Status Report

Mars Odyssey THEMIS Image: Frosted Sand Dunes

By SpaceRef Editor

July 22, 2002

Filed under Daily Themis Pictures, Mars Odyssey THEMIS, US

Image Context:

Context image credit: NASA/Mars Orbiter Laser Altimeter (MOLA) Team

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This image, located near 79.6 N and 142.7 E, displays sand dunes covered in CO2
frost. This is a region of Mars that contains circumpolar sand seas. The
large sand deposits and the high winds that circulate around the pole allow for
the formation of a huge dune field that surrounds the north polar cap. As the
northern hemisphere progresses towards winter, CO2 frost condenses out of the
atmosphere and covers the dunes. During northern spring, the CO2 sublimates
and the dunes are once again uncovered and active. This image was taken as
northern spring progresses and the crests of the dunes are just starting to be
exposed. The dark dune material absorbs sunlight more efficiently than the
brighter frost, aiding in the sublimation of the remaining frost.

[Source: ASU THEMIS Science Team]

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 Credit: NASA/JPL/Arizona State University