Simulating Interactions with Lunar Rocks

The moon, like all air-less bodies, is exposed to the harshness of the environment of space. The surface is bombarded by solar wind ions, cosmic rays, Ultraviolet, and X-ray radiation, which interact with the soil in a process referred to as space weathering. Further studies have found that micrometeorite impacts affect the moon’s soil, and by studying micrometeorite interactions, we can learn about the early conditions and processes in the solar system's history. Knowing about the dynamics of the moon’s regolith leads to a better understanding of the complex mineralogy on the moon. The purpose of this research is to simulate the lunar regolith and explore the dynamics of interacting particles. One of the main constituents of lunar rocks is the mineral forsterite (Mg2SiO4). We apply the public-domain software package Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) to simulate a lunar rock and its interactions at its surface. A crystal slab of forsterite is created with the packages Vesta and Moltemplate. Classical trajectory calculations are performed with LAMMPS to relax the slab into an amorphous state. LAMMPS is then used to simulate particle collisions with the forsterite slab. Ultimately, we plan to study both solar wind proton and micrometeorite collisions, which are proposed as mechanisms for the production of water in the lunar regolith. The tool VMD is used to visualize the time-dependent interactions.