"When we say 'water on the moon,' we are not talking about lakes, oceans or even puddles," according to Brown University researcher Carle Pieters.  "Water on the moon means molecules of water and hydroxyl (hydrogen and oxygen) that interact with molecules of rock and dust specifically in the top millimeters of the moon's surface."

Specifically, the NASA Cassini and Deep Impact spacecraft, along with India's Chandrayaan-1, collected the most recent data.  During the Apollo missions -- which took place in the 1960s and 1970s – NASA retrieved several rocks that contained minute amounts of trapped water, but the small traces were believed to be contamination from Earth.

Researchers previously believed the moon was a completely dry place, even though the dark side of the moon is cold enough to support ice.  Once the dark side passes into the sunlight, however, the ice would end up evaporating quickly.  It was previously believed there could be liquid water found at the moon's poles, but there could be much wetter areas at several select locations away from the poles.

Researchers from the University of Maryland, Brown University, U.S. Geological Survey, and international scientists are looking into other places that could be wet.  Water is important as space nations show continued interest in lunar bases -- though transporting water and supplies are major issues -- but the ability to filter water and grow crops would make it even more feasible to survive on the moon.