Numerical modelling of large asteroidal impacts on the earth

This paper deals with vertical impacts of asteroids 100-1000 kin in size at 10-20 km/s on the Earth and concerns both impact processes and computational questions. Numerical hydrodynamic simulations were carried Out using the Eulerian method SOVA with modifications made for spherical geometry and accurate conservation of potential energy. Two equations of state, Tillotson's an ANEOS, were used for the Earth iron core, mantle, and projectile. The gravitational forces dominate in the process of large impacts and the post-impact potential energy can reach a half of the impactor energy. A spectacular feature of these impacts is an uplift of dense target material to about a thousand kilometres above the Earth surface. The results of the simulations can be used as input parameters for models of early Earth evolution. (C) 2003 Elsevier Ltd. All rights reserved.