Mars Odyssey THEMIS Image: Long-range view of Melas Chasma, Valles Marineris

This figure shows a mosaic of THEMIS day and night infrared images of Melas Chasma. The daytime temperature images are shown in black and white, superimposed on the martian topography. A single THEMIS nighttime temperature image is superimposed in color. The daytime temperatures range from approximately -35 deg C (black) to -5 deg C (white). Overlapping landslides and individual layers in the walls of Melas Chasma can be seen in this image. These slides flowed over 100 km across the floor of Melas Chasma, producing deposits with ridges and grooves of alternating warm and cold materials that can still be seen. The temperature differences in this image are due primarily to lighting effects, where sunlit slopes are warm (bright) and shadowed slopes are cool (dark). The nighttime temperature differences are due to differences in the abundance of rocky materials that retain their heat at night and stay relatively warm (red). Fine grained dust and sand (blue) cools off more rapidly at night. These images were acquired using the THEMIS infrared Band 9 centered at 12.6 µm.

[Source: ASU THEMIS Science Team]

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 Credit: NASA/JPL/Arizona State University