Author Topic: NASA - Cassini updates  (Read 279268 times)

Offline catdlr

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Re: NASA - Cassini updates
« Reply #480 on: 09/24/2016 02:10 am »
Charm Cassini Huygens Mission to Saturn 12th Anniversary

NASASolarSystem

Published on Sep 23, 2016
This is the first half of the annual CHARM anniversary telecon, in which we review the science highlights from Cassiniís various disciplines. We are pleased to invite you to join us to hear Dr. Elizabeth (Zibi) Turtle of the Johns Hopkins University Applied Physics Lab and the Cassini ISS team who will be speaking about Saturnís largest moon, Titan and Dr. Ali Sulaiman of the University of Iowa who will be speaking about Cassiniís recent discoveries about Saturnís magnetosphere.


https://www.youtube.com/watch?v=9crC3HJswFI?t=001

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Offline catdlr

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Re: NASA - Cassini updates
« Reply #481 on: 09/29/2016 03:05 am »
Revealing Saturn: Cassini Science Highlights and the Grand Finale

NASASolarSystem

Published on Sep 28, 2016
Cassini mission leads Earl Maize and Linda Spilker talked about the spacecraft's epic journey and science - and the exciting two-part grand finale.

Program starts at 2:30 into the following video.

https://www.youtube.com/watch?v=DD-dK5vPBkY?t=001

Tony De La Rosa

Offline savuporo

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Re: NASA - Cassini updates
« Reply #482 on: 09/29/2016 05:51 am »
Cassini mission leads Earl Maize and Linda Spilker talked about the spacecraft's epic journey and science - and the exciting two-part grand finale.
Excellent presentation, and some inspiring questions at the end !
Orion - the first and only manned not-too-deep-space craft

Online eeergo

Re: NASA - Cassini updates
« Reply #483 on: 09/30/2016 03:13 am »
Cassini mission leads Earl Maize and Linda Spilker talked about the spacecraft's epic journey and science - and the exciting two-part grand finale.
Excellent presentation, and some inspiring questions at the end !

I'll second that, really informative and well-explained, and great to see the questioners being so excited about the explanations. It's a pleasure to listen to these extraordinary professionals explain even the most broad and well-publicized discoveries from Cassini, and details about what we can expect starting in a month's time.
-DaviD-

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Re: NASA - Cassini updates
« Reply #484 on: 09/30/2016 03:53 am »
Not related to the above, but amazing "belly-button" south polar vortex storm, clearly higher than the surrounding upper haze layers.
« Last Edit: 09/30/2016 03:54 am by eeergo »
-DaviD-

Offline Star One

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Re: NASA - Cassini updates
« Reply #485 on: 10/04/2016 08:05 pm »

Offline Star One

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Re: NASA - Cassini updates
« Reply #486 on: 10/31/2016 08:02 pm »

Offline catdlr

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Re: NASA - Cassini updates
« Reply #487 on: 11/04/2016 02:31 am »
Four Days at Saturn

NASASolarSystem

Published on Nov 3, 2016
NASA's Cassini spacecraft stared at Saturn for nearly 44 hours on April 25≠ to 27, 2016, to obtain this movie showing just over four Saturn days.

With Cassini's orbit being moved closer to the planet in preparation for the mission's 2017 finale, scientists took this final opportunity to capture a long movie in which the planet's full disk fit into a single wide-angle camera frame.

Visible at top is the giant hexagon-shaped jet stream that surrounds the planet's north pole. Each side of this huge shape is slightly wider than Earth.

The resolution of the 250 natural color wide-angle camera fames comprising this movie is 512 by 512 pixels, rather than the camera's full resolution of 1024 by 1024 pixels. Cassini's imaging cameras have the ability to take reduced-size images like these in order to decrease the amount of data storage space required for an observation.

The spacecraft began acquiring this sequence of images just after it obtained the images to make a three-panel color mosaic (see Saturn, Approaching Northern Summer​ ).

When it began taking images for this movie sequence, Cassini was 1,847,000 miles (2,973,000 kilometers) from Saturn, with an image scale of 355 kilometers per pixel. When it finished gathering the images, the spacecraft had moved 171,000 miles (275,000 kilometers) closer to the planet, with an image scale of 200 miles (322 kilometers) per pixel.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini.

Download this video: https://saturn.jpl.nasa.gov/resources/7502/

Credit
NASA/JPL-Caltech/Space Science Institute

https://www.youtube.com/watch?v=GTYKmxlbtio?t=001

Tony De La Rosa

Offline catdlr

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Re: NASA - Cassini updates
« Reply #488 on: 11/04/2016 02:33 am »
Mixed Signals From Saturn

NASASolarSystem

Published on Nov 3, 2016
Saturn is sending out mixed signals in recent data from NASA's Cassini spacecraft and the NASA/ESA Hubble Space Telescope.

