Illuminating Shadows in Gorgonum Chaos
Highlighted Portion of HiRISE Image TRA_000866_1420This HiRISE image [below] shows cratered plains along the edge of a large fracture to the south of Gorgonum Chaos. The wall of the fracture is in shadow and, at first glance, appears to reveal little detail about the geologic setting. In reality, the high quality of the HiRISE image, as shown in the stretched sub-image [above], demonstrates that considerable detail along the wall of the fracture can be discerned. A relatively dark layer extends along the upper wall of the fracture and approximately separates the exposed wall above from talus below. Some well defined talus chutes are also visible and are formed by the down slope movement of debris shed from higher along the fracture wall. The wind blown drifts of fine grained sediment accumulated along the base of the talus slope are relatively free of obvious talus. Hence, the wind likely accounts for much of the most recent modification of the scene in the sub image.
Image TRA_000866_1420 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on October 2, 2006. The complete image is centered at -37.6 degrees latitude, 190.3 degrees East longitude. The range to the target site was 252.6 km (157.9 miles). At this distance the image scale is 50.5 cm/pixel (with 2 x 2 binning) so objects ~152 cm across are resolved. The image shown here [below] has been map-projected to 50 cm/pixel and north is up. The image was taken at a local Mars time of 3:35 PM and the scene is illuminated from the west with a solar incidence angle of 79 degrees, thus the sun was about 11 degrees above the horizon. At a solar longitude of 115.1 degrees, the season on Mars is Northern Summer.
HiRISE Image TRA_000866_1420
Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at:
http://hirise.lpl.arizona.edu/
or
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, 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.
