This image shows the landing site of NASA's Phoenix Mars Lander on the fourth Martian day of the mission, or Sol 4 (May 29, 2008). The image was taken by Phoenix's Robotic Arm Camera (RAC). As seen in the top center, the exhaust from the descent engine has blown soil off to reveal either rock or ice, which has not yet been determined.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.