Space Weathering‐Induced Mechanical Evolution of Lunar Minerals: Micromechanical Evidence From Chang'e‐5 Lunar Regolith Particles and the Laâyoune 002 Feldspathic Breccia Meteorite

Abstract

Deep‐space exploration requires reliable mechanical constraints for lunar materials; however, the scarcity of samples limits destructive macroscale testing. Here, we combine automated mineralogical analysis and nanoindentation to investigate the mineral‐scale mechanical behavior of two Chang'e‐5 regolith particles and a Laâyoune 002 feldspathic breccia comparison sample. Rather than treating these materials as bulk proxies for all mare and highland regolith regions, we compare analogous mineral domains using an identical testing protocol. Minerals in the Chang'e‐5 particles generally show lower elastic modulus and hardness, greater indentation depth and creep displacement, and higher plastic work ratios than analogous minerals measured in the interior polished section of Laâyoune 002. The strongest contrast occurs in ilmenite, where more plastic, energy‐dissipative deformation is observed. These measured contrasts document micromechanical differences among analogous minerals in the analyzed lunar samples. Their interpretation considers lithology, mineral chemistry, local microstructure, and impact history, with regolith processes and space‐weathering overprint as plausible contributors to the Chang'e‐5 response. First‐order homogenization of the analyzed particle‐scale assemblages yields equivalent elastic moduli of about 54 GPa for the Chang'e‐5 assemblage and about 78 GPa for the Laâyoune 002 assemblage. These results provide mineral‐resolved mechanical constraints for interpreting lunar material evolution and for designing better simulants, experiments, and multiscale engineering assessments.