lunar water

These false-color images show areas where water presence is indicated in a young lunar crater on the far side, as imaged by the Moon Mineralogy Mapper aboard Chandrayaan-1. The image shows the distribution of surface ice at the Moon's south pole (left) and north pole (right) as viewed by NASA's Moon Mineralogy Mapper (M) spectrometer onboard India's Chandrayaan-1 orbiter The search for the presence of lunar water has attracted considerable attention and motivated several recent lunar missions, largely because of water's usefulness in making long-term lunar habitation feasible.

The Moon is believed to be generally anhydrous after analysis of Apollo mission soil samples. It is understood that any water vapor on the surface would generally be decomposed by sunlight, leaving hydrogen and oxygen lost to outer space. However, subsequent robotic probes found evidence of water, especially of water ice in some permanently shadowed craters on the Moon. In 2018 water ice was confirmed in multiple locations. This water ice is not in the form of sheets of ice on the surface nor just under the surface, but there may be small (less than about 10 centimetres (3.9 in)) chunks of ice mixed into the regolith, and some water is chemically bonded with minerals. Other experiments have detected water molecules in the negligible lunar atmosphere, and even some in low concentrations at the Moon's sunlit surface.