Gullies on Gorgonum Chaos Mesas
NASA/JPL/University of Arizona
Gullies on Gorgonum Chaos Mesas
PSP_001948_1425  Science Theme: Fluvial Processes


800  1024  
1152  1280  
1440  1600  
1920  2048  


PDF, 11 x 17 in  
This observation shows part of Gorgonum Chaos, a large cluster of chaotic terrain found in the southern hemisphere.

Many regions of chaotic terrain are found at the head of large outflow channels that were scoured by ancient floods. Gorgonum Chaos is one region that is not associated with an outflow channel.

Chaotic terrain can form when subsurface volatiles (such as water) are catastrophically released and the overlying surface collapses. It is not known whether isolated chaotic terrain—such as that shown in this image—formed in the same way that the chaotic terrain near the outflow channels did. Wind erosion might play a role in their formation.

Gorgonum Chaos is an especially interesting area because gullies thought to have been eroded by liquid water are located on its mesas (see subimage). The gullies have a wide range of orientations and many appear to emanate from a distinct layer in the mesas (see subimage).

It is not known why gullies form on one slope rather than another, but insolation (amount of sunlight received), availability of water, and regional slope are possible contributing factors.

Written by: Kelly Kolb   (7 July 2010)

Click to share this post on Twitter Click to share this post on Facebook Click to share this post on Google+ Click to share this post on Tumblr

 Image Products: All image links are drag & drop for HiView, or click to download
B&W: map projected  non-map

IRB color: map projected  non-map

Merged IRB: map projected

Merged RGB: map projected

RGB color: non-map projected

B&W: map-projected (976MB)

IRB color: map-projected (414MB)
B&W: map-projected  (356MB),
non-map  (627MB)

IRB color: map projected  (131MB)
non-map  (488MB)

Merged IRB: map projected  (232MB)

Merged RGB: map-projected  (234MB)

RGB color: non map-projected  (447MB)
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

About color products (PDF)
HiView main page

 Observation Toolbox
Acquisition date:26 December 2006 Local Mars time:15:43
Latitude (centered):-37.052° Longitude (East):189.529°
Range to target site:254.9 km (159.3 miles)Original image scale range:25.5 cm/pixel (with 1 x 1 binning) so objects ~77 cm across are resolved
Map projected scale:25 cm/pixel and North is upMap projection:Equirectangular
Emission angle:3.7° Phase angle:73.5°
Solar incidence angle:70°, with the Sun about 20° above the horizon Solar longitude:156.4°, Northern Summer

Context map

Usage Policy
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: 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.