Possibility of the presence of S, SO2, and CO2 at the poles of the moon

The presence of volatiles near the lunar poles is considered. The chemical composition of a lunar atmosphere temporarily produced by comet impact is analyzed during the day and night. C-rich and long-period comets are insufficient sources of water ice on the Moon. O-rich short-period cornets deliver significant amounts of H2O, CO2 SO2, and S to the Moon. An observable amount of polar hydrogen can be delivered to the Moon by a single impact of all O-rich short-period comet with diameter of 5 kin in the form of water ice. The areas where CO2 and SO2 ices are stable against a thermal sublimation are estimated to be around 300 and 1500 km(2,) respectively. If water ice exists in 2 cm top regolith layer, CO2 and SO2 ices can be stable in the coldest parts of permanently shaded craters. The delivery rate of elemental Sulfur near the poles is estimated to be 10(6) gyr(-1). The sulfur content is estimated to be as 41 high as 1 wt% in the polar regions. The SELENE gamma-ray spectrometer can detect sulfur polar caps oil the Moon if the sulfur Content is higher than 1 wt %. This instrument can check the presence of hydrogen and minerals with the unusual chemical composition at the lunar poles.