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The Official *Saturn* Exploration Thread


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The Official *Saturn* Exploration Thread
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curiousuburb
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2005-06-17, 12:23

Just when you thought you'd seen the wobbly F ring wake well... < or F wing if you're elmer fudd >

Pandora's Flocks


Quote:
June 17, 2005 Full-Res: PIA07523

The shepherd moon, Pandora, is seen here alongside the narrow F ring that it helps maintain. Pandora is 84 kilometers (52 miles) across.

Cassini obtained this view from about four degrees above the ringplane. Captured here are several faint, dusty ringlets in the vicinity of the F ring core. The ringlets do not appear to be perturbed to the degree seen in the core.

The appearance of Pandora here is exciting, as the moon's complete shape can be seen, thanks to reflected light from Saturn, which illuminates Pandora's dark side. The hint of a crater is visible on the dark side of the moon.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 4, 2005, at a distance of approximately 967,000 kilometers (601,000 miles) from Pandora and at a Sun-Pandora-spacecraft, or phase, angle of 117 degrees. The image scale is 6 kilometers (4 miles) per pixel.
Other releases of late include:
ring plane, F ring and volcano on Titan


Debating whether to start a Deep Impact thread...

Last edited by curiousuburb : 2005-06-17 at 12:26.
  quote
709
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2005-06-17, 12:53

Quote:
Originally Posted by curiousuburb
Debating whether to start a Deep Impact thread...
Do it! We're less than a month away...

Er, shit...almost 2 weeks away I should say...

Time flies.

Last edited by 709 : 2005-06-17 at 12:55.
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atomicbartbeans
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2005-06-17, 19:33

Am I the only one that thinks all these pictures look photoshopped?
  quote
BarracksSi
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2005-06-17, 23:13

Quote:
Originally Posted by atomicbartbeans
Am I the only one that thinks all these pictures look photoshopped?
I can understand where you're coming from, but these are still just digital images, and by the time we see them, they're compressed just like any other pic, too.

The fun thing about Photoshop is that any of us can make false color images of stuff like this. I can take that last pic, change it to RGB, and mess around with levels & curves to make ring features stand out even more. I wonder if it's at all like NASA has been doing for years.
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curiousuburb
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2005-06-18, 10:11

In general terms, PS is used to optimize and combine data in each colour channel... as to how...
while not specific to Cassini, we can look at the published info on Hubble...

Behind the Photos - http://hubblesite.org/sci.d.tech/behind_the_pictures/

Slate summarizes the process. - http://slate.msn.com/id/2120008/

PhotoShop Filters and Hubble - http://hubblesource.stsci.edu/servic...es/2005-02-10/
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curiousuburb
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2005-06-28, 20:36

Possible Lake on Titan (with animated clouds)


Quote:
NASA's Cassini Reveals Lake-like Feature on Titan
June 28, 2005
(Source: Jet Propulsion Laboratory)


This view of Titan's south polar region reveals an intriguing dark feature that may be the site of a past or present lake of liquid hydrocarbons.
+ See Time-Lapse Movie
Scientists are fascinated by a dark, lake-like feature recently observed on Saturn's moon Titan. NASA's Cassini spacecraft captured a series of images showing a marking, darker than anything else around it. It is remarkably lake-like, with smooth, shore-like boundaries unlike any seen previously on Titan.

"I'd say this is definitely the best candidate we've seen so far for a liquid hydrocarbon lake on Titan," said Dr. Alfred McEwen, Cassini imaging team member and a professor at the University of Arizona, Tucson. The suspected lake area measures 234 kilometers long by 73 kilometers wide (145 miles by 45 miles), about the size of Lake Ontario, on the U.S. Canadian border.

"This feature is unique in our exploration of Titan so far," said Dr. Elizabeth Turtle, Cassini imaging team associate at the University of Arizona. "Its perimeter is intriguingly reminiscent of the shorelines of lakes on Earth that are smoothed by water erosion and deposition."

The feature lies in Titan's cloudiest region, which is presumably the most likely site of recent methane rainfall. This, coupled with the shore-like smoothness of the feature's perimeter makes it hard for scientists to resist speculation about what might be filling the lake, if it indeed is one.

"It's possible that some of the storms in this region are strong enough to make methane rain that reaches the surface," said Cassini imaging team member Dr. Tony DelGenio of NASA's Goddard Institute for Space Studies in New York.

"Given Titan's cold temperatures, it could take a long time for any liquid methane collecting on the surface to evaporate. So it might not be surprising for a methane-filled lake to persist for a long time," DelGenio added. Despite earlier predictions, no definitive evidence for open bodies of liquid has been found on Titan. Cassini has not yet been in a favorable position for using its cameras to check for glints from possible surface liquids in the south polar region.

"Eventually, as the seasons change over a few years, the convective clouds may migrate northward to lower latitudes," said DelGenio, "If so, it will be interesting to see whether the Cassini cameras record changes in the appearance of the surface as well."

