "week of 1/26" for the next image of Ceres.
Huh? That's for Hubble-resolution or better.
They still haven't released the image from the 13th yet. It's supposed to be released on 15th or 16th and will be 26 pixels across.
Post by: kevin-rf on 01/13/2015 06:10 pm
Post by: cd-slam on 01/14/2015 03:44 am
According to Dawn's official Twitter feed @NASA_Dawn, now we're going to have to wait until "week of 1/26" for the next image of Ceres.
Huh? That's for Hubble-resolution or better.
They still haven't released the image from the 13th yet. It's supposed to be released on 15th or 16th and will be 26 pixels across.
Ah thanks, you are right, I misread the tweet. Not so long to wait.
Post by: Ben the Space Brit on 01/14/2015 12:29 pm
They still haven't released the image from the 13th yet. It's supposed to be released on 15th or 16th and will be 26 pixels across.
Image processing and giving the science team the chance to review the data before it's sent out into the wild, I expect.
Post by: K-P on 01/14/2015 02:48 pm
(*puts tin foil hat on and runs away*)
;)
Post by: Robotbeat on 01/14/2015 03:02 pm
Blame the European scientists, they're much stingier with releasing scientific data (image data) than the Americans. That's also why we didn't get very many color images from Rosetta, relying mostly on the engineering cameras. They're all concerned about getting "dibs" on any results.They still haven't released the image from the 13th yet. It's supposed to be released on 15th or 16th and will be 26 pixels across.
Image processing and giving the science team the chance to review the data before it's sent out into the wild, I expect.
Post by: kato on 01/14/2015 05:03 pm
That's also why we didn't get very many color images from Rosetta67P/C-G has mostly one color: Pitch-black. And OSIRIS, which is what you're referring to, doesn't do color at all in fact. Other than through green, blue and orange filters anyway, which is how there's a couple heavily postprocessed pseudocolor images - by taking multiple photos from multiple positions with the various filters, wrapping them on a 3D shape model and "blending" the colors, and then taking a virtual photo of this.
As for the current Dawn imaging campaign, according to MPS it's considered to be "for optical navigation purposes" and the images hence directly delivered to NASA JPL Flight Dynamics as they were downloaded.
Post by: pagheca on 01/14/2015 05:17 pm
Blame the European scientists, they're much stingier with releasing scientific data (image data) than the Americans. That's also why we didn't get very many color images from Rosetta, relying mostly on the engineering cameras. They're all concerned about getting "dibs" on any results.
It's not the European or American scientist to be (that) different from each other. The problem is with the contract that ESA and NASA let them sign. In one case, data rights by the PIs are much more relaxed than in the other.
As soon as ESA will understand the importance of outreach (as NASA did) things will be the same. It's really the way ESA understand its role that MUST change. I had many harsh discussions about that with people working there.
At the end of the day, the real difference is the way European Institutions intend their role. But this is a too long story to be discussed here...
Post by: ThereIWas3 on 01/14/2015 05:59 pm
Academic institutions are also very protective of their copyrights on this material, even for research that was paid for by taxes. Very very (https://en.wikipedia.org/wiki/Aaron_Swartz) protective.
Post by: pitcapuozzo on 01/15/2015 07:34 am
So? What happened to the image taken on the 13th that should have been released today/tomorrow? I'm confused.
Post by: pagheca on 01/15/2015 09:22 am
So? What happened to the image taken on the 13th that should have been released today/tomorrow? I'm confused.
I don't know if this is the case in this particular case, but if the Instrument PI didn't give permission of disclosure they can't release it.
Post by: pitcapuozzo on 01/15/2015 09:55 am
So? What happened to the image taken on the 13th that should have been released today/tomorrow? I'm confused.
I don't know if this is the case in this particular case, but if the Instrument PI didn't give permission of disclosure they can't release it.
Yea, I guess that's what's happening, but it sucks :P Thanks!
Post by: Ben the Space Brit on 01/15/2015 01:30 pm
Post by: kevin-rf on 01/15/2015 02:04 pm
Post by: the_other_Doug on 01/15/2015 07:37 pm
Relax, the images will be released soon. In time, be time...
Post by: kch on 01/15/2015 07:51 pm
Then it must be aliens ;) Aliens that are 26 pixels wide ...
Hope it's not those darn Sycorax again! ;D
Post by: pitcapuozzo on 01/16/2015 05:11 am
Post by: yg1968 on 01/19/2015 03:35 pm
http://www.nasa.gov/jpl/dawn-delivers-new-image-of-ceres/#.VL0rmnvAuVB
https://twitter.com/NASA_Dawn/status/557207353326465024
Post by: redliox on 01/19/2015 05:19 pm
Sweet animation of Ceres. You can definitely see the bright spot in north, but in addition there seems to be the impression of a crater near the south pole and two mare-like objects south of the equator. Too early to guess what any of these could be, but finally Dawn is close enough to match the Hubble! Only New Horizon matching this feat at Pluto could be any more exciting!
Post by: Star One on 01/19/2015 05:34 pm
Post by: kevin-rf on 01/19/2015 05:47 pm
Post by: jebbo on 01/19/2015 06:52 pm
--- Tony
See http://home.comcast.net/~eliws/ceres/files/KeckIIAOCeres.ppt
Post by: Ben the Space Brit on 01/19/2015 08:16 pm
Yeah, I'm sticking with my theory that Ceres will turn out to be a native mid-Solar System body and will share many geological and structural features with the Galileans, even though it is much smaller.
Damn! This and New Horizons? I haven't been this excited since Voyager 2 reached Uranus back in '86 (which was the first major robotic exploration event that I was old enough to really understand).
Post by: Star One on 01/19/2015 08:30 pm
You mean the bright spot isn't a bright spot? Now I am really confuse ;)It's a parked flying saucer.;)
Post by: kevin-rf on 01/20/2015 12:01 am
It's a trap!You mean the bright spot isn't a bright spot? Now I am really confuse ;)It's a parked flying saucer.;)
Post by: MarsInMyLifetime on 01/20/2015 01:06 am
Post by: mr. mark on 01/20/2015 03:34 am
Post by: Ben the Space Brit on 01/20/2015 09:31 am
I am way more interested in the two dark areas in the just below the equator. Definiately has peaked my interest.
I'm pretty sure that's the dark feature 'Piazzi', identified from the Keck and Hubble images. At the moment, it's tentatively classified as an impact feature but it's so elongated that I wouldn't be surprised if it turns out to be called Mare Piazzi.
I'm still sticking with the CWS being a recent major impact feature like Copernicus on Luna.
Post by: Ben the Space Brit on 01/20/2015 02:17 pm
Synthesized color image of Ceres:
The general colouration makes me think of some Galileo enhanced-colour images of Europa; another indicator that the two worldlets are similar in many ways?
Post by: SimonFD on 01/20/2015 02:47 pm
It's a trap!You mean the bright spot isn't a bright spot? Now I am really confuse ;)It's a parked flying saucer.;)
I was waiting for "That's no moon......" ;)
Post by: clongton on 01/20/2015 05:00 pm
Post by: baldusi on 01/20/2015 05:17 pm
I've been waiting for a long time for Dawn to reach Ceres. To me it is the most interesting place in the solar system. From what we know (?) it is likely to be a huge water source and if that pans out it could change the entire way we explore the system. Just think: a potentially limitless fuel supply that is not at the bottom of a huge gravity well.But a 10.6deg inclined plane to the ecliptic. for example, Mercury is 7deg and is quite an issue.
Post by: mfck on 01/20/2015 05:25 pm
I've been waiting for a long time for Dawn to reach Ceres. To me it is the most interesting place in the solar system. From what we know (?) it is likely to be a huge water source and if that pans out it could change the entire way we explore the system. Just think: a potentially limitless fuel supply that is not at the bottom of a huge gravity well.But a 10.6deg inclined plane to the ecliptic. for example, Mercury is 7deg and is quite an issue.
How much deltaV for Ceres to go to 0° inclination? [Edit: ~3km/s ?]
What fraction of Ceres mass would need to be expelled for that maneuver? [Edit: in reasonable timeframe, say 10 years]
Post by: metaphor on 01/20/2015 05:46 pm
I've been waiting for a long time for Dawn to reach Ceres. To me it is the most interesting place in the solar system. From what we know (?) it is likely to be a huge water source and if that pans out it could change the entire way we explore the system. Just think: a potentially limitless fuel supply that is not at the bottom of a huge gravity well.But a 10.6deg inclined plane to the ecliptic. for example, Mercury is 7deg and is quite an issue.
How much deltaV for Ceres to go to 0° inclination?
What fraction of Ceres mass would need to be expelled for that maneuver?
That would be 3.3 km/s of delta-v, or 50% of Ceres's mass expelled if using hydrolox engines.
It's actually not that easy to reach Ceres from Earth due to the lack of a deep gravity well or atmosphere to slow down in.
Post by: mfck on 01/20/2015 05:49 pm
Ah.. Thanks, edited my post before I saw yoursI've been waiting for a long time for Dawn to reach Ceres. To me it is the most interesting place in the solar system. From what we know (?) it is likely to be a huge water source and if that pans out it could change the entire way we explore the system. Just think: a potentially limitless fuel supply that is not at the bottom of a huge gravity well.But a 10.6deg inclined plane to the ecliptic. for example, Mercury is 7deg and is quite an issue.
How much deltaV for Ceres to go to 0° inclination?
What fraction of Ceres mass would need to be expelled for that maneuver?
That would be 3.3 km/s of delta-v, or 50% of Ceres's mass expelled if using hydrolox engines.
It's actually not that easy to reach Ceres from Earth due to the lack of a deep gravity well or atmosphere to slow down in.
Well, i think the point being in reaching from Ceres into the System (sending fuel in), not going to Ceres to refuel.
Post by: yokem55 on 01/20/2015 06:00 pm
Edit:
Granted, this just moves the inclination change to the end of the flight instead of the beginning, but you would have a relatively light craft arriving at Ceres propulsivly and you could aerocapture at Earth your heavy payload of water.
Post by: Nilof on 01/20/2015 06:05 pm
Chemical propulsion is not a very useful technology for getting to Ceres. The slight edge it has for Mars transfers due to short burn times disappears entirely for more distant targets, where SEP easily beats chemical in both transfer time and payload fraction.
Post by: metaphor on 01/22/2015 03:54 pm
Stabilized version of Ceres rotation gif:
(http://i.imgur.com/mcO7mY6.gif)
Post by: Ben the Space Brit on 01/22/2015 04:20 pm
Post by: NovaSilisko on 01/22/2015 04:28 pm
I'm trying to work out the sun angle on the animated gif. The image is definitely a oval flattened along the a bottom left to top right axis; is the terminator the upper or lower edge?
Lower. The upper edge is the limb, and much brighter. You can see some distinct terrain relief on the lower edge as well, consistent with that being the terminator.
Post by: Ben the Space Brit on 01/22/2015 04:38 pm
I'm trying to work out the sun angle on the animated gif. The image is definitely a oval flattened along the a bottom left to top right axis; is the terminator the upper or lower edge?
Lower. The upper edge is the limb, and much brighter. You can see some distinct terrain relief on the lower edge as well, consistent with that being the terminator.
*Squints*
Okay... so, if I'm interpreting this correctly, Dawn is coming up from 'below' Ceres's orbital plane but is almost directly in between the Sun and the planetoid. The north rotational pole is out of sight beyond the upper limb and the south rotational pole is on the middle of the terminator. That puts the CWS either in the northern tropics, the equator or somewhere in between.
Post by: clongton on 01/22/2015 08:49 pm
With low-thrust SEP it's closer to 10 km/s, and much better payload fractions, but that undercuts the advantage of using the water as fuel in the first place.
Not if the payload is water headed for either martian or earth orbit.
Post by: yg1968 on 01/23/2015 04:02 pm
http://www.space.com/28336-mysterious-white-spot-on-ceres.html?adbid=558663015923339265&adbpl=tw&adbpr=15431856&cmpid=514648_20150123_39279697
Quote
"Yes, we can confirm that it is something on Ceres that reflects more sunlight, but what that is remains a mystery," Marc Rayman, mission director and chief engineer for the Dawn mission, told Space.com in an email.
Post by: notsorandom on 01/23/2015 05:28 pm
Article about the White spot on Ceres:The white spot was known before Dawn imaged it. There are several Hubble images which showed it. I suspect that the animation of the latest Dawn images in particular has brought attention to it. It stands out pretty well in that. I can't wait to find out what it is.
http://www.space.com/28336-mysterious-white-spot-on-ceres.html?adbid=558663015923339265&adbpl=tw&adbpr=15431856&cmpid=514648_20150123_39279697Quote"Yes, we can confirm that it is something on Ceres that reflects more sunlight, but what that is remains a mystery," Marc Rayman, mission director and chief engineer for the Dawn mission, told Space.com in an email.
Post by: kfsorensen on 01/23/2015 06:32 pm
Post by: Oberon_Command on 01/23/2015 06:37 pm
Post by: clongton on 01/23/2015 06:58 pm
Does anyone have information on an extended mission profile?
Post by: Ben the Space Brit on 01/23/2015 07:08 pm
Forgive me if I missed it, but do we know when we can expect the next image of Ceres from Dawn?
Image to be taken 26/1/2015 with processing meaning that it will take a few days before it's ready to be released to the public.
Post by: the_other_Doug on 01/25/2015 02:15 am
And, BTW, they've generally been releasing images about a week after they're taken, give or take a day or two.
Post by: Ben the Space Brit on 01/25/2015 09:02 am
And, BTW, they've generally been releasing images about a week after they're taken, give or take a day or two.
The program's Twitter feed (https://twitter.com/NASA_Dawn/status/555962029773578240) has already stated that transmission to Earth and data processing always takes a couple of days.
Another interesting thing from that Twitter feed: The science team consider it unlikely that Ceres has a natural satellite. However, they are aware that a sufficiently small and dark body could have been missed by all observations to date. They are therefore going to work in an imaging sweep of the area around Ceres in an attempt to see if there are any moons.
Post by: Moe Grills on 01/25/2015 05:23 pm
I'm betting the bright spot is a very fresh impact crater that has excavated a lot of fresh water ice. But I'm open to whatever it is we see in a couple of months.\
Let's make assumptions now and get egg on our faces in a couple of months. ;)
Alternative list for the bright spot being are:
1) A vast field of whitish beach sand.
2) A huge chalk quarry.
3) Some aliens spilled huge quantities of milk at one location.
4) Some mad artist had a huge supply of white paint on Ceres.
5) It's not really white, but a pale amber color.
LMAO.
Post by: clongton on 01/25/2015 09:54 pm
Chris - a little help here?
Post by: kevin-rf on 01/25/2015 11:14 pm
Post by: tp1024 on 01/25/2015 11:37 pm
I think it would be spot on if Chris found a spot for a party thread.
Well, I don't think there is spotty coverage of party thread spots. But regardless of the spots on Ceres, a permanent party spot for spotty spaceparties in the exploration of particularly interesting spots in the solar system would be appreciated. ;D
Post by: Star One on 01/26/2015 06:29 am
I think it would be spot on if Chris found a spot for a party thread.
Well, I don't think there is spotty coverage of party thread spots. But regardless of the spots on Ceres, a permanent party spot for spotty spaceparties in the exploration of particularly interesting spots in the solar system would be appreciated. ;D
Let's hope we don't get in a spot of bother over all this.
Post by: yokem55 on 01/27/2015 04:50 am
The primary mission schedule shows start-of-mission in March 2015 and end-of-mission in July 2015.I think this will depend on the performance of the space craft. If they lose another reaction wheel, then the mission will probably be wrapped up soon after as they'll be burning fuel for orientation needs. If the craft is performing well, then an extended mission to observe Ceres over the course of a season or two is probably in order. And if there is anything really exciting found, as in "OMG, redirect the Europa Clipper funds into a Ceres lander stat!", exciting, then substantial effort will go into using Dawn to scope out potential landing sites and an extended mission will be funded for that.
Does anyone have information on an extended mission profile?
Post by: Ben the Space Brit on 01/27/2015 11:03 am
Post by: ugordan on 01/27/2015 11:22 am
An image accompanying this article may give an early glimpse of the resolution: http://tucson.com/news/blogs/scientific-bent/ceres-may-reveal-the-secrets-of-planets/article_7f0d164b-39a8-5216-9d64-920cd46de206.html
Post by: ugordan on 01/27/2015 01:25 pm
Post by: Ben the Space Brit on 01/27/2015 01:50 pm
[edit]
Just to clarify my theory: Callisto's surface is mostly water ice that has been darkened to near black by aeons of exposure to solar radiation. The only break are large impact craters that have dug through to the lighter ice underneath. I'm wondering if that's the case with Ceres.
Why so few recent large impactors? Well, remember that Jupiter is practically the solar system's vacuum cleaner, sucking in various comets, small- and moderate-sized asteroids and the like. A large number of these would inevitably impact on the moons, especially the two largest which have significant gravity wells of their own and sufficiently non-dynamic surfaces that craters last more than a few million years.
Ceres, on the other hand, is on the outer edge of the Main Belt where, ironically (The Empire Strikes Back notwithstanding), large impactors and even medium-sized ones have been quite rare in the last three billion years. Given that Ceres is a small target and that its orbital region isn't that much more heavily populated by potential impactors than ours, it is unsurprising that there are fewer large, white impact craters.
FWIW, the newest images show three other possible excavation-to-white-ice craters but much smaller. More images from closer may tell us more.
Post by: RotoSequence on 01/27/2015 04:43 pm
Post by: Star One on 01/27/2015 07:15 pm
Post by: kevin-rf on 01/27/2015 07:26 pm
What ever this is, it is quite bright, Let the mindless speculation about Asteroids with Frickin Lasers begin in 3,. 2,. 1...
I will now argue, that since they have not yet resolved the feature, they will not be able to figure out how bright it really is until they resolve it and figure out it's area. 1 pixel, supper shiny ice surface?
Post by: Blackstar on 01/27/2015 07:34 pm
The primary mission schedule shows start-of-mission in March 2015 and end-of-mission in July 2015.I think this will depend on the performance of the space craft. If they lose another reaction wheel, then the mission will probably be wrapped up soon after as they'll be burning fuel for orientation needs. If the craft is performing well, then an extended mission to observe Ceres over the course of a season or two is probably in order. And if there is anything really exciting found, as in "OMG, redirect the Europa Clipper funds into a Ceres lander stat!", exciting, then substantial effort will go into using Dawn to scope out potential landing sites and an extended mission will be funded for that.
Does anyone have information on an extended mission profile?
Marc Rayman, the mission PI, was on The Space Show yesterday and I asked him about landing. He said it is not possible. Ceres' gravity is too high and the spacecraft would impact at too high a velocity. In addition, they have planetary protection requirements that forbid landing on Ceres. You can listen to the episode here:
http://thespaceshow.com/detail.asp?q=2401
Essentially, the spacecraft will die in its orbit.
Post by: Nilof on 01/27/2015 08:17 pm
It has been pointed out by Emily Lakdawalla that in the latest images, the bright spot is almost one pixel wide...
What ever this is, it is quite bright, Let the mindless speculation about Asteroids with Frickin Lasers begin in 3,. 2,. 1...
I will now argue, that since they have not yet resolved the feature, they will not be able to figure out how bright it really is until they resolve it and figure out it's area. 1 pixel, supper shiny ice surface?
Clearly it must be a bunch of Freeman Dyson's sunflowers. (http://www.newscientist.com/article/dn17078-could-flowers-bloom-on-icy-moon-europa.html#.VMf_1i7pwU9) ;)
Post by: Zed_Noir on 01/28/2015 12:08 am
The primary mission schedule shows start-of-mission in March 2015 and end-of-mission in July 2015.I think this will depend on the performance of the space craft. If they lose another reaction wheel, then the mission will probably be wrapped up soon after as they'll be burning fuel for orientation needs. If the craft is performing well, then an extended mission to observe Ceres over the course of a season or two is probably in order. And if there is anything really exciting found, as in "OMG, redirect the Europa Clipper funds into a Ceres lander stat!", exciting, then substantial effort will go into using Dawn to scope out potential landing sites and an extended mission will be funded for that.
Does anyone have information on an extended mission profile?
Marc Rayman, the mission PI, was on The Space Show yesterday and I asked him about landing. He said it is not possible. Ceres' gravity is too high and the spacecraft would impact at too high a velocity. In addition, they have planetary protection requirements that forbid landing on Ceres. You can listen to the episode here:
http://thespaceshow.com/detail.asp?q=2401
Essentially, the spacecraft will die in its orbit.
Maybe a monobloc impacter might have bene useful. Something along the lines of long rod penetrators in anti-tank cannon rounds. Basically a machined Tungsten rod. The impact should kick up interesting things for the orbiter to look at. Unless the planetary protection requirement nixed that idea.
Post by: Blackstar on 01/28/2015 02:34 am
Post by: redliox on 01/28/2015 04:10 am
Dark and lumpy; makes me think of Callisto a little.
[edit]
Just to clarify my theory: Callisto's surface is mostly water ice that has been darkened to near black by aeons of exposure to solar radiation. The only break are large impact craters that have dug through to the lighter ice underneath. I'm wondering if that's the case with Ceres.
I think I can concur with that. It is too early to say whether your opinion regarding large impactors is valid or not, but only because we can't easily identify what even is a crater on Ceres for the moment. If I had to guess, I'd be willing to bet Ceres turns out to be a mix of Callisto, Triton, and Luna. Given it's location in the asteroid belt, and likelihood it's native, it surely has both ice and rock - maybe like Pluto but less exotic forms of ice. I doubt it will be as exciting as the Galilean moons of Jupiter but it should give us a few surprises.
Post by: Orbiter on 01/28/2015 01:14 pm
Post by: Ben the Space Brit on 01/28/2015 01:30 pm
Ceres looks quite a bit like Umbriel, one of the moons of Uranus. They're also somewhat similar in size, with Umbriel being larger.
To me, this all fits into my viewpoint that Ceres is a typical mid-sized mid-solar system terrestrial body - a rocky core with a salt-water ice/slush mantle and dark, near-black water ice + hydrocarbon contaminants icy crust. I'm pretty sure that, by July this year, we'll have it in the same type category as the smaller moons of Saturn and Uranus and a dwarf version of Ganymede and Callisto.
Post by: mcgyver on 01/28/2015 05:19 pm
Ceres looks quite a bit like Umbriel, one of the moons of Uranus. They're also somewhat similar in size, with Umbriel being larger.A source for this amazing iamage?
Are we going to find out that Ceres is "more a planet than Pluto"? ???
Post by: yg1968 on 01/28/2015 05:20 pm
Ceres looks quite a bit like Umbriel, one of the moons of Uranus. They're also somewhat similar in size, with Umbriel being larger.A source for this amazing iamage?
Are we going to find out that Ceres is "more a planet than Pluto"? ???
Just to be clear, that is an image of Umbriel (not Ceres).
Post by: Blackstar on 01/28/2015 07:44 pm
A source for this amazing iamage?
It's probably from one of the several spacecraft that have flown past Uranus.
Post by: the_other_Doug on 01/28/2015 08:13 pm
Post by: ugordan on 01/28/2015 08:16 pm
A source for this amazing iamage?
It's probably from one of the several spacecraft that have flown past Uranus.
My sarcasm detector just had a RUD.
Post by: Blackstar on 01/28/2015 09:20 pm
There actually has only been one spacecraft that has ever flown past Uranus -- Voyager 2, in 1986. Others have flown as far, and farther, away from the Sun as Uranus, but unfortunately they and the planet have never been remotely near each other at the time...
Can you provide a citation that there's only been one spacecraft that flew past Uranus?
Post by: yokem55 on 01/28/2015 09:30 pm
Can you provide a citation that there's only been one spacecraft that flew past Uranus?
From the easiest source on the interwebs (http://en.wikipedia.org/wiki/Uranus#Exploration):
Quote
In 1986, NASA's Voyager 2 interplanetary probe encountered Uranus. This flyby remains the only investigation of Uranus carried out from a short distance and no other visits are planned.
Post by: NovaSilisko on 01/28/2015 09:31 pm
Maybe we need a 'Why So Cere-ous' party thread by now :P
Post by: Orbiter on 01/28/2015 11:01 pm
Voyager 2 is the only spacecraft to visit the planet Uranus. Several attempts at further exploration of Uranus (along with Neptune) have been proposed, all of which are either notional, cancelled, or were rejected as concepts.
Post by: Ben the Space Brit on 01/29/2015 09:00 am
Post by: clongton on 01/29/2015 03:50 pm
Post by: kfsorensen on 01/29/2015 09:54 pm
Post by: RotoSequence on 02/03/2015 11:49 pm
Post by: HammerD on 02/04/2015 04:47 pm
Post by: Ben the Space Brit on 02/05/2015 11:15 am
It was scheduled for Feb 3rd. So hopefully any time now we will see a new image released.
Confirmed by official Twitter feed (https://twitter.com/NASA_Dawn/status/563108989412859904).
Post by: ugordan on 02/05/2015 01:41 pm
Post by: RotoSequence on 02/05/2015 02:30 pm
http://dawn.jpl.nasa.gov/feature_stories/Dawn_getting_closer_views.asp
Post by: yg1968 on 02/05/2015 02:32 pm
https://twitter.com/NASA_Dawn/status/563354247601729538
http://photojournal.jpl.nasa.gov/catalog/PIA19179
Post by: Ben the Space Brit on 02/05/2015 02:40 pm
CWS is more and more like a major recent impact crater, IMHO.
Post by: Quagga on 02/05/2015 02:42 pm
Post by: RotoSequence on 02/05/2015 02:43 pm
CWS is more and more like a major recent impact crater, IMHO.
Maybe it's just me, but looking at the big animation, I'm almost starting to think that the big Ceres white spot (holy smokes, there are multiple Ceres white spots!) might actually be a mountain.
Post by: HammerD on 02/05/2015 02:59 pm
Anyway, a bit interesting the white spots...maybe some different type of material exposed from asteroid impacts.
Will be nice to see the sharper images in March/April.
Post by: robertross on 02/05/2015 03:35 pm
JPL Delivers!
http://dawn.jpl.nasa.gov/feature_stories/Dawn_getting_closer_views.asp
I knew there would be a death star out there somewhere! (j/k) :)
Post by: Ben the Space Brit on 02/05/2015 04:05 pm
CWS is more and more like a major recent impact crater, IMHO.
Maybe it's just me, but looking at the big animation, I'm almost starting to think that the big Ceres white spot (holy smokes, there are multiple Ceres white spots!) might actually be a mountain.
The resolution is still insufficient to be certain but, if anything, it looks to me like it's punched right into the middle of a mountain range/ridge or possibly the edge of an older impact basin (much like the Bay of Rainbows on Luna).
Post by: Blackstar on 02/05/2015 06:00 pm
Post by: mike robel on 02/05/2015 06:43 pm
JPL Delivers!
http://dawn.jpl.nasa.gov/feature_stories/Dawn_getting_closer_views.asp
I knew there would be a death star out there somewhere! (j/k) :)
It's HOLLOW! :) :) :) :)
Post by: redliox on 02/05/2015 06:52 pm
When I checked the Dawn Journal's chart for position, the best views prior to orbit will come near the end of February. Due to orbital mechanics Dawn with then loop out during March and from April onward the views get increasingly better.
Post by: clongton on 02/07/2015 12:26 am
Post by: KelvinZero on 02/08/2015 09:35 am
When will we see some true color images?
Post by: Blackstar on 02/08/2015 03:04 pm
Don't be disappointed if that white spot is just some exposed metastable allotrope of carbon ;)
When will we see some true color images?
I think it is a laser cannon port.
Post by: redliox on 02/08/2015 06:18 pm
Don't be disappointed if that white spot is just some exposed metastable allotrope of carbon ;)
When will we see some true color images?
I think it is a laser cannon port.
That last comment brought this to mind ;)
(http://stream1.gifsoup.com/view/41528/death-star-shoop-da-whoop-o.gif)
*somewhere in JPL* It's a trap!
Post by: Ben the Space Brit on 02/08/2015 07:03 pm
Don't be disappointed if that white spot is just some exposed metastable allotrope of carbon ;)
Can't diamond be described in those terms?
Post by: Blackstar on 02/08/2015 07:27 pm
Post by: Bob Shaw on 02/08/2015 07:47 pm
The bottom of the bright spot seems to be quite flat. :o
You can't tell anything at that sun angle - no shadows to speak of from anything. Wait until it approaches the terminator.
Post by: Quagga on 02/09/2015 08:42 pm
You can't tell anything at that sun angle - no shadows to speak of from anything. Wait until it approaches the terminator.
You're probably right. It was actually the lack of discernible features that made me think that. I'm just too impatient. :-\
Post by: kfsorensen on 02/10/2015 05:16 pm
Post by: Bob Shaw on 02/10/2015 10:07 pm
Post by: Ben the Space Brit on 02/11/2015 01:29 pm
Dawn will reverse course soon,
I think that the term 'pass initial periceres' might be be more accurate. As I understand it, the probe has already been caught by Ceres's gravity and will loop back towards the planet after heading out some distance. It will continue thrusting all the time to bring down its' apiceres until it's in a circular orbit.
Post by: RotoSequence on 02/11/2015 04:55 pm
Quote
This animated gif is composed of several images that NASA's Dawn spacecraft took on approach to Ceres on Feb. 4, 2015 at a distance of about 90,000 miles (145,000 kilometers) from the dwarf planet. This series of images is the sharpest to date, at a resolution of 8.5 miles (14 kilometers) per pixel.
Dawn's mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Virginia, designed and built the spacecraft. JPL is managed for NASA by the California Institute of Technology in Pasadena. The framing cameras were provided by the Max Planck Institute for Solar System Research, Gottingen, Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The visible and infrared mapping spectrometer was provided by the Italian Space Agency and the Italian National Institute for Astrophysics, built by Selex ES, and is managed and operated by the Italian Institute for Space Astrophysics and Planetology, Rome. The gamma ray and neutron detector was built by Los Alamos National Laboratory, New Mexico, and is operated by the Planetary Science Institute, Tucson, Arizona.
https://twitter.com/NASA_Dawn/status/565563291351941121
Quote
Quote@NASA_Dawn @DLR_en @NASA How white are the "white spots"--actually whitish, or just less dark gray?@That_MarcC @DLR_en @NASA Good question. Less dark gray is a better description, def not as bright as ice on an Earth mountaintop.
Post by: pagheca on 02/11/2015 05:35 pm
http://dawn.jpl.nasa.gov/multimedia/Ceres_on_approach.asp
This animated gif is composed of several images that NASA's Dawn spacecraft took on approach to Ceres on Feb. 4, 2015 at a distance of about 90,000 miles (145,000 kilometers) from the dwarf planet. This series of images is the sharpest to date, at a resolution of 8.5 miles (14 kilometers) per pixel.
Are those images in the visible or NIR?
Has brightness scale been enhanced?
Post by: hop on 02/12/2015 02:03 am
Are those images in the visible or NIR?The earlier images were with the clear filter. I would guess the same is true for these.
Quote
Has brightness scale been enhanced?IMO, it's a safe bet they were contrast stretched.
Post by: pagheca on 02/12/2015 08:23 am
IMO, it's a safe bet they were contrast stretched.
Thanks. In this case is clear the "white spot" can really be everything.
It would also be interesting to see the scene for once as the human eye would see it. Without exposure time and filter info it would be difficult to change brightness accurately.
Post by: Ben the Space Brit on 02/12/2015 09:20 am
IMO, it's a safe bet they were contrast stretched.
Thanks. In this case is clear the "white spot" can really be everything.
It would also be interesting to see the scene for once as the human eye would see it. Without exposure time and filter info it would be difficult to change brightness accurately.
I think that the one thing that we can say about the Ceres White Spot with certainty is that it is the most reflective point on the planet across a range of wavelengths. On some images, it comes across as over-exposed which is a key indicator of this. The contrast stretching, needed to reveal other features on the otherwise dark surface makes the Spot very, very bright.
Any explanation for it would have to include this fact.
Post by: Robotbeat on 02/12/2015 12:05 pm
Post by: pagheca on 02/12/2015 01:13 pm
But consider that it appeared at least twice the albedo of the rest of that planet (which is .09, so almost black) even in the really blurry Hubble pics, but the newer pics show that all that brightness is pretty much confined to a still very small spot. I did a quick calculation, and that implies a spot albedo of at least .5. And of course the albedo will be underestimated until high resolution images are available.
Mark Sykes, PSI Director, see a 10% (more?).
also other (http://www.psi.edu/about/staff) sources talk about 10% more:
Quote
The spots are areas of slightly increased reflectiveness, representing barely a 9% higher albedo than the surrounding surface.
How did you do your calculations?
Post by: Robotbeat on 02/12/2015 10:55 pm
I did them based on the images, assuming a linear stretch of the graphs. Also, 9% higher albedo than 9% could mean either 9.9% (i.e 10%) or 18%. :) But yeah, it's hard to do any such calculations if they used a wacky stretch. If anyone has the raw Hubble images or knows where to find them, I'd be happy to see!But consider that it appeared at least twice the albedo of the rest of that planet (which is .09, so almost black) even in the really blurry Hubble pics, but the newer pics show that all that brightness is pretty much confined to a still very small spot. I did a quick calculation, and that implies a spot albedo of at least .5. And of course the albedo will be underestimated until high resolution images are available.
Mark Sykes, PSI Director, see a 10% (more?).
also other (http://www.psi.edu/about/staff) sources talk about 10% more:QuoteThe spots are areas of slightly increased reflectiveness, representing barely a 9% higher albedo than the surrounding surface.
How did you do your calculations?
The rest I did based on the relative size of the spot in the Hubble images versus the newer images, a technique which doesn't really rely on the color scale being done a certain way (other than the initial albedo assumption).
Post by: RotoSequence on 02/12/2015 11:23 pm
Post by: LLivingLarge on 02/13/2015 05:34 am
DSS 63
Post by: Ben the Space Brit on 02/13/2015 11:54 am
[Edit]
Dawn is now ~47k miles or 75.5k kilometres from Ceres. That's, what? Twice the radial size of geostationary orbit? I do hope that they take an an image sequence as they pass periceres and get as much data from the other instruments as possible.
Post by: RotoSequence on 02/13/2015 05:57 pm
*assuming a constant 125.01 kilobits per second over the past ~11 hours.
Post by: kfsorensen on 02/13/2015 09:43 pm
Post by: MATTBLAK on 02/13/2015 09:54 pm
Post by: LLivingLarge on 02/13/2015 10:03 pm
Post by: Robotbeat on 02/14/2015 12:55 am
I wonder what the per-megabyte costs are for the "DSN data plan"?Depends more on time (on the big dishes) than on data volume. An hour receiving data from Voyager is probably about the same, say, as an hour receiving data from Cassini, even though the volumes of data are orders of magnitude different.
Post by: Blackstar on 02/15/2015 08:45 pm
Post by: LouScheffer on 02/15/2015 10:42 pm
Should be easy to figure out. JPL proves an "Aperture Fee tool" to estimate DSN costs. You can get it here: http://deepspace.jpl.nasa.gov/advmiss/proposalpreparation/# . For the "small" 34 meter antenna, it's $1057 per hour. At 125.01 kb/sec, it's 53.6 MB/hour. So the per-megabyte costs, assuming they were using the small antenna, is about $1057/53.6 = $19.07 per megabyte. If they required a big antenna to get that data rates, then it's 4x that.Looks like Dawn wrapped up its transmission a few minutes ago, with approximately 650 megabytes of data sent back to Earth*. :)
*assuming a constant 125.01 kilobits per second over the past ~11 hours.
I wonder what the per-megabyte costs are for the "DSN data plan"?
Of course, like any state-of-the-art wireless carriers, there are plenty of extra, non-avoidable fees - mostly extra hours with no data, for setup, teardown, calibration, etc.
Post by: baldusi on 02/16/2015 01:02 am
Sort of a non sequitur, but I was at a workshop on Friday where somebody mentioned that WFIRST will produce 5-gigabyte images. So we're getting to a point with space telescopes where the amount of data per image is going to be overwhelming.It doesn't quite belongs here, but it might be reasonable to set up an LCT service for SEL2.
Post by: LouScheffer on 02/16/2015 01:36 pm
Sort of a non sequitur, but I was at a workshop on Friday where somebody mentioned that WFIRST will produce 5-gigabyte images. So we're getting to a point with space telescopes where the amount of data per image is going to be overwhelming.The ground based telescopes are even worse. For the LSST, which has a 3.2 gigapixel camera, a large mirror, and fast slewing speed: "Current estimates indicate LSST will create 12.8 gigabytes (GB) of data every 39 seconds" ( http://www.lsst.org/lsst/public/tour_software ).
So the main problem with space telescopes will be getting the data to the ground. If you can do that, the processing pipelines being designed for modern ground-based telescopes should be able to cope with the resulting data rates. This is particularly true since one of the main advantages of space telescopes is to take really long exposures, since there is no background light to interfere.
Post by: Blackstar on 02/16/2015 02:14 pm
Although you have a good point that infrastructure built for ground telescopes is going to be bigger than what the space systems will require, I'd point out that it's going to be different infrastructure--it won't be the same computers handling this stuff. The space data is going to come down along its own pipe and require its own systems. NASA isn't going to just send the images to the LSST computers.
We've wandered off topic, but I'm sure we'll return when we get the next (low-res) Dawn image in a day or two.
Post by: baldusi on 02/16/2015 05:53 pm
Post by: Blackstar on 02/16/2015 06:31 pm
I understand that for some projects, they used to transfer data by mailing hard drives (in the 2000s).
Still do. I know somebody who works on a space telescope and to send some of their large data sets it is easier and faster to simply send some hard drives by FedEx.
Post by: Robotbeat on 02/16/2015 08:35 pm
I used to design/build SANs with 10s of gigabits/s throughput, and that was years ago targeting small/medium businesses. They were pretty cheap, nowadays would be even cheaper.
Post by: Quagga on 02/17/2015 02:38 pm
Post by: Malderi on 02/17/2015 04:17 pm
Post by: NovaSilisko on 02/17/2015 04:26 pm
Those pictures look... distinctly non-spherical. Is Ceres really that shape, or is that a trick of the light/perspective?
Looks like a bit of both, to me. At first I thought it was just the light angle but even taking that into account, it looks a bit egg-shaped.
Post by: Quagga on 02/17/2015 04:41 pm
Post by: clongton on 02/17/2015 09:54 pm
Post by: the_other_Doug on 02/17/2015 10:51 pm
If you rotate it such that the side on the right is on the bottom, you can see the oblateness is such that the sphere is a little squashed at the poles. Considering how fast Ceres spins, it appears this is due to a slightly plastic body (the "soft ice" conjecture) being affected by its spin, with the centripetal force being a higher proportion of force to gravity than it is for other rounded bodies in the solar system. Again, telescopic examinations, while not too useful in showing us surface features, have been very helpful in determining how oblate Ceres is.
However, like many of y'all, it certainly looks to me like Ceres is out-of-round not just in the polar oblateness, but also that it seems to bulge out visibly, especially in the northern hemisphere. It's hard to reconcile that with a body that's supposed to have been warm enough to create "soft" ice and that was once warm enough to become differentiated. It almost looks like an exaggerated version of the Tharsis plateau on Mars, where a whole lot of lava got piled up onto about one-quarter of the planet's surface. Hard to say how far that metaphor can be stretched at Ceres, since hot-rock volcanism has likely not been a strong sculpting force at Ceres.
The latest opnavs give us some real tantalizing clues to landforms underlying the heavily cratered surface, and the possibility that some of the darker albedo terrain might occupy the centers of old impact basins. As we get closer, these details will resolve themselves -- literally! -- and will shed a lot of light on the current questions.
Remember, though, that as our knowledge increases, we will just be trading one set of questions for a new, more complex set. That process really never stops.
Exhilarating, ain't it?
Post by: kato on 02/18/2015 05:29 am
So the main problem with space telescopes will be getting the data to the ground. If you can do that, the processing pipelines being designed for modern ground-based telescopes should be able to cope with the resulting data rates.Gaia produces several GBit/s data (i.e. 10+ TB per day), and already preprocesses with a learning algorithm in space before streaming about 16 GB per day over to Earth.
Post by: Ben the Space Brit on 02/18/2015 10:16 am
Also, remember that Ceres is quite a small object. A major impact event could have seriously deformed the structure of the object, much as has happened to Vesta. IIRC, Mercury has had an impact large and powerful enough (the Caloris impactor) that the opposite hemisphere has a set of mountains at the precise antipode. That may be something similar to what we've seen here. The associated southern polar impact basin may be out of sight on the night side.
[edit]
New theory on the White Spots - We know that Ceres has a tenuous water vapour 'atmosphere'. What if the white spots are fresh frost deposits around the vents that maintain it? Sort of like the multicolour sulphur deposits around Io's volcanoes?
Post by: kevin-rf on 02/18/2015 02:05 pm
Post by: Star One on 02/18/2015 02:51 pm
Next set of images to be taken on the 20/2.
Post by: kfsorensen on 02/18/2015 11:54 pm
Post by: clongton on 02/19/2015 12:31 am
Post by: Blackstar on 02/19/2015 01:11 am
What is the date that the spacecraft is supposed to enter Ceres orbit?
March 6.
Post by: KelvinZero on 02/19/2015 11:11 am
Dr. Paul Schenk on Unmannedspaceflight (http://www.unmannedspaceflight.com/index.php?s=&showtopic=7960&view=findpost&p=218122)
I think I read somewhere there was a chance of oceans (under the ice) though I dont know how. I assumed Europa's ocean was all about the tidal heating.
Post by: K-P on 02/19/2015 11:38 am
Yep, I can't get it to fit into a circle.
Try the same with Saturn.
Even with the big boys it isn't so simple...
Post by: Ben the Space Brit on 02/20/2015 02:12 pm
Post by: gospacex on 02/20/2015 02:25 pm
If you rotate it such that the side on the right is on the bottom, you can see the oblateness is such that the sphere is a little squashed at the poles. Considering how fast Ceres spins, it appears this is due to a slightly plastic body (the "soft ice" conjecture) being affected by its spin, with the centripetal force being a higher proportion of force to gravity than it is for other rounded bodies in the solar system.
A fast rotating body does not need to be plastic to become oblate. It rotates with this angular velocity for billions of years. On these timescales, even seemingly rock-solid material will deform.
Post by: Moe Grills on 02/21/2015 05:04 pm
I assume that other mission parameters, such as an initial orbital altitude of 2400km for the first science survey phase will remain the same.
Too bad there is no magnetometer on this mission.
Post by: Bob Shaw on 02/22/2015 12:25 am
Are we now predisposed to look at Ceres as a gas giant moon analogue, and will both (either) of these alter the way we interpret the images? Clearly Ceres is a dwarf planet, but it is the only one which is almost in the inner Solar System, and has much more in common with Ganymede than Sedna.
I'm curious in part due to being able to remember the paradigm shifts between Mariner Mars 1969 and Mariner 9; I still have a much-treasured Mars globe based on 1969 flyby data which is wonderfully wrong, yet almost right.
Post by: KelvinZero on 02/22/2015 12:50 am
Pre-Dawn, there were interpretations of Ceres as a mini-Mars, with ice caps, river valleys and clay deposits; things have moved on, I'm sure.I don't think I ever saw an interpretation like that. I always expected a cratered ball, a bit lumpier than most due to it's smallish size. Possibly something at the poles since it must get very cold there. I was hoping for some pretty surprises like highly distinctive stains caused by contributions from radically different types of asteroids.. something that would make it immediately distinctive from any other world, like the red spot of jupiter or the rings of saturn or the cracked surface of europa or the mares of the moon's near side. I still don't really know what color it is or has.
Post by: Bob Shaw on 02/22/2015 05:18 pm
Pre-Dawn, there were interpretations of Ceres as a mini-Mars, with ice caps, river valleys and clay deposits; things have moved on, I'm sure.I don't think I ever saw an interpretation like that. I always expected a cratered ball, a bit lumpier than most due to it's smallish size. Possibly something at the poles since it must get very cold there. I was hoping for some pretty surprises like highly distinctive stains caused by contributions from radically different types of asteroids.. something that would make it immediately distinctive from any other world, like the red spot of jupiter or the rings of saturn or the cracked surface of europa or the mares of the moon's near side. I still don't really know what color it is or has.
I think I saw the mini-Mars description on the original Dawn website, pre-cancellation.
As for colour, the darn thing is pretty black according to the commentary on the early images. No magnetosphere (presumably, where's that magnetometer gone?) means that space weathering will have turned it reddish, too.
I was struck when looking at the images of comet 67-P that the miniature landscapes looked like something out of a 1950s SF movie or magazine cover, with properly jaggy peaks and dramatic gashes and boulders, unlike all the potatoes with grooves out there. 67_P was much more dramatic than the other comets we've seen, and in that respect is a bit of an outlier; my comments on the expectations around Ceres were intended to reflect that variability between expectation and actuality too.
Post by: kfsorensen on 02/24/2015 11:42 am
Post by: Star One on 02/24/2015 12:36 pm
Post by: Robotbeat on 02/24/2015 12:53 pm
What happened about the photos I thought were being taken on the 20th?If they were taken, then they haven't been released. Complain to the Europeans (Germans) who built the camera.
Post by: Bob Shaw on 02/24/2015 01:46 pm
Post by: the_other_Doug on 02/24/2015 04:23 pm
https://twitter.com/NASA_Dawn/status/568934417328001024 (https://twitter.com/NASA_Dawn/status/568934417328001024)
Post by: jacqmans on 02/25/2015 07:37 am
NASA Briefing to Discuss First Spacecraft Arrival at a Dwarf Planet
NASA’s Jet Propulsion Laboratory (JPL) will host a briefing at noon EST (9 a.m. PST) Monday, March 2, to discuss the March 6 arrival of the agency’s Dawn spacecraft at the dwarf planet Ceres. The news briefing, held at JPL’s von Karman Auditorium at 4800 Oak Grove Dr., Pasadena, California, will be broadcast live on NASA Television and streamed on the agency’s website.
Ceres, located in the main asteroid belt between Mars and Jupiter, is the largest unexplored world of the inner solar system. Dawn will not only be the first spacecraft to reach a dwarf planet, it will be the first spacecraft ever to orbit two different worlds in deep space.
Dawn was the first spacecraft to orbit a body in the main asteroid belt when it explored the giant asteroid Vesta from 2011 to 2012.
Participants in the news conference will be:
•Jim Green, director, Planetary Science Division, NASA Headquarters, Washington
•Robert Mase, Dawn project manager, JPL
•Carol Raymond, Dawn deputy principal investigator, JPL
To arrange access to attend in person or to obtain a telephone connection, reporters must contact Gina Fontes at 818-354-5011 or [email protected] no later than 3 p.m. EST (noon PST) on Friday, Feb. 27, and provide their media affiliation.
For NASA TV streaming video, scheduling and downlink information, visit:
http://www.nasa.gov/nasatv
The briefing will also be streamed live on Ustream at:
http://www.ustream.tv/nasajpl2
For information about NASA's Dawn mission, visit:
http://www.nasa.gov/dawn
Post by: Star One on 02/25/2015 08:16 am
They tweeted last Friday that it would be the middle of this week...
https://twitter.com/NASA_Dawn/status/568934417328001024 (https://twitter.com/NASA_Dawn/status/568934417328001024)
Thanks for that.
Post by: Quagga on 02/25/2015 03:31 pm
http://www.nasa.gov/jpl/dawn/bright-spot-on-ceres-has-dimmer-companion/
Post by: RotoSequence on 02/25/2015 04:18 pm
The Great Ceres White Spot imagery is still being withheld from release. :-\
Post by: ugordan on 02/25/2015 04:59 pm
The Great Ceres White Spot imagery is still being withheld from release. :-\
Not any more. Wow, that is much brighter than the surrounding terrain!
http://www.jpl.nasa.gov/news/news.php?feature=4491
Post by: NovaSilisko on 02/25/2015 05:05 pm
Post by: kevin-rf on 02/25/2015 05:12 pm
That, or it's aliens ;)
Post by: Helodriver on 02/25/2015 05:26 pm
Oooh, it's dead center in the bottom of the crater, Could it be a liquid that seeped in after impact, filled the bottom and froze?
That, or it's aliens ;)
My guess is that Ceres is made up mostly of ice or at least has a substantial solid ice layer underneath a thick layer of regolith and debris picked up from collisions with other asteroid belt objects. Large deep younger craters expose the ice which, through sublimation outgasses enough to keep that surface clean and with higher albedo.
That, or its aliens.
Post by: Damon Hill on 02/25/2015 05:43 pm
RC2 image release :)
http://www.nasa.gov/jpl/dawn/bright-spot-on-ceres-has-dimmer-companion/
The biggest visible crater/ring in these images is very interesting. Perhaps it is very old but it's visible as a relatively faint ring suggesting it's very shallow. I infer the surface composition of Ceres might be very plastic and has mostly filled it in. Hope I'll live long enough to see what a rover could discover about Ceres composition and possible dynamics of a liquid mantle.
Post by: NovaSilisko on 02/25/2015 05:47 pm
Post by: punder on 02/25/2015 05:52 pm
Maybe it's just an extremely white mineral, but it sure looks specular to me.
Sorry to inject such a tired cliche into the proceedings, but I must cover my butt here, just in case; so...
I, for One, Welcome Our New Ceresian Overlords. Thank you.
Post by: kevin-rf on 02/25/2015 06:39 pm
Maybe it's just an extremely white mineral, but it sure looks specular to me.Diamonds? They are a spacecrafts best friend after all...
Post by: Malderi on 02/25/2015 06:48 pm
Post by: Star One on 02/25/2015 06:56 pm
The Great Ceres White Spot imagery is still being withheld from release. :-\
Not any more. Wow, that is much brighter than the surrounding terrain!
http://www.jpl.nasa.gov/news/news.php?feature=4491
That was unexpected, that's far brighter than I thought it might be at this close range. An impact event exposing ice or a mineral of some type still seems most likely.
That or it's a Mysteron base.
Post by: the_other_Doug on 02/25/2015 06:57 pm
Has anyone ever studied a Ceres lander mission? If Dawn finds something really interesting, I would imagine those studies get dusted off. Someone, somewhere has studied landing, flying, and floating on/underneath the surface of just about every body in the solar system, so I'm sure there's something somewhere.
I'm sure someone, sometime, has run the trajectories and delta-V requirements for such a mission. But as for a science package, except for very general sensors appropriate for most any small-body mission, we just didn't know enough about Ceres to design a lander package specific to answering questions about Ceres itself.
That's about to change, of course... :D
Post by: Borklund on 02/25/2015 07:04 pm
Seriously though, what are those? This is intriguing
Post by: Quagga on 02/25/2015 07:12 pm
Has anyone ever studied a Ceres lander mission? If Dawn finds something really interesting, I would imagine those studies get dusted off. Someone, somewhere has studied landing, flying, and floating on/underneath the surface of just about every body in the solar system, so I'm sure there's something somewhere.
Apparently, China plans to conduct a Ceres sample return mission:
http://english.nssc.cas.cn/ns/NU/201410/W020141016603613379886.pdf
Post by: Moe Grills on 02/25/2015 07:15 pm
Oooh, it's dead center in the bottom of the crater, Could it be a liquid that seeped in after impact, filled the bottom and froze?
That, or it's aliens ;)
My guess is that Ceres is made up mostly of ice or at least has a substantial solid ice layer underneath a thick layer of regolith and debris picked up from collisions with other asteroid belt objects. Large deep younger craters expose the ice which, through sublimation outgasses enough to keep that surface clean and with higher albedo.
That, or its aliens.
:D They must have polished their huge motherships, both of them, real good. :D
Post by: saturnapollo on 02/25/2015 07:50 pm
Quote
That or it's a Mysteron base.
If it is, let's not shoot at them this time!
Keith
Post by: SimonFD on 02/25/2015 08:04 pm
The other thing that the picture reminded me of was the embedded diamond described in 2061:Odyssey Three
I have a feeling the asteroid mining start-ups will be seeing more interest (i.e. funding) after this.
Post by: Moe Grills on 02/25/2015 09:00 pm
Post by: Star One on 02/25/2015 09:07 pm
To be serious, there is little doubt that with belt-tightening in government, the budget for an extended Ceres orbital mission for the Dawn spacecraft may alas disappear. Which leaves the real possibility that NASA may get engineers to put the spacecraft into a terminal decaying orbit around Ceres until it is deliberately crashed onto the surface. That would be a bittersweet finale for Dawn.I thought the current plan was to leave it in a permanent orbit.
Anyway good article here on the latest updates.
http://www.planetary.org/blogs/guest-blogs/marc-rayman/0225-dawn-journal-ceres-deepening-mysteries.html
Post by: NovaSilisko on 02/25/2015 09:07 pm
To be serious, there is little doubt that with belt-tightening in government, the budget for an extended Ceres orbital mission for the Dawn spacecraft may alas disappear. Which leaves the real possibility that NASA may get engineers to put the spacecraft into a terminal decaying orbit around Ceres until it is deliberately crashed onto the surface. That would be a bittersweet finale for Dawn.
Everything I've seen from them thus far says they're going to just leave it in its lowest orbit after the mission is over. I'm going to assume that, if it's not extended, they'd simply shut it off and leave it in a stable orbit, not crash it into the surface. Why bother wit that?
Post by: mcgyver on 02/25/2015 09:26 pm
I'm rough guessing it, and also assuming there is no camera flare making it look bigger (probably a bad assumption), but wow!Could the fainter spot be just a camera artifact due to high brightness of main spot? I've just seen it happening in New Horizons image.
Camera team had even to rotate camera to get rid of fake bright pixels:
http://www.nasa.gov/nh_new-horizons-spots-small-moons-orbiting-pluto/#.VO5L6NJ5NEU
Post by: punder on 02/25/2015 09:33 pm
Of course! Finally!
We have a mission for Falcon Heavy's first flight!!!
:D
Post by: ugordan on 02/25/2015 09:41 pm
Could the fainter spot be just a camera artifact due to high brightness of main spot? I've just seen it happening in New Horizons image.
No. That's charge bleed and is continuous from the location that has saturated pixels and has really sharp edges since it's an artifact on the CCD and not a real feature convolved through the optical point spread function.
These two spots are real, although their "strong" brightness should be put into context of the overall dark Ceres' surface. I'm betting it's exposed patches of ice, might even not be completely pure ice but darker.
Post by: Orbiter on 02/25/2015 10:30 pm
Could the fainter spot be just a camera artifact due to high brightness of main spot? I've just seen it happening in New Horizons image.
No. That's charge bleed and is continuous from the location that has saturated pixels and has really sharp edges since it's an artifact on the CCD and not a real feature convolved through the optical point spread function.
These two spots are real, although their "strong" brightness should be put into context of the overall dark Ceres' surface. I'm betting it's exposed patches of ice, might even not be completely pure ice but darker.
Probably from a (relatively) recent impact I would hazard to guess.
Post by: mcgyver on 02/25/2015 10:43 pm
Found this data for albedo:
These two spots are real, although their "strong" brightness should be put into context of the overall dark Ceres' surface.
Moon: 12%
Ceres: 9%
67P comet: 5%
The best Hubble could do for albedo was mapping Ceres at 30 km/pixel:
http://www.hou.usra.edu/meetings/lpsc2015/pdf/1365.pdf (http://www.hou.usra.edu/meetings/lpsc2015/pdf/1365.pdf)
Interesting albedo comparison (you can barely see 67P in bottom right corner):
(http://i.kinja-img.com/gawker-media/image/upload/s--ZaTaeV_g--/c_fit,fl_progressive,q_80,w_636/snwjbk0sxhsldwvy8jzc.jpg)
http://io9.com/comet-67p-churyumov-gerasimenko-is-way-darker-than-we-r-1648171590
Post by: Lars-J on 02/25/2015 11:30 pm
Could the fainter spot be just a camera artifact due to high brightness of main spot? I've just seen it happening in New Horizons image.
No. That's charge bleed and is continuous from the location that has saturated pixels and has really sharp edges since it's an artifact on the CCD and not a real feature convolved through the optical point spread function.
