Atmospheric entry of large meteoroids: implication to Titan

The preparation for the Cassini-Huygens mission gives an opportunity to revise the problem of an atmospheric entry and breakup of cratering meteoroids. The numerical modeling of the meteoroidʹs flight through the atmosphere is presented in comparison with more simple models. The simulation takes into account the brittle/ductile properties of the meteoroid material: the Grady-Kipp-Melosh model of tensile failure is accompanied with a simple model of the shear failure. The main difference with previously published models consists in the treating of the post-failure deformation of the damaged material as a flow of a cohesionless media with a dry friction. Numerical results are used to make a parameterization of a simple Grigorian-like model, which finally is applied to predict the atmospheric shielding effect on Titan. For a modern atmosphere of Titan and mostly ice projectiles the observable deficiency of impact craters due to atmospheric shielding would be in the range of 6–8 km, where the number of craters would be two times smaller than for the airless Titan.