The vast expanse of the crater Odysseus
spreads out below Cassini in this mosaic view of Saturn's moon Tethys.
The crater (450 kilometers or 280 miles across) is a remarkably well-preserved example of an ancient multi-ringed impact basin: The outer ring is defined by steep, cliff-like walls that descend to generally broad internal terraces. The inner ring is formed by a prominent, crown-shaped, 140-kilometer (88-mile) diameter circular band of icy mountains. Multi-ring basins are seen on rocky bodies as well as icy ones.
The complex internal structure and multi-ringed nature of these very large basins are believed to arise from the rebound of intense shock waves that penetrated the body at the time of impact.
Tethys is 1,071 kilometers (665 miles) across.
This mosaic was assembled from four clear filter, narrow-angle camera images. The view is an orthographic projection centered on 3 degrees south latitude, 119 degrees west longitude and has a resolution of 572 meters (0.35 mile) per pixel. An orthographic view is most like the view seen by a distant observer looking through a telescope. North is up.
The view was obtained by the Cassini spacecraft on Aug. 30, 2007, from a distance of approximately 97,000 kilometers (60,000 miles) and at a sun-Tethys-spacecraft, or phase, angle of 51 degrees.
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 operations center is based at the Space Science Institute in Boulder, Colo.
Credit: NASA/JPL/Space Science Institute