Direct Observations of Magnetic Reconnections at the Magnetopause of the Martian Mini-Magnetosphere

Abstract

While Mars lacks a global intrinsic magnetic field, it does exhibit crustal magnetic anomalies (mostly in its Southern Hemisphere). These crustal magnetic anomalies directly interact with solar wind, which forms a mini-magnetosphere and a region denoted the mini-magnetopause. Using magnetic field and plasma measurements from the Mars Atmosphere and Volatile Evolution, we report a novel case of magnetic reconnection at the Martian mini-magnetopause. In this process, protons and oxygen ions from the Martian atmosphere were accelerated during reconnection and likely escaped along the outflow direction. Magnetic reconnection may occur between the interplanetary magnetic field and crustal magnetic fields at the Martian mini-magnetopause, which contributes to planetary ion escape, solar wind entering the mini-magnetosphere and the evolution of magnetic topology in the dayside Martian mini-magnetosphere.