Low-temperature thermal and physical properties of lunar meteorites

Abstract

Lunar meteorites are the most diverse and readily available specimens for the direct laboratory study of lunar surface materials. In addition to informing us about the composition and heterogeneity of lunar material, measurements of their thermo-physical properties provide data necessary to inform the models of the thermal evolution of the lunar surface and provide data on fundamental physical properties of the surface material for the design of exploration and resource extraction hardware. Low-temperature data are particularly important for the exploration of low-temperature environments of the lunar poles and permanently shadowed regions. We report low-temperature-specific heat capacity, thermal conductivity, and linear thermal expansion for six lunar meteorites: Northwest Africa [NWA] 5000, NWA 6950, NWA 8687, NWA 10678, NWA 11421, and NWA 11474, over the range 5 ≤ T ≤ 300 K. From these, we calculate thermal inertia and thermal diffusivity as functions of temperature. Additionally, heat capacities were measured for 15 other lunar meteorites, from which we calculate their Debye temperature and effective molar mass.