Nirgal Vallis

Released 16 September 2003

Upper reaches of Nirgal Vallis. This valley network is one of the longest on Mars and this image captures the sapping morphology (alcoves, stubby tributaries) associated with this channel. However, it is not clear how this channel formed (ground water sapping vs rain/snowmelt surface runoff). The last geomorphic process to occur is the one best preserved but it should be noted that earlier processes may have been modified and or wiped out.

Image information: VIS instrument. Latitude -27.4, Longitude 314.4 East (45.6 West). 19 meter/pixel resolution.

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.