MAVEN Observations of Magnetic Reconnection at Martian Induced Magnetopause

The Martian-induced magnetopause (IMP), characterized by the sudden changes of magnetic fields and ion compositions, is the transition boundary separating the magnetosheath from Martian induced magnetosphere. Based on the magnetic field and plasma measurements by Mars Atmosphere and Volatile EvolutioN, we for the first time report a magnetic reconnection at the dayside IMP. The clear plasma jet and bipolar Hall magnetic field provide solid evidence for the identification of the magnetic reconnection. Our observations demonstrate that the newly arrived interplanetary magnetic field and the anchored magnetic field in the induced magnetosphere can reconnect with each other at the IMP. Such reconnection allows the planetary ions to escape from Mars through the reconnected magnetic fields across the IMP, resulting in a significant increase in the local loss rate of the ionospheric ions.