CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Rhea 'Rev 143' Raw Preview #3

Rhea 'Rev 143' Raw Preview #3
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  This raw, unprocessed image of Rhea was taken on January 11, 2011 and received on Earth January 12, 2011. The camera was pointing toward Rhea at approximately 955 kilometers away, and the image was taken using the CL1 and CL2 filters. The image has not been validated or calibrated. A validated/calibrated image will be archived with the Planetary Data System in 2012.

The Cassini Solstice Mission is a joint United States and European endeavor. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini Solstice Mission visit, and

Credit: NASA/JPL/Space Science Institute
Released: January 12, 2011
Image/Caption Information

Alliance Member Comments
Mercury_3488 (Jan 31, 2011 at 12:52 PM):
Hi Dragon_of_Luck_Mah_Jonng1971.

I agree with you, many of those craters are very Mimas like. I still think that Rhea is very unevolved, one of the largest, in fact potetially the second largest unevolved object in the entire Solar System, only the Jupiter moon Callisto taking # 1 in that list.

The similar sized Uranus moons Titania & Oberon are certainly far more evolved than Rhea, Titania has huge graben, possible frosting & a large smoother region with smaller & softened craters & Oberon although cratered, shows signs of cryovolcanism with many craters having dark floors, at least on huge chasm, many craters appear 'softened' like Enceladus, Dione, Miranda, Ariel, Titania, Triton & Ganymede, worlds that have been & some may, in the case of Enceladus & Triton still are geologically active.

Rhea shows none of that, a surface that is practically craters on craters on craters. Some faulting is present, but how much of that is due to the Tirawa Basin forming event or other impacts, remains to be seen. Rhea is certainly a relic from the earliest days, much to tell us about the history of the Kronian system ,regarding the environment this far out from the Sun & cratering rates of the Kronian system from the period shortly after the formative period. Rhea is fascinating, not so much because of Rhea itself, but because of what Rhea can tell us about the history of the Kronian system as a whole. Iapetus is another moon interesting for the same reason, aside from the huge mountain ridge, little else appears to have happened there either, Mimas too. Rhea is extremely photogenic too. It's an amazing surface visually, craters of differing shapes & sizes, some regions eppear more hilly than others, etc.

Yes they are Cosmic Rays @ the lower left.

Andrew Brown.
Dragon_of_Luck_Mah_Jonng1971 (Jan 17, 2011 at 4:02 PM):
Those medium-sized deep craters remind me on Mimas.

( The two small short white lines at the lower left are cosmic ray hits I suppose.)
20tauri (Jan 12, 2011 at 9:37 PM):
Anaglyph, please!