"An alternate explanation is that this feature was once a lake, but has since dried up, leaving behind dark deposits," Turtle said. Yet another possibility is that the lake is simply a broad depression filled by dark, solid hydrocarbons falling from the atmosphere onto Titan's surface. In this case, the smooth outline might be the result of a process unrelated to rainfall, such as a sinkhole or a volcanic caldera.

"It reminds me of the lava lakes seen on Jupiter's moon, Io," Dr. Torrence Johnson, an imaging team member at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"It is already clear that whatever this lake-like feature turns out to be, it is only one of many puzzles that Titan will throw at us as we continue our reconnaissance of the surface over the next few years," said Dr. Carolyn Porco, imaging team leader at the Space Science Institute in Boulder, Colo.

Thirty-nine more Titan flybys are planned for Cassini's prime mission. In future flybys the science teams will search for opportunities to observe the lake feature again and to look for mirror-like reflections from smooth surfaces elsewhere on Titan. Such reflections would strongly support the presence of liquids.
for more info, or the alternate cloud caption, click here

Last edited by curiousuburb : 2005-06-28 at 23:00.
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Kickaha
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2005-07-02, 00:33

Not only do the rings have an O2 atmosphere of sorts, but Saturn is rotating slower than when Voyager and Pioneer went by? <jon_stewart>whaaaaaaaaaaa?</jon_stewart>

http://news.bbc.co.uk/2/hi/science/nature/4640641.stm

Two words: Fun. Key.

(Yes, easiest explanation is that the sensor data somehow differs between then and now, or the interpretation methodology.)
  quote
curiousuburb
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2005-07-02, 02:05

Quote:
Originally Posted by Kickaha
Not only do the rings have an O2 atmosphere of sorts, but Saturn is rotating slower than when Voyager and Pioneer went by? <jon_stewart>whaaaaaaaaaaa?</jon_stewart>

http://news.bbc.co.uk/2/hi/science/nature/4640641.stm

Two words: Fun. Key.

(Yes, easiest explanation is that the sensor data somehow differs between then and now, or the interpretation methodology.)
So the rings have an oxygen atmosphere and an energy source... I see a new sci-fi ecosystem set for novelization or hollywood.

You read it here first. Kickaha and I (on behalf of AN) claim royalties.
  quote
curiousuburb
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2005-07-06, 11:50

And for a non-Cassini perspective for a change, Space.com offers Saturn in Visible and X-Ray


Quote:
Sparkling Saturn

Saturn's rings light up with bright blue highlights, in this blend of both visual and X-ray observations.

Astronomers believe that fluorescence caused when solar X-rays smack into the oxygen molecules locked with in Saturn’s icy ring water.

As seen in this image, most of the X-rays among Saturn’s rings come from the B ring, the bright white, inner ring in the optical image of the planet.

There is some evidence for a concentration of X-rays on the morning side (left side, also called the East ansa) of the rings, possibly because X-rays are associated with optical features called spokes that are largely confined to the dense B ring and most often seen on the morning side.

Spokes are due to transient clouds of fine ice-dust particles that are lifted off the ring surface. It has been suggested that the spokes are triggered by meteoroid impacts, which are more likely in the midnight to early morning hours because during that period the relative speed of the rings through a cloud of meteoroids would be greater.

The higher X-ray brightness on the morning side of the rings could be due to the additional solar fluorescence from the transient ice clouds that produce the spokes. This explanation may also account for other Chandra observations of Saturn, which show that the X-ray brightness of the rings varies significantly from one week to the next.

Credit: X-ray: NASA/MSFC/CXC/A.Bhardwaj et al.; Optical: NASA/ESA/STScI/AURA
They have previously reported on puzzling results from science in these bands and compared Chandra and HST


Quote:
Chandra's image of Saturn held some surprises for the observers. First, Saturn's 90 megawatts of X-radiation is concentrated near the equator. This is different from a similar gaseous giant planet, Jupiter, where the most intense X-rays are associated with the strong magnetic field near its poles.
Credit: X-ray: NASA/U. Hamburg/J.Ness et al; Optical: NASA/STScI

Last edited by curiousuburb : 2005-07-06 at 11:53.
  quote
curiousuburb
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2005-07-26, 04:10

Hot on the heels of the recent Top 10 Cassini Science Highlights,

check out the latest spooky Sounds of Saturn

click for 127kb WAV file
Quote:
Saturn's radio emissions could be mistaken for a Halloween sound track. That's how two researchers describe their recent findings, published in the July 23 issue of the Geophysical Research Letters. Their paper is based on data from the Cassini spacecraft radio and plasma wave science instrument. The study investigates sounds that are not just eerie, but also descriptive of a phenomenon similar to Earth's northern lights.

"All of the structures we observe in Saturn's radio spectrum are giving us clues about what might be going on in the source of the radio emissions above Saturn's auroras," said Dr. Bill Kurth, deputy principal investigator for the instrument. He is with the University of Iowa, Iowa City. Kurth made the discovery along with Principal Investigator Don Gurnett, a professor at the University. "We believe that the changing frequencies are related to tiny radio sources moving up and down along Saturn's magnetic field lines."

