MYSTERIES OF THE PRESENT AND PAST: PROBING THE MOON WITH MINERAL SPECTROSCOPY (Invited Presentation)

Abundant samples are commonly acquired for field sites on Earth, but the Moon is the only extraterrestrial body for which a suite of well-documented natural samples (soils and rocks) are available to validate and test analyses of the surface obtained remotely. Although currently limited to only a few sites on the lunar nearside, the lunar samples continue to provide enormous insight into extraterrestrial material as instrumentation in Earth-based laboratories have steadily improved in both capabilities and precision. Through the last several decades the Moon has thus become a poster-child for remote compositional analyses with results largely derived from visible to near-infrared spectroscopy. Lunar data now include global coverage with extended visible multispectral imagery and first generation near-infrared imaging spectroscopy. The data paint a rich but highly incomplete story; they are limited in spatial and spectral resolution as well as spectral range and temporal coverage (needed for recent interest in volatile abundance and distribution). As with Earth geology, the more we learn about lunar rocks and soils in the laboratory and remotely, we recognize much more data and information is needed in order to unravel fundamental processes of geologic and compositional evolution. For the Moon this applies to issues that range from the molecular scale (such as space weathering and alteration in the lunar environment) and the rock scale (remote identification of a deep-seated rock type unseen in the samples, pink spinel anorthosite) to the scale of the crust-mantle boundary (possibly marked by Mg-pyroxene rather than olivine). There is much to do both in analyzing spectroscopic data currently available as well as focusing on and planning the next steps of highly relevant lunar exploration.