Samples from Tranquility Base suggest solar wind brings water to
lunar soil. Photo Credit: NASA The solar wind is a likely
contributor to widespread surface level water deposits in lunar
soil churned by micrometeoroid impacts over billions of years,
according to an analysis of tiny glass-like features called
agglutinates extracted from samples of the moon gathered by the
Apollo 11, 16 and 17 astronauts. A similar process could be at
work on other airless solar system bodies, including Mercury and
the large main belt asteroid Vesta, according to the study
"Direct Measurement of Hydroxyl in the Lunar Regolith and the
Origin of Lunar Surface Water" led by geologist Yang Liu, of the
University of Tennessee, Knoxville, and published Oct. 14 in the
journal Nature Geoscience. "Because agglutinates make up a major
proportion of lunar soils, often reaching 50% volume of a mature
soil, the detected OH in agglutinates represents an
unanticipated, abundant reservoir of OH/H2O in lunar regolith,"
according to the research