Observations of lunar mini-magnetospheres

The study of the near-Moon plasma environment is one of the key scientific objectives of China’s Chang’E-1 and Chang’E-2 missions. We investigate here specifically the interactions of the Lunar Magnetic Anomalies (LMA) with the Solar Wind (SW),based on the proton/ion data acquired by the Solar Wind Ion Detector (SWID) mounted on both lunar orbiters.Through the measured proton phase space distribution, we propose tentatively that the lunar magnetic anomalies could shield and heat the incident solar wind particles,with the possible formation of mini-magnetospheres near the anomaly.This study serves as one of the very few observational incidences of the presence of these plasma structures.This work, as well as follow-up studies, may contribute to the studies of both lunar space weathering and magnetospheric physics on scales where finite gyroradius effects are important.