Planetary impact craters study through low-speed laboratory experiments

摘要

In this work, we study the ejecta velocity distribution of impacts at low speeds (10 m/s less than or similar to v(p)less than or similar to 70m/s). Our experiments comprise impacts with steel and glass projectiles launched from a vertical PVC air cannon, on two different quartz sand targets and recorded with a high-speed camera. The dynamics of the separate ejecta grains as well as the diameters and final shapes of the output craters are investigated through the scaling method developed by Housen et al. [4] based on the dimensionless pi-theorem. We also follow a similar method as Tsujido et al. [12], which allows us to derive scaling laws that connect impact events at different scales. We demonstrate that our results are consistent with experiments by previous works [1, 5, 12] carried out at much higher impact speeds (0.2 less than or similar to v(p)less than or similar to 1.5 km/s). Our experiments show that it is possible to draw valuable information for the study of planetary impact craters from laboratory low-speed impact experiments, such that, based on the parameters derived from this analysis, we estimate the theoretical diameters of four known impact craters (Wolfe Creek, Barringer, Lonar Lake and Chicxulub craters).