Dust devils' signature around the InSight landing site (Mars): analysis of HiRISE satellite images and SEIS seismic data

The NASA InSight mission to Mars successfully landed on November 26^th, 2018 in Elysium Planitia. One of its goal is to characterize the seismic activity of Mars, which can be triggered by three main types of sources: tectonic, meteoritic, and atmospheric (e.g. turbulence). In this study we use high resolution satellite images (HiRISE) that have been acquired before the landing of InSight (May and July 2014) and analyze a preliminary set of images acquired after the landing (e.g., December 6^th and 11^th, 2018; February 4^th and 21^st, 2019). We show a large activity of dust devil tracks going across a wide zone around the landing site (~100 km²). Tracks are characterized by dark linear traces ranging from a few meters to more than ten meters wide and oriented in the ambient wind direction that can be directly compared to wind direction recorded by the InSight lander's meteorological package. Several tracks with cycloidal features ranging from 50 to 140 m of diameter are also observed. Detailed analyses are performed in order to determine the distribution of azimuths, sizes, and distances from the lander, of each dust devil passage identified on the HiRISE images. We also analyze the signature of the observed dust devils in the seismometer (SEIS) data. Moreover, forthcoming HiRISE observations will be used to further characterize ongoing dust devil activity and improve the statistics of those events.