- Original Caption Released with Image:
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Released 15 March 2004
The Odyssey spacecraft has completed a full Mars year of observations of
the red planet. For the next several weeks the Image of the Day will look
back over this first mars year. It will focus on four themes: 1) the
poles - with the seasonal changes seen in the retreat and expansion of
the caps; 2) craters - with a variety of morphologies relating to impact
materials and later alteration, both infilling and exhumation; 3)
channels - the clues to liquid surface flow; and 4) volcanic flow
features. While some images have helped answer questions about the
history of Mars, many have raised new questions that are still being
investigated as Odyssey continues collecting data as it orbits Mars.
Infrared images taken during the nighttime exhibit only the
thermophysical properties of the surface of Mars. The effect of
sun-facing versus non-sun-facing energy dissipates quickly at night.
Thermophysical effects dominate as different surfaces cool at different
rates through the nighttime hours. Rocks cool slowly, and are therefore
relatively bright at night (remember that rocks are dark during the day).
Dust and other fine grained materials cool very quickly and are dark in
nighttime infrared images.
This nighttime IR image was collected September 28, 2002 during the
northern spring season. The "pinwheel" pattern represents alternating
warm and cool materials.
Image information: IR instrument. Latitude 60.3, Longitude 271.9
East (88.1 West). 100 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.
- Image Credit:
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NASA/JPL/Arizona State University
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