Observations and Modeling of Martian Auroras

Observations of planetary auroras form a new area of planetary exploration from space, especially for nonmagnetic planets since various kinds of auroras like Discrete, Proton and Diffuse auroras have been observed at Mars. We review the latest results of Martian auroras obtained by the instruments (1) SPICAM (Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars) aboard Mars Express (MEX) and (2) IUVS (the Imaging Ultraviolet Spectrograph) on MAVEN (the Mars Atmosphere and Volatile Evolution mission). The MARSIS instrument (the Mars Advanced Radar for the Subsurface and Ionosphere Sounding) on MEX, in addition, exhibited strong ionizations in some electron density profiles, thus providing further evidence for the existence of Martian auroras. We review these MARSIS observations as well. In addition, we review various models of Martian auroras.