Half a Mars Year of Atmospheric Results from InSight (Invited)

Kurzfassung

The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission landed in Elysium Planitia at ~4.5N, 136E on November 26th 2018 in local winter (Ls~295deg). Since then, nearly half a Mars year ago, InSight has continuously monitored the evolution of surface pressure, air temperature, wind speed and direction, and magnetic fields with the Auxiliary Payload Sensor Suite (APSS), as well as surface temperature with the Heat-Flow and Physical Properties Package (HP3) radiometer. InSights cameras have also monitored seasonal and diurnal changes in atmospheric opacity and clouds, as well as aeolian activity including grain motion and the formation of dust devil tracks. In addition, the seismometers of the Seismic Experiment for Interior Structure (SEIS) have captured the seismic response to Martian weather for the first time. We will present an overview of InSights discoveries over its first half year on Mars, highlighting new perspectives enabled by the high-frequency, continuous nature of its meteorological measurements and its diverse set of instruments. Surface pressure reveals the local impact of the annual, global-scale CO2 cycle, the seasonally-varying dust cycle and baroclinic wave activity, and the large-scale, daily thermal tides, as well as the response to shorter timescale, more locally generated phenomena such as gravity waves and convective vortices. InSights wind measurements are crucial to understand important processes such as dust storm onset and aeolian reshaping of the surface; they also provide a vital constraint on the validation of numerical models that encapsulate our understanding of the circulation and enable it to be extended to other locations and conditions. Comparing the timing of sediment removal with high winds, rapid pressure drops, and/or related seismic signals allows aeolian activity to be associated with wind shear stress and/or vortex passage. We will describe key observations over the first half year and their significance, from the signal of high latitude baroclinic waves in pressure and wind at InSights near-equatorial location, to the water cycle as evidenced by images of water-ice clouds, to the seasonal variation of winds in comparison with predictions by different models, to the environmental response to regional dust storms.