These two spots are real, although their "strong" brightness should be put into context of the overall dark Ceres' surface. I'm betting it's exposed patches of ice, might even not be completely pure ice but darker.
Exactly. NASA does this frequently with images, making level adjustments (boosting contrast) to make the lightest parts of an image look white. A lot of Mars imagery has been released this way.
Post by: redliox on 02/25/2015 11:59 pm
Exactly. NASA does this frequently with images, making level adjustments (boosting contrast) to make the lightest parts of an image look white. A lot of Mars imagery has been released this way.
Yeah, I heard of them often tweaking color so everything looks pink-skyed liked when the Vikings initially landed. The Martian atmosphere constantly varies in color depending on dust levels, so its color can be anything from deep red to nearly sky blue...just depends on when the next dust storm stirs things up.
Post by: ugordan on 02/26/2015 12:01 am
Could the fainter spot be just a camera artifact due to high brightness of main spot? I've just seen it happening in New Horizons image.
No. That's charge bleed and is continuous from the location that has saturated pixels and has really sharp edges since it's an artifact on the CCD and not a real feature convolved through the optical point spread function.
These two spots are real, although their "strong" brightness should be put into context of the overall dark Ceres' surface. I'm betting it's exposed patches of ice, might even not be completely pure ice but darker.
Exactly. NASA does this frequently with images, making level adjustments (boosting contrast) to make the lightest parts of an image look white. A lot of Mars imagery has been released this way.
That's not what I'm saying. This isn't about white-balancing. Even with no manipulation, there is no way of getting a good sense of absolute brightness without knowing exposure settings used and even then you need a reference for what a given albedo would look like. Without that, no way of determining if it's a dark object with a long exposure or a bright object at a short exposure. Only thing that can be deduced is that the "bright" spot is significantly brighter than the "dark" stuff.
Case in point on an example of Comet 67P: https://twitter.com/elakdawalla/status/533229063587254272
If I only showed you the image on the right, would you really be able to say it's a dark-as-charcoal object?
Post by: Robotbeat on 02/26/2015 01:00 am
Post by: RotoSequence on 02/26/2015 01:08 am
Post by: Donosauro on 02/26/2015 02:33 am
Has anyone ever studied a Ceres lander mission? If Dawn finds something really interesting, I would imagine those studies get dusted off. Someone, somewhere has studied landing, flying, and floating on/underneath the surface of just about every body in the solar system, so I'm sure there's something somewhere.
Yep, a polar lander, in fact:
http://www.space.com/6583-lander-probe-dwarf-planet-ceres-life.html
http://www.researchgate.net/publication/258329327_Preliminary_assessment_of_a_Ceres_Polar_Lander_mission
Landing in a polar region was probably motivated by indications Ceres might have polar caps, something Dawn's Principal Investigator, Marc Rayman, mentioned in an earlier blog post, IIRC. And, there's this, a simulation which seems to show that seasonal "frost caps" would be possible, if you accept the study's assumptions: http://meetingorganizer.copernicus.org/EPSC2012/EPSC2012-280-1.pdf
YMMV.
Post by: mhlas7 on 02/26/2015 02:53 am
Has anyone ever studied a Ceres lander mission? If Dawn finds something really interesting, I would imagine those studies get dusted off. Someone, somewhere has studied landing, flying, and floating on/underneath the surface of just about every body in the solar system, so I'm sure there's something somewhere.
Yep, a polar lander, in fact:
http://www.space.com/6583-lander-probe-dwarf-planet-ceres-life.html
http://www.researchgate.net/publication/258329327_Preliminary_assessment_of_a_Ceres_Polar_Lander_mission
Landing in a polar region was probably motivated by indications Ceres might have polar caps, something Dawn's Principal Investigator, Marc Rayman, mentioned in an earlier blog post. And, there's this, a simulation which seems to show that seasonal "frost caps" would be possible, if you accept the study's assumptions: http://meetingorganizer.copernicus.org/EPSC2012/EPSC2012-280-1.pdf
YMMV.
Could the Mars Science Laboratory platform be re-purposed for Ceres? Re-entry may be challenging because of the atmosphere and the suspension would need to be adjusted for the different gravity. Would this be possible?
Post by: KelvinZero on 02/26/2015 03:46 am
Random armchair speculation: If a lump of iron buried itself into a mantle of ice, wouldnt you get some sort of chemical reaction over an extended time? Maybe the energy of the impact makes that irrelevant. I was imagining something hitting at say a 45 degree angle and bubbling up first through the original channel but later through the off center one.
Do we know anything about the hue of the two spots yet?
Post by: NovaSilisko on 02/26/2015 04:04 am
Could the Mars Science Laboratory platform be re-purposed for Ceres? Re-entry may be challenging because of the atmosphere and the suspension would need to be adjusted for the different gravity. Would this be possible?
Gonna guess you're new to this. ;)
The MSL platform was designed and built for one purpose - driving around mars. For a body as different as Ceres, it's better to design a vehicle from scratch for this new environment than try to beat another vehicle into something that will work in it.
I'm not sure what you mean about the atmosphere. Ceres has so little atmosphere you wouldn't know it was there without the right equipment. You wouldn't even do any reentry whatsoever. Just do a traditional lander with piggybacked rover.
Post by: Blackstar on 02/26/2015 04:17 am
But so far nothing like a Ceres lander has been studied by anybody in any detail. Maybe some basic back of the envelope calculations, but that's about it.
Post by: Lars-J on 02/26/2015 04:17 am
That's not what I'm sayingCould the fainter spot be just a camera artifact due to high brightness of main spot? I've just seen it happening in New Horizons image.
No. That's charge bleed and is continuous from the location that has saturated pixels and has really sharp edges since it's an artifact on the CCD and not a real feature convolved through the optical point spread function.
These two spots are real, although their "strong" brightness should be put into context of the overall dark Ceres' surface. I'm betting it's exposed patches of ice, might even not be completely pure ice but darker.
Exactly. NASA does this frequently with images, making level adjustments (boosting contrast) to make the lightest parts of an image look white. A lot of Mars imagery has been released this way.
That's not what I'm saying. This isn't about white-balancing. Even with no manipulation, there is no way of getting a good sense of absolute brightness without knowing exposure settings used and even then you need a reference for what a given albedo would look like. Without that, no way of determining if it's a dark object with a long exposure or a bright object at a short exposure. Only thing that can be deduced is that the "bright" spot is significantly brighter than the "dark" stuff.
When did I mention white balance? Level adjustment has no relation to white balance setting. No, I'm referring to the raw images returned from the rovers, often pre-adjusted before transmission for maximum contrast, which means they cannot be interpreted correctly without knowing reference data.
Post by: Lars-J on 02/26/2015 04:18 am
This NBC article (http://www.nbcnews.com/science/space/dawn-probe-spots-bright-surprise-ceres-it-ice-n312831), citing UCLA astronomer Chris Russell, says the albedo of the white spots is at least 40%.
Which is not that white, really...
Post by: Robotbeat on 02/26/2015 04:56 am
Almost as white as ocean ice. But remember, 40% is a lower bound! We haven't resolved the spot quite yet, the estimates for its albedo can only get higher.This NBC article (http://www.nbcnews.com/science/space/dawn-probe-spots-bright-surprise-ceres-it-ice-n312831), citing UCLA astronomer Chris Russell, says the albedo of the white spots is at least 40%.
Which is not that white, really...
Post by: ApolloStarbuck on 02/26/2015 06:05 am
You may be on to something there. Already visible in this image are several crater chains like the kind you see on the moon or on Jupiter's moons. http://en.wikipedia.org/wiki/Crater_chain
Here are two big crater chains I think I see, and a lunar image for comparison
I can't tell if it's a misleading artifact caused by the enhancement (seems likely) but the features I marked "1" look like long chains of craters.
The one marked "2" looks less like a photographic aberration and more like 3 nice little crates side by side.
But I have no idea. Not really qualified in that area of expertise.
Post by: Ben the Space Brit on 02/26/2015 06:35 am
Post by: RotoSequence on 02/26/2015 06:55 am
You may be on to something there. Already visible in this image are several crater chains like the kind you see on the moon or on Jupiter's moons. http://en.wikipedia.org/wiki/Crater_chain
Here are two big crater chains I think I see, and a lunar image for comparison
I can't tell if it's a misleading artifact caused by the enhancement (seems likely) but the features I marked "1" look like long chains of craters.
The one marked "2" looks less like a photographic aberration and more like 3 nice little crates side by side.
But I have no idea. Not really qualified in that area of expertise.
Now that you've got me looking for lines, there's actually quite a few of them, lighter and darker, running in that direction. Hmmm...
The other images released today seem to have diagonal lines running in the same direction. They might be an image processing artifact.
Post by: Bynaus on 02/26/2015 07:20 am
Regarding the white spot, it might also be the half-buried core of an iron impactor. Iron asteroids have relatively high albedos. I guess you would need a very low-velocity collision and perhaps also a higher-density surface somewhere further down within Ceres to have the core re-bound to the surface. Perhaps the two spots are two former lobes of the body, or perhaps it fragmented into several large chunks. In any case, that should be relatively easy to test (spectroscopically).
Ar volcanism. Or Aliens. ;)
Post by: ugordan on 02/26/2015 07:49 am
When did I mention white balance? Level adjustment has no relation to white balance setting. No, I'm referring to the raw images returned from the rovers, often pre-adjusted before transmission for maximum contrast, which means they cannot be interpreted correctly without knowing reference data.
They aren't pre-adjusted before transmission, they are histogram stretched here on the ground for purposes of publishing on the raw jpg website, usually to clip darkest areas to black and brightest to white. Not applicable here since darkest areas are already black space so any such operation amounts to normalizing the brightest portion of an image, which is analogous to exposure duration control in principle I already talked about. Even white-balancing comes down to a independent linear stretch of the 3 component images.
What you probably meant to say originally is that curve adjustments like gamma might have been done on this press release image, but that's irrespective of what the brightest part of the image is.
Post by: Nilof on 02/26/2015 10:25 am
Post by: cro-magnon gramps on 02/26/2015 10:59 am
These weird spots are getting quite a lot of attention from mainstream media. Even gaming websites are reporting on it. (http://www.ign.com/articles/2015/02/26/dwarf-planet-ceres-gets-another-unexplained-bright-spot)
I would call it the "Sci-Fi Unknown Effect"
Most of society has grown up with such a huge dose of sci-fi entertainment, with aliens and just plain "The Unknown" popping up, it is bound to cause some ripples.... Once it becomes known for a natural phenomena, it will go back to Ho-Humm... it did for that Moon that looked like it was right out of Star Wars...
Gramps
Post by: Star One on 02/26/2015 11:11 am
As she says hope it is because that's the more interesting answer and it would show how the impact craters have got so flattened out.
http://www.planetary.org/blogs/emily-lakdawalla/2015/02251857-ceres-geology.html
Post by: Proponent on 02/26/2015 02:45 pm
To be serious, there is little doubt that with belt-tightening in government, the budget for an extended Ceres orbital mission for the Dawn spacecraft may alas disappear. Which leaves the real possibility that NASA may get engineers to put the spacecraft into a terminal decaying orbit around Ceres until it is deliberately crashed onto the surface. That would be a bittersweet finale for Dawn.I thought the current plan was to leave it in a permanent orbit.
Mission director Marc Rayman has mentioned (http://archived.thespaceshow.com/shows/2401-BWB-2015-01-26.mp3) that Dawn will be left in a stable orbit when it expires, so as not to contaminate Ceres. If Ceres were not believed to have water, contamination would be less of a concern.
Post by: NovaSilisko on 02/26/2015 02:54 pm
IMO space agencies and instruments PIs should apply a marker on heavily enhanced celestial objects images, something like "Objects in the picture are darker than they appear".
Not sure about calling it heavily enhanced here, it's just a matter of using longer exposure times. Plus if you were to view it out a spacecraft window, your eyes would certainly adjust to the dark appearance of it.
Post by: mcgyver on 02/26/2015 04:04 pm
I attached below a random picture of Ceres how it would likely appear if the actual albedo was used: ~9% average (~charcoal), ~20% for the UNRESOLVED "white" spots (~asphalt):Assuming that the pixels of the bright dot are saturated as I read in prtevious posts and so we only know that they have at least 20% albedo, what does it prevent us from assuming 50, 80 or 100% albedo, and hence a white spot also in your image?
Post by: Lars-J on 02/26/2015 04:26 pm
When did I mention white balance? Level adjustment has no relation to white balance setting. No, I'm referring to the raw images returned from the rovers, often pre-adjusted before transmission for maximum contrast, which means they cannot be interpreted correctly without knowing reference data.
They aren't pre-adjusted before transmission, they are histogram stretched here on the ground for purposes of publishing on the raw jpg website, usually to clip darkest areas to black and brightest to white. Not applicable here since darkest areas are already black space so any such operation amounts to normalizing the brightest portion of an image, which is analogous to exposure duration control in principle I already talked about. Even white-balancing comes down to a independent linear stretch of the 3 component images.
What you probably meant to say originally is that curve adjustments like gamma might have been done on this press release image, but that's irrespective of what the brightest part of the image is.
No, I meant to say what I said. See here - http://pds-imaging.jpl.nasa.gov/Atlas/MER/documents/pancam_ug.pdf - paragraph 3.1, where it is explained how 12bit image data on the MER rovers was resampled ans scaled/stretched to 8 bit data prior to transmission.
So if the RAW data was not properly resampled back to 12 bit image with the proper transformation, the brightness level would be misinterpreted.
Is that clearer? That's how the Spirit/Opportunity rovers operated, this may not be how Dawn or MSL works. But then again, there appears to be no public access to Dawn RAW image data, so the point is moot.
Post by: ugordan on 02/26/2015 05:01 pm
Is that clearer? That's how the Spirit/Opportunity rovers operated, this may not be how Dawn or MSL works. But then again, there appears to be no public access to Dawn RAW image data, so the point is moot.
Yes, that is the LUT encoding and it's commonly use to encode 12 bits to 8 bits while considering that expected photon shot noise would affect the discarded 4 bits of dynamic range anyway. Cassini uses it most of the time, MRO uses it, MSL color cameras use it (the square root encoding actually approximates the display correct 2.2 gamma so MSL raw pancams look good out of the box). I'd bet Dawn uses such encoding or at the very least has it available.
But... it's not necessarily relevant here as the calibration procedure will linearize the data back. I would distinguish between what MER/MSL/Cassini call "raw" images (uncalibrated raw products) and what Dawn press releases appear to call raw images which, to me, look like actually calibrated images but with no additional processing like cleanup, cropping, zoom, etc.
In any case, we both agree that not much should be inferred from the press releases as you've indirectly touched upon on another problem, that of gamma correction of such images (or much more often, lack thereof). Loading linear calibrated I/F data into a photo editor that operates in sRGB by default will cause increased albedo contrast than what correct gamma treatment would. Based on my past experience, the latest Dawn image looks like one such image so that would mean the brightness difference is exaggerated. Previous releases I'm unclear about, they range from appearing gamma-corrected to high-pass filtered to increase surface details.
Post by: Star One on 02/26/2015 07:03 pm
I attached below a random picture of Ceres how it would likely appear if the actual albedo was used: ~9% average (~charcoal), ~20% for the UNRESOLVED "white" spots (~asphalt):Assuming that the pixels of the bright dot are saturated as I read in prtevious posts and so we only know that they have at least 20% albedo, what does it prevent us from assuming 50, 80 or 100% albedo, and hence a white spot also in your image?
Most planetologists agree on that 20% value, wherever they got the information. As I said better resolution may improve this, but the attention of many media and the general public is based on the incorrect understanding those spots are really "white".Not sure about calling it heavily enhanced here, it's just a matter of using longer exposure times. Plus if you were to view it out a spacecraft window, your eyes would certainly adjust to the dark appearance of it.
We have no info about what has been done on those pictures yet but, again, with all due respect and enormous excitation for the Dawn results, I think this is misleading the general public (not the scientists, of course). Driven by a discussion I had on another forum, I tried to better understand how much they can be defined "white" (rather than "brighter", for example). In science, careful wording should always be used.
This is what I'm questioning, not the absolute brightness of the images that, as you correctly pointed out, depend on illumination (aka exposure time and sensitivity).
BTW, this is a better normalisation of an area around the double bright spot. Now the spot is really close to 20% of saturation, and the surrounding area around 10%.
ADD: as a comparison, the Moon has an average albedo of 12%, but "Bright" spots (http://the-moon.wikispaces.com/Cassini%27s+Bright+Spot) at about 16-18% level.
Yet with all due respect you see fit too comment on the photos misleading the public yet admit you do not know what actual processing was done on them.
Post by: IRobot on 02/26/2015 07:21 pm
IMO space agencies and instruments PIs should apply a marker on heavily enhanced celestial objects images, something like "Objects in the picture are darker than they appear".Not really. The human eye is capable of an enormous dynamic range. And the crappy LCDs we are using are only capable of 256 shades of gray. Some of them only 64!
So histogram compression and/or gamma adjustment is a way to compensate for crappy monitors.
Post by: Blackstar on 02/26/2015 07:32 pm
I attached below a random picture of Ceres how it would likely appear if the actual albedo was used: ~9% average (~charcoal), ~20% for the UNRESOLVED "white" spots (~asphalt):Assuming that the pixels of the bright dot are saturated as I read in prtevious posts and so we only know that they have at least 20% albedo, what does it prevent us from assuming 50, 80 or 100% albedo, and hence a white spot also in your image?
Most planetologists agree on that 20% value, wherever they got the information. As I said better resolution may improve this, but the attention of many media and the general public is based on the incorrect understanding those spots are really "white".Not sure about calling it heavily enhanced here, it's just a matter of using longer exposure times. Plus if you were to view it out a spacecraft window, your eyes would certainly adjust to the dark appearance of it.
We have no info about what has been done on those pictures yet but, again, with all due respect and enormous excitation for the Dawn results, I think this is misleading the general public (not the scientists, of course). Driven by a discussion I had on another forum, I tried to better understand how much they can be defined "white" (rather than "brighter", for example). In science, careful wording should always be used.
This is what I'm questioning, not the absolute brightness of the images that, as you correctly pointed out, depend on illumination (aka exposure time and sensitivity).
BTW, this is a better normalisation of an area around the double bright spot. Now the spot is really close to 20% of saturation, and the surrounding area around 10%.
ADD: as a comparison, the Moon has an average albedo of 12%, but "Bright" spots (http://the-moon.wikispaces.com/Cassini%27s+Bright+Spot) at about 16-18% level.
Yet with all due respect you see fit too comment on the photos misleading the public yet admit you do not know what actual processing was done on them.
You misunderstood him. He was discussing the use of the word "white" as misleading when what is being discussed is a slightly paler shade of nearly black.
There's no way to get around the fact that people are going to misunderstand this stuff. It can be qualified until the cows come home (where are those damned cows anyway?), but people are still not going to get it. They're going to think this is a bright spot, not realizing that we're talking about something that is very dark to begin with.
Post by: notsorandom on 02/26/2015 07:46 pm
The human eye is very impressive in the dynamic range it can cover. If a human were in a spacecraft orbiting Ceres they would have no trouble seeing it against the black background of space. It likely wouldn't look all that dark either compared to how black space is.IMO space agencies and instruments PIs should apply a marker on heavily enhanced celestial objects images, something like "Objects in the picture are darker than they appear".Not really. The human eye is capable of an enormous dynamic range. And the crappy LCDs we are using are only capable of 256 shades of gray. Some of them only 64!
So histogram compression and/or gamma adjustment is a way to compensate for crappy monitors.
Post by: Star One on 02/26/2015 08:28 pm
I attached below a random picture of Ceres how it would likely appear if the actual albedo was used: ~9% average (~charcoal), ~20% for the UNRESOLVED "white" spots (~asphalt):Assuming that the pixels of the bright dot are saturated as I read in prtevious posts and so we only know that they have at least 20% albedo, what does it prevent us from assuming 50, 80 or 100% albedo, and hence a white spot also in your image?
Most planetologists agree on that 20% value, wherever they got the information. As I said better resolution may improve this, but the attention of many media and the general public is based on the incorrect understanding those spots are really "white".Not sure about calling it heavily enhanced here, it's just a matter of using longer exposure times. Plus if you were to view it out a spacecraft window, your eyes would certainly adjust to the dark appearance of it.
We have no info about what has been done on those pictures yet but, again, with all due respect and enormous excitation for the Dawn results, I think this is misleading the general public (not the scientists, of course). Driven by a discussion I had on another forum, I tried to better understand how much they can be defined "white" (rather than "brighter", for example). In science, careful wording should always be used.
This is what I'm questioning, not the absolute brightness of the images that, as you correctly pointed out, depend on illumination (aka exposure time and sensitivity).
BTW, this is a better normalisation of an area around the double bright spot. Now the spot is really close to 20% of saturation, and the surrounding area around 10%.
ADD: as a comparison, the Moon has an average albedo of 12%, but "Bright" spots (http://the-moon.wikispaces.com/Cassini%27s+Bright+Spot) at about 16-18% level.
Yet with all due respect you see fit too comment on the photos misleading the public yet admit you do not know what actual processing was done on them.
You misunderstood him. He was discussing the use of the word "white" as misleading when what is being discussed is a slightly paler shade of nearly black.
There's no way to get around the fact that people are going to misunderstand this stuff. It can be qualified until the cows come home (where are those damned cows anyway?), but people are still not going to get it. They're going to think this is a bright spot, not realizing that we're talking about something that is very dark to begin with.
I don't disagree with the use of the term 'white' as being unhelpful. But be that as it may there's no getting around the fact that there is still a considerable difference in the albedo of these objects and the rest of Ceres. We aren't talking a small difference and has already been mentioned an astronaut in orbit around Ceres would probably have no issue seeing them with the mark one human eyeball.
Post by: Lars-J on 02/26/2015 08:42 pm
IMO space agencies and instruments PIs should apply a marker on heavily enhanced celestial objects images, something like "Objects in the picture are darker than they appear".Not really. The human eye is capable of an enormous dynamic range. And the crappy LCDs we are using are only capable of 256 shades of gray. Some of them only 64!
So histogram compression and/or gamma adjustment is a way to compensate for crappy monitors.
Exactly. And bright and dark are completely relative terms.
Post by: pagheca on 02/26/2015 09:49 pm
Exactly. And bright and dark are completely relative terms.
Correct. And that's why we use albedo rather than brightness.
p.s. just noticed that while many professional commentators do, JPL is correctly *not* using the word "white" but just "bright" in its webpages (http://www.jpl.nasa.gov/news/news.php?feature=4491).
Post by: meekGee on 02/27/2015 12:15 am
Two observations:
The largest spot is very centered within the crater. It's likely IMO that they are related - either this is the impactor, or it's a later phenomenon caused by the crater (e.g. accumulated ice) The second spot can be a big chunk of the impactor, or a second accumulation point for ice.
On the left side of the image are two more brighter areas.
Post by: Lars-J on 02/27/2015 12:26 am
So if the brightest spots have an albedo of 40%, it matches pretty well with typical dry sand.
Post by: NovaSilisko on 02/27/2015 12:41 am
typical dry sand.
Sand comes in a lot of different colors, more than the range there would cover... what defines "typical" sand, anyway? Standard stock photo beach sand, I guess?
Post by: meekGee on 02/27/2015 12:50 am
On earth, typical materials are always in a stable state in an Oxygen environment, and so their appearance might not be the same
So for example, on Earth we find Sand, not Silicon. What do we expect on Ceres?
Post by: Lars-J on 02/27/2015 12:53 am
typical dry sand.
Sand comes in a lot of different colors, more than the range there would cover... what defines "typical" sand, anyway? Standard stock photo beach sand, I guess?
I would guess so. It's not a very specific chart. :)
Post by: Robotbeat on 02/27/2015 01:34 am
Caltech professor I believe recently updated that to 40%.I attached below a random picture of Ceres how it would likely appear if the actual albedo was used: ~9% average (~charcoal), ~20% for the UNRESOLVED "white" spots (~asphalt):Assuming that the pixels of the bright dot are saturated as I read in prtevious posts and so we only know that they have at least 20% albedo, what does it prevent us from assuming 50, 80 or 100% albedo, and hence a white spot also in your image?
Most planetologists agree on that 20% value, wherever they got the information. As I said better resolution may improve this, but the attention of many media and the general public is based on the incorrect understanding those spots are really "white". ...
If the PREVIOUS estimate were 20%, then these closer pictures ought to be more like 40% (minimum), and still the spot is unresolved so 40% would be a minimum, not a maximum.
Honestly, why are people so caught up on the idea it's relatively bright stuff? I mean, in all probability, any single image (if the spot is not yet resolved) is not likely to be THE actual peak albedo but just a minimum, so with each new image that doesn't resolve the spot, our estimates that the TRUE peak albedo are fairly high should improve.
Post by: KelvinZero on 02/27/2015 02:26 am
About the whiteness/lightness discussion, separate from the science, seeing how bright our moon seems at night despite its dark color, Im guessing an astronaut whose eyes have adjusted would really see a spectacular bright spot. Im just happy there is something to give Ceres a bit of character even to a total layman.
Does anyone know if there is any significant color differentiation to the human eye? I assume we would already know if the spot was off-white in color because it was detected even in those hubble images.
Post by: Robotbeat on 02/27/2015 02:32 am
Post by: KelvinZero on 02/27/2015 05:37 am
Dry salt would have an albedo of about 0.5, which is the bottom end of ocean ice albedo. So if it's higher than .5, it is not likely to be salt (and still, I find salt to be unlikely).You mean table salt? I really just meant some mineral dissolved into the ice and left behind when the water evaporates. I heard ice wouldn't last long on the surface.
Post by: Ben the Space Brit on 02/27/2015 08:51 am
Regarding the Great White Spot. Remember that, whatever it is, it is brightly visible from as far away as Low Earth Orbit, at least at certain ultraviolet wavelengths. That's how it was discovered by Hubble, after all. I wonder if there is already enough data available (ultraviolet and visual spectra as well as albedo at those wavelengths) to make a stab at deducing its' composition?
Post by: gospacex on 02/27/2015 11:20 am
Here's Phil Stooke's map from the above link.
It seems that that white spot is not unique.
There's another one in southern hemisphere (slightly below of center in the image) which also sits in the center of a crater. It happened to be near the limb in all photos so far, making it much less obvious.
A number of other small whitish spots are also visible.
Post by: mcgyver on 02/27/2015 01:25 pm
Post by: ugordan on 02/27/2015 01:33 pm
Post by: Nilof on 02/27/2015 03:15 pm
Post by: KelvinZero on 02/27/2015 03:29 pm
The imaging spectrometer onboard has more than 2.5x worse spatial resolution than the FC and the bright spot is currently barely resolved by the latter insturment.Genuine question because I know how little I know here.. Why does that matter? Even if the entire surrounding crater fit in a single pixel, if that pixel showed a unique spike in water or another chemical it would be pretty good evidence wouldnt it?
Post by: Robotbeat on 02/27/2015 07:18 pm
Indeed, unless it was regularly replenished. There is, after all, a slight detectable atmosphere of water vapor on Ceres.Dry salt would have an albedo of about 0.5, which is the bottom end of ocean ice albedo. So if it's higher than .5, it is not likely to be salt (and still, I find salt to be unlikely).You mean table salt? I really just meant some mineral dissolved into the ice and left behind when the water evaporates. I heard ice wouldn't last long on the surface.
Post by: catdlr on 02/27/2015 08:03 pm
Dawn, Mission to the Asteroid Belt (HD) – Narrated by Leonard Nimoy
Published on Feb 27, 2015
Produced in 2007, this overview video about NASA's Dawn mission to giant asteroid Vesta and dwarf planet Ceres was released before the spacecraft's launch that year. The mission greatly appreciated Leonard Nimoy's support and participation. Dawn investigated Vesta in 2011-2012, and will arrive at Ceres March 6, 2015.
https://www.youtube.com/watch?v=4ObsViTRT18
Post by: catdlr on 02/27/2015 08:14 pm
http://science.nasa.gov/science-news/science-at-nasa/2015/27feb_cerespuzzle/
Post by: Bob Shaw on 02/27/2015 11:08 pm
I attached below a random picture of Ceres how it would likely appear if the actual albedo was used: ~9% average (~charcoal), ~20% for the UNRESOLVED "white" spots (~asphalt):
I did it manually, so allow for some unbalance, but this is certainly more realistic than what has been advertised everywhere. Only caveat is that IF "white" spots are MUCH smaller than a pixel, they could become whiter once the probe is closer.
Forget clean glaciers, "salar", and alien cities, although large parking lots cannot be totally excluded. :)
An albedo chart is available here (https://www.fxguide.com/wp-content/uploads/2013/06/Albedo_values.jpg?18d488).
IMO space agencies and instruments PIs should apply a marker on heavily enhanced celestial objects images, something like "Objects in the picture are darker than they appear".
No, that really doesn't help at all. The human eye/brain combo doesn't depend on albedo alone. The Moon is pretty dark, but looks bright in the sky and is easily visible in daylight. Just darkening an image gives a quite false impression, sorry.
Post by: MATTBLAK on 02/27/2015 11:10 pm
Post by: Bob Shaw on 02/27/2015 11:14 pm
I hope they name a large crater on Ceres for Mr Nimoy... :(
And a few other SF greats - though Isaac Asimov should be commemorated elsewhere, as 'Marooned off Vesta' was (IFIRC) his first published and paid-for story. Ian Banks should have a HUGE structure as a memorial...
Post by: kfsorensen on 02/28/2015 02:17 am
I hope they name a large crater on Ceres for Mr Nimoy...
Hear, hear.
He's not dead, as long as we remember him.
Post by: catdlr on 02/28/2015 09:59 am
Scheduled for Mar 2, 2015
NASA's Jet Propulsion Laboratory will host a briefing at 9 a.m. PST (noon EST) Monday, March 2, to discuss the March 6 arrival of the agency's Dawn spacecraft at the dwarf planet Ceres. The news briefing, held at JPL's von Karman Auditorium at 4800 Oak Grove Dr., Pasadena, California, will be broadcast live on NASA Television and streamed here.
Ceres, located in the main asteroid belt between Mars and Jupiter, is the largest unexplored world of the inner solar system. Dawn will not only be the first spacecraft to reach a dwarf planet, it will be the first spacecraft ever to orbit two different worlds in deep space.
Dawn was the first spacecraft to orbit a body in the main asteroid belt when it explored the giant asteroid Vesta from 2011 to 2012.
Participants in the news conference will be:
-- Jim Green, director, Planetary Science Division, NASA Headquarters, Washington
-- Robert Mase, Dawn project manager, JPL
-- Carol Raymond, Dawn deputy principal investigator, JPL
https://www.youtube.com/watch?v=sJr-pctUYdw
Post by: Bob Shaw on 02/28/2015 12:02 pm
I hope they name a large crater on Ceres for Mr Nimoy...
Hear, hear.
He's not dead, as long as we remember him.
Sorry, he's dead, Jim...
Post by: Bob Shaw on 02/28/2015 12:11 pm
Our Moon is pretty dark, but can appear dazzlingly bright in the night sky - try using a telescope on it when full without filters and enjoy the discomfort).
Here's a manipulated version of the previous 'true albedo' full-on image of Ceres, lightened and with the contrast also altered. I've also blurred it substantially to bring out the tonal range of the markings rather than having one's eye trapped by the hard edges of pixels. The left hand side of Ceres suddenly becomes rather interesting - almost as though we're seeing a large but relatively subdued ray system. I'd ignore the bright limb on the right, though, which looks like a processing artefact to me.
Post by: pagheca on 02/28/2015 03:28 pm
No, that really doesn't help at all. The human eye/brain combo doesn't depend on albedo alone. The Moon is pretty dark, but looks bright in the sky and is easily visible in daylight. Just darkening an image gives a quite false impression, sorry.
You are fully right, actually. I got too enthusiastic about the idea of disproving the however incorrect idea* that Ceres spots are white, and not just "brighter", as correctly reported by professional astronomers but not by media to the general public.
The obnoxious "Fifty Shades of Grey" publicity got eventually too far in my brain...
However, it would really be interesting to create a collection of space pictures (Mars, Ceres, but also star formation regions or the center of the Galaxy) as close as possible to how they would look to a human eye for brightness, resolution, chroma and view angle. I searched around but found little.
* as far as we know today
Post by: zubenelgenubi on 02/28/2015 08:28 pm
I hope they name a large crater on Ceres for Mr Nimoy... :(
And a few other SF greats - though Isaac Asimov should be commemorated elsewhere, as 'Marooned off Vesta' was (IFIRC) his first published and paid-for story. Ian Banks should have a HUGE structure as a memorial...
Sorry to be the rain on the parade gaining steam here...
The International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN) has themes determining the "Categories for Naming Features on Planets and Satellites."
http://planetarynames.wr.usgs.gov/Page/Categories (http://planetarynames.wr.usgs.gov/Page/Categories)
For Ceres:
Craters: Gods and goddesses of agriculture and vegetation from world mythology
Other features: Names of agricultural festivals of the world
However, Isaac Asimov DOES have commemoration on Titan:
Freta: Names of characters from the Foundation series of science fiction novels by American author Isaac Asimov (1920-1992)
And what are freta (singular fretum)?
Fretum, freta (FT) Strait, a narrow passage of liquid connecting two larger areas of liquid
What about Mercurian features?
Craters: Deceased artists, musicians, painters, and authors who have made outstanding or fundamental contributions to their field and have been recognized as art historically significant figures for more than 50 years
We just celebrated the 50th anniversary of the filming of the 1st Star Trek pilot, "The Cage."
But, these decisions are not set in stone.
Zubenelgenubi
Post by: clongton on 02/28/2015 08:45 pm
I, for One, Welcome Our New Ceresian Overlords. Thank you.
Be careful what you ask for.
Post by: clongton on 02/28/2015 08:52 pm
... NASA may get engineers to put the spacecraft into a terminal decaying orbit around Ceres until it is deliberately crashed onto the surface.
That would contaminate the surface.
Post by: punder on 02/28/2015 09:29 pm
I, for One, Welcome Our New Ceresian Overlords. Thank you.
Be careful what you ask for.
Yeah... that was a joke.
I'm betting subsurface ice, melted by a recent impact, upwelling and freezing on the surface.
Post by: Bob Shaw on 02/28/2015 10:05 pm
However, it would really be interesting to create a collection of space pictures (Mars, Ceres, but also star formation regions or the center of the Galaxy) as close as possible to how they would look to a human eye for brightness, resolution, chroma and view angle. I searched around but found little.
* as far as we know today
Sounds like something that the estimable Ted Stryk - http://planetimages.blogspot.co.uk/ - might have done/be persuaded to do.
Post by: IRobot on 02/28/2015 10:16 pm
However, it would really be interesting to create a collection of space pictures (Mars, Ceres, but also star formation regions or the center of the Galaxy) as close as possible to how they would look to a human eye for brightness, resolution, chroma and view angle.That makes no sense because the human eye has a much higher dynamic and chromatic range than a computer monitor can display, not to mention it can adapt to different brightness conditions of different parts of an extended object.
Also trained amateur astronomers observers can use the rod cells (peripheral vision) to see much more faint details.
There has been much discussion on amateur astronomer forums regarding extreme image processing that sometimes is employed. My idea on the subject is this:
- if you do it as art, you can do whatever you want. Fake spikes to simulate a reflector telescope? No problem!
- if you do it for scientific purposes, you must first make sure you are not destroying, adding or changing data. Then you also must make sure that the data is easily analyzed. That justifies extreme histogram stretches, gamma curves adjustments, color palettes, pseudo colors, etc.
I develop software and hardware for scientific imaging and these are common processing steps.
Post by: KelvinZero on 02/28/2015 11:00 pm
There goes the livelihood of every photoshop user in the world ;)However, it would really be interesting to create a collection of space pictures (Mars, Ceres, but also star formation regions or the center of the Galaxy) as close as possible to how they would look to a human eye for brightness, resolution, chroma and view angle.That makes no sense because the human eye has a much higher dynamic and chromatic range than a computer monitor can display, not to mention it can adapt to different brightness conditions of different parts of an extended object.
We probably just have to admit there has to be some sort of calibration with respect to the environment you are viewing the image from. I think it should be possible to create an image with a grey colour bar and tell the audience that "if that bar looks mid grey to you, then this is about what Ceres would look like to someone floating in the dark above it.
Something like that anyway.
(edit) Another thing you might want to explain is the actual colors of the materials without respect to the light actually falling on them, ie what would Ceres look like under a 'white' light. On a monitor this has to be calibrated but I guess if you printed it out it could be correct wherever you viewed it. If the Ceres surface reflects 40% of the light at one surface location, the printed version should reflect 40% there and so on.
Post by: Robotbeat on 03/01/2015 02:56 am
(Sorry, I had to!)
EDIT: Um, this is an updates thread?? Who'd have thunk!
Post by: Danderman on 03/01/2015 03:59 am
To be serious, there is little doubt that with belt-tightening in government, the budget for an extended Ceres orbital mission for the Dawn spacecraft may alas disappear. Which leaves the real possibility that NASA may get engineers to put the spacecraft into a terminal decaying orbit around Ceres until it is deliberately crashed onto the surface. That would be a bittersweet finale for Dawn.
As an alternative, some sort of extra low orbit that would provide very high resolution would be interesting.
Post by: the_other_Doug on 03/01/2015 05:00 am
To be serious, there is little doubt that with belt-tightening in government, the budget for an extended Ceres orbital mission for the Dawn spacecraft may alas disappear. Which leaves the real possibility that NASA may get engineers to put the spacecraft into a terminal decaying orbit around Ceres until it is deliberately crashed onto the surface. That would be a bittersweet finale for Dawn.
As an alternative, some sort of extra low orbit that would provide very high resolution would be interesting.
Neither will happen. Since Dawn has lost one of its reaction wheels, it needs to use a lot more of its RCS fuel to maintain attitude than it otherwise would, and would run out rather quickly if it tried to do the maneuvers needed to get good images from a lower orbit (the entire spacecraft has to slew to provide motion compensation in such a low orbit around a small body).
Dawn will not go into an orbit lower than its primary science orbit, and it will not be crashed into Ceres. It will be placed into a stable graveyard orbit around Ceres once funding for extended missions runs out, or the propellant runs out (whichever happens first). That's what its mission planners have said, and that's what they are going to do.
Post by: mcgyver on 03/01/2015 09:11 am
EDIT: Um, this is an updates thread?? Who'd have thunk!mmmhh this is a good point... Where should be posto "general discussion" messages about Dawn?
While we wait for the new thread, I have a question: just in case the asteroid belt origin is fragmentation of an ancient planet, how could it be demonstrated by analysis of remaining asteroids? I think it would be difficult by analysing Ceres, as it is so large that it didn't keep its original fragment-shape (assuming it was a fragment), but its "strong" gravity turned it into spherical shape; but apart from shape, if the ancient planet was, say, like Mars, what would we see today in its fragments?
Post by: Chris Bergin on 03/01/2015 01:07 pm
Post by: pagheca on 03/01/2015 05:39 pm
Ceres is ~ 2.77 AU from the Sun. This approx. means that sunlight brightness at Ceres distance would be about 13% than that at average Moon distance.
Moon average albedo is 0.12
Ceres average albedo is 0.09
Ceres brightest spot albedo is >0.4 (we assume this minimum value in the following)
Moon Luminance: 2500 Nit.
=> Ceres average luminance: 2500 * 0.13 * 0.09/0.12 = 243 Nit
=> Ceres brightest spot luminance: 2500 * 0.4 * 0.09 /0.12 = 750 Nit.
Now, question is: how much "bright" would those sources look to a human eye?
For comparison, a MacBook Pro Retina monitor, set at max brightness (and on white), is about 300 Nit, while other brand laptops show something typically between 200 or 250.
That suggest that Ceres in average would look almost as bright (per unit of area) as pure RGB white as seen on a quite good laptop screen set at max brightness (I assume Dawn seeing a full Ceres), while the brightest spots would look much brighter, almost dazzling.
I confess this is very surprising for me. Do you see any mistake?
Moreover, when the "twin spots" picture was taken, the apparent diameter of Ceres was about 1.15 deg. This means Ceres would look more than twice larger in diameter than a full Moon in the black sky.
If you spot any major error please let me know. I'm not very familiar with units used at optical wavelengths.
EDIT:
(1) I'm not completely sure that the Moon luminance value I used (2500 Nit) is valid inside or outside the atmosphere. I assumed the first one. Therefore, I removed any reference to atmospheric attenuation.
(2) I found somewhere very different values, up to 6000 Nit, for Moon luminance.
Post by: Lars-J on 03/02/2015 05:11 am
And talking about how bright a MacBook display appears to the human eye - which is VERY dynamic in how it interprets brightness - Is *meaningless* without something to compare on. Is it brighter than a MacBook appears in a dark room, or how it appears outside?
Post by: pagheca on 03/02/2015 06:45 am
I think you are mixing up relative (albedo) and absolute (nit) measurements.
No because I re-normalised Moon luminance, not just its albedo like I mistakenly did earlier.
And talking about how bright a MacBook display appears to the human eye - which is VERY dynamic in how it interprets brightness - Is *meaningless* without something to compare on. Is it brighter than a MacBook appears in a dark room, or how it appears outside?
The same.
Luminance is an objective physical quantity. I used a monitor for comparison because its luminance doesn't depend from ambience brightness (note the wording, and up to a certain level, as monitors unfortunately reflect some light), like a printout for example. The eye will adjust if the monitor is surrounded by a bright environment, but luminance will remain the same.
In this sense I don't think this discussion is "non-sense". A Planetary, or just a well calibrated, good LCD monitor in a dark room would allow to simulate pretty well the luminance and chroma of a picture to the actual scenario.
Post by: Lars-J on 03/02/2015 06:54 am
And talking about how bright a MacBook display appears to the human eye - which is VERY dynamic in how it interprets brightness - Is *meaningless* without something to compare on. Is it brighter than a MacBook appears in a dark room, or how it appears outside?
The same.
Luminance is an objective physical quantity. I used a monitor for comparison because its luminance doesn't depend from ambience luminosity, like a printout for example. The eye will adjust if the monitor is surrounded by a bright environment, but luminance will remain the same.
But it won't APPEAR to be the same to the naked eye. (Note the wording I used)
And your original question was "Now, question is: how much "bright" would those sources look to a human eye?"
Our eyes are okay at seeing relative brightness difference within a field of view, but absolutely terrible at gauging exact luminance.
Post by: zubenelgenubi on 03/02/2015 04:04 pm
Introductions are made; JPL Director Dr. Elachi delivers brief remarks, includes thanking Dawn team and mention of ion propulsion.
New content will be released today.
Post by: zubenelgenubi on 03/02/2015 04:15 pm
Dawn is NOT a NASA acronym!
Bob Mase is next. He is the Dawn program manager at JPL, participating from JPL.
Some background on Ceres.
Orbital capture March 6 around 4:20 am (Pacific ST?). Craft will not be linked to Earth at that time.
Solar arrays. Ion propulsion. Explanation given of the ion propulsion, including the total delta-v over the mission.
Capture at altitude of approx. 25,000 miles.
Currently over night side of Ceres for about a month--no imagery now.
1st science orbit in April--next imagery.
Drop in 4 "steps" to final science orbit at altitude 235 miles.
June 2016--end of primary mission.
Dawn is in excellent condition and on course.
edits--addition/clarification/spelling from my notes
Post by: Razer on 03/02/2015 05:01 pm
Dawn is in excellent condition and on course.
Not quite Dawn lost 2 of 4 electrically powered reaction wheels, and now it doesn't point with non renewable fuel, it will run out of fuel quickly.
Post by: zubenelgenubi on 03/02/2015 05:07 pm
Ceres is round. Compares Ceres to Europa and Enceladus regarding lower bulk density. This infers that more volatiles have been retained from formation.
Contrasts Ceres to our Moon and Vesta--they have a higher bulk density and therefore less volatiles.
Craters and fractures have been noted. These may be clues to information about the hypothesized subsurface ice layer.
Bright spots noted at low latitudes. The 2 very bright spots are a surprise! Water vapor deposits or salts deposits are two likely substances composing these very bright spots.
Possible correlation between Herschel Space Observatory observations of water vapor and the very bright spots. They will pursue this.
Or, they could be artifacts of impact heating--deposits.
One large impact basin particularly mentioned--this feature lacks depth and height and the interior appears smooth. The vertical features are "relaxed." The same is true for some smaller craters in the same region. (my comment--The basin floor appears convex--matching the exterior of the basin--as it crosses the terminator.)
Looking back at Dawn Vesta observations:
Hydrogen deposits found, correlating with carbon-rich deposits. These are thought to result from the impact of wet, volatile-rich asteroid impacts onto Vesta. Similarly-composed asteroids would deliver volatiles to the early Earth.
Water vapor observed by Herschel--released from the sub-surface or liberated by impact heating?
(Dawn PI Chris Russell later commented from the JPL briefing room audience.)
2 rounds of edits--additions/clarifications
Post by: zubenelgenubi on 03/02/2015 05:10 pm
Dawn is in excellent condition and on course.
Not quite Dawn lost 2 of 4 electrically powered reaction wheels, and now it doesn't point with non renewable fuel, it will run out of fuel quickly.
Well, I didn't say that. I believe Bob Mase did. I'm transcribing my notes taken from the briefing now.
I will say here that I didn't hear mention of reaction wheels during the briefing. They did mention, later, hydrazine as attitude control fuel as the primary limiter of an extended mission.
edit: spelling
Post by: zubenelgenubi on 03/02/2015 05:31 pm
from JPL, phone, and social media
Will there be a real-time signal that orbital capture has occurred?
No, Dawn will not be in communication at that time. Several hours later, early afternoon PST, the Deep Space Network will be in communication with the craft, and confirmation of capture is expected then.
Can you speculate on the geological activity and do you expect to see evidence of geological activity due to tidal forces?
Tidal--NO. (My comment--there's no nearby large object or objects to raise substantial tides--they vary as the inverse of the distance CUBED. 1/r3. Example: Earth and Moon.)
Solar energy could be a driver of activity. Ceres is closer to the Sun than the moons of the outer planets.
Perhaps the ice layer (mantle) is convecting. If so, there may be surface material visible, derived from the water/rock boundary (mantle/core boundary). There may be surface cracks (faults?).
What about Ceres plumes? re: Herschel observations--water vapor production is very low. If this is localized production (as opposed to diffusely all over the surface), then there may be plumes. Dawn's instruments were not designed to look for these, but the science team will do the best that they can with the instruments aboard. The camera will look for dust in plumes via forward-scattered sunlight. (My comment--also used by Cassini at Enceladus.) The infrared spectrometer will look for water vapor via limb observations. These observations can start with the first science orbit in late April.
edit: added a little to the tide comment
Post by: MajorBringdown on 03/02/2015 05:41 pm
I guess that could suggest that the bright spot elevation is much higher than the surrounding terrain such that it remains out of shadow and is still illuminated by the sun. I suppose a geyser could also also cause that.
Anyway, that's just a thought... I have no expertise in any of these areas, I'm just pulling guesses out of my backside.
Video (sorry if it's already been linked, I don't think it has):
https://www.youtube.com/watch?v=WLu4P4goZ1s
Post by: zubenelgenubi on 03/02/2015 06:10 pm
Geometry of bright spots? No new observations currently being taken--Dawn is over Ceres' dark/night side.
When the craft reaches the RC3 orbit, there will be better resolution. The current images are not yet FULLY CALIBRATED (my comment--this reflects on earlier discussion in this thread). They will correlate the imagery for the optical geometry and reflective characteristics.
Cryovolcanism?
If there is any, they expect to see a constructional feature (ex. central peak or mound) with deposit around the construction. Source could also be a crack, with no obvious mound. There's currently no match seen of this hypothesis with the observed bright spot topography.
A background question regarding the subsurface ice.
Ceres' round-ness was known from Hubble observations. From the computed density, it was known that Ceres had retained volatiles. Modelling from that, it's hypothesized that Ceres differentiated into a rocky core and a icy mantle. Adding the expected complement of radioactive elements creates enough heat to melt the mantle. This ocean, most likely frozen now, would have been in contact with the rock core below and the surface icecap. (Which leads to the next question)
Post by: catdlr on 03/02/2015 06:33 pm
Published on Mar 2, 2015
NASA's Dawn mission will arrive at Ceres on March 6, 2015, and will be the first spacecraft to explore a dwarf planet. Ceres is the largest body in the main asteroid belt. At the time of its discovery in 1801 it was considered a planet and later demoted.
https://www.youtube.com/watch?v=LP2zbGFXyk0
Post by: zubenelgenubi on 03/02/2015 06:39 pm
Astrobiology, particularly microbes?
Europa and Enceladus display similar conditions to Ceres. Ceres is not NOW expected to have much/any liquid water, but it could have in the past.
Context with New Horizons and Pluto?
Both Ceres and Pluto are thought to be building blocks of the solar system (my comment--surviving planetesimals).
Difference--Ceres is thought to have formed at its current distance from the Sun; Pluto originated as a Kuiper Belt Object (KBO).
Similarities--both have dark surfaces and primordial components rich in water and (other) volatiles.
When New Horizons data starts returning in July 2015, there will definitely be comparing and contrasting of the two worlds.
White spots appeared lit all the way to and at the terminator?
Calculations have not yet been made of an accurate surface slope--left at that.
How do the Herschel results correlate with Dawn results?
Herschel observed water vapor release, worldwide, of 6 kg/sec. Announced January 2014.
Modeling done for distributed water vapor emanation. IR spectrography of Ceres' limb is possible, if still on-going. Also the fact that Dawn is there and observing over an extended time.
Time evolution of the characteristics of any release will be possible due to the mission length at Ceres.
Chris Russell comments from the audience that the very bright spots do get darker as they approach the terminator, and then go out at the terminator crossing.
Post by: zubenelgenubi on 03/02/2015 07:09 pm
Using trajectory to determine Ceres' mass and structure? Will Dawn be moved lower, at any time, than the lowest science orbit?
Mass determination is already being done; it will continue through the first orbit, but substantial improvement of mass measurement will come from the lower science orbits.
Dawn will not go lower than the lowest science orbit. It will stay there through end of mission. This orbit is stable on the order of hundreds of years (my comment--this orbit is intended to maintain quarantine).
How has the journey affected the team members? A rollercoaster! Wonderful working with a great team! Exciting!
Why are the bright spots inside craters?
No changes yet observed to bright spots. Other bright spots show range of structure. Some are located at the center of ray structures and in a central crater. Some are not in a crater at all.
A mention again that dust above Ceres will be searched for using the camera.
What about Ceres' thin atmosphere? This has been hypothesized since International Ultraviolet Observatory (IUE) observations over a decade ago. (my comment--hydroxide ions were observed above Ceres' north pole--publication in 1992). The Dawn team will seek confirmation of this hypothesis.
End of mission--what are the limiting parameters? Funding? Propellant?
Also what is the overall cost of the mission? $473 million to date. Dawn is a Discovery class mission--low-cost program.
The hydrazine used for attitude control is the primary limiting factor--it is used to point Dawn to Ceres and Earth. (my comment/question--the attitude control thrusters are used more often because of the failure of 2 of the 4 reaction wheels?)
There is enough hydrazine to accomplish the primary mission, but it does limit the extent of any extended mission. More likely months of extended mission, not years (they would prefer years).
About one year into the Ceres phase, they (Dawn team, NASA?) will take stock of the remaining consumables and other factors. What can Dawn do with the remaining reserves? And then execute a decision from there.
What could keep a subsurface ocean on Ceres liquid--salts? Ammonia?
Salts are most likely, ammonia less likely.
Close of the briefing!
One note from me watching the media replay--with respect to Ceres, Dawn decelerates into orbit from the dayside, then does a U-turn over the nightside, and then passes back over the dayside for the first portion of the first science orbit.
Post by: zubenelgenubi on 03/02/2015 07:24 pm
RELEASE 15-027
NASA Spacecraft Nears Historic Dwarf Planet Arrival
Ceres rotates in this sped-up movie comprised of images taken by NASA's Dawn mission
Ceres rotates in this sped-up movie comprised of images taken by NASA's Dawn mission during its approach to the dwarf planet. The images were taken on Feb. 19, 2015, from a distance of nearly 29,000 miles (46,000 kilometers). Dawn observed Ceres for a full rotation of the dwarf planet, which lasts about nine hours. The images have a resolution of 2.5 miles (4 kilometers) per pixel.
Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Feature Link:
Ceres Awaits Dawn..http://www.nasa.gov/jpl/dawn/pia18920/ (http://www.nasa.gov/jpl/dawn/pia18920/)
NASA’s Dawn spacecraft has returned new images captured on approach to its historic orbit insertion at the dwarf planet Ceres. Dawn will be the first mission to successfully visit a dwarf planet when it enters orbit around Ceres on Friday, March 6.
"Dawn is about to make history," said Robert Mase, project manager for the Dawn mission at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. "Our team is ready and eager to find out what Ceres has in store for us."
Recent images show numerous craters and unusual bright spots that scientists believe tell how Ceres, the first object discovered in our solar system’s asteroid belt, formed and whether its surface is changing. As the spacecraft spirals into closer and closer orbits around the dwarf planet, researchers will be looking for signs that these strange features are changing, which would suggest current geological activity.
NASA's Dawn spacecraft took these images of dwarf planet Ceres
NASA's Dawn spacecraft took these images of dwarf planet Ceres from about 25,000 miles (40,000 kilometers) away on Feb. 25, 2015. Ceres appears half in shadow because of the current position of the spacecraft relative to the dwarf planet and the sun. The resolution is about 2.3 miles (3.7 kilometers) per pixel.
Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
..
http://www.nasa.gov/sites/default/files/thumbnails/image/15-027-dawn-ceres.jpg (http://www.nasa.gov/sites/default/files/thumbnails/image/15-027-dawn-ceres.jpg)
“Studying Ceres allows us to do historical research in space, opening a window into the earliest chapter in the history of our solar system,” said Jim Green, director of NASA’s Planetary Science Division at the agency’s Headquarters in Washington. “Data returned from Dawn could contribute significant breakthroughs in our understanding of how the solar system formed.”
Dawn began its final approach phase toward Ceres in December. The spacecraft has taken several optical navigation images and made two rotation characterizations, allowing Ceres to be observed through its full nine-hour rotation. Since Jan. 25, Dawn has been delivering the highest-resolution images of Ceres ever captured, and they will continue to improve in quality as the spacecraft approaches.
Sicilian astronomer Father Giuseppe Piazzi spotted Ceres in 1801. As more such objects were found in the same region, they became known as asteroids, or minor planets. Ceres was initially classified as a planet and later called an asteroid. In recognition of its planet-like qualities, Ceres was designated a dwarf planet in 2006, along with Pluto and Eris.
Ceres is named for the Roman goddess of agriculture and harvests. Craters on Ceres will similarly be named for gods and goddesses of agriculture and vegetation from world mythology. Other features will be named for agricultural festivals.
Launched in September 2007, Dawn explored the giant asteroid Vesta for 14 months in 2011 and 2012, capturing detailed images and data about that body. Both Vesta and Ceres orbit the sun between Mars and Jupiter, in the main asteroid belt. This two-stop tour of our solar system is made possible by Dawn’s ion propulsion system, its three ion engines being much more efficient than chemical propulsion.
"Both Vesta and Ceres were on their way to becoming planets, but their development was interrupted by the gravity of Jupiter,” said Carol Raymond, deputy project scientist at JPL. “These two bodies are like fossils from the dawn of the solar system, and they shed light on its origins."
Ceres and Vesta have several important differences. Ceres is the most massive body in the asteroid belt, with an average diameter of 590 miles (950 kilometers). Ceres' surface covers about 38 percent of the area of the continental United States. Vesta has an average diameter of 326 miles (525 kilometers), and is the second most massive body in the belt. The asteroid formed earlier than Ceres and is a very dry body. Ceres, in contrast, is estimated to be 25 percent water by mass.
"By studying Vesta and Ceres, we will gain a better understanding of the formation of our solar system, especially the terrestrial planets and most importantly the Earth," said Raymond. "These bodies are samples of the building blocks that have formed Venus, Earth and Mars. Vesta-like bodies are believed to have contributed heavily to the core of our planet, and Ceres-like bodies may have provided our water."
