Abstract
Surface layers on small bodies, such as comets, asteroids, and planetesimals, are considered to be granular materials in which silicate and/or ice particles are sintered. Cavity formation processes and ejected material (ejecta) properties due to impacts on such sintered granular layers are important to understand the evolution of the surface layers on the small bodies and of the dust particles. In this study, we carried out numerical simulations of impacts on sintered granular targets by Distinct Element Method, (DEM), which calculates motion of each particle. We prepare a target that consists of 384,000 equal-sized (radius of 1mm) particles randomly placed in a rectangular container. To simulate the sintered granular target, we introduce a simple adhesion and rolling resistance model into our target particles. A projectile particle (radius of 3mm) is impacted vertically onto the target at 300 m/s, with various intensities of adhesion and the degree of rolling resistance between target particles. Based on our numerical simulations, we discuss the cavity formation and the ejecta size and velocity distribution on the sintered granular target.
