The Surface Stereo Imager on NASA's Phoenix Mars Lander caught this dust devil in action west-southwest of the lander at 11:16 a.m. local Mars time on Sol 104, or the 104th Martian day of the mission, Sept. 9, 2008.
Dust devils have not been detected in any Phoenix images from earlier in the mission, but at least six were observed in a dozen images taken on Sol 104.
Dust devils are whirlwinds that often occur when the Sun heats the surface of Mars, or some areas on Earth. The warmed surface heats the layer of atmosphere closest to it, and the warm air rises in a whirling motion, stirring dust up from the surface like a miniature tornado.
The vertical post near the left edge of this image is the mast of the Meteorological Station on Phoenix. The dust devil visible at the horizon just to the right of the mast is estimated to be 600 to 700 meters (about 2,000 to 2,300 feet) from Phoenix, and 4 to 5 meters (10 to 13 feet) in diameter. It is much smaller than dust devils that have been observed by NASA's Mars Exploration Rover Spirit much closer to the equator. It is closer in size to dust devils seen from orbit in the Phoenix landing region, though still smaller than those.
The image has been enhanced to make the dust devil easier to see.
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.
Image NASA/JPL-Caltech/University of Arizona/Texas A&M University