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Fraser
2006-May-04, 05:39 PM
SUMMARY: Cassini recently swept past two previously unexplored regions of Titan, and returned radar images of its surface. Cassini made its flyby on April 30, targeting the Xanadu region - one of the most prominent features on Titan, which is even visible from Earth. It revealed strange curving features that could indicate flowing fluids. There are also two large craters that could be from meteor impacts or volcanic calderas. This was Cassini's 14th Titan flyby, with the next on May 20.

View full article (http://www.universetoday.com/am/publish/3-5_saturn_titan_flyby.html)
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Blob
2006-May-04, 06:57 PM
Hum,
and incidentally,
Scientists at the University of Arizona Lunar and Planetary Laboratory (LPL) have released two new movies of the Huygens probe's landing on Saturn's giant moon, Titan, on Jan. 14, 2005.

The movies were made from images taken by Huygens' Descent Imager/Spectral Radiometer (DISR) during its 147-minute plunge through Titan's thick orange-brown atmosphere to a soft sandy riverbed. They are the most realistic way yet to experience the far-out-world landing.
These represent the best visual product from the mission obtained so far and the most realistic way yet to experience the landing on a far-away world.
The movie ‘View from Huygens on 14 January 2005’ shows in 4 minutes 40 seconds what the probe actually ‘saw’ within the few hours of the descent and the eventual landing.

Play .mov (http://www.nasa.gov/mov/148081main_PIA08117%20-%20Titan%20Data%20Movie%20320x240%20streaming.mov) (11mb)

The second, more technical movie (called ‘DISR movie’), shows DISR's 4-hour operating life in less than five minutes, too. A detailed caption to explain how the movie is structured is provided with the video.

Read more (http://www.lpl.arizona.edu/DISR/)

Blob
2006-May-04, 07:05 PM
Hum,
and here is another image of Saturn's moon Titan from the Synthetic Aperture Radar instrument which shows the southwestern area of a feature called Xanadu (bottom right of the image). The area is bright because it reflects the radio wavelengths used to make this radar images.

http://static.flickr.com/51/139991914_5fe392c01c_m.jpg
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Image credit: NASA/JPL/SSI

The radar image reveals details previously unseen, such as numerous curvy features that may indicate fluid flows. Linear dark streaks visible in radar-dark areas are dune fields, also seen in previous radar images.
Near the centre of the image is a prominent circular feature, named Guabonito, about 90 kilometres in diameter. It might be an impact crater or a cryovolcanic caldera. If this is an impact structure, the absence of an ejecta blanket suggests that the feature has been highly eroded, like some impact structures on Earth, or has been buried by the dune fields. Other radar-bright areas (top left and top right) appear to be topographically high and might act as obstacles, diverting the dunes around them.

Blob
2006-May-05, 01:01 AM
The Cassini space probe has seen sand dunes on Saturn's giant moon Titan. The bright features in the radar photo are not clouds but topographic features among the dunes

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Credit: NASA/JPL

The images taken when the Cassini spacecraft flew by Titan last October show dunes 100 meters high that run parallel to each other for hundreds of miles at Titan's equator. One dune field runs more than 1500 km long.
How the sand formed is a puzzle.
Sand may have formed when liquid methane rain eroded particles from ice bedrock. Researchers had previously thought that it doesn't rain enough on Titan to erode much bedrock.

The sand dunes are sculpted like Namibian sand dunes on Earth.

http://www.lpl.arizona.edu/~rlorenz/

Read more (http://uanews.org/cgi-bin/WebObjects/UANews.woa/2/wa/SRStoryDetails?ArticleID=12614)

Maksutov
2006-May-05, 05:53 AM
Beautiful photographs, what? Calderas, sand dunes, just about everything except Sirens... ;)

antoniseb
2006-May-05, 01:20 PM
Beautiful photographs, what? Calderas, sand dunes, just about everything except Sirens... ;)

They're saving the Sirens for the extended mission, right after finding the monolith on Iapetus.

Blob
2006-May-05, 10:34 PM
This image from the Synthetic Aperture Radar instrument on the Cassini spacecraft shows the radar-bright western margin of Xanadu, one of the most prominent features on Titan. In radar images, bright regions indicate a rough or scattering material, while a dark region might be smoother or more absorbing.

The image was taken during a flyby of Titan on April 30, 2006.

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Narrow, sinuous, radar-bright channels, meandering like a maze, are seen on the right-hand-side of the image. These may be river networks that might have flowed onto the dark areas on the left of the image.
Vast, dark areas covered by dunes are seen on the equatorial regions of Titan and have been referred to as Titan's "sand seas". Near the middle of the image is a radar-bright area that has a boundary with the dark sand seas. Because the radar illumination is coming from the top, this indicates that the bright region, Xanadu, is topographically higher than the sand seas.

Blob
2006-May-06, 10:39 AM
This image from the Synthetic Aperture Radar instrument on the Cassini spacecraft shows the radar-bright region Xanadu and two circular features interpreted to be degraded impact craters. In radar images, bright regions indicate a rough or scattering material, while a dark region might be smoother or more absorbing.
The image was acquired during a flyby of Titan on April 30, 2006.

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Credit: NASA/JPL

Near the top of the image is a 70-kilometer-wide impact structure. In contrast to a similarly sized crater called Sinlap, this crater shows a prominent central peak, indicating that the interaction between the impact and the crust was different in this region.
Near the bottom of the image is another circular feature with a dark central region that does not show evidence of a central peak. Numerous radar-bright channels cut across the image, indicating that liquids have flowed in this region.