9:45 AM - 10:00 AM
[PPS06-04] Sublimation of lunar water observed by SELENE over global shadowed regions
Keywords:Moon, Water, Near-infrared spectrum
Water on the Moon holds a key to understanding the origin of water for the Earth–Moon system. Recently, water has been identified in low and middle latitude regions in addition to the polar regions, by previous studies analyzing the Moon Mineralogy Mapper data. It has been also observed that the majority of water in the low and middle latitude regions changes in content during a lunar day; the water content around noon is lower than that around morning and evening. This result suggested that the water for the low and middle latitude regions is mainly the solar-wind derived water bounded weakly to the lunar surface and that the water experiences sublimation and deposition during a lunar day.
We analyzed near-infrared spectral data obtained by Spectral Profiler (SP) onboard SELENE, for shadowed regions over the lunar surface. The SP is a line-profiling spectrometer, which obtained the high wavelength resolution spectral data covering 500–2600 nm.
We re-calculated the reflectance for the shadowed regions, assuming that the incident light is not solar light but the light scattered on the surface of neighboring sun-lit regions. As results, we obtained spectrum features similar to water vapor for some of the shadowed regions, which might suggest that the SP data obtained for the shadowed regions do not represent the lunar surface, which is composed of minerals, but represent levitating water. This observed result supports the sublimation of water on the lunar surface.
We analyzed SP data for shadowed regions with various latitude, local time and geological background. In this presentation, we will present the variation of water sublimation for each condition.
We analyzed near-infrared spectral data obtained by Spectral Profiler (SP) onboard SELENE, for shadowed regions over the lunar surface. The SP is a line-profiling spectrometer, which obtained the high wavelength resolution spectral data covering 500–2600 nm.
We re-calculated the reflectance for the shadowed regions, assuming that the incident light is not solar light but the light scattered on the surface of neighboring sun-lit regions. As results, we obtained spectrum features similar to water vapor for some of the shadowed regions, which might suggest that the SP data obtained for the shadowed regions do not represent the lunar surface, which is composed of minerals, but represent levitating water. This observed result supports the sublimation of water on the lunar surface.
We analyzed SP data for shadowed regions with various latitude, local time and geological background. In this presentation, we will present the variation of water sublimation for each condition.