These Mars Odyssey images show the "White Rock" feature
on Mars in both infrared (left) and visible (right) wavelengths. The images
were acquired simultaneously on March 11, 2002. The box shows where
the visible image is located in the infrared image. "White Rock"
is the unofficial name for this unusual landform that was first observed
during the Mariner 9 mission in the early 1970's. The variations in
brightness in the infrared image are due to differences in surface
temperature, where dark is cool and bright is warm. The dramatic
differences between the infrared and visible views of White Rock are the
result of solar heating. The relatively bright surfaces observed at visible
wavelengths reflect more solar energy than the darker surfaces, allowing
them to stay cooler and thus they appear dark in the infrared image. The
new thermal emission imaging system data will help to address the long
standing question of whether the White Rock deposit was produced in an
ancient crater lake or by dry processes of volcanic or wind deposition. The
infrared image has a resolution of 100 meters (328 feet) per pixel and is 32
kilometers (20 miles) wide. The visible image has a resolution of 18 meters
per pixel and is approximately 18 kilometers (11 miles) wide. The images
are centered at 8.2 degrees south latitude and 24.9 degrees east longitude.
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 was developed by Arizona State University,
Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing.
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.
Credit: NASA/JPL/Arizona State University