Mercury is the innermost planet in the Solar System. It is right next door to the very hot sun. Water boils and evaporates very easily so how much water could possible be on this very hot planet? Instruments aboard NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft studying the planet Mercury have provided compelling support for the long-held hypothesis the planet harbors abundant water ice and other frozen volatile materials within its permanently shadowed polar craters...