"We would not be able to orbit and explore these two worlds without ion propulsion,” Mase said. “Dawn capitalizes on this innovative technology to deliver big science on a small budget.”
In addition to the Dawn mission, NASA will launch in 2016 its Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) spacecraft. This mission will study a large asteroid in unprecedented detail and return samples to Earth.
NASA also places a high priority on tracking and protecting Earth from asteroids. NASA's Near-Earth Object (NEO) Program at the agency’s headquarters manages and funds the search, study and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. NASA is pursuing an Asteroid Redirect Mission (ARM), which will identify, redirect and send astronauts to explore an asteroid. Among its many exploration goals, the mission could demonstrate basic planetary defense techniques for asteroid deflection.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia, designed and built the spacecraft.
The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission (http://dawn.jpl.nasa.gov/mission)
For more information about Dawn, visit:
http://dawn.jpl.nasa.gov (http://dawn.jpl.nasa.gov)
For more information on OSIRIS-REx and ARM visit:
http://www.nasa.gov (http://www.nasa.gov)
-end-
Post by: pagheca on 03/03/2015 01:29 pm
We probably just have to admit there has to be some sort of calibration with respect to the environment you are viewing the image from. I think it should be possible to create an image with a grey colour bar and tell the audience that "if that bar looks mid grey to you, then this is about what Ceres would look like to someone floating in the dark above it.
I created a minimalistic, simple sketch you can download here (https://www.dropbox.com/s/ovf53l2o7jcqd2y/Slide1.png?dl=0) to give an idea to whoever is interested.
If you use a MacBook Pro Retina or a screen with a luminance of ~280 cd/m2:
(1) download the picture
(2) set screen brightness ~2 steps lower than full (this is approx.)
(3) set the image at full screen
(4) darken the room, taking care the screen stay at same brightness.
(5) if the MacBook is 15", go to a distance of 3.89 m to have an idea of Ceres angular size (if not, scale accordingly, but this is irrelevant for this exercize...).
That's more or less the average luminance and size Ceres would show when the picture of the "two bright spots" was taken: ~243 cd/m2 (better to say: the central part of Ceres disk)
Of course there are no features, no "bright spots" and neither a "phase" included in this simple mock-up as screen luminance doesn't allow for this, but this is what I got including average albedo and distance from the Sun.
If you do this outside, it's quite striking that the full Moon (2500 cd/m2) is much brighter than a MacBook Pro Retina screen. However this suggests that the brightness of Ceres pictures taken by Dawn has been reduced (respect to what a human eye would actually see), rather than enhanced. And that the spots would look quite bright, although not as bright as the Moon, in those conditions (~750 cd/m2).
Post by: KelvinZero on 03/04/2015 10:31 am
Wow. I would love to be an astronaut making a low orbit pass over that bright area. Whatever it resolves to be I think it is going to look just stunning.
Ironic if after months of waiting it is in fact just a fuzzy blob though.. :)
Post by: gwiz on 03/04/2015 10:43 am
http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Water_ice_in_crater_at_Martian_north_pole
Post by: pagheca on 03/04/2015 12:19 pm
Maybe it's something like this:
http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Water_ice_in_crater_at_Martian_north_pole
Updates here:
http://www.universetoday.com/119235/bright-spots-on-ceres-likely-ice-not-cryovolcanoes/
Quote
the team will be revealing the true nature of spots with the public in real time as the spacecraft gets closer and is able to make a determination.
Thanks! Can't wait!
p.s. that's my preferred picture of Mars. I had it in a poster in glossy paper in front of my desk in my office for many years.
Post by: yg1968 on 03/06/2015 01:24 am
https://www.youtube.com/watch?v=npohVRqCYsU
Post by: Chris Bergin on 03/06/2015 02:26 am
http://www.nasaspaceflight.com/2015/03/dawn-historic-arrival-ceres/
Post by: Ben the Space Brit on 03/06/2015 10:15 am
Just a random thought - The images Dawn has already taken of Ceres are enough to produce a preliminary map of most of the surface and at a high enough resolution that all major surface features are clearly visible even if not necessarily identifiable at this stage. These results would be enough for NASA, at the time of the Ranger program or the early Pioneers, to have described the mission as an 'unqualified success'. Just shows you how far space science has come in 40 years!
Post by: pagheca on 03/06/2015 01:13 pm
I was wondering if they can and they will change exposure time to compensate for the evident saturation of the bright spots.
Post by: Chris Bergin on 03/06/2015 01:39 pm
NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000) kilometers from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 a.m. PST (7:39 a.m. EST) Friday.
Mission controllers at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California received a signal from the spacecraft at 5:36 a.m. PST (8:36 a.m. EST) that Dawn was healthy and thrusting with its ion engine, the indicator Dawn had entered orbit as planned.
"Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," said Marc Rayman, Dawn chief engineer and mission director at JPL. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home."
In addition to being the first spacecraft to visit a dwarf planet, Dawn also has the distinction of being the first mission to orbit two extraterrestrial targets. From 2011 to 2012, the spacecraft explored the giant asteroid Vesta, delivering new insights and thousands of images from that distant world. Ceres and Vesta are the two most massive residents of our solar system’s main asteroid belt between Mars and Jupiter.
The most recent images received from the spacecraft, taken on March 1 show Ceres as a crescent, mostly in shadow because the spacecraft's trajectory put it on a side of Ceres that faces away from the sun until mid-April. When Dawn emerges from Ceres' dark side, it will deliver ever-sharper images as it spirals to lower orbits around the planet.
"We feel exhilarated," said Chris Russell, principal investigator of the Dawn mission at the University of California, Los Angeles (UCLA). "We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives."
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
Post by: Chris Bergin on 03/06/2015 02:09 pm
DAWN SPACECRAFT ENTERS ORBIT AROUND CERES,
THE LARGEST OBJECT IN THE MAIN ASTEROID BELT
Orbital ATK-Designed and -Built Spacecraft Reveals Mysteries
of the Solar System
Dawn Begins Next Phase of Multi-Billion Mile Interplanetary Mission
(Dulles, Virginia, 6 March 2015) – Orbital ATK, Inc. (NYSE: OA), a global leader in aerospace and defense technologies, today announced a major milestone in a deep space exploration mission aimed at uncovering the mysteries of the solar system. NASA’s Dawn spacecraft has arrived at and is now orbiting the dwarf planet Ceres. Dawn, designed and built by Orbital ATK, accomplished this feat with the innovative use of solar electric ion propulsion, the world’s most advanced and efficient space propulsion technology. Located in the main asteroid belt between Mars and Jupiter, Ceres is the largest unexplored world of the inner solar system. Now in its eighth year of a nearly nine-year-long mission, Dawn has already advanced human understanding of planetary formation by giant leaps with the data it has returned over the last four years.
“Orbital ATK’s flight-proven technology and extensive space systems experience played key roles in building the Dawn spacecraft and integrating the ion propulsion system provided by the Jet Propulsion Laboratory,” said Frank Culbertson, president of Orbital ATK’s Space Systems Group. “This technology is revolutionizing solar system exploration and made Dawn’s historic journey to two planetary bodies possible. More than a decade ago, we committed to developing this spacecraft in an innovative way to assure that it was reliable and affordable. To see Dawn enter into this exciting science phase in fully functional status after seven-and-a-half years and several billion miles of deep-space journey is a testament to the design and workmanship skills of the JPL/Orbital ATK team.”
Launched from Cape Canaveral in September 2007, Dawn has been traveling toward Ceres since its September 2012 departure from Vesta, the second most massive object in the main asteroid belt and the first destination on this two-stop planetary mission. The spacecraft spent nearly 14 months orbiting and mapping Vesta, returning more than 30,000 images and other measurements of the protoplanet.
Beginning in January, Dawn has returned increasingly sharper images of Ceres, showing a heavily cratered surface with multiple intriguing, bright features. Dawn’s image quality now substantially exceeds the best available from the ground-based W.M. Keck Observatory and NASA's Hubble Space Telescope. By later this year, in its closest orbit around Ceres, Dawn will return images more than 800 times the resolution of Hubble. The images will provide mission scientists with a treasure trove of data to understand how Ceres evolved so differently from Vesta.
“The Dawn mission is the world’s first chance to get an up-close look at two bodies, which date back to the formation of the solar system, but evolved very differently,” said Mike Miller, Orbital ATK vice president, Science and Environmental Programs, Civil and Defense Satellite Division. “Ceres is thought to contain substantial water, perhaps up to 27 percent of its mass, a quantity roughly equivalent to the fresh water on Earth. It is expected to be mostly in the form of ice, but there may also be a liquid subsurface ocean. Dawn’s detailed image and compositional data will help us understand this very exciting prospect.”
Orbital ATK’s Space Systems Group designed and built Dawn at the company’s facilities in Dulles, Virginia. Measuring 65 feet in length and weighing nearly 2,700 pounds at launch, Dawn incorporated features of Orbital ATK’s Earth science and commercial communication spacecraft technology.
Dawn's mission is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. The University of California at Los Angeles (UCLA) is responsible for overall Dawn mission science. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
About Orbital ATK
Orbital ATK is a global leader in aerospace and defense technologies. The company designs, builds and delivers space, defense and aviation systems for customers around the world, both as a prime contractor and merchant supplier. Its main products include launch vehicles and related propulsion systems; missile products, subsystems and defense electronics; precision weapons, armament systems and ammunition; satellites and associated space components and services; and advanced aerospace structures. Headquartered in Dulles, Virginia, Orbital ATK employs more than 12,000 people in 20 states across the U.S. and in several international locations. For more information, visit www.orbitalatk.com.
Post by: Ben the Space Brit on 03/06/2015 02:32 pm
Well done to all the team who have brought Dawn so far. Special congratulations those who kept on pushing and believing even after a short-sighted space agency tried to cancel the program! Here's looking forward to a year or more of science and surprises at Ceres!
Post by: JasonAW3 on 03/06/2015 02:42 pm
Almost like they are lit from within.
Post by: JasonAW3 on 03/06/2015 02:44 pm
I, for One, Welcome Our New Ceresian Overlords. Thank you.
Be careful what you ask for.
Yeah... that was a joke.
I'm betting subsurface ice, melted by a recent impact, upwelling and freezing on the surface.
You never know... Could be a failed alien generation ship...
Post by: Star One on 03/06/2015 03:07 pm
Orbital can certainly pat themselves on the back for this one. Their launch vehicles might be more than occasionally wonky, but, when it comes to robotic spacecraft, they rightfully can consider themselves one of the top names.
Well done to all the team who have brought Dawn so far. Special congratulations those who kept on pushing and believing even after a short-sighted space agency tried to cancel the program! Here's looking forward to a year or more of science and surprises at Ceres!
Totally agree that they've done a sterling job with this craft and I would argue that it has put ion propulsion on the map as far as the wider public consciousness is concerned.
Post by: PahTo on 03/06/2015 04:07 pm
Excellent article--thanks ChrisG!
And congrats to the teams involved. Simply smashing, and an amazing set of accomplishments all the way around. Look forward to high res images and further study of this important celestial body. (we really do stand on the shoulders of giants)
Post by: ThereIWas3 on 03/06/2015 04:20 pm
Post by: Nilof on 03/06/2015 05:10 pm
Post by: Moe Grills on 03/06/2015 05:32 pm
One: Like our Moon, Ceres may have mascons (that's what they were originally called); regions or pockets of heterogeneous density that can destabilize a low altitude orbit of a spacecraft. Even a large rebound peak inside a large crater can achieve the same effect.
Two: If Ceres does have "ice volcanoes", then Dawn may end up flying through occasional extreme altitude 'clouds' of millions of microscopic ice crystals from time to time. Damage or orbital decay may result.
I agree that they might not be likely, but the possibility is still there.
Post by: LouScheffer on 03/06/2015 06:53 pm
It is interesting that both Hayabusa-1 and Dawn have suffered from multiple reaction wheel failures. Hayabusa-2 has one additional wheel as insurance. I wonder if there is some common failure mechanism on these things. Hasn't ISS had trouble with its wheels too?The story I heard is that you can get reaction wheels for roughly 10^5 dollars (with mechanical bearings) and 10^6 dollars (non-contact magnetic bearings). Science missions are always pressed for money and have to use the cheaper models.
Post by: redliox on 03/06/2015 06:55 pm
Reaction wheels are indeed fragile components. You're looking at a system of high speed moving parts that have to work continuously for years. Of course there's going to be issues in the long run.
Aside from just running out of both types of fuel the reaction wheels are my concern too. Still, I'm willing to bet Dawn may operate just fine at Ceres for a solid year before further issues pop up. We'll certainly have some decent preliminary maps of the mother-of-all-asteroids well before Dawn winds down for good. Aside from figuring out what the bright spots are, I think pinning down how much of Ceres is ice versus rock will be vital since it may represent the planetesimals that formed gas giants and seeded Earth with water.
Post by: mcgyver on 03/07/2015 09:36 am
I know it's got to be a trick of reflectivity and the camera set up, but everytime I see those two bright spots in that crater, I keep thinking on how much they look like huge doorways.They say they're not going to release any more images till april because Dawn is currently orbiting darks side and there's anything to see.
Almost like they are lit from within.
Wouldn't it be cool if there was actually something in photos shot to dark side? :-) We already have one picture of the bright spot still visible when entering dark side!
Post by: jspampin on 03/08/2015 11:41 am
For Dawn's big day - by Chris Gebhardt:
http://www.nasaspaceflight.com/2015/03/dawn-historic-arrival-ceres/
Great article, very informative about the history of the mission.
I noticed two small things that if possible might be good to update in the last section (Orbital Insertion and initial operations). There is a tense issue in the first sentence (likely due to a missed update when converting the article after the event occurred?). More importantly, it might be good to add the date of the insertion, currently only the time that the signal is received is referenced.
I hope this is not viewed as a criticism, it is meant only as suggestions for improvement. Thanks as always for the hard work of all who contribute to this site.
Post by: RotoSequence on 03/15/2015 10:05 am
Utilizing data from ftp://naif.jpl.nasa.gov/pub/naif/DAWN/misc/ceres/ , this rather interesting height-map was produced and posted at unmannedspaceflight (hopefully I'm not hilariously mistaken about it being a height map).
The topography of the bright spots region seems particularly unusual.
Post by: clongton on 03/15/2015 11:44 am
Post by: Blackstar on 03/15/2015 07:28 pm
They look like - bubbles.
Domes covering an alien base.
Post by: Star One on 03/16/2015 11:57 am
They look like - bubbles.
Domes covering an alien base.
Arrggh it's the Mysterions after all.
Post by: NovaSilisko on 03/16/2015 02:56 pm
Post by: notsorandom on 03/16/2015 05:00 pm
Utilizing data from ftp://naif.jpl.nasa.gov/pub/naif/DAWN/misc/ceres/ , this rather interesting height-map was produced and posted at unmannedspaceflight (hopefully I'm not hilariously mistaken about it being a height map).I used that elevation map to make a hillshade. It may help some features become more noticeable.
The topography of the bright spots region seems particularly unusual.
Post by: clongton on 03/16/2015 05:42 pm
Post by: RotoSequence on 03/16/2015 07:07 pm
Please don't laugh (well maybe) but for those of us familiar with making pancakes, it seriously looks like the surface of a pancake after the outgassing has just completed before you flip it. That suggests to me that at some point in her distant past Ceres may have been outgassing thru a still plastic surface, before cooling and solidifying. Do we have any sense of scale for those features? They look like craters but not like they were formed by impacts. They look like the crater remains of outgassing.
Those would be some massive bubbles of gas, and a rather elastic surface. :P
Post by: notsorandom on 03/16/2015 07:16 pm
Please don't laugh (well maybe) but for those of us familiar with making pancakes, it seriously looks like the surface of a pancake after the outgassing has just completed before you flip it. That suggests to me that at some point in her distant past Ceres may have been outgassing thru a still plastic surface, before cooling and solidifying. Do we have any sense of scale for those features? They look like craters but not like they were formed by impacts. They look like the crater remains of outgassing.If you are referring to the hill-shaded relief I posted I wouldn't try to draw too many conclusions from it. The process can exaggerate things a bit. Also the height map which was posted did not contain real elevation values. Rather it represented height in values from 0 to 255. In other words the entire difference in height between the lowest and highest point as been divided into 256 "shades". That will mute out some of the more subtle variations in slope. Furthermore the poles were lower than the equator on the elevation map. I am not sure if that is in reality true or an artifact of how the elevation was made.
That all being said I am noticing what you are talking about. The craters look more bowel like than one would expect. If that is not an artifact of the image then I think it would still be due to impacts. I'm not an expert but it would seem logical to me that a less dense material would allow an impacter to burrow deeper and thus dig out a more circular depression.
Oh also these maps have been projected onto a flat surface from a globe so that round objects will get more and more distorted as they get closer to the poles.
Post by: Lars-J on 03/16/2015 07:29 pm
Please don't laugh (well maybe) but for those of us familiar with making pancakes, it seriously looks like the surface of a pancake after the outgassing has just completed before you flip it. That suggests to me that at some point in her distant past Ceres may have been outgassing thru a still plastic surface, before cooling and solidifying. Do we have any sense of scale for those features? They look like craters but not like they were formed by impacts. They look like the crater remains of outgassing.
Eh.... no. Leave the impact crater analysis to the experts, not cooks. I don't think you understand the images that are generated.
Post by: clongton on 03/16/2015 10:36 pm
Please don't laugh (well maybe) but for those of us familiar with making pancakes, it seriously looks like the surface of a pancake after the outgassing has just completed before you flip it. That suggests to me that at some point in her distant past Ceres may have been outgassing thru a still plastic surface, before cooling and solidifying. Do we have any sense of scale for those features? They look like craters but not like they were formed by impacts. They look like the crater remains of outgassing.
Eh.... no. Leave the impact crater analysis to the experts, not cooks. I don't think you understand the images that are generated.
I don't. And I never claimed to. That's why I said it "looks like bubbles". That should have been a clue. Forgive the observation but I will stick to what it "looks like"; bubbles.
Post by: the_other_Doug on 03/17/2015 01:43 am
Sure makes Ceres look pretty rugged, overall. At the same time, there's an awful lot of local variation.
I'm sure looking forward to seeing the place from the mapping orbits. This is gonna be fun!
Post by: tea monster on 03/17/2015 10:54 am
Still holding out for a Mysteron base as the light spot! :-p
Post by: notsorandom on 03/17/2015 12:54 pm
A height map will only show the lowest parts as black and the highest as white. There is no light or shadow information. So a height map of any cratered body will look just like that.That is why I artificially added light and shadows to the DEM ;)
Still holding out for a Mysteron base as the light spot! :-p
Post by: Baranquilla on 03/17/2015 01:13 pm
A height map will only show the lowest parts as black and the highest as white. There is no light or shadow information. So a height map of any cratered body will look just like that.That is why I artificially added light and shadows to the DEM ;)
Still holding out for a Mysteron base as the light spot! :-p
Finally a topic I know something about.
Think about the irony of this. Dawn took a picture, which got made into a DEM (probably using solar angle and elevation to get the shadow out), that DEM was made into a hillshade map (adding a solar angle and elevation) :)
The 0 to 255 are actually DN (digital number) values, they are typically used for remote sensing raw data. A DEM is typically never displayed in 0 to 255 values but for this purpose it seems better than actually using a height (there is no sea level or any reference point).
Also DEM stands for Digital Elevation Model not map. DTM or Digital Terrain Model is a better term here I suppose.
Post by: RotoSequence on 03/17/2015 08:15 pm
https://twitter.com/Laurent_Montesi/status/577830420697387008
Quote
#LPSC2015 #Ceres Bright spot in center of basin, seen even above rim, so believe it's outgassing (needs higher res to get spectral info)
https://twitter.com/MonicaGrady/status/577830943995621376
Quote
Icy plume possibly seen on limb of Ceres. Exciting! #LPSC2015
Post by: dodo on 03/18/2015 04:11 am
Post by: clongton on 03/18/2015 09:33 am
Quote#LPSC2015 #Ceres Bright spot in center of basin, seen even above rim, so believe it's outgassing (needs higher res to get spectral info)
Ha! *outgassing*
Post by: Star One on 03/18/2015 10:27 am
Bright spots on Ceres could be active ice.
Quote
A pair of bright spots that glimmer inside an impact crater on the asteroid Ceres, mystifying scientists, could be coming from some kind of icy plume or other active geology.
New images from NASA’s Dawn spacecraft show the spots, known as ‘feature number 5’, at changing angles as the asteroid rotates in and out of sunlight. The pictures reveal the spots even when they are near the edge of Ceres, when the sides of the impact crater would normally block the view of anything confined to the bottom. The fact that something is visible at all suggests that the feature must rise relatively high above the surface.
http://www.nature.com/news/bright-spots-on-ceres-could-be-active-ice-1.17139
Post by: Ben the Space Brit on 03/18/2015 12:13 pm
Quote#LPSC2015 #Ceres Bright spot in center of basin, seen even above rim, so believe it's outgassing (needs higher res to get spectral info)
Ha! *outgassing*
Outgassing! COOL! (*cough* If verified.) I think that means we can state that the 'subsurface ocean' is much closer to being proven!
This definitely goes with the suggestion that the bright spots are dome-shaped. Specifically, look at the configuration of the sulphur fountains on Io - Lacking any significant atmosphere to affect their trajectory or energy, they form near-perfect dome-shaped objects. So, a dome-shaped bright spot would be exactly what we would expect a LH20 fountain on Ceres to look like!
This 'rock' is just getting better and more interesting all the time!
Post by: kevin-rf on 03/18/2015 12:28 pm
Active ice volcanoes would be most interesting!
Post by: Ben the Space Brit on 03/18/2015 12:49 pm
Quote
From what little data we have so far, they're beginning to look like Cryovolcanoes - volcano-like objects that release near-icy liquids (generally water at this distance from the Sun).
My suggested mechanism: It's possible that the deeper, newer impactors fractured the icy sub-crust over the subsurface ocean. Water is venting out when the fissure is exposed to the sun; when the vent is turned away, the surface cools enough that the vent forms a thin 'scab' of ice. This would explain the variation of brightness tied to Ceres's rotation. The vent is only active when the sun melts the 'scab', allowing water to start sublimating and, evidently, violently, possibly indicating rapid solar heating of the water.
It is likely that the fracture slowly freezes over and narrows over time before finally sealing over completely (this would not necessarily be over geological time-scales but certainly over many thousand years). Once the vent is sealed, the darker surface regolithic dust will start to filter down onto the crater floor, covering over the brighter 'spot' of exposed water ice, because there would no longer be any outgassing to blow the dust away. This is why other craters have dimmer bright spots.
If I'm right then the brightness of the crater-floor spot is proportionate to the age of the impact crater itself. Additionally, the fact that the sun's heat seemingly causes rapid and violent heating suggests that, on geological scales, the water ice sub-crust is very thin.
Definitely a world to pencil in for a future lander, I think!
Post by: Star One on 03/18/2015 02:15 pm
Post by: kch on 03/18/2015 02:40 pm
They look like - bubbles.
Domes covering an alien base.
Hope it's not a culinary institute:
http://en.wikipedia.org/wiki/To_Serve_Man_(The_Twilight_Zone) (http://en.wikipedia.org/wiki/To_Serve_Man_(The_Twilight_Zone))
;)
Post by: tea monster on 03/18/2015 03:09 pm
Post by: Star One on 03/18/2015 04:56 pm
http://m.phys.org/news/2015-03-dawn-distant-ceres-habitability.html
Post by: mcgyver on 03/19/2015 09:12 am
It's quite low for a good view of an ice plume, geyser or what it is.
Is it technically feasible to put Dawn in such a low orbit that it will pass through the plume, once Dawn reaches its planned end-of-life? Just once would be enough. Who cares if it will reach so high speed that it will get lost in space... (better than crashing onto the surface!).
Post by: Star One on 03/19/2015 09:32 am
I read that the highest resolution Dawn cameras will ever reach is just 30 m/pixel. :( Is that a reasonable hypotesis?
It's quite low for a good view of an ice plume, geyser or what it is.
Is it technically feasible to put Dawn in such a low orbit that it will pass through the plume, once Dawn reaches its planned end-of-life? Just once would be enough. Who cares if it will reach so high speed that it will get lost in space... (better than crashing onto the surface!).
Has Dawn been sufficiently sterilised to do something like that though. I don't think it has so it would break planetary protection rules.
Post by: Quagga on 03/19/2015 12:06 pm
I read that the highest resolution Dawn cameras will ever reach is just 30 m/pixel. :( Is that a reasonable hypotesis?
It's quite low for a good view of an ice plume, geyser or what it is.
Is it technically feasible to put Dawn in such a low orbit that it will pass through the plume, once Dawn reaches its planned end-of-life? Just once would be enough. Who cares if it will reach so high speed that it will get lost in space... (better than crashing onto the surface!).
You have to actually slow down to lower your orbit. Dawn will stay in the low altitude mapping orbit for reasons of planetary protection and I don't think there is enough hydrazine left for an even lower orbit. Flying through a plume would just pose an additional risk, as Dawn doesn't have suitable instruments for such a venture.
But 30m/pixel isn't that bad. Hopefully Ceres will prove to be interesting enough, so that we don't have to wait too long for a more ambitious follow-on mission. :)
Post by: zubenelgenubi on 03/19/2015 03:52 pm
I read that the highest resolution Dawn cameras will ever reach is just 30 m/pixel. :( Is that a reasonable hypotesis?
It's quite low for a good view of an ice plume, geyser or what it is.
Is it technically feasible to put Dawn in such a low orbit that it will pass through the plume, once Dawn reaches its planned end-of-life? Just once would be enough. Who cares if it will reach so high speed that it will get lost in space... (better than crashing onto the surface!).
To quote my notes several pages earlier in this thread, taken from the Ceres arrival news briefing:
What about Ceres plumes? re: Herschel observations--water vapor production is very low. If this is localized production (as opposed to diffusely all over the surface), then there may be plumes. Dawn's instruments were not designed to look for these, but the science team will do the best that they can with the instruments aboard. The camera will look for dust in plumes via forward-scattered sunlight. (My comment--also used by Cassini at Enceladus.) The infrared spectrometer will look for water vapor via limb observations. These observations can start with the first science orbit in late April.
Same source, regarding further lowering the orbit near end-of-mission:
Will Dawn be moved lower, at any time, than the lowest science orbit?
Dawn will not go lower than the lowest science orbit. It will stay there through end of mission. This orbit is stable on the order of hundreds of years (my comment--this orbit is intended to maintain quarantine).
Post by: Lars-J on 03/29/2015 08:34 pm
Post by: RotoSequence on 03/29/2015 09:05 pm
So, has there been some sort of media blackout after entering orbit around Ceres? Nothing to report?
Dawn's still on the dark side of Ceres, and isn't scheduled to resume taking pictures until April 10th. Other than a few (probably quite interesting) pictures that continue to be held onto by the Max Planck Institute for Solar System Research, there's just not much to talk about.
Post by: Blackstar on 03/29/2015 09:52 pm
So, has there been some sort of media blackout after entering orbit around Ceres? Nothing to report?
Dawn's still on the dark side of Ceres, and isn't scheduled to resume taking pictures until April 10th. Other than a few (probably quite interesting) pictures that continue to be held onto by the Max Planck Institute for Solar System Research, there's just not much to talk about.
NASA even specifically mentioned that when they reached Ceres--they noted that the orbit meant that they would not have anything new to report for over a month.
If you think that's bad, wait until the Pluto flyby. Everybody's going to get really excited and then really mad when the images only trickle in.
Orbital mechanics, baby, orbital mechanics...
Post by: Lars-J on 03/30/2015 04:02 am
Post by: RotoSequence on 03/30/2015 04:31 am
Alright, I guess I had missed that the orbital period would be so long. But still... The lack of news is frustrating when there seems to be hints that they have some exciting data.
I hear that. I really, really want to see the photographs that show the bright spot on the left limb (relative to Dawn's RC1/2 photography) during daybreak on Ceres.
Post by: zubenelgenubi on 03/30/2015 04:33 am
(LPSC = Lunar and Planetary Science Conference)
No new observations were announced, but theories and models were discussed:
Dwarf planet Ceres might have right stuff for life
http://www.newscientist.com/article/mg22530143.800-dwarf-planet-ceres-might-have-right-stuff-for-life.html (http://www.newscientist.com/article/mg22530143.800-dwarf-planet-ceres-might-have-right-stuff-for-life.html)
The "bright spot" is one of the phenomena discussed in the article.
Post by: jacqmans on 04/07/2015 01:31 am
Dawn In Excellent Shape One Month After Ceres Arrival
Since its capture by the gravity of dwarf planet Ceres on March 6, NASA's Dawn spacecraft has performed flawlessly, continuing to thrust with its ion engine as planned. The thrust, combined with Ceres' gravity, is gradually guiding the spacecraft into a circular orbit around the dwarf planet. All of the spacecraft's systems and instruments are in excellent health.
Dawn has been following its planned trajectory on the dark side of Ceres -- the side facing away from the sun -- since early March. After it entered orbit, the spacecraft's momentum carried it to a higher altitude, reaching a maximum of 46,800 miles (75,400 kilometers) on March 18. Today, Dawn is about 26,000 miles (42,000 kilometers) above Ceres, descending toward the first planned science orbit, which will be 8,400 miles (13,500 kilometers) above the surface.
The next optical navigation images of Ceres will be taken on April 10 and April 14, and are expected to be available online after initial analysis by the science team. In the first of these, the dwarf planet will appear as a thin crescent, much like the images taken on March 1, but with about 1.5 times higher resolution. The April 14 images will reveal a slightly larger crescent in even greater detail. Once Dawn settles into the first science orbit on April 23, the spacecraft will begin the intensive prime science campaign.
By early May, images will improve our view of the entire surface, including the mysterious bright spots that have captured the imaginations of scientists and space enthusiasts alike. What these reflections of sunlight represent is still unknown, but closer views should help determine their nature. The regions containing the bright spots will likely not be in view for the April 10 images; it is not yet certain whether they will be in view for the April 14 set.
On May 9, Dawn will complete its first Ceres science phase and begin to spiral down to a lower orbit to observe Ceres from a closer vantage point.
Dawn previously explored the giant asteroid Vesta for 14 months, from 2011 to 2012, capturing detailed images and data about that body.
Dawn's mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, California, for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft.
The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More details about Dawn's trajectory are available at:
http://dawnblog.jpl.nasa.gov
More information about Dawn is online at:
http://dawn.jpl.nasa.gov
Post by: kfsorensen on 04/09/2015 01:29 am
Post by: Nilof on 04/11/2015 01:17 pm
Post by: clongton on 04/11/2015 01:57 pm
Dawn has been following its planned trajectory on the dark side of Ceres -- the side facing away from the sun -- since early March.
I don't understand this statement - what "dark side" trajectory? Isn't it orbiting the entire planet, both light and dark?
Post by: KittyMoo on 04/11/2015 02:12 pm
It will take time to go into the science orbit...
Post by: Ben the Space Brit on 04/11/2015 02:14 pm
Dawn has been following its planned trajectory on the dark side of Ceres -- the side facing away from the sun -- since early March.
I don't understand this statement - what "dark side" trajectory? Isn't it orbiting the entire planet, both light and dark?
No, it's been in an extreme elliptical orbit over the dark side. About 70-80% of the duration of the current orbit is over the dark side. That won't be fixed until the apiapsis isfinally brought down by the end of this month.
Post by: KittyMoo on 04/11/2015 02:17 pm
Very elliptical @clongtonDawn has been following its planned trajectory on the dark side of Ceres -- the side facing away from the sun -- since early March.
I don't understand this statement - what "dark side" trajectory? Isn't it orbiting the entire planet, both light and dark?
Post by: ankh on 04/11/2015 02:38 pm
shows where Dawn is right now -- you can see how it took a long, long loop path on the dark side --- it went past Ceres, was captured -- but that doesn't mean it turned right around and settled into a close circular orbit. It was captured while on its way off into the dark and its almost-escape got slower and slower and finally it stopped -- far off on the dark side -- and then began to slowly fall back toward Ceres (and the Sun, and us) from far out there in the dark. It's still doing that. It should have taken an "OpNav" (optical navigation) photograph yesterday, April 10th, from the point shown in the picture.
Post by: clongton on 04/11/2015 02:48 pm
Post by: kfsorensen on 04/11/2015 03:03 pm
Got it! Thanks. I think I was being misled by several references to Dawn being captured into "orbit". The wording threw me off. So it is "captured" but is not yet in "orbit". That will happen later as it swings back past the planet again. Thanks to all for the explanation. It makes perfect sense now.
No, it's in orbit, and has been since March 6th. At least in an orbit that will keep it going round and round the primary body. When a spacecraft's orbital energy is negative, it is in a bound orbit. In the case of Dawn that orbit was initially highly elliptical, but continued thrusting by the ion engine (what a remarkable device) has been reshaping the orbit and reducing the ellipticity steadily.
Post by: clongton on 04/11/2015 03:11 pm
Post by: Nilof on 04/11/2015 09:34 pm
https://www.youtube.com/watch?v=dtO9sck13WI
Post by: Star One on 04/13/2015 08:45 pm
http://m.bbc.co.uk/news/science-environment-32290122
JPL link.
http://www.jpl.nasa.gov/news/news.php?feature=4548
Post by: mcgyver on 04/14/2015 08:15 am
http://phys.org/news/2015-04-dwarf-planet-ceres-spawns-giant.html (http://phys.org/news/2015-04-dwarf-planet-ceres-spawns-giant.html)
Hot spot not hot? ;)
Post by: KelvinZero on 04/15/2015 09:44 am
Hot spot not hot? ;)
Dr Seuss's theory is a Juggling Jott :)
Post by: Ben the Space Brit on 04/15/2015 10:56 am
One way around it is if only fresh spots are visible at IR wavelengths. Older spots, because they are thinly covered with dusty regolith, are not. Maybe the regolith is strongly IR-absorbent or IR-emitting.
Post by: Ben the Space Brit on 04/16/2015 10:59 am
Post by: ugordan on 04/16/2015 02:47 pm
JPL have modified their simulated view of Ceres relative to Dawn (http://neo.jpl.nasa.gov/orbits/fullview2.jpg) based on their true-colour full-globe map.
That's far from true color.
Post by: Star One on 04/17/2015 06:25 am
http://www.jpl.nasa.gov/news/news.php?release=2015-133
Some analysis over at the Planetary Society.
http://www.planetary.org/blogs/emily-lakdawalla/2015/new-views-of-three-worlds.html
Post by: Nilof on 04/20/2015 11:09 pm
Post by: NovaSilisko on 04/20/2015 11:10 pm
Post by: kevin-rf on 04/20/2015 11:43 pm
The first tourist destination in Space 8)
Post by: Ben the Space Brit on 04/21/2015 10:47 am
So, they're mountains then? Or at least, they look raised above the surroundings.Ice columns rising high above the surface.
How?
1) Frozen low-pressure geysers (rate of freezing being greater than rate of evaporation)
2) Some kind of tectonic feature with ice being forced up from the sub-crust through thinner parts of the regolith (like the floor of impact craters) by internal dynamics.
Post by: kfsorensen on 04/24/2015 12:16 pm
Post by: chewi on 04/26/2015 12:23 pm
Quote
NASA's Dawn spacecraft entered into its first science orbit on Thursday, April 23, as scheduled. Following a delay in communicating a command sequence, the spacecraft briefly entered into safe mode and awaited further instructions, which were sent by mission controllers. As of early Friday, April 24, the spacecraft returned to normal operating mode and the mission team continues to prepare for science data collection.
Post by: Ben the Space Brit on 04/29/2015 09:12 pm
Post by: Nilof on 05/09/2015 05:43 pm
http://www.planetary.org/blogs/emily-lakdawalla/2015/05051006-a-weeks-worth-of-rc3-dawn-ceres.html
Post by: Star One on 05/11/2015 05:57 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19547
Still a mystery what they are.
Post by: EE Scott on 05/11/2015 06:16 pm
White spots now look to be much more resolved in this new animation.
http://photojournal.jpl.nasa.gov/catalog/PIA19547
Still a mystery what they are.
Really cool - I can't wait to learn more about those spots!
Post by: Star One on 05/11/2015 06:44 pm
Post by: IRobot on 05/11/2015 06:55 pm
Is there any location where we can get the raw data, or at least a 16bit TIFF? I can also process FITS data with my own application and try to get some more info from the details, if the image is not overexposed.
Post by: Star One on 05/11/2015 10:21 pm
Post by: hop on 05/12/2015 03:01 am
Is there any location where we can get the raw data, or at least a 16bit TIFF? I can also process FITS data with my own application and try to get some more info from the details, if the image is not overexposed.Like most missions, there is a proprietary period to allow the mission team to publish before the raw data goes on PDS (not sure what it is for Dawn, maybe 6 months?) Uncalibrated pretty pictures is all we get until then.
Post by: Blackstar on 05/12/2015 03:39 am
Is there any location where we can get the raw data, or at least a 16bit TIFF? I can also process FITS data with my own application and try to get some more info from the details, if the image is not overexposed.Like most missions, there is a proprietary period to allow the mission team to publish before the raw data goes on PDS (not sure what it is for Dawn, maybe 6 months?) Uncalibrated pretty pictures is all we get until then.
Although you're correct, I'd add two points. First, NASA's policy is not as strict as ESA's and NASA can release more data whereas ESA leaves that to the PI's. Second, there have been some cases where NASA HQ has overruled a team and released data that they felt was particularly important/noteworthy. But this is in the realm of big discoveries, not the raw data. For the most part NASA strongly respects the rights of the PI's to publish first.
Post by: Star One on 05/12/2015 08:50 am
Post by: mcgyver on 05/12/2015 05:22 pm
Post by: Star One on 05/12/2015 07:56 pm
Post by: Ben the Space Brit on 05/13/2015 01:33 pm
Post by: Star One on 05/13/2015 02:14 pm
I, personally, would normally rule out all but cometary dust-deposited microbiotic life on Ceres due to the radiation environment. Then again, I was genuinely surprised to see potential evidence of geological activity, so what do I know?
Well I was only thinking in terms of the simplest life forms. But for them alone it seems a better bet than anywhere else in the inner solar system.
Post by: meekGee on 05/13/2015 04:52 pm
This is probably pie in the sky thinking but I sometimes do wonder about the chances of some form of life being found on Ceres, aside from Earth it has more water than any other body in the inner solar system and there are indications it may have internal heating of what could be a huge ocean. It also receives a decent amount of solar energy from the Sun. To me that spells a more positive cocktail than present day Mars. Be funny if after all this looking that something turned up on a body that until recently probably a lot of the public had never heard of.
I would say it's within "possible", but I don't see why "more positive cocktail than present day Mars".
Mars is warmer, has water underground (briny, sure, but do we know that Ceres isn't?), less radiation (and underground it wouldn't matter anyway) - we basically know about the same (0) about the environment in each body more than a few feet deep - except that Mars is warmer.
To me, Ceres is the ultimate location for asteroid mining though. Build a base there (because of the water), and crash-land small asteroids on the surface. Process there, send the product back to space for use.
And besides, Fourmyle of Ceres is from there :)
Post by: the_other_Doug on 05/13/2015 07:42 pm
This is probably pie in the sky thinking but I sometimes do wonder about the chances of some form of life being found on Ceres, aside from Earth it has more water than any other body in the inner solar system and there are indications it may have internal heating of what could be a huge ocean. It also receives a decent amount of solar energy from the Sun. To me that spells a more positive cocktail than present day Mars. Be funny if after all this looking that something turned up on a body that until recently probably a lot of the public had never heard of.
I would say it's within "possible", but I don't see why "more positive cocktail than present day Mars".
Mars is warmer, has water underground (briny, sure, but do we know that Ceres isn't?), less radiation (and underground it wouldn't matter anyway) - we basically know about the same (0) about the environment in each body more than a few feet deep - except that Mars is warmer.
To me, Ceres is the ultimate location for asteroid mining though. Build a base there (because of the water), and crash-land small asteroids on the surface. Process there, send the product back to space for use.
And besides, Fourmyle of Ceres is from there :)
Then it's a good thing that Dawn's engine didn't fail halfway through it's mission, leaving it Marooned Off Vesta... :D
Post by: MarsMethanogen on 05/14/2015 02:22 pm
This is probably pie in the sky thinking but I sometimes do wonder about the chances of some form of life being found on Ceres, aside from Earth it has more water than any other body in the inner solar system and there are indications it may have internal heating of what could be a huge ocean. It also receives a decent amount of solar energy from the Sun. To me that spells a more positive cocktail than present day Mars. Be funny if after all this looking that something turned up on a body that until recently probably a lot of the public had never heard of.
Somehow I KNEW that if I waited long enough, someone would pop in with that reference on this thread.
I would say it's within "possible", but I don't see why "more positive cocktail than present day Mars".
Mars is warmer, has water underground (briny, sure, but do we know that Ceres isn't?), less radiation (and underground it wouldn't matter anyway) - we basically know about the same (0) about the environment in each body more than a few feet deep - except that Mars is warmer.
To me, Ceres is the ultimate location for asteroid mining though. Build a base there (because of the water), and crash-land small asteroids on the surface. Process there, send the product back to space for use.
And besides, Fourmyle of Ceres is from there :)
Then it's a good thing that Dawn's engine didn't fail halfway through it's mission, leaving it Marooned Off Vesta... :D
Post by: Roy_H on 05/14/2015 03:02 pm
Post by: Blackstar on 05/14/2015 04:08 pm
My theory on the bright spots. Lakes filled with uranium and thorium, a natural nuclear reaction strong enough to be self-sustaining and glowing hot without exploding like a bomb.
Sounds entirely plausible.
Post by: mcgyver on 05/15/2015 01:03 pm
Post by: bunker9603 on 05/16/2015 01:53 pm
My theory on the bright spots. Lakes filled with uranium and thorium, a natural nuclear reaction strong enough to be self-sustaining and glowing hot without exploding like a bomb.
Maybe it's veins of precious metals or a big gold/platinum field. Planetary Resources could finally have a destination. :)
Post by: clongton on 05/16/2015 03:23 pm
This is an updates thread for a serious mission, not a party thread.
Chris allows party threads for such giddy comments.
Post by: Bob Shaw on 05/16/2015 03:36 pm
This is probably pie in the sky thinking but I sometimes do wonder about the chances of some form of life being found on Ceres, aside from Earth it has more water than any other body in the inner solar system and there are indications it may have internal heating of what could be a huge ocean. It also receives a decent amount of solar energy from the Sun. To me that spells a more positive cocktail than present day Mars. Be funny if after all this looking that something turned up on a body that until recently probably a lot of the public had never heard of.
I would say it's within "possible", but I don't see why "more positive cocktail than present day Mars".
Mars is warmer, has water underground (briny, sure, but do we know that Ceres isn't?), less radiation (and underground it wouldn't matter anyway) - we basically know about the same (0) about the environment in each body more than a few feet deep - except that Mars is warmer.
To me, Ceres is the ultimate location for asteroid mining though. Build a base there (because of the water), and crash-land small asteroids on the surface. Process there, send the product back to space for use.
And besides, Fourmyle of Ceres is from there :)
Then it's a good thing that Dawn's engine didn't fail halfway through it's mission, leaving it Marooned Off Vesta... :D
Vesta Anniversary is due soon.
Post by: Star One on 05/16/2015 05:29 pm
I understand being happy that Dawn is finally at Ceres, but please stay on topic.
This is an updates thread for a serious mission, not a party thread.
Chris allows party threads for such giddy comments.
Well maybe it needs another thread then if you can disallow any kind of speculation, which I feel is only natural with such a mission. Trying to stamp on people's obvious enthusiasm is the last thing that should be happening when it comes to putting across planetary science to the public.
Post by: Blackstar on 05/16/2015 08:20 pm
I understand being happy that Dawn is finally at Ceres, but please stay on topic.
This is an updates thread for a serious mission, not a party thread.
Chris allows party threads for such giddy comments.
Well maybe it needs another thread then if you can disallow any kind of speculation, which I feel is only natural with such a mission. Trying to stamp on people's obvious enthusiasm is the last thing that should be happening when it comes to putting across planetary science to the public.
I don't think there should be another thread. The science threads are pretty low traffic and a little frivolity should not cause anybody to clutch their pearls in shock.*
I happen to think that the signal/noise ratio in this section is remarkably high, so we have nothing to worry about.
*I have a habit of going back and deleting some of my frivolous posts just to clean up the threads. I wish more people would do so, but it's not a big deal.
Post by: mcgyver on 05/19/2015 07:14 am
This is an updates thread for a serious mission, not a party thread.Actually, thread title was recently changed from just "updates" to "updates and discussion" after... discussing if a discussion thread was needed. ;) I don't agree with this choice, as I receive notifications both of updates and non-updates, but...
Post by: mcgyver on 05/19/2015 08:54 am
Quote
Dawn is using its ion engine to maneuver to its second mapping orbit, which will be 2,700 miles (4,400 kilometers) high. It will reach that altitude in early June.
During the course of the day today, Dawn’s altitude will decrease from 5,500 miles (8,900 kilometers) to 4,800 miles (7,700 kilometers).
Tomorrow the spacecraft will pause ion-thrusting to take pictures of Ceres for navigation.
Quote
May 18, 2015 - Dawn’s Complex Maneuvering Continues Smoothly
On May 16, Dawn paused ion-thrusting to observe Ceres for two hours. Navigators use the pictures to help refine the trajectory as the spacecraft winds its way down to lower altitudes. The probe collected bonus infrared and visible spectra as well.[/size]
Dawn remains on course for its complex flight from the first mapping orbit to the second. Last week, the spacecraft descended every day. After dipping down to 4,400 miles (7,100 kilometers) on May 17 and 18, now the ship is slowly ascending as it continues to reshape its orbit around the dwarf planet. It will sail up to nearly 5,200 miles (more than 8,300 kilometers) tomorrow before descending again.
(bold are mine)
http://dawn.jpl.nasa.gov/mission/status.html (http://dawn.jpl.nasa.gov/mission/status.html)
So we have some new, higher res images waiting for download/release. :)
Previous images were shot from around 13000 km, new ones from 7700 km.
Currently we have a ~2 km/pixel image:
http://www.jpl.nasa.gov/spaceimages/images/largesize/PIA19547_hires.jpg
I calculated "squared feature" of the brightspot to be 14 km wide, and small dots to be 1-2 km wide, given ~1000km diameter of Ceres and not considering it like a sphere but just like a flat circle...
I think half a distance will corrispond to double resolution (1 km/pixel), so we'll have small dots becoming large 4pixel+blur and squared feature around 30 pixel.
In the meantime, I noticed several "objects" floating around Ceres, visible in the animation (http://photojournal.jpl.nasa.gov/archive/PIA19547.gif). They look like camera defects, but why don't they appear always in same position in the frame? They move along an apparently squared path.
Post by: ugordan on 05/19/2015 09:07 am
In the meantime, I noticed several "objects" floating around Ceres, visible in the animation (http://photojournal.jpl.nasa.gov/archive/PIA19547.gif). They look like camera defects, but why don't they appear always in same position in the frame?
Why would they be fixed? The spacecraft would have to be precisely pointing nadir for Ceres to always be perfectly centered on the frame. There is always some pointing drift or other pointing constraints, actual pointing is typically reconstructed afterward from spacecraft telemetry.
What you're seeing is Ceres (originally being imaged on different areas of the detector depending on drift) being registered for a smooth animation. Hence all camera artifacts shift around.
Post by: Apollo-phill on 05/19/2015 10:12 am
Phill
Post by: RotoSequence on 05/19/2015 10:36 am
Anyway, back to updates:QuoteDawn is using its ion engine to maneuver to its second mapping orbit, which will be 2,700 miles (4,400 kilometers) high. It will reach that altitude in early June.
During the course of the day today, Dawn’s altitude will decrease from 5,500 miles (8,900 kilometers) to 4,800 miles (7,700 kilometers).
Tomorrow the spacecraft will pause ion-thrusting to take pictures of Ceres for navigation.QuoteMay 18, 2015 - Dawn’s Complex Maneuvering Continues Smoothly
On May 16, Dawn paused ion-thrusting to observe Ceres for two hours. Navigators use the pictures to help refine the trajectory as the spacecraft winds its way down to lower altitudes. The probe collected bonus infrared and visible spectra as well.[/size]
Dawn remains on course for its complex flight from the first mapping orbit to the second. Last week, the spacecraft descended every day. After dipping down to 4,400 miles (7,100 kilometers) on May 17 and 18, now the ship is slowly ascending as it continues to reshape its orbit around the dwarf planet. It will sail up to nearly 5,200 miles (more than 8,300 kilometers) tomorrow before descending again.
(bold are mine)
http://dawn.jpl.nasa.gov/mission/status.html (http://dawn.jpl.nasa.gov/mission/status.html)
So we have some new, higher res images waiting for download/release. :)
Previous images were shot from around 13000 km, new ones from 7700 km.
Currently we have a ~2 km/pixel image:
http://www.jpl.nasa.gov/spaceimages/images/largesize/PIA19547_hires.jpg
I calculated "squared feature" of the brightspot to be 14 km wide, and small dots to be 1-2 km wide, given ~1000km diameter of Ceres and not considering it like a sphere but just like a flat circle...
I think half a distance will corrispond to double resolution (1 km/pixel), so we'll have small dots becoming large 4pixel+blur and squared feature around 30 pixel.
In the meantime, I noticed several "objects" floating around Ceres, visible in the animation (http://photojournal.jpl.nasa.gov/archive/PIA19547.gif). They look like camera defects, but why don't they appear always in same position in the frame? They move along an apparently squared path.
Rotation Characterization was from an approximate altitude of 13,600 kilometers, at a resolution of 1,300 meters per pixel. If the two hours of observations were done from an altitude of 7,700 kilometers, the new pictures should be 1.766x higher resolution, which would give us ~736 meters per pixel. :)
The specks in the latest images are static features relative to each other, which suggests that they're probably lens defects.
Post by: Cinder on 05/19/2015 01:10 pm
What height would be the estimate of the "mound" that appears on the "limb" of Ceres in the attached image ?~4km, according to calcs at UMSF
Phill
http://www.unmannedspaceflight.com/index.php?showtopic=7981&st=180
Post by: Star One on 05/20/2015 09:16 pm
http://dawn.jpl.nasa.gov/multimedia/images/
Post by: Robert Thompson on 05/21/2015 07:43 am
Post by: Ben the Space Brit on 05/21/2015 08:59 am
You can find a new picture taken on May 16th on here.
The central anomaly is still washed out but the offset one is clearly a cluster of higher-reflectiveness points. The distribution seems random. I'm wondering if there is a layer of water ice or something similarly more reflective just under the floor of the crater and this crater is young enough for it to have not been excessively darkened by solar radiation.
The absence of similar anomalies elsewhere is odd, including in a few very obvious young ray craters. One possibility is that it takes a particular combination of age and crater size to expose the high-reflectivity layer. Another possibility is that this layer is not present throughout Ceres and is a recent (<1bya) meteoric deposit just in that particular region.
Post by: RotoSequence on 05/21/2015 09:21 am
You can find a new picture taken on May 16th on here.
The central anomaly is still washed out but the offset one is clearly a cluster of higher-reflectiveness points. The distribution seems random. I'm wondering if there is a layer of water ice or something similarly more reflective just under the floor of the crater and this crater is young enough for it to have not been excessively darkened by solar radiation.
The absence of similar anomalies elsewhere is odd, including in a few very obvious young ray craters. One possibility is that it takes a particular combination of age and crater size to expose the high-reflectivity layer. Another possibility is that this layer is not present throughout Ceres and is a recent (<1bya) meteoric deposit just in that particular region.
I'm partial to a foreign body hypothesis, but the distribution of bright material seems like it might be hard to explain with an impact hypothesis.
Post by: Ben the Space Brit on 05/21/2015 09:32 am
I'm partial to a foreign body hypothesis, but the distribution of bright material seems like it might be hard to explain with an impact hypothesis.
I'm not sure if it works like this but I was wondering if deposited material might, with time, 'flatten out' in Ceres's crust, generating a 'shelf' of deposited material. The floor of the crater is slightly above this layer, but smaller (currently invisible) and more recent impact events have excavated deeper and exposed parts of that area.
Post by: Cinder on 05/21/2015 10:00 am
Post by: Star One on 05/21/2015 10:12 am
Also that these bright spots seem scattered about Ceres as we get closer to it, not just the more obvious ones.
Post by: Ben the Space Brit on 05/21/2015 10:17 am
That looks like a pyramidal mountain. With something reflective on certain sides.
Soft-landed large iron/nickel body maybe?
Why-oh-why did they remove Dawn's magnetometer? This body has so many features that could have led to it being a useful instrument!
Post by: Star One on 05/21/2015 10:47 am
That looks like a pyramidal mountain. With something reflective on certain sides.
Soft-landed large iron/nickel body maybe?
Why-oh-why did they remove Dawn's magnetometer? This body has so many features that could have led to it being a useful instrument!
Don't see why this necessarily has to be an impact event of some kind, to me it's more likely to be a geographical feature that has arisen on Ceres through some process.
Post by: marseventually on 05/21/2015 04:25 pm
Post by: PahTo on 05/21/2015 04:36 pm
This thread is a shining example (sorry for the pun) of why NSF is great--thanks for the contributions.
As I watched Cinder's excellent motion-picture, the same thing struck me as what Star One posits: looks like the pyramid is an "upwelling" (or better, a geologic process) of the shiny material that is exposed in the area "below".
Post by: kevin-rf on 05/21/2015 05:27 pm
I can't wait for higher res images, and tweezers.
Post by: MattMason on 05/21/2015 06:48 pm
pyramid or pimple ;)
I can't wait for higher res images, and tweezers.
Dwarf teenaged planet Ceres is meh about your attempts at treating its cosmic acne.
These are great images and we're not even at the closest orbit as yet. Given that Ceres clearly has been in a serious cosmic brawl with meteors over the eons and came up second best, the presence of that shiny pimple looks too geologically new. Something's churning inside of that dwarf, and it ain't ale.
Post by: Star One on 05/21/2015 07:12 pm
pyramid or pimple ;)
I can't wait for higher res images, and tweezers.
Because of the low resolution it makes it look like an artificial pyramid. Just hope Sutekh isn't home.
http://www.bbc.co.uk/doctorwho/classic/episodeguide/pyramidsmars/
Post by: kevin-rf on 05/21/2015 07:32 pm
Post by: meekGee on 05/21/2015 11:26 pm
Post by: nadreck on 05/21/2015 11:29 pm
Post by: Robert Thompson on 05/22/2015 01:45 am
Not obvious like the other two rilles in the image.
Post by: meekGee on 05/22/2015 01:56 am
http://dawn.jpl.nasa.gov/multimedia/images/ (Filter for "Ceres" only)
I'm finding it hard to figure out what's where.
In this image: http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA18923
I think the pimple is on the right hand side, a little more than 1/3 of the way up.
Post by: the_other_Doug on 05/22/2015 04:09 am
I don't wanna be anywhere around when it pops...
Post by: Cinder on 05/22/2015 04:02 pm
This is like approach to Iapetus. As the images came in and everyone's expectations kept getting reshuffled. :Dpyramid or pimple ;)
I can't wait for higher res images, and tweezers.
Dwarf teenaged planet Ceres is meh about your attempts at treating its cosmic acne.
These are great images and we're not even at the closest orbit as yet. Given that Ceres clearly has been in a serious cosmic brawl with meteors over the eons and came up second best, the presence of that shiny pimple looks too geologically new. Something's churning inside of that dwarf, and it ain't ale.
Post by: Star One on 05/23/2015 06:38 pm
Post by: meekGee on 05/23/2015 07:05 pm
This is like approach to Iapetus. As the images came in and everyone's expectations kept getting reshuffled.
This is another one of those understatement thingies, right?
