Detection of Adsorbed Water and Hydroxyl on the Moon

• Published in: Science (American Association for the Advancement of Science) Vol. 326; no. 5952; pp. 562 - 564
• Main Author: Clark, Roger N
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 23.10.2009; The American Association for the Advancement of Science
• Subjects: Absorption spectra; Adsorption; Astronomy; Earth, ocean, space; Earths Moon; Exact sciences and technology; Extraterrestrial Environment; Features, landmarks, mineralogy, petrology, and atmosphere; Hydrogen; Hydroxyl Radical; Hydroxyls; Lunar soil; Minerals; Moon; Polar regions; Soil water; Solar system; Space exploration; Spacecraft; Spectral reflectance; Spectrum Analysis; Sunlight; Temperature; Thermal radiation; Water; Water; Grain size; Mixing; Moon; Adsorbed state; Hydroxyl radicals; Cassini space probe
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1178105

Data from the Visual and Infrared Mapping Spectrometer (VIMS) on Cassini during its flyby of the Moon in 1999 show a broad absorption at 3 micrometers due to adsorbed water and near 2.8 micrometers attributed to hydroxyl in the sunlit surface on the Moon. The amounts of water indicated in the spectra depend on the type of mixing and the grain sizes in the rocks and soils but could be 10 to 1000 parts per million and locally higher. Water in the polar regions may be water that has migrated to the colder environments there. Trace hydroxyl is observed in the anorthositic highlands at lower latitudes.