Observational Characteristics of Electron Distributions in the Martian Induced Magnetotail

Abstract

Mars's magnetotail represents a unique case within the solar system, embodying both intrinsic and induced magnetic fields. Yet, the electron dynamics within this region have remained largely unexplored. Utilizing nine years of electron and magnetic field data from the Mars Atmosphere and Volatile EvolutioN mission (MAVEN), we conducted a comprehensive statistical analysis to uncover the average electron characteristics in the Martian induced magnetotail for the first time. Our findings revealed a distinct pattern of electron behavior: in the lobe regions, electrons tend to converge toward the current sheet, driven by an ambipolar electric field that is directed from the current sheet toward the lobe. Additionally, we observed that electrons are more energetic in the +E hemisphere, where the solar wind electric field points away from Mars, compared to the opposite hemisphere. This mirrors the behavior of planetary ions and supports the hypothesized formation mechanism of sinuous auroras.