This HiRISE image shows a sample of the variety and complexity of processes that may occur on the walls of Martian craters, well after the impact crater formed.

At the very top of the image is the high crater rim; at the bottom of the image is the crater's central peak - a dome of material rising above the surrounding crater floor uplifted during the impact event.

Reaching down the walls of the crater are windy and crooked troughs, or gullies. Some of these gullies may have formed with the help of liquid water, melted from ice or snowpack on the crater walls or from groundwater within the walls. Also notable is the long tongue-like lobe stretching down the middle of the image, with a darker, rounded snout, and prominent parallel grooves on its surface. These characteristics, together with faint cracks on its surface, suggest that this lobe may have formed by movement of ice-rich material from up on the crater wall down to the crater floor.

Because surface features on this lobe, as well as most gullies, do not appear sharp and pristine, and wind-blown dunes have blown up on the front snout of the lobe, and because there are several small craters on the lobe's surface, the movement of ice-rich material, and possibly water, have probably not occurred very recently.

This image forms a stereo pair with ESP_013871_1475.

Written by: Patrick Russell

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.