One Star Shines on Many Worlds: Exploring Extraterrestrial Water Through Observations of Scattered Light on the Moon and Mars

We investigate interactions between scattered light and water on the Moon and Mars. On the Moon, we develop an illumination and thermal model to examine small-scale temperatures and the thermal stability of volatile molecules at the Lunar Crater Observation and Sensing Satellite (LCROSS) impact site. We find that small-scale surface roughness creates a maximum temperature spread of approximately 10 K.

On Mars, we derive a scattering phase function for Aphelion Cloud Belt water-ice clouds (WICs) during Mars Years 34 – 36 using Mars Science Laboratory cloud movies. We compared our phase functions with seven previously-derived Martian WIC phase functions and two Martian dust phase functions, as well as modeled phase functions for seven different ice crystal geometries. We find poor to moderate agreement with our phase functions. We also investigate interannual and diurnal variability of our phase functions, finding that any variability is minimal, consistent with previous results.