Mineralogical Characterization of Lunar Highland Soils

Introduction: It has been theorized that the effects of space weathering during soil formation on the Moon are similar to those for many other airless bodies (e.g., Vesta, Eros) [1,2]. Therefore, the study of these effects on lunar soils may form the basis for our understanding of other heavenly bodies. This is a particularly valid axiom for reflectance spectroscopy of these soils. It has been repeatedly demonstrated that it is the fine fractions that dominate the spectral reflectance signatures of lunar soils [3-4], and it is the 10-20 μm size fraction that has overall spectral properties most similar to the bulk soil. However, it is these same fractions that contain the major effects of space weathering, e.g., nanophase Fe, that create the overall spectral reddening, lowered albedo, and attenuated absorption features of the observed spectra. In order to attempt to unravel these effects on lunar spectra, the Lunar Soil Characterization Consortium (LSCC) was established [5] for the collaborative study of lunar soils by various techniques, all related to the quantification of space weathering effects and the deciphering these effects in reflectance spectra.