Impact erosion of planetary atmospheres: For estimations of the total amount of the atmospheric loss

Abstract

Impact event vaporizes an impactor and target and produces a vapor cloud. The vapor cloud can accelerate the planetary atmosphere and cause the loss of atmosphere. It is called 'impact erosion'. We investigated the impact erosion in an ideal adiabatic atmosphere by computational means. The strong shock propagates vertically as predicted by Newman et al. (1999). On the other hand, horizontal flow blows the atmosphere away from the impact point. This flow pattern is not reported by any previous studies. We will discuss the parameter dependence of the amount of the atmospheric loss.