Samples of the resulting sounds can be heard at www.nasa.gov/cassini , http://saturn.jpl.nasa.gov and http://www-pw.physics.uiowa.edu/cassini/ .

The radio emissions, called Saturn kilometric radiation, are generated along with Saturn's auroras, or northern and southern lights. Because the Cassini instrument has higher resolution compared to a similar instrument on NASA's Voyager spacecraft, it has provided more detailed information on the spectrum and the variability of radio emissions. The high-resolution measurements allow scientists to convert the radio waves into audio recordings by shifting the frequencies down into the audio frequency range.

The terrestrial cousins of Saturn's radio emissions were first reported in 1979 by Gurnett, who used an instrument on the International Sun-Earth Explorer spacecraft in Earth orbit. Kurth said that despite their best efforts, scientists still haven't agreed on a theory to fully explain the phenomenon. They will get another chance to solve the radio emission puzzle beginning in mid-2008 when Cassini will fly close to, or possibly even through, the source region at Saturn. Gurnett said, "It is amazing that the radio emissions from Earth and Saturn sound so similar." Other contributors to the paper include University of Iowa scientists George Hospodarsky and Baptiste Cecconi; Mike Kaiser (currently at Goddard Space Flight Center, Greenbelt, Md.); French scientists Philippe Louarn, Philippe Zarka and Alain Lecacheux; and Austrian scientists Helmut Rucker and Mohammed Boudjada. Cassini, carrying 12 scientific instruments, on June 30, 2004, became the first spacecraft to orbit Saturn. It is conducting a four-year study of the planet, its rings and many moons. The spacecraft carried the Huygens probe, a six-instrument European Space Agency probe that landed on Titan, Saturn's largest moon, in January 2005.
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curiousuburb
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2005-09-30, 05:47

Spongy and Lavalike moons and more

Hyperion

Click pic above for links to QT movie of Hyperion flyby.

Quote:
Cassini performed back-to-back flybys of Saturn moons Tethys and Hyperion last weekend, coming closer than ever before to each of them. Tethys has a scarred, ancient surface, while Hyperion is a strange, spongy-looking body with dark-floored craters that speckle its surface.
Click for news of 'doubleheader' flyby.


False colour close-up of Tethys. Click for details.

Quote:
This view is among the closest Cassini images of Tethys' icy surface taken during the Sept. 24, 2005 flyby.
This false-color image, created with infrared, green and ultraviolet frames, reveals a wide variety of surface colors across this terrain. The presence of this variety at such small scales may indicate a mixture of different surface materials. Tethys was previously known to have color differences on its surface, especially on its trailing side, but this kind of color diversity is new to imaging scientists. For a clear-filter view of this terrain, see PIA07736.
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Brad
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2005-10-01, 20:46

Keep up the posts, 'burb! While it may not be generating a lot of discussion here, I find the information from these links fascinating and am glad you're posting them.

The quality of this board depends on the quality of the posts. The only way to guarantee thoughtful, informative discussion is to write thoughtful, informative posts. AppleNova is not a real-time chat forum. You have time to compose messages and edit them before and after posting.
  quote
Moogs
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2005-10-01, 21:13

Wow...

...Hyperion is really strange looking. Almost expect a place like that to have little demonic aliens lying in wait.
  quote
curiousuburb
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2005-10-06, 06:07

F ring detail (and damage)...



Quote:
Drawing the Drapes
October 5, 2005 Full-Res: PIA07601

Prometheus poses here with its latest creation: a dark, diagonal gore in the tenuous material interior to Saturn's F ring. The shepherd moon creates a new gore each time it comes closest to the F ring in its orbit of Saturn, and the memory of previous passes is preserved in the rings's structure for some time afterward. Prometheus is 102 kilometers (63 miles) across.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 20, 2005, at a distance of approximately 499,000 kilometers (310,000 miles) from Saturn and at a high Sun-Saturn-spacecraft, or phase, angle of 144 degrees. Resolution in the original image was 3 kilometers (2 miles) per pixel.
  quote
curiousuburb
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2005-10-18, 16:57

Cassini's latest stunning pic...

Ringside with Dione



October 17, 2005 Full-Res: PIA07744

Quote:
Speeding toward pale, icy Dione, Cassini's view is enriched by the tranquil gold and blue hues of Saturn in the distance. The horizontal stripes near the bottom of the image are Saturn's rings. The spacecraft was nearly in the plane of the rings when the images were taken, thinning them by perspective and masking their awesome scale. The thin, curving shadows of the C ring and part of the B ring adorn the northern latitudes visible here, a reminder of the rings' grandeur.
It is notable that Dione, like most of the other icy Saturnian satellites, looks no different in natural color than in monochrome images.

