Space Weather Event of 10 September 2017: Observations at Mars

The deep Solar Cycle (SC) 23 minimum and the modestly active SC 24 maximum have produced generally weaker solar events and heliospheric conditions. However on 10 September 2017 during the minimum phase of SC 24, active region 12673 (AR2673) produced some strong solar activity, including an X8.2 class flare and a fast (~3,300 km/s) and wide coronal mass ejection (CME). Although AR2673 was not centrally facing Mars (~67°E from the Sun-Mars line), the solar events impacted the local space environment at Mars. This includes upper atmospheric heating by emissions from the X8.2 flare, high fluxes of solar energetic particles (SEPs) impacting the atmosphere and reaching the surface, bright emissions of a diffuse (global) aurora, and observation of a Forbush-like decrease due to the encounter of Mars with the ICME. We will discuss some of these results in detail and present an overview of the observations obtained at Mars from various missions, including Mars Atmosphere and Volatile Evolution (MAVEN), Mars Express (MEX) and Mars Science Laboratory (MSL). We will also present the event observations at Earth/L1 and STA along with heliospheric simulation results from Wang-Sheeley-Arge (WSA)-Enlil-cone together with the SEPMOD SEP event modeling to provide a more global context of the event period.