A Combined Experimental And Numerical Approach To Understanding Impacts Involving Regolith On Planetary Surfaces

Planetary surface disturbances due to micrometeoroids or exploration activities can result in impacts between objects that occur at a range of velocities, including many events at very low velocities (\u3c5 m/s). Continuous bombardment by micrometeoroids pulverizes the surfaces of airless bodies, breaking apart the rocky surfaces and generating the ubiquitous dusty regolith on these objects. While these impacts are typically high-velocity, lower-energy secondary impacts from cratering events redistributes regolith on the surfaces. Exploration activities on an asteroid or the Moon represent an additional low-energy impact process that can disturb the regolith in novel ways. To understand the response of regolith-covered surfaces to these impact processes, we must understand the granular mechanics in a range of conditions, as well as characterize the different mechanical properties of the regolith grains. Such knowledge is crucial in the design of exploration hardware and operations, in the mitigation of asteroid hazards, and in the design of space mission tests for asteroid deflection. Here, we present work that addresses these questions through a combination of experimental studies and numerical simulations that build from exploration of basic acrylic spheres to more complex compositions and particle shapes