LRO LAMP Observations of Diurnally-Varying Hydration

Data from the Lunar Reconnaissance Orbiter (LRO) Lyman Alpha Mapping Project (LAMP) and Diviner are used to investigate dayside hydration on the Moon. LAMP is a far-UV spectrograph that utilizes the diagnostic spectral characteristics of water to search for hydration both in polar regions and at lower latitudes throughout the lunar day. An initial study of a highlands and a mare region found that far-UV spectral signatures are consistent with surface water on the Moon varying in abundance with both terrain type and local time/temperature. A thermal desorption model reproduces the observations. Here we expand our analysis to larger regions of the lunar surface to investigate larger-scale trends in diurnally-varying hydration and understand variations in hydration with surface composition and temperature/latitude. Such observations are relevant to characterizing the global lunar water cycle and ultimately understanding water as a potential resource for future robotic and crewed missions to the lunar surface.