Clouds over Vastitas Borealis - Sol 113 (GIF-Movie; credits: NASA)

Caption NASA:"This sequence combines 32 images of clouds moving Eastward across a Martian Horizon. The Surface Stereo Imager on NASA's Phoenix Mars Lander took this set of images on Sept. 18, 2008, during early afternoon hours of the 113th Martian Day of the Mission.

The view is toward the north. The actual elapsed time between the first image and the last image is nearly half an hour. The numbers inset at lower left are the elapsed time, in seconds, after the first image of the sequence. The particles in the clouds are water-ice, as in cirrus clouds on Earth".