Images taken on Oct. 11, 2005, with blue, green and infrared (centered at 752 nanometers) spectral filters were used to create this color view, which approximates the scene as it would appear to the human eye. The images were obtained with the Cassini spacecraft wide-angle camera at a distance of approximately 39,000 kilometers (24,200 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 22 degrees. The image scale is about 2 kilometers (1 mile) per pixel.
and Flicks

Quote:
QuickTime (sm, no audio) (3.5 MB) QuickTime (lg, no audio) (9.9 MB)

Ice Moon Rendezvous Full-Res: PIA07749

Zooming in closer and closer, this movie chronicles Cassini's targeted flyby of Dione, with Saturn and its lovely rings forming a dramatic backdrop.
The movie begins with Cassini during its approach about 107,000 kilometers (66,000 miles) from the icy moon. Few surface details are discernable from this distance, but the view quickly improves. The movie jumps to a point 39,000 kilometers (24,000 miles) from Dione, with Saturn's atmosphere now in the background and draped by threadlike ring shadows.

As the spacecraft gets still closer, the camera focuses on bright fractures in the west. It becomes apparent that these braided canyons slice through older craters. At the closest point in this approach sequence, Cassini is about 4,000 kilometers (2,500 miles) above Dione's surface and the image scale is 234 meters (768 feet) per pixel. For a narrow-angle camera image taken at almost the same instant see PIA07748.

A dramatic shift in perspective follows, with Cassini moving past the point of closest approach and staring at a large crater on Dione's receding limb. Steep cliffs gleam in the sunlight as the intrepid craft pulls away. About three and a half hours have elapsed since the first image in the movie was taken.

This movie was created from clear-filter images taken during the Oct. 11, 2005, flyby of Dione. All images except the departing view were obtained with the Cassini spacecraft wide-angle camera.
You can clearly see the central peak in the receding crater in the final shots of the movie, and in both the main image and both movies you really get a sense of just how thin the rings are. The ring shadow on Saturn is a nice touch, too.

Brilliant stuff.

Last edited by curiousuburb : 2005-10-18 at 17:18.
  quote
julesstoop
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2005-10-18, 17:10

From the same release, check the extremely hi-rez (7600*2000 pix.) image of Dione's crescent Cassini took when looking back:

http://ciclops.org/view.php?id=1584
  quote
curiousuburb
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2005-10-18, 17:19

Quote:
Originally Posted by julesstoop
From the same release, check the extremely hi-rez (7600*2000 pix.) image of Dione's crescent Cassini took when looking back:

http://ciclops.org/view.php?id=1584
Damn, that looks cold...
  quote
curiousuburb
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2005-10-31, 05:25

For a switch of senses as a seasonal trick/treat, click the link for

  quote
oldmacfan
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2005-10-31, 10:10

Stunning pics
  quote
curiousuburb
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2005-12-07, 08:31

And you think it's cold where you are...



Quote:
Season of Moons
December 6, 2005 Full-Res: PIA07767

This montage shows four major icy moons of Saturn that the Cassini spacecraft visited while surveying the Saturnian system during 2005. Even though all of these bodies are made largely of ice, they exhibit remarkably different geological histories and varied surface features.
Craters from meteorite impacts are common features on all of these moons. But since the major moons of Saturn are thought to have all formed at approximately the same time, the different distribution of sizes, shapes and numbers of craters on each of their surfaces tell scientists a great deal about the differences in their geologic histories.

Rhea and Iapetus are thoroughly peppered by impacts, suggesting their surfaces have been exposed to the shooting gallery of space for eons. Dione appears to have regions of terrain that are smoother, with fewer craters, suggesting a slightly younger surface. Dione also has a large system of bright, braided fractures that suggest tectonic activity took place there some time after the moon first formed.

Enceladus, however, possesses a region of terrain near its south pole (shown here), that is so dramatically devoid of impact sites that scientists suspected it was geologically active in the recent past, and perhaps even today. The discovery this year of material jetting from the pole and creating a great plume of icy particles confirmed these suspicions. See Fountains of Enceladus for images of the Enceladus plume.

More on the Enceladus Plume
Click for links to QT Movie


The processes that power the activity on Enceladus remain elusive, as do those that produced the pronounced equatorial bulge on Iapetus. This feature was imaged for the first time by Cassini during a flyby of Iapetus that began New Year's Day. The bulge on Iapetus reaches 20 kilometers (12 miles) above the surrounding terrain in places, making it one of the tallest features in the solar system.

Like many scientific journeys, Cassini's historic survey of Saturn's moons has raised more questions. For example, why small Enceladus (505 kilometers, or 314 miles across) is presently geologically active while much larger Rhea (1,528 kilometers, or 949 miles across) is not. Fortunately, such puzzles are the most exciting sort for scientists interested in uncovering the secrets of Saturn's realm.
Also of note recently have been more releases on Titan, including movies of the descent and landing site calculated from the last imaging flyby (some with radar).
Descent Imager Landing site movie Descent movie

The Nov 30th ESA Press conference on Mars Express and Huygens results is now online
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curiousuburb
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2005-12-15, 10:15

Ring Shepherds and Deformation Trails.

In honour of the Forum update and it's scrollable individual posts, I'm including a slightly crisper image here than the usual clickable size, mostly to showcase the trailing ice particles from the F ring which are following Prometheus (at left) out of the ring plane (although apparently following behind Pandora on the right).