Transcript:

Marcia Burton: Saturn is sending us mixed signals. Mixed radio signals, that is.

I'm Marcia Burton, Cassini fields and particles scientist, at NASA's Jet Propulsion Lab.

Cassini has been in orbit around Saturn for more than six years. And new data tells scientists
that the sixth planet from the sun is weirder than we've even imagined.

Ever since we arrived, Cassini has been measuring radio waves called 'Saturn kilometric radiation.'

Cassini's radio and plasma wave instrument recently determined that the variation in radio waves
is different in the northern and southern hemispheres of Saturn.

And the northern and southern rotational variations also appear to change with the Saturnian seasons.

Sound: Radio waves

Burton: The radio wave patterns are controlled by the rotation of the planet
So, to Cassini, Saturn's radio waves sound a bit like bursts of a spinning air raid siren.

Sound: Radio waves

Burton: We can't normally hear these radio wave patterns. But Cassini scientists
have translated the patterns into the human audio range.

In this video you actually hear the radio wave patterns coming from the two hemispheres
swap rates over the course of several years.

The crossover happened a few months after spring began in the northern hemisphere.

Scientists don't think the radio wave patterns indicate hemispheres actually rotating at different rates.

It has more to do with variations in high-altitude winds.

A recently result from the Hubble Space Telescope also gives us clues.

Scientists found that the northern and southern auroras wobbled back and forth
in a pattern matching the radio wave variations.

The Cassini magnetometer also found that Saturn's magnetic field over the north and south poles
wobbled in a similar pattern.

These signals are connected because they're all affected by the behavior of the magnetic bubble around Saturn
and the sun's influence on the whole Saturnian system.

For those of us watching Saturn, these findings all help explain the complicated dance between the sun and
Saturn's magnetic bubble, something normally invisible to the human eye and imperceptible to the human ear.

Sound: Radio waves

https://www.youtube.com/watch?v=4JN7Sk9cTQA?t=001

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Offline catdlr

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Re: NASA - Cassini updates
« Reply #489 on: 11/04/2016 02:36 am »
Cassini CHARM: Titan Cold Case Files

NASASolarSystem

Published on Nov 3, 2016
Hear about what we know about Titan topics that were investigated early in Cassiniís mission. Learn what questions have baffled and perplexed Cassini scientists for a long while (cough cough cryovolcanism cough cough).

https://www.youtube.com/watch?v=VSFtw2zJKuM?t=001

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Offline catdlr

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Re: NASA - Cassini updates
« Reply #490 on: 11/04/2016 10:55 pm »
Summer Clouds on Saturn's Moon Titan

NASA Jet Propulsion Laboratory

Published on Nov 4, 2016
NASA's Cassini spacecraft watched clouds of methane moving across the far northern regions of Saturn's largest moon, Titan, on Oct. 29≠≠≠≠ and 30, 2016. Read more at http://go.nasa.gov/2fnVoBw

Saturn orbits the sun much farther than Earth, at a distance of about 888 million miles (1.4 million kilometers).

https://www.youtube.com/watch?v=0seT55Jk4Ko?t=001

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Offline catdlr

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Re: NASA - Cassini updates
« Reply #491 on: 11/23/2016 01:45 am »
NASA Saturn Mission Prepares for 'Ring-Grazing Orbits'

First Phase in Dramatic Endgame for Long-Lived Cassini Spacecraft

A thrilling ride is about to begin for NASA's Cassini spacecraft. Engineers have been pumping up the spacecraft's orbit around Saturn this year to increase its tilt with respect to the planet's equator and rings. And on Nov. 30, following a gravitational nudge from Saturn's moon Titan, Cassini will enter the first phase of the mission's dramatic endgame.

Launched in 1997, Cassini has been touring the Saturn system since arriving there in 2004 for an up-close study of the planet, its rings and moons. During its journey, Cassini has made numerous dramatic discoveries, including a global ocean within Enceladus and liquid methane seas on Titan.

Between Nov. 30 and April 22, Cassini will circle high over and under the poles of Saturn, diving every seven days -- a total of 20 times -- through the unexplored region at the outer edge of the main rings.

"We're calling this phase of the mission Cassini's Ring-Grazing Orbits, because we'll be skimming past the outer edge of the rings," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. "In addition, we have two instruments that can sample particles and gases as we cross the ringplane, so in a sense Cassini is also 'grazing' on the rings."

On many of these passes, Cassini's instruments will attempt to directly sample ring particles and molecules of faint gases that are found close to the rings. During the first two orbits, the spacecraft will pass directly through an extremely faint ring produced by tiny meteors striking the two small moons Janus and Epimetheus. Ring crossings in March and April will send the spacecraft through the dusty outer reaches of the F ring.