Post by: Star One on 05/24/2015 09:56 am
Quote
May 22, 2015 - Dawn has made good progress this week continuing to reshape its orbit around Ceres. Today the spacecraft's altitude reaches down to 3,100 miles (5,000 kilometers). Now, as earlier in the week, it will ascend slowly for a while, traveling up to 4,200 miles (6,700 kilometers) on May 24. Even as it climbs, Dawn will continue using its ion engine to maneuver to the next planned mapping orbit at 2,700 miles (4,400 kilometers).
Later today the explorer will stop ion-thrusting to take pictures of Ceres for navigation. This is the second and final photo op between mapping orbits. Dawn will resume thrusting tomorrow.
http://dawn.jpl.nasa.gov/mission/status.html
Post by: Eer on 05/24/2015 02:27 pm
Post by: Star One on 05/25/2015 10:03 am
My feeling with Ceres is that it's a geologically active world & this bright stuff is being deposited on the surface by such processes.
If this is the case then surely consideration for a follow up lander mission should not only come onto the table but be high up the list on the next decadal survey.
Post by: Blackstar on 05/26/2015 09:21 pm
If this is the case then surely consideration for a follow up lander mission should not only come onto the table but be high up the list on the next decadal survey.
Not to presuppose the next decadal survey, but I doubt that such a discovery would rate very highly in the DS. Things that rate highly in the decadal survey for flagship missions are comprehensive science missions that can accomplish science across a bunch of fields. Things that rank highly for New Frontiers missions are either comprehensive science and/or fundamental science (meaning it might answer a single big question or go to an entirely new, unexplored object). Just look at the lists of flagship and New Frontiers mission options and you'll see how that works.
However, such a discovery would form an excellent basis for a future Discovery mission proposal. Asteroid missions are perfect for Discovery, and Discovery missions are not ranked in the decadal survey. That said, there are a LOT of Discovery mission proposals, so it would have to compete against a lot of things.
Post by: Ben the Space Brit on 05/27/2015 10:48 am
Post by: Star One on 05/27/2015 11:36 am
I suspect that Ceres is going to be another one of those bodies that's going to go on planetary science's 'nice to do, lots to see' list along with Enceladus, Ganemeyde and Triton. Whether or not it will ever be seen as a priority is less clear.
Well that all depends on the data from Dawn doesn't it.:)
@Blackstar fair point but feel quite strongly that the case for a lander mission will be made by Dawn. Where that ranks amongst all the other possible lander missions, well see my first point.
Post by: baldusi on 05/27/2015 12:54 pm
Post by: Blackstar on 05/27/2015 02:02 pm
@Blackstar fair point but feel quite strongly that the case for a lander mission will be made by Dawn. Where that ranks amongst all the other possible lander missions, well see my first point.
Again, that's perfect for a Discovery class mission. It could be done within that cost cap. And in fact, that's what a bunch of scientists sitting in a smoky room at the National Academies* would say--"This can be done in Discovery, so leave it there."
In order to be justified as either a New Frontiers or flagship mission either the science has to be broad and compelling, or it has to be impossible to do within the Discovery cap, thereby requiring a New Frontiers mission. Finding thermal activity on Ceres won't qualify. Why is it any more scientifically interesting than thermal activity on lots of other bodies? It's not.
*National Academies facilities are non-smoking.
Post by: meekGee on 05/27/2015 02:45 pm
If I had to state a second target for human exploration, after Mars it probably is, in fact, Ceres. It's probably "close" in delta-v terms, its environment is relatively benign, and if it is, in fact, a big ball of water, it could become a strategic outpost.It is IMO a close second. I hope Dawn can get an idea of what the outer layer is made of, and how thick it is.
Post by: Star One on 05/27/2015 03:19 pm
@Blackstar fair point but feel quite strongly that the case for a lander mission will be made by Dawn. Where that ranks amongst all the other possible lander missions, well see my first point.
Again, that's perfect for a Discovery class mission. It could be done within that cost cap. And in fact, that's what a bunch of scientists sitting in a smoky room at the National Academies* would say--"This can be done in Discovery, so leave it there."
In order to be justified as either a New Frontiers or flagship mission either the science has to be broad and compelling, or it has to be impossible to do within the Discovery cap, thereby requiring a New Frontiers mission. Finding thermal activity on Ceres won't qualify. Why is it any more scientifically interesting than thermal activity on lots of other bodies? It's not.
*National Academies facilities are non-smoking.
Would a rover fit into a Discovery class cost cap.
Post by: NovaSilisko on 05/27/2015 03:31 pm
Would a rover fit into a Discovery class cost cap.
I don't see why not. It just depends on the capabilities you want. If it's something simple like Sojourner, certainly. Just attach it to a more capable lander - I wouldn't start surface exploration with just a rover, better to step up one thing at a time.
What are the delta-v requirements for a direct trajectory from Earth to Ceres orbit, anyway? Taking into account the large plane change required?
Post by: Star One on 05/27/2015 03:51 pm
Would a rover fit into a Discovery class cost cap.
I don't see why not. It just depends on the capabilities you want. If it's something simple like Sojourner, certainly. Just attach it to a more capable lander - I wouldn't start surface exploration with just a rover, better to step up one thing at a time.
What are the delta-v requirements for a direct trajectory from Earth to Ceres orbit, anyway? Taking into account the large plane change required?
Good point. A well targeted lander on or near some of the white surface deposits would probably do the job. Only issue I can see is that the most interesting of them, which is classed as spot 5 I believe, is inside a crater. I'm assuming this might cause additional issues in targeting the landing and power production on solar panels because of shading from the crater walls.
Post by: the_other_Doug on 05/27/2015 05:31 pm
Any Ceres lander that has mechanical, moving parts (used post-landing, anyway) will have to actively anchor to the ground. This includes rovers. So, it's not as easy as just popping a little wheeled rover down a ramp. A Ceres rover has to cling to the surface while moving along it, and I don't think that's going to be as easy to design as people might think.
Post by: MattMason on 05/27/2015 05:33 pm
When talking about Ceres landers, remember that Ceres' surface gravity is about three-hundredths of a G. If you were living in a dome on Ceres and placed your cat six feet above the floor, in mid-air, it would reach the floor in, what, ten minutes or so?
Any Ceres lander that has mechanical, moving parts (used post-landing, anyway) will have to actively anchor to the ground. This includes rovers. So, it's not as easy as just popping a little wheeled rover down a ramp. A Ceres rover has to cling to the surface while moving along it, and I don't think that's going to be as easy to design as people might think.
Reinforcing this principle, recall that the successful Rosetta mission had a lander designed to anchor itself in several ways on a light-G comet on landing--and still it bounced uncontrollably.
Post by: nadreck on 05/27/2015 05:34 pm
When talking about Ceres landers, remember that Ceres' surface gravity is about three-hundredths of a G. If you were living in a dome on Ceres and placed your cat six feet above the floor, in mid-air, it would reach the floor in, what, ten minutes or so?
Any Ceres lander that has mechanical, moving parts (used post-landing, anyway) will have to actively anchor to the ground. This includes rovers. So, it's not as easy as just popping a little wheeled rover down a ramp. A Ceres rover has to cling to the surface while moving along it, and I don't think that's going to be as easy to design as people might think.
sorry, can't let stuff like this pass, 0.03g is 30cm/s2 it will take < 4 seconds for the cat to hit the floor
Post by: baldusi on 05/27/2015 05:40 pm
Use a SEP stage. I believe that if you used the basic Dawn technology you could land something relatively small on Ceres on a Discovery budget. Specially if you get the LV outside of the budget.Would a rover fit into a Discovery class cost cap.
I don't see why not. It just depends on the capabilities you want. If it's something simple like Sojourner, certainly. Just attach it to a more capable lander - I wouldn't start surface exploration with just a rover, better to step up one thing at a time.
What are the delta-v requirements for a direct trajectory from Earth to Ceres orbit, anyway? Taking into account the large plane change required?
Post by: philw1776 on 05/27/2015 05:44 pm
When talking about Ceres landers, remember that Ceres' surface gravity is about three-hundredths of a G. If you were living in a dome on Ceres and placed your cat six feet above the floor, in mid-air, it would reach the floor in, what, ten minutes or so?
Cat hits in under 5 seconds
Post by: the_other_Doug on 05/27/2015 05:58 pm
When talking about Ceres landers, remember that Ceres' surface gravity is about three-hundredths of a G. If you were living in a dome on Ceres and placed your cat six feet above the floor, in mid-air, it would reach the floor in, what, ten minutes or so?
Any Ceres lander that has mechanical, moving parts (used post-landing, anyway) will have to actively anchor to the ground. This includes rovers. So, it's not as easy as just popping a little wheeled rover down a ramp. A Ceres rover has to cling to the surface while moving along it, and I don't think that's going to be as easy to design as people might think.
sorry, can't let stuff like this pass, 0.03g is 30cm/s2 it will take < 4 seconds for the cat to hit the floor
Okay, kewl. Still, quite a long time to wait for a wheel to recontact the ground if it bounces over a small bump.
Post by: nadreck on 05/27/2015 06:02 pm
sorry, can't let stuff like this pass, 0.03g is 30cm/s2 it will take < 4 seconds for the cat to hit the floor
Okay, kewl. Still, quite a long time to wait for a wheel to recontact the ground if it bounces over a small bump.
Yes, I would suggest a spherical rover core that can hop by retracting and extending some of maybe a dozen multi section spines radiating out from it. It can control a slow roll this way and orient its camera, but can also hop meters at a time.
Post by: Robotbeat on 05/27/2015 06:30 pm
Post by: MattMason on 05/27/2015 06:38 pm
Has anyone said cryo- volcano yet? Because cryovolcano.
Perhaps: Cryovolcano with ice lava flows, moving upward before solidifying.
I have no competency on this mechanism except that glaciers do move.
Post by: Star One on 05/27/2015 06:41 pm
Has anyone said cryo- volcano yet? Because cryovolcano.
Could bacteria exist in that kind of system?
Post by: llanitedave on 05/27/2015 08:28 pm
Has anyone said cryo- volcano yet? Because cryovolcano.
Could bacteria exist in that kind of system?
Certain species could, if there's a way to keep at least some of the water liquid, and if there's enough carbon and nitrogen, etc. available, which I'm sure there is. The real question on any of these bodies is not whether life could survive, it's whether life could originate.
Post by: Eer on 05/27/2015 10:04 pm
sorry, can't let stuff like this pass, 0.03g is 30cm/s2 it will take < 4 seconds for the cat to hit the floor
Okay, kewl. Still, quite a long time to wait for a wheel to recontact the ground if it bounces over a small bump.
Yes, I would suggest a spherical rover core that can hop by retracting and extending some of maybe a dozen multi section spines radiating out from it. It can control a slow roll this way and orient its camera, but can also hop meters at a time.
Would a collection of Hall thrusters, or some other microthrust propulsion and orientation mechanism be better for getting around? Sure, you'd like to be able to anchor yourself for grinding / drilling / chipping samples, but I'm not sure using short solenoid rods to bounce you around makes as much sense as "flying" low over the surface from place to place. AI pilots should be up to that by that time, and if not - better reason to send a pilot along to reduce control feedback latencies.
Post by: nadreck on 05/27/2015 10:15 pm
sorry, can't let stuff like this pass, 0.03g is 30cm/s2 it will take < 4 seconds for the cat to hit the floor
Okay, kewl. Still, quite a long time to wait for a wheel to recontact the ground if it bounces over a small bump.
Yes, I would suggest a spherical rover core that can hop by retracting and extending some of maybe a dozen multi section spines radiating out from it. It can control a slow roll this way and orient its camera, but can also hop meters at a time.
Would a collection of Hall thrusters, or some other microthrust propulsion and orientation mechanism be better for getting around? Sure, you'd like to be able to anchor yourself for grinding / drilling / chipping samples, but I'm not sure using short solenoid rods to bounce you around makes as much sense as "flying" low over the surface from place to place. AI pilots should be up to that by that time, and if not - better reason to send a pilot along to reduce control feedback latencies.
Hall thrusters are 3 - 4 orders of magnitude too small a thrust to be used. They would be appropriate for bodies that are under 10km across at a first approximation.
I don't see an objection to having the craft pogo around at speeds of around 1m/s, or roll at speeds measured in cm/s using solenoids. The computer controls for that would be straight forward to design and adaptive to a lot of different terrains. They could, if the vehicle were oriented wrong at a specific target location hop back and roll forward again to the correct orientation.
Post by: rpapo on 05/27/2015 11:03 pm
Yes, I would suggest a spherical rover core that can hop by retracting and extending some of maybe a dozen multi section spines radiating out from it. It can control a slow roll this way and orient its camera, but can also hop meters at a time.Sounds like a sea urchin, though it wouldn't be able to use suction at the tips to adhere to the surface...
Post by: meekGee on 05/27/2015 11:16 pm
The problem with minuscule gravity is that whenever you hit a bump, forward motion creates an upwards force that's greater than your weight, and you end up jumping anyway. Instead of fighting against it, use it.
A controlled pogo kicker, that it also an energy dissipating landing leg, and you can move around at high speed and with minimal wear.
Post by: Blackstar on 05/28/2015 12:41 am
An alternative is to fly something like OSIRIS-REx and use a sampler arm to touch instruments to the surface or simply to grab samples at several locations and bring them back while the spacecraft hovers above the surface and can therefore hop around to several locations. That technology is developed and will be proven in a few more years. If you're going to do something in a complex, never-before-done manner, you better have a really good reason for doing so.
Post by: NovaSilisko on 05/28/2015 02:06 am
You all seem pretty intent on finding the most complex way to do a lander mission.
An alternative is to fly something like OSIRIS-REx and use a sampler arm to touch instruments to the surface or simply to grab samples at several locations and bring them back while the spacecraft hovers above the surface and can therefore hop around to several locations. That technology is developed and will be proven in a few more years. If you're going to do something in a complex, never-before-done manner, you better have a really good reason for doing so.
To me at least, that sounds more complicated than a pathfinder-style approach of lander+simple rover, since you now have to coordinate a number of powered landings in a non-negligible gravitational field. Experience gained with OSIRIS-REx doesn't strike me as particularly applicable given it's dealing with, by comparison, effectively no gravity.
Post by: Blackstar on 05/28/2015 02:25 am
To me at least, that sounds more complicated than a pathfinder-style approach of lander+simple rover, since you now have to coordinate a number of powered landings in a non-negligible gravitational field. Experience gained with OSIRIS-REx doesn't strike me as particularly applicable given it's dealing with, by comparison, effectively no gravity.
So some kind of walking, pogoing or other contraption that has to maneuver around on the surface without launching itself on an uncontrolled ballistic trajectory, and which has zero track record, makes more sense.
Hm.
Post by: NovaSilisko on 05/28/2015 02:31 am
So some kind of walking, pogoing or other contraption that has to maneuver around on the surface without launching itself on an uncontrolled ballistic trajectory, and which has zero track record, makes more sense.
Hm.
Oh, I seem to have missed the madcap ideas going on above, and thought you were talking about the idea of a rover in general. Yes, I will concede that the above ideas are indeed patently ridiculous ;)
Post by: meekGee on 05/28/2015 04:51 am
To me at least, that sounds more complicated than a pathfinder-style approach of lander+simple rover, since you now have to coordinate a number of powered landings in a non-negligible gravitational field. Experience gained with OSIRIS-REx doesn't strike me as particularly applicable given it's dealing with, by comparison, effectively no gravity.
So some kind of walking, pogoing or other contraption that has to maneuver around on the surface without launching itself on an uncontrolled ballistic trajectory, and which has zero track record, makes more sense.
Hm.
We have so little experience in working on/around low-gravity objects that it's too early to go by "proven track record". There's still a lot of value in designing for the requirements even if it's a new approach. Otherwise, you just locked yourself to the first thing that's been tried.
Look how many landing methods we tried on Mars, and still will be trying new ones.
I find the idea of a pogo lander pretty simple. At such low gravity, it might even be a "thruster pogo". It's just that a physical pogo never runs out of propellant, so can explore pretty much indefinitely.
Capacitor, solenoid, total impulse is known, what can be simpler? Don't have to pop more than a few tens of meters at a time, just keep doing it until something like a reaction wheel breaks. (you need those anyway for attitude control while "airborne")
Post by: nadreck on 05/28/2015 05:19 am
To me at least, that sounds more complicated than a pathfinder-style approach of lander+simple rover, since you now have to coordinate a number of powered landings in a non-negligible gravitational field. Experience gained with OSIRIS-REx doesn't strike me as particularly applicable given it's dealing with, by comparison, effectively no gravity.
So some kind of walking, pogoing or other contraption that has to maneuver around on the surface without launching itself on an uncontrolled ballistic trajectory, and which has zero track record, makes more sense.
Hm.
We have so little experience in working on/around low-gravity objects that it's too early to go by "proven track record". There's still a lot of value in designing for the requirements even if it's a new approach. Otherwise, you just locked yourself to the first thing that's been tried.
Look how many landing methods we tried on Mars, and still will be trying new ones.
I find the idea of a pogo lander pretty simple. At such low gravity, it might even be a "thruster pogo". It's just that a physical pogo never runs out of propellant, so can explore pretty much indefinitely.
Capacitor, solenoid, total impulse is known, what can be simpler? Don't have to pop more than a few tens of meters at a time, just keep doing it until something like a reaction wheel breaks. (you need those anyway for attitude control while "airborne")
No need for reaction wheels, just gyro or laser attitude sensing, you have a dozen beams to land radiating out from the spherical rover. I am also thinking single digits of meters at a time for hoping, rolling mode is at a speed of about 10cm/s
Post by: meekGee on 05/28/2015 06:39 am
To me at least, that sounds more complicated than a pathfinder-style approach of lander+simple rover, since you now have to coordinate a number of powered landings in a non-negligible gravitational field. Experience gained with OSIRIS-REx doesn't strike me as particularly applicable given it's dealing with, by comparison, effectively no gravity.
So some kind of walking, pogoing or other contraption that has to maneuver around on the surface without launching itself on an uncontrolled ballistic trajectory, and which has zero track record, makes more sense.
Hm.
We have so little experience in working on/around low-gravity objects that it's too early to go by "proven track record". There's still a lot of value in designing for the requirements even if it's a new approach. Otherwise, you just locked yourself to the first thing that's been tried.
Look how many landing methods we tried on Mars, and still will be trying new ones.
I find the idea of a pogo lander pretty simple. At such low gravity, it might even be a "thruster pogo". It's just that a physical pogo never runs out of propellant, so can explore pretty much indefinitely.
Capacitor, solenoid, total impulse is known, what can be simpler? Don't have to pop more than a few tens of meters at a time, just keep doing it until something like a reaction wheel breaks. (you need those anyway for attitude control while "airborne")
No need for reaction wheels, just gyro or laser attitude sensing, you have a dozen beams to land radiating out from the spherical rover. I am also thinking single digits of meters at a time for hoping, rolling mode is at a speed of about 10cm/s
I think you'd want them anyway. For example, if your launching kick didn't work out well, it might cause you to end up with angular momentum. This will make the landing problematic. Or, you might land on a rock that bounces away, leaving you re-bouncing with an unpredictable spin.
Inertia wheels can zero your momentum (well, the momentum of the body that is not them) and allow you to land. Once you're on astra-firma, you can dump the angular momentum and all is well.
Plus, you want your vehicle to be "more science, less locomotion". If it looks like a sea urchin, it makes it hard to to take pictures, collect sample, etc. Rather have a nice squat cylinder, maybe with kickers on both sides, and lots of room for sensors.
Post by: nadreck on 05/28/2015 03:22 pm
Once you're on astra-firma, you can dump the angular momentum and all is well.
Plana-firma?
Plus, you want your vehicle to be "more science, less locomotion". If it looks like a sea urchin, it makes it hard to to take pictures, collect sample, etc. Rather have a nice squat cylinder, maybe with kickers on both sides, and lots of room for sensors.
I think it makes more sense (and creates an ultimately lighter system) to have the spherical shape and plan for it to land at any attitude. The reaction wheel concept requires an awful lot of mass to stabilize the system within the few seconds it will be airborne. The spherical system to me offers more science and less locomotion than anything else we have discussed here for a light gravity body. When it lands in the wrong orientation for the sensors it needs it simply shortens legs away from target position rolls back enough to be oriented correctly and makes a smaller hop where orientation is less likely to drift from desired. I can do this indefinitely and it is never in any danger of damaging itself (barring going over cliffs) by landing in an orientation that it is not designed to absorb the landing force. It will always be resting on 3 of its 12 legs, a hop would be accomplished by gently retracting all 3 of the legs as much as needed to keep the craft stable while orienting it for the next hop then extending the legs with enough force for the short jump (max would be each leg exerting 0.5 joule per kilo of vehicle weight - for a maximum hop velocity of 1.2 m/s ).
Post by: meekGee on 05/28/2015 03:40 pm
Astro firma maybe.Once you're on astra-firma, you can dump the angular momentum and all is well.
Plana-firma?Plus, you want your vehicle to be "more science, less locomotion". If it looks like a sea urchin, it makes it hard to to take pictures, collect sample, etc. Rather have a nice squat cylinder, maybe with kickers on both sides, and lots of room for sensors.
I think it makes more sense (and creates an ultimately lighter system) to have the spherical shape and plan for it to land at any attitude. The reaction wheel concept requires an awful lot of mass to stabilize the system within the few seconds it will be airborne. The spherical system to me offers more science and less locomotion than anything else we have discussed here for a light gravity body. When it lands in the wrong orientation for the sensors it needs it simply shortens legs away from target position rolls back enough to be oriented correctly and makes a smaller hop where orientation is less likely to drift from desired. I can do this indefinitely and it is never in any danger of damaging itself (barring going over cliffs) by landing in an orientation that it is not designed to absorb the landing force. It will always be resting on 3 of its 12 legs, a hop would be accomplished by gently retracting all 3 of the legs as much as needed to keep the craft stable while orienting it for the next hop then extending the legs with enough force for the short jump (max would be each leg exerting 0.5 joule per kilo of vehicle weight - for a maximum hop velocity of 1.2 m/s ).
The sphere can land in any orientation, but can compensate for a rate of roll.
Post by: nadreck on 05/28/2015 03:53 pm
Astro firma maybe.
The sphere can land in any orientation, but can compensate for a rate of roll.
Astro <--> space?
I presume you are asking if it can compensate for a rate of roll and if so, then yes it can, by using the same mechanism it uses for its roll mode of moving around. It simply shortens the legs on the opposite side to the direction of motion and it can do this in a staged process even to change the rate at which it reduces the rate of roll.
Post by: Star One on 05/28/2015 05:02 pm
http://solarsystem.nasa.gov/news/display.cfm?News_ID=49244
Post by: nadreck on 05/28/2015 05:12 pm
New image of Ceres released.
http://solarsystem.nasa.gov/news/display.cfm?News_ID=49244
Now looking in several spots on that image I see a range of reflectivity that suggests that we are seeing through the surface coating on the side of the largest crater on the rim facing the sun on the top right side of the crater. I notice similar reflectivity on the rim of a crater within that crater and in some other spots. Are we seeing ice on those exposed bits, can we attribute any of that to some process that removes a layer of the darker surface material? To a process that selectively shelters those locations from accumulations of that layer? At 0.03 gee I can't imagine the same process that creates a talus slope at the base of a rock face, not unless there were some instability shaking up the rims, but that would break them down over time and lead to much less dramatic peaks.
Is this more reflective surface material something that itself is accumulating. Could venting/sublimation in one location end up depositing ice crystals elsewhere?
Post by: MarsInMyLifetime on 05/29/2015 05:20 am
Post by: metaphor on 05/31/2015 02:48 am
Would a rover fit into a Discovery class cost cap.
I don't see why not. It just depends on the capabilities you want. If it's something simple like Sojourner, certainly. Just attach it to a more capable lander - I wouldn't start surface exploration with just a rover, better to step up one thing at a time.
What are the delta-v requirements for a direct trajectory from Earth to Ceres orbit, anyway? Taking into account the large plane change required?
The delta-v requirement to get to Ceres is actually quite high. Ceres has a very small gravity well and no atmosphere, so a lot of delta-v is needed in order to be captured into orbit from a ballistic trajectory (4-5 km/s). It takes less delta-v to orbit a moon of Jupiter (~8 km/s from LEO) than Ceres (~10 km/s from LEO), even when not including gravity assists. For comparison, a ballistic mission to orbit Ceres would need more total delta-v than New Horizons did (~9 km/s from LEO) when being launched into a solar escape trajectory. That means an Atlas V 551 could get less mass to orbit Ceres than it could to fly by Pluto (assuming chemical propulsion). Non-chemical propulsion is required for any mission to Ceres with a significant payload.
Post by: Robotbeat on 05/31/2015 01:37 pm
Post by: ChefPat on 06/05/2015 12:46 pm
But, will it land on it's feet?When talking about Ceres landers, remember that Ceres' surface gravity is about three-hundredths of a G. If you were living in a dome on Ceres and placed your cat six feet above the floor, in mid-air, it would reach the floor in, what, ten minutes or so?
Any Ceres lander that has mechanical, moving parts (used post-landing, anyway) will have to actively anchor to the ground. This includes rovers. So, it's not as easy as just popping a little wheeled rover down a ramp. A Ceres rover has to cling to the surface while moving along it, and I don't think that's going to be as easy to design as people might think.
sorry, can't let stuff like this pass, 0.03g is 30cm/s2 it will take < 4 seconds for the cat to hit the floor
Post by: meekGee on 06/05/2015 06:36 pm
But, will it land on it's feet?When talking about Ceres landers, remember that Ceres' surface gravity is about three-hundredths of a G. If you were living in a dome on Ceres and placed your cat six feet above the floor, in mid-air, it would reach the floor in, what, ten minutes or so?
Any Ceres lander that has mechanical, moving parts (used post-landing, anyway) will have to actively anchor to the ground. This includes rovers. So, it's not as easy as just popping a little wheeled rover down a ramp. A Ceres rover has to cling to the surface while moving along it, and I don't think that's going to be as easy to design as people might think.
sorry, can't let stuff like this pass, 0.03g is 30cm/s2 it will take < 4 seconds for the cat to hit the floor
Yes, after taking 3 naps on the way.
Post by: KelvinZero on 06/05/2015 09:23 pm
Post by: Blackstar on 06/10/2015 06:46 pm
http://www.jpl.nasa.gov/spaceimages/images/largesize/PIA19568_hires.jpg
Post by: Star One on 06/10/2015 08:24 pm
http://www.jpl.nasa.gov/news/news.php?feature=4619
There looks to be at least a suggestion of a slope in there with a dark line. Whatever this is I suspect it's going to be something unique to Ceres.
Post by: Borklund on 06/10/2015 08:33 pm
http://www.jpl.nasa.gov/dawn/world_ceres/
Post by: Star One on 06/10/2015 08:34 pm
The question though what is other?
Post by: cro-magnon gramps on 06/10/2015 08:48 pm
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
Post by: Star One on 06/10/2015 08:54 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica all the way to an extreme suggestion like bioluminescent Algae. ;)
Post by: cro-magnon gramps on 06/10/2015 08:57 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica to bioluminescent algae if you catch what I mean.
Oh, I do catch what you mean, and it would put the cat amongst the pigeons, in the life sciences. ;D
Post by: nadreck on 06/10/2015 08:57 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica all the way to an extreme suggestion like bioluminescent Algae. ;)
What about just plain ice that hasn't had a chance to sublime away yet?
Post by: Star One on 06/10/2015 08:59 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica all the way to an extreme suggestion like bioluminescent Algae. ;)
What about just plain ice that hasn't had a chance to sublime away yet?
As I indicated that's entirely possible. We have a range of possibilities.
It could even be a mix of stuff.
Does Dawn have the instruments to do some kind of analysis something like this?
Post by: cro-magnon gramps on 06/10/2015 09:01 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica all the way to an extreme suggestion like bioluminescent Algae. ;)
What about just plain ice that hasn't had a chance to sublime away yet?
The problem I see with that is if you notice the merging of dots to format larger aggravates, this is an ongoing process.
Post by: Star One on 06/10/2015 09:06 pm
More seriously I hope they are taking some less overexposed images, I imagine in this orbit that's entirely possible.
Post by: nadreck on 06/10/2015 09:08 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica all the way to an extreme suggestion like bioluminescent Algae. ;)
What about just plain ice that hasn't had a chance to sublime away yet?
The problem I see with that is if you notice the merging of dots to format larger aggravates, this is an ongoing process.
Which to me argues for something that is only temporary anyway. Or we would see more of them on the surface. In a few thousand years the ice in this extrusion has sublimed away and the suspended material that remains behind makes up the "surface" in an analogous fashion to a moraine and
EDIT - strikeout and italics showing change above
Post by: cro-magnon gramps on 06/10/2015 09:14 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica all the way to an extreme suggestion like bioluminescent Algae. ;)
What about just plain ice that hasn't had a chance to sublime away yet?
The problem I see with that is if you notice the merging of dots to format larger aggravates, this is an ongoing process.
Which to me argues for something that is only temporary anyway. Or we would see more of them on the surface. In a few thousand years the ice in this extrusion has sublimed away and the suspended material that remains behind makes up the "surface" in an analogous fashion to a moraine and insulates the ice below.
Then dust covers it over and gives it the grey appearance... as good a process as any...
Post by: Star One on 06/10/2015 09:18 pm
My un-educated guess:
The bright spots have very short rays around the edges. To me this rules out impact cratering
Also because they are fuzzy and short, I am discounting volcanic origin, such as occurs on Earth.
To me it appears as a welling up without force, of a bright silica like substance. What might cause that? Perhaps subsurface water rich in that substance, which was then lost to space.
I like that theory. Though TBH it could be anything that's welling out from inside running the range from Silica all the way to an extreme suggestion like bioluminescent Algae. ;)
What about just plain ice that hasn't had a chance to sublime away yet?
The problem I see with that is if you notice the merging of dots to format larger aggravates, this is an ongoing process.
Which to me argues for something that is only temporary anyway. Or we would see more of them on the surface. In a few thousand years the ice in this extrusion has sublimed away and the suspended material that remains behind makes up the "surface" in an analogous fashion to a moraine and insulates the ice below.
Other than the fact you can see as is becoming increasingly apparent a number of other bright spots all about the surface.
Post by: cro-magnon gramps on 06/10/2015 09:28 pm
Your right that there is another spot, either forming, or being covered with grey dust. If this is an ongoing process I would think we will see transitioning spots, elsewhere as we get closer. One thing I have ruled out, is Aliens mining efforts ;D
Post by: Star One on 06/10/2015 09:31 pm
Post by: cro-magnon gramps on 06/10/2015 09:45 pm
Post by: Star One on 06/10/2015 09:57 pm
Post by: cro-magnon gramps on 06/10/2015 10:16 pm
Isn't the final orbit going to be at 240 miles.That works out about right for 375 km.... This is from JPL ( http://www.jpl.nasa.gov/news/news.php?release=2013-347 )
Dawn will make its first full characterization of Ceres later in April, at an altitude of about 8,400 miles (13,500 kilometers) above the icy surface. Then, it will spiral down to an altitude of about 2,750 miles (4,430 kilometers), and obtain more science data in its survey science orbit. This phase will last for 22 days, and is designed to obtain a global view of Ceres with Dawn's framing camera, and global maps with the visible and infrared mapping spectrometer (VIR).
Dawn will then continue to spiral its way down to an altitude of about 920 miles (1,480 kilometers), and in August 2015 will begin a two-month phase known as the high-altitude mapping orbit. During this phase, the spacecraft will continue to acquire near-global maps with the VIR and framing camera at higher resolution than in the survey phase. The spacecraft will also image in "stereo" to resolve the surface in 3-D.
Then, after spiraling down for two months, Dawn will begin its closest orbit around Ceres in late November, at a distance of about 233 miles (375 kilometers). The dance at low-altitude mapping orbit will be a long waltz -- three months -- and is specifically designed to acquire data with Dawn's gamma ray and neutron detector (GRaND) and gravity investigation. GRaND will reveal the signatures of the elements on and near the surface. The gravity experiment will measure the tug of the dwarf planet, as monitored by changes in the high-precision radio link to NASA's Deep Space Network on Earth.
At this low-altitude mapping orbit, Dawn will begin using a method of pointing control that engineers have dubbed "hybrid" mode because it utilizes a combination of reaction wheels and thrusters to point the spacecraft. Up until this final mission phase, Dawn will have used just the small thruster jets, which use a fuel called hydrazine, to control its orientation and pointing. While it is possible to explore Ceres completely using only these jets, mission managers want to conserve precious fuel. At this lowest orbit, using two of the reaction wheels to help with pointing will provide the biggest hydrazine savings. So Dawn will be spinning up two of the gyroscope-like devices to aid the thrusters.
Post by: NovaSilisko on 06/10/2015 10:17 pm
Post by: meekGee on 06/11/2015 12:10 am
This image will not cease captivating me. It looks so... strange. It doesn't look like an airless body should. The features look like they've been eroded by wind. I would've thought this was an odd picture of Mars were it not in the Ceres section.
If the layer under the outer rock is water ice, then it might be creeping on relatively short time scales, and that can cause a softening of the features, right?
Post by: Lars-J on 06/11/2015 12:52 am
Post by: ugordan on 06/11/2015 07:53 am
If they really want to see what the white spots are made of, why don't they just start exposing properly for them?
What makes you think they aren't (or that it's these very same images, deliberately stretched into clipping) and they're just not releasing them on purpose yet?
Post by: meekGee on 06/11/2015 08:07 am
There appear to be similar shapes dotted around the plateau. No ideas at the moment. But someone will earn a PHD out of this ;-) I am leaning towards Nadrecks idea of sublimating ice, leaving deposits. There are a number of depressions and colour variations. Anyone know how close we will get to Ceres.
They almost look like... dark arrows of some sort!
Post by: Star One on 06/11/2015 10:38 am
If they really want to see what the white spots are made of, why don't they just start exposing properly for them?
What makes you think they aren't (or that it's these very same images, deliberately stretched into clipping) and they're just not releasing them on purpose yet?
Sometimes I think people forgot these images are for the mission scientists to examine first.
Post by: Ben the Space Brit on 06/11/2015 11:17 am
There must be something unique about that particular crater and that particular location on Ceres. If it was anything else, there would be distinctly bright white spots in other locations.
Post by: Star One on 06/11/2015 01:14 pm
A prediction, the two bright features will turn out to be different things. Although the bright materials will be similar or identical, the actual cause for the materials being in those locations will be different.
There must be something unique about that particular crater and that particular location on Ceres. If it was anything else, there would be distinctly bright white spots in other locations.
Well there are bright spots elsewhere, just nowhere as bright so I'm not so sure it's location specific phenomena.
Post by: Patchouli on 06/11/2015 05:22 pm
Post by: meekGee on 06/11/2015 06:18 pm
A prediction, the two bright features will turn out to be different things. Although the bright materials will be similar or identical, the actual cause for the materials being in those locations will be different.
There must be something unique about that particular crater and that particular location on Ceres. If it was anything else, there would be distinctly bright white spots in other locations.
Well there are bright spots elsewhere, just nowhere as bright so I'm not so sure it's location specific phenomena.
Right - so I'd speculate the mechanism is simply more active at that crater.
If we're talking about water leeching from the subsurface and freezing, then an impact-cause fracture can explain why some craters have more of it and some less.
Post by: nadreck on 06/11/2015 06:20 pm
A prediction, the two bright features will turn out to be different things. Although the bright materials will be similar or identical, the actual cause for the materials being in those locations will be different.
There must be something unique about that particular crater and that particular location on Ceres. If it was anything else, there would be distinctly bright white spots in other locations.
Well there are bright spots elsewhere, just nowhere as bright so I'm not so sure it's location specific phenomena.
Right - so I'd speculate the mechanism is simply more active at that crater.
If we're talking about water leeching from the subsurface and freezing, then an impact-cause fracture can explain why some craters have more of it and some less.
Or more recent, with other outflows more sublimed and with a much higher percentage of suspended solids.
Post by: Star One on 06/11/2015 06:50 pm
Post by: meekGee on 06/11/2015 07:54 pm
A prediction, the two bright features will turn out to be different things. Although the bright materials will be similar or identical, the actual cause for the materials being in those locations will be different.
There must be something unique about that particular crater and that particular location on Ceres. If it was anything else, there would be distinctly bright white spots in other locations.
Well there are bright spots elsewhere, just nowhere as bright so I'm not so sure it's location specific phenomena.
Right - so I'd speculate the mechanism is simply more active at that crater.
If we're talking about water leeching from the subsurface and freezing, then an impact-cause fracture can explain why some craters have more of it and some less.
Or more recent, with other outflows more sublimed and with a much higher percentage of suspended solids.
Yup. Just as likely. So either more active, or more recent. (which statistically are similar)
To my eye, it doesn't look "impacty", except for the fact that it is centered on a crater. That's why I was thinking it is fracture related, but the fracture doesn't to happen at the same time as the impact. The impact alters the outer layer, and a million years later, maybe due to an impact somewhere else, the thinner skin at the center of the crater fractures.
But this is highly speculative. Just making up stuff that fits. Can't wait for them to go to the low orbits. Such a shame they can't land or even crash land.
Post by: PahTo on 06/11/2015 08:16 pm
Can't wait for them to go to the low orbits. Such a shame they can't land or even crash land.
No doubt. It would be nice to "blow the dust off" the bottoms of some craters of similar depth...
Post by: Lars-J on 06/11/2015 10:09 pm
If they really want to see what the white spots are made of, why don't they just start exposing properly for them?
What makes you think they aren't (or that it's these very same images, deliberately stretched into clipping) and they're just not releasing them on purpose yet?
Sometimes I think people forgot these images are for the mission scientists to examine first.
I have forgotten no such thing, I'm just hoping for more expediency and openness. This mission isn't operated at the absurd level of scientific secrecy as the Rosetta mission, but it isn't far off.
Post by: Blackstar on 06/11/2015 10:28 pm
If they really want to see what the white spots are made of, why don't they just start exposing properly for them?
What makes you think they aren't (or that it's these very same images, deliberately stretched into clipping) and they're just not releasing them on purpose yet?
Sometimes I think people forgot these images are for the mission scientists to examine first.
I have forgotten no such thing, I'm just hoping for more expediency and openness. This mission isn't operated at the absurd level of scientific secrecy as the Rosetta mission, but it isn't far off.
No, not even close. The mission PI put a lot of effort and work into developing the mission. There's a reason why they get first dibs on the data--they did the work.
Post by: Star One on 06/11/2015 10:29 pm
If they really want to see what the white spots are made of, why don't they just start exposing properly for them?
What makes you think they aren't (or that it's these very same images, deliberately stretched into clipping) and they're just not releasing them on purpose yet?
Sometimes I think people forgot these images are for the mission scientists to examine first.
I have forgotten no such thing, I'm just hoping for more expediency and openness. This mission isn't operated at the absurd level of scientific secrecy as the Rosetta mission, but it isn't far off.
You see it as secrecy they probably see it as good practice. I mean it's hardly on the scale of the delays you get with ESA.
Post by: Lars-J on 06/11/2015 11:54 pm
Sometimes I think people forgot these images are for the mission scientists to examine first.
I have forgotten no such thing, I'm just hoping for more expediency and openness. This mission isn't operated at the absurd level of scientific secrecy as the Rosetta mission, but it isn't far off.
No, not even close. The mission PI put a lot of effort and work into developing the mission. There's a reason why they get first dibs on the data--they did the work.
Sigh... I know that. No one is disputing that. Merely the time scale involved, and the policy of fast-tracking the release of important discoveries. (which has happened) But no matter, I'm sure someone will respond with the same "you don't understand they get first dibs" no matter what I write.
Post by: meekGee on 06/12/2015 12:20 am
I am sure such pictures were taken, and they are simply not being published.
Post by: Star One on 06/12/2015 07:12 am
Absolutely it is strange that we've been staring at pictures that over expose the main object of interest to the point where no detail is discernible.
I am sure such pictures were taken, and they are simply not being published.
Is that such a worry in the short term other than to the more conspiracy minded folk online & they'd probably be up in arms whatever?
Post by: meekGee on 06/13/2015 06:04 am
Absolutely it is strange that we've been staring at pictures that over expose the main object of interest to the point where no detail is discernible.
I am sure such pictures were taken, and they are simply not being published.
Is that such a worry in the short term other than to the more conspiracy minded folk online & they'd probably be up in arms whatever?
It's not a worry, I'm just trusting that the science team didn't overlook the point... These pictures exist, they chose not to publish them. Not a statement of right or wrong, just that it feel odd to keep staring at "mysterious white blob" where clearly it is not white and the images showing details exist.
Or, put another way, the two other options (Either that they didn't think of underexposing a bit, or that no matter how much they underexposed, the images still show as 100% white) are both pretty unlikely.
Post by: Star One on 06/13/2015 10:22 am
Absolutely it is strange that we've been staring at pictures that over expose the main object of interest to the point where no detail is discernible.
I am sure such pictures were taken, and they are simply not being published.
Is that such a worry in the short term other than to the more conspiracy minded folk online & they'd probably be up in arms whatever?
It's not a worry, I'm just trusting that the science team didn't overlook the point... These pictures exist, they chose not to publish them. Not a statement of right or wrong, just that it feel odd to keep staring at "mysterious white blob" where clearly it is not white and the images showing details exist.
Or, put another way, the two other options (Either that they didn't think of underexposing a bit, or that no matter how much they underexposed, the images still show as 100% white) are both pretty unlikely.
The first reason I agree is unlikely, but the second well that's not beyond the realms of possibility. Either way I'm willing to cut them some slack on this.:)
Post by: hop on 06/13/2015 06:56 pm
It's not a worry, I'm just trusting that the science team didn't overlook the point... These pictures exist, they chose not to publish them.IMO, it's likely that correctly exposed images don't actually answer the question anyway. It will probably take VIR data to be really definitive.
Post by: the_other_Doug on 06/14/2015 06:58 am
Something that relatively bright is beyond just "stop it down a little," I think. I bet they have to develop some special techniques to get good images of the brightest of the bright spots, and we may not see them really well resolved for another month or two.
Post by: meekGee on 06/14/2015 07:46 pm
Remember that the main bright spot under discussion (area 5, I think they call it) is so bright, in comparison to the rest of Ceres, that it is visible -- in fact, dominates -- the Hubble images taken all the way from Earth. The bright spot is a significant fraction of all the photons Hubble collected that were reflected by all of Ceres.
Something that relatively bright is beyond just "stop it down a little," I think. I bet they have to develop some special techniques to get good images of the brightest of the bright spots, and we may not see them really well resolved for another month or two.
Sure, but we're talking diffused reflectivity here. It's not like it's a specular reflection of the sun into the camera. I can't imagine they can't shorten the exposure enough to deal with it.
(If it was specular, then it'd be dimmer at other times, and we'd have lots of information based on the timing)
---
What would be completely awesome is that they're not publishing the under-exposed images because the details in them have varied over time.
Post by: Star One on 06/16/2015 05:08 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19573
Post by: PahTo on 06/16/2015 05:29 pm
Thanks Start One--that might not be "the crater", but it sure seems to have some highly reflective material visible. It would seem we're just "scratching the surface". :)
Post by: Blackstar on 06/17/2015 12:37 am
Post by: redliox on 06/17/2015 01:42 am
Post by: Star One on 06/17/2015 06:21 am
Post by: Blackstar on 06/17/2015 10:53 am
I assuming the science teams are still chewing over any properly exposed pictures of Spot 5 that they have.
Apparently some significant news to come out soon.
Post by: kevin-rf on 06/17/2015 01:48 pm
Anyone else spot Mickey Mouse in the corner? :-)Disney Land Ceres? Now that would be a road trip ;)
Post by: Star One on 06/17/2015 02:09 pm
I assuming the science teams are still chewing over any properly exposed pictures of Spot 5 that they have.
Apparently some significant news to come out soon.
Now you have me intrigued.:)
Post by: NovaSilisko on 06/17/2015 11:09 pm
I assuming the science teams are still chewing over any properly exposed pictures of Spot 5 that they have.
Apparently some significant news to come out soon.
You are such a tease sometimes :P
Post by: cro-magnon gramps on 06/18/2015 12:04 am
http://www.theweathernetwork.com/news/articles/whats-up-in-space-great-pyramid-of-ceres-mars-conjunction-lunar-dust-cloud/52920/
Well I guess it will grab the attention of the less informed and perhaps bring them a step closer to finding NSF!
Post by: Star One on 06/18/2015 11:06 am
The peak w/ steep angular slopes in today's #Ceres image is about 3 miles (5 km) high http://go.nasa.gov/1GP9ogi
There is also bright material in this image but, much like the bright material found elsewhere on Ceres, it is mysterious
Post by: Blackstar on 06/18/2015 01:11 pm
Post by: Apollo-phill on 06/18/2015 01:43 pm
Phill
Post by: kevin-rf on 06/18/2015 02:02 pm
Post by: ehb on 06/18/2015 02:21 pm
Better images of the pyramid.Clearly the result of a geologic process. ;)
Although it would be highly unusual could the pyramidal shaped hill be a "salt dome" ?
Phill
On a more serious note, I am also curious to read informed discourse on the possible formations of the rare (singular?) peak.
From what I google, hills - at least on earth - are never so high as 5 km, and it seems hills are mostly (always?) formed by erosion.
For mountains, according to "grain of salt" wikipedia, include fold (tectonic plate collision or subduction), block (via faults) and volcanic.
On a body such as Ceres, only volcanic seems to make sense to me & correlation with the "relatively white stuff" seems a reasonable hypothesis.
Very interesting place, Ceres...
-ehb
Post by: Star One on 06/18/2015 03:07 pm
https://en.m.wikipedia.org/wiki/Shield_volcano
Also the slopes of it seem to be covered in the white material.
Ceres could do with a InSight type mission by the looks of it.
Post by: ehb on 06/18/2015 03:34 pm
Could it be a shield volcano?
https://en.m.wikipedia.org/wiki/Shield_volcano
Also the slopes of it seem to be covered in the white material.
Ceres could do with a InSight type mission by the looks of it.
Could be, but I do not expect with molten rock.
Possibly a shield cryovolcano (https://en.wikipedia.org/wiki/Cryovolcano) with the white material acting as magma.
Post by: Star One on 06/18/2015 03:56 pm
Could it be a shield volcano?
https://en.m.wikipedia.org/wiki/Shield_volcano
Also the slopes of it seem to be covered in the white material.
Ceres could do with a InSight type mission by the looks of it.
Could be, but I do not expect with molten rock.
Possibly a shield cryovolcano (https://en.wikipedia.org/wiki/Cryovolcano) with the white material acting as magma.
The big question then would be if Ceres was geologically active in the past is it still active and if it is what are the processes driving this activity?
Post by: ehb on 06/18/2015 03:57 pm
Post by: meekGee on 06/18/2015 04:26 pm
Better images of the pyramid.:)
Now looking for the Sphinx?
Post by: Lee Jay on 06/18/2015 04:52 pm
Better images of the pyramid.Clearly the result of a geologic process. ;)
Looks more like the result of a geometric process to me.
Post by: Star One on 06/18/2015 04:53 pm
The main crater looks quite old as there has been subsequent cratering of it, but there looks to be further white material leading from that peak.
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19575
Post by: nadreck on 06/18/2015 05:44 pm
Today's image. Is that an impact peak near the middle or something else?
The main crater looks quite old as there has been subsequent cratering of it, but there looks to be further white material leading from that peak.
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19575
Instead of being as old as you are assuming, is it possible that it is not an impact crater by a cryocaldera depression?
Post by: Star One on 06/18/2015 06:59 pm
Today's image. Is that an impact peak near the middle or something else?
The main crater looks quite old as there has been subsequent cratering of it, but there looks to be further white material leading from that peak.
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19575
Instead of being as old as you are assuming, is it possible that it is not an impact crater by a cryocaldera depression?
By there seems to be common occurrence of features that are craters on Ceres having centre peaks.
Post by: notsorandom on 06/18/2015 07:55 pm
Today's image. Is that an impact peak near the middle or something else?The lighting is from the north which is where the peak looks to have the white area. The lighting angle is somewhat low as can be seen by the shadows on the crater wall. Some of the higher reflectance of the peak relative the the surroundings may be because the slope of the peak is facing the sun in a more head on direction.
The main crater looks quite old as there has been subsequent cratering of it, but there looks to be further white material leading from that peak.
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19575
Post by: Star One on 06/18/2015 08:22 pm
Post by: RotoSequence on 06/19/2015 06:16 am
I assuming the science teams are still chewing over any properly exposed pictures of Spot 5 that they have.
Apparently some significant news to come out soon.
Oh? Any word on the time frame? :o
Post by: Star One on 06/19/2015 04:15 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19576
Interesting that long bright white streak in the upper left of the image. Not sure if that's Spot 5 from a different angle or another feature.
Either way it looks from that angle like a lake of stuff, but that might just be a trick of the angle the photo was taken at.
Post by: Cinder on 06/19/2015 05:00 pm
This page (http://laps.noaa.gov/albers/sos/sos.html#Ceres) has a recently updated composite cylindrical map of Ceres, where you can recognize the feature centered on in PIA19575. Those three small higher-contrast craters near the rim (above "PIA" in crop attached below) point almost to Spot 5's direction from the central peak. Looking at the features around PIA19575's area, you can guess that the distance also fits, from 19575's large crater feature to what looks like Spot 5 on the horizon in 19576.
Post by: RotoSequence on 06/19/2015 05:05 pm
Today's image of Ceres.
http://photojournal.jpl.nasa.gov/catalog/PIA19576
Interesting that long bright white streak in the upper left of the image. Not sure if that's Spot 5 from a different angle or another feature.
Either way it looks from that angle like a lake of stuff, but that might just be a trick of the angle the photo was taken at.
The Dawn Twitter account confirms that it is Feature 5.
https://twitter.com/NASA_Dawn/status/611936137796452352
Quote
A glimpse of that mysterious bright material on #Ceres to finish off the week http://go.nasa.gov/1L6Ea6d
Post by: Star One on 06/21/2015 11:14 am
The rest of the landscape looks like a mix between the Moon & Mars.
Post by: rubtest on 06/21/2015 12:13 pm
I have noticed that many small craters "south" to white spot S5 have a distinctive central peak , also the small craters.
I think this is due to a crust which became liquid or plastic after meteorite impact and the re-bounce shock creates a central peak if the crust solidifies quickly ( like lava).
but by small craters around the crater with spot S5 the central peaks of the craters are very rounded and shallow.
(it might be only illumination optic effect).
Maybe the rocky crust there is so thin that the meteorites hit actually directly an underground sea.
In case of spot s5 ( middle of a 90 km crater) the shock wave that could created the central peak in normal solid crust blew the almost liquid central peak away giving an wide ( few kilometer) open glimpse to the frozen (?) water reservoir below.
sounds plausible in spite of the several "maybe"?
greetings
rubtest
Post by: Star One on 06/21/2015 01:45 pm
Post by: Bob Shaw on 06/21/2015 02:52 pm
The crust of Ceres appears to be reasonably strong, unlike the plastic, mobile surface of Europa, or even parts of Ganymede - or Enceladus. It allows for old, jumbled terrain, well-sprinkled with LHB impacts - much like the Earth's Moon. The morphology of individual craters is also consistent with a very solid composition - we see no rampart craters, no flow features, nothing like a mini-Europa might have. A large proportion of craters on rocky worlds above about 100km have central mountains, many have flat floors comprised of debris and impact melts, though obviously impacts into a volatile-rich body will create different crater forms (what was once solid 'rock' (ice and rock) may simply evaporate when heated). Again, this isn't about seeing an underground ocean.
We may see more interesting features as Dawn gets closer, but thus far the only surprises are the bright patches, which are unlike anything seen before. Pre-launch, in the first round of planning for Dawn before it was cancelled, Ceres was described as being a 'mini-Mars', complete with dried-up river valleys and clay deposits. My money now would be on it being a 'mini-Callisto', without the benefit of Jovian tidal heating.
I'd have preferred a small Mars!
Post by: Star One on 06/21/2015 05:32 pm
Quote
Intriguingly, scientists announced the discovery of water-vapor emission from Ceres — which may also possess a subsurface ocean — earlier this year.
Ceres' plumes may or may not be evidence of internal heat, Li said. For example, they may result when water ice near Ceres' surface is heated by sunlight and warms enough to sublimate into space.
"Right now, we just don't know much about the outgassing on Ceres," Li said.
http://m.space.com/28068-dwarf-planet-ceres-life-dawn-mission.html
Post by: Bob Shaw on 06/21/2015 05:35 pm
Actually there is indications that Ceres may still have an internal heat source.QuoteIntriguingly, scientists announced the discovery of water-vapor emission from Ceres — which may also possess a subsurface ocean — earlier this year.
Ceres' plumes may or may not be evidence of internal heat, Li said. For example, they may result when water ice near Ceres' surface is heated by sunlight and warms enough to sublimate into space.
"Right now, we just don't know much about the outgassing on Ceres," Li said.
http://m.space.com/28068-dwarf-planet-ceres-life-dawn-mission.html
Your quote supports either view, but provides no mechanism for a heat source, sorry.
What a pity there's no magnetometer!
Post by: Star One on 06/21/2015 06:29 pm
Actually there is indications that Ceres may still have an internal heat source.QuoteIntriguingly, scientists announced the discovery of water-vapor emission from Ceres — which may also possess a subsurface ocean — earlier this year.
Ceres' plumes may or may not be evidence of internal heat, Li said. For example, they may result when water ice near Ceres' surface is heated by sunlight and warms enough to sublimate into space.
"Right now, we just don't know much about the outgassing on Ceres," Li said.
http://m.space.com/28068-dwarf-planet-ceres-life-dawn-mission.html
Your quote supports either view, but provides no mechanism for a heat source, sorry.
What a pity there's no magnetometer!
My point being jumping to a conclusion in one direction or the other at this stage is probably not a good idea.
Post by: meekGee on 06/21/2015 06:45 pm
Actually there is indications that Ceres may still have an internal heat source.QuoteIntriguingly, scientists announced the discovery of water-vapor emission from Ceres — which may also possess a subsurface ocean — earlier this year.
Ceres' plumes may or may not be evidence of internal heat, Li said. For example, they may result when water ice near Ceres' surface is heated by sunlight and warms enough to sublimate into space.
"Right now, we just don't know much about the outgassing on Ceres," Li said.
http://m.space.com/28068-dwarf-planet-ceres-life-dawn-mission.html
Your quote supports either view, but provides no mechanism for a heat source, sorry.
What a pity there's no magnetometer!
In your previous post, you discounted radioactive decay. Is this based on some measurement, or on an estimate for how much material could have been there to begin with? (From an ISRU point of view, water ice is practically as good as water of course.)
The white spots are getting curiouser since no obvious answer came up so far.
There are various theories - can we rule out any of them based on the fact that from data acquired so far has not yielded a clear conclusion?
Is there enough resolution to already read the white spots with the VIR spectrometer? Wiki says the spectrometer can measure to 5 um. Is this enough to measure temperature? Lab thermal imagers go to 15 um or so
Post by: Apollo-phill on 06/21/2015 06:47 pm
When the Apollo lunar rock samples were analysed, Norite was a common rock type found. The attached image shows Apollo lunar rock 15455 with the large whitish material being a Norite clast. On a larger scale - with a little imagination - this image could be the Ceres dome :) :)
Norite, also known as orthopyroxene gabbro, is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine. Norite is generally found in layered igneous intrusions formed by progressive crystal fractionation. The crystallisation of large amounts of orthopyroxene can occur by the reaction of olivine with the magma. Norite is sometimes associated with anorthosite and troctolite.
Shih et al. (1993) through radiogenic aging found that the norite clast in lunar rock sample 15455 was very
old (4.59 ± 0.13 billion years). Ceres is probably as old or probably older than this ?
Whatever this dome is composed of - and I'm sure we all have our ideas and pet theories - I wanna go look myself 8) 8)
Phill Parker
Post by: Star One on 06/21/2015 07:12 pm
Post by: the_other_Doug on 06/21/2015 10:10 pm
When the Apollo lunar rock samples were analysed, Norite was a common rock type found.
Norite is common in the lunar highlands, which to be fair is something like 84% of the lunar surface. Except for small chunks of the highlands crust tossed there by impacts, norites (and the rest of the aluminous suite of plagioclase-rich highlands rocks) are rather rare in the maria, where basalts are far, far more common.
