Arsia Mons is the southernmost of the Tharsis volcanoes. It is 270 miles in diameter, almost 12 miles high, and the summit caldera is 72 miles wide. For comparison, the largest volcano on Earth is Mauna Loa. From its base on the sea floor, Mauna Loa measures only 6.3 miles high and 75 miles in diameter. The image here is a mosaic of several daytime IR images. The indentations on the SW and NE sides align with the Pavonis Mons and Ascreaus Mons to the NE. This may indicate a large fracture/vent system was responsible for the eruptions that formed all three volcanoes.

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.