Does Magnetic Reconnection Occur in the Near Lunar Surface Environment?

Abstract

The near lunar surface contains small-scale magnetic field structures that provide a natural test bed for observing plasmas with a non-zero Hall electric field, as well as potentially facilitating electron-only reconnection. This study presents observational evidence of magnetized electrons as well as demagnetized ions when THEMIS-ARTEMIS probe B reached an altitude of ∼15 km above the lunar surface. Additionally, observations suggest the presence of a field line topology change and traversal of a closed magnetic field structure containing solar wind electrons, suggestive of magnetic reconnection having occurred at some point between the solar wind interplanetary magnetic field and a lunar crustal magnetic field. Thus, the observations presented here are consistent with previous studies that predict prominent Hall electric fields near lunar crustal magnetic fields and further suggest that the solar wind interplanetary magnetic field may reconnect with lunar crustal magnetic fields, most likely via electron-only reconnection.