Gypsum, a common mineral composed of calcium sulfate, lies scattered in this newly-released image of the Olympia Undae region of Mars. The picture was made by combining CRISM data with HiRISE observations, and has the same resolution characteristics of the Nili Fossae image. Made on October 1, 2006, the image covers about 12 square kilometers (7.5 sq. mi.). Gypsum, used commonly on Earth as the substance in wallboard, is a sulfate-rich mineral that forms by evaporation and requires large amounts of water for its formation. In this image, brighter areas contain more gypsum and darker areas less so. The bottom views are enlargements of the central part of the two versions of the image shown at top. Could this large gypsum deposit be the dead mineral remains of a once mighty sea that occupied this area of the Red Planet?
NASA/JPL/JHUAPL/Brown University