Features on the surface of Saturn's moon Rhea reveal clues about the moon's history. In this Cassini image, two large impact basins near center and bottom exhibit central peaks. The image shows largely the trailing hemisphere of Rhea. At right, some of the wispy markings that cover the moon's trailing hemisphere are visible. Rhea's diameter is 1,528 kilometers (949 miles) across.
The image was taken in visible light with the Cassini spacecraft narrow angle camera on Dec. 9, 2004, at a distance of 2.5 million kilometers (1.6 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 62 degrees. The image scale is about 15 kilometers (9 miles) per pixel. The image has been magnified by a factor of two and contrast enhanced 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 mission for NASA's Science Mission Directorate, 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.