"Even though we're flying closer to the F ring than we ever have, we'll still be more than 4,850 miles (7,800 kilometers) distant. There's very little concern over dust hazard at that range," said Earl Maize, Cassini project manager at JPL.

The F ring marks the outer boundary of the main ring system; Saturn has several other, much fainter rings that lie farther from the planet. The F ring is complex and constantly changing: Cassini images have shown structures like bright streamers, wispy filaments and dark channels that appear and develop over mere hours. The ring is also quite narrow -- only about 500 miles (800 kilometers) wide. At its core is a denser region about 30 miles (50 kilometers) wide.

So Many Sights to See

Cassini's ring-grazing orbits offer unprecedented opportunities to observe the menagerie of small moons that orbit in or near the edges of the rings, including best-ever looks at the moons Pandora, Atlas, Pan and Daphnis.

Grazing the edges of the rings also will provide some of the closest-ever studies of the outer portions of Saturn's main rings (the A, B and F rings). Some of Cassini's views will have a level of detail not seen since the spacecraft glided just above them during its arrival in 2004. The mission will begin imaging the rings in December along their entire width, resolving details smaller than 0.6 mile (1 kilometer) per pixel and building up Cassini's highest-quality complete scan of the rings' intricate structure.

The mission will continue investigating small-scale features in the A ring called "propellers," which reveal the presence of unseen moonlets. Because of their airplane propeller-like shapes, scientists have given some of the more persistent features informal names inspired by famous aviators, including "Earhart." Observing propellers at high resolution will likely reveal new details about their origin and structure.

And in March, while coasting through Saturn's shadow, Cassini will observe the rings backlit by the sun, in the hope of catching clouds of dust ejected by meteor impacts.

Preparing for the Finale

During these orbits, Cassini will pass as close as about 56,000 miles (90,000 kilometers) above Saturn's cloud tops. But even with all their exciting science, these orbits are merely a prelude to the planet-grazing passes that lie ahead. In April 2017, the spacecraft will begin its Grand Finale phase.

After nearly 20 years in space, the mission is drawing near its end because the spacecraft is running low on fuel. The Cassini team carefully designed the finale to conduct an extraordinary science investigation before sending the spacecraft into Saturn to protect its potentially habitable moons.

During its grand finale, Cassini will pass as close as 1,012 miles (1,628 kilometers) above the clouds as it dives repeatedly through the narrow gap between Saturn and its rings, before making its mission-ending plunge into the planet's atmosphere on Sept. 15. But before the spacecraft can leap over the rings to begin its finale, some preparatory work remains.

To begin with, Cassini is scheduled to perform a brief burn of its main engine during the first super-close approach to the rings on Dec. 4. This maneuver is important for fine-tuning the orbit and setting the correct course to enable the remainder of the mission.

"This will be the 183rd and last currently planned firing of our main engine. Although we could still decide to use the engine again, the plan is to complete the remaining maneuvers using thrusters," said Maize.

To further prepare, Cassini will observe Saturn's atmosphere during the ring-grazing phase of the mission to more precisely determine how far it extends above the planet. Scientists have observed Saturn's outermost atmosphere to expand and contract slightly with the seasons since Cassini's arrival. Given this variability, the forthcoming data will be important for helping mission engineers determine how close they can safely fly the spacecraft.

For details about Cassini's Ring-Grazing Orbits, including timing, closest approach distances and highlights, visit:

https://saturn.jpl.nasa.gov/news/2966/ring-grazing-orbits

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter.

More information about Cassini:

http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov



Saturn's rings were named alphabetically in the order they were discovered. The narrow F ring marks the outer boundary of the main ring system. Image credit: NASA/JPL-Caltech/Space Science Institute
« Last Edit: 11/23/2016 01:46 am by catdlr »
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Offline catdlr

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Re: NASA - Cassini updates
« Reply #492 on: 12/06/2016 11:54 pm »
Cassini Beams Back First Images from New Orbit

http://www.jpl.nasa.gov/news/news.php?feature=6693

Quote
NASA's Cassini spacecraft has sent to Earth its first views of Saturn's atmosphere since beginning the latest phase of its mission. The new images show scenes from high above Saturn's northern hemisphere, including the planet's intriguing hexagon-shaped jet stream.

Photo Info:
This view from NASA's Cassini spacecraft was obtained about half a day before its first close pass by the outer edges of Saturn's main rings during its penultimate mission phase.

The view shows part of the giant, hexagon-shaped jet stream around the planet's north pole. Each side of the hexagon is about as wide as Earth. A circular storm lies at the center, at the pole (see PIA14944).

