These are three different views of the Martian moon Phobos, as seen by NASA's 2001 Mars Odyssey orbiter using its infrared camera, Thermal Emission Imaging System (THEMIS). Each color represents a different temperature range.
The annotated version of this image labels each of these views with the dates when they were imaged by THEMIS. The two views on the left were taken while Phobos was in a half-moon phase, which is better for studying surface textures. The third, on the far-right, was taken in a full-moon phase, which is better for studying material composition.
A scale bar on the annotated image ranges from 150 to 300 degrees Kelvin, or -190 degrees Fahrenheit (-123 degrees Celsius) to 80 degrees Fahrenheit (27 degrees Celsius).
NASA's Jet Propulsion Laboratory in Pasadena, California, manages the 2001 Mars Odyssey mission for NASA's Science Mission Directorate in Washington. THEMIS was developed by Arizona State University in Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing.
The THEMIS investigation is led by Philip Christensen at ASU. The prime contractor for the Odyssey project, Lockheed Martin Space in Denver, developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of Caltech in Pasadena.