Today's Image of Mars is an animated clip showing clouds move across the Martian sky. These images were taken over the course of 10 minutes by the Surface Stereo imager of NASA's Phoenix Mars Lander. The motion in this clip has been accelerated to give a better idea of the motion between images.
This image of clouds on Mars was taken on the 94th sol (Aug 29 2008) of the Phoenix Lander mission.. These clouds are water vapor that comes off the north pole during the peak of summer when it is hottest.
Clicking on this image will take you to the original clip and associated article from NASA.