Cassini Equinox & Solstice Mission, (nine year extension)!!.

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EarthlingX

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3488":1cj60tfa said:
EarthlingX":1cj60tfa said:
3488":1cj60tfa said:
You may like this too?? :?: :?: :?:

http://www.youtube.com/watch?v=baaGOqIJaFM

Andrew Brown.
Sure do :cool:

This are mostly raw images ?
Hi EarthlingX, yes they are raw images. I have sorted them into some sort of order & made them available to SDC.
I know that about your post, very nice job, not to mention the trouble to put them on-line before official release, but was referring to images used in the video.

Here's a recently published very nice image of Janus :

saturn.jpl.nasa.gov : Blasted Janus
September 6, 2010 Full-Res: PIA12714



Saturn's moon Janus shows the scars of impacts in this Cassini spacecraft image of craters light and dark.

This view looks toward the Saturn-facing side of Janus (179 kilometers, or 111 miles across). North on Janus is up and rotated 10 degrees to the right.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 7, 2010. The view was acquired at a distance of approximately 75,000 kilometers (47,000 miles) from Janus and at a sun-Janus-spacecraft, or phase, angle of 39 degrees. Image scale is 448 meters (1,469 feet) per pixel.
 
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3488

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A sharpened crop enlargement of 179 KM wide Janus, as per EarthlingX's post above.


Tethys in front of Titan on: Saturday 17th October 2009. Sharpened enlargement by me.


Epimetheus, Janus, Prometheus & Atlas in front of Saturn's rings. Tuesday 27th July 2010.


Dione Saturday 4th September 2010 reorientated, north at top & enlarged sharpened by me. Dione appeared in front of the constellation of Crater the Cup during the approach.


Dione Saturday 4th September 2010 reorientated, north at top & enlarged sharpened by me. Graben are very evident here.


Dione north polar crescent. Saturday 4th September 2010 reorientated, north at top & enlarged sharpened by me. The Saturn lit nightside is clearly visible.


Andrew Brown.
 
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MeteorWayne

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Interesting rays from the crater at the 10 o'clock position in the first image.
 
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3488

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It is indeed Wayne.

Do you think it's ejecta or striations due to ice rubble sliding down inside to the floor?

Janus IIRC has a low density, only just above that of pure ice, so depsite it's reasonably large size, Janus will have a low surface gravity.

Andrew Brown.
 
K

kg

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Thanks Andrew Brown,
What an amazing mission, to see so many objects ["Epimetheus, Janus, Prometheus & Atlas in front of Saturn's rings"] within a single field of view!! A ring system, objects ranging in size from dust specks to small planets and plus of course Saturn itself, something new every week, every day even. To think you have to wait YEARS between targets on missions to the asteroid belt.

How is NASA handling all this data so that it remains useful into the future? I hope we don't need another project like (LOIRP) for Cassini 40 years from now!
Lunar Orbiter Image Recovery Project (LOIRP).
http://www.nasa.gov/topics/moonmars/features/LOIRP/
 
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3488

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kg":2wbu6hoh said:
Thanks Andrew Brown,
What an amazing mission, to see so many objects ["Epimetheus, Janus, Prometheus & Atlas in front of Saturn's rings"] within a single field of view!! A ring system, objects ranging in size from dust specks to small planets and plus of course Saturn itself, something new every week, every day even. To think you have to wait YEARS between targets on missions to the asteroid belt.

How is NASA handling all this data so that it remains useful into the future? I hope we don't need another project like (LOIRP) for Cassini 40 years from now!
Lunar Orbiter Image Recovery Project (LOIRP).
http://www.nasa.gov/topics/moonmars/features/LOIRP/
Hi kg,

With Cassini in orbit around Saturn, opportunities come up regularly. DAWN of course is ION propelled, hense the immensely long journey time to bodies that are not really that far away, but of course, the wait will be well worth while. Giant asteroid 4 Vesta next July. can't wait!!!!!!

Regarding LOIRP, much of that involves replaying original downloads through 21st Century equipment, thus at long last we can see exactly in full resolution & cleaned up what those five amazing preapollo orbiters actually returned. Much of it is from the Lunar Nearside is almost as good as being returned by LRO. :shock: It was a disgrace that some was lost, but fortunately has been found since. I understand that something similar had been done with the Viking Lander imagery (it was much better than originally shown as modern equipment can repoduce at higher resolution) as well as the Mariner 10 Mercury images.

