Phase-specific nanoscale mechanics of anhydrous astromaterials and implications for larger-scale strength

The mechanical behavior of heterogeneous astromaterials is strongly influenced by their dominant mineral phases. Quantifying their mechanical properties is essential for modeling asteroid deflection, designing sample return systems, and planning in-situ resource utilization. Yet, data for the major mineral phases that comprise a large fraction of near-Earth objects (NEOs) remains scarce. Here, depth-sensing nanoindentation is used to measure nanoscale hardness (<i>H</i>), modulus (<i>M</i>), and ductility (<i>M</i>/<i>H</i>) for the primary phases in a representative stony meteorite. Targeted phases include anhydrous silicates, oxides, sulfides, and Fe-Ni metals. The Ashby plot of <i>M</i> versus <i>H</i> shows that metals and silicates are widely separated in property space. A rule-of-mixtures approach is applied to estimate upper bounds on bulk modulus, linking mineral-scale measurements to bulk mechanical behavior. These results provide new insights into the nanoscale mechanics of complex extraterrestrial materials and establish a foundation for connecting properties across scales.