Astronomers have been aware of water ice present in the Moon, but it had only ever been discovered in shadowed impact craters at its poles. NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) recent mission has now confirmed the presence of water molecules in sunlit parts of the Moon’s surface.
NASA researchers already have some ideas as to how that water might be getting made. It is possible for it to arrive on the micrometeorites that land on the lunar surface, protected from the harsh environment within pencil-sized beads of glass formed during the impact.
It could also be hydrogen, coming on solar wind reacts with oxygen-bearing minerals in the Moon’s regolith to create hydroxyl which is then bombarded with solar radiation to convert it into water.