This image covers where the southern branch of Shalbatana Vallis opens into Chryse Planitia, showing a variety of boulders that have moved down slope leaving tracks on the surface. These boulders may have been thrown out from low-energy secondary craters, or simply eroded out of the above rocky cliff.

In the subimage, the left frame shows boulders moving in two directions, indicating that they had different sources. The right frame shows a boulder about 4 meters in diameter in the bottom left, having left a track that begins in the upper right. This boulder rolled down the hill, appears to have jumped the crater, bounced a few times, and then rolled to a halt.

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.