Early-stage Ejecta Velocity Distribution

Introduction: The ejection velocity distribution of an impact event determines the emplacement of material on planetary bodies. Dimensional analysis[1] predicts a single power law relationship between ejection velocity and time (or ejection position) for main-stage excavation. At very early times, however, when energy and momentum are still being coupled to the target, “[t]he power-law expressions for ejecta velocities may not hold.” [1]. This study investigates high speed early-time departures from the accepted power-law relationship over a range of projectile diameters.