Status Report

Mars Odyssey THEMIS Image: Proctor Crater Dunes

By SpaceRef Editor
August 8, 2002
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Medium image for 20020808a

Image Context:
Context image for 20020808a
Context image credit: NASA/Mars Orbiter Laser Altimeter (MOLA) Team
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This image, located near 30E and 47.5S, displays sand dunes within Proctor
Crater. These dunes are composed of basaltic sand that has collected in the
bottom of the crater. The topographic depression of the crater forms a sand
trap that prevents the sand from escaping. Dune fields are common in the
bottoms of craters on Mars and appear as dark splotches that lean up against
the downwind walls of the craters. Dunes are useful for studying both the
geology and meteorology of Mars. The sand forms by erosion of larger rocks,
but it is unclear when and where this erosion took place on Mars or how such
large volumes of sand could be formed. The dunes also indicate the local wind
directions by their morphology. In this case, there are few clear slipfaces
that would indicate the downwind direction. The crests of the dunes also
typically run north-south in the image. This dune form indicates that there
are probably two prevailing wind directions that run east and west (left to
right and right to left).

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[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

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ParameterValue ParameterValue
Latitude-47.5 &nbsp InstrumentVIS
Longitude30.2E (329.8W) &nbsp Resolution (m)19
Image Size (pixels)3079×1163 &nbsp Image Size (km)58.5×22.1
Solar Longitude329.6 &nbsp Emission Angle2.9
Incidence Angle67.2 &nbsp Phase Angle69.2
North Azimuth262.9 &nbsp Slant Distance428.4 km
Local Solar Time8.8 &nbsp Sun Azimuth114.8

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