This image covers a portion of the rim of Holden crater, revealing breaches created when water over-topped the rim and incised a series of channels as it flowed down the crater wall. The water responsible for the channels was impounded outside of the rim of Holden in Uzboi Vallis. (Holden Crater itself is approximately 150 kilometers in diameter.)

Uzboi Vallis was interrupted when Holden crater formed and the rim formed an effective, temporary damn to flow farther to the north. Once the Uzboi basin filled, water began flowing into Holden again, creating a series of low fan-shaped deltas, alluvial deposits, and a shallow, but relatively short-lived lake.

The channels in this image were only active for a short time, as a channel just to the east cut quickly into the rim and became responsible for most of the drainage into the crater. The fact that most of the fan-shaped deltas radiate from the dominant channel to the east rather than those in this image supports this scenario.
Written by: John Grant

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.