This image shows pole-facing gullies in a southern hemisphere crater. Gullies are young features that are widely thought to form from fluvial processes involving liquid water. These particular gullies have very fine channels, including some that intersect and overlap. This is evidence that multiple flow events occurred within the gullies.

The wavy, arcuate ridges at the bottom of the slope may have formed by gravity moving ice-rich material off the crater wall. The pitted texture of the crater floor suggests that volatiles (ices that easily turn into gas) escaped from the subsurface, causing the surrounding material to collapse and form small pits.

For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.