This image shows high latitude terrain near the Sisyphi Montes. Patterned ground is everywhere throughout the scene, and there are several muted craters that have relaxed over time due to the presence of ground ice.

Dark splotches are also common. Using full HiRISE resolution, the dark splotches exist around boulders. It is possible that the boulders are ejecta from the freshest crater in the scene, the small crater near the top of the image. They could also be from another impact crater not in this image or be a result of a periglacial stone sorting process that leaves the large boulders isolated.

Written by: Kelly Kolb

All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible: Image: NASA/JPL/University of Arizona

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.