Clouds appear in the Martian sky above Endurance Crater in this mosaic of frames taken by the navigation camera on NASA's Rover Opportunity at about 9:30 a.m. on the rover's 290th sol (November 16, 2004). These clouds are part of a band that forms near the equator when Mars is near the part of its orbit that is farthest from the Sun. (Photo by AP Photo/NASA/JPL via The Atlantic)
