3D Particle Characteristics of Highland Lunar Soil (No. 60501) Obtained by Micro X-Ray CT

A lunar surface soil sample from Descartes highland (No. 60501) is investigated by micro X-ray CT. Based on the obtained 3D information on particle shape and enclosed voids and cracks together with the information from microscopic images, we classified the particles into four groups: (1) monomineralic particles mostly corresponding to plagioclase, (2) micro breccias composed of a lot of mineral fragments, (3) agglutinate particles with relatively smooth surface and enclosed voids and (4) spherical glass beads. The detailed shape indices such as elongation ratio, flatness ratio and sphericity are computed for representative particles by image processing. Furthermore, in order to evaluate the mechanical properties of lunar soil from the particle information, image-based DEM is applied to directly model the particles, and simple shear simulations with such modeled particles are demonstrated. The computed shear resistance is in good agreement with the best estimate of Apollo model. Coupling such numerical tool with the above-mentioned particle statistics, we can evaluate the mechanical properties of various lunar soil from their petropraphic information.