This crater shows prominent gullies on it walls. The origin of gullies is controversial, but many, and probably those here, seem to require carbon dioxide or water frost that may fluidize debris flows,or possibly water in an ephemeral (short term) stability state that erodes the surface.
This region is being continually monitored by HiRISE to note any changes.
Written by: HiRISE Science Team (21 September 2011)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_023322_1390
Image: NASA/JPL/University of Arizona