Remote sensing of potential lunar resources 1. Near-side compositional properties

New telescopic CCD multispectral imaging of the lunar near side and 330-870 nm spectroscopy of selected regions are presented as aids in estimating compositional differences relevant to locating potential lunar resources such as ilmenite (FeTiO₃) and solar wind-implanted ³He and H. Conversion of 400/560 nm CCD ratio images to weight percent TiO₂ using a version of the Charette et al. (1974) empirical relation allows construction of a new TiO₂ abundance map for the lunar maria accurate to +/-2 wt% TiO₂. This map provides a consistent view of TiO₂ distribution among mature mare soils and can be used to estimate areas potentially rich in ilmenite. Western Mare Tranquillitatis exhibits the highest TiO₂ abundances (>8 wt%), followed by regions near Flamsteed P and in northern Oceanus Procellarum. A 950/560 nm CCD ratio mosaic of the full Moon provides estimates of relative surface maturity on local scales as defined by the degree of agglutinate production due to micrometeorite impacts. Since high ³He concentrations are correlated with mature ilmenite-rich soils, a combination of relative surface maturity maps and TiO₂ abundance maps may be useful for estimating ³He (and possibly H) distribution on local scales. While dark mantle materials are also potential sources of ilmenite, ³He, and H, their compositional differences from mare soils prevent accurate remote mapping of their TiO₂ abundance and relative maturity. Reflectance spectra (relative to a more rigorously defined MS-2 standard region) of dark mantle materials and high-TiO₂ mare areas exhibit previously documented near-UV (<350 nm) changes in spectral slope apparently related to compositional variations. Determination of the primary lunar sites for resource utilization will be dictated by the future goals and priorities of the lunar resource progam.