Hypervelocity impact experiments on solid CO2 targets

The results of impact experiments on solid CO2 are presented, The resulting crater morphology has been measured (crater depth, diameter and volume). The data are for normal incidence impacts, at typically 5 km s(-1), of solid steel spheres of diameters 0.4 to 2.0 mm onto solid CO2. The size range of the projectiles permits a determination of the dependence of the crater parameters with impact energy. The craters are shallow, with material removed mainly by spallation (crater depth/diameter approximate to 0.2), Compared to similar impacts in water ice, the craters in CO2 are smaller (by a factor of 2.2 in diameter and 8.9 in volume). The size distribution of the ejecta is measured and is found to vary strongly with the angle of ejection.