Vortex-Dominated Aeolian Activity at InSight's Landing Site, Part 1: Multi-Instrument Observations, Analysis, and Implications

Abstract

Aeolian activity, the movement of dust and sand by the wind, is common on Earth and has been observed on other planets, including Mars. A new Mars lander, InSight, has for the first time monitored aeolian changes by combining imaging with weather, seismic and magnetic field measurements. Sand grains are seen moving along the ground and dust is lifted from both artificial and natural surfaces. We found these changes were rare, but almost always happened in the early afternoon when tornado-like phenomena, called convective vortices, passed by the lander, sometimes leaