Simulating Meteor Ablation using Molecular Dynamics

Billions of small meteoroids enter the Earth's atmosphere each day, the majority smaller than a milligram. As these particles travel through the atmosphere, they collide with atmospheric molecules that impart energy to the meteoroid. The meteoroids heat up, and sputter off mass and thermally ablate. While there are theories about the heating mechanisms and mass loss of a meteoroid during atmospheric transit, little is known about the dynamics during the intense heating on a microscopic scale. We model the physics of atmospheric molecules impacting different meteoroid materials on the atomic scale via molecular dynamics simulations. The simulations calculate the dynamics of such processes in full 3D, allowing a range of parameters for the impacting molecule and meteoroid lattice energies. The sputtering yield's dependence on velocity was found to have a different shape than the standard theory predicts. We calculate the energy distribution of ablated particles, and the energy transfer coefficient is found to have a linear relationship when compared to velocity as opposed to the standard assumption of unity. These microscopic simulations will help improve macroscopic data analysis, theory, and simulations of meteors.