Released 18 December 2003

Asymmetric craters such as the one in the center of this image are fairly rare. The more typical symmetric craters are formed when meteors impact a surface over a wide range of angles. Only very low impact angles (within 15° of horizontal) result in asymmetric structures such as this one. The bilateral symmetry of the ejecta, like two wings on either side of the elliptical crater, is typical of oblique impacts. The small crater downrange from the main crater could have been caused by the impactor breaking apart before impact or possibly a 'decapitation' of the impactor as it hit with the 'head' traveling farther to form the smaller structure.

Image information: VIS instrument. Latitude -8.5, Longitude 227.5 East (132.5 West). 19 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.