Atmospheric erosion and replenishment induced by impacts upon the Earth and Mars during a heavy bombardment

► Monte Carlo simulation for atmospheric consequences of a (late) heavy bombardment. ► Probability distribution of impact velocities for Earth and Mars from Nice model (dynamical simulations). ► Scaling of models for impact erosion and impactor volatiles retention analyzed. ► Cases for Mars and the Earth. ► Atmospheric accumulation dominates erosion except for extremely volatilepoor asteroids.