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.
Photo credit: NASA/JPL/University of Arizona
Note: Ladon Basin is not a formally named feature on Mars; however, it is located in southwestern Margaritifer Terra. Ladon Valles (the only Martian feature with the Ladon name) looks to have flowed north into the southern end of the impact basin; however, this trough is far to the northwest of that outflow channel.