Estimated solar wind-implanted helium-3 distribution on the Moon

Among the solar wind-implanted volatiles present in the lunar regolith, He- 3 is possibly the most valuable resource because of its potential as a fusi on fuel. The abundance of He-3 in the lunar regolith at a given location de pends on surface maturity, the amount of solar wind fluence, and titanium c ontent, because ilmenite (FeTiO3) retains helium much better than other maj or lunar minerals. Surface maturity and TiO2 maps from Clementine multispec tral data sets are combined here with a solar wind fluence model to produce a He-3 abundance map of the Moon. Comparison of the predicted He-3 values to landing site observations shows good correlation. The highest He-3 abund ances occur in the farside maria (due to greater solar wind fluence receive d) and in higher TiO2 nearside mare regions.