This image shows an approximately 2-kilometer wide trough within Ladon Basin. This trough, and others around the perimeter of the basin, were probably produced during the gradual sinking of the materials here.
The basin formed during an epoch in Martian history called the Noachian period , and may have harbored a lake based upon the fluvial valleys that flow into it. If a lake once existed here then the trough is a window that could expose any sediments deposited within the lake, making this an exciting image to explore.
Written by: Cathy Weitz (audio by Tre Gibbs) (23 May 2012)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_026416_1620
Image: NASA/JPL/University of Arizona