Scientists have cast doubt on a major part of the case for the Moon having once held abundant water. A US team studied a mineral called apatite, which is found in a variety of lunar rock types. Apatite, whose name comes from a Greek word meaning deceit, may have misled scientists into thinking the Moon is wetter that it actually is.
Lead author Jeremy Boyce said: "We thought we had a great indicator, but it turns out it’s not that reliable." Initial analysis of the lunar rocks brought back to Earth by the Apollo missions, suggested the Moon was "bone dry".
But in the last decade, studies of volcanic glasses and apatite in lunar rocks have revealed them to be hydrogen-rich, building a compelling case for significant water having been present on the Moon as different minerals crystallised from the cooling magma.