CICLOPS: Cassini Imaging Central Laboratory for OPerationS

Wisps Before Craters
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Saturn's "wispy" moon Dione lies in front of the cratered surface of the moon Tethys, as seen by Cassini.

Dione is closest to the spacecraft here. At the top of the image, the bright "wispy" fractures are visible on Dione (1123 kilometers, 698 miles across). See PIA10560 and PIA06163 to learn more. Beyond wispy Dione, the large crater Penelope can be seen near the equator of Tethys (1062 kilometers, 660 miles across). See PIA08149 for a closer view of Penelope.

Lit terrain seen here is on the trailing hemispheres of the two moons. The image was taken in visible red light with the Cassini spacecraft narrow-angle camera on Dec. 6, 2010.

The view was obtained at a distance of approximately 2.1 million kilometers (1.3 million miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 75 degrees.
The view was obtained at a distance of approximately 2.2 million kilometers (1.4 million miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 75 degrees. Scale in the original image was 12 kilometers (8 miles) per pixel on Dione and 13 kilometers (8 miles) per pixel on Tethys. The image was contrast enhanced and magnified by a factor of two to enhance the visibility of surface features.

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 31, 2011 (PIA 12751)
Image/Caption Information
  Wisps Before Craters
PIA 12751

Avg Rating: 9.25/10

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Alliance Member Comments
Mercury_3488 (Jan 31, 2011 at 1:08 PM):

Just to say that around perikrone today, there was a non targetted Mimas pass, as well as that of Enceladus & Helene shortly after. Looking forward to seeing those images, Cassini did not pass that close to any of them, but more than close enough to reveal much new data & views from differing vantage points, than ever before.

Andrew Brown.
Mercury_3488 (Jan 31, 2011 at 1:02 PM):
Absolutely, fantastic image. Also because their distances from Cassini were not that much different, the small difference in size is apparent. Dione @ 1,123 KM wide & Tethys @ 1,063 KM wide. Mind you Dione has nearly twice the mass of Tethys due to it's much greater density & also Tethys appears unevolved & primitive, where as Dione has certainly seen much geological activity in the relatively 'recent' past & may still be active on a small scale.

Andrew Brown.
NeKto (Jan 31, 2011 at 11:47 AM):
What did i just say about science and artistic comosition?
here is another great example.

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