Clouds scoot across the Martian sky in a movie clip consisting of 10 frames taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander.
This clip accelerates the motion. The camera took these 10 frames over a 10-minute period from 2:52 p.m. to 3:02 p.m. local solar time at the Phoenix site during Sol 94 (Aug. 29), the 94th Martian day since landing.
Particles of water-ice make up these clouds, like ice-crystal cirrus clouds on Earth. Ice hazes have been common at the Phoenix site in recent days.
The clouds are a dramatic visualization of the Martian water cycle. The water vapor comes off the north pole during the peak of summer. The northern-Mars summer has just passed its peak water-vapor abundance at the Phoenix site. The atmospheric water is available to form into clouds, fog and frost, such as the lander has been observing recently.
[Image NASA/JPL-Caltech/University of Arizona/Texas A&M University]