Quote:
Close to the Shepherd Moons
December 15, 2005 Full-Res: PIA07653

This spectacular image shows Prometheus (at left) and Pandora (at right), with their flock of icy ring particles (the F ring) between them. Pandora is exterior to the ring, and closer to the spacecraft here. Each of the shepherd satellites has an unusual shape, with a few craters clearly visible.
The effect of Prometheus (102 kilometers, or 63 miles across) on the F ring is visible as it pulls material out of the ring when it is farthest from Saturn in its orbit. Pandora is 84 kilometers (52 miles) across.

The image was taken in polarized green light with the Cassini spacecraft narrow-angle camera on Oct. 29, 2005, at a distance of approximately 459,000 kilometers (285,000 miles) from Pandora and 483,500 kilometers (300,500 miles) from Prometheus. The image scale is 3 kilometers (2 miles) per pixel on Pandora and 3 kilometers (2 miles) per pixel on Prometheus. The view was acquired from about a third of a degree below the ringplane.
The image from a few days ago showed further deformation in the edge of the F ring when viewed edge on.



Quote:
On the Edge
December 13, 2005 Full-Res: PIA07651

Viewing Saturn's rings very close to edge-on produces some puzzling effects, as these two images of the F ring demonstrate.
The upper image was acquired from less than a tenth of a degree beneath the ringplane and shows a mysterious bulge. Such a feature has not been seen previously by the Cassini spacecraft from this angle. It is possible that, because of the very shallow viewing angle, the Cassini spacecraft's view takes a long path through the ring, making very faint material visible. It also may be that an embedded object of a kilometer or so in size stirs up the neighboring ring particles to create a bulge. Alternatively, an impact into an embedded moonlet that was covered with debris could produce a cloud like this.

Images taken by the Voyager spacecrafts showed clumps that might have been produced in these ways. Cassini's investigations will help to determine the vertical extent of such clumps and understand their origins.

The lower image was obtained from less than a hundredth of a degree beneath the ringplane. Across the center of the rings is a dark lane, giving them an appearance not unlike that of a spiral galaxy, seen edge-on.

Both images were taken using the clear spectral filters (predominantly visible light) on the Cassini spacecraft narrow-angle camera. The images have been magnified by a factor of two.

The top image was obtained at a distance of 3.6 million kilometers (2.2 million miles) from Saturn on Nov. 11, 2005 and shows wispy fractures on Dione's trailing hemisphere. The image scale is 22 kilometers (14 miles) per pixel. The bottom image was acquired at a distance of 2.5 million kilometers (1.6 million miles) from Saturn on Nov. 5, 2005. The image scale is 15 kilometers (9 miles) per pixel.
Keeners might also be interested in some new false colour images of Dionne and Rhea and Hyperion , as well as new images of clouds in the upper atmosphere, which the NASA/ESA folks are describing as "cirrus-like"

Last edited by curiousuburb : 2005-12-15 at 10:20.
  quote
curiousuburb
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2006-03-03, 07:34

Updates:

Relief on Iapetus, the two-faced Moon



Quote:
To the Relief of Iapetus
March 2, 2006 Full-Res: PIA08125

Sunlight strikes the terminator (the boundary between day and night) region on Saturn's moon Iapetus at nearly horizontal angles, making visible the vertical relief of many features.
This view is centered on terrain in the southern hemisphere of Iapetus (1,468 kilometers, or 912 miles across). Lit terrain visible here is on the moon's leading hemisphere. In this image, a large, central-peaked crater is notable at the boundary between the dark material in Cassini Regio and the brighter material on the trailing hemisphere.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 22, 2006, at a distance of approximately 1.3 million kilometers (800,000 miles) from Iapetus and at a Sun-Iapetus-spacecraft, or phase, angle of 67 degrees. Resolution in the original image was 8 kilometers (5 miles) per pixel. The image has been magnified by a factor of two and contrast-enhanced to aid visibility.
Titan's Hood through the Haze (with Tethys on the left)



Quote:
Saturnian Specters
March 1, 2006 Full-Res: PIA08124

Ghostly details make this dark scene more than just a beautiful grouping of two Saturn moons, with Tethys on the left and Titan on the right. In Titan's thick and inflated atmosphere, the detached high haze layer can be seen, as well as the complex northern polar hood (at the top). Images like this one can help scientists make definitive estimates of the altitudes to which the high haze extends.
The faint vertical banded pattern is a type of noise that usually is removed during image processing. Because this image was processed to enhance the visibility of details in Titan's atmosphere and the faint G ring, the vertical noise was also enhanced.

Titan is Saturn's largest moon, at 5,150 kilometers (3,200 miles) across. Tethys is 1,071 kilometers (665 miles) across.

This view was obtained in visible light with the Cassini spacecraft narrow-angle camera on Jan. 19, 2006, at a distance of approximately 2.4 million kilometers (1.5 million miles) from Titan and 1 million kilometers (600,000 miles) from Tethys. The image scale is 14 kilometers (9 miles) per pixel on Titan and 6 kilometers (4 miles) per pixel on Tethys.
And the latest shot of the edge of the F Ring seems to show a spiral pattern...



