FLUXES OF FAST AND EPITHERMAL NEUTRONS FROM LUNAR PROSPECTOR - EVIDENCE FOR WATER ICE AT THE LUNAR POLES

Maps of epithermal- and fast-neutron fluxes measured by Lunar Prospect or were used to search for deposits enriched in hydrogen at both lunar poles. Depressions in epithermal fluxes were observed close to perman ently shaded areas at both poles. The peak depression at the North Pol e is 4.6 percent below the average epithermal flux intensity at Lower latitudes, and that at the South Pole is 3.0 percent below the Low-Lat itude average. No measurable depression in fast neutrons is seen at ei ther pole. These data are consistent with deposits of hydrogen in the form of water ice that are covered by as much as 40 centimeters of des iccated regolith within permanently shaded craters near both poles.