A recent study finds that the lake known as Ontario Lacus on Saturn's moon Titan (left) bears striking similarity to a salt pan on Earth known as the Etosha Pan (right). A salt pan is a lake bed that fills with a shallow layer of water from groundwater levels that rise during the rainy season. This layer then evaporates and leaves sediments like tide marks showing the previous extent of the water. Ontario Lacus, seen in an image obtained by the radar instrument aboard NASA's Cassini spacecraft on Jan. 12, 2010, covers an area about 140 by 47 miles (230 by 75 kilometers). The Etosha Pan, seen in an image obtained by a NASA and USGS Landsat satellite on Jan. 21, 2003, covers an area about 75 by 40 miles (120 by 65 kilometers). The north direction is indicated by the arrows.
Credit: NASA/JPL-Caltech and NASA/USGS