Highlights from two years of remote sensing at Mars with MAVEN’s Imaging Ultraviolet Spectrograph

The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission’s Imaging Ultraviolet Spectrograph (IUVS) observes Mars in the far and mid ultraviolet (110-340 nm), investigating lower and upper atmospheric structure and indirectly probing neutral atmospheric escape. After two Earth years in orbit (one Mars year), IUVS has assembled a large quantity of data and made many discoveries, some of which we report here. Among the key results obtained by IUVS are: (1) discovery of the widespread occurrence of a diffuse proton aurora, representing a newly discovered means of energy deposition into the atmospheres of unmagnetized planets; (2) continued investigation of time-variability in H and O escape, which have dessicated the planet over its history; and (3) synoptic characterization of thermospheric variability and response to solar input. We will present an overview of these results and a discussion of their implications for the state of the atmosphere and its evolution.