Image link: http://mars.jpl.nasa.gov/gallery/polaricecaps/PIA03461.html

This picture shows both a visible and a thermal infrared image taken by the
thermal emission imaging system on NASA’s 2001 Mars Odyssey spacecraft on
November 2, 2001. The images were taken as part of the ongoing calibration
and testing of the camera system as the spacecraft orbited Mars on its 13th
revolution of the planet.

The visible wavelength image, shown on the right in black and white, was
obtained using one of the instrument’s five visible filters. The spacecraft
was approximately 22,000 kilometers (about 13,600 miles) above Mars looking
down toward the south pole when this image was acquired. It is late spring
in the martian southern hemisphere.

The thermal infrared image, center, shows the temperature of the surface in
color. The circular feature seen in blue is the extremely cold martian south
polar carbon dioxide ice cap. The instrument has measured a temperature of
minus 120 degrees Celsius (minus184 degrees Fahrenheit) on the south polar
ice cap. The polar cap is more than 900 kilometers (540 miles) in diameter
at this time.

The visible image shows additional details along the edge of the ice cap, as
well as atmospheric hazes near the cap. The view of the surface appears hazy
due to dust that still remains in the martian atmosphere from the massive
martian dust storms that have occurred over the past several months.

The infrared image covers a length of over 6,500 kilometers (3,900 miles)
spanning the planet from limb to limb, with a resolution of approximately
5.5 kilometers per picture element, or pixel, (3.4 miles per pixel) at the
point directly beneath the spacecraft. The visible image has a resolution of
approximately 1 kilometer per pixel (.6 miles per pixel) and covers an area
roughly the size of the states of Arizona and New Mexico combined.

NASA’s Jet Propulsion Laboratory, Pasadena, Calif. manages the 2001 Mars
Odyssey mission for NASA’s Office of Space Science, Washington D.C. The
thermal-emission imaging system was developed at Arizona State University,
Tempe, with Raytheon Santa Barbara Remote Sensing, Santa Barbara, Calif.
Lockheed Martin Astronautics, Denver, is the prime contractor for the
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/Jet Propulsion Laboratory/Arizona State University.