I understand that the same will be done with the Voyager 2 Uranus system imagery. From Neptune encounter onwards it is unnecessary as technology had advanced enough to show returned material in full resolution.

Andrew Brown.
 
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3488

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More 1,123 KM wide Saturn moon Dione SPAM from me. I have reorientated them & contrast, sharpened enlarged a few. They are all clickable thumbnails.





Some closeups near & including Dione's North Pole.


Saturn lit night side of Dione. Sunlit terrain is on the extreme right.


Dione north polar crater with Saturn shine in the shadows.


Dione is a fascinating world.

Andrew Brown.
 
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3488

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Last spam from me for today (as the entire mambership of SDC rejoices) :D :D :D :mrgreen: :shock: .

Enlarged sharpend crops of 1,123 KM wide Dione by me from the Saturday 4th September 2010 pass.

Five global views below from a high northern latitude, complete with Saturn lit night side.











Crater approx 40 KM wide.


Crater on limb, image rotated 90 degrees counterclockwise, to make it look like a horizon..


Complex Heart Shaped Crater.


Grabens, extentional faulting. Dione here looks much like the Uranus moon Ariel.


Enough spam from me for one day perhaps :!: :!: :!: :!: :shock:
 
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3488

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LOL like the Monty Python SPAM song!!!!!!!!! Monty Python is my sort of humour!!! :lol: :lol: :lol: :lol:

Yes regarding craters.

Dione is composed of approx 46% rock (with a little iron), 54% ice & is the third densest of Saturn's moons after Titan & Enceladus with a mean density of 1.48 G/cm3.

Gravity data from Cassini suggests that Dione is diiferentiated to a very large extent, i.e a core, mantle & a crust. Core rocky, making up that 46% of the mass, ice mantle with a brittle ice crust.

I suspect those crater floors follow the profile of the harder crust under the looser ice / dust surface. Or impact melt fills the cavity & refreezes & would refreeze following the shape of Dione, as gravity will make that profile follow the 'level, as defined by the object's shape.

Think of Earth's oceans, they follow the curvature of the Earth. A bucket of water, a mug of coffee, etc. Their surfaces also follow the curvature of the Earth, only it is so small, we cannot see it do so, but it does!!!!!

Mind you, other bodies with large craters, i.e Mars, Ganymede, Callisto, Titan, Mercury, the Moon, etc, all show the same, i.e the crater floors follow the general shape of the body they're on, be it rocky like the Moon, Mercury or Mars, or icy / ice rich surfaces like Ganymede, Callisto, Titan, Dione, etc.

Andrew Brown.
 
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EarthlingX

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Thank you, very nice explanation :)

I had to run the spam song one more time, just in case :lol:
 
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EarthlingX

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saturn.jpl.nasa.gov : Biggest Saturnian Moons
September 20, 2010


Full-Res: PIA12724

darkly defined Rhea passes before the fuzzy orb of Titan in this Cassini view of Saturn's two largest moons.

Rhea is closer to the spacecraft in this view. See Ancient Plains of Rhea to learn more about Rhea. See Haze Layers on Titan to learn about Titan's atmosphere.

Lit terrain seen here is on the Saturn-facing sides of Rhea (1,528 kilometers, or 949 miles across) and Titan (5,150 kilometers, or 3,200 miles across).

The image was taken in visible blue light with the Cassini spacecraft narrow-angle camera on Nov. 19, 2009. The view was acquired at a distance of approximately 1.1 million kilometers (684,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 118 degrees. The view was acquired at a distance of approximately 2.3 million kilometers (1.4 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 118 degrees. Image scale is 7 kilometers (4 miles) per pixel on Rhea and 14 kilometers (9 miles) on Titan.
 
