Proton aurora, a type of Martian aurora first identified in 2016, forms when protons from the solar wind interact with hydrogen in the extended portions of the Martian atmosphere and travel to lower regions. According to multi-year observations made using the Imaging UltraViolet Spectrograph (IUVS) onboard NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, this phenomenon is actually the most common form of aurora on Mars; it is observed...