The floors of these craters contain very interesting and enigmatic materials which may contain shallow subsurface ground ice with varying amounts of a sediment covering (mantle). When ice is covered with a critical thickness of sediment it is actually insulated and can survive longer than cleaner exposed ice. The ablation and sublimation of the ice causes a chaotic topography to develop with high and low regions. This may explain the relief seen on the crater floors. The terrain outside of the craters appears muted because it is most likely mantled with a dusty icy covering. This region of Mars is located along the highland/lowland boundary dichotomy.

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.

Image information: VIS instrument. Latitude 35.1, Longitude 71 East (289 West). 19 meter/pixel resolution.