Matthew R.M. Izawa^a, Edward A. Cloutis^a, Daniel M. Applin^a, Michael A. Craig^b, Paul Mann^a and Matthew Cuddy^a

^aHyperspectral Optical Sensing for Extraterrestrial Reconnaissance Laboratory, Dept. Geography, University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba R3B 2E9, Canada
^bDepartment of Earth Sciences/Centre for Planetary Science and Exploration, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada

Reflectance spectroscopy of Apollo lunar soil samples curated in an air- and water-free, sealed environment since recovery and return to Earth has been carried out under water-, oxygen-, CO₂– and organic-controlled conditions. Spectra of these pristine samples contain features near 3 μm wavelength similar to those observed from the lunar surface by the Chandrayaan-1 Moon Mineralogy Mapper (M³), Cassini Visual and Infrared Mapping Spectrometer (VIMS), and Deep Impact Extrasolar Planet Observation and Deep Impact Extended Investigation (EPOXI) High-Resolution Instrument (HRI) instruments. Spectral feature characteristics and inferred OH/H₂O concentrations are within the range of those observed by spacecraft instruments. These findings confirm that the 3 μm feature from the lunar surface results from the presence of hydration in the form of bound OH and H₂O. Implantation of solar wind H⁺ appears to be the most plausible formation mechanism for most of the observed lunar OH and H₂O.

Reference
Izawa MRM, Cloutis EA, Applin DM, Craig MA, Mann P and Cuddy M (2014) Laboratory spectroscopic detection of hydration in pristine lunar regolith. Earth and Planetary Science Letters 390:157–164.
[doi:10.1016/j.epsl.2014.01.007]
Copyright Elsevier

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