The image was taken with the Cassini spacecraft wide-angle camera on Dec. 3, 2016, at a distance of about 240,000 miles (390,000 kilometers) from Saturn. Image scale is 14 miles (23 kilometers) per pixel.
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Re: NASA - Cassini updates
« Reply #493 on: 01/31/2017 10:19 am »
Extraordinary close-up images (~500m resolution) of the rings in this new update:


https://saturn.jpl.nasa.gov/news/2993/close-views-show-saturns-rings-in-unprecedented-detail/


Remarkable are features like aggregations of ring particles around clumps and embedded moonlets, as well as gravity/density waves propagating on the rings like ripples in a water pond.
-DaviD-

Offline Star One

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Re: NASA - Cassini updates
« Reply #494 on: 02/06/2017 07:25 pm »
Potentially Hospitable Enceladus

Quote
Seen from outside, Enceladus appears to be like most of its sibling moons: cold, icy and inhospitable. But under that forbidding exterior may exist the very conditions needed for life.

Over the course of the Cassini mission, observations have shown that Enceladus (313 miles or 504 kilometers across) not only has watery jets sending icy grains into space; under its icy crust it also has a global ocean, and may have hydrothermal activity as well. Since scientists believe liquid water is a key ingredient for life, the implications for future missions searching for life elsewhere in our solar system could be significant.

This view looks toward the Saturn-facing hemisphere of Enceladus. North on Enceladus is up and rotated 6 degrees to the right. The image was taken in green light with the Cassini spacecraft narrow-angle camera on Nov. 27, 2016.

The view was obtained at a distance of approximately 81,000 miles (130,000 kilometers) from Enceladus. Image scale is 2,566 feet (782 meters) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA20522
« Last Edit: 02/06/2017 07:26 pm by Star One »

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Re: NASA - Cassini updates
« Reply #495 on: 03/09/2017 07:32 pm »
Here's Our Best Look Yet at Saturn's 'UFO' Moon

Adorned with a thin band of icy ring particles, the small moon Pan inspires comparisons to alien spacecraft, walnuts, and even ravioli.

http://news.nationalgeographic.com/2017/03/saturn-ufo-moon-pan-nasa-cassini-space-science/#close

Offline Ben the Space Brit

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Re: NASA - Cassini updates
« Reply #496 on: 03/10/2017 09:05 am »
Here's what I'm thinking: Pan is a merged object. Two slushy (high liquid component to solid component ratio) and low-density objects collide at very low relative speed. You don't get a shattering effect, rather they merge with the two contact faces being squashed out of the sides into the ring-shaped feature like two lumps of soft dough pressed together.

IMO, it is something that should be almost expected for the Saturnian rings.
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Re: NASA - Cassini updates
« Reply #497 on: 03/10/2017 09:19 am »
Here's what I'm thinking: Pan is a merged object. Two slushy (high liquid component to solid component ratio) and low-density objects collide at very low relative speed. You don't get a shattering effect, rather they merge with the two contact faces being squashed out of the sides into the ring-shaped feature like two lumps of soft dough pressed together.

IMO, it is something that should be almost expected for the Saturnian rings.

I don't think that's right. The explanation from Carolyn Porco is apparently accretion onto the equator as Pan was clearing its ring gap ...

Links to two papers here:
https://twitter.com/carolynporco/status/839869932426809344

--- Tony

Offline Star One

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Re: NASA - Cassini updates
« Reply #498 on: 03/10/2017 10:53 am »
Here's what I'm thinking: Pan is a merged object. Two slushy (high liquid component to solid component ratio) and low-density objects collide at very low relative speed. You don't get a shattering effect, rather they merge with the two contact faces being squashed out of the sides into the ring-shaped feature like two lumps of soft dough pressed together.

IMO, it is something that should be almost expected for the Saturnian rings.

I don't think that's right. The explanation from Carolyn Porco is apparently accretion onto the equator as Pan was clearing its ring gap ...

Links to two papers here:
https://twitter.com/carolynporco/status/839869932426809344

--- Tony

Especially as another of its moons Atlas has exactly the same accretion.
« Last Edit: 03/10/2017 10:54 am by Star One »

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Re: NASA - Cassini updates
« Reply #499 on: 03/10/2017 05:03 pm »
Here's what I'm thinking: Pan is a merged object. Two slushy (high liquid component to solid component ratio) and low-density objects collide at very low relative speed. You don't get a shattering effect, rather they merge with the two contact faces being squashed out of the sides into the ring-shaped feature like two lumps of soft dough pressed together.

IMO, it is something that should be almost expected for the Saturnian rings.

I don't think that's right. The explanation from Carolyn Porco is apparently accretion onto the equator as Pan was clearing its ring gap ...

Links to two papers here:
https://twitter.com/carolynporco/status/839869932426809344

--- Tony

Especially as another of its moons Atlas has exactly the same accretion.

Exactly.  It looks like a big rock with a pile of fine sand around it.  Imagine coring through that and discovering a history of Saturn's rings.
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