Dark Side of Dione
The icy, cratered surface of Saturn's moon Dione shows more than just its sunlit side in these two processed versions of the same image.
The view at left, with only mild enhancement, shows a romantic crescent with large craters visible. The contrast in the version at the right has been greatly enhanced to show the side of Dione lit faintly by reflected light from Saturn. A similar phenomenon can be seen from Earth, when the Moon’s dark side is visible due to "earthshine." The crater at the top of the image appears to have a sunlit central peak in the enhanced view -- a common characteristic of craters on Dione as seen in Voyager images. Slight variations in brightness on the moon’s dark side hint at the bright curved linear streaks, seen by Voyager. These streaks are thought to be deposits of water ice.
The image was taken with the Cassini spacecraft narrow angle camera on July 2, 2004, from a distance of about 1.4 million kilometers (860,000 thousand miles) from Dione, at a Sun-Dione-spacecraft, or phase angle of about 119 degrees. The image scale is 8 kilometers (5 miles) per pixel. Dione's diameter is 1,118 kilometers (695 miles) across. The images have been magnified by a factor of two to aid visibility.
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 Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.
For more information, about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov
and the Cassini imaging team home page, http://ciclops.org
Credit: NASA/JPL/Space Science Institute
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