Post by: Bob Shaw on 06/21/2015 10:45 pm
The 'missing magnetometer' could have helped detect a subsurface ocean, but sadly was deleted from the mission when Dawn was re-funded. Magnetometers always seem to be the first instrument to go - they're not as sexy as cameras.
As for the amount of radioactive materials in Ceres, one must simply presume that it was in the same ball-park as the rest of the Solar System. It would therefore have been largely a radioisotope of Aluminium with a relatively short half-life which provided the bulk of the heating (rocky bodies, and rocky cores, are basically Silicon and Aluminium with an Iron core (well, Iron Sulphate)). So, geometry works against heat retention, and the half-life issue shuts down heat generation. Thus, a cold body results, unless there's tidal heating.
The real test of the gross composition is the density of the body, and that requires only some precise timing and navigation to discover. I think we'll see a not particularly differentiated, cold body, made of a rock/ice breccia.
The bright spots are, of course, something else again; the best-known appear to be linked to a classic crater, though several others have been seen. Material exposed to the Solar wind darkens, and reddens, which suggests that what we see is something that has happened recently (how unlikely is that?) or something which happens repeatedly. It may be that Ceres isn't homogenous, but is not merely rather undifferentiated but is actually quite patchy in composition, with some areas more icy than others. Our own Moon's crustal structure has been interpreted as being largely 'Mega Breccia' - perhaps Ceres is similar. By way of comparison, look at piebald Ganymede, where big chunks of ancient dark material are seen as well as lighter, more plastic areas. Similarly, in case anyone doubts whether a small icy world can support a surface superficially similar to that of our own Moon, I draw your attention to Mimas. Even on Earth we see long-lived structures like the Canadian Shield, so even bigger planets can have oddities. In summary, then, I think we're looking at frozen rocky slush, ice breccia, (we'll find out for sure from the orbital mechanics) and perhaps some volatile rich exceptions to that rule.
Post by: Bob Shaw on 06/21/2015 10:52 pm
Earlier in this forum thread ( 06/18/2015) I suggested maybe the Ceres "dome" was maybe a salt dome but I'm more inclined now to believe that it is an intrusive igneous rock - possibly Norite.
Phill:
I doubt if Ceres, if rocky, was ever warm enough to become spherical. Look at Vesta!
If not warm enough to become spherical, then nothing igneous happens either.
My money is on Ceres being similar to the ice-rich outer planet moons, but frozen solid.
Post by: Star One on 06/21/2015 11:18 pm
Earlier in this forum thread ( 06/18/2015) I suggested maybe the Ceres "dome" was maybe a salt dome but I'm more inclined now to believe that it is an intrusive igneous rock - possibly Norite.
Phill:
I doubt if Ceres, if rocky, was ever warm enough to become spherical. Look at Vesta!
If not warm enough to become spherical, then nothing igneous happens either.
My money is on Ceres being similar to the ice-rich outer planet moons, but frozen solid.
Maybe making quite so many assumptions at this stage is not the best course of action. I'd rather wait for the results and data from the actual mission that is in orbit around Ceres than pin too much money on any particular theory at this time. Many is the person in history who has come a cropper placing their money one way or another when it comes to the realities of the solar system.
Post by: rubtest on 06/21/2015 11:33 pm
from
http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Water_ice_in_crater_at_Martian_north_pole
from space however it was almost invisible.
Ceres white spot S5 shines however like a lighthouse and was observed from a distance of
more then 250k miles in the end of January 2015
I am playing with the silly notion that it might be an active light emitting source :)
I have prepared a picture with this mars ice crater superimposed on the side of S5 spot.
on the mars crater you can sense it is ice because of the ice slightly shady look.
greetings,
rubtest
Post by: meekGee on 06/21/2015 11:59 pm
We saw the spots are bright from all directions, so the light is diffuse. (or am I wrong on this?) either way, the directional light distribution is well known by now, as is the absolute amount of light coming out.
If it's putting out more light than coming in, we'd have heard about it by now. It would be the biggest bombshell in solar-system science in... in a very long time.
Even if it's just putting out more light than coming in in one particular wavelength (photoluminance) we'd have heard by now, assuming the spectrometer can resolve that crater (which judging by the wiki article, it can)
Given that there was no such announcement or leak, I take it that:
a) the spot is curiously white
b) they have lower-exposure pictures and spectrometer readings which are interesting
c) it's nothing crazy out of the ordinary. Maybe at best ice leaching out through cracks or such.
Post by: Star One on 06/22/2015 06:30 am
Well does it or does it not have an albedo > 1?
We saw the spots are bright from all directions, so the light is diffuse. (or am I wrong on this?) either way, the directional light distribution is well known by now, as is the absolute amount of light coming out.
If it's putting out more light than coming in, we'd have heard about it by now. It would be the biggest bombshell in solar-system science in... in a very long time.
Even if it's just putting out more light than coming in in one particular wavelength (photoluminance) we'd have heard by now, assuming the spectrometer can resolve that crater (which judging by the wiki article, it can)
Given that there was no such announcement or leak, I take it that:
a) the spot is curiously white
b) they have lower-exposure pictures and spectrometer readings which are interesting
c) it's nothing crazy out of the ordinary. Maybe at best ice leaching out through cracks or such.
To your question see Blackstar's cryptic comment up thread.:D
I tell you if it's giving out more light than coming in, I give up, that would just be too odd for my liking.;)
Post by: Ben the Space Brit on 06/22/2015 12:25 pm
FWIW, that side view definitely makes me think that it's some sort of deposit. The only idea I can come up with is localised cryovulcanism due to solar heating.
As a rule, Ceres's regolith is too thick for significant solar heating effects to affect the icy/ultra-salty water mantle. However, S5's host crater, which is a recent feature in geological terms, was deep enough when first formed that it penetrated deeply through the regolith; maybe it even exposed a very small part of the mantle but that isn't strictly necessary. Directly exposed to sunlight or at least receiving many times its normal level of solar UV and IR, the mantle material beneath the centre of the host crater began to boil off. The pressure generated by the vaporising material was not that great, indicating a fairly low dT. However, it was enough to create a H2O plume. Because of its low overall energy, the plume never exceeded escape velocity, so, after the H2O boiled off, the heavier salts settled back onto the surface, creating a higher-albedo area (the off-centre mark) as well as leaving a 'salt cone' around the site of the plume.
It is quite possible that the combined remainder of the depth of the regolith and the high-albedo salt cone may have stopped the boiling of mantle material. This means that S5 may now be extinct. There may be similar but very faded objects elsewhere on Ceres, reflecting a short active period followed by a relatively rapid disappearance as micrometeorite activity as well as settling of debris from other impacts creates a new layer of dark regolith, covering over the bright salts.
Post by: rubtest on 06/22/2015 02:33 pm
credit: http://meetings.copernicus.org/www.cosis.net/abstracts/EGU05/10256/EGU05-J-10256.pdf
the brightest large area that we observe on earth that stays bright also in obliqued view is..... FRESH snow. not ice , not old snow. and it can also piled to a high mounds , ask the people in the Boston area :)
fresh snow albedo: 0.8 -0.9
so the scenario that was described in previous posting in this thread can really explain S5 spots
active thermal heating of underground water reservoir
-> rock fissures, maybe triggered by new meteorite impact
-> escaping vapors freezing
-> pressure from reservoir keeps vapor escaping the fissures and creates snow mounds which slowly sublimate into the
airless atmosphere.
natural made snow machine :)
greetings
rubtest
Post by: Star One on 06/22/2015 02:57 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19579
http://photojournal.jpl.nasa.gov/catalog/PIA19578
http://photojournal.jpl.nasa.gov/catalog/PIA19577
Post by: meekGee on 06/22/2015 04:23 pm
looking at HST albedo measurements of Ceres, it shows an average albedo of 0.09 , like an earth forest from above.
credit: http://meetings.copernicus.org/www.cosis.net/abstracts/EGU05/10256/EGU05-J-10256.pdf
the brightest large area that we observe on earth that stays bright also in obliqued view is..... FRESH snow. not ice , not old snow. and it can also piled to a high mounds , ask the people in the Boston area :)
fresh snow albedo: 0.8 -0.9
so the scenario that was described in previous posting in this thread can really explain S5 spots
active thermal heating of underground water reservoir
-> rock fissures, maybe triggered by new meteorite impact
-> escaping vapors freezing
-> pressure from reservoir keeps vapor escaping the fissures and creates snow mounds which slowly sublimate into the
airless atmosphere.
natural made snow machine :)
greetings
rubtest
How will snow evolve under vacuum?
The high Albedo will slow down heat absorption and reduce the temperature, but the large surface area will accelerate sublimation - a race condition...
A cold surface temperature might additionally act as a cryo trap - I wonder again if there's any way to measure the temperature of the white spot. The instruments don't seem to be set up for that.
Post by: notsorandom on 06/22/2015 05:33 pm
Post by: meekGee on 06/22/2015 06:03 pm
Surface temperature of Ceres is 130-200 Kelvin. Significantly warmer than the cold traps on the Moon and Mercury. S5 is also pretty near the equator and receives a good deal of sunlight. Sublimation may be quite significant. The Bright spot has been seen since the first time Hubble looked at Ceres ten years ago. If it is ice then conditions either have to allow for it to exist without sublimating away for ten+ years or the ice be constantly refreshed.
That's average surface temperature. If the Albedo is not uniform, the temperatures won't be either. It's a big difference if you're reflecting 90% or 70% of the incoming light - it's a x3 difference in the heat load.
The snow may also benefit from "Dewer mechanism" - in that whatever sublimation there is helps keep the rest of the snow cold.
Post by: Star One on 06/22/2015 06:48 pm
Post by: notsorandom on 06/22/2015 07:07 pm
Even a little sublimation over time would force some pretty interesting conclusions. It is likely that the geology of Ceres aside from impacts has been set for the last few billion years. Even a little bit of sublimation over such timescales would mean that the ice would have disappeared by now. It couldn't have been left over since when we think Ceres was geologically active because it was so long ago. If what we are seeing now is ice and if sublimation is even a small factor that means one of two things. The ice has been deposited recently geologically speaking or that it has recently been uncovered. Salts and other minerals can exist for longer times than water ice meaning if Ceres is a dead world they are more likely the culprit. Especially since water can carry salts and other dissolved minerals.Surface temperature of Ceres is 130-200 Kelvin. Significantly warmer than the cold traps on the Moon and Mercury. S5 is also pretty near the equator and receives a good deal of sunlight. Sublimation may be quite significant. The Bright spot has been seen since the first time Hubble looked at Ceres ten years ago. If it is ice then conditions either have to allow for it to exist without sublimating away for ten+ years or the ice be constantly refreshed.
That's average surface temperature. If the Albedo is not uniform, the temperatures won't be either. It's a big difference if you're reflecting 90% or 70% of the incoming light - it's a x3 difference in the heat load.
The snow may also benefit from "Dewer mechanism" - in that whatever sublimation there is helps keep the rest of the snow cold.
Post by: Star One on 06/22/2015 07:38 pm
Post by: RotoSequence on 06/22/2015 08:44 pm
What none of this answers is the possible discovery of Ceres giving off water vapour, if Ceres was truly dead geologically it wouldn't be giving off water vapour if this is what is occurring.
Shouldn't we have seen some signs of active hydrology by now if that were the cause?
Post by: hop on 06/22/2015 09:28 pm
Shouldn't we have seen some signs of active hydrology by now if that were the cause?Who says we haven't? There are multiple distinct, unexplained features which could be associated with water release.
Assuming it was real, Herschel detection was quite small, so large scale surface activity is not expected or required.
http://www.esa.int/Our_Activities/Space_Science/Herschel/Herschel_discovers_water_vapour_around_dwarf_planet_Ceres
Quote
“We estimate that approximately 6 kg of water vapour is being produced per second, requiring only a tiny fraction of Ceres to be covered by water ice, which links nicely to the two localised surface features we have observed,”
Post by: John-H on 06/22/2015 10:16 pm
Could Ceres be a comet?
John
Post by: Star One on 06/22/2015 11:22 pm
What none of this answers is the possible discovery of Ceres giving off water vapour, if Ceres was truly dead geologically it wouldn't be giving off water vapour if this is what is occurring.
Shouldn't we have seen some signs of active hydrology by now if that were the cause?
What about this still unexplained fuzziness in the images around the bright spots, though not discountable as due to resolution issues, it is a persistent feature. Could it be fine spray of particles.
@John-H I've often speculated as too what you would find if you could remove that layer of dust from Ceres, what would be revealed.
Post by: RotoSequence on 06/23/2015 04:16 am
What none of this answers is the possible discovery of Ceres giving off water vapour, if Ceres was truly dead geologically it wouldn't be giving off water vapour if this is what is occurring.
Shouldn't we have seen some signs of active hydrology by now if that were the cause?
What about this still unexplained fuzziness in the images around the bright spots, though not discountable as due to resolution issues, it is a persistent feature. Could it be fine spray of particles.
I dunno... to me, it doesn't sound like a very good fit for what we've seen of the bright spots edge-on.
Post by: Ben the Space Brit on 06/23/2015 11:25 am
Post by: Star One on 06/23/2015 04:52 pm
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19580
Post by: nadreck on 06/23/2015 05:08 pm
Here's the image for today.
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19580
Ok the central crater in this photo and the one in http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19575 (http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19575) to me both have elements that I don't think belong in an impact crater, and remind me of this:
http://www.geo-airbusds.com/cn/5777-image-detail?img=24132#.VYmPeflVhBc (http://www.geo-airbusds.com/cn/5777-image-detail?img=24132#.VYmPeflVhBc) which is a caldera subsidence crater. Some elements of both of the Ceres ones above suggest several subsidence events. If one postulates a Ceres subsurface from 100m to 100,000m or more deep that is a very gravelly snowball (so like a glacier), that material can flow from impact and potentially act much like much warmer magma on earth deeper down (5 to 10km typically, but around caldera's obviously much less) and cause an effect analagous to earth bound calderas.
Post by: rubtest on 06/24/2015 09:29 am
Is it not the right time to open a party thread for the white S5 spot ?
I sense some creativity lies dormant here.
Cheers
Post by: TakeOff on 06/24/2015 04:01 pm
Yeah, that's the rub. Pyramids are simple geometrical shapes which maybe can occur spontaneously from natural events like asteroid impacts or volcanism or tidal forces or chrystalization or something. Egyptologists now certainly investigate the potential of these explanations for the existence of pyramids in Giza, Egypt. The Sphinx, formed as a female face on the body of a lion with an eagle's wings, is a bit harder to explain that way. But one single outlier was never a problem for astronomy anyway. :-DBetter images of the pyramid.:)
Now looking for the Sphinx?
Post by: Star One on 06/24/2015 04:13 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19581
Post by: meekGee on 06/24/2015 07:23 pm
Yeah, that's the rub. Pyramids are simple geometrical shapes which maybe can occur spontaneously from natural events like asteroid impacts or volcanism or tidal forces or chrystalization or something. Egyptologists now certainly investigate the potential of these explanations for the existence of pyramids in Giza, Egypt. The Sphinx, formed as a female face on the body of a lion with an eagle's wings, is a bit harder to explain that way. But one single outlier was never a problem for astronomy anyway. :-DBetter images of the pyramid.:)
Now looking for the Sphinx?
I'd be interested in the mechanism that formed THAT pyramid without requiring the invention of slave labor...
EDIT:
To clarify, I was talking about the pyramid image in the post I quoted, not the Ceres "pyramid-like" mountain, which is clearly too large to have been built by slaves, unless they were very large ones.
Post by: Star One on 06/24/2015 08:30 pm
Yeah, that's the rub. Pyramids are simple geometrical shapes which maybe can occur spontaneously from natural events like asteroid impacts or volcanism or tidal forces or chrystalization or something. Egyptologists now certainly investigate the potential of these explanations for the existence of pyramids in Giza, Egypt. The Sphinx, formed as a female face on the body of a lion with an eagle's wings, is a bit harder to explain that way. But one single outlier was never a problem for astronomy anyway. :-DBetter images of the pyramid.:)
Now looking for the Sphinx?
I'd be interested in the mechanism that formed THAT pyramid without requiring the invention of slave labor...
EDIT:
To clarify, I was talking about the pyramid image in the post I quoted, not the Ceres "pyramid-like" mountain, which is clearly too large to have been built by slaves, unless they were very large ones.
Well the Egyptians did OK with pyramid building.
Post by: Bob Shaw on 06/24/2015 09:14 pm
Why would Ceres have scarps? Because when the water which composes (say) 40% of it by mass (arm-waving apologies in advance) froze several billion YA ago at the end of the LH, it behaved the way water ice does. Water ice *expands*. Add gardening by impacts, and the odd post-impact water-ice 'lava' episode or ten - we might yet see some localised cryoclastic flow events too - not 'rivers' as we normally think of them, but violent episodes with fluidised debris chewing gouges out of areas 'downriver' of impacts. If other volatiles were present in patches we might see different patterns of erosion in some areas where there were patchy volatile deposits.
Here's my tests for an expanded crust: hexagonal craters over 100miles across; a 'grid pattern'; scarps breaking up craters; pit chains.
And for post-impact water vulcanism: some *very* flat crater floors, broken by scarps, with pit chains.
There would normally be no 'traditional' river systems, but there remains the possibility of local post-impact water flows as possibly seen on Vesta.
Post by: Star One on 06/25/2015 04:02 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19582
Post by: kevin-rf on 06/25/2015 07:21 pm
Yeah, that's the rub. Pyramids are simple geometrical shapes which maybe can occur spontaneously from natural events like asteroid impacts or volcanism or tidal forces or chrystalization or something. Egyptologists now certainly investigate the potential of these explanations for the existence of pyramids in Giza, Egypt. The Sphinx, formed as a female face on the body of a lion with an eagle's wings, is a bit harder to explain that way. But one single outlier was never a problem for astronomy anyway. :-D
Actually I've seen some theories that the basic sphinx form came from wind erosion, and face and fine details where carved in at a later date. Actually one claim is the current face is the second face to be carved into it.
So all Ceres needed was an atmosphere and wind storms or a thousand slaves in spacesuits ;)
Post by: NovaSilisko on 06/25/2015 07:43 pm
Here's today's image which overlaps with yesterday's one.
http://photojournal.jpl.nasa.gov/catalog/PIA19582
I aligned it with the previous image, based on the bright spot and nearby crater. The light angles differ, and I adjusted the brightness a little to make it blend better. The perspective is a bit off, though.
Post by: leovinus on 06/25/2015 07:53 pm
* How prevalent are salt deposit on other planetary bodies?
* How prevalent are visible ice deposits in the solar system? We have seen them on Mars, and likely, recent speckles on comet Churyumov-Gerasimenko. Anything else?
* Do we know of other visible, high-albedo deposits in the solar system, which are neither salt nor ice?
* How does that knowledge help in interpreting Ceres bright spots? Is Ceres like a very big comet in a stable orbit?
* Are any original non-JPEG, non-PNG, probably FITS formatted photo's of the bright spots available for the public? Would help in further discussion and analysis.
Post by: hop on 06/25/2015 08:20 pm
* Are any original non-JPEG, non-PNG, probably FITS formatted photo's of the bright spots available for the public?No. Ceres science data hasn't hit PDS. It will in due course.
http://sbn.psi.edu/pds/archive/dawn.html
Quote
Ceres data - to be delivered for archiving in 2015 and 2016.
IMO, VIR is far more likely to provide a definitive answer. The dawn team will undoubtedly publish papers about the spots before the data is released on PDS. They may or may not have a press briefing before the papers come out.
Post by: Star One on 06/26/2015 04:02 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19583
Looks like a contrast I've noted before of what appears like ancient untouched surface and areas that look like they've been resurfaced at some point.
Global map.
http://laps.noaa.gov/albers/sos/asteroids/ceres_rgb_cyl.png
From here.
http://laps.noaa.gov/albers/sos/sos.html#Ceres
Post by: Ben the Space Brit on 06/27/2015 05:28 pm
Post by: Star One on 06/29/2015 05:18 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19584
Post by: NovaSilisko on 06/29/2015 05:20 pm
Post by: Star One on 06/29/2015 07:14 pm
Quote
“We should get the answer when we pass over the bright spot again,” Russell wrote in his email. “We do see the contour of the ground, and it seems that it is not a hill but possibly a dip in the surface that is bright, but we need to complete the survey orbits in order to accurately obtain the topography of the area.”
“We do not know yet what make this peak on Ceres, let alone made it the observed shape,” Russell said. “This is another total surprise to the team. However, there are processes on Earth that can grow mounds out of ground water in Arctic terrains on Earth. But these are much smaller structures.
“We see only one of these on Ceres... Its uniqueness makes our understanding more difficult,” he added.
http://www.latimes.com/science/sciencenow/la-sci-sn-ceres-pyramid-bright-spots-dawn-nasa-dwarf-planet-20150626-story.html
Post by: meekGee on 06/29/2015 07:21 pm
Today's image & finally the spots are no longer over exposed. But unfortunately you still can't tell what they are. The image does at least show you how dark the rest of Ceres is in comparison to the spots.
http://photojournal.jpl.nasa.gov/catalog/PIA19584
They're messing with us on purpose.
Post by: notsorandom on 06/29/2015 07:24 pm
Post by: Star One on 06/29/2015 08:06 pm
Also that the mountain looks like a giant Pingo, far bigger than the ones on Earth. (I always spell that wrong at first & put Pingu, which would imply Ceres had a 5 Kilometre high penguin on its surface.)
Post by: Star One on 06/30/2015 05:01 pm
Quote
Listening to Carol Raymond tell Dawn results at Ceres. The "pyramid" or cone has bright streaks running down its side. No explanation. Cool!
https://mobile.twitter.com/DrPhiltill/status/615908430872711168
Here's today's Ceres image from Dawn.
http://photojournal.jpl.nasa.gov/catalog/PIA19585
New blogpost from the Planetary Society.
http://www.planetary.org/blogs/guest-blogs/marc-rayman/0630-dawn-journal-ceres-intriguing-geology.html
Post by: meekGee on 07/01/2015 04:37 am
Ceres itself is nothing more than an accumulation of outflow coming out of the tip of this Ceres Progenitor Nozzle.
Post by: Star One on 07/01/2015 05:00 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19586
Post by: Star One on 07/02/2015 05:28 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19587
Post by: Ben the Space Brit on 07/03/2015 11:17 am
I'm sticking with my belief that the large bright spots in the S5 crater are the result of very recent and distinct event from the cause of the wider-scale cryovulcanism.
Post by: IRobot on 07/03/2015 11:33 am
It's the mountain again this time from the side.When I see that image I can only think of a Kerbal spacecraft closing on Mün.
http://photojournal.jpl.nasa.gov/catalog/PIA19587
Post by: Zed_Noir on 07/03/2015 10:02 pm
It's the mountain again this time from the side.
http://photojournal.jpl.nasa.gov/catalog/PIA19587
Is there any unofficial name for the mountain from JPL?
Someone jokingly call it Erebor on the web. :)
Post by: Star One on 07/06/2015 04:31 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19588
Some pretty serve impact craters on there.
Post by: Ben the Space Brit on 07/06/2015 08:30 pm
Post by: Star One on 07/07/2015 05:01 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19589
Dawn Holding in Second Mapping Orbit
DAWN MISSION STATUS REPORT
NASA's Dawn spacecraft is healthy and stable, after experiencing an anomaly in the system that controls its orientation. It is still in its second mapping orbit 2,700 miles (4,400 kilometers) above dwarf planet Ceres.
On June 30, shortly after turning on its ion engine to begin the gradual spiral down to the next mapping orbit, its protective software detected the anomaly. Dawn responded as designed by stopping all activities (including thrusting), reconfiguring its systems to safe mode and transmitting a radio signal to request further instructions. On July 1 and 2, engineers made configuration changes needed to return the spacecraft to its normal operating mode. The spacecraft is out of safe mode, using the main antenna to communicate with Earth.
Dawn will remain at its current orbital altitude until the operations team has completed an analysis of what occurred and has updated the flight plan.
Because of the versatility of Dawn's ion propulsion system and the flexibility of the mission's plan for exploring Ceres, there is no special "window" for starting or completing the spiral to the third mapping orbit. The plans for the third and fourth mapping orbits can be shifted to new dates without significant changes in objectives or productivity.
More information on the Dawn mission is online at:
http://www.nasa.gov/dawn
http://dawn.jpl.nasa.gov
Elizabeth Landau
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
[email protected]
2015-229
Last Updated: July 7, 2015
Editor: Tony Greicius
http://www.nasa.gov/jpl/dawn-holding-in-second-mapping-orbit
Post by: yg1968 on 07/14/2015 03:29 pm
Post by: Ben the Space Brit on 07/15/2015 07:16 am
As I understand it, 'true colour' on Ceres is a set of shades of grey varying between charcoal and all-out black with the occasional shiny spot. Look at pictures of Callisto (a larger object from a similar part of the solar system) and you'll get the idea.
Post by: Star One on 07/15/2015 10:16 am
Post by: RotoSequence on 07/15/2015 10:23 am
How much longer is Dawn going to remain in the survey orbit, have the issues not been resolved yet?
Dawn remains in its survey orbit, and the issue's cause remains unresolved as of the 13th.
http://dawn.jpl.nasa.gov/mission/status.html
Post by: Star One on 07/15/2015 03:09 pm
How much longer is Dawn going to remain in the survey orbit, have the issues not been resolved yet?
Dawn remains in its survey orbit, and the issue's cause remains unresolved as of the 13th.
http://dawn.jpl.nasa.gov/mission/status.html
Thanks. Really hope it's not stuck in that orbit for good.
Post by: dwheeler on 07/17/2015 09:57 pm
Dawn Maneuvering to Third Science Orbit
Mission Status Report
NASA's Dawn spacecraft is using its ion propulsion system to descend to its third mapping orbit at Ceres, and all systems are operating well. The spiral maneuvering over the next five weeks will take the spacecraft to an altitude of about 900 miles (less than 1,500 kilometers) above the dwarf planet.
The spacecraft experienced a discrepancy in its expected orientation on June 30, triggering a safe mode. Engineers traced this anomaly to the mechanical gimbal system that swivels ion engine #3 to help control the spacecraft's orientation during ion-thrusting. Dawn has three ion engines and uses only one at a time.
Dawn's engineering team switched to ion engine #2, which is mounted on a different gimbal, and conducted tests with it from July 14 to 16. They have confirmed that the spacecraft is ready to continue with the exploration of Ceres.
By the end of the day on July 17, Dawn will have descended to an altitude of about 2,400 miles (3,900 kilometers). After arrival at its next mapping orbit -- called the High-Altitude Mapping Orbit, or HAMO -- in August, Dawn will begin taking images and other data at unprecedented resolution.
More information on the Dawn mission is online at:
http://www.nasa.gov/dawn (http://www.nasa.gov/dawn)
http://dawn.jpl.nasa.gov (http://dawn.jpl.nasa.gov)
Post by: Star One on 07/17/2015 11:46 pm
Post by: Nomadd on 07/18/2015 01:32 am
Does that mean they can now longer use that engine for any manoeuvres?Can't really say without knowing the nature of the gimbal problem. If it can't move and isn't aimed right through the center of mass, it wouldn't be much good.
Post by: cleonard on 07/18/2015 01:45 am
Dawn only has a few percent of the Xenon fuel remaining. Loosing use of one of three of the engines likely is not much of an issue at this point.Does that mean they can now longer use that engine for any manoeuvres?Can't really say without knowing the nature of the gimbal problem. If it can't move and isn't aimed right through the center of mass, it wouldn't be much good.
Post by: the_other_Doug on 07/18/2015 02:36 am
Post by: dwheeler on 07/18/2015 04:35 am
...Then, it will spiral down to an altitude of about 2,750
miles (4,430 kilometers), and obtain more science
data in its survey science orbit. This phase will last for
22 days and is designed to obtain an improved global
view of Ceres with the camera and the visible and
infrared mapping spectrometer (VIR).
Dawn will then continue to spiral down to an altitude
of about 920 miles...
So I assume they've completed the 2750 mile high survey successfully, including good spectrometer (VIR) readings. For the VIR instrument, the presskit said:
The surface mineralogy of both Vesta and Ceres
is measured by the visible and infrared mapping
spectrometer, or VIR. <snip> Each picture
the instrument takes records the light intensity at
more than 400 wavelength ranges in every pixel.
When scientists compare its observations with
laboratory measurements of minerals, they can
determine what minerals are on the surfaces of
Vesta and Ceres.
So will/did that instrument give them the chemical composition of the bright spots, or do we need to wait for the gamma ray and neutron detector (GRaND) instrument 4 (bleaping) months from now? (Unless they're big piles of diamonds or ancient alien colony artifacts I'll be disappointed... I just want to get it out of the way already... :D)
Post by: nadreck on 07/18/2015 07:15 pm
It's not like Dawn is going anywhere after this. It will be put into a "storage" orbit around Ceres when the mission is over. It doesn't need all of the ion engines any more, it can do all the planned maneuvers with just one.
It never needed all of them they were for redundancy and it only used one at a time. That redundancy has paid off to get it to the point of finishing the mission given the one engine failing around Vesta.
Post by: vjkane on 07/18/2015 09:02 pm
So will/did that instrument give them the chemical composition of the bright spots, or do we need to wait for the gamma ray and neutron detector (GRaND) instrument 4 (bleaping) months from now? (Unless they're big piles of diamonds or ancient alien colony artifacts I'll be disappointed... I just want to get it out of the way already... :D)It may be that the pixel size of the near IR spectrometer is to large to get a clean signal on the white material (the pixel sees both white and normal surface material). Lower orbits will bring smaller pixel sizes.
Post by: Star One on 07/18/2015 09:36 pm
It's not like Dawn is going anywhere after this. It will be put into a "storage" orbit around Ceres when the mission is over. It doesn't need all of the ion engines any more, it can do all the planned maneuvers with just one.
It never needed all of them they were for redundancy and it only used one at a time. That redundancy has paid off to get it to the point of finishing the mission given the one engine failing around Vesta.
Did that one fail for a similar reason?
Post by: nadreck on 07/19/2015 03:38 am
No it was the electrical controler: https://en.wikipedia.org/wiki/Dawn_(spacecraft)#Transit_.28Vesta_to_Ceres.29 (https://en.wikipedia.org/wiki/Dawn_(spacecraft)#Transit_.28Vesta_to_Ceres.29)It's not like Dawn is going anywhere after this. It will be put into a "storage" orbit around Ceres when the mission is over. It doesn't need all of the ion engines any more, it can do all the planned maneuvers with just one.
It never needed all of them they were for redundancy and it only used one at a time. That redundancy has paid off to get it to the point of finishing the mission given the one engine failing around Vesta.
Did that one fail for a similar reason?
Post by: Bubbinski on 07/21/2015 07:38 pm
Let's get a lander/rover out there.
Post by: ugordan on 07/21/2015 07:52 pm
Post by: notsorandom on 07/21/2015 07:58 pm
Post by: Bubbinski on 07/21/2015 09:27 pm
http://www.nature.com/news/mystery-haze-appears-above-ceres-bright-spots-1.18032
Post by: Ben the Space Brit on 07/21/2015 09:30 pm
Followed by a sudden headache. How the heck does an object the size of Ceres, so far from any large primaries, get to be active? I can imagine the TNOs having some kind of geological voodoo that lets it happen but Ceres is a totally different case... Isn't it?
Post by: Star One on 07/21/2015 09:53 pm
In relation to this an interesting quote from that Nature article.
Quote
Ceres' striking 5-kilometre-high mountain, informally dubbed ”the pyramid”, may be similar to the mountains seen last week on Pluto by the New Horizons spacecraft, Russell adds.
Post by: leovinus on 07/22/2015 02:21 pm
The tweets are apparently coverage of a talk being given by Dawn PI Chris Russell at NASA Exploration Science Forum 2015. Any other confirmation that is what was said?
This was the 11:40am talk. The program is at
http://nesf2015.arc.nasa.gov/agenda
which now has a link to the full talk.
Post by: the_other_Doug on 07/22/2015 04:18 pm
Is it because someone wants to publish a paper about it, so they won't release any of the "proof" until the paper is published?
If that is the case, then I would highly recommend that those who want to publish keep their friggin' traps shut about their "discoveries" until they are actually ready to publish. Otherwise, they reduce the entire science team to trolling the planetary science community, trumpeting alleged discoveries but unwilling to provide a shred of evidence to back up their strutting and preening.
We went through something like this over at umsf nearly a decade ago, when the raw images from Cassini showed plumes coming from Enceladus. Members of the Cassini imaging team who happened to post on that forum actually lied outright, saying no one on the science team saw anything of importance, right up to the time they announced their findings. And to support their actions, Carolyn Porco made an infamous post on that forum stating (and I'm paraphrasing here) that Cassini was "our picnic, we put in the time and effort, so we should get the benefit of keeping the data to ourselves and looking at it first." When hit with an overwhelming response that it was NOT their picnic, but was a picnic paid for by the American public via our tax dollars, she shut up awfully quickly. And the policy of immediate release of raw Cassini images wasn't changed.
Methinks someone on the Dawn team either needs to keep that lesson in mind, or needs to just release the images showing these haze layers. You either act like ESA and ignore all public release dates, letting your PIs act like data hoarders (I imagine them sitting in darkened rooms, looking at amazing pictures, and chuckling "NO ONE ELSE KNOWS what I know! NO ONE ELSE can see what I see! I AM SO SPECIAL!!! HAHAHAHAHA!!!!!"), or you follow the NASA/JPL/APL model and release all your image data, in non-calibrated raw jpgs (unsuitable for full scientific analysis, but suitable to give the public an idea of what the science team is seeing) as you acquire them.
But you don't chortle about amazing new discoveries via Twitter and then utterly fail to produce any of the images upon which your chortlings are based. At least, IMHO.
Post by: ugordan on 07/22/2015 04:23 pm
We went through something like this over at umsf nearly a decade ago, when the raw images from Cassini showed plumes coming from Enceladus. Members of the Cassini imaging team who happened to post on that forum actually lied outright, saying no one on the science team saw anything of importance, right up to the time they announced their findings.
Heh. Am I misremembering it or did someone actually claim the backlit plumes were scattered light in the optics? ::)
Post by: the_other_Doug on 07/22/2015 04:49 pm
We went through something like this over at umsf nearly a decade ago, when the raw images from Cassini showed plumes coming from Enceladus. Members of the Cassini imaging team who happened to post on that forum actually lied outright, saying no one on the science team saw anything of importance, right up to the time they announced their findings.
Heh. Am I misremembering it or did someone actually claim the backlit plumes were scattered light in the optics? ::)
Exactly. And more I shall not say, since I have the decided impression that saying anything further here, even though it is not a post to the Planetary Society-supported umsf forum, could still get me reprimanded, or even banned, from that site.
I do understand that you don't want such a science-oriented forum, with high signal-to-noise, to get inundated by people questioning the science teams. But there are some questions that ought to be allowed anywhere, and one of them must be "Oh, yeah? Let's see your evidence."
In my mind, extraordinary claims require extraordinary evidence. You just don't go making such claims and then fail to come across with the images that have led you to make them. I'm hopeful this is just a glitch in the release process and we'll be seeing them soon. But until then, I will continue to ask, "Oh, yeah? Let's see your evidence."
Post by: zubenelgenubi on 07/22/2015 05:13 pm
But you don't chortle about amazing new discoveries via Twitter and then utterly fail to produce any of the images upon which your chortlings are based. At least, IMHO.If the Dawn team wasn't ready to release their findings, then Chris Russell shouldn't have been presenting to an "open" audience. Especially in 2015, when Tweets can be broadcast from the auditorium--no longer is there the dash to the payphones outside the room to call in the hot news!
Thank you for your thoughtful and knowledgeable posts on this and the UMSF fora.
Zubenelgenubi
Post by: Star One on 07/22/2015 05:42 pm
Post by: sghill on 07/22/2015 05:44 pm
The sun angle (sun at the bottom of the image, shadows stretching towards the top) is correct for casting these shadows if a faint plume is indeed in the process of being released.
Obviously, these are noisy compressed images taken thousands of miles away of an alien world, but since we're on the topic, I thought I'd contribute my observation to the discussion.
Post by: ugordan on 07/22/2015 05:52 pm
Well since we are talking now about active cryro features and "haze", IN MY OPINION, the shadowing towards the top of the attached photo looks exactly like the kinds of shadows you's see cast by smoke plumes.
I'll have to disagree on that. If a plume made that kind of a shadow, it would mean it's scattering away a noticeable amount of sunlight. So why don't we see the plume directly, then?
If the plume is very faint (think Enceladus' south pole vents), then it doesn't cast shadows and is barely visible itself in forward-scattered light.
There's also the fact that the haze is apparently confined within the crater rim.
Finally, I believe that's an unchanging terrain feature, which again wouldn't corrobate the periodic plume theory.
Post by: the_other_Doug on 07/22/2015 06:22 pm
With what is being reported at present, ugordan is right that a simple light haze, only seen from forward-scattering of sunlight, contained within the crater wall, would not produce such discoloration outside of the crater. But what if the bright features began as more energetic geysers, which did spray material outside of the crater? And whatever material was emplaced by such geysers has since darkened in the sunlight, leaving the darkened terrain we see there now?
You'd have to do some deeper investigation of the composition of the bright features, as well as of the darkened terrain, to see if there is any truthiness to this conjecture. And you'd need some photochemical reasoning as to why any material emplaced from a bright feature would darken. But I wouldn't completely rule out that the darkened areas might have been caused by activity from the Occator bright features -- just, perhaps, that it happened a while ago, not in the past few days/weeks/months/years. Or maybe the first gasses shot out of said geysers were entrained with dark dust, and that was emplaced around the region, and was then followed by the bright-entrained material coming from farther within Ceres?
Again, only higher-resolution imaging and better compositional analyses will tell us much to determine the facts one way or another. But I'm looking forward to getting the data -- and having the data shared.
Post by: ugordan on 07/22/2015 06:36 pm
But what if the bright features began as more energetic geysers, which did spray material outside of the crater? And whatever material was emplaced by such geysers has since darkened in the sunlight, leaving the darkened terrain we see there now?
This is a more plausible idea, I think. I never implied the darkened area had nothing to do with Occator's spots, I was making an argument that it couldn't realistically be an active plume shadow.
Post by: Bubbinski on 07/22/2015 06:50 pm
Another article about this: http://www.planetary.org/blogs/guest-blogs/2015/0721-dawn-at-ceres-a-haze-in-occator-rivkin.html
Post by: Star One on 07/22/2015 06:59 pm
Post by: clongton on 07/22/2015 11:54 pm
Post by: Star One on 07/28/2015 05:59 pm
http://www.nasa.gov/jpl/dawn/new-names-and-insights-at-ceres
Post by: clongton on 07/29/2015 01:54 am
New topographic and themal maps of Ceres
http://www.nasa.gov/jpl/dawn/new-names-and-insights-at-ceres
That is extremely well done!
Post by: catdlr on 08/06/2015 03:32 pm
Published on Aug 6, 2015
Take a tour of weird Ceres! Visit a 2-mile-deep crater and a 4-mile-tall mountain in the video narrated by mission director Marc Rayman. Get your red/blue glasses ready for the finale - a global view of the dwarf planet in 3D.
https://youtu.be/Inc9BtRip04
Post by: Star One on 08/06/2015 07:13 pm
Quote
That third observing campaign will begin on August 17 and last more than two months.
http://dawnblog.jpl.nasa.gov/2015/07/29/dawn-journal-july-29/
Post by: yg1968 on 08/15/2015 04:44 am
Quote
August 13, 2015 - Dawn Arrives in Third Mapping Orbit
Dawn completed the maneuvering to reach its third mapping orbit and stopped ion-thrusting this afternoon. This was a little ahead of schedule because the spiral descent went so well that some of the allocated thrusting time was not needed. Since July 14, the spacecraft has reduced its orbital altitude from 2,700 miles (4,400 kilometers) to approximately 915 miles (1,470 kilometers). The orbit period has correspondingly decreased from 3.1 days to 19 hours.
Dawn is scheduled to begin its new observations on the evening of Aug. 17 (PDT) and continue for more than two months. First, however, the mission control team will measure the actual orbit parameters accurately and transmit them to the spacecraft.
http://dawn.jpl.nasa.gov/mission/status.html
Post by: redliox on 08/15/2015 06:33 am
Post by: RotoSequence on 08/15/2015 08:54 am
Hopefully the remainder of Dawn's mission at Ceres goes smoothly. At least unlike New Horizons, Dawn will be able to bring in substantially more long-term data. I'm curious what the resolution at this orbit will be and then again at the final one; given the last orbit was almost 4 times wider than this new one it's obvious we'll see even more details of this mother-of-asteroids.
http://dawnblog.jpl.nasa.gov/2015/07/29/dawn-journal-july-29/
140 meters per pixel at the new orbit (HAMO), 35 meters per pixel in Dawn's final orbit (LAMO).
Post by: Nomadd on 08/15/2015 12:12 pm
Post by: yg1968 on 08/21/2015 03:21 am
Quote
August 17, 2015 - Third Mapping Campaign to Begin Tonight
The mission control team has now provided Dawn with accurate knowledge of its orbit parameters. They have also completed transmitting all of the other information it needs and confirmed that the explorer is ready for its new Ceres mapping campaign.
Dawn has been pointing its main antenna to Earth since Aug. 13. Shortly after 9:00 pm PDT today it will start rotating to point its camera and other sensors at the landscape below and will begin taking pictures over the north pole less than an hour later.
http://dawn.jpl.nasa.gov/mission/status.html
Post by: Scylla on 08/25/2015 05:24 pm
The closest-yet views of Ceres, delivered by NASA's Dawn spacecraft, show the small world's features in unprecedented detail, including Ceres' tall, conical mountain; crater formation features and narrow, braided fractures.
"Dawn is performing flawlessly in this new orbit as it conducts its ambitious exploration. The spacecraft's view is now three times as sharp as in its previous mapping orbit, revealing exciting new details of this intriguing dwarf planet," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory, Pasadena, California.
At its current orbital altitude of 915 miles (1,470 kilometers), Dawn takes 11 days to capture and return images of Ceres' whole surface. Each 11-day cycle consists of 14 orbits. Over the next two months, the spacecraft will map the entirety of Ceres six times.
The spacecraft is using its framing camera to extensively map the surface, enabling 3-D modeling. Every image from this orbit has a resolution of 450 feet (140 meters) per pixel, and covers less than 1 percent of the surface of Ceres.
At the same time, Dawn's visible and infrared mapping spectrometer is collecting data that will give scientists a better understanding of the minerals found on Ceres' surface.
Engineers and scientists will also refine their measurements of Ceres' gravity field, which will help mission planners in designing Dawn's next orbit -- its lowest -- as well as the journey to get there. In late October, Dawn will begin spiraling toward this final orbit, which will be at an altitude of 230 miles (375 kilometers).
Dawn is the first mission to visit a dwarf planet, and the first to orbit two distinct solar system targets. It orbited protoplanet Vesta for 14 months in 2011 and 2012, and arrived at Ceres on March 6, 2015.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
http://www.nasa.gov/jpl/dawn-sends-sharper-scenes-from-ceres
Image 1- The Lonely Mountain
http://www.nasa.gov/jpl/pia19631/the-lonely-mountain
Image 2- Urvara Peaks
http://www.nasa.gov/jpl/pia19632/urvara-peaks
Image 3- Gaue Crater
http://www.nasa.gov/jpl/pia19633/gaue-crater-ceres
Image Credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Post by: Star One on 08/25/2015 07:34 pm
That mountain looks to have vents on at least three of its sides.
Post by: Scylla on 08/25/2015 08:06 pm
No Occator images so far then.
That mountain looks to have vents on at least three of its sides.
Shiny too. Cryovolcano?🗻
Post by: llanitedave on 08/25/2015 08:14 pm
No Occator images so far then.
That mountain looks to have vents on at least three of its sides.
Shiny too. Cryovolcano?🗻
I'm not so sure. There's no flow pattern surrounding it, nor on the sides. The radial lines on the slope are almost perfectly straight, as if they're slickensides along a fault surface. I wonder if the whole mountain hasn't been pushed up bodily as a single event.
Post by: rubtest on 08/25/2015 09:49 pm
and it sits on a floor as if it does not belong there ( all around is covered with mini and micro craters except the hill slopes )
maybe it is the 6 km ice slab that was in the crater and was catapulted aside and flipped over without breaking via unclear catastrophic event .
( if it is ice the hill is very heavy . around 500 cubic kilometer volume . Ice slab actually can never hold such stresses )
but in low gravity ?
Post by: meekGee on 08/25/2015 10:45 pm
speculation : the mountain has a footprint similar in size to the crater below.
and it sits on a floor as if it does not belong there ( all around is covered with mini and micro craters except the hill slopes )
maybe it is the 6 km ice slab that was in the crater and was catapulted aside and flipped over without breaking via unclear catastrophic event .
( if it is ice the hill is very heavy . around 500 cubic kilometer volume . Ice slab actually can never hold such stresses )
but in low gravity ?
That's a new idea, I'll give you that. :) Flipped and rotated 90 degrees.
What will be the velocity on impact if it fell from its own height (6 km was it?) under Ceres gravity?
Post by: cosmicvoid on 08/26/2015 06:27 am
Post by: zubenelgenubi on 08/26/2015 06:57 am
Io has many isolated mountains that are not produced by the volcanoes, but are likely produced by the moon's extremely active tectonism.
I wonder if there is any similarity?
Attachment is a Galileo image of Ionian mountains, from the February 2000 flyby of Io.
Post by: Scylla on 08/28/2015 09:57 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19881
This image, taken by NASA's Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 21, 2015.
Image Credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Image Addition Date:
2015-08-28
Post by: MattMason on 08/28/2015 11:15 pm
New image with a shiny crater.
http://photojournal.jpl.nasa.gov/catalog/PIA19881
This image, taken by NASA's Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 21, 2015.
Image Credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Image Addition Date:
2015-08-28
The more I look at this, the more I suspect ice, but that would sublimate, right? A dark surface soil with something underneath...but what?
Post by: John-H on 08/29/2015 12:10 am
New image with a shiny crater.
http://photojournal.jpl.nasa.gov/catalog/PIA19881
This image, taken by NASA's Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 21, 2015.
Image Credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Image Addition Date:
2015-08-28
The more I look at this, the more I suspect ice, but that would sublimate, right? A dark surface soil with something underneath...but what?
The grey coating is dust collected from exposure to space - which is why it is so uniform. A new crater, or a chunk thrust up from internal activity, would show what's underneath for a short time before it is covered up. ??
John
Post by: llanitedave on 08/29/2015 01:24 am
The question is, how long does this sublimation take? That could tell us how old the crater is, if the material really is ice.
Post by: DaCunha on 08/29/2015 08:45 am
Post by: Star One on 08/29/2015 10:36 am
Does anyone know why there are no images from Occator so far?
I imagine it takes longer to cover precise targets in this lower orbit.
Post by: Scylla on 08/29/2015 03:55 pm
The shiny crater looks fresher as well. The old gray craters all look quite weathered. It's possible that even within the white ice, there is a fair amount of embedded material. The ice would sublimate, leaving behind the darker residue. The crater can then darken, not from the slow accumulation of space dust, but by the much faster concentration of dark material left behind by the disappearing ice.
The question is, how long does this sublimation take? That could tell us how old the crater is, if the material really is ice.
The exposure of a subsurface layer of ice from an impact that is sublinating away is one explanation, but how does that explain the presence of several shiny spots around Ceres? That would indicate not just a single recent impact, but a bombardment. If it is not ice, why does it only show up in very specific spots scattered around Ceres. How does any of this explain "The Lonely Mountain"?
A definate puzzle. ???
Post by: zubenelgenubi on 08/29/2015 08:53 pm
Another possibility:Does anyone know why there are no images from Occator so far?
I imagine it takes longer to cover precise targets in this lower orbit.
The Dawn team does not release all the imagery as soon as possible.
Occator may be currently active--the never-officially-released imagery taken before Dawn moved to its current closer orbit suggests so.
The images, perhaps, are being withheld for a time, to allow the Dawn science team members time to study the feature more thoroughly before publishing/holding a press conference?
Just a thought,
Zubenelgenubi
Post by: DaCunha on 08/29/2015 09:03 pm
I calculated the impact velocity of a asteroid with mass 10^12 kg ( one billionth of ceres mass) to be between 500 and 600 m/s with zero initial velocity.
The guess for the mass is probably even an underestimation.
Wouldn't a rock with that velocity desintegrate at impact?
Post by: Star One on 08/31/2015 07:35 am
Another possibility:Does anyone know why there are no images from Occator so far?
I imagine it takes longer to cover precise targets in this lower orbit.
The Dawn team does not release all the imagery as soon as possible.
Occator may be currently active--the never-officially-released imagery taken before Dawn moved to its current closer orbit suggests so.
The images, perhaps, are being withheld for a time, to allow the Dawn science team members time to study the feature more thoroughly before publishing/holding a press conference?
Just a thought,
Zubenelgenubi
I did wonder that but worried that it sounded too conspiracy theory like, if you get my drift.
Post by: zubenelgenubi on 08/31/2015 02:05 pm
Does anyone know why there are no images from Occator so far?
I imagine it takes longer to cover precise targets in this lower orbit.
Another possibility:
The Dawn team does not release all the imagery as soon as possible.
Occator may be currently active--the never-officially-released imagery taken before Dawn moved to its current closer orbit suggests so.
The images, perhaps, are being withheld for a time, to allow the Dawn science team members time to study the feature more thoroughly before publishing/holding a press conference?
Just a thought,
Zubenelgenubi
I did wonder that but worried that it sounded too conspiracy theory like, if you get my drift.
Oh, I do. I hesitated to post my hypothesis, but it fits the Dawn team's behavior.
We still haven't seen an official posting of the Occator imagery that was so exciting, reported appearing in Chris Russell’s Dawn update at the Exploration Science Forum at NASA Ames on July 21.
Not wearing a tin-foil hat,
Zubenelgenubi
PS This team is not alone in such behavior. One recent example: the initial Cassini imagery of Enceladus' plumes were released as raw data and identified as such by interested observers, but Carolyn Porco and company denied the implications of said imagery until they were ready to publish.
In both cases, they are/were within their "rights" as investigators, as far as I understand it.
I might choose to play the scenario differently if I was a Principal Investigator, but I'll never be a PI, so I'll never get the chance to demonstrate such.
Post by: Scylla on 08/31/2015 05:13 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19882
This image, taken by NASA's Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 21, 2015.
Image Credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Image Addition Date:
2015-08-31
Post by: Star One on 09/01/2015 05:17 pm
This image, taken by NASA's Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 21, 2015.
http://photojournal.jpl.nasa.gov/catalog/PIA19883
Post by: cosmicvoid on 09/02/2015 04:59 am
Post by: NovaSilisko on 09/02/2015 05:24 am
Judging by the shadows in these Ceres photos, it is covered by bumps rather than craters. Is this just an illusion, and I'm misinterpreting?
Yes, it is an illusion. The sun is coming from the right, illuminating the left side of the crater walls.
Post by: yg1968 on 09/02/2015 01:41 pm
Post by: Scylla on 09/02/2015 02:58 pm
Quote
This map-projected view of Ceres was created from images taken by NASA's Dawn spacecraft during its initial approach to the dwarf planet, prior to being captured into orbit in March 2015.
Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
I can't tell from the story if this is true or false color. :(
http://www.nasa.gov/jpl/dawns-ceres-color-map-reveals-surface-diversity
Post by: Star One on 09/02/2015 04:53 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19884
Post by: Phil Stooke on 09/02/2015 05:13 pm
As it's presented there, it is false color. The three color channels are reversed for some reason, so you get a more realistic version by reversing them. But that is still extremely stretched color. If you want true color the best approximation to it is to switch from RGB to greyscale !
You have to remember that 'true' color is very subjective and difficult to be sure of - and it's not scientifically interesting. There is much more information in composites of different IR and sometimes UV wavelengths, where 'true color' means nothing anyway.
Post by: punder on 09/02/2015 05:15 pm
Judging by the shadows in these Ceres photos, it is covered by bumps rather than craters. Is this just an illusion, and I'm misinterpreting?
I wonder how many people have this problem? I certainly do... as I child I mistakenly trained my eyes to see bumps instead of craters on the giant National Geographic moon map. Have had trouble with it ever since.
Post by: yg1968 on 09/02/2015 07:20 pm
"I can't tell from the story if this is true or false color."
As it's presented there, it is false color. The three color channels are reversed for some reason, so you get a more realistic version by reversing them. But that is still extremely stretched color. If you want true color the best approximation to it is to switch from RGB to greyscale !
You have to remember that 'true' color is very subjective and difficult to be sure of - and it's not scientifically interesting. There is much more information in composites of different IR and sometimes UV wavelengths, where 'true color' means nothing anyway.
It's false color but I imagine that it would probably not be that hard to turn it into true colours. There is some images in true colour but they are only of a very small portion of the planet.
For example, see this one (the left ones are true colour):
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19316
And these ones (the middle ones are true colour):
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19608
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA19571
Post by: Star One on 09/02/2015 08:43 pm
Judging by the shadows in these Ceres photos, it is covered by bumps rather than craters. Is this just an illusion, and I'm misinterpreting?
I wonder how many people have this problem? I certainly do... as I child I mistakenly trained my eyes to see bumps instead of craters on the giant National Geographic moon map. Have had trouble with it ever since.
I have the same trouble. Take that latest image from today took me a while to realise that was a crater in it with a landslide on one side.
Post by: Baranquilla on 09/02/2015 09:36 pm
Judging by the shadows in these Ceres photos, it is covered by bumps rather than craters. Is this just an illusion, and I'm misinterpreting?
I wonder how many people have this problem? I certainly do... as I child I mistakenly trained my eyes to see bumps instead of craters on the giant National Geographic moon map. Have had trouble with it ever since.
I have the same trouble. Take that latest image from today took me a while to realise that was a crater in it with a landslide on one side.
@ cosmicvoid, punder, Star One
This actually isn't 'your fault'. On shaded relief maps the light is chosen to come from the upper left corner (NW) if you will, and thus cast shadows on the SE flank of mountains. Your brain gets trained to recognise this and to use that as a reference (at least mine is a bit). Sometimes if you flip the image 180 degrees the problem will get solved. This is of course no shaded relief map but an actual picture so the differential reflectance of surface materials also matter.
Post by: Star One on 09/02/2015 11:04 pm
Judging by the shadows in these Ceres photos, it is covered by bumps rather than craters. Is this just an illusion, and I'm misinterpreting?
I wonder how many people have this problem? I certainly do... as I child I mistakenly trained my eyes to see bumps instead of craters on the giant National Geographic moon map. Have had trouble with it ever since.
I have the same trouble. Take that latest image from today took me a while to realise that was a crater in it with a landslide on one side.
@ cosmicvoid, punder, Star One
This actually isn't 'your fault'. On shaded relief maps the light is chosen to come from the upper left corner (NW) if you will, and thus cast shadows on the SE flank of mountains. Your brain gets trained to recognise this and to use that as a reference (at least mine is a bit). Sometimes if you flip the image 180 degrees the problem will get solved. This is of course no shaded relief map but an actual picture so the differential reflectance of surface materials also matter.
Thank you for the explanation.
As a side point it really does look like they aren't going to show us Occator?
Post by: Nomadd on 09/03/2015 12:26 am
When they get to it. It is a two month long mapping orbit. It's not like earlier ones when they could get half the planet in one shot. I thought they were getting the whole surface four times from different angles in this orbit, so Occator should be available soon.
As a side point it really does look like they aren't going to show us Occator?
The LAMO could be as much as two months between shots of a particular area.
Post by: Scylla on 09/03/2015 04:26 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19885
This image, taken by NASA's Dawn spacecraft, shows a portion of Ceres at mid-latitudes from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 21, 2015.