Quote:
F Ring Edge
February 28, 2006 Full-Res: PIA08123

Structure in Saturn's narrow and complex F ring is seen here, including one of the faint strands (at the left) that Cassini has shown to curl around the planet in a tight, rotating spiral. Scientists think the spiral structure might be due to disturbance of micron-sized F-ring particles by a tiny moon (or moons).
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 19, 2006, at a distance of approximately 1.2 million kilometers (700,000 miles) from Saturn and from just above the ringplane. The image scale is 7 kilometers (4 miles) per pixel.

Last edited by curiousuburb : 2006-03-03 at 07:40.
  quote
Moogs
Hates the Infotainment
 
Join Date: May 2004
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2006-03-09, 20:18

Interesting find today!

Quote:
The orbiting Cassini spacecraft has spotted what appear to be water geysers on one of Saturn's icy moons, raising the tantalizing possibility that the celestial object harbors life.

The surprising images from the moon Enceladus represent some of the most dramatic evidence yet that water in liquid form may be present beyond the Earth.

Excited by the discovery, some scientists said Enceladus should be added to the short list of places within the solar system most likely to have extraterrestrial life.
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curiousuburb
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2006-03-09, 20:47

Quote:
Originally Posted by Moogs
Interesting find today!
Dude, I was just going to update this thread with the CNN story...



Here's the full version:

Quote:


Full text of teh CNN article.

The Cassini spacecraft has found evidence of liquid water spewing from geysers on one of Saturn's icy moons,[/b] raising the tantalizing possibility that the celestial object harbors life.

The surprising discovery excited some scientists, who say the Saturn moon, Enceladus, should be added to the short list of places within the solar system most likely to have extraterrestrial life.

Recent high-resolution images snapped by the orbiting Cassini confirmed the eruption of icy jets and giant water vapor plumes from geysers resembling frozen Old Faithfuls at Enceladus' south pole. (Watch NASA's Dr. Torrence Johnson talk about the importance of finding liquid water on Enceladus -- 1:22)

"We have the smoking gun" that proves the existence of water, said Carolyn Porco, a Cassini imaging scientist from the Space Science Institute in Boulder, Colorado.

If Enceladus does harbor life, it probably consists of microbes or other primitive organisms capable of living in extreme conditions, scientists say.

The findings were published in Friday's issue of the journal Science.

David Morrison, a senior scientist at NASA's Astrobiology Institute, cautioned against rushing to judgment about whether the tiny moon could support life. Scientists generally agree habitats need several ingredients for life to emerge, including water, a stable heat source and the right chemical recipe.

"It's certainly interesting, but I don't see how much more you can say beyond that," Morrison said.

Scientists believe Mars and Jupiter's icy moons might have -- or once had -- conditions hospitable to life.

Saturn is around 800 million miles from Earth. Enceladus measures 314 miles (505 kilometers) across and is the shiniest object in the solar system.

It was long thought to be cold and still. But scientists now believe it is a geologically active moon that possesses an unusually warm south pole.

The water is believed to vent from fissures in the south pole. Porco said the venting has probably been going on for at least several thousand years, potentially providing a lasting heat source.

The Cassini-Huygens mission is a joint NASA-European Space Agency project. The spacecraft was launched in 1997 and went into orbit around Saturn in 2004, exploring its spectacular rings and many moons.

Cassini made three flybys of Enceladus last year and is expected to fly within 220 miles (354 kilometers) of the moon again in 2008.
NASA version






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Last edited by curiousuburb : 2006-03-10 at 07:25.
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Moogs
Hates the Infotainment
 
Join Date: May 2004
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2006-03-09, 20:54

Niiiice.
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curiousuburb
Antimatter Man
 
Join Date: May 2004
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2006-03-30, 09:22

Crank up the Katie Melua and get another rewrite for her bicycle tune...

Cassini Team adds to the Saturnian Moon count...

+10 Million Moonlets (propellers)



Quote:
Cassini Finds 'Missing Link' Moonlet Evidence in Saturn's Rings
March 29, 2006

Scientists with NASA's Cassini mission have found evidence that a new class of small moonlets resides within Saturn's rings. There may be as many as 10 million of these objects within one of Saturn's rings alone. The propeller moonlets represent a hitherto unseen size-class of particles orbiting within the rings.

The moonlets' existence could help answer the question of whether Saturn's rings were formed through the break-up of a larger body or are the remnants of the disk of material from which Saturn and its moons formed.

"These moonlets are likely to be chunks of the ancient body whose break-up produced Saturn's glorious rings," said Joseph Burns of Cornell University, Ithaca, N.Y., a co-author of the report.

Careful analysis of high-resolution images taken by Cassini's cameras revealed four faint, propeller-shaped double streaks. These features were found in an otherwise bland part of the mid-A Ring, a bright section in Saturn's main rings. Cassini imaging scientists reporting in this week's edition of the journal Nature believe the "propellers" provide the first direct observation of how moonlets of this size affect nearby particles. Cassini took the images as it slipped into Saturn orbit on July 1, 2004.

