Presentation #404.01 in the session “NEO Surface Properties”.
Many asteroids are predicted to be cohesive aggregates (i.e., a loose collection of grains held together by cohesion and self-gravity). Qualitative observations, of Itokawa for example, show natural grain distributions by size, with the larger grains tending toward the surface and the distal ends of asteroids. The Strata-1 experiment on the ISS aimed to test the viability of naturally occurring vibrations as a mode of granular segregation in microgravity. Strata-1 consisted of tubes of grains, some glass and some simulant, exposed to the natural vibrations on the ISS. Upon return to Earth, analysis of the tube of spherical grains using x-ray computerized tomography (XCT) images suggested that granular segregation occurred. In this work, we numerically model the Strata-1 experiment and compare the resulting segregation to that observed in the physical experiment. Comparing the physical experiment with a numerical model allows us to test the accuracy of our model as well as the sensitivity of the results to the initial packing of the grains.