This image shows portions of the northwest and southwest rims of a northern hemisphere crater. The northwest rim has gullies, features frequently proposed to be carved by fluvial processes or debris flows.

The dark material on the crater floor is dust; some if it has been moved by dust devils to form the dark streaks visible here.

The scene has two main textures: smooth and pitted. The smooth, mantling material is thought to be ice-rich. The pitted regions are thought to mark locations where the subsurface ice has been removed by sublimation, when ices convert directly to gas.

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.