Polar Mesospheric Clouds on the Horizon* This video was taken by the crew of Expedition 31 on board the International Space Station. The sequence of shots was taken June 5, 2012 from 18:26:38 to 18:31:04 GMT, on a pass from western Iraq to western Uzbekistan. This video captures an atmospheric phenomenon called "Polar Mesospheric Clouds" (Click here to learn more about this type of cloud). By focusing on the limb of the Earth at night with the sun illuminating it, the crew was able to capture some movement to these mysterious clouds. Compiled from frames ISS031-E-97792 to ISS031-E-98058 Image courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center