A new view on the solar wind interaction with the Moon

TL;DR

Recent lunar missions have uncovered complex interactions between the solar wind and the Moon, revealing phenomena like ENA backscattering, surface sputtering, mini-magnetospheres, and diverse plasma populations, challenging previous passive models.

Contribution

This paper reviews recent findings and presents a new perspective on the solar wind-Moon interaction based on recent observational data.

Findings

Detection of energetic neutral atoms from lunar surface

Observation of mini-magnetospheres around magnetic anomalies

Identification of diverse plasma populations around the Moon

Abstract

Characterised by a surface bound exosphere and localised crustal magnetic fields, the Moon was considered as a passive object when solar wind interacts with it. However, the neutral particle and plasma measurements around the Moon by recent dedicated lunar missions, such as Chandrayaan-1, Kaguya, Chang'E-1, LRO, and ARTEMIS, as well as IBEX have revealed a variety of phenomena around the Moon which results from the interaction with solar wind, such as backscattering of solar wind protons as energetic neutral atoms (ENA) from lunar surface, sputtering of atoms from the lunar surface, formation of a "mini-magnetosphere" around lunar magnetic anomaly regions, as well as several plasma populations around the Moon, including solar wind protons scattered from the lunar surface, from the magnetic anomalies, pick-up ions, protons in lunar wake and more. This paper provides a review of these recent findings and presents the interaction of solar wind with the Moon in a new perspective.