Modeling Lunar Surface Charging Under Space Weather Conditions Derived From the ARTEMIS and OMNI Data

This article models lunar surface potential when the Moon is in the solar wind and in different regions of the magnetosphere under both quiet and moderate space weather conditions. The analysis is based on fully kinetic particle-in-cell (PIC) simulations of regolith surface charging and plasma environments derived from NASA’s acceleration, reconnection, turbulence, and electrodynamics of the Moon’s interaction with the Sun (ARTEMIS) measurements and NASA/GSFC OMNI data. For the global plasma environmental conditions considered, the most severe charging occurs when the Moon is in the plasma sheet during a magnetic substorm, with a lunar surface potential ranging from more than −400 V at the equator to more than −750 V at the terminator with respect to the ambient. The results presented provide a benchmark for charging risk prediction for future lunar surface exploration activities.