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EarthlingX

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http://www.europlanet-eu.org : Spring on Titan brings sunshine and patchy cloud

Left: T43 flyby of Titan - 12 May 2008 – VIMS images a large cloud that caps the north pole of Titan (yellowish tones).
Right: T63 flyby of Titan - 12 December 2009 – VIMS still observes a huge cloud system at 40°S (yellowish tones) and the north pole of Titan free of clouds, a few months after the equinox.
Credit: NASA/JPL/University of Arizona/University of Nantes/ University of Paris Diderot
Titan’s northern hemisphere is set for mainly fine spring weather, with polar skies clearing since the equinox in August last year. Cassini’s VIMS instrument has been monitoring clouds on Titan continuously since the spacecraft went into orbit around Saturn. Now, a team led by Sébastien Rodriguez (AIM laboratory - Université Paris Diderot) has used more than 2000 VIMS images to create the first long-term study of Titan’s weather that includes the equinox, using observational data. Dr Rodriguez will be presenting the results at the European Planetary Science Congress in Rome on Wednesday 22nd September.
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“Over the past six years, we’ve found that clouds appear clustered in three distinct latitude regions of Titan: large clouds at the north pole, patchy cloud at the south pole and a narrow belt around 40 degrees south. However, we are now seeing evidence of a seasonal circulation turnover on Titan – the clouds at the south pole completely disappeared just before the equinox and the clouds in the north are thinning out. This agrees with predictions from models and we are expecting to see cloud activity reverse from one hemisphere to another in the coming decade as southern winter approaches,” said Dr Rodriguez.
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Fractional cloud coverage in Titan’s atmosphere integrated between July 2004 and April 2010. Black areas are cloud free and yellow are fully covered.
Credit: NASA/JPL/University of Arizona/University of Nantes/ University of Paris Diderot
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3488

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Thanks EarthlingX,

Fascinating Titan update & supporting map too. What would be interesting is for NASA / JPL to produce cloud maps of Titan from every 'closish' pass to date & also from now on.

'New' Titan on Tuesday 21st September 2010 from Cassini.


Andrew Brown.
 
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orienteer

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Nice picture of Titan.

Why is the atmosphere not even from top to bottom (of the picture) I have two guesses. 1) refraction. The bottom is scattering more light and appears thicker. 2) temperature. the air on the bottom is being warmed by the sun more and therefore expands.
 
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3488

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orienteer":u0hdknj3 said:
Nice picture of Titan.

Why is the atmosphere not even from top to bottom (of the picture) I have two guesses. 1) refraction. The bottom is scattering more light and appears thicker. 2) temperature. the air on the bottom is being warmed by the sun more and therefore expands.
Hi orienteer,

First guess nearly correct. It was as you correctly said & also the sun was actually just behind the southern hemisphere, so more light was being refracted around that side.

Andrew Brown.
 
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EarthlingX

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saturn.jpl.nasa.gov : Scientist for a Day - 2010 Edition - Contest Overview
Cassini Scientist for a Day is an essay contest designed to give students a taste of life as a scientist. Students compare and research three possible targets that the Cassini spacecraft can image during a given time set aside for education. They are to choose the one observation they think will yield the best science results and explain their reasons in an essay.

The next edition of the contest is under way. Short videos in support of each observation are now available. The deadline for the contest is Oct. 27, 2010.

Students who participated in the last edition of Cassini Scientist for a Day asked scientists at NASA's Jet Propulsion Laboratory, Pasadena, Calif., questions about Saturn, its magnificent rings and the interesting moons in its orbit, including Titan and Tethys -- targets for the latest Fall 2009 edition of the essay contest.

Follow these links to review those targets:
Target 1: Saturn & Rings;
Target 2: Tethys & Rings and
Target 3: Titan .

The event has been recorded, and is available on Ustream.
Watch the Webcast (63 minutes)

Click on the image to download the flyer. (PDF, 120 KB)
 
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EarthlingX

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http://www.jpl.nasa.gov : New Views of Saturn's Aurora, Captured by Cassini
September 23, 2010


This false-color composite image, constructed from data obtained by NASA's Cassini spacecraft, shows the glow of auroras streaking out about 1,000 kilometers (600 miles) from the cloud tops of Saturn's south polar region. Image credit: NASA/JPL/University of Arizona/University of Leicester
Download wallpaper of this image



PASADENA, Calif. -- A new movie and images showing Saturn's shimmering aurora over a two-day period are helping scientists understand what drives some of the solar system's most impressive light shows.

The new, false-color images and video are available online at: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.

The movie and images are part of a new study that, for the first time, extracts auroral information from the entire catalogue of Saturn images taken by the visual and infrared mapping spectrometer instrument (VIMS) aboard NASA's Cassini spacecraft. These images and preliminary results are being presented by Tom Stallard, lead scientist on a joint VIMS and Cassini magnetometer collaboration, at the European Planetary Science Congress in Rome on Friday, Sept. 24.

