This image shows an apparent valley north of a 37-kilometer long pit called Ophir Cavus.This valley is just west of another 155-km long valley system called Allegheny Vallis that also emanates from the pit.

The association of valleys with the pit suggests that water was released when the pit formed, perhaps when volcanic eruptions melted ice in the surface or subsurface. The HiRISE image reveals light-toned units along portions of the plains and these could be minerals deposited by the flowing water or alteration of the plains by the water that once flowed here.
Written by: Cathy

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.