Io Transit of Jupiter The three snapshots of the volcanic moon rounding Jupiter were taken over a 1.8-hour time span. Io is roughly the size of Earth's moon but 2,000 times farther away. J.Spencer(Lowell Observatory) NASA/ESA
The spectacular rings of Saturn cast dark shadows on the ringed planet as the winter season approaches in Saturn's southern hemisphere in this view from the Cassini spacecraft. With the cold season comes a blue hue on Saturn that is likely caused by a drop in ultraviolet sunlight and haze it produces. This image was taken on July 29, 2013 and released on Dec. 23.
Sand ridges, 200 miles directly above the Martian surface. This image was taken by the Mars Reconnaissance Orbiter on Jan. 27, 2010. The black spidery flecks dotting the ridges, mostly on the sunny side, appear every spring and disappear every winter. Michael Benson/ NASA/JPL/ University of Arizona/Kinetikon Pictures