Modeling Thermal Emission under Lunar Surface Environmental Conditions

Abstract Thermal emission spectra can provide key insights into the composition and thermophysical properties of regolith on Moon other airless bodies. However, under lunar surface environmental conditions, uppermost millimeters (from which thermal originates) cannot be characterized by a single temperature, leading to changes in spectral characteristics that should accounted for interpreting measurements. Here, we develop apply Monte Carlo radiative transfer method model from particulate media with varying, nonisothermal subsurface temperature profiles. We three major mineral phases (pyroxene, olivine, plagioclase), investigate effects particle size packing density. Modeled are compared lab measurements acquired both ambient simulated conditions. find some cases, provides useful constraints magnitude profile established sample lunar-like whereas not well represented linear profiles considered this work. The is generally successful at predicting contrast but less accurately shifts position Christiansen feature emissivity maximum; illustrate discuss validity modeling approach range different cases. Model results also used quantify depth within observed originates; depends grain size, ranges ∼100 1000 μ m representative densities.