Apollo 15 Glass Beads Reveal Water Hidden in the Moon’s Interior
Green volcanic-glass beads collected by Apollo 15 in 1971 later yielded hydrogen, providing the first clear evidence that water existed inside the Moon when those beads formed and challenging the long-held view of a completely dry Moon. Follow-up work, including Brown University research in 2008 and further analyses by 2011, found water concentrations in the beads comparable to some terrestrial basalts, implying the lunar mantle contains significant water and prompting revisions to theories about the Moon’s formation and volatile retention. NASA now recognizes water in multiple forms on the Moon, from permanently shadowed regions to sunlit areas, with the beads serving as an early key clue to the Moon’s hidden interior.