Image Credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Image Addition Date:
2015-09-03
Also:
NASA's Dawn Mission @NASA_Dawn
Update: I have completed half of the observations for my second map of #Ceres at this orbital altitude
https://twitter.com/NASA_Dawn/status/639227942267056128
Post by: Star One on 09/03/2015 07:41 pm
Post by: Scylla on 09/03/2015 08:03 pm
Again it took me a while to see that as a crater. By the way that Twitter link was doubly useful as it went into discuss the lack of Occator images.After closer study of the shadows, I think what I first took to be ridges, are in fact cracks. Still wonder what caused them.
Post by: Baranquilla on 09/04/2015 11:16 am
When they get to it. It is a two month long mapping orbit. It's not like earlier ones when they could get half the planet in one shot. I thought they were getting the whole surface four times from different angles in this orbit, so Occator should be available soon.
As a side point it really does look like they aren't going to show us Occator?
The LAMO could be as much as two months between shots of a particular area.
Two months (60 days) and four repeats means a ground repeat time of 15 days, very comparable to Landsat or most mid resolution earth obseration sensors. At least for this altitude
Post by: Star One on 09/04/2015 05:17 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19886
Lot of light material and strange bubble like features.
Post by: NovaSilisko on 09/04/2015 06:40 pm
Here's today's image.
http://photojournal.jpl.nasa.gov/catalog/PIA19886
Lot of light material and strange bubble like features.
Bubble features? Are you sure you aren't just perceiving inverted terrain relief in the craters, like happened earlier in the thread? Or am I missing something you've spotted?
Post by: PahTo on 09/04/2015 06:45 pm
Ah, the ol' frame of reference issue again. If the light source is from the upper left of frame, they're bubbles. If light source from lower right of frame, they're craters. Do we consider upper left to be "NW"?
Post by: Scylla on 09/04/2015 07:04 pm
Post by: NovaSilisko on 09/04/2015 07:17 pm
Ah, the ol' frame of reference issue again. If the light source is from the upper left of frame, they're bubbles. If light source from lower right of frame, they're craters. Do we consider upper left to be "NW"?
It's funny. I've never had that problem, really. I think it might be because my brain knows I'm looking at craters, so it adjusts accordingly to make them be perceived like pits.
Post by: Lee Jay on 09/04/2015 08:06 pm
Post by: Star One on 09/04/2015 09:29 pm
Here's today's image.
http://photojournal.jpl.nasa.gov/catalog/PIA19886
Lot of light material and strange bubble like features.
Bubble features? Are you sure you aren't just perceiving inverted terrain relief in the craters, like happened earlier in the thread? Or am I missing something you've spotted?
Who knows I give up with the blasted confusing lighting on these images. I don't know if it's something to do with my eyes but I have great difficulty with the perception of these images.
Post by: the_other_Doug on 09/05/2015 01:08 am
Ah, the ol' frame of reference issue again. If the light source is from the upper left of frame, they're bubbles. If light source from lower right of frame, they're craters. Do we consider upper left to be "NW"?
It's funny. I've never had that problem, really. I think it might be because my brain knows I'm looking at craters, so it adjusts accordingly to make them be perceived like pits.
I find I have the knack of changing the frame of reference almost at will. When I look at a finely cratered surface like this, since I'm expecting to see craters, I usually see craters. But I can just sort of, I dunno, switch something in my head, and make myself see them as bumps. And back. If I get stuck in reverse-relief, I can break it by just painting in my head where the Sun is located, and it flips right into place.
It's sort of like something Story Musgrave had noted -- when he was in orbit, he had the ability, inside his head, to switch perceptions, at will, between feeling he was floating at rest with his immediate surroundings, and feeling like he and his surroundings were falling. The falling sensation could be disconcerting, but it was also useful to him -- and he was able to talk some of his crewmates through getting to where they could switch perceptions like that, too.
I don't think it has anything to do with someone having superior talents or anything, I think it just has to do with the way your brain is wired. I know there are tons of things other people think are really simple that I find challenging, too.
Getting back to topic, I think we're seeing a lot of very interesting surfaces on Ceres. Everything that isn't a fairly well-defined crater seems to be made up of covering layers over old craters, giving us ghost craters of varying levels of degradation all over the place. In some places, maybe big craters have only been covered over with one resurfacing event, while in others, perhaps two or three layers of new material are covering over old, heavily cratered terrain. This all speaks to a lot of resurfacing events with punctuating cratering events (pardon the pun).
Fascinating little world...
Post by: Star One on 09/08/2015 07:50 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19887
This has just been posted over at UMS forum, make of it what you will.
Quote
images of spot 5 are being held from the public because of a peer review pending paper. Im told that the new pictures are wonderful and reveal alot the spots appear to be resembling a lake bed and some sort of dusting material all over the place in and out. The material is still not known..tho its openly being speculated its some sort of new element. something we dont know about yet. It may be many more weeks before occator images are released.
Post by: llanitedave on 09/09/2015 03:11 am
Post by: the_other_Doug on 09/09/2015 03:13 am
Today's image I've given up trying to say what are craters and what aren't here.
http://photojournal.jpl.nasa.gov/catalog/PIA19887
This has just been posted over at UMS forum, make of it what you will.Quoteimages of spot 5 are being held from the public because of a peer review pending paper. Im told that the new pictures are wonderful and reveal alot the spots appear to be resembling a lake bed and some sort of dusting material all over the place in and out. The material is still not known..tho its openly being speculated its some sort of new element. something we dont know about yet. It may be many more weeks before occator images are released.
This has since been clarified in the Dawn team's twitter account that the embargo, while a paper submitted to the journal Nature is out for peer review, does not apply to images. And says that Occator images will be out very soon.
https://twitter.com/NASA_Dawn/status/641420466029113344 (https://twitter.com/NASA_Dawn/status/641420466029113344)
Post by: Star One on 09/09/2015 09:16 am
Post by: Silmfeanor on 09/09/2015 02:40 pm
http://www.jpl.nasa.gov/news/news.php?feature=4714 (http://www.jpl.nasa.gov/news/news.php?feature=4714)
http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA19889 (http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA19889)
Post by: llanitedave on 09/09/2015 05:35 pm
Post by: acsawdey on 09/09/2015 05:44 pm
Post by: notsorandom on 09/09/2015 05:46 pm
All right, that just makes it worse. What ARE those things??????One thing is for sure. It is looking less like an alien spaceship with every higher resolution picture. I will likely be losing that particular bet.
Post by: Star One on 09/09/2015 11:24 pm
Post by: NovaSilisko on 09/09/2015 11:53 pm
All right, that just makes it worse. What ARE those things??????One thing is for sure. It is looking less like an alien spaceship with every higher resolution picture. I will likely be losing that particular bet.
You never know, maybe it'll turn out to be a big city, for little Cerean bugs made out of salt. Not sure if that would qualify under the terms of your bet, though.
Post by: zubenelgenubi on 09/10/2015 03:29 am
:)"They" could be observing Earth, the "ugly bags of mostly water" inhabiting it, and the alien robot now reconnoitering their world. :)All right, that just makes it worse. What ARE those things??????One thing is for sure. It is looking less like an alien spaceship with every higher resolution picture. I will likely be losing that particular bet.
You never know, maybe it'll turn out to be a big city, for little Cerean bugs made out of salt. Not sure if that would qualify under the terms of your bet, though.
Post by: NovaSilisko on 09/10/2015 03:51 am
:)"They" could be observing Earth, the "ugly bags of mostly water" inhabiting it, and the alien robot now reconnoitering their world. :)
Some time in the future...
"And that's how it was for the next ten nights. A flare, spurting out from Ceres. Bright green, drawing a green mist behind it. A beautiful, but somehow disturbing sight... Russell, the principal investigator, assured me we were in no danger. He was convinced that there could be no living thing on that remote, forbidding, dwarf planet..."
[begin menacing bassline]
Post by: Stan-1967 on 09/10/2015 05:06 am
When zooming in on the center feature, it appears to be a near perfect paraboloid mountain. The pixels gray out on the left hand side near perfect to my guess of where the incident sunlight is coming from.
The center feature appears to be located inside of circular fractured region about 15km in diameter ( if my pixel counting is close to accurate at 140 meters per pixel )
The fractures, and my take on the sunlight/shadows around the circular area, remind me of the surface depressions seen after detonations of nuclear weapons burried deep undergound.
I also noted a very dark feature that is occupies an area just over 3x3 pixels about 15.5 km from the center peak. The location of the pixels suggest to me that I am seeing a big hole in the ground, not a crater. It reminded me of the "sunroof" features seen on the flanks of Martian volcanoes where the ground had collapsed over an empty lava tube. I recall these have been found on the moon as well. I will try to dig up some pics from internet sources.
So what to make of it? A collapsed roof of a hollow underground chamber adjacent to where a very uniform extrusion of "something" is pushing up from the center of the crater floor.
Post by: Stan-1967 on 09/10/2015 05:31 am
Here is an annotated image I made of the Ceres bright spot, as well as images from Mars and the Moon with skylight openings over lavatubes
Post by: RotoSequence on 09/10/2015 05:35 am
Post by: meekGee on 09/10/2015 06:12 am
It's not impossible for something to sublimate for years, but I like the direction of a continuous process better.
Post by: Stan-1967 on 09/10/2015 06:18 am
Post by: Star One on 09/10/2015 09:05 am
Lava tubes with skylights would be exciting, but the dark triangle is a spec on Dawn's lens. :(
I've seen that triangle a number of times in different pictures, is it an imperfection that's developed in Dawn's camera?
Post by: mcgyver on 09/10/2015 09:06 am
http://photojournal.jpl.nasa.gov/catalog/PIA19890 (http://photojournal.jpl.nasa.gov/catalog/PIA19890)
(I suggest "bounce playing" forward/backward in Virtualdub)
The "big white circle" defintely appears to be into a depression in terrain.
A 6x6 km frozen lake, created when the impactor reached the underground water? But a weird shadow on the left part of the 6x6 km hole makes think to a frozen BUBBLE! ???
Post by: Star One on 09/10/2015 09:10 am
Post by: mcgyver on 09/10/2015 09:23 am
Post by: mcgyver on 09/10/2015 11:59 am
Small hot source on Stromboli volcano (Italy).
Video:
http://footage.framepool.com/en/shot/139007303-stromboli-vulcano-sulfur-hole-form-volcanic-rock (http://footage.framepool.com/en/shot/139007303-stromboli-vulcano-sulfur-hole-form-volcanic-rock)
Post by: notsorandom on 09/10/2015 01:57 pm
Post by: meekGee on 09/10/2015 02:30 pm
Wouldn't surprise me if we don't see at least one proposal for a Ceres lander in the next round of Discovery or New Horizons.Yup, not at all.
If this is indeed water (IF!) then this is a very important resource for beyond Mars missions.
I always liked Ceres.
I wonder if Dragon can land there with regular Dracos and modified legs.
Post by: Zed_Noir on 09/10/2015 02:40 pm
All right, that just makes it worse. What ARE those things??????One thing is for sure. It is looking less like an alien spaceship with every higher resolution picture. I will likely be losing that particular bet.
Well there is the wacky idea in Sci-Fi lore that I recalled of a large spaceship build out of ice. However you are probably right in your bet forcasting.
Post by: Zed_Noir on 09/10/2015 03:02 pm
Wouldn't surprise me if we don't see at least one proposal for a Ceres lander in the next round of Discovery or New Horizons.Yup, not at all.
If this is indeed water (IF!) then this is a very important resource for beyond Mars missions.
I always liked Ceres.
I wonder if Dragon can land there with regular Dracos and modified legs.
If the Dawn spacecraft will continue to be operational for a few more years. You could send a small impacter to kick up some stuff for observation. Rigged up something with a COTS optical terminal guidance package and attitude RCS system.
Post by: Nomadd on 09/10/2015 04:05 pm
Occator looks like many other craters on Ceres, steep walls and all. So I would be hesitant to say that it is due to a geologic process like subsidence or a collapsed caldera rather than an impact. The fact that the brightest of the bright spots is in the center of Occator is begging for a connection between the crater and the bright spot. However what ever created the bright spots may have occurred after or during the creation of the crater and not be a cause of the crater itself.The middle of an impact crater does seem like a good case for a weak spot in the outer surface, allowing for this talcum powder or whatever volcano, but looking at the smaller craters in the big one, the big one must be pretty ancient. Several hundred million years seems like a long time for this outlet to stay active.
Post by: Nomadd on 09/10/2015 04:10 pm
If it does turn out to be an alien city, that'll be a great way to say hello. Are you trying to get us all vaporized?
If the Dawn spacecraft will continue to be operational for a few more years. You could send a small impacter to kick up some stuff for observation. Rigged up something with a COTS optical terminal guidance package and attitude RCS system.
Post by: Zed_Noir on 09/10/2015 04:27 pm
If it does turn out to be an alien city, that'll be a great way to say hello. Are you trying to get us all vaporized?
If the Dawn spacecraft will continue to be operational for a few more years. You could send a small impacter to kick up some stuff for observation. Rigged up something with a COTS optical terminal guidance package and attitude RCS system.
Not that much difference between the occasional strike from celestial junk and an impacter. Judging from the number of craters on Ceres, it is unlikely to be inhabited. Of course if there are aliens, then I guess they will deal with the impacter like with any space object heading their way. Since the Dawn probe have not been vaporized yet, there is no one there. ;)
Post by: Star One on 09/10/2015 04:31 pm
Post by: nadreck on 09/10/2015 04:36 pm
Wouldn't surprise me if we don't see at least one proposal for a Ceres lander in the next round of Discovery or New Horizons.Yup, not at all.
If this is indeed water (IF!) then this is a very important resource for beyond Mars missions.
I always liked Ceres.
I wonder if Dragon can land there with regular Dracos and modified legs.
There are 4 draco's on the trunk pointing in the direction needed - that would be 1600 newtons of thrust, surface gravity of Ceres is 0.27m/s2 so 1600 / .27 = 5926 kg of mass that it could hover at the surface. I don't know the angles or numbers of draco's pointing in roughly the right direction on the capsule to calculate the loss due to the angle. Suffice it to say, I don't think that there is as much capacity as the trunk has, so for certain <10,000 kgs - practically I would say not to try it with more than 4000 landed mass between trunk and capsule.
Post by: notsorandom on 09/10/2015 05:27 pm
Well that is the conundrum if you will. Occator seems to be rather old. The general thinking is that the space environment and UV radiation will darken exposed surface material over a long timeline. Hence the Ceres's uniformly dark surface. The bright spots within Occator are either of a material which doesn't react space weather and have been there millions if not billions of year or it is more recent material. The Dawn PI's vague statement about haze in the crater is indicative of not only a recent (geologically speaking) source for the bright material but one that currently ongoing. I have to agree that there is either a thinning of the crust or some other type of effect from that impact to have encourage the bright spots to show up in Occator. What ever can explain why an ancient crater would have a modern geologic process occurring in it may not be due to aliens but it sure is interesting and bizarre. Dawn carries the VIR and GRaND instruments which should help figure out what that bright material is.Occator looks like many other craters on Ceres, steep walls and all. So I would be hesitant to say that it is due to a geologic process like subsidence or a collapsed caldera rather than an impact. The fact that the brightest of the bright spots is in the center of Occator is begging for a connection between the crater and the bright spot. However what ever created the bright spots may have occurred after or during the creation of the crater and not be a cause of the crater itself.The middle of an impact crater does seem like a good case for a weak spot in the outer surface, allowing for this talcum powder or whatever volcano, but looking at the smaller craters in the big one, the big one must be pretty ancient. Several hundred million years seems like a long time for this outlet to stay active.
Post by: zubenelgenubi on 09/10/2015 05:54 pm
Well that is the conundrum if you will. Occator seems to be rather old. The general thinking is that the space environment and UV radiation will darken exposed surface material over a long timeline. Hence the Ceres's uniformly dark surface. The bright spots within Occator are either of a material which doesn't react space weather and have been there millions if not billions of year or it is more recent material. The Dawn PI's vague statement about haze in the crater is indicative of not only a recent (geologically speaking) source for the bright material but one that currently ongoing. I have to agree that there is either a thinning of the crust or some other type of effect from that impact to have encourage the bright spots to show up in Occator. What ever can explain why an ancient crater would have a modern geologic process occurring in it may not be due to aliens but it sure is interesting and bizarre. Dawn carries the VIR and GRaND instruments which should help figure out what that bright material is.Occator looks like many other craters on Ceres, steep walls and all. So I would be hesitant to say that it is due to a geologic process like subsidence or a collapsed caldera rather than an impact. The fact that the brightest of the bright spots is in the center of Occator is begging for a connection between the crater and the bright spot. However what ever created the bright spots may have occurred after or during the creation of the crater and not be a cause of the crater itself.The middle of an impact crater does seem like a good case for a weak spot in the outer surface, allowing for this talcum powder or whatever volcano, but looking at the smaller craters in the big one, the big one must be pretty ancient. Several hundred million years seems like a long time for this outlet to stay active.
2 thoughts:
The Tharsis volcanoes on Mars appear to have been active over most of the life of the planet. Volcanoes intermittently active over millions or billions of years, in and of themselves, are not out of the question.
The GRaND instrument needs to be as close as possible to the surface to gather useful amounts of data--so we'll be waiting for the drop to LAMO for this instrument to excel.
Post by: Bob Shaw on 09/10/2015 06:29 pm
My take on this is that Ceres isn't big enough to have 'proper' volcanic processes; instead. I think we're seeing the result of sub-surface volatiles being released into vacuo, perhaps associated with warm spots and possibly set running by impacts. The Moon appears to have a crust with large amounts of 'mega breccia' underlying the landforms; perhaps Ceres is similar, and has voids and pits of frozen volatiles which are released every now and again.
Your mileage may vary.
Post by: notsorandom on 09/10/2015 06:47 pm
Post by: zubenelgenubi on 09/10/2015 08:44 pm
The problem with sporadic volcanic activity i.e. intermittently active over millions of year is the low chance to catch it in action. Which apparently Dawn has done. Its not just the bright material on the ground which may be able to last for quite some time but the haze seen in the crater which cannot persist. Dawn could have done the equivalent of winning the lottery visiting Ceres during a rare geologic event, though its unlikely.
Another thought/question: Could Occator be the one currently active location, with other bright spots marking previously active locations?
Activity bubbles up in one location for X thousand/million years, then ceases. Meanwhile, activity at another location commences for another Y thousand/million years, and so on.
Post by: Star One on 09/10/2015 10:10 pm
The problem with sporadic volcanic activity i.e. intermittently active over millions of year is the low chance to catch it in action. Which apparently Dawn has done. Its not just the bright material on the ground which may be able to last for quite some time but the haze seen in the crater which cannot persist. Dawn could have done the equivalent of winning the lottery visiting Ceres during a rare geologic event, though its unlikely.
Though it's unlikely doesn't mean it's impossible, these things do happen.
Post by: mcgyver on 09/11/2015 06:37 am
If it does turn out to be an alien city, that'll be a great way to say hello. Are you trying to get us all vaporized?
If the Dawn spacecraft will continue to be operational for a few more years. You could send a small impacter to kick up some stuff for observation. Rigged up something with a COTS optical terminal guidance package and attitude RCS system.
For some reasones, Ceres is widely present in fiction:
https://en.wikipedia.org/wiki/Ceres_(dwarf_planet)_in_fiction
Post by: meekGee on 09/11/2015 08:16 am
http://www.universetoday.com/122286/do-ceres-bizarre-bright-spots-seen-in-dazzling-new-close-ups-arise-from-water-leakage-dawn-science-team-talks-to-ut/#more-122286
They say salt, not ice.
Water carries the salt out, evaporates, ta da.
The albedo they are measuring is 0.5, not 1.0.
Not clear from the article whether the process is active today.
Post by: Star One on 09/11/2015 09:46 am
Post by: mcgyver on 09/11/2015 11:58 am
So that's effectively a confirmation of the third salty ocean outside Earth following Europa & Enceladus.I recently saw an image grouping around half a dozen celestial bodies carrying an hidden ocean.
Don't remember where.
Post by: notsorandom on 09/11/2015 01:14 pm
So that's effectively a confirmation of the third salty ocean outside Earth following Europa & Enceladus.The amount of liquid brine below the surface at any given time may be quite small. Without knowing how this is created its hard to say. It could be like the brine flows we have seen on the crater walls at Mars. A bit of ice melts and seeps out.
Post by: notsorandom on 09/11/2015 01:22 pm
UT has an interview with the Dawn team:I think the author is wrong when he says there has been no evidence of current activity. Dr. Russell mentioned that the team saw haze at a recent conference (or has that been retracted?). Also Herschel detected a water vapor plume a while back. There is evidence. It may be incomplete, misleading, or wrong but there is some evidence. The question in my mind is how long do these salts last on the surface? The longer they can remain bright then the longer ago the activity which deposited them there can be.
http://www.universetoday.com/122286/do-ceres-bizarre-bright-spots-seen-in-dazzling-new-close-ups-arise-from-water-leakage-dawn-science-team-talks-to-ut/#more-122286
They say salt, not ice.
Water carries the salt out, evaporates, ta da.
The albedo they are measuring is 0.5, not 1.0.
Not clear from the article whether the process is active today.
Post by: Bob Shaw on 09/11/2015 01:36 pm
So that's effectively a confirmation of the third salty ocean outside Earth following Europa & Enceladus.The amount of liquid brine below the surface at any given time may be quite small. Without knowing how this is created its hard to say. It could be like the brine flows we have seen on the crater walls at Mars. A bit of ice melts and seeps out.
See my post above - we may be seeing isolated sources of volatiles (which may not be H20) which are released as a result of impacts, general settling or whatever. Things are far too early to claim a salty ocean is responsible.
When the orbital data from Dawn is properly analysed we may have a better idea of the mass distribution within Ceres, which will give us more leads.
Post by: Star One on 09/11/2015 07:51 pm
HAMO Image 14
For some reason they've skipped HAMO Image 13.
Post by: zubenelgenubi on 09/11/2015 09:08 pm
So that's effectively a confirmation of the third salty ocean outside Earth following Europa & Enceladus.The amount of liquid brine below the surface at any given time may be quite small. Without knowing how this is created its hard to say. It could be like the brine flows we have seen on the crater walls at Mars. A bit of ice melts and seeps out.
See my post above - we may be seeing isolated sources of volatiles (which may not be H20) which are released as a result of impacts, general settling or whatever. Things are far too early to claim a salty ocean is responsible.
When the orbital data from Dawn is properly analysed we may have a better idea of the mass distribution within Ceres, which will give us more leads.
Cerean mantle briny deeps? Cerean mascons? What a wonderful world Ceres could be!
Post by: Star One on 09/12/2015 08:38 pm
Post by: sghill on 09/12/2015 09:20 pm
We don't know what dust will do in that environment on top of an icy surface. For example- hypothetically speaking, the central mound could have been covered by dust like the rest of the surface for millenia, and then the dust was shed due to a small ceresquake when something splattered nearby creating the other bright spots.
We simply don't know.
Post by: John-H on 09/13/2015 12:21 am
I think it's important not to terrapomorphizetm the behavior of features on Ceres.
We don't know what dust will do in that environment on top of an icy surface. For example- hypothetically speaking, the central mound could have been covered by dust like the rest of the surface for millenia, and then the dust was shed due to a small ceresquake when something splattered nearby creating the other bright spots.
We simply don't know.
Why is the entire surface, except for the white spots, the exact same colour and texture? I'm sure the base material is not that uniform. It looks like an even coating of "space dust", and the spots are just places with steep slopes or new craters where we can see through the dust.
We need a mission to sweep off the dust to see what Ceres is really like :)
John
Post by: Bob Shaw on 09/13/2015 01:00 am
I think it's important not to terrapomorphizetm the behavior of features on Ceres.
We don't know what dust will do in that environment on top of an icy surface. For example- hypothetically speaking, the central mound could have been covered by dust like the rest of the surface for millenia, and then the dust was shed due to a small ceresquake when something splattered nearby creating the other bright spots.
We simply don't know.
True, but Terrestrial geomorphology is a good touchstone. We sometimes fail to consider that the Earth is also subject to planetary-scale events and processes, however!
Post by: NovaSilisko on 09/17/2015 05:51 pm
http://photojournal.jpl.nasa.gov/catalog/PIA19895
Post by: Star One on 09/17/2015 05:58 pm
Here's today's image HAMO 18.
http://photojournal.jpl.nasa.gov/catalog/PIA19896
Post by: llanitedave on 09/17/2015 07:47 pm
Post by: Star One on 09/30/2015 09:05 pm
Mysteries and insights about Ceres are being discussed this week at the European Planetary Science Conference in Nantes, France. NASA's Dawn spacecraft is providing scientists with tantalizing views and other data about the intriguing dwarf planet that they continue to analyze.
"Ceres continues to amaze, yet puzzle us, as we examine our multitude of images, spectra and now energetic particle bursts," said Chris Russell, Dawn principal investigator at the University of California, Los Angeles.
A new color-coded topographic map shows more than a dozen recently approved names for features on Ceres, all eponymous for agricultural spirits, deities and festivals from cultures around the world. These include Jaja, after the Abkhazian harvest goddess, and Ernutet, after the cobra-headed Egyptian harvest goddess. A 12-mile (20-kilometer) diameter mountain near Ceres' north pole is now called Ysolo Mons, for an Albanian festival that marks the first day of the eggplant harvest.
Hints at Ceres
This map-projected view of Ceres was created from images taken by NASA's Dawn spacecraft during its high-altitude mapping orbit, in August and September, 2015. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
› Full image and caption
Mysteries and insights about Ceres are being discussed this week at the European Planetary Science Conference in Nantes, France. NASA's Dawn spacecraft is providing scientists with tantalizing views and other data about the intriguing dwarf planet that they continue to analyze.
"Ceres continues to amaze, yet puzzle us, as we examine our multitude of images, spectra and now energetic particle bursts," said Chris Russell, Dawn principal investigator at the University of California, Los Angeles.
A new color-coded topographic map shows more than a dozen recently approved names for features on Ceres, all eponymous for agricultural spirits, deities and festivals from cultures around the world. These include Jaja, after the Abkhazian harvest goddess, and Ernutet, after the cobra-headed Egyptian harvest goddess. A 12-mile (20-kilometer) diameter mountain near Ceres' north pole is now called Ysolo Mons, for an Albanian festival that marks the first day of the eggplant harvest.
Guess what the bright spots are
Another new Ceres map, in false color, enhances compositional differences present on the surface. The variations are more subtle than on Vesta, Dawn's previous port of call. Color-coded topographic images of Occator (oh-KAH-tor) crater, home of Ceres' brightest spots, and a puzzling, cone-shaped 4-mile-high (6-kilometer-high) mountain, are also available. Scientists are still trying to identify processes that could produce these and other unique Cerean phenomena.
"The irregular shapes of craters on Ceres are especially interesting, resembling craters we see on Saturn's icy moon Rhea," said Carol Raymond, Dawn's deputy principal investigator based at NASA's Jet Propulsion Laboratory, Pasadena, California. "They are very different from the bowl-shaped craters on Vesta."
A surprising bonus observation came from Dawn's gamma ray and neutron spectrometer. The instrument detected three bursts of energetic electrons that may result from the interaction between Ceres and radiation from the sun. The observation isn't yet fully understood, but may be important in forming a complete picture of Ceres.
"This is a very unexpected observation for which we are now testing hypotheses," Russell said.
Dawn is currently orbiting Ceres at an altitude of 915 miles (1,470 kilometers), and the spacecraft will image the entire surface of the dwarf planet up to six times in this phase of the mission. Each imaging cycle takes 11 days.
Starting in October and continuing into December, Dawn will descend to its lowest and final orbit, an altitude of 230 miles (375 kilometers). The spacecraft will continue imaging Ceres and taking other data at higher resolutions than ever before at this last orbit. It will remain operational at least through mid-2016.
Dawn made history as the first mission to reach a dwarf planet, and the first to orbit two distinct extraterrestrial targets, when it arrived at Ceres on March 6, 2015. It conducted extensive observations of Vesta in 2011 and 2012.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
Updated on Sept. 30th at 1 p.m. PDT with corrected height of the cone-shaped mountain.
http://dawn.jpl.nasa.gov/news/news-detail.html?id=4725
Post by: cosmicvoid on 10/01/2015 05:54 am
Dawn Team Shares New Maps and Insights about Ceres
Mysteries and insights about Ceres are being discussed this week at the European Planetary Science Conference in Nantes, France. NASA's Dawn spacecraft is providing scientists with tantalizing views and other data about the intriguing dwarf planet that they continue to analyze.
"Ceres continues to amaze, yet puzzle us, as we examine our multitude of images, spectra and now energetic particle bursts," said Chris Russell, Dawn principal investigator at the University of California, Los Angeles.
A new color-coded topographic map shows more than a dozen recently approved names for features on Ceres, all eponymous for agricultural spirits, deities and festivals from cultures around the world. These include Jaja, after the Abkhazian harvest goddess, and Ernutet, after the cobra-headed Egyptian harvest goddess. A 12-mile (20-kilometer) diameter mountain near Ceres' north pole is now called Ysolo Mons, for an Albanian festival that marks the first day of the eggplant harvest.
Hints at Ceres
This map-projected view of Ceres was created from images taken by NASA's Dawn spacecraft during its high-altitude mapping orbit, in August and September, 2015. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
› Full image and caption
Mysteries and insights about Ceres are being discussed this week at the European Planetary Science Conference in Nantes, France. NASA's Dawn spacecraft is providing scientists with tantalizing views and other data about the intriguing dwarf planet that they continue to analyze.
"Ceres continues to amaze, yet puzzle us, as we examine our multitude of images, spectra and now energetic particle bursts," said Chris Russell, Dawn principal investigator at the University of California, Los Angeles.
A new color-coded topographic map shows more than a dozen recently approved names for features on Ceres, all eponymous for agricultural spirits, deities and festivals from cultures around the world. These include Jaja, after the Abkhazian harvest goddess, and Ernutet, after the cobra-headed Egyptian harvest goddess. A 12-mile (20-kilometer) diameter mountain near Ceres' north pole is now called Ysolo Mons, for an Albanian festival that marks the first day of the eggplant harvest.
Guess what the bright spots are ... snip.
Some duplication.
Post by: Star One on 10/01/2015 06:25 am
Post by: Star One on 10/02/2015 10:24 pm
Quote
"We believe this is a huge salt deposit," Dawn's principal investigator Chris Russell told a crowd of scientists Monday at the European Planetary Science Congress in Nantes, France, in a talk that was posted online Thursday. "We know it's not ice and we're pretty sure it's salt, but we don't know exactly what salt at the present time. "
Russell also briefly described the strange, tall mountain that has been observed on Ceres, sporting bright streaks along its sides that he says are "probably salt again." He said the unnamed peak may have another sibling mountain on the dwarf planet, but Dawn has not yet acquired a good view of that one.
Finally, Russell raised the possibility that any liquid water inside Ceres might be able to harbor life. He said the possibility is one reason that there will be no attempt to land Dawn on Ceres, so as to avoid potentially contaminating the environment with our Earth cooties (my term, not Russell's).
http://www.cnet.com/news/nasa-thinks-it-knows-what-ceres-mysterious-bright-spots-are-made-of/
There's a video of the full talk on the link.
Post by: Blackstar on 10/03/2015 07:53 pm
Well, I guess that means we won't be settling the solar system!
Post by: eeergo on 10/03/2015 08:40 pm
http://www.uahirise.org/ESP_041208_1755 (http://www.uahirise.org/ESP_041208_1755)
Post by: MattMason on 10/03/2015 09:07 pm
"We believe this is a huge salt deposit," Dawn's principal investigator Chris Russell told a crowd of scientists Monday at the European Planetary Science Congress in Nantes, France, in a talk that was posted online Thursday. "We know it's not ice and we're pretty sure it's salt, but we don't know exactly what salt at the present time."
Well, I guess that means we won't be settling the solar system!
I don't know. Maybe not humans. But once deer become sentient, that's a serious celestial salt lick to visit.
Post by: Alpha_Centauri on 10/03/2015 10:47 pm
Post by: meekGee on 10/04/2015 02:21 am
It might be as simple as drilling down a little bit...
Post by: llanitedave on 10/04/2015 03:28 am
Post by: Star One on 10/04/2015 12:25 pm
The salt could have been deposited when salty water evaporated.
It might be as simple as drilling down a little bit...
Seems the most possible answer.
Post by: zubenelgenubi on 10/04/2015 09:15 pm
Carthage?Following this line of thought, where are the Romans? They certainly seem to have soundly defeated the Cerean slugs.
Perhaps in a forum, someplace else and sometime else, an alien orator ended all his/her/its speeches with the alien equivalent of "Carthago delenda est."
Post by: Targeteer on 10/27/2015 12:40 am
Dawn Mission Status Report
NASA's Dawn spacecraft fired up its ion engine on Friday, Oct. 23, to begin its journey toward its fourth and final science orbit at dwarf planet Ceres. The spacecraft completed two months of observations from an altitude of 915 miles (1,470 kilometers) and transmitted extensive imagery and other data to Earth.
The spacecraft is now on its way to the final orbit of the mission, called the low-altitude mapping orbit. Dawn will spend more than seven weeks descending to this vantage point, which will be less than 235 miles (380 kilometers) from the surface of Ceres. In mid-December, Dawn will begin taking observations from this orbit, including images at a resolution of 120 feet (35 meters) per pixel.
Of particular interest to the Dawn team is Occator crater, home to Ceres' bright spots. A new mosaic of images from Dawn's third science orbit highlights the crater and surrounding terrain.
More information on the Dawn mission is online at:
http://www.nasa.gov/dawn
http://dawn.jpl.nasa.gov
Post by: Star One on 12/04/2015 07:02 am
http://www.jpl.nasa.gov/spaceimages/images/largesize/PIA20132_hires.jpg
Post by: J-V on 12/04/2015 07:11 am
Post by: KelvinZero on 12/04/2015 09:31 am
DailyMail link (http://www.dailymail.co.uk/sciencetech/article-3228382/The-alien-spots-Ceres-revealed-unprecedented-Dawn-probe-captures-stunning-new-images-mysterious-features.html)
(I was wondering if they had applied some magic image processing to make it prettier, or do we actually have this detail?)
Post by: NovaSilisko on 12/04/2015 09:57 am
Post by: Star One on 12/04/2015 12:04 pm
Post by: eeergo on 12/06/2015 10:02 pm
Post by: Star One on 12/09/2015 05:49 pm
New Clues to Ceres' Bright Spots and Origins
Quote
Ceres reveals some of its well-kept secrets in two new studies in the journal Nature, thanks to data from NASA's Dawn spacecraft. They include highly anticipated insights about mysterious bright features found all over the dwarf planet's surface.
In one study, scientists identify this bright material as a kind of salt. The second study suggests the detection of ammonia-rich clays, raising questions about how Ceres formed.
About the Bright Spots
Ceres has more than 130 bright areas, and most of them are associated with impact craters. Study authors, led by Andreas Nathues at Max Planck Institute for Solar System Research, Göttingen, Germany, write that the bright material is consistent with a type of magnesium sulfate called hexahydrite. A different type of magnesium sulfate is familiar on Earth as Epsom salt.
Nathues and colleagues, using images from Dawn's framing camera, suggest that these salt-rich areas were left behind when water-ice sublimated in the past. Impacts from asteroids would have unearthed the mixture of ice and salt, they say.
"The global nature of Ceres' bright spots suggests that this world has a subsurface layer that contains briny water-ice," Nathues said.
A New Look at Occator
The surface of Ceres, whose average diameter is 584 miles (940 kilometers), is generally dark -- similar in brightness to fresh asphalt -- study authors wrote. The bright patches that pepper the surface represent a large range of brightness, with the brightest areas reflecting about 50 percent of sunlight shining on the area. But there has not been unambiguous detection of water ice on Ceres; higher-resolution data are needed to settle this question.
The inner portion of a crater called Occator contains the brightest material on Ceres. Occator itself is 60 miles (90 kilometers) in diameter, and its central pit, covered by this bright material, measures about 6 miles (10 kilometers) wide and 0.3 miles (0.5 kilometers) deep. Dark streaks, possibly fractures, traverse the pit. Remnants of a central peak, which was up to 0.3 miles (0.5 kilometers) high, can also be seen.
With its sharp rim and walls, and abundant terraces and landslide deposits, Occator appears to be among the youngest features on Ceres. Dawn mission scientists estimate its age to be about 78 million years old.
Study authors write that some views of Occator appear to show a diffuse haze near the surface that fills the floor of the crater. This may be associated with observations of water vapor at Ceres by the Herschel space observatory that were reported in 2014. The haze seems to be present in views during noon, local time, and absent at dawn and dusk, study authors write. This suggests that the phenomenon resembles the activity at the surface of a comet, with water vapor lifting tiny particles of dust and residual ice. Future data and analysis may test this hypothesis and reveal clues about the process causing this activity.
"The Dawn science team is still discussing these results and analyzing data to better understand what is happening at Occator," said Chris Russell, principal investigator of the Dawn mission, based at the University of California, Los Angeles.
The Importance of Ammonia
In the second Nature study, members of the Dawn science team examined the composition of Ceres and found evidence for ammonia-rich clays. They used data from the visible and infrared mapping spectrometer, a device that looks at how various wavelengths of light are reflected by the surface, allowing minerals to be identified.
Ammonia ice by itself would evaporate on Ceres today, because the dwarf planet is too warm. However, ammonia molecules could be stable if present in combination with (i.e. chemically bonded to) other minerals.
The presence of ammoniated compounds raises the possibility that Ceres did not originate in the main asteroid belt between Mars and Jupiter, where it currently resides, but instead might have formed in the outer solar system. Another idea is that Ceres formed close to its present position, incorporating materials that drifted in from the outer solar system – near the orbit of Neptune, where nitrogen ices are thermally stable.
"The presence of ammonia-bearing species suggests that Ceres is composed of material accreted in an environment where ammonia and nitrogen were abundant. Consequently, we think that this material originated in the outer cold solar system,” said Maria Cristina De Sanctis, lead author of the study, based at the National Institute of Astrophysics, Rome.
In comparing the spectrum of reflected light from Ceres to meteorites, scientists found some similarities. Specifically, they focused on the spectra, or chemical fingerprints, of carbonaceous chondrites, a type of carbon-rich meteorite thought to be relevant analogues for the dwarf planet. But these are not good matches for all wavelengths that the instrument sampled, the team found. In particular, there were distinctive absorption bands, matching mixtures containing ammoniated minerals, associated with wavelengths that can't be observed from Earth-based telescopes.
The scientists note another difference is that these carbonaceous chondrites have bulk water contents of 15 to 20 percent, while Ceres' content is as much as 30 percent.
"Ceres may have retained more volatiles than these meteorites, or it could have accreted the water from volatile-rich material," De Sanctis said.
The study also shows that daytime surface temperatures on Ceres span from minus 136 degrees to minus 28 degrees Fahrenheit (180 to 240 Kelvin). The maximum temperatures were measured in the equatorial region. The temperatures at and near the equator are generally too high to support ice at the surface for a long time, study authors say, but data from Dawn's next orbit will reveal more details.
As of this week, Dawn has reached its final orbital altitude at Ceres, about 240 miles (385 kilometers) from the surface of the dwarf planet. In mid-December, Dawn will begin taking observations from this orbit, including images at a resolution of 120 feet (35 meters) per pixel, infrared, gamma ray and neutron spectra, and high-resolution gravity data.
Dawn's mission is managed by the Jet Propulsion Laboratory for NASA. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
Elizabeth Landau
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
[email protected]
2015-365
Last Updated: Dec. 9, 2015
Editor: Tony Greicius
http://www.nasa.gov/feature/jpl/dawn/new-clues-to-ceres-bright-spots-and-origins
Post by: clongton on 12/10/2015 01:13 pm
The good news is that all the science instruments aboard are functioning properly and we have a good solid year to extract a ton of observational data. I'm excited for this mission and really looking forward to the science.
Post by: yg1968 on 12/10/2015 11:49 pm
http://photojournal.jpl.nasa.gov/jpeg/PIA20182.jpg
Post by: yg1968 on 12/10/2015 11:51 pm
Post by: yg1968 on 12/10/2015 11:55 pm
http://www.planetary.org/blogs/emily-lakdawalla/2015/10221314-dawn-data-from-ceres-publicly.html
Post by: KelvinZero on 12/11/2015 09:15 am
Actually, I just noticed that there are color images of Ceres that have been released but NASA hasn't processed them yet.
http://www.planetary.org/blogs/emily-lakdawalla/2015/10221314-dawn-data-from-ceres-publicly.html
"So, without further ado: the first views of Ceres as they might look to your eyes, if you were riding aboard Dawn."
Finally ;)
So not much color. I may even have seen color images before and not realised it. I think I can just barely detect the blueish tints that are clearly visible in the ones where they have played with contrasts but it is not much more than the incorrect tints you sometimes get from bad jpg compression.
Post by: Star One on 12/11/2015 12:43 pm
Post by: Moe Grills on 12/11/2015 07:43 pm
Here's a new NASA article.
New Clues to Ceres' Bright Spots and OriginsQuoteCeres has more than 130 bright areas, and most of them are associated with impact craters. Study authors, led by Andreas Nathues at Max Planck Institute for Solar System Research, Göttingen, Germany, write that the bright material is consistent with a type of magnesium sulfate called hexahydrite. A different type of magnesium sulfate is familiar on Earth as Epsom salt.QuoteThere seems to be an enormous amount of Epsom Salts in our Solar System.Quote
The study also shows that daytime surface temperatures on Ceres span from minus 136 degrees to minus 28 degrees Fahrenheit (180 to 240 Kelvin).
Editor: Tony GreiciusQuote
minus 28 degrees F? That's temperatures in Alaska these days.Quote
http://www.nasa.gov/feature/jpl/dawn/new-clues-to-ceres-bright-spots-and-origins
Post by: Star One on 12/11/2015 08:05 pm
Here's a new NASA article.
New Clues to Ceres' Bright Spots and OriginsQuoteCeres has more than 130 bright areas, and most of them are associated with impact craters. Study authors, led by Andreas Nathues at Max Planck Institute for Solar System Research, Göttingen, Germany, write that the bright material is consistent with a type of magnesium sulfate called hexahydrite. A different type of magnesium sulfate is familiar on Earth as Epsom salt.QuoteThere seems to be an enormous amount of Epsom Salts in our Solar System.Quote
The study also shows that daytime surface temperatures on Ceres span from minus 136 degrees to minus 28 degrees Fahrenheit (180 to 240 Kelvin).
Editor: Tony GreiciusQuote
minus 28 degrees F? That's temperatures in Alaska these days.Quote
http://www.nasa.gov/feature/jpl/dawn/new-clues-to-ceres-bright-spots-and-origins
Ahem look up thread.
Post by: Star One on 12/22/2015 05:27 pm
Quote
NASA's Dawn spacecraft, cruising in its lowest and final orbit at dwarf planet Ceres, has delivered the first images from its best-ever viewpoint. The new images showcase details of the cratered and fractured surface. 3-D versions of two of these views are also available.
http://www.sciencedaily.com/releases/2015/12/151222113853.htm
Quote
The online Slooh Community Observatory will host a live webcast today (Dec. 22) at 2 p.m.. EST (1900 GMT) featuring new images of the dwarf planet Ceres. You can go to Slooh.com to join and watch this broadcast live; the show will also appear in the window below.
http://m.space.com/19195-night-sky-planets-asteroids-webcasts.html
Post by: Star One on 12/22/2015 10:47 pm
http://dawn.jpl.nasa.gov/multimedia/images/
Post by: Star One on 12/26/2015 08:11 pm
Quote
Dawn
This image of Ceres was taken in Dawn's low-altitude mapping orbit around a crater chain called Gerber Catena. A 3-D view is also available. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
› Full image and caption
NASA's Dawn spacecraft, cruising in its lowest and final orbit at dwarf planet Ceres, has delivered the first images from its best-ever viewpoint. The new images showcase details of the cratered and fractured surface. 3-D versions of two of these views are also available.
Dawn took these images of the southern hemisphere of Ceres on Dec. 10, at an approximate altitude of 240 miles (385 kilometers), which is its lowest-ever orbital altitude. Dawn will remain at this altitude for the rest of its mission, and indefinitely afterward. The resolution of the new images is about 120 feet (35 meters) per pixel.
Among the striking views is a chain of craters called Gerber Catena, located just west of the large crater Urvara. Troughs are common on larger planetary bodies, caused by contraction, impact stresses and the loading of the crust by large mountains -- Olympus Mons on Mars is one example. The fracturing found all across Ceres' surface indicates that similar processes may have occurred there, despite its smaller size (the average diameter of Ceres is 584 miles, or 940 kilometers). Many of the troughs and grooves on Ceres were likely formed as a result of impacts, but some appear to be tectonic, reflecting internal stresses that broke the crust.
"Why they are so prominent is not yet understood, but they are probably related to the complex crustal structure of Ceres," said Paul Schenk, a Dawn science team member at the Lunar and Planetary Institute, Houston.
The images were taken as part of a test of Dawn's backup framing camera. The primary framing camera, which is essentially identical, began its imaging campaign at this lowest orbit on Dec. 16. Both cameras are healthy.
Dawn's other instruments also began their intense period of observations this month. The visible and infrared mapping spectrometer will help identify minerals by looking at how various wavelengths of light are reflected by the surface of Ceres. The gamma ray and neutron detector is also active. By measuring the energies and numbers of gamma rays and neutrons, two components of nuclear radiation, it will help scientists determine the abundances of some elements on Ceres.
Earlier in December, Dawn science team members revealed that the bright material found in such notable craters as Occator is consistent with salt -- and proposed that a type of magnesium sulfate called hexahydrite may be present. A different group of Dawn scientists found that Ceres also contains ammoniated clays. Because ammonia is abundant in the outer solar system, this finding suggests that Ceres could have formed in the vicinity of Neptune and migrated inward, or formed in place with material that migrated in from the outer solar system.
"As we take the highest-resolution data ever from Ceres, we will continue to examine our hypotheses and uncover even more surprises about this mysterious world," said Chris Russell, principal investigator of the Dawn mission, based at the University of California, Los Angeles.
Dawn is the first mission to visit a dwarf planet, and the first mission outside the Earth-moon system to orbit two distinct solar system targets. It orbited protoplanet Vesta for 14 months in 2011 and 2012, and arrived at Ceres on March 6, 2015.
Dawn's mission is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
http://dawn.jpl.nasa.gov/news/news-detail.html?id=4802
Post by: clongton on 12/27/2015 09:29 pm
Post by: Star One on 12/28/2015 09:57 am
Post by: Star One on 01/13/2016 05:43 pm
But mysteries still remain.
http://gizmodo.com/theres-something-surprising-lurking-in-ceres-mysterious-1752480994
Post by: corrodedNut on 01/29/2016 05:35 pm
"Published on Jan 29, 2016 - Take a flight over dwarf planet Ceres in this video made with images from NASA's Dawn spacecraft. The simulated flyover was made by the mission's camera team at Germany's national aeronautics and space research center (DLR)."
Post by: meekGee on 01/29/2016 10:49 pm
Post by: Chris Bergin on 03/06/2016 12:53 pm
Feature article by Chris Gebhardt.
Post by: Lar on 03/06/2016 01:19 pm
Remember people, use the share button to get good NSF content in front of your friends. NSF needs more readers (and not just during high traffic times) :)
Post by: ChrisGebhardt on 03/06/2016 04:15 pm
Great write up.
Remember people, use the share button to get good NSF content in front of your friends. NSF needs more readers (and not just during high traffic times) :)
What a wonderful opportunity to plug our Facebook page. Head on over, "like" our page, and share our articles.
https://www.facebook.com/NASASpaceflight/
Post by: Star One on 03/12/2016 06:54 pm
Quote
We’re still waiting for close-up shots of Occator crater with its bizarre bright spots in it, but in the meantime there’s no lack of weirdness coming from Ceres. The shot above shows Ahuna Mons, a mountain on Ceres 5 kilometers high and 20 kilometers long.
http://www.slate.com/blogs/bad_astronomy/2016/03/12/ahuna_mons_a_mountain_on_ceres.html
Post by: Zed_Noir on 03/12/2016 09:27 pm
Why Is There a Huge Mountain on Ceres?QuoteWe’re still waiting for close-up shots of Occator crater with its bizarre bright spots in it, but in the meantime there’s no lack of weirdness coming from Ceres. The shot above shows Ahuna Mons, a mountain on Ceres 5 kilometers high and 20 kilometers long.
http://www.slate.com/blogs/bad_astronomy/2016/03/12/ahuna_mons_a_mountain_on_ceres.html
AKA The Lonely Mountain :)
Post by: Star One on 03/16/2016 08:45 pm
Unexpected Changes of Bright Spots on Ceres Discovered
Quote
Observations made using the HARPS spectrograph at ESO’s La Silla Observatory in Chile have revealed unexpected changes in the bright spots on the dwarf planet Ceres. Although Ceres appears as little more than a point of light from the Earth, very careful study of its light shows not only the changes expected as Ceres rotates, but also that the spots brighten during the day and also show other variations. These observations suggest that the material of the spots is volatile and evaporates in the warm glow of sunlight.
Quote
The team concluded that the observed changes could be due to the presence of volatile substances that evaporate under the action of solar radiation [2]. When the spots inside the Occator crater are on the side illuminated by the Sun they form plumes that reflect sunlight very effectively. These plumes then evaporate quickly, lose reflectivity and produce the observed changes. This effect, however, changes from night to night, giving rise to additional random patterns, on both short and longer timescales.
https://www.eso.org/public/news/eso1609/#1
Post by: NovaSilisko on 03/22/2016 04:37 pm
In all its majesty, Occator crater...
Post by: NovaSilisko on 03/22/2016 04:38 pm
The windblown terrain is intruiging me the most. There are subtle streaks leading away from Occator all over the image.
Ceres, what are you?
Post by: alk3997 on 03/22/2016 05:01 pm
Andy
Post by: MattMason on 03/22/2016 05:07 pm
http://www.nasa.gov/feature/jpl/bright-spots-and-color-differences-revealed-on-ceres
In all its majesty, Occator crater...
And with that, the Cervidan Space Agency is born. Ut sales ad astra.
That's one beautifully large celestial salt lick. We're at closest orbit here, right?
I don't see how any other conclusion could be made for a high concentration of salts.
Post by: ugordan on 03/22/2016 05:10 pm
Post by: Ben the Space Brit on 03/22/2016 09:13 pm
Post by: Star One on 03/23/2016 09:00 am
Quote
Just how this arrangement formed is still a mystery. Timothy Bowling of the University of Chicago presented a model of a possible explanation, in which a meteorite smacks into the surface of Ceres, exposing icy material from as much as 40 kilometres below the surface and heating it up. “Occator is probing deep into Ceres sub-surface,” he said. As this material settled into the Occator crater we see today, the water would evaporate, leaving bright salt and minerals behind.
Quote
Dawn will continue to gather data about Ceres until at least August, and possibly into next year, depending on the health of its reaction wheels, which are used to control its orientation. But some questions about this enigmatic asteroid may not be answered until a repeat visit. “It would be nice to land there, wouldn’t it?” said Raymond.
https://www.newscientist.com/article/2082050-ceres-surprises-with-water-ice-and-colourful-bright-spots/
Post by: yg1968 on 03/24/2016 04:37 pm
http://www.universetoday.com/128013/finally-ceres-white-spots-close/
Post by: yg1968 on 03/24/2016 04:48 pm
https://www.youtube.com/watch?v=2_-2eQgFZuc
Post by: David Palmer on 03/28/2016 07:26 am
Evidently the impact that created Occator Crater punched through into a subsurface ocean of Ceres, and created a weak spot that has henceforth served as a conduit for cryovolcanic outflows.
The main bright spot is inside of what appears to be a volcanic caldera, a depressed area with concentric cracks around (and inside) its perimeter, evidently produced through the collapse of the roof of a "magma" chamber after its contents were disgorged. And in the center of the caldera we have more recent dome-building (i.e., analogous to a terrestrial lava dome that forms after a previous eruption), where slush has apparently pushed up (possibly in preparation for another significant eruption in the future), and this has caused radial cracks in the center (on the slopes of the dome) where the crust has been stretched.
This is extremely similar to the processes and landforms characterizing terrestrial volcanism, the only difference being that water is the "magma" in this case.
And just as with terrestrial volcanoes, we have outlying "cinder cones," apparently associated with fractures pointing radially away from the central caldera (to the right of caldera/main vent in photo).
While it might be suggested that the bright deposits involved with these features (tentatively identified as hydrated magnesium sulfate, i.e. the dessicated remains of outflowing brine) are simply a relic of ancient hydrothermal activity spawned by the heat of the original impact (approx. 80 million years ago on the basis of crater counts), the fact that the material is still bright, and not darkened by cosmic radiation and meteoric dust over tens of millions of years, indicates that much of the cryovolcanic activity has been far more recent than the formation of Occator Crater. Plus the observations of apparent vapor or fog above the floor of Occator Crater, in a diurnal cycle, indicate the same. Because unless there were geologically recent (or even currently-ongoing) outflows, any such volatiles would have sublimed away to nothing long ago.
The idea that Ceres still has a subsurface ocean has certainly not been universally accepted, apparently because thermodynamic models suggest that such a relatively small body would have frozen long ago. But this is operating under the assumption that the liquid water is very nearly pure, whereas in practice it is likely to have a number of dissolved antifreeze compounds (salts such as magnesium sulfate, as well as ammonia, the latter of which is indicated by the presence of ammonia-rich clays in the vicinity of the bright spots). And an ammonia and salt-saturated brine would have a freezing point as low as minus 100 degrees Celsius, which is just a few degrees above the average global surface temperature of Ceres (estimated at minus 105 Celsius). So it wouldn't take much of an internal heat source to keep such a subsurface ocean liquid since the formation of Ceres.
The processes occurring here are somewhat similar to what I have suggested in my "artesian hydrant" model for the otherwise-inexplicable geology of Mars' Mt. Sharp. Namely that there are conduits connecting the surface of Mt. Sharp to an underground aquifer, and which are still occasionally active, and which I deem necessary to explain the relative youth of the channel and delta deposit to which Curiosity is currently headed (an aqueous-derived landform that has a relative lack of both cratering and erosional damage, and thus must be no more than approx. 100 million years old, and possibly considerably less).
I would predict that Ceres will become an extremely hot target for exobiological research, with a huge push for a sample-return from Occator Crater, as any recent outflows might contain not only fossil organisms, but possible viable ones that could be revived, if an outflow were sufficiently fresh. And given the relatively small mass of Ceres, landing on it and taking off would be relatively easy with existing technology (its mass is only about 1/700 that of Mars and 1/90 that of Earth's moon).
It has been speculated that life on Earth may have originally come from Ceres, as such a small body would have cooled down to the point of supporting liquid water long before Earth (or even Mars) did so. And because of its location and low escape velocity, Ceres could be expected to have undergone numerous impacts that splattered (possibly life-bearing) material towards the inner solar system. So if microbes were to be found, an analysis of their genetics might actually reveal them to be our distant ancestors!
David Palmer
Post by: Star One on 03/28/2016 08:21 am
Post by: David Palmer on 03/28/2016 09:35 am
Post by: Star One on 03/28/2016 01:27 pm
I wasn't quoting anybody, I was just continuing the thread with my interpretation of Ceres.
It looked like you were quoting someone. But if you weren't then apologies.
Post by: yg1968 on 03/31/2016 12:31 am
http://www.planetary.org/blogs/emily-lakdawalla/2016/0330-lpsc-2016-so-much-ceres.html?referrer=https://t.co/5Dgnfv7Pwz
Post by: David Palmer on 03/31/2016 09:03 am
As far as the origin of the mysterious pyramid-shaped mountain (Ahuna Mons), I find it to be a bit too much of a coincidence that there is a relatively young crater of approximately the same size right next-door, and can't help but suspect that there is a connection. And I would like to suggest the following model: as the largely-water-ice crust of Ceres has continued to thicken over time (due to the internal heat source gradually running down), cracking of the crust has occurred, some of which would be polygonal in shape, and I would suggest that the crater-creating impact occurred right next to one such polygonal section, and the resultant pressure impulse in the subsurface ocean (slightly) popped that section up through the surrounding crust. And since that time, continued freezing in the subsurface ocean has pushed the polygonal section further upwards, in response to the vertical force created by expansion of the freezing water below, and due to the fact that the cracks defining its edges (cracks which became vertical faults) de-coupled it from the surrounding crust and allowed it to move fairly independently of that crust. So this mountain is basically what is referred to as a "horst" in Earth geology, but because of the differences in crustal composition and dynamics here, there are no surrounding "grabens," and Ahuna Mons doesn't take the shape of the linear ridge that is typical of terrestrial horsts..