In the movie, the aurora phenomenon clearly varies significantly over the course of a Saturnian day, which lasts around 10 hours 47 minutes. On the noon and midnight sides (left and right sides of the images, respectively), the aurora can be seen to brighten significantly for periods of several hours, suggesting the brightening is connected with the angle of the sun. Other features can be seen to rotate with the planet, reappearing at the same time and the same place on the second day, suggesting that these are directly controlled by the orientation of Saturn's magnetic field.

"Saturn's auroras are very complex and we are only just beginning to understand all the factors involved," Stallard said. "This study will provide a broader view of the wide variety of different auroral features that can be seen, and will allow us to better understand what controls these changes in appearance."
Auroras on Saturn occur in a process similar to Earth's northern and southern lights. Particles from the solar wind are channeled by Saturn's magnetic field toward the planet's poles, where they interact with electrically charged gas (plasma) in the upper atmosphere and emit light. At Saturn, however, auroral features can also be caused by electromagnetic waves generated when the planet's moons move through the plasma that fills Saturn's magnetosphere.
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Stallard and his colleagues have investigated about 1,000 images from the 7,000 that VIMS has taken to date of Saturn's auroral region.

The new, false-color images show Saturn's aurora glowing in green around the planet's south pole. The auroral information in the two images was extracted from VIMS data taken on May 24, 2007, and Nov. 1, 2008. The video covers about 20 Earth hours of VIMS observations, from Sept. 22 and 23, 2007.

"Detailed studies like this of Saturn's aurora help us understand how they are generated on Earth and the nature of the interactions between the magnetosphere and the uppermost regions of Saturn's atmosphere," said Linda Spilker, Cassini project scientist, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
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A quartet of false-color, composite images show the dance of Saturn's southern lights in data obtained by NASA's Cassini spacecraft. Image credit: NASA/JPL/University of Arizona/University of Leicester
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This movie, made from data obtained by NASA's Cassini spacecraft, shows Saturn's southern aurora shimmering over approximately 20 hours as the planet rotates. Image credit: NASA/JPL/University of Arizona/University of Leicester
Play video
 
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EarthlingX

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saturn.jpl.nasa.gov : Cassini Gazes at Veiled Titan
Jia-Rui Cook
Jet Propulsion Laboratory, Pasadena, Calif.

Sep. 23, 2010


Artist's view of the Titan Sept. 24 flyby.

NASA's Cassini spacecraft will swing high over Saturn's moon Titan on Friday, Sept. 24, taking a long, sustained look at the hazy moon. At closest approach, Cassini will fly within 8,175 kilometers (5,080 miles) above the hazy moon's surface. This flyby is the first in a series of high-altitude Titan flybys for Cassini over the next year and a half.

Cassini's composite infrared spectrometer instrument will be probing Titan's stratosphere to learn more about its vertical structure as the seasons change. Equinox, when the sun shone directly over the equator, occurred in August 2009, and the northern hemisphere is now in spring.

Another instrument, the visual and infrared mapping spectrometer, will be mapping an equatorial region known as Belet at a resolution of 5 kilometers (3 miles) per pixel. This mosaic will complement the mosaics that were obtained in earlier Titan flybys in January and April. This spectrometer will also look for clouds at northern mid-latitudes and near the poles.

Cassin's visible-light imaging cameras will also be taking images of Titan's trailing hemisphere, or the side that faces backward as Titan orbits around Saturn. If Titan cooperates and has a cloudy day, scientists plan to analyze the images for cloud patterns.

View T-72 Flyby Page

http://www.ciclops.org : Conjoined Moons


Looking like half of a figure eight, two of Saturn's moons appear conjoined in this Cassini image.

The moon Dione, at the top in the image, is actually closer to the spacecraft here. However, because of the similar albedo, or reflectivity, of the two moons and because of the location of a particularly large crater near the south polar region of Dione, the moon appears blended seamlessly with Rhea. The large, faint crater Evander is centered at about 57 degrees south latitude, 145 degrees west longitude and can also be seen in the Dione south polar map (see PIA12579).

Lit terrain seen here is on the anti-Saturn side of Dione (1123 kilometers, 698 miles across) and on the area between the anti-Saturn and leading hemisphere on Rhea (1528 kilometers, 949 miles across).

