Widespread distribution of OH/H2O on the lunar surface inferred from spectral data

Remote-sensing data from lunar orbiters have revealed spectral features consistent with the presence of OH or H 2 O on the lunar surface. Analyses of data from the Moon Mineralogy Mapper spectrometer onboard the Chandrayaan-1 spacecraft have suggested that OH/H 2 O is recycled on diurnal timescales and persists only at high latitudes. However, the spatial distribution and temporal variability of the OH/H 2 O, as well as its source, remain uncertain. Here we incorporate a physics-based thermal correction into analysis of reflectance spectra from the Moon Mineralogy Mapper and find that prominent absorption features consistent with OH/H 2 O can be present at all latitudes, local times and surface types examined. This suggests the widespread presence of OH/H 2 O on the lunar surface without significant diurnal migration. We suggest that the spectra are consistent with the production of OH in space-weathered materials by the solar wind implantation of H + and formation of OH at crystal defect sites, as opposed to H 2 O sourced from the lunar interior. Regardless of the specific composition or formation mechanism, we conclude that OH/H 2 O can be present on the Moon under thermal conditions more wide-ranging than previously recognized. Hydroxyl produced by space weathering processes may be widespread and persistent on the lunar surface according to analysis of spectral data from the Chandrayaan-1 spacecraft.