Post by: Star One on 03/31/2016 01:51 pm
Actually, I find Emily's analysis to be a bit too conservative and limited, not drawing out the full implications of the geology that we're seeing on Ceres. She says that the dome in Occator was evidently created by material pushing up from below, and quotes a scientist involved in the mission as saying that the activity looks to be geologically recent, but she doesn't draw out the obvious implication for the presence of a subsurface ocean.
As far as the origin of the mysterious pyramid-shaped mountain (Ahuna Mons), I find it to be a bit too much of a coincidence that there is a relatively young crater of approximately the same size right next-door, and can't help but suspect that there is a connection. And I would like to suggest the following model: as the largely-water-ice crust of Ceres has continued to thicken over time (due to the internal heat source gradually running down), cracking of the crust has occurred, some of which would be polygonal in shape, and I would suggest that the crater-creating impact occurred right next to one such polygonal section, and the resultant pressure impulse in the subsurface ocean (slightly) popped that section up through the surrounding crust. And since that time, continued freezing in the subsurface ocean has pushed the polygonal section further upwards, in response to vertical pressure created by expansion of the freezing water below, and due to the fact that the cracks defining its edges (cracks which became vertical faults) de-coupled it from the surrounding crust and allowed it to move fairly independently of that crust. So this mountain is basically what is referred to as a "horst" in Earth geology, but because of the differences in crustal composition and dynamics here, there are no surrounding "grabens," and Ahuna Mons doesn't take the shape of the linear ridge that is typical of terrestrial horsts..
I am not sure how much any ocean would actually be cooling down being as unlike Pluto Ceres must still be hit by a fair degree of sunlight being comparatively much closer to the Sun, and as the Sun heats up over time this will continue to increase.
Post by: yg1968 on 03/31/2016 02:30 pm
Actually, I find Emily's analysis to be a bit too conservative and limited, not drawing out the full implications of the geology that we're seeing on Ceres. She says that the dome in Occator was evidently created by material pushing up from below, and quotes a scientist involved in the mission as saying that the activity looks to be geologically recent, but she doesn't draw out the obvious implication for the presence of a subsurface ocean.
During the press conference, I believe that they said that there may have been a subsurface ocean at some point in Ceres' past but they don't believe that there is one anymore.
Post by: David Palmer on 04/01/2016 10:44 am
During the press conference, I believe that they said that there may have been a subsurface ocean at some point in Ceres' past but they don't believe that there is one anymore.
They did indeed say that, but it's not in keeping with the "ground evidence": the cryovolcanism in at least Occator is only explicable in the context of a subsurface ocean, as it is obviously much more recent that the crater's formation (based on its brightness and continuing evolution of volatiles). Plus realistic thermodynamic and hydrodynamic models indicate that a subsurface ocean should be present. Because we can expect any subsurface ocean to be briny, based on the chemistry of the surface....plus the fact that when a salt-containing ocean freezes, the pure water component will preferentially freeze, leaving the remainder more and more resistant to freezing over time. And a concentrated brine would have a freezing point only a few degrees above the average surface temperature of Ceres. So with an insulating crust and ANY significant internal heat source, we may expect a subsurface ocean to still be present (although the "cryosphere" of the crust/upper mantle has no doubt grown thicker and thicker over time).
Post by: the_other_Doug on 04/01/2016 06:12 pm
During the press conference, I believe that they said that there may have been a subsurface ocean at some point in Ceres' past but they don't believe that there is one anymore.
They did indeed say that, but it's not in keeping with the "ground evidence": the cryovolcanism in at least Occator is only explicable in the context of a subsurface ocean, as it is obviously much more recent that the crater's formation (based on its brightness and continuing evolution of volatiles). Plus realistic thermodynamic and hydrodynamic models indicate that a subsurface ocean should be present. Because we can expect any subsurface ocean to be briny, based on the chemistry of the surface....plus the fact that when a salt-containing ocean freezes, the pure water component will preferentially freeze, leaving the remainder more and more resistant to freezing over time. And a concentrated brine would have a freezing point only a few degrees above the average surface temperature of Ceres. So with an insulating crust and ANY significant internal heat source, we may expect a subsurface ocean to still be present (although the "cryosphere" of the crust/upper mantle has no doubt grown thicker and thicker over time).
The Dawn team seems to believe that any subsurface ocean must have completely frozen eons ago. I think that, in some cases, we could be looking at remnant pockets of liquid brine, but perhaps these are all that is left of a once-liquid ocean.
I'm not a planetary geologist, although it is a hobby... but I think we need more information before we can declare the issue settled either way. AIUI, most models seem to predict no liquid ocean, is I guess all I wanted to say.
Post by: Don2 on 04/01/2016 09:11 pm
Liquids are not possible at the surface due to a lack of pressure. If liquid erupts on to the surface then it will produce a two phase mixture of vapor and ice crystals which may well behave like a cold pyroclastic flow. This could explain some of the features seen in the Occator region.
Post by: David Palmer on 04/02/2016 12:29 am
I'm not sure that people understand the implications of the detection of ammoniated clays at Ceres. Ammonia drops the freezing point of water by up to 90 Celsius. It is extremely soluble, so ammonia in the crust of Ceres is likely to concentrate in the ocean. A 35% solution of ammonia in water is liquid down to 182K, which is significantly colder than the warmer parts of the surface. Surface temperatures of up to 235K have been measured. No internal heat source is required for subsurface liquids.
EXACTLY! So I don't know why the NASA folks think that any subsurface ocean would have frozen long ago. Between these theoretical considerations involving ammonia and salt solutions, and the density of Ceres showing that it's largely composed of water/water ice, and the surface evidence of recent cryovolcanism, it seems to me that the presence of a subsurface ocean would be a slam-dunk.
BUT, John Grotzinger (the former science head for Curiosity) was giving some very implausible interpretations of the geology of Gale Crater (which is a whole 'nother subject, which I have previously written about), so maybe I shouldn't be surprised.
Post by: Star One on 04/07/2016 06:47 pm
Quote
Russell said the Dawn mission could receive funding for a few extra months without going through a peer review by a panel of independent scientists — called a senior review — if the extension is short-term and does not involve any major change in flight plan.
The senior review held every two years helps NASA determine which of its operating space missions deserve extensions, and which projects have diminishing returns.
http://spaceflightnow.com/2016/04/06/dawn-mission-expected-to-go-into-overtime-at-ceres/
Post by: Ben the Space Brit on 04/08/2016 12:18 pm
Post by: catdlr on 04/19/2016 07:14 pm
By: SciNews
Published on Apr 19, 2016
Craters on Ceres seen by NASA’s Dawn mission from its lowest-altitude mapping orbit, 385 kilometers (240 miles) from Ceres:
- Occator Crater and Ceres' Brightest Spots
- Region north of Urvara Crater
- Haulani Crater with a diameter of 34 kilometers (21 miles)
- Oxo Crater 10-kilometer-wide(6-mile-wide)
- Dada Crater & Roskva Crater
- unnamed craters in the northern hemisphere of Ceres
- impact crater at high southern latitude
- fresh crater among older terrain
Images credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
https://youtu.be/uqAUPBXBbxs
Post by: Ben the Space Brit on 04/20/2016 11:51 am
Post by: vjkane on 04/20/2016 09:19 pm
https://www.newscientist.com/article/2085288-nasas-dawn-probe-may-visit-third-asteroid-after-ceres-and-vesta/
Post by: Star One on 04/20/2016 09:24 pm
New Scientist just posted a short piece stating that there's a mission extension proposal to fly away from Ceres and possibly go to a new asteroid. I'm skeptical given that everything printed in the last few months talks about continuing orbital observations until the fuel is exhausted by late or early next year. Has anyone else heard anything about this?I can't see how they could do this considering the issues they had getting Dawn into its last and lowest orbit.
https://www.newscientist.com/article/2085288-nasas-dawn-probe-may-visit-third-asteroid-after-ceres-and-vesta/
Post by: NovaSilisko on 04/20/2016 09:25 pm
Quote
“The spacecraft has not been sterilised, so we aren’t allowed to touch down on the surface of Ceres,” says Russell.
Not to mention the fact it has nowhere near the thrust-to-weight ratio to land...? Neither thrusters nor ion drive can land it. The thrusters wouldn't have enough delta-v anyway.
Post by: as58 on 04/20/2016 10:00 pm
https://ac.arc.nasa.gov/p6693vwn85n/?launcher=false&fcsContent=true&pbMode=normal
Also SBAG slides from last month's NAC Planetary Science Subcommittee seem to mention only mission extension at Ceres:
http://science.nasa.gov/media/medialibrary/2016/03/15/SBAG_PSS_March2016.pptx.pdf
On the other hand, New Scientist article includes direct quotes from the PI, so there doesn't seem to be much chance of misunderstanding either.
Post by: whitelancer64 on 04/20/2016 10:14 pm
Very strange. Carol Raymond mentions mission extension in her presentation at the latest SBAG meeting at the end of January, but there's nothing to indicate that they're planning anything other than further studies at Ceres.
https://ac.arc.nasa.gov/p6693vwn85n/?launcher=false&fcsContent=true&pbMode=normal
Also SBAG slides from last month's NAC Planetary Science Subcommittee seem to mention only mission extension at Ceres:
http://science.nasa.gov/media/medialibrary/2016/03/15/SBAG_PSS_March2016.pptx.pdf
On the other hand, New Scientist article includes direct quotes from the PI, so there doesn't seem to be much chance of misunderstanding either.
That's not strange at all -- Dawn no longer has enough fuel to break orbit from Ceres.
Post by: NovaSilisko on 04/20/2016 10:16 pm
Very strange. Carol Raymond mentions mission extension in her presentation at the latest SBAG meeting at the end of January, but there's nothing to indicate that they're planning anything other than further studies at Ceres.
https://ac.arc.nasa.gov/p6693vwn85n/?launcher=false&fcsContent=true&pbMode=normal
Also SBAG slides from last month's NAC Planetary Science Subcommittee seem to mention only mission extension at Ceres:
http://science.nasa.gov/media/medialibrary/2016/03/15/SBAG_PSS_March2016.pptx.pdf
On the other hand, New Scientist article includes direct quotes from the PI, so there doesn't seem to be much chance of misunderstanding either.
That's not strange at all -- Dawn no longer has enough fuel to break orbit from Ceres.
as58 was saying the New Scientist report and the comments from the PI were strange, because it's contradicted by that very fact.
Post by: as58 on 04/20/2016 10:24 pm
And yes, I meant that the New Scientist report is strange, because if it's true Dawn mission people have made a complete change of plans very recently.
Edit: actually Carol Raymond says in her presentation that they have xenon left.
Post by: whitelancer64 on 04/20/2016 10:40 pm
But it seems the Dawn team thinks otherwise.
Post by: NovaSilisko on 04/20/2016 10:45 pm
Post by: the_other_Doug on 04/20/2016 11:08 pm
I know that Dawn is not going to enter a lower science orbit than where it is now because of the low amount of maneuvering fuel and degraded control-gyro capability. It's not that they are concerned about landing Dawn on Ceres -- I don't recall that this was ever planned, anyway. It's that they can't get into an orbit where, without maneuvering, it could crash into Ceres over the next several decades. And since Dawn isn't sterilized, they don't want it to crash into Ceres, either.
AIUI, this means this LAMO (Low Altitude Mapping Orbit) they're in now is the lowest orbit they will attempt, and that at the end of extended mission, they may even go into a higher disposal orbit, maximizing the time it will take before Dawn could ever naturally impact Ceres.
But I know I've not heard of any viable extended mission plans that involve leaving Ceres. When they arrived, the Dawn team basically stated that they wouldn't ever be leaving.
Post by: as58 on 04/20/2016 11:14 pm
I think New Scientist may have misinterpreted something about the extended mission concepts.
It's hard to see how there could be a misunderstanding when there's a direct quote from the PI:
Quote
“Instead, we want to go the other way, away from Ceres, to visit yet another target.”
Post by: whitelancer64 on 04/20/2016 11:16 pm
But the baseline since ~2005 has always been to remain in Ceres orbit at the end of the mission.
So it won't be Pallas, but there are plenty of main-belt asteroids to choose from.
Post by: Star One on 04/21/2016 08:13 am
Post by: eeergo on 04/21/2016 09:02 am
It's that they can't get into an orbit where, without maneuvering, it could crash into Ceres over the next several decades. And since Dawn isn't sterilized, they don't want it to crash into Ceres, either.
AIUI, this means this LAMO (Low Altitude Mapping Orbit) they're in now is the lowest orbit they will attempt, and that at the end of extended mission, they may even go into a higher disposal orbit, maximizing the time it will take before Dawn could ever naturally impact Ceres.
LAMO is much more stable than that, I've seen estimates of thousands of years. Perturbations are very weak, and only due to the other planets. Unless they have discovered an extremely strong mascon-like feature, the Cerean gravitational field is quite homogeneous and won't cause large orbital upsets.
Post by: Ben the Space Brit on 04/22/2016 08:59 am
Post by: mcgyver on 04/22/2016 04:44 pm
it can't land because not sterilized,
can't leave due to lack of fuel,
... but it can't even stay in orbit for ever, as it will eventually collapse to Ceres anyway!
Or not?!? ???
Post by: CuddlyRocket on 04/23/2016 02:56 am
Purely hypothetically, could Jupiter's gravity affect Dawn enough to eventually drag it into a higher or lower orbit (or even eject it entirely from Ceresian orbit)?
I calculate Ceres' Hill sphere with respect to Jupiter at closest approach to be just shy of 2 million kilometres, which suggests not as Dawn is orbiting well inside that distance.
Post by: redliox on 06/07/2016 11:57 am
Post by: Ben the Space Brit on 06/07/2016 12:21 pm
Post by: as58 on 06/07/2016 01:23 pm
There was talk a mission extension, possibly to even a new body, is being looked into for Dawn. Can anyone confirm this? The only specific information was that in August or September the team is going to announce ideas for mission extensions.
I have no new info, but NAC Planetary Science Subcommittee has a meeting today. Maybe something will be said there.
http://science.nasa.gov/science-committee/subcommittees/nac-planetary-science-subcommittee/
Post by: Alpha_Centauri on 06/07/2016 01:30 pm
The mission extension (I think it was to 3 Juno) was ruled out due to the failure of some of the spacecraft's reaction wheels. There isn't enough RCS propellent to maintain stability long enough for the transfer or for a worthwhile number of science orbits at the target body.That was the case but the fuel situation is better than was anticipated, I believe Redilox is referring to the new plan for a mission extension apparently being drawn up;
https://www.newscientist.com/article/2085288-nasas-dawn-probe-may-visit-third-asteroid-after-ceres-and-vesta/
There may be more on this in an upcoming Dawn Journal entry.
Post by: redliox on 06/07/2016 02:33 pm
The mission extension (I think it was to 3 Juno) was ruled out due to the failure of some of the spacecraft's reaction wheels. There isn't enough RCS propellent to maintain stability long enough for the transfer or for a worthwhile number of science orbits at the target body.That was the case but the fuel situation is better than was anticipated, I believe Redilox is referring to the new plan for a mission extension apparently being drawn up;
https://www.newscientist.com/article/2085288-nasas-dawn-probe-may-visit-third-asteroid-after-ceres-and-vesta/
There may be more on this in an upcoming Dawn Journal entry.
Pretty much. I saw an article from space.com talking about it, but they were brief.
I'm well aware Dawn has busted gyroscopes and minimal hydrazine left, so the odds of flying off to a new target are not ideal if abysmal. THAT is why I thought to refresh the news here to get confirmation.
Post by: Bynaus on 06/07/2016 02:44 pm
Post by: Sam Ho on 06/07/2016 03:06 pm
Quote
Without three of these units to control its orientation in space, the robot has relied on its limited supply of hydrazine, which was not intended to serve this function. But the mission’s careful stewardship of the precious propellant has continued to exceed even the optimistic predictions, allowing Dawn good prospects for carrying on its fruitful work. In an upcoming Dawn Journal, we will discuss how the last of the dwindling supply of hydrazine may be used for further discoveries.The April Dawn Journal said that RCS hydrazine consumption was coming in better than expected, partly because the two remaining reaction wheels have stayed alive throughout the LAMO, so they submitted a proposal for an extended mission.
http://dawnblog.jpl.nasa.gov/2016/04/29/dawn-journal-april-29-2/
Quote
As responsible citizens of the solar system, NASA conforms to “planetary protection” protocols which specify that Dawn may not reach the surface for at least 50 years after arrival. (The reasoning behind the limited duration is that if our data indicate that Ceres really does need special protection, half a century would be long enough to mount another mission if need be.) Extensive analyses by engineers and scientists show that for any credible detail of the dwarf planet’s gravitational field, the orbit will remain relatively stable for much longer than that, perhaps even millennia. The ship will not make landfall.The August 2014 Dawn Journal also mentioned the planetary protection requirement that there be no impact for at least 50 years. LAMO is quite stable and meets this requirement, but they will not be going lower.
http://dawnblog.jpl.nasa.gov/2014/08/31/dawn-journal-august-31/#fate
Quote from: Marc Rayman: 05/04/2016 05:42 CDT
In 2014, the thought was that an extended mission would continue in LAMO until the hydrazine runs out, but the mission team has been dropping hints that they now have another target in mind, as seen in this comment from the April Dawn Journal.Quote from: ToSeek: 05/04/2016 04:18 CDTThere's been talk of Dawn leaving Ceres and heading for yet another target. Any comment on that? (Thanks for all the great updates, regardless.)
Thank you, ToSeek. It is too premature to comment on that.
I will mention, however, that I've seen comments on this website and elsewhere about the possibility of Dawn going to Pallas. I've pointed out in answer to such comments that that rumor was never well founded. The Dawn flight team has never conducted studies of going to Pallas.
http://www.planetary.org/blogs/guest-blogs/marc-rayman/0504-dawn-journal-a-new-angle-on-ceres.html
Post by: the_other_Doug on 06/07/2016 07:50 pm
Post by: Star One on 06/07/2016 08:05 pm
Quote
This ‘diffuse haze,’ as the authors describe it, fills the floor of Occator and then disappears almost completely at dusk, providing a possible counterpart to the radial velocity variability that Molaro and team have detected. That’s useful, because if both are produced by the same cause, then we have a way to continue to monitor daily activity on Ceres even after the Dawn mission ends. Further radial velocity observations and analysis of the Dawn imagery could confirm this possibility.
http://www.centauri-dreams.org/?p=35774
Post by: Ben the Space Brit on 06/08/2016 11:11 am
There is a cluster of small-ish asteroids in the same area as Ceres that seem to be the disrupted remains of a single body. One suggestion that I've seen for Dawn's extended mission is to fly by a few of these objects and get imagery and spectrographic readings to see if they look like fragments of a single parent object.
Post by: Star One on 06/29/2016 08:06 pm
The brightest area on Ceres, located in the mysterious Occator Crater, has the highest concentration of carbonate minerals ever seen outside Earth, according to a new study from scientists on NASA's Dawn mission. The study, published online in the journal Nature, is one of two new papers about the makeup of Ceres.
"This is the first time we see this kind of material elsewhere in the solar system in such a large amount," said Maria Cristina De Sanctis, lead author and principal investigator of Dawn's visible and infrared mapping spectrometer. De Sanctis is based at the National Institute of Astrophysics, Rome.
At about 80 million years old, Occator is considered a young crater. It is 57 miles (92 kilometers) wide, with a central pit about 6 miles (10 kilometers) wide. A dome structure at the center, covered in highly reflective material, has radial and concentric fractures on and around it.
De Sanctis' study finds that the dominant mineral of this bright area is sodium carbonate, a kind of salt found on Earth in hydrothermal environments. This material appears to have come from inside Ceres, because an impacting asteroid could not have delivered it. The upwelling of this material suggests that temperatures inside Ceres are warmer than previously believed. Impact of an asteroid on Ceres may have helped bring this material up from below, but researchers think an internal process played a role as well.
More intriguingly, the results suggest that liquid water may have existed beneath the surface of Ceres in recent geological time. The salts could be remnants of an ocean, or localized bodies of water, that reached the surface and then froze millions of years ago.
"The minerals we have found at the Occator central bright area require alteration by water," De Sanctis said. "Carbonates support the idea that Ceres had interior hydrothermal activity, which pushed these materials to the surface within Occator."
The spacecraft's visible and infrared mapping spectrometer examines how various wavelengths of sunlight are reflected by the surface of Ceres. This allows scientists to identify minerals that are likely producing those signals. The new results come from the infrared mapping component, which examines Ceres in wavelengths of light too long for the eye to see.
Last year, in a Nature study, De Sanctis' team reported that the surface of Ceres contains ammoniated phyllosilicates, or clays containing ammonia. Because ammonia is abundant in the outer solar system, this finding introduced the idea that Ceres may have formed near the orbit of Neptune and migrated inward. Alternatively, Ceres may have formed closer to its current position between Mars and Jupiter, but with material accumulated from the outer solar system.
The new results also find ammonia-bearing salts -- ammonium chloride and/or ammonium bicarbonate -- in Occator Crater. The carbonate finding further reinforces Ceres' connection with icy worlds in the outer solar system. Ammonia, in addition to sodium carbonate and sodium bicarbonate found at Occator, has been detected in the plumes of Enceladus, an icy moon of Saturn known for its geysers erupting from fissures in its surface. Such materials make Ceres interesting for the study of astrobiology.
"We will need to research whether Ceres' many other bright areas also contain these carbonates," De Sanctis said.
A separate Nature study in 2015 by scientists with the Dawn framing camera team hypothesized that the bright areas contain a different kind of salt: magnesium sulfate. But the new findings suggest sodium carbonate is the more likely constituent.
"It's amazing how much we have been able to learn about Ceres' interior from Dawn's observations of chemical and geophysical properties. We expect more such discoveries as we mine this treasure trove of data," said Carol Raymond, deputy principal investigator for the Dawn mission, based at NASA's Jet Propulsion Laboratory, Pasadena, California.
Dawn science team members have also published a new study about the makeup of the outer layer of Ceres in Nature Geoscience, based on images from Dawn's framing camera. This study, led by Michael Bland of the U.S. Geological Survey, Flagstaff, Arizona, finds that most of Ceres' largest craters are more than 1 mile (2 kilometers) deep relative to surrounding terrain, meaning they have not deformed much over billions of years. These significant depths suggest that Ceres' subsurface is no more than 40 percent ice by volume, and the rest may be a mixture of rock and low-density materials such as salts or chemical compounds called clathrates. The appearance of a few shallow craters suggests that there could be variations in ice and rock content in the subsurface.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
News Media Contact
Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
[email protected]
http://www.jpl.nasa.gov/news/news.php?feature=6547
Post by: MattMason on 06/29/2016 08:13 pm
Post by: Star One on 06/29/2016 08:34 pm
Green: planetary science senior review decisions due late this week or early next; in time for Dawn to decide to leave Ceres or not. #SBAG
Post by: rpapo on 06/29/2016 08:43 pm
Didn't someone nail this prediction at the start of this thread? More cryo-geysers? Or is this phenomenon of a different variation and cause than Europa or that-Saturn-moon-I-can't-spell-that-begins-with-E?Enceladus (Enchiladas for the Latin impaired...)
Post by: jacqmans on 06/30/2016 06:10 pm
Orbital ATK-Designed and -Built Spacecraft Advanced Understanding of Planetary Formation in the Solar System
Dawn Project Team Received Prestigious Awards for Historic Mission
Dulles, Virginia 30 June 2016 – Orbital ATK, Inc. (NYSE: OA), a global leader in aerospace and defense technologies, today celebrates the achievements of NASA’s Dawn deep space exploration spacecraft as it successfully completes its primary mission. Designed and built by Orbital ATK, Dawn is in the ninth year of its historic journey, which is advancing human understanding of planetary formation and revealing new mysteries of the solar system.
“Dawn’s successful, interplanetary mission is a testament to the ingenuity and dedication of the entire JPL-led mission team and NASA,” said Frank Culbertson, President of Orbital ATK’s Space Systems Group. “Orbital ATK designed and built Dawn more than 10 years ago, relying on our flight-proven Earth science and communication technology, and our extensive space systems expertise. The result has been a spacecraft that exceeded all of its major milestones during its primary mission. We are incredibly proud to be a part of this team.”
Dawn is the first mission of its kind, relying on solar electric ion propulsion, the world’s most advanced and efficient space propulsion technology, to travel to and orbit two interplanetary bodies in the main asteroid belt between Mars and Jupiter.
Orbital ATK’s Space Systems Group designed and built Dawn at the company’s facilities in Dulles, Virginia. Launched from Cape Canaveral, Florida in September 2007, Dawn embarked on a two-stop, interplanetary mission. During its nearly decade-long journey, Dawn traveled more than 3.5 billion miles or the equivalent of 140,000 trips around Earth’s equator. It delivered troves of important data to scientists worldwide with the first-ever, up-close look at two planetary bodies that date back to the formation of the solar system. In recognition of these achievements, the Dawn Project Team received prestigious awards, including the 2015 Robert J. Collier Trophy and the 2016 National Space Club’s Nelson P. Jackson Award.
In July 2011, Dawn reached its first destination, Vesta, the second most massive object in the main asteroid belt. It spent nearly 14 months orbiting and mapping Vesta, returning more than 30,000 images and other measurements of the protoplanet. In September 2012, Dawn departed Vesta in pursuit of its second destination, the dwarf planet Ceres, previously known as the largest unexplored world of the inner solar system. Dawn entered orbit around Ceres in March 2015. Since then, Dawn has returned nearly 40,000 images of intriguing topographical features, including the now-famous bright areas believed to be salt concentrations on the surface of Ceres. The quality of all images collected from both Vesta and Ceres substantially exceeded resolution previously available from the ground-based W.M. Keck Observatory and NASA’s Hubble Space Telescope. In fact, many of the images Dawn returned are more than 800 times the resolution available from Hubble observations.
“Dawn allowed us to become acquainted with two uncharted celestial bodies, each of which will help scientists better understand the origin of our solar system,” said Joe Makowski, Orbital ATK’s Dawn Program Manager. “The Dawn spacecraft and instruments proved their mettle throughout the primary mission, enabling great science in deep space.”
Dawn's mission is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. The University of California at Los Angeles (UCLA) is responsible for overall Dawn mission science. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
Post by: MattMason on 06/30/2016 06:19 pm
Didn't someone nail this prediction at the start of this thread? More cryo-geysers? Or is this phenomenon of a different variation and cause than Europa or that-Saturn-moon-I-can't-spell-that-begins-with-E?Enceladus (Enchiladas for the Latin impaired...)
Thank you.
And now I'm hungry on a planetary scale.
Post by: Sam Ho on 06/30/2016 07:42 pm
On June 30, just in time for the global celebration known as Asteroid Day, NASA's Dawn spacecraft completes its primary mission. The mission exceeded all expectations originally set for its exploration of protoplanet Vesta and dwarf planet Ceres.
The historic mission is the first to orbit two extraterrestrial solar system targets, and the first to orbit any object in the main asteroid belt, between Mars and Jupiter. On March 6, 2015, Dawn also became the first spacecraft to enter orbit around a dwarf planet.
An infographic highlights some of the accomplishments of Dawn's journey since launching in September 2007. Dawn has traveled 3.5 billion miles (5.6 billion kilometers) since launch, and has made 2,450 orbits around Vesta and Ceres. The spacecraft has returned about 69,000 images, combined, of both bodies.
Dawn's advanced ion propulsion system made it possible for the spacecraft to orbit two targets in the main asteroid belt. The spacecraft has logged about 48,000 hours of ion engine thrusting.
Scientists have learned a great deal about these unique, massive residents of the asteroid belt through data from the mission. Dawn has revealed that while Vesta is a dry body, Ceres could be as much as 25 percent water ice by mass. Dawn also discovered many intriguing features at both bodies -- Vesta is home to a mountain whose height is more than twice that of Mount Everest, and Ceres has a crater called Occator with mysterious bright features that continue to spark scientific investigation.
Dawn's mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, California, for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
News Media Contact
Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
[email protected]
2016-167
Post by: Star One on 07/01/2016 08:23 pm
Quote
In addition to the extension of the New Horizons mission, NASA determined that the Dawn spacecraft should remain at the dwarf planet Ceres, rather than changing course to the main belt asteroid Adeona.
Green noted that NASA relies on the scientific assessment by the Senior Review Panel in making its decision on which extended mission option to approve. “The long-term monitoring of Ceres, particularly as it gets closer to perihelion – the part of its orbit with the shortest distance to the sun -- has the potential to provide more significant science discoveries than a flyby of Adeona,” he said.
http://www.nasa.gov/feature/new-horizons-receives-mission-extension-to-kuiper-belt-dawn-to-remain-at-ceres
Post by: redliox on 07/01/2016 11:14 pm
Post by: baldusi on 07/01/2016 11:31 pm
Post by: clongton on 07/02/2016 12:37 am
Post by: Star One on 07/02/2016 08:20 am
Post by: redliox on 07/02/2016 10:05 am
For planetary protection how long does it have stable in its current orbit?
I seem to recall back in the 1970s, regarding Mars, there was an agreement to keep orbiters in space at least until 2050. No idea if they bother with setting 'time limits' nowadays, but in the case of Dawn there's minimal concern. It will still be several hundred kilometers above Ceres circling an airless asteroid with no direct friction to drag it down immediately. If anything drags down Dawn, it would have to be gravitational anomalies just like what the Moon does to orbiters around it. Otherwise, I see two outcomes for Dawn's post-operational future:
1) Retrieved in the far future for display in the Smithsonian.
2) Continues circling Ceres post-extinction of humanity until random meteoroid whacks it out of orbit.
I'm sure they will debate this concern before the extension's end in 2017, but I suspect for the reasons I mentioned few scientists will lose much sleep. If anything to mitigate concerns, they could raise Dawn's orbit higher and junk it there; I'm sure the SEP could manage that.
Post by: baldusi on 07/02/2016 05:12 pm
Post by: Blackstar on 07/02/2016 05:16 pm
If they keep finding interesting things they may design a sample return mission? Or another SEP orbiter for other Belt objects?
Sample return at those distances is tough because it takes a long time, adding to mission cost. I see that as an expensive mission. Not impossible, but the justification to do it has to be really good.
For other possible belt missions look at the Trojan asteroid mission proposals. There have been several over the years.
Post by: plutogno on 07/02/2016 05:30 pm
If anything drags down Dawn, it would have to be gravitational anomalies just like what the Moon does to orbiters around it.
actually, gravitational anomalies alone can't deorbit a satellite. you need a third, perturbing body like the Earth to do that. so an orbit around Ceres is theoretically eternal. in reality, solar radiation pressure will cause is to decay at one point
Post by: Bob Shaw on 07/02/2016 05:50 pm
I seem to recall back in the 1970s, regarding Mars, there was an agreement to keep orbiters in space at least until 2050. No idea if they bother with setting 'time limits' nowadays, but in the case of Dawn there's minimal concern. It will still be several hundred kilometers above Ceres circling an airless asteroid with no direct friction to drag it down immediately.
The Martian atmosphere extends further from the planet than does our own, and at high altitude is actually denser than our local example. Anything in an elliptical, or simply low, orbit is pretty vulnerable to drag - I doubt if such vehicles would last as long as the 2050s. Most orbiters are clean, but far from sterile, nor have any landers been sterilised since Viking. So, Planetary Protection at Mars has already suffered human compromise (not to mention Terrestrial meteorites over the ages).
I'm quite sorry that Dawn will be left at Ceres - hopefully the orbit of Dawn will be raised from the current low altitude before too long.
Post by: Star One on 07/02/2016 09:23 pm
I seem to recall back in the 1970s, regarding Mars, there was an agreement to keep orbiters in space at least until 2050. No idea if they bother with setting 'time limits' nowadays, but in the case of Dawn there's minimal concern. It will still be several hundred kilometers above Ceres circling an airless asteroid with no direct friction to drag it down immediately.
The Martian atmosphere extends further from the planet than does our own, and at high altitude is actually denser than our local example. Anything in an elliptical, or simply low, orbit is pretty vulnerable to drag - I doubt if such vehicles would last as long as the 2050s. Most orbiters are clean, but far from sterile, nor have any landers been sterilised since Viking. So, Planetary Protection at Mars has already suffered human compromise (not to mention Terrestrial meteorites over the ages).
I'm quite sorry that Dawn will be left at Ceres - hopefully the orbit of Dawn will be raised from the current low altitude before too long.
Studying Ceres as it comes in closer to the Sun seems a worthwhile scientific mission, so I don't think there is any need to be sorry it has been left in orbit around Ceres.
Post by: Sam Ho on 07/02/2016 10:20 pm
I seem to recall back in the 1970s, regarding Mars, there was an agreement to keep orbiters in space at least until 2050. No idea if they bother with setting 'time limits' nowadays, but in the case of Dawn there's minimal concern. It will still be several hundred kilometers above Ceres circling an airless asteroid with no direct friction to drag it down immediately.I'm quite sorry that Dawn will be left at Ceres - hopefully the orbit of Dawn will be raised from the current low altitude before too long.
Studying Ceres as it comes in closer to the Sun seems a worthwhile scientific mission, so I don't think there is any need to be sorry it has been left in orbit around Ceres.
There's no reason to raise Dawn's orbit. LAMO is stable for thousands of years and not a planetary protection problem. From a science perspective, LAMO is also as good as it gets. Lower orbits have very high propellant consumption.
http://dawnblog.jpl.nasa.gov/2014/08/31/dawn-journal-august-31/
Post by: catdlr on 07/08/2016 08:06 pm
NASA Goddard
Published on Jul 8, 2016
Permanently shadowed regions capable of accumulating surface ice were identified in the northern hemisphere of Ceres using images taken by NASA’s Dawn mission combined with sophisticated computer modeling of illumination.
https://youtu.be/aUZCwD2oCXs?t=001
https://youtu.be/aUZCwD2oCXs
Post by: hop on 07/12/2016 04:13 am
http://solarsystem.nasa.gov/docs/PMSR2016_Report_Final.pdf
Quote
DAWN–Good/Fair (145 Adeona).
The Panel was pleased that DAWN submitted an Extended Mission (EM) proposal unexpectedly.
The last minute determination of a viable extended mission required rapid proposal development/submission to meet the PMSR deadline, therefore eliciting a significant number of questions from the Panel prior to the face-to-face. This is the only mission that required the Panel to revisit initial voting and scoring.
...
The Panel found that visiting a new small body (Adeona) always has the potential for unanticipated, ground-breaking discoveries; yet remaining at Ceres does as well in compositionally interesting regions. Many discrepancies in the Adeona proposal were undoubtedly due to the hurried nature of its development, and the Panel found it lacking science traceability, specifics and justifications. For example, it did not clearly defined how the New Dawn objectives address Decadal questions and there is no direct link made between “Goals” in the Traceability Matrix and the Decadal, or indeed where the "goals" came from. Most critically lacking was a comparison of science achievable between Adeona and remaining at Ceres (requested via the descope). Additionally, the Panel was concerned about Dawn having achieved all Level 1 requirements prior to departing Ceres. The project response to this Panel question indicated that the results of the hydrogen mapping are not yet clear, and remaining at Ceres would lead to a 1.5x improvement in neutron signal/noise for hydrogen, an important issue in tracing water in the solar system.
Post by: Star One on 07/27/2016 04:39 pm
Quote
Asteroids provide fundamental clues to the formation and evolution of planetesimals. Collisional models based on the depletion of the primordial main belt of asteroids predict 10–15 craters >400 km should have formed on Ceres, the largest object between Mars and Jupiter, over the last 4.55 Gyr. Likewise, an extrapolation from the asteroid Vesta would require at least 6–7 such basins. However, Ceres’ surface appears devoid of impact craters >~280 km. Here, we show a significant depletion of cerean craters down to 100–150 km in diameter. The overall scarcity of recognizable large craters is incompatible with collisional models, even in the case of a late implantation of Ceres in the main belt, a possibility raised by the presence of ammoniated phyllosilicates. Our results indicate that a significant population of large craters has been obliterated, implying that long-wavelength topography viscously relaxed or that Ceres experienced protracted widespread resurfacing.
http://www.nature.com/ncomms/2016/160726/ncomms12257/abs/ncomms12257.html
Post by: Star One on 08/01/2016 07:26 pm
Quote
But how to decide between these two attractive possibilities? Some members of the Dawn team preferred continuing the exploration of Ceres and others preferred going to Adeona. Similarly, some people prefer cake and some prefer pie. (That's not a perfect example, because it's obvious cake is better, but you get the idea.)
NASA thoroughly evaluated the scientific potential and other aspects of the options. Part of this was an assessment by an independent group of esteemed scientists. The conclusion was that either would be valuable but that studying Ceres further was preferable.
From the perspective of your correspondent -- passionate about space exploration since the age of four, a professional scientist (as well as a scientist at heart), an engineer and a taxpayer -- this is a wonderful outcome. How could one want anything other than such a well-considered decision?
But how is it even possible that the team could have offered to NASA the option of visiting Adeona for the extended mission? We have emphasized for several years that Ceres would be Dawn's final home. If you had asked even as recently as early this year whether the spacecraft could leave Ceres (and many of you did), we would have responded that such a prospect was unrealistic and inconceivable (and we did). We have described in great detail how the failure of two of Dawn's four reaction wheels was so serious that it was only with heroic effort that the distant robot was able to complete its original assignments. We have explained repeatedly that the spacecraft will soon expend the last of its hydrazine propellant, then immediately lose the ability to point its solar arrays at the sun, its antenna at Earth, its scientific sensors at Ceres or its ion engine in the direction needed to fly elsewhere. Why the change now, and how could Dawn operate for a multiyear journey?
We have discussed in recent months how remarkably well the flight team has done in conserving hydrazine, significantly exceeding any reasonable expectations and thereby extending Dawn's functional lifetime. Moreover, mission controllers know that the probe consumes less hydrazine at higher altitudes. Contrary to many people's notions, the dwarf planet's gravity is appreciable, and operating so close to it requires a very high rate of hydrazine consumption. Dawn is circling only 240 miles (385 kilometers) above Ceres, closer than the International Space Station is to Earth. But during the long deep-space journey to Adeona, Dawn would use the precious propellant much more sparingly. So despite the loss of the two reaction wheels, under the expert guidance of its terrestrial colleagues, the ship could set sail once again for a new and distant land beyond the horizon.
http://www.planetary.org/blogs/guest-blogs/marc-rayman/20160730-dawn-journal-staying-at-ceres.html
Post by: Star One on 08/31/2016 10:15 pm
After studying Ceres for more than eight months from its low-altitude science orbit, NASA's Dawn spacecraft will move higher up for different views of the dwarf planet.
Dawn has delivered a wealth of images and other data from its current perch at 240 miles (385 kilometers) above Ceres' surface, which is closer to the dwarf planet than the International Space Station is to Earth. Now, the mission team is pivoting to consider science questions that can be examined from higher up.
After Dawn completed its prime mission on June 30, having surpassed all of its scientific objectives at Vesta and at Ceres, NASA extended the mission to perform new studies of Ceres. One of the factors limiting Dawn’s lifetime is the amount of hydrazine, the propellant needed to orient the spacecraft to observe Ceres and communicate with Earth. By going to a higher orbit at Ceres, Dawn will use the remaining hydrazine more sparingly, because it won't have to work as hard to counter Ceres' gravitational pull.
"Most spacecraft wouldn't be able to change their orbital altitude so easily. But thanks to Dawn's uniquely capable ion propulsion system, we can maneuver the ship to get the greatest scientific return from the mission," said Marc Rayman, chief engineer and mission director, based at NASA's Jet Propulsion Laboratory, Pasadena, California.
On Sept. 2, Dawn will begin spiraling upward to about 910 miles (1,460 kilometers) from Ceres. The altitude will be close to where Dawn was a year ago, but the orientation of the spacecraft's orbit -- specifically, the angle between the orbit plane and the sun -- will be different this time, so the spacecraft will have a different view of the surface.
The mission team is continuing to develop the extended mission itinerary and will submit a full plan to NASA next month.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
[email protected]
2016-227
Last Updated: Aug. 31, 2016
Editor: Martin Perez
Post by: Star One on 09/01/2016 08:56 pm
http://m.phys.org/news/2016-09-ceres-tiny-world-volcanoes-erupt.html
Post by: Star One on 09/19/2016 05:34 pm
http://www.universetoday.com/130898/phenomenal-new-view-ceres-lonely-mountain-reveals-signs-volcanic-activity/
Post by: Star One on 11/18/2016 08:16 pm
The brightest area on Ceres stands out amid shadowy, cratered terrain in a dramatic new view from NASA's Dawn spacecraft, taken as it looked off to the side of the dwarf planet. Dawn snapped this image on Oct. 16, from its fifth science orbit, in which the angle of the sun was different from that in previous orbits. Dawn was about 920 miles (1,480 kilometers) above Ceres when this image was taken -- an altitude the spacecraft had reached in early October.
Occator Crater, with its central bright region and secondary, less-reflective areas, appears quite prominent near the limb, or edge, of Ceres. At 57 miles (92 kilometers) wide and 2.5 miles (4 kilometers) deep, Occator displays evidence of recent geologic activity. The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below, froze and then sublimated, meaning it turned from ice into vapor.
The impact that formed the crater millions of years ago unearthed material that blanketed the area outside the crater, and may have triggered the upwelling of salty liquid.
"This image captures the wonder of soaring above this fascinating, unique world that Dawn is the first to explore," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory, Pasadena, California.
Dawn scientists also have released an image of Ceres that approximates how the dwarf planet's colors would appear to the human eye. This view, produced by the German Aerospace Center in Berlin, combines images taken from Dawn's first science orbit in 2015, using the framing camera's red, green and blue filters. The color was calculated based on the way Ceres reflects different wavelengths of light.
The spacecraft has gathered tens of thousands of images and other information from Ceres since arriving in orbit on March 6, 2015. After spending more than eight months studying Ceres at an altitude of about 240 miles (385 kilometers), closer than the International Space Station is to Earth, Dawn headed for a higher vantage point in August. In October, while the spacecraft was at its 920-mile altitude, it returned images and other valuable insights about Ceres.
On Nov. 4, Dawn began making its way to a sixth science orbit, which will be over 4,500 miles (7,200 kilometers) from Ceres. While Dawn needed to make several changes in its direction while spiraling between most previous orbits at Ceres, engineers have figured out a way for the spacecraft to arrive at this next orbit while the ion engine thrusts in the same direction that Dawn is already going. This uses less hydrazine and xenon fuel than Dawn's normal spiral maneuvers. Dawn should reach this next orbit in early December.
One goal of Dawn's sixth science orbit is to refine previously collected measurements. The spacecraft's gamma ray and neutron spectrometer, which has been investigating the composition of Ceres' surface, will characterize the radiation from cosmic rays unrelated to Ceres. This will allow scientists to subtract "noise" from measurements of Ceres, making the information more precise.
The spacecraft is healthy as it continues to operate in its extended mission phase, which began in July. During the primary mission, Dawn orbited and accomplished all of its original objectives at Ceres and protoplanet Vesta, which the spacecraft visited from July 2011 to September 2012.
Dawn's mission is managed by NASA's Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
News Media Contact
Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, CA
818-354-6425
[email protected]
2016-297
http://www.jpl.nasa.gov/news/news.php?release=2016-297
Post by: zubenelgenubi on 12/13/2016 06:40 pm
http://fallmeeting.agu.org/2016/media-center/press-conferences/#dawn
Quote
Dawn science update***
Thursday, 15 December
10:30 a.m.
NASA’s Dawn spacecraft has been orbiting dwarf planet Ceres since March 2015. Scientists will discuss new research on Ceres’ composition and some of its most intriguing features.
Participants:
Carol Raymond, NASA Jet Propulsion Laboratory, Pasadena, California, U.S.A.;
Thomas Prettyman, Planetary Science Institute, Tucson, Arizona, U.S.A.;
Norbert Schorghofer, University of Hawaii, Honolulu, Hawaii, U.S.A.;
Ralf Jaumann, German Aerospace Center, Washington, D.C., U.S.A.
Sessions: P41C, P43C, P54A
Watch at: https://livestream.com/accounts/2831286/events/6704756
Press conferences will be archived on the AGU YouTube channel (https://www.youtube.com/user/AGUvideos/videos).
Post by: Eric Hedman on 12/15/2016 06:30 pm
http://hosted.ap.org/dynamic/stories/U/US_SCI_DWARF_PLANET_MISSION?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2016-12-15-13-32-30 (http://hosted.ap.org/dynamic/stories/U/US_SCI_DWARF_PLANET_MISSION?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2016-12-15-13-32-30)
Post by: yg1968 on 01/01/2017 02:37 am
New Ceres Views as Dawn Moves Higher
[...]
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
On the same day, a very nice color image of Ceres was released:
https://www.nasa.gov/image-feature/jpl/pia21079/ceres-in-color
Post by: yg1968 on 01/01/2017 02:45 am
American Geophysical Union Fall Meeting 2016 press conferences:
http://fallmeeting.agu.org/2016/media-center/press-conferences/#dawnQuoteDawn science update***
Thursday, 15 December
10:30 a.m.
NASA’s Dawn spacecraft has been orbiting dwarf planet Ceres since March 2015. Scientists will discuss new research on Ceres’ composition and some of its most intriguing features.
Participants:
Carol Raymond, NASA Jet Propulsion Laboratory, Pasadena, California, U.S.A.;
Thomas Prettyman, Planetary Science Institute, Tucson, Arizona, U.S.A.;
Norbert Schorghofer, University of Hawaii, Honolulu, Hawaii, U.S.A.;
Ralf Jaumann, German Aerospace Center, Washington, D.C., U.S.A.
Sessions: P41C, P43C, P54A
Watch at: https://livestream.com/accounts/2831286/events/6704756
Press conferences will be archived on the AGU YouTube channel (https://www.youtube.com/user/AGUvideos/videos).
Here is the link to the archived video of the December 15th press conference:
https://www.youtube.com/watch?v=6X6MhN_Kdak
Post by: Star One on 02/07/2017 04:39 pm
http://www.centauri-dreams.org/?p=37096
Post by: Star One on 02/17/2017 05:48 pm
Quote
"The organic-rich areas include carbonate and ammoniated species, which are clearly Ceres' endogenous material, making it unlikely that the organics arrived via an external impactor," co-author Simone Marchi, a senior research scientist at the Southwest Research Institute in Boulder, Colorado, said in a statement.
In addition, the intense heat generated by an asteroid or comet strike likely would have destroyed the organics, further suggesting that the molecules are native to Ceres, study team members said.
The organics might have formed via reactions involving hot water, De Sanctis and her colleagues said. Indeed, "Ceres shows clear signatures of pervasive hydrothermal activity and aqueous alteration," they wrote in the new study.
Such activity likely would have taken place underground. Dawn mission scientists aren't sure yet how organics generated in the interior could make it up to the surface and leave the signatures observed by the spacecraft.
"The geological and morphological settings of Ernutet are still under investigation with the high-resolution data acquired in the last months, and we do not have a definitive answer for why Ernutet is so special," De Sanctis said.
It's already clear, however, that Ceres is a complex and intriguing world — one that astrobiologists are getting more and more excited about.
"In some ways, it is very similar to Europa and Enceladus," De Sanctis said, referring to ocean-harboring moons of Jupiter and Saturn, respectively.
"We see compounds on the surface of Ceres like the ones detected in the plume of Enceladus," she added. "Ceres' surface can be considered warmer with respect to the Saturnian and Jovian satellites, due to [its] distance from the sun. However, we do not have evidence of a subsurface ocean now on Ceres, but there are hints of subsurface recent fluids."
http://www.space.com/35729-dwarf-planet-ceres-organic-molecules.html
Post by: Sam Ho on 02/18/2017 04:03 pm
Dawn spacecraft data suggest organic materials are native to the dwarf planet
Boulder, Colo. — February 16, 2017 — NASA’s Dawn spacecraft recently detected organic-rich areas on Ceres. Scientists evaluated the geology of the regions to conclude that the organics are most likely native to the dwarf planet. Data from the spacecraft suggest that the interior of Ceres is the source of these organic materials, as opposed to arriving via impacting asteroids or comets, according to a paper published in the Feb. 17, 2017, issue of Science.
“This discovery of a locally high concentration of organics is intriguing, with broad implications for the astrobiology community,” said Dr. Simone Marchi, a senior research scientist at Southwest Research Institute and one of the authors of the paper. “Ceres has evidence of ammonia-bearing hydrated minerals, water ice, carbonates, salts, and now organic materials. With this new finding Dawn has shown that Ceres contains key ingredients for life.”
Ceres is believed to have originated about 4.5 billion years ago at the dawn of our solar system. Studying its organics can help explain the origin, evolution, and distribution of organic species across the solar system. Data from Dawn’s visible and infrared mapping spectrometer show an unusually high concentration of organic matter close to the 50-km diameter Ernutet crater in the northern hemisphere of Ceres. The distribution and characteristics of the organics seem to preclude association with any single crater. The largest concentration appears to drape discontinuously across the southwest floor and rim of Ernutet and onto an older, highly degraded crater. Other organic-rich areas are scattered to the northwest. While other scientists looked at the distribution and spectra of the materials, Marchi focused on the geological settings.
“The overall region is heavily cratered and appears to be ancient; however, the rims of Ernutet crater appear to be relatively fresh,” Marchi said. “The organic-rich areas include carbonate and ammoniated species, which are clearly Ceres’ endogenous material, making it unlikely that the organics arrived via an external impactor.”
Ceres shows clear signatures of pervasive hydrothermal activity, aqueous alteration and fluid mobility, so the organic-rich areas may be the result of internal processes. Dawn scientists will continue to study the dwarf planet to identify a viable method for transporting such material from the interior to the surface in the pattern observed.
These findings appear in the paper “Localized aliphatic organic material on the surface of Ceres” published in the Feb. 17, 2017, edition of the journal Science. Dawn’s mission to Ceres and Vesta, the two most massive bodies in the asteroid belt, is managed by the Jet Propulsion Laboratory for NASA’s Science Mission Directorate in Washington, D.C. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science.
Editors: Images to accompany this release are available at: http://www.swri.org/press/2017/ceres-organic-materials.htm.
http://www.swri.org/9what/releases/2017/ceres-organic-materials.htm
http://science.sciencemag.org/content/355/6326/719
Post by: Ben the Space Brit on 02/19/2017 02:38 pm
Post by: JH on 02/19/2017 06:05 pm
Question: At what point does the presence of organic and/or pre-biotic chemistry rule out ever allowing Dawn to crash-land on the body to prevent contamination?
It won't be an issue as Dawn will be left in its present orbit indefinitely. Perturbations to satellites of Ceres are small enough that the orbit will be stable for centuries.
Post by: Star One on 03/06/2017 08:28 pm
Quote
Among the most striking features on the surface of Ceres are the bright spots in the center of Occator crater which stood out already as NASA’s space probe Dawn approached the dwarf planet. Scientists under the leadership of the Max Planck Institute for Solar System Research (MPS) have now for the first time determined the age of this bright material, which consists mainly of deposits of special mineral salts. With about four million years only, these deposits are about 30 million years younger than the crater itself. This, as well as the distribution and nature of the bright material within the crater, suggests that Occator crater has been the scene of eruptive outbursts of subsurface brine over a long period and until almost recently. Ceres is thus the body closest to the Sun that shows cryovolcanic activity.
http://www.mps.mpg.de/Cryovolcanism-on-Dwarf-Planet-Ceres
Post by: Ben the Space Brit on 03/07/2017 03:49 pm
Post by: vjkane on 03/08/2017 05:19 am
Cryovulcanism so close to the Inner Planets? The next time a Discovery or New Frontiers-class slot comes up, I'm pretty sure there will be plenty of planetary scientists agitating for a lander for Occator Crater!I would be surprised if there isn't at least one Discovery proposal. A lander may be hard in a Discovery budget, though.
Post by: Zed_Noir on 03/08/2017 08:44 am
Cryovulcanism so close to the Inner Planets? The next time a Discovery or New Frontiers-class slot comes up, I'm pretty sure there will be plenty of planetary scientists agitating for a lander for Occator Crater!I would be surprised if there isn't at least one Discovery proposal. A lander may be hard in a Discovery budget, though.
Somewhat in jest. Since Dawn is available as comm relay for a while. Maybe a cheap carrier spacecraft with a small airbag lander with a hypergolic crusher stage. :)
Post by: Star One on 03/22/2017 09:26 pm
Dwarf planet Ceres may be hundreds of millions of miles from Jupiter, and even farther from Saturn, but the tremendous influence of gravity from these gas giants has an appreciable effect on Ceres' orientation. In a new study, researchers from NASA's Dawn mission calculate that the axial tilt of Ceres -- the angle at which it spins as it journeys around the sun -- varies widely over the course of about 24,500 years. Astronomers consider this to be a surprisingly short period of time for such dramatic deviations.
Changes in axial tilt, or "obliquity," over the history of Ceres are related to the larger question of where frozen water can be found on Ceres' surface, scientists report in the journal Geophysical Research Letters. Given conditions on Ceres, ice would only be able to survive at extremely cold temperatures -- for example, in areas that never see the sun.
"We found a correlation between craters that stay in shadow at maximum obliquity, and bright deposits that are likely water ice," said Anton Ermakov, postdoctoral researcher at NASA's Jet Propulsion Laboratory, Pasadena, California, and lead author of the study. "Regions that never see sunlight over millions of years are more likely to have these deposits."
Cycles of Obliquity
Throughout the last 3 million years, Ceres has gone through cycles where its tilt ranges from about 2 degrees to about 20 degrees, calculations indicate.
"We cannot directly observe the changes in Ceres' orientation over time, so we used the Dawn spacecraft's measurements of shape and gravity to precisely reconstruct what turned out to be a dynamic history," said Erwan Mazarico, a co-author at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
The last time the dwarf planet reached a maximum tilt, which was about 19 degrees, was 14,000 years ago, researchers said. For comparison, Earth is tilted 23.5 degrees. This significant tilt causes our planet to experience seasons: The northern hemisphere experiences summer when it is oriented toward the sun, and winter when it's pointed away from the sun. By contrast, Ceres' current tilt is about 4 degrees, so it will not have such strong seasonal effects over the course of a year there (which is about 4.6 Earth years).
How Obliquity Relates to Ice
When the axial tilt is small, relatively large regions on Ceres never receive direct sunlight, particularly at the poles. These persistently shadowed regions occupy an area of about 800 square miles (2,000 square kilometers). But when the obliquity increases, more of the craters in the polar regions receive direct exposure to the sun, and persistently shadowed areas only occupy 0.4 to 4 square miles (1 to 10 square kilometers). These areas on Ceres' surface, which stay in shadow even at high obliquity, may be cold enough to maintain surface ice, Dawn scientists said.
These craters with areas that stay in shadow over long periods of time are called "cold traps," because they are so cold and dark that volatiles -- substances easily vaporized -- that migrate into these areas can't escape, even over a billion years. A 2016 study by the Dawn team in Nature Astronomy found bright material in 10 of these craters, and data from Dawn's visible and infrared mapping spectrometer indicate that one of them contains ice.
The new study focused on polar craters and modeled how shadowing progresses as Ceres' axial tilt varies. In the northern hemisphere, only two persistently shadowed regions remain in shadow at the maximum 20-degree tilt. Both of these regions have bright deposits today. In the southern hemisphere, there are also two persistently shadowed regions at highest obliquity, and one of them clearly has a bright deposit.
Shadowed Regions in Context
Ceres is the third body in the solar system found to have permanently shadowed regions. Mercury and Earth's moon are the other two, and scientists believe they received their ice from impacting bodies. However, Mercury and the moon do not have such wide variability in their tilts because of the stabilizing gravitational influence of the sun and Earth, respectively. The origin of the ice in Ceres' cold traps is more mysterious -- it may come from Ceres itself, or may be delivered by impacts from asteroids and comets. Regardless, the presence of ice in cold traps could be related to a tenuous water atmosphere, which was detected by ESA's Herschel Space Observatory in 2012-13. Water molecules that leave the surface would fall back onto Ceres, with some landing in cold traps and accumulating there.
"The idea that ice could survive on Ceres for long periods of time is important as we continue to reconstruct the dwarf planet's geological history, including whether it has been giving off water vapor," said Carol Raymond, deputy principal investigator of the Dawn mission and study co-author, based at JPL.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://dawn.jpl.nasa.gov
http://www.nasa.gov/dawn
https://www.jpl.nasa.gov/news/news.php?feature=6787
Post by: Star One on 04/08/2017 09:23 pm
Scientists have long thought that Ceres may have a very weak, transient atmosphere, but mysteries lingered about its origin and why it's not always present. Now, researchers suggest that this temporary atmosphere appears to be related to the behavior of the sun, rather than Ceres' proximity to the sun. The study was conducted by scientists from NASA's Dawn mission and others who previously identified water vapor at Ceres using other observatories.
"We think the occurrence of Ceres' transient atmosphere is the product of solar activity," said Michaela Villarreal, lead author of the new study in the Astrophysical Journal Letters and researcher at the University of California, Los Angeles.
Ceres is the largest object in the asteroid belt that lies between Mars and Jupiter. When energetic particles from the sun hit exposed ice and ice near the surface of the dwarf planet, it transfers energy to the water molecules as they collide. This frees the water molecules from the ground, allowing them to escape and create a tenuous atmosphere that may last for a week or so.
"Our results also have implications for other airless, water-rich bodies of the solar system, including the polar regions of the moon and some asteroids," said Chris Russell, principal investigator of the Dawn mission, also at UCLA. "Atmospheric releases might be expected from their surfaces, too, when solar activity erupts."
Before Dawn arrived in orbit at Ceres in 2015, evidence for an atmosphere had been detected by some observatories at certain times, but not others, suggesting that it is a transient phenomenon. In 1991, the International Ultraviolet Explorer satellite detected hydroxyl emission from Ceres, but not in 1990. Then, in 2007, the European Southern Observatory's Very Large Telescope searched for a hydroxide emission, but came up empty. The European Space Agency's Herschel Space Observatory detected water in the possible weak atmosphere, or "exosphere," of Ceres on three occasions, but did not on a fourth attempt.
As Dawn began its thorough study of Ceres in March 2015, scientists found ample evidence for water in the form of ice. The spacecraft's gamma ray and neutron detector (GRaND) has found that the uppermost surface is rich in hydrogen, which is consistent with broad expanses of water ice. This ice is nearer to the surface at higher latitudes, where temperatures are lower, a 2016 study published in the journal Science found. Ice has been detected directly at the small bright crater called Oxo and in at least one of the craters that are persistently in shadow in the northern hemisphere. Other research has suggested that persistently shadowed craters are likely to harbor ice. Additionally, the shapes of craters and other features are consistent with significant water-ice content in the crust.
Because of this evidence for abundant ice, many scientists think that Ceres' exosphere is created in a process similar to what occurs on comets, even though they are much smaller. In that model, the closer Ceres gets to the sun, the more water vapor is released because of ice sublimating near or at the surface.
But the new study suggests comet-like behavior may not explain the mix of detections and non-detections of a weak atmosphere.
"Sublimation probably is present, but we don't think it's significant enough to produce the amount of exosphere that we're seeing," Villarreal said.
Villarreal and colleagues showed that past detections of the transient atmosphere coincided with higher concentrations of energetic protons from the sun. Non-detections coincided with lower concentrations of these particles. What's more, the best detections of Ceres' atmosphere did not occur at its closest approach to the sun. This suggests that solar activity, rather than Ceres' proximity to the sun, is a more important factor in generating an exosphere.
The research began with a 2016 Science study led by Chris Russell. The study, using GRaND data, suggested that, during a six-day period in 2015, Ceres had accelerated electrons from the solar wind to very high energies.
In its orbital path, Ceres is currently getting closer to the sun. But the sun is now in a particularly quiet period, expected to last for several more years. Since their results indicate Ceres' exosphere is related to solar activity, study authors are predicting that the dwarf planet will have little to no atmosphere for some time. However, they recommend that other observatories monitor Ceres for future emissions.
Dawn is now in its extended mission and studying Ceres in a highly elliptical orbit. Engineers are maneuvering the spacecraft to a different orbital plane so that Ceres can be viewed in a new geometry. The primary science objective is to measure cosmic rays to help determine which chemical elements lie near the surface of Ceres. As a bonus, in late April, the sun will be directly behind Dawn, when the spacecraft is at an altitude of about 12,300 miles (20,000 kilometers). Ceres will appear brighter than before in that configuration, and perhaps reveal more secrets about its composition and history.
The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
http://dawn.jpl.nasa.gov/mission
More information about Dawn is available at the following sites:
http://www.nasa.gov/dawn
http://dawn.jpl.nasa.gov
News Media Contact
Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, CA
818-354-6425
[email protected]
2017-097
https://www.jpl.nasa.gov/news/news.php?release=2017-098
Post by: eeergo on 04/26/2017 08:30 pm
Post by: vjkane on 04/26/2017 08:49 pm
Third reaction wheel failure: https://solarsystem.nasa.gov/news/2017/04/26/dawn-observing-ceres-3rd-reaction-wheel-malfunctions . No important impact foreseen for now, although of course there is no redundancy left even in the custom hybrid (CMG/RCS) attitude control mode that's left.If you'll remember, the Dawn team proposed an extended mission to flyby a 3rd asteroid. I believe that that mission was designed so it could be done only using the thrusters for attitude control. Anyone know more?
Post by: as58 on 04/26/2017 09:52 pm
Third reaction wheel failure: https://solarsystem.nasa.gov/news/2017/04/26/dawn-observing-ceres-3rd-reaction-wheel-malfunctions . No important impact foreseen for now, although of course there is no redundancy left even in the custom hybrid (CMG/RCS) attitude control mode that's left.If you'll remember, the Dawn team proposed an extended mission to flyby a 3rd asteroid. I believe that that mission was designed so it could be done only using the thrusters for attitude control. Anyone know more?
Yes, that was said in the senior review evaluation (https://solarsystem.nasa.gov/docs/PMSR2016_Report_Final.pdf)
page 3, 2nd paragraph: "...as wheels are not needed in this Adeona EM."
Post by: Hungry4info3 on 04/26/2017 10:59 pm
If you'll remember, the Dawn team proposed an extended mission to flyby a 3rd asteroid. I believe that that mission was designed so it could be done only using the thrusters for attitude control. Anyone know more?I don't know about the attitude control plan for that hypothetical scenario, but I do know the 3rd asteroid visit was not chosen as the end-of-mission architecture for Dawn.
https://www.nasa.gov/feature/new-horizons-receives-mission-extension-to-kuiper-belt-dawn-to-remain-at-ceres/
Post by: Star One on 05/17/2017 07:36 pm
https://astronomynow.com/2017/05/17/movie-shows-ceres-at-opposition-from-sun/
Post by: Star One on 06/18/2017 06:41 pm
Dawn mission managers await NASA decision on spacecraft’s future
https://spaceflightnow.com/2017/06/17/dawn-mission-managers-await-nasa-decision-on-spacecrafts-future/
Post by: Star One on 07/06/2017 04:48 pm
Quote
"NASA’s Planetary Science Division has received and is now reviewing a report from an independent science review panel with regard to Dawn’s completion of Level 1 science requirements at Ceres,” Cantillo told SpaceNews.
That review is required before NASA makes a decision on Dawn’s future. The spacecraft could remain in orbit around Ceres or “use its remaining fuel to travel to another asteroid,” she said.
Cantillo said that “points of clarification” about the report are currently being discussed are part of the overall science review of the mission. “Once completed, a decision will be made, most likely in the next 30–60 days,” she said. Spacecraft operations will continue during the review process.
A project scientist said last month that the mission was considering a flyby. “It’s an option,” Carol Raymond, deputy principal investigator for Dawn at the Jet Propulsion Laboratory, said at a June 13 meeting of NASA’s Small Bodies Assessment Group (SBAG). She said then that the mission was “in the process of discussing with NASA options for a second extended mission” but declined to give additional details about those options.
http://spacenews.com/nasa-reviews-options-for-dawn-extended-mission/
Post by: vjkane on 07/06/2017 05:48 pm
NASA reviews options for Dawn extended missionI don't know if the astrodynamics work out, but my favorite choice would be 2 Pallas. It makes an ecliptic plane crossing sometime in the next few years as I recall. Probably just wishful thinking, though.QuoteThat review is required before NASA makes a decision on Dawn’s future. The spacecraft could remain in orbit around Ceres or “use its remaining fuel to travel to another asteroid,” she said.
A project scientist said last month that the mission was considering a flyby. “It’s an option,” Carol Raymond, deputy principal investigator for Dawn at the Jet Propulsion Laboratory, said at a June 13 meeting of NASA’s Small Bodies Assessment Group (SBAG). She said then that the mission was “in the process of discussing with NASA options for a second extended mission” but declined to give additional details about those options.
http://spacenews.com/nasa-reviews-options-for-dawn-extended-mission/
Post by: Blackstar on 07/06/2017 05:57 pm
NASA reviews options for Dawn extended missionI don't know if the astrodynamics work out, but my favorite choice would be 2 Pallas. It makes an ecliptic plane crossing sometime in the next few years as I recall. Probably just wishful thinking, though.QuoteThat review is required before NASA makes a decision on Dawn’s future. The spacecraft could remain in orbit around Ceres or “use its remaining fuel to travel to another asteroid,” she said.
A project scientist said last month that the mission was considering a flyby. “It’s an option,” Carol Raymond, deputy principal investigator for Dawn at the Jet Propulsion Laboratory, said at a June 13 meeting of NASA’s Small Bodies Assessment Group (SBAG). She said then that the mission was “in the process of discussing with NASA options for a second extended mission” but declined to give additional details about those options.
http://spacenews.com/nasa-reviews-options-for-dawn-extended-mission/
Didn't their proposal last year require an immediate go decision in order to hit their preferred rendezvous? I bet what they can do depends upon the timing.
Post by: redliox on 07/06/2017 06:59 pm
Didn't their proposal last year require an immediate go decision in order to hit their preferred rendezvous? I bet what they can do depends upon the timing.
Yeah I swore I heard about similar plans before. Wasn't the ruling then that keeping Dawn in orbit was of better use than a flyby? However, given Dawn's been at Ceres for a solid 2 years now (with Vesta just over a year for comparison) I wouldn't have any objection sending it off for a final flyby at a new target before ending the mission.
When I did a quick check via Wiki Pallas and Adeona were the previously suggested targets. I'm curious if either remains viable although I presume a totally new target is one the menu.
Post by: Blackstar on 07/06/2017 09:31 pm
Yeah I swore I heard about similar plans before. Wasn't the ruling then that keeping Dawn in orbit was of better use than a flyby? However, given Dawn's been at Ceres for a solid 2 years now (with Vesta just over a year for comparison) I wouldn't have any objection sending it off for a final flyby at a new target before ending the mission.
Read the article, which mentions that there was concern about them achieving all their Level 1 science goals at Ceres. So they need to demonstrate that they have done that before they can argue that the spacecraft should go somewhere else. Can't have your pudding until you eat all your meat.
Post by: vjkane on 07/06/2017 10:24 pm
I read the Senior Review report. There top concerned seemed to be that the scientific case for visiting another asteroid instead of anally completing their mission goals at Ceres hadn't been made. Presumably all those missions goals are done (at least those that don't burn through fuel too quickly). Also presumably the Dawn team learned and has more time to prepare the science case for visiting another asteroid.Yeah I swore I heard about similar plans before. Wasn't the ruling then that keeping Dawn in orbit was of better use than a flyby? However, given Dawn's been at Ceres for a solid 2 years now (with Vesta just over a year for comparison) I wouldn't have any objection sending it off for a final flyby at a new target before ending the mission.
Read the article, which mentions that there was concern about them achieving all their Level 1 science goals at Ceres. So they need to demonstrate that they have done that before they can argue that the spacecraft should go somewhere else. Can't have your pudding until you eat all your meat.
Post by: Blackstar on 07/07/2017 12:48 am
I read the Senior Review report. There top concerned seemed to be that the scientific case for visiting another asteroid instead of anally completing their mission goals at Ceres hadn't been made. Presumably all those missions goals are done (at least those that don't burn through fuel too quickly). Also presumably the Dawn team learned and has more time to prepare the science case for visiting another asteroid.Yeah I swore I heard about similar plans before. Wasn't the ruling then that keeping Dawn in orbit was of better use than a flyby? However, given Dawn's been at Ceres for a solid 2 years now (with Vesta just over a year for comparison) I wouldn't have any objection sending it off for a final flyby at a new target before ending the mission.
Read the article, which mentions that there was concern about them achieving all their Level 1 science goals at Ceres. So they need to demonstrate that they have done that before they can argue that the spacecraft should go somewhere else. Can't have your pudding until you eat all your meat.
So this brings up a question that I don't know enough about to understand: is it possible for a mission to not achieve its Level 1 goals but instead conduct even more important science? Has that ever happened?
I can sort of imagine how that could happen--a rover goes looking for geology stuff and instead finds life, so the mission gives up on the geology goals and just mucks around with the goo. But I wonder where adherence to Level 1 goals might actually not be the best science approach once a mission is underway.
Post by: vjkane on 07/07/2017 01:47 am
I believe that Dawn long ago achieved its level 1 goals at Ceres. The final extension refined measurements supporting those goals.I read the Senior Review report. There top concerned seemed to be that the scientific case for visiting another asteroid instead of anally completing their mission goals at Ceres hadn't been made. Presumably all those missions goals are done (at least those that don't burn through fuel too quickly). Also presumably the Dawn team learned and has more time to prepare the science case for visiting another asteroid.Yeah I swore I heard about similar plans before. Wasn't the ruling then that keeping Dawn in orbit was of better use than a flyby? However, given Dawn's been at Ceres for a solid 2 years now (with Vesta just over a year for comparison) I wouldn't have any objection sending it off for a final flyby at a new target before ending the mission.
Read the article, which mentions that there was concern about them achieving all their Level 1 science goals at Ceres. So they need to demonstrate that they have done that before they can argue that the spacecraft should go somewhere else. Can't have your pudding until you eat all your meat.
So this brings up a question that I don't know enough about to understand: is it possible for a mission to not achieve its Level 1 goals but instead conduct even more important science? Has that ever happened?
I can sort of imagine how that could happen--a rover goes looking for geology stuff and instead finds life, so the mission gives up on the geology goals and just mucks around with the goo. But I wonder where adherence to Level 1 goals might actually not be the best science approach once a mission is underway.
I believe that the Senior Review panel's logic was, the asteroid flyby wasn't defined well enough to be evaluated and given that, the mission should stay at Ceres. The current review may be evaluating whether or not Dawn can do anything more useful at Ceres given that it has to remain in a distant orbit. If the reaction wheels had remained healthy, I could see them going for a very low orbit for targeted imaging and higher resolution GRS measurements.
Post by: JH on 07/07/2017 01:47 am
So this brings up a question that I don't know enough about to understand: is it possible for a mission to not achieve its Level 1 goals but instead conduct even more important science? Has that ever happened?
Something close to that happened with Cassini. After the plumes were discovered at Enceladus, a number of flybys of other moons that had been planned were cancelled in order to make room for more of Enceladus. Of course, given subsequent extensions of the mission, anything that was axed because of this has been recovered.
Post by: Nomadd on 07/07/2017 03:23 am
I've read so many versions of the Voyager tale that I can't keep them straight, but didn't Voyager 2 have to give up some science at Saturn and Titan to take the road to Uranus and Neptune? Or doesn't that count because Voyager 1 took up the slack?
So this brings up a question that I don't know enough about to understand: is it possible for a mission to not achieve its Level 1 goals but instead conduct even more important science? Has that ever happened?
Post by: Req on 07/07/2017 04:45 am
I've read so many versions of the Voyager tale that I can't keep them straight, but didn't Voyager 2 have to give up some science at Saturn and Titan to take the road to Uranus and Neptune? Or doesn't that count because Voyager 1 took up the slack?
So this brings up a question that I don't know enough about to understand: is it possible for a mission to not achieve its Level 1 goals but instead conduct even more important science? Has that ever happened?
Titan was considered such an important science goal that Voyager 1 was sent off the plane of the solar system never to encounter anything again to get a good Titan observation campaign. It was a major let down, but that's how it goes sometimes.
Post by: Star One on 07/07/2017 07:02 am
Well I suppose if nothing else they learnt what instruments do and don't give you science at Titan.I've read so many versions of the Voyager tale that I can't keep them straight, but didn't Voyager 2 have to give up some science at Saturn and Titan to take the road to Uranus and Neptune? Or doesn't that count because Voyager 1 took up the slack?
So this brings up a question that I don't know enough about to understand: is it possible for a mission to not achieve its Level 1 goals but instead conduct even more important science? Has that ever happened?
Titan was considered such an important science goal that Voyager 1 was sent off the plane of the solar system never to encounter anything again to get a good Titan observation campaign. It was a major let down, but that's how it goes sometimes.
Post by: ugordan on 07/07/2017 08:07 am
Titan was considered such an important science goal that Voyager 1 was sent off the plane of the solar system never to encounter anything again to get a good Titan observation campaign. It was a major let down, but that's how it goes sometimes.Well I suppose if nothing else they learnt what instruments do and don't give you science at Titan.
Also, IIRC the radio science occultation of Titan was crucial in enabling the Huygens probe by providing us with the temperature and pressure profile of the atmosphere so it wasn't all in vain.
Post by: yg1968 on 10/20/2017 02:08 am
https://www.jpl.nasa.gov/news/news.php?feature=6980
Post by: Star One on 10/20/2017 10:15 am
Dawn Mission Extended at Ceres:
https://www.jpl.nasa.gov/news/news.php?feature=6980
For a second time they’ve been blocked from moving it on to another target.
Post by: as58 on 10/20/2017 10:22 am
Post by: redliox on 10/20/2017 03:17 pm
Dawn Mission Extended at Ceres:
https://www.jpl.nasa.gov/news/news.php?feature=6980
For a second time they’ve been blocked from moving it on to another target.
Poor Dawn, rock blocked twice in a row now... ;)
Hopefully this new mission extension will be worth it. At the least we're getting maps of the solar system's largest asteroid. Who knows, if something interesting is found perhaps a lander could be in the works, so long as it meets cleanliness standards of course.
Post by: Star One on 10/20/2017 04:55 pm
Dawn Mission Extended at Ceres:
https://www.jpl.nasa.gov/news/news.php?feature=6980
For a second time they’ve been blocked from moving it on to another target.
Poor Dawn, rock blocked twice in a row now... ;)
Hopefully this new mission extension will be worth it. At the least we're getting maps of the solar system's largest asteroid. Who knows, if something interesting is found perhaps a lander could be in the works, so long as it meets cleanliness standards of course.
I hope this new lower orbit will be stable for a long time going forward.
Post by: vjkane on 10/21/2017 03:27 am
On the other hand, Ceres is likely to be a serious candidate for future exploration and any more information we can get there will help in planning those missions. I hope that the camera and visible-infrared spectrometer can get twice the resolution of the previous lowest orbit, but there is smear to be worried about.
Post by: zubenelgenubi on 10/23/2017 03:55 pm
<snip>
On the other hand, Ceres is likely to be a serious candidate for future exploration and any more information we can get there will help in planning those missions. I hope that the camera and visible-infrared spectrometer can get twice the resolution of the previous lowest orbit, but there is smear to be worried about.
From the press release Dawn Mission Extended at Ceres (https://www.jpl.nasa.gov/news/news.php?feature=6980)
Quote
A priority of the second Ceres mission extension is collecting data with Dawn's gamma ray and neutron spectrometer, which measures the number and energy of gamma rays and neutrons. This information is important for understanding the composition of Ceres' uppermost layer and how much ice it contains.
The spacecraft also will take visible-light images of Ceres' surface geology with its camera, as well as measurements of Ceres' mineralogy with its visible and infrared mapping spectrometer.
The extended mission at Ceres additionally allows Dawn to be in orbit while the dwarf planet goes through perihelion, its closest approach to the Sun, which will occur in April 2018. At closer proximity to the Sun, more ice on Ceres' surface may turn to water vapor, which may in turn contribute to the weak transient atmosphere detected by the European Space Agency's Herschel Space Observatory before Dawn's arrival. Building on Dawn's findings, the team has hypothesized that water vapor may be produced in part from energetic particles from the Sun interacting with ice in Ceres' shallow surface.Scientists will combine data from ground-based observatories with Dawn's observations to further study these phenomena as Ceres approaches perihelion.
Post by: zubenelgenubi on 10/23/2017 03:59 pm
I hope this new lower orbit will be stable for a long time going forward.
From the press release Dawn Mission Extended at Ceres (https://www.jpl.nasa.gov/news/news.php?feature=6980)
Quote
The spacecraft will continue at Ceres for the remainder of its science investigation and will remain in a stable orbit indefinitely after its hydrazine fuel runs out.
The Dawn flight team is studying ways to maneuver Dawn into a new elliptical orbit, which may take the spacecraft to less than 120 miles (200 kilometers) from the surface of Ceres at closest approach. Previously, Dawn's lowest altitude was 240 miles (385 kilometers).
<snip>
The Dawn team is currently refining its plans for this next and final chapter of the mission. Because of its commitment to protect Ceres from Earthly contamination, Dawn will not land or crash into Ceres. Instead, it will carry out as much science as it can in its final planned orbit, where it will stay even after it can no longer communicate with Earth. Mission planners estimate the spacecraft can continue operating until the second half of 2018.
Post by: catdlr on 10/27/2017 03:54 am
Quote
Minerals containing water are widespread on Ceres, suggesting the dwarf planet may have had a global ocean in the past. What became of that ocean? Could Ceres still have liquid today? Two new studies from NASA's Dawn mission shed light on these questions.
The Dawn team found that Ceres' crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and that this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres' rigid surface crust, which could be the signature of residual liquid left over from the ocean, too.
"More and more, we are learning that Ceres is a complex, dynamic world that may have hosted a lot of liquid water in the past, and may still have some underground," said Julie Castillo-Rogez, Dawn project scientist and co-author of the studies, based at NASA's Jet Propulsion Laboratory, Pasadena, California.
Source: https://www.jpl.nasa.gov/news/news.php?feature=6982
Post by: vjkane on 10/27/2017 05:20 am
Post by: Star One on 10/27/2017 06:22 am
I expect that there will be a major push by several groups in the planetary science community to get a return mission prioritized by the next Decadal Survey.
I imagine it’s both easier and cheaper to formulate a mission to Ceres than it is to certain other interesting targets in the Solar System.
Post by: vjkane on 10/27/2017 06:32 am
For an orbiter mission with improved instruments (e.g., higher resolution, better spectral coverage) I'd agree although I believe that a SEP engine is a necessity. If there's a desire for a lander to for example, search for organics, that gets much more difficult.I expect that there will be a major push by several groups in the planetary science community to get a return mission prioritized by the next Decadal Survey.
I imagine it’s both easier and cheaper to formulate a mission to Ceres than it is to certain other interesting targets in the Solar System.
I think that this finding also would raise the priority of visiting asteroids with active venting to broaden our understanding and enable cheap in situ sampling
Post by: Star One on 10/27/2017 06:39 am
For an orbiter mission with improved instruments (e.g., higher resolution, better spectral coverage) I'd agree although I believe that a SEP engine is a necessity. If there's a desire for a lander to for example, search for organics, that gets much more difficult.I expect that there will be a major push by several groups in the planetary science community to get a return mission prioritized by the next Decadal Survey.
I imagine it’s both easier and cheaper to formulate a mission to Ceres than it is to certain other interesting targets in the Solar System.
I think that this finding also would raise the priority of visiting asteroids with active venting to broaden our understanding and enable cheap in situ sampling
I’d thought a lander at Ceres is still an easier bet than an lander at Europa for example.
Post by: vjkane on 10/27/2017 07:25 am
A lot easier but still harder than an orbiter. Especially if you want to target the rough terrain where the most interesting stuff seems to be.For an orbiter mission with improved instruments (e.g., higher resolution, better spectral coverage) I'd agree although I believe that a SEP engine is a necessity. If there's a desire for a lander to for example, search for organics, that gets much more difficult.I expect that there will be a major push by several groups in the planetary science community to get a return mission prioritized by the next Decadal Survey.
I imagine it’s both easier and cheaper to formulate a mission to Ceres than it is to certain other interesting targets in the Solar System.
I think that this finding also would raise the priority of visiting asteroids with active venting to broaden our understanding and enable cheap in situ sampling
I’d thought a lander at Ceres is still an easier bet than an order at Europa for example.
Post by: zubenelgenubi on 10/27/2017 03:46 pm
A lot easier but still harder than an orbiter. Especially if you want to target the rough terrain where the most interesting stuff seems to be.For an orbiter mission with improved instruments (e.g., higher resolution, better spectral coverage) I'd agree although I believe that a SEP engine is a necessity. If there's a desire for a lander to for example, search for organics, that gets much more difficult.I expect that there will be a major push by several groups in the planetary science community to get a return mission prioritized by the next Decadal Survey.
I imagine it’s both easier and cheaper to formulate a mission to Ceres than it is to certain other interesting targets in the Solar System.
I think that this finding also would raise the priority of visiting asteroids with active venting to broaden our understanding and enable cheap in situ sampling
I’d thought a lander at Ceres is still an easier bet than an order at Europa for example.
What resolution imagery would a mission planning team need to confidently choose a landing site on Ceres?
Do we have sufficiently-resolved imagery now from Dawn?
Or will we, if imagery is taken from a lower-periaspse orbit during the recently-approved (probably final) extension of Dawn's operations?
Or do we need a 2nd generation Ceres orbiter to provide imagery to choose a landing site with confidence?
Post by: vjkane on 10/28/2017 07:30 am
What resolution imagery would a mission planning team need to confidently choose a landing site on Ceres?
Do we have sufficiently-resolved imagery now from Dawn?
Or will we, if imagery is taken from a lower-periaspse orbit during the recently-approved (probably final) extension of Dawn's operations?
Or do we need a 2nd generation Ceres orbiter to provide imagery to choose a landing site with confidence?
The best current resolution is ~35 m/pixel, so the smallest objects visible are twice that and more securely triple that resolution. The new orbit has the potential to half that resolution, but there may be problems with smearing; we will have to wait for more details.
If the salt eruption sites are the target sites, those have looked like very rough terrain to me, so I'm sure that a lander mission manager would like better resolution to pick likely landing spots. Even with that, I suspect a lander would use terrain hazard avoidance navigation to pick an acceptable location.
If I were planning a mission, I'd also look at an imaging spectrometer with both higher spatial and spectral resolution to better nail down the surface composition and tie it to geomorphology (which records the physical processes that shaped the surface). Current generation gamma-ray and neutron spectrometers also are more sensitive and can be made to have higher spatial resolution -- the Russian instrument on the Mars Trace Gas orbiter is a good example.
Ultimately, though, you will want instruments on the ground to really understand what the interior material is.
Post by: the_other_Doug on 10/31/2017 02:11 am
What resolution imagery would a mission planning team need to confidently choose a landing site on Ceres?
Do we have sufficiently-resolved imagery now from Dawn?
Or will we, if imagery is taken from a lower-periaspse orbit during the recently-approved (probably final) extension of Dawn's operations?
Or do we need a 2nd generation Ceres orbiter to provide imagery to choose a landing site with confidence?
The best current resolution is ~35 m/pixel, so the smallest objects visible are twice that and more securely triple that resolution. The new orbit has the potential to half that resolution, but there may be problems with smearing; we will have to wait for more details.
If the salt eruption sites are the target sites, those have looked like very rough terrain to me, so I'm sure that a lander mission manager would like better resolution to pick likely landing spots. Even with that, I suspect a lander would use terrain hazard avoidance navigation to pick an acceptable location.
If I were planning a mission, I'd also look at an imaging spectrometer with both higher spatial and spectral resolution to better nail down the surface composition and tie it to geomorphology (which records the physical processes that shaped the surface). Current generation gamma-ray and neutron spectrometers also are more sensitive and can be made to have higher spatial resolution -- the Russian instrument on the Mars Trace Gas orbiter is a good example.
Ultimately, though, you will want instruments on the ground to really understand what the interior material is.
Remember, Ceres has very low surface gravity; even on the largest asteroid in the system, landing will more resemble a docking. In fact, for many of the operations they will want to do on a lander, there will be significant mooring issues; movement of mass within the lander will tend to make it bounce around, and even bounce off the surface. So, "rugged" terrain is unlikely to sink you, and you can likely orient your instruments from pretty much any landing angle, if you design them for that.
On the other hand, this means that a very little amount of fuel would let you hop from one interesting site to another. Ceres is not for rovers; it's for hoppers...
Post by: redliox on 10/31/2017 04:57 am
Remember, Ceres has very low surface gravity; even on the largest asteroid in the system, landing will more resemble a docking. In fact, for many of the operations they will want to do on a lander, there will be significant mooring issues; movement of mass within the lander will tend to make it bounce around, and even bounce off the surface. So, "rugged" terrain is unlikely to sink you, and you can likely orient your instruments from pretty much any landing angle, if you design them for that.
On the other hand, this means that a very little amount of fuel would let you hop from one interesting site to another. Ceres is not for rovers; it's for hoppers...
With just under 3 percent of Earth's gravity, indeed. I wouldn't call it micro-gravity like the space station or asteroids, but it certainly is the borderline between micro and macro gravity. Something like a more robust version of the Philae lander could work.
The hopper idea is a good point. Wheels, unless they spun very slow (which would cause complications in overcoming any rugged regolith), would potentially hurl the rover into the air. A further thought for hopping could be whether or not gas jets could be used to hop instead of the leftover descent fuel. Either way, there'd be a limited amount of fuel for hopping.
There could be a pattern for hopping on Ceres (or perhaps any small body): a tall vertical hop to obtain long range and 3D imagery, followed by a low but reaching horizontal hop using the aforementioned imaging for guidance. Without an atmosphere, there couldn't be a helicopter scout like the next Mars rover could use, but hopping itself could provide opportunities for significant mapping.
Post by: catdlr on 12/13/2017 03:25 am
source: https://www.jpl.nasa.gov/news/news.php?feature=7022
Video: https://www.jpl.nasa.gov/video/details.php?id=1516
Post by: Star One on 12/15/2017 08:36 pm
Quote
“We’re going to be using an elliptical orbit to dive closer to the surface than we have before, down to 30 kilometers altitude,” said Carol Raymond, deputy principal investigator for Dawn during an Dec. 12 briefing about the mission at the Fall Meeting of the American Geophysical Union here. That altitude is significantly lower than what NASA stated when the agency announced the new extended mission.
Those close approaches will provide higher resolution and more accurate measurements of the chemistry of Ceres’ surface, as well as “unprecedented” high-resolution images of selected features. “We’re aiming to test our ideas about the origin and evolution of Ceres,” she said.
http://spacenews.com/dawn-to-fly-closer-to-ceres-than-ever-in-missions-final-phase/
Post by: zubenelgenubi on 06/14/2018 02:05 pm
http://www.skyandtelescope.com/astronomy-news/dawns-new-final-orbit-ceres/
NASA's Dawn spacecraft has entered a new and final orbit that will take it less than 30 miles above the surface of asteroid Ceres
Quote
The new orbit has a periapsis of less than 48 km above the pockmarked surface of Ceres and an apoapsis of 4,000 km.
<snip>
Attaining a low orbit around Ceres object is no mean feat, as the asteroid's gravitational field is lumpy due to the asteroid's uneven composition. NASA engineers looked at over 45,000 possible trajectories before settling on the solution. A lower orbit will allow researchers to map Ceres's gravitational field and hence its internal mass distribution.
<snip>
There's also a specific reason for the 27-hour, 13-minute orbit: This puts Dawn in a 3:1 resonant orbit with the asteroid, which rotates once every 9 hours, 4 minutes. Engineers are targeting several successive orbits over Occator crater.
<snip>
In its last months Dawn will map Ceres in unprecedented detail while continuing to use its instruments to collect neutron and gamma-ray spectra, which probe the surface's chemical composition.
Post by: theinternetftw on 06/14/2018 07:11 pm
All from here https://dawn.jpl.nasa.gov/multimedia/images/
<technical-note>
If you download those images, don't do it from Chrome. JPL's CDN is set up to return WebP images when asked (which Chrome does). This means even though the file extension still says jpeg, when you download it, it'll be WebP, and the image viewer in windows will fail to open it.
</technical-note>
Post by: Star One on 07/03/2018 10:16 am
NASA's Dawn spacecraft reached its lowest-ever and final orbit around dwarf planet Ceres on June 6 and has been returning thousands of stunning images and other data.
The flight team maneuvered the spacecraft into an orbit that dives 22 miles (35 kilometers) above the surface of Ceres and viewed Occator Crater, site of the famous bright deposits, and other intriguing regions. In more than three years of orbiting Ceres, Dawn's lowest altitude before this month was 240 miles (385 kilometers), so the data from this current orbit bring the dwarf planet into much sharper focus.
These low orbits have revealed unprecedented details of the relationships between bright and dark materials in the region of Vinalia Faculae. Dawn's visible and infrared mapping spectrometer had previously found the bright deposits to be made of sodium carbonate, a material commonly found in evaporite deposits on Earth. Last week Dawn fired its ion engine, possibly for the final time, to fly nearer Cerealia Facula, the large deposit of sodium carbonate in the center of Occator Crater.
"Acquiring these spectacular pictures has been one of the greatest challenges in Dawn's extraordinary extraterrestrial expedition, and the results are better than we had ever hoped," said Dawn's chief engineer and project manager, Marc Rayman, of NASA's Jet Propulsion Laboratory, Pasadena, California. "Dawn is like a master artist, adding rich details to the otherworldly beauty in its intimate portrait of Ceres."
The wealth of information contained in these images, and more that are planned in the coming weeks, will help address key, open questions about the origin of the faculae, the largest deposits of carbonates observed thus far outside Earth, and possibly Mars. In particular, scientists have been wondering how that material was exposed, either from a shallow, sub-surface reservoir of mineral-laden water, or from a deeper source of brines (liquid water enriched in salts) percolating upward through fractures.
And the low-altitude observations obtained with Dawn's other instruments, a gamma ray and neutron detector and a visible and infrared mapping spectrometer, will reveal the composition of Ceres at finer scale, shedding new light on the origin of the materials found across Ceres' surface. New gravity measurements also may reveal details of the subsurface.
"The first views of Ceres obtained by Dawn beckoned us with a single, blinding bright spot," said Carol Raymond of JPL, Dawn's principal investigator. "Unraveling the nature and history of this fascinating dwarf planet during the course of Dawn's extended stay at Ceres has been thrilling, and it is especially fitting that Dawn's last act will provide rich new data sets to test those theories."
See more images from Dawn's low orbits here.
Read more details about Dawn's recent orbits in Rayman's Dawn Journal.
The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. JPL is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
For a complete list of mission participants, visit:
https://dawn.jpl.nasa.gov/mission
Images can be found here.
https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA22477
Post by: jacqmans on 09/05/2018 09:31 am
MEDIA ADVISORY M18-132
NASA to Host Live Chat on Successful Mission to Asteroid Belt
NASA’s Jet Propulsion Laboratory (JPL) will host a live-streamed Science Chat at 2 p.m. EDT Friday, Sept. 7, during which experts will talk about the role of the agency’s Dawn spacecraft in studying the beginning of our solar system, and the approaching end of its 11-year mission.
The event will air live on NASA Television, Facebook Live, Ustream, YouTube and the agency's website.
Participants include:
•Jim Green, NASA chief scientist
•Carol Raymond, Dawn principal investigator at JPL
•Marc Rayman, Dawn mission director and chief engineer at JPL
Media who would like to ask questions during the event must provide their name and affiliation to Gretchen McCartney by email at [email protected] or by phone at 818-393-6215 or 818-287-4115.
The public can ask questions on Twitter using the hashtag #askNASA or in the comment section of the JPL Facebook page.
NASA launched Dawn in 2007 to learn more about the beginning of the solar system. During its mission, the spacecraft studied the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have formed early in the history of the solar system.
The mission aided scientists in characterizing the early solar system and the processes that dominated its formation. Dawn is the only spacecraft to orbit two deep-space destinations, a feat enabled by the efficiency of the spacecraft’s ion propulsion system.
For more information about Dawn, visit:
https://www.nasa.gov/dawn
Post by: Star One on 09/17/2018 10:06 pm
Quote
New observations suggest that a lonely world in the asteroid belt has been erupting frozen lava for the past billion years.
https://www.nationalgeographic.com/science/2018/09/news-ice-volcanoes-ceres-nasa-dawn-dwarf-planets-space/
Post by: zubenelgenubi on 10/08/2018 09:52 pm
NASA’s Dawn and Kepler missions near their ends (https://spacenews.com/nasas-dawn-and-kepler-missions-near-their-ends/)
Dawn and Kepler
Quote
are expected to come to an end in the coming weeks when each exhausts their remaining hydrazine fuel.
<snip>
Marc Rayman, chief engineer and mission director for the Dawn mission at the Jet Propulsion Laboratory, said current estimates had the spacecraft exhausting its remaining hydrazine, and thus ending the mission, in the middle of this month.
“To within our current uncertainty, there’s zero usable hydrazine remaining,” he said. “The hydrazine is projected to be depleted by mid-October.”
Rayman said mission planners are working on developing sequences for operating the spacecraft into December should their estimates of the remaining hydrazine turn out to be wrong. “But, you know what, we’re probably not wrong,” he said. “But we’re going to continue as long as we can.”
[Dawn] has relied on thrusters using hydrazine to orient itself since the failure of its reaction control wheels several years ago. “When the hydrazine is depleted, because that’s the sole basis for attitude control, the spacecraft will lose attitude control and the mission will end,” Rayman said.
<snip>
Rayman said planetary protection protocols require that Dawn be able to maintain its orbit, which currently brings it to within about 35 kilometers of the surface of Ceres, for at least 20 years.
That should not be a problem, he said. Simulations of the spacecraft’s orbit show a 99 percent chance it will still be in orbit after 50 years, the longest the simulations have been run. “The lifetime in orbit is likely significantly longer than that,” he said.
That 20-year requirement is not based on any expectation that the spacecraft will be sterilized from radiation exposure during that time. Instead, that 20 years is intended to provide enough time to mount another mission to the world before its surface is contaminated by the impact of the spacecraft.
“There are good arguments for revisiting such criteria,” he added, “but that’s not a topic for here.”
Post by: Star One on 10/11/2018 05:58 am
Quote
NASA’s Dawn mission has uncovered a wealth of information about the largest objects in our asteroid belt: Vesta and Ceres. Since its arrival at the latter in 2015, the spacecraft has revealed an active icy world full of surprises, one more of which has just risen to the fore: Evidence now indicates that Ceres pole has wandered by at least 36° over time, and the path it took to its present location hints at an ancient slushy ocean beneath its crust.
http://blogs.discovermagazine.com/d-brief/2018/10/10/dwarf-planet-ceres-core-and-crust-rotate-at-different-speeds/
Post by: Chris Bergin on 11/01/2018 04:51 pm
Northrop Grumman-Built Dawn Spacecraft Successfully Concludes Historic Journey
Eleven-year mission responsible for advancing our understanding of planetary formation in the solar system
DULLES, Va. – Nov. 01, 2018 – The Northrop Grumman Corporation (NYSE: NOC) today marked the successful conclusion of the company-built Dawn spacecraft’s mission to the two largest bodies in the main asteroid belt between Mars and Jupiter. The spacecraft, which has been in flight for more than 11 years, has ceased operations after depleting its attitude-control fuel. The spacecraft was the first NASA science mission to fully rely on solar electric ion propulsion, the world’s most advanced and efficient space propulsion technology.
Northrop Grumman designed and built Dawn at the company’s satellite manufacturing facility in Dulles, Virginia, working closely with the NASA Jet Propulsion Laboratory. Dawn launched from Cape Canaveral, Florida, on September 27, 2007. During its long journey, the spacecraft traveled more than 4.2 billion miles, or the equivalent of 168,000 trips around Earth’s equator. It collected and delivered an extensive amount of data, including nearly 100,000 images distributed to scientists worldwide. The mission provided the first-ever, close-up look at two planet-like bodies that date back to the formation of the solar system. The Dawn project team has received numerous prestigious awards in recognition of the mission’s achievements, including the 2014 National Air & Space Museum Trophy, the 2015 Robert J. Collier Trophy and the 2016 National Space Club’s Nelson P. Jackson Award.
“Northrop Grumman is proud to have played an important role in Dawn’s historic mission,” said Frank Culbertson, president, space systems group, Northrop Grumman. “The spacecraft has truly helped shape our knowledge of the early solar system during its 11 years in flight. It also serves as another great example of the flight-proven reliability of Northrop Grumman’s LEOStar™ spacecraft platform and the company’s dedication to delivering highly successful scientific spacecraft.”
After launch in 2007, Dawn used its ion propulsion system to direct its trajectory outward to the main asteroid belt. In February 2009, the spacecraft flew past the planet Mars, using the planet’s gravity to adjust the trajectory towards its first destination. Dawn reached Vesta, the second most massive object in the main asteroid belt, in July 2011. It spent nearly 14 months orbiting and mapping Vesta, returning more than 30,000 images and other measurements. Vesta lived up to expectations, being a dry, rocky body with a long history of massive impacts preserved in its cratered surface. In September 2012, Dawn departed Vesta in pursuit of its second destination, the dwarf planet Ceres, the largest remaining unexplored world of the inner solar system. Dawn entered orbit around Ceres in March 2015. Since then, Dawn has returned over 60,000 images of this intriguing body. The infrared spectra show evidence for past and potentially ongoing cryovolcanic activity, frozen water ice in permanently shadowed craters, and areas rich in organic material. Dawn’s images of Vesta and Ceres substantially exceed the resolution previously available, improving by more than 800 times on the resolution of Hubble Space Telescope observations.
Dawn completed its prime mission and two extended science observation missions before depleting the last of its attitude-control fuel. Engineers designed Dawn’s final orbit at Ceres to ensure it will not crash for at least 20 years -- and likely decades longer.
Post by: Chris Bergin on 11/01/2018 05:01 pm
Post by: Archibald on 11/01/2018 05:06 pm
Post by: jacqmans on 11/02/2018 07:19 am
Post by: jacqmans on 11/02/2018 07:20 am
RELEASE 18-087
NASA’s Dawn Mission to Asteroid Belt Comes to End
NASA’s Dawn spacecraft has gone silent, ending a historic mission that studied time capsules from the solar system’s earliest chapter.
Dawn missed scheduled communications sessions with NASA's Deep Space Network on Wednesday, Oct. 31, and Thursday, Nov. 1. After the flight team eliminated other possible causes for the missed communications, mission managers concluded that the spacecraft finally ran out of hydrazine, the fuel that enables the spacecraft to control its pointing. Dawn can no longer keep its antennae trained on Earth to communicate with mission control or turn its solar panels to the Sun to recharge.
The Dawn spacecraft launched 11 years ago to visit the two largest objects in the main asteroid belt. Currently, it’s in orbit around the dwarf planet Ceres, where it will remain for decades.
“Today, we celebrate the end of our Dawn mission – its incredible technical achievements, the vital science it gave us, and the entire team who enabled the spacecraft to make these discoveries,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington. “The astounding images and data that Dawn collected from Vesta and Ceres are critical to understanding the history and evolution of our solar system.”
Dawn launched in 2007 on a journey that put about 4.3 billion miles (6.9 billion kilometers) on its odometer. Propelled by ion engines, the spacecraft achieved many firsts along the way. In 2011, when Dawn arrived at Vesta, the second largest world in the main asteroid belt, the spacecraft became the first to orbit a body in the region between Mars and Jupiter. In 2015, when Dawn went into orbit around Ceres, a dwarf planet that is also the largest world in the asteroid belt, the mission became the first to visit a dwarf planet and go into orbit around two destinations beyond Earth.
"The fact that my car's license plate frame proclaims, 'My other vehicle is in the main asteroid belt,' shows how much pride I take in Dawn," said Mission Director and Chief Engineer Marc Rayman at NASA's Jet Propulsion Laboratory (JPL). "The demands we put on Dawn were tremendous, but it met the challenge every time. It's hard to say goodbye to this amazing spaceship, but it’s time."
The data Dawn beamed back to Earth from its four science experiments enabled scientists to compare two planet-like worlds that evolved very differently. Among its accomplishments, Dawn showed how important location was to the way objects in the early solar system formed and evolved. Dawn also reinforced the idea that dwarf planets could have hosted oceans over a significant part of their history – and potentially still do.
“In many ways, Dawn’s legacy is just beginning,” said Principal Investigator Carol Raymond at JPL. “Dawn’s data sets will be deeply mined by scientists working on how planets grow and differentiate, and when and where life could have formed in our solar system. Ceres and Vesta are important to the study of distant planetary systems, too, as they provide a glimpse of the conditions that may exist around young stars.”
Because Ceres has conditions of interest to scientists who study chemistry that leads to the development of life, NASA follows strict planetary protection protocols for the disposal of the Dawn spacecraft. Dawn will remain in orbit for at least 20 years, and engineers have more than 99 percent confidence the orbit will last for at least 50 years.
So, while the mission plan doesn't provide the closure of a final, fiery plunge – the way NASA’s Cassini spacecraft ended last year, for example – at least this is certain: Dawn spent every last drop of hydrazine making science observations of Ceres and radioing them back so we could learn more about the solar system we call home.
The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. JPL is responsible for overall Dawn mission science. Northrop Grumman in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
Check out the Dawn media toolkit, with a mission timeline, images, video and quick facts, at:
https://dawn.jpl.nasa.gov/mission/toolkit
Watch the video “Dawn: Mission to Small Worlds,” with NASA Chief Scientist Jim Green, at:
https://www.youtube.com/watch?v=JrafypeEhTM
More information about Dawn is available at:
https://www.nasa.gov/dawn
Post by: redliox on 11/02/2018 08:48 am
Post by: arezn on 11/06/2018 01:44 pm
Post by: worldtimedate on 11/12/2018 07:42 pm
Quote
NASA's pioneering Dawn spacecraft - which orbited the two largest objects in the asteroid belt - has run out of fuel, ending a historic 11-year mission that unravelled many mysteries of our solar system, the US space agency said. The USD 467 million Dawn mission, launched in 2007 to study the protoplanet Vesta and the dwarf planet Ceres, missed scheduled communications sessions with NASA's Deep Space Network on October 31 and November 1, NASA said in a statement.
After the flight team eliminated other possible causes for the missed communications, mission managers concluded that the spacecraft finally ran out of hydrazine, the fuel that enables the spacecraft to control its pointing. Dawn can no longer keep its antennae trained on Earth to communicate with mission control or turn its solar panels to the Sun to recharge, according to the US space agency.
Quote
In 2011, when Dawn arrived at Vesta, the second largest world in the main asteroid belt, the spacecraft became the first to orbit a body in the region between Mars and Jupiter, NASA said. In 2015, when Dawn went into orbit around Ceres, a dwarf planet that is also the largest world in the asteroid belt, the mission became the first to visit a dwarf planet and go into orbit around two destinations beyond Earth, it said.
Dawn also reinforced the idea that dwarf planets could have hosted oceans over a significant part of their history - and potentially still do. "Ceres and Vesta are important to the study of distant planetary systems, too, as they provide a glimpse of the conditions that may exist around young stars," Ms. Raymond said.
Because Ceres has conditions of interest to scientists who study chemistry that leads to the development of life, NASA follows strict planetary protection protocols for the disposal of the Dawn spacecraft, NASA said. Dawn will remain in orbit for at least 20 years, and engineers have more than 99% confidence the orbit will last for at least 50 years, it said.
Source : NASA's historic Dawn mission to asteroid belt comes to end (https://www.thehindu.com/sci-tech/science/nasas-historic-dawn-mission-to-asteroid-belt-comes-to-end/article25403872.ece)
Post by: fthomassy on 11/12/2018 09:00 pm
In a major setback to NASA's interplanetary exploration, barely less than a week two NASA Interplanetary missions have come to an abrupt end.Sure it is sad to see the missions end. However, this is in no way a setback. Kepler and Dawn, AIUI, ran out of fuel operating nominally. That is spectacular success!
Post by: Zed_Noir on 11/13/2018 07:07 pm
In a major setback to NASA's interplanetary exploration, barely less than a week two NASA Interplanetary missions have come to an abrupt end.Sure it is sad to see the missions end. However, this is in no way a setback. Kepler and Dawn, AIUI, ran out of fuel operating nominally. That is spectacular success!
IIRC both Kepler and Dawn have to expend their propellant faster than planned due to the failures of their reaction wheels. Maybe both spacecrafts could have lasted at least several more years with more durable reaction wheels.
Post by: hop on 11/13/2018 08:38 pm
IIRC both Kepler and Dawn have to expend their propellant faster than planned due to the failures of their reaction wheels. Maybe both spacecrafts could have lasted at least several more years with more durable reaction wheels.Sure, but they both greatly exceeded their nominal lifetimes (Dawn by ~2 years and Kepler by ~6) so it's really incorrect to characterize the end as some kind of setback.
Post by: speedevil on 11/13/2018 08:41 pm
Kepler was not operating nominally.In a major setback to NASA's interplanetary exploration, barely less than a week two NASA Interplanetary missions have come to an abrupt end.Sure it is sad to see the missions end. However, this is in no way a setback. Kepler and Dawn, AIUI, ran out of fuel operating nominally. That is spectacular success!
Kepler had a failed gyro, and was doing different, but also useful science than it once did.
If it had been able to continue staring at the nominal field, it would have been able to come closer to performing its main mission.
That of discovering earth-like planets around sun-like stars in earth-like orbits. (It has not quite done this, it has found earth analogs around smaller dimmer stars on faster orbits, with similar temperatures and masses to earth)
It would have (if the reaction wheels had not failed, and it continued to be pointed in the same direction) been able to detect planets around target stars with a radius of approximately 70%, and a mass of 50% what it in fact did discover.
It would have determined orbits for planets with >4 year orbits, which at the moment are unresolved single transits.
The data collected by the ongoing mission since the gyro failure in 2013 has been interesting and valuable - however continuing staring at the same bit of sky for at least a few years longer would have been valuable.
Post by: Alpha_Centauri on 11/13/2018 09:10 pm
Of course i'd love it if they carried on taking data after that with no technical issues but that is an entirely unrealistic expectation.
Post by: speedevil on 11/13/2018 09:25 pm
Spacecraft are supposed to last the duration of their primary mission, everything else is a bonus.
They are supposed to last long enough to perform their primary mission - due to mission specification problems, the primary mission duration was not long enough to achieve this.
An extended mission would have come a lot closer.
(the variability of sun-like stars was not well known, and was assumed to be like the sun, when in fact it was considerably noisier)
Post by: Chris Bergin on 11/23/2018 05:23 pm
https://www.nasaspaceflight.com/2018/11/dawn-intrepid-explorer-multiple-worlds/ …
As we prepare for NASA's Mars InSight's big day, we look back at the work of the recently concluded Dawn mission.
- By Justin Davenport
https://twitter.com/NASASpaceflight/status/1066034350943285248
Post by: Star One on 12/10/2018 09:00 pm
Quote
A team led by Southwest Research Institute has concluded that the surface of dwarf planet Ceres is rich in organic matter. Data from NASA's Dawn spacecraft indicate that Ceres's surface may contain several times the concentration of carbon than is present in the most carbon-rich, primitive meteorites found on Earth.
"Ceres is like a chemical factory," said SwRI's Dr. Simone Marchi, a principal scientist who was the lead author of research published in Nature Astronomy today. "Among inner solar system bodies, Ceres' has a unique mineralogy, which appears to contain up to 20 percent carbon by mass in its near surface. Our analysis shows that carbon-rich compounds are intimately mixed with products of rock-water interactions, such as clays."
Post by: Star One on 06/17/2019 05:12 pm
Quote
This is an oblong mountain sticking out of the side of the protoplanet, 17 km across at its base and stretching over 4 kilometers high into the airless sky. It’s flat-topped, like a mesa, with long angled flanks surrounding it like a skirt. There’s nothing else like it on Ceres, and with the exception of a single adjacent crater, the terrain around it is relatively flat and devoid of any structures. Ahuna Mons literally stands alone.
And that’s weird. Ceres has no tectonic activity, so it can’t grow mountains that way. That usually forms mountain chains, anyway (like the continental plate collisions on Earth that created the Rocky Mountains and the Himalayas).
That only leaves one other explanation: Upwelling. Literally something under the surface trying its best to get out.
Post by: FutureSpaceTourist on 07/29/2019 09:51 am
Quote
Ahuna Mons on Ceres
This image, based on observations from NASA’s Dawn spacecraft, shows the largest mountain on the dwarf planet Ceres.
Dawn was the first mission to orbit an object in the asteroid belt between Mars and Jupiter, and spent time at both large asteroid Vesta and dwarf planet Ceres. Ceres is one of just five recognised dwarf planets in the Solar System (Pluto being another). Dawn entered orbit around this rocky world on 6 March 2015, and studied its icy, cratered, uneven surface until it ran out of fuel in October of 2018.
One of the features spotted by the mission is shown here in this reconstructed perspective view: a mountain named Ahuna Mons. This mountain rises to an elevation of 4000 m at its peak – Europe’s Mont Blanc on Earth would rise slightly above it (as measured from sea level) – and is marked by numerous bright streaks that run down its flanks. Scientists have determined that these marks are actually salt deposits left behind from the formation of Ahuna Mons, when plumes of saltwater and mud rose and erupted from within Ceres, puncturing the surface and creating the mountain seen here. While temperatures on Ceres are far colder than those on Earth, this mechanism is thought to be somewhat similar to the formation of volcanoes by terrestrial magma plumes.
More recently, a study of Dawn data led by ESA research fellow Ottaviano Ruesch and Antonio Genova (Sapienza Università di Roma), published in Nature Geoscience in June, suggests that a briny, muddy ‘slurry’ exists below Ceres’ surface, surging upwards towards and through the crust to create Ahuna Mons. Another recent study, led by Javier Ruiz of Universidad Complutense de Madrid and published in Nature Astronomy in July, also indicates that the dwarf planet has a surprisingly dynamic geology.
Ceres was also the focus of an earlier study by ESA’s Herschel space observatory, which detected water vapour around the dwarf planet. Published in Nature in 2014, the result provided a strong indication that Ceres has ice on or near its surface. Dawn confirmed Ceres’ icy crust via direct observation in 2016, however, the contribution of the ice deposits to Ceres’ exosphere turned out to be much lower than that inferred from the Herschel observations.
The perspective view depicted in this image uses enhanced-colour combined images taken using blue (440 nm), green (750 nm), and infrared (960 nm) filters, with a resolution of 35 m/pixel. Ahuna Mons’ elevation has been exaggerated by a factor of two. The width of the dome is approximately 20 km. The spacecraft’s Framing Camera took the images from Dawn’s low-altitude mapping orbit from an altitude of 385 km in August 2016.
Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
https://www.flickr.com/photos/europeanspaceagency/48402671921/
Post by: Star One on 08/11/2020 06:57 pm
https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA24021
Post by: Star One on 10/19/2023 04:25 pm
Quote
Considering the significant organic material on Ceres, combined with indications of its substantial water ice content, experts believe that the planet might have the essential elements to foster life beyond Earth.
“Although researchers have performed impact and shock experiments on various types of organics in the past, what was missing was a study dedicated to the type of organics detected on Ceres using the same type of analytical method used by the Dawn spacecraft to detect them,” Daly said, emphasizing the value of comparative analysis of the organic data derived from the dwarf planet.
https://www.earth.com/news/dwarf-planet-ceres-could-potentially-sustain-life/