The system of sinuous ridges seen at the top of the image is the remnants of a channel system. In this case the channel has been filled by a material more resistant to erosion than the surroundings. As the surround material was eroded away the resistant channel fill was left behind, forming a ridge where the channel had once been. This reversal of topography - from a channel to a ridge - is termed inversion or inverted topography.
Image information: VIS instrument. Latitude -6.5N, Longitude 151.3E. 18 meter/pixel resolution.
Please see the THEMIS Data Citation Note for details on crediting THEMIS images.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.