Previous measurements, including those made by NASA's Voyager spacecraft in the early 1980s, have shown that Saturn's rings contain mostly small water-ice particles ranging from less than 1 centimeter (one-half inch) across to the size of a small house. Scientists knew about two larger embedded ring moons such as 30-kilometer-wide (19-mile) Pan and 7-kilometer-wide (4-mile) Daphnis. The latest findings mark the first evidence of objects of about 100 meters (300 feet) in diameter. From the number of moonlets spotted in the very small fraction of the A ring seen in the images, scientists estimated the total number of moonlets to be about 10 million.

"The discovery of these intermediate-sized bodies tells us that Pan and Daphnis are probably just the largest members of the ring population, rather than interlopers from somewhere else," said Matthew Tiscareno, an imaging team research associate at Cornell and lead author on the Nature paper.

Moons as large as Pan and Daphnis clear large gaps in the ring particles as they orbit Saturn. In contrast, smaller moonlets are not strong enough to clear out the ring, resulting in a partial gap centered on the moonlet and shaped like an airplane propeller. Such features created by moonlets were predicted by computer models, which give scientists confidence in their latest findings.

"We acquired this spectacular, one-of-a-kind set of images immediately after getting into orbit for the express purpose of seeing fine details in the rings that we had not seen previously," said Carolyn Porco, Cassini imaging team leader and co-author. "This will open up a new dimension in our exploration of Saturn's rings and moons, their origin and evolution."

The detection of moonlets embedded in a ring of smaller particles may provide an opportunity to observe the processes by which planets form in disks of material around young stars, including our own early solar system. "The structures we observe with Cassini are strikingly similar to those seen in many numerical models of the early stages of planetary formation, even though the scales are dramatically different," said co-author Carl Murray, an imaging team member at Queen Mary, University of London. "Cassini is giving us a unique insight into the origin of planets."
Quote:
Locating the Propellers
March 29, 2006 Full-Res: PIA07792

This collection of Cassini images provides context for understanding the location and scale of propeller-shaped features observed within Saturn's A ring.
Careful analysis of the highest resolution images taken by Cassini's cameras as the spacecraft slipped into Saturn orbit revealed the four faint, propeller-shaped double-streaks in an otherwise bland part of the mid-A ring. Imaging scientists believe the "propellers" provide the first direct observation of the dynamical effects of moonlets approximately 100 meters (300 feet) in diameter. The propeller moonlets represent a hitherto unseen size-class of particles orbiting within the rings.

The left-hand panel provides broad context within the rings, and shows the B ring, Cassini Division, A ring and F ring. Image scale in the radial, or outward from Saturn, direction is about 45 kilometers (28 miles) per pixel; because the rings are viewed at an angle, the image scale in the longitudinal, or circumferential, direction is several times greater.

The center image is a closer view of the A ring, showing the radial locations where propeller features were spotted. The view is approximately 1,800 kilometers (1,100 miles) across from top to bottom and includes a large density wave at bottom (caused by the moons Janus and Epimetheus), as well as two smaller density waves. The footprints of the propeller discovery images are between density waves, in bland, quiescent regions of the ring.

The propellers appear as double dashes in the two close-up discovery images at the right and are circled. The unseen moonlets, each roughly the size of a football field, lie in the center of each structure. These two images were taken during Saturn orbit insertion on July 1, 2004, and are presented here at one-half scale. Resolution in the original images was 52 meters (171 feet) per pixel. The horizontal lines in the image represent electronic noise and do not correspond to ring features.

The propellers are about 5 kilometers (3 miles) long from tip to tip, and the radial offset (the "leading" dash is slightly closer to Saturn) is about 300 meters (1,000 feet).

The propeller structures are unchanged as they orbit the planet. In that way, they are much like the wave pattern that trails after a speedboat as it skims across a smooth lake. Such a pattern is hard to discern in a choppy sea. In much the same way, scientists think other effects may be preventing Cassini from seeing the propellers except in very bland parts of the rings.

See Four Propellers and Propeller Motion for additional images showing these features.
That's an awful lot of new names to come up with...
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drewprops
Space Pirate
 
Join Date: May 2004
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2006-04-05, 23:06

The NOVA show on Saturn is running right now, which coincides with my current reading material, Ben Bova's Saturn. Fun!
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curiousuburb
Antimatter Man
 
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2006-04-19, 06:15

Lovely new image as an update...

Combinations of cloud patterns, ring shadow detail, thin ring plane, and moons...



Quote:
A Complex Crescent
April 18, 2006 Full-Res: PIA08159

The tilted crescent of Saturn displays lacy cloud bands here along with a bright equatorial region and threadlike ring shadows on the northern hemisphere.
Three moons are visible here. Mimas (397 kilometers, or 247 miles across) at left and faint, is aligned with the ringplane. At right are Rhea (1,528 kilometers, or 949 miles across, at top) and Tethys (1,071 kilometers, or 665 miles across, below Rhea).

The image was taken in polarized infrared light with the Cassini spacecraft wide-angle camera on March 11, 2006, at a distance of approximately 2.8 million kilometers (1.8 million miles) from Saturn. The image scale is 166 kilometers (103 miles) per pixel.

