On the Moon, areas of smooth plains are called "maria", plural of the Latin word "mare", for "sea". For example, Mare Imbrium is the Sea of Rains. After Mariner 10 obtained the first spacecraft images of Mercury in the mid-1970s, seven areas of smooth plains were given names. However, they were named "planitia", not "maria". Today's release is a mosaic of MESSENGER images centered on Suisei Planitia. Suisei is the Japanese word for the planet Mercury.
Release Date: November 12, 2012
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington