The origin of chondrites: Metal-silicate separation experiments under microgravity conditions - II

In order to understand mechanical processes likely to be occurring on the surfaces of asteroids, we have performed experiments with mineral mixtures on NASA's KC‐135 microgravity facility. The behavior of sand and iron filing mixtures, the sand and metal being in the proportions and with grain sizes of ordinary chondrite meteorites, was observed with digital cameras as gas was flowed upward through the mixtures and the plane went through cycles of positive, zero, negative and normal gravity. Partial separation of gas and sand occurred readily under gas flow and microgravity conditions and sometimes survived subsequent turbulence. This behavior is consistent with predictions of the Ergun equation derived from terrestrial experiments. The data have implications for understanding chondrite genesis, for understanding the spectra of asteroid surfaces, and for the design of equipment to function on asteroid surfaces.