All those who believe in telekinesis, raise my hand.
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curiousuburb
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2006-05-06, 07:45

New Videos of Titan landing

Quote:
New views of the most distant touchdown ever made by a spacecraft are being released today by NASA, the European Space Agency and the University of Arizona. The movies show the dramatic descent of the Huygens probe to the surface of Saturn's moon Titan on Jan. 14, 2005.

The movies were put together with data collected by the Descent Imager/Spectral Radiometer instrument during the probe's 147-minute plunge through Titan's thick orange-brown atmosphere to a soft sandy riverbed. The Descent Imager/Spectral Radiometer was funded by NASA.

The data were analyzed for months after the landing and represent the best visual product obtained from the Huygens mission. It is the most realistic way yet to experience the Huygens probe landing. The movie "View from Huygens on Jan. 14, 2005," provides in 4 minutes and 40 seconds of what the probe actually "saw" during the 2.5 hours of the descent and touchdown.

"At first, the Huygens camera just saw fog over the distant surface," said Erich Karkoschka, team member at the University of Arizona, Tucson, and creator of the movies. "The fog started to clear only at about 60 kilometers [37 miles] altitude, making it possible to resolve surface features as large as 100 meters [328 feet]," he said. "But only after landing could the probe's camera resolve little grains of sand millions and millions of times smaller than Titan. A movie is a perfect medium to show such a huge change of scale."

For the second movie, scientists used artistic license and added sound to represent the different data sets collected. They re-created a scientifically accurate representation of the mission life in less than five minutes.

"These movies really demonstrate that the Huygens camera was very well designed for the job," said Jean-Pierre Lebreton, Huygens project scientist and mission manager at the European Space Agency. "They show so many different details of a landscape that covers only a tiny fraction -- one-thousandth -- of Titan's surface. This makes me dream of what a possible future mission to Titan may return of this wonderful and fascinating Earth-like world," he said.
New Titan Descent Movie (Now with Bells and Whistles)



10MB QT Animation

Quote:
This movie, built with data collected during the European Space Agency's Huygens probe on Jan. 14, 2005, shows the operation of the Descent Imager/Spectral Radiometer camera during its descent and after touchdown. The camera was funded by NASA.
The almost four-hour-long operation of the camera is shown in less than five minutes. That's 40 times the actual speed up to landing and 100 times the actual speed thereafter.

The first part of the movie shows how Titan looked to the camera as it acquired more and more images during the probe's descent. Each image has a small field of view, and dozens of images were made into mosaics of the whole scene.

The scientists analyzed Huygens' speed, direction of motion, rotation and swinging during the descent. The movie includes sidebar graphics that show:
  • (Lower left corner) Huygens' trajectory views from the south, a scale bar for comparison to the height of Mount Everest, colored arrows that point to the sun and to the Cassini orbiter.
  • (Top left corner) A close-up view of the Huygens probe highlighting large and unexpected parachute movements, a scale bar for comparison to human height.
  • (Lower right corner) A compass that shows the changing direction of view as Huygens rotates, along with the relative positions of the sun and Cassini.
  • (Upper right corner) A clock that shows Universal Time for Jan. 14, 2005 (Universal Time is 7 hours ahead of Pacific Daylight Time). Above the clock, events are listed in mission time, which starts with the deployment of the first of the three parachutes.
Sounds from a left speaker trace Huygens' motion, with tones changing with rotational speed and the tilt of the parachute. There also are clicks that clock the rotational counter, as well as sounds for the probe's heat shield hitting Titan's atmosphere, parachute deployments, heat shield release, jettison of the camera cover and touchdown.

Sounds from a right speaker go with the Descent Imager/Spectral Radiometer activity. There's a continuous tone that represents the strength of Huygens' signal to Cassini. Then there are 13 different chimes - one for each of instrument's 13 different science parts - that keep time with flashing-white-dot exposure counters. During its descent, the Descent Imager/Spectral Radiometer took 3,500 exposures.


14MB QT Captioned movie
Quote:
A View from Huygens - Jan. 14, 2005

This movie was built with data collected during the 147-minute plunge through Titan's thick orange-brown atmosphere to a soft sandy riverbed by the European Space Agency's Huygens Descent Imager/Spectral Radiometer on Jan. 14, 2005,
In 4 minutes and 40 seconds, the movie shows what the probe 'saw' within the few hours of the descent and the landing. On approach, Titan appeared as just a little disk in the sky among the stars, but after landing, the probe's camera resolved little grains of sand millions of times smaller than Titan.

At first, the Huygens camera just saw fog over the distant surface. The fog started to clear only at about 60 kilometers (37 miles) altitude, making it possible to resolve surface features as large as 100 meters (328 feet). Only after landing could the probe's camera resolve the little grains of sand. The movie provides a glimpse of such a huge change of scale.

A music-only version of the video is available at: http://photojournal.jpl.nasa.gov/catalog/PIA08118.
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Moogs
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Join Date: May 2004
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2006-05-06, 09:41

The Titan QT sequence reminds me of the 60s acid-trip sci-fi movies, with all the funky sounds and graphics. Logan vs. Montag Part Deux
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