Two dimensional particle-in-cell simulations of the lunar wake

Abstract

The solar wind plasma from the Sun interacts with the Moon, generating a wake structure behind it, since the Moon is to a good approximation an insulator, has no intrinsic magnetic field, and a very thin atmosphere. Following earlier one and one-half dimensional (112D) simulations, 212D simulations have been studied for the first time. 212D simulations in the solar wind rest frame with an initial circular void reveal structures similar to those found in the earlier simulations, indicating that the 112D simulations are a good approximation to the physics. The infilling of the wake was found to be anisotropic, with the infilling occurring predominantly parallel to the magnetic field. The 212D simulations that are stationary with respect to the Moon, allow the effect of solar wind magnetic fields oblique to the solar wind flow to be studied, and these reveal additional assymetries.