Author Topic: New Horizons Pluto Flyby Coverage  (Read 253329 times)

Offline Eerie

  • Member
  • Full Member
  • ****
  • Posts: 754
  • Liked: 111
  • Likes Given: 7
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #40 on: 02/05/2015 08:09 PM »
Sadly this isn't a real-life mission, but it is an extremely cool concept.  I had no idea until watching that how truly far away Eris is.

I doubt Eris will get any immediate visits for a long while.  Regarding the video, a very nice fly-by vehicle.  I certainly would like to see something like that sent to either Uranus or Neptune, more specifically the later since there's a vague chance Uranus might get a full fledged orbiter in the next two decades.

Ugh, 2051? Can't we just use a bigger rocket?

Offline Blackstar

  • Veteran
  • Senior Member
  • *****
  • Posts: 10990
  • Liked: 2457
  • Likes Given: 1
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #41 on: 02/05/2015 08:09 PM »
I doubt Eris will get any immediate visits for a long while.  Regarding the video, a very nice fly-by vehicle.  I certainly would like to see something like that sent to either Uranus or Neptune, more specifically the later since there's a vague chance Uranus might get a full fledged orbiter in the next two decades.

My hope is that the Pluto encounter is sufficiently fascinating to add weight to the argument that we need closer study of Triton (probably the only KBO that we can realistically study in any detail). It's a weak daydream, I know, but a boy can still dream, right?

Keep in mind that Uranus was only in the decadal survey because Neptune is not an option this time due to location/trajectories. Neptune and Uranus rank equally in terms of scientific interest. I think Uranus edges out Neptune because it is closer, but ice giant scientists could flip a coin and take either one.

Offline Blackstar

  • Veteran
  • Senior Member
  • *****
  • Posts: 10990
  • Liked: 2457
  • Likes Given: 1
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #42 on: 02/05/2015 08:11 PM »
Anybody living in the Houston area might be interested in this free talk.

Offline redliox

  • Full Member
  • ****
  • Posts: 1726
  • Arizona USA
  • Liked: 323
  • Likes Given: 54
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #43 on: 02/05/2015 08:29 PM »
My hope is that the Pluto encounter is sufficiently fascinating to add weight to the argument that we need closer study of Triton (probably the only KBO that we can realistically study in any detail). It's a weak daydream, I know, but a boy can still dream, right?

Keep in mind that Uranus was only in the decadal survey because Neptune is not an option this time due to location/trajectories. Neptune and Uranus rank equally in terms of scientific interest. I think Uranus edges out Neptune because it is closer, but ice giant scientists could flip a coin and take either one.

Hypothetically advances in ion drive could make either eligible for a new flyby with or without Jupiter/Saturn assisting.  But yeah, Uranus' proximity allows the orbiter option whereas Neptune is beyond that.  All the same, I'd push for a revisit to Neptune and maximize the encounter with an atmosphere probe - that was a strong option in the various studies done.

Regarding New Horizons and KBOs, hopefully it visits the larger of the 3 discovered targets; I suspect the smaller asteroid-sized variety of KBOs are more prevalent than Triotn/Pluto/Eris sizes.
"Let the trails lead where they may, I will follow."
-Tigatron

Offline AS_501

  • Full Member
  • *
  • Posts: 117
  • Pittsburgh, PA
  • Liked: 34
  • Likes Given: 0
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #44 on: 02/05/2015 09:07 PM »
I'm no planetary scientist, but isn't it puzzling that little Pluto attracted so many satellites, and perhaps smaller debris that may be hazardous to New Horizons?  Normally only a rocky/iron-rich body (like Mercury) could create such a strong gravity well.  Presumably the deflection of New Horizon's trajectory by Pluto will suggest something about its density and internal structure.  I'm interested in any other theories as to why Pluto is so "attractive".

Online John-H

  • Full Member
  • *
  • Posts: 126
  • Liked: 31
  • Likes Given: 78
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #45 on: 02/05/2015 11:56 PM »
Is it possible that there is a lot more "stuff" out there than we realize?  We can't see any smaller bodies, so our normal models are based on them not being there at all.

Does New Horizons have a mode where it can search for new small bodies near it's path?

John

Offline Cinder

  • Full Member
  • ****
  • Posts: 562
  • Liked: 51
  • Likes Given: 189
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #46 on: 02/06/2015 02:40 AM »
http://arstechnica.com/science/2015/01/the-solar-system-may-have-two-undiscovered-planets/

Quote
Given the huge number of exoplanets discovered in recent years, the discovery of two new planets would come as no surprise—except that these two, discussed in a new study, may be part of our Solar System.

