CICLOPS: Cassini Imaging Central Laboratory for OPerationS

A Stressed Surface
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This southerly view of Dione shows enormous canyons extending from mid-latitudes on the trailing hemisphere, at right, to the the moon's south polar region.

This view looks toward the Saturn-facing side of Dione (1,123 kilometers, 698 miles across) and is centered on 22 degrees south latitude, 359 degrees west longitude. North on Dione is up; the moon's south pole is seen at bottom.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 8, 2008. The view was obtained at a distance of approximately 211,000 kilometers (131,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 20 degrees. Image scale is 1 kilometer (0.6 mile) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, 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 Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. 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-Huygens mission, visit and the Cassini imaging team home page,

Credit: NASA/JPL/Space Science Institute
Released: March 19, 2008 (PIA 09861)
Image/Caption Information
  A Stressed Surface
PIA 09861

Avg Rating: 8.49/10

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Alliance Member Comments
Red_dragon (Mar 19, 2008 at 8:22 AM):
I agree with 3488. A quite nice image of Dione.

(PS: R.I.P. A.C.Clarke, and thank you for writing that superb novel that is "2001" as well as "Rendezvous with Rama". May everywhere you're now you can continue following the discoveries coming from the Saturnian system)
Mercury_3488 (Mar 19, 2008 at 7:51 AM):
Very nice image of the large ice moon Dione.

Like Enceladus, Dione is the scene of very many differing processes. The wide deep Graben at the bottom of the image, do seem to be the result of internal geological activity, not impact related.

Did the ice mantle expand slightly here, causing the brittle ice crust above to crack? Perhaps future encounters with Cassini or a future Saturn, Titan, Enceladus spacecraft could swing by to take a look, will reveal cryolava flows on the floors, or the floors have just sunk (more likely).

The surface between the Graben & the terminator at the 4 to 5 O clock positions appears much smoother & less cratered then much of the rest of the hemisphere visible here. Perhaps cryovolcanic resurfacing, maybe related to the Graben?

The bright streaks coming from the 10 O'Clock position, does look like impact ejecta, coming from a point over the limb.

Dione is certainly one of Saturn's most interesting moons.

Andrew Brown.