Terby Crater is a large (diameter ~165 km), Noachian-aged crater located on the northern rim of the Hellas impact basin (28ºS, 74.1ºE).

Terby hosts a very impressive sequence of predominantly light-toned layered deposits, up to 2.5 km thick that are banked along its northern rim and extend toward the center of the crater.

HiRISE image PSP_001662_1520 (1.4 MB) shows this stack of layered rocks as they are exposed westward facing scarp. The layered sequence consists of many beds that are repetitive, relatively horizontal and laterally continuous on a kilometer scale. Many beds are strongly jointed and fractured and exhibit evidence of small-scale wind scour.

The light-toned layers are typically at least partially covered with dark mantling material that obscures the layers as well as debris and numerous, meter-scale boulders that have cascaded down slope. The processes responsible for formation of these layers remain a mystery, but could include deposition in water, by the wind, or even volcanic activity.

This HiRISE image is a proposed landing site for the Mars Science Laboratory (MSL) in Terby Crater.
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.