The presence of the closer of the two planets had already been suggested in a previous work. The new study provides more evidence for its existence and adds a second planet. Both studies are based on observations of objects far beyond Neptune’s orbit, called extreme trans-Neptunian objects (ETNOs). These ETNOs display shared patterns in their orbits, which suggests they’re all being influenced gravitationally by heavier objects, much further away from the Sun.

While this conclusion is based on a small sample (13 bodies), the authors confirm that their results are statistically significant and that at least two planets, orbiting far beyond Pluto’s orbit, are the most likely explanation for the observations.
The pork must flow.

Online hop

  • Senior Member
  • *****
  • Posts: 3234
  • Liked: 388
  • Likes Given: 734
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #47 on: 02/06/2015 02:53 AM »
We can't see any smaller bodies, so our normal models are based on them not being there at all.
Not really, the default model is some distribution that blends into the the size range we can observe. There are some constraints too, for example from the size distribution of periodic comets.
Quote
Does New Horizons have a mode where it can search for new small bodies near it's path?
No, New Horizons instruments are not at all suitable for that kind of thing. Space is big, even if there were thousands of times more sub-km bodies than we expect, NH would have essentially no chance of noticing them.

Unless you mean *really* small objects... NH does have a dust detector ;)

Online Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 6997
  • A spaceflight fan
  • London, UK
  • Liked: 553
  • Likes Given: 638
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #48 on: 02/06/2015 01:41 PM »
Barring an insisted-upon expedition to Eris

We have one of those launching in November, actually. ;)

Just out of interest, did you calculate how long it would take the probe to reach the heliosheath - the eletromagnetic edge of the solar system?
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline Sesquipedalian

  • Whee!
  • Full Member
  • ****
  • Posts: 630
  • Liked: 178
  • Likes Given: 513
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #49 on: 02/06/2015 02:29 PM »
Just out of interest, did you calculate how long it would take the probe to reach the heliosheath - the eletromagnetic edge of the solar system?

No, I haven't calculated that, though I'd be interested in the answer.  I had nothing to do with the making of that YouTube video. :)

Offline kato

  • Member
  • Posts: 94
  • Liked: 19
  • Likes Given: 14
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #50 on: 02/09/2015 08:55 AM »
At 3.0 AU per year outbound velocity and anywhere from 50 to 70 AU to go depending on how the sheath is aligned in that area? Sometime between 2031 and 2041, roundabout.

Offline mikelepage

http://arstechnica.com/science/2015/01/the-solar-system-may-have-two-undiscovered-planets/

Quote
Given the huge number of exoplanets discovered in recent years, the discovery of two new planets would come as no surprise—except that these two, discussed in a new study, may be part of our Solar System.

The presence of the closer of the two planets had already been suggested in a previous work. The new study provides more evidence for its existence and adds a second planet. Both studies are based on observations of objects far beyond Neptune’s orbit, called extreme trans-Neptunian objects (ETNOs). These ETNOs display shared patterns in their orbits, which suggests they’re all being influenced gravitationally by heavier objects, much further away from the Sun.

While this conclusion is based on a small sample (13 bodies), the authors confirm that their results are statistically significant and that at least two planets, orbiting far beyond Pluto’s orbit, are the most likely explanation for the observations.

EDIT: Well I think I have just answered my own questions, but I found the exercise interesting, so here's my work.

Supposing that one of these planets was reachable on New Horzions' trajectory (yes, I know, it's extremely unlikely), I first wondered if NH might be able to do some work upon arrival.  At 2.5-3AU/year, I believe that would put NH in the vicinity of the 200AU planet by 2069 and the 250AU planet by 2081-ish.  A brief search on google suggests that the NH RTG runs low on power output by 2030, so doing any science with NH once there is a non-starter. 

My second question came from thinking about the Hubble campaign to find targets for NH in the space beyond the Pluto-Charon system.  Given that Hubble searched pretty thoroughly in that area, would we expect to have seen them if one of those planets if it was in that field of view? Or would you need to use Spitzer (IR telescope)? Or do we even have a telescope that could do it.