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 27, 2010. The view was acquired at a distance of approximately 1.1 million kilometers (688,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 78 degrees. The view was acquired at a distance of approximately 1.6 million kilometers (994,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 78 degrees. Image scale is 7 kilometers (4 miles) per pixel on Dione and 10 kilometers (6 miles) on Rhea.
..
Credit: NASA/JPL/Space Science Institute
Released: September 24, 2010 (PIA 12728)
Image Preparation: Daiana DiNino
Figure Caption: Thomas Roatsch, Joe Mason
 
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EarthlingX

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SDC : Cassini Spacecraft Zips Close By Saturn's Moon Titan
By SPACE.com Staff

posted: 25 September 2010
11:31 pm ET



A NASA spacecraft flew close by Saturn's largest moon, Titan, yesterday (Sept. 24) to take a close look at the moon's atmosphere and observe how its seasons change.

Cassini swung high over Titan, taking a long, sustained look at the hazy moon. At its closest approach — which occurred at 2:38 p.m. EDT (1838 GMT) — the spacecraft flew 5,080 miles (8,175 km) above Titan's surface.

This close look is the first in a new series of high-altitude Titan flybys Cassini will make over the next year and a half. The spacecraft has flown by Titan many times in the past as part of other science campaigns.
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EarthlingX

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saturn.jpl.nasa.gov : Hello, Saturn Summer Solstice: Cassini's New Chapter
Sep. 27, 2010


The Cassini spacecraft has been orbiting Saturn since June 30, 2004.

Turning a midsummer night's dream into reality, NASA's Cassini spacecraft begins its new mission extension -- the Cassini Solstice Mission -- today. The mission extension will take Cassini a few months past Saturn's northern summer solstice (or midsummer) through September 2017. It will enable scientists to study seasonal changes and other long-term weather changes on Saturn and its moons.

Cassini had arrived just after Saturn's northern winter solstice in 2004, and the extension continues a few months past the northern summer solstice in May 2017. A complete seasonal period on Saturn has never been studied at this level of detail.

Cassini has revealed a bounty of scientific discoveries since its launch in 1997, including previously unknown characteristics of the Earth-like world of Saturn's moon Titan, and the plume of water vapor and organic particles spewing from another moon, Enceladus.

The Cassini Solstice Mission will enable continued study of these intriguing worlds. It will also allow scientists to continue observations of Saturn's rings and the magnetic bubble around the planet, known as the magnetosphere. Near the end of the mission, the spacecraft will make repeated dives between Saturn and its rings to obtain in-depth knowledge of the gas giant. During these dives, the spacecraft will study the internal structure of Saturn, its magnetic fluctuations and ring mass.

Cassini entered orbit around Saturn in 2004. Mission managers had originally planned for a four-year tour of the Saturnian system. In 2008, Cassini received a mission extension through September 2010 to probe the planet and its moons through equinox, when the sun was directly over the equator. Equinox, which occurred in August 2009, marked the turn from southern fall to northern spring. The second mission extension, called the Cassini Solstice Mission, was announced earlier this year.

"After nearly seven years in transit and six years in Saturn orbit, this spacecraft still just hums along," said Bob Mitchell, Cassini program manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "With seven more years to go, the science should be just as exciting as what we've seen so far."
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EarthlingX

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www.universetoday.com : Simply Astonishing: Enceladus, the Jet-Powered Moon
Oct 1st 2010

by Nancy Atkinson


The plumes of Enceladus are highlighted in this Cassini image. Credit: NASA/JPL/Space Science Institute

What an astonishing view of Saturn‘s moon Enceladus, as seen by Cassini! At least four different plumes of water ice are spewing out from the south polar region, highlighted because of the black space behind the Moon. On Twitter, Carolyn Porco said that we see four jets because we’re looking down the four tiger stripe fractures crossing the south pole. “How lovely it is to know!” she added.

Cassini was about 617,000 kilometers (383,000 miles) away from Enceladus when it captured this image.

More info: Cassini website
 
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3488

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Titan on: Monday 27th September 2010. Largest clouds seen to date over the equator of the giant 5,150 KM wide moon of Saturn.

I have rotated the below image so north is top. The clouds are seen over the western limb.


Andrew Brown.
 
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