My working: supposing that the closer planet was the super-Earth they speak of (eg. 5 Earth masses).  If similar density to Earth, diameter would be 21,800km (as opposed to ~12,700km for Earth, or 2,300km for Pluto).  At 200 AU this is an angle of 2.58 arc minutes (well within Hubble's resolving power of 0.05 arc seconds).  So it would be 9x the size of Pluto, 5-6.25x as far away, but(!) with 1/25-1/39th the solar illumination. 

Basically, for something to be as visible as Pluto is at that distance, I figure it should be 25x the area (if at 200AU) or 39x the area (if at 250AU) of Pluto.  The disk of a 5x super Earth would be 9.5x the area.  Earth itself would only be 5x the area, so these would probably be single pixel objects (the best Hubble images of Pluto are only a few pixels across).   Having said that, since it doesn't have to be as anywhere near as bright as Pluto to be detectable, I think it's safe to say that Hubble should be able to image these planets (and would have seen them if they were in the NH study search field), but it would have to know *exactly* where to look to even have a chance of spotting them.


Offline kato

  • Member
  • Posts: 94
  • Liked: 19
  • Likes Given: 14
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #52 on: 02/09/2015 03:24 PM »
Given that Hubble searched pretty thoroughly in that area, would we expect to have seen them if one of those planets if it was in that field of view? Or would you need to use Spitzer (IR telescope)? Or do we even have a telescope that could do it.
If there was something out there, we'd already have it somewhere in the IRSA archive's all-sky catalogues.

Offline Star One

  • Senior Member
  • *****
  • Posts: 8265
  • UK
  • Liked: 1339
  • Likes Given: 168
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #53 on: 02/09/2015 06:54 PM »

Given that Hubble searched pretty thoroughly in that area, would we expect to have seen them if one of those planets if it was in that field of view? Or would you need to use Spitzer (IR telescope)? Or do we even have a telescope that could do it.
If there was something out there, we'd already have it somewhere in the IRSA archive's all-sky catalogues.

You comment needs qualification as what you say is true for larger Jupiter sized planets, however, it is not true of smaller Earth sized or below.

Offline Cinder

  • Full Member
  • ****
  • Posts: 562
  • Liked: 51
  • Likes Given: 189
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #54 on: 02/09/2015 08:47 PM »
Maybe he meant that it would have been captured, but not noticed.
The pork must flow.

Offline mikelepage

Maybe he meant that it would have been captured, but not noticed.

At that distance, those planets might be moving so slowly against the background that they wouldn't trigger the threshold for "moving object".

Offline kato

  • Member
  • Posts: 94
  • Liked: 19
  • Likes Given: 14
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #56 on: 02/10/2015 03:41 PM »
There have been evaluations of the IRSA data for largescale planets far farther out (which didn't find any - for Jupiter-size out to somewhere around 15-20,000 AU iirc). That's why the planet(s) hypothesized for 200/250 AU were tailored in exactly such a way (very cold and very low albedo) as to come within the limits that previous searches in IRSA would have found.

Basically, one would have to fine-comb the database again with lower limits, which probably also means more false positives. Having Gaia's couple hundred terabytes of data will probably also help in a couple years, just about in time for JWST to examine anything found in the data...

Offline Blackstar

  • Veteran
  • Senior Member
  • *****
  • Posts: 10990
  • Liked: 2457
  • Likes Given: 1
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #57 on: 02/22/2015 05:29 PM »
The view from Hydra, by Ron Miller.

Offline redliox

  • Full Member
  • ****
  • Posts: 1726
  • Arizona USA
  • Liked: 323
  • Likes Given: 54
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #58 on: 02/22/2015 08:03 PM »
From the encounter geometry, it appears Nix and Charon will be the best imaged satellites - the other three small satellites sadly are going to be at their far points from New Horizons.

It is interesting to know even the smallest moons are easily a match for Mars' Phobos, so they will have something to show for themselves even with Charon and Pluto dominating the limelight.
"Let the trails lead where they may, I will follow."
-Tigatron

Offline eeergo

  • Phystronaut
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 4769
  • Milan, Italy; Spain; Virginia
  • Liked: 435
  • Likes Given: 356
Re: New Horizons begins Pluto observations ahead of July flyby
« Reply #59 on: 03/10/2015 10:16 AM »
Quote from: NewHorizons2015
Just 1 hour ago NH made its 1st homing burn to target Pluto. News is speeding to Earth @ the speed of light, arrival ~11:45 Eastern Time.
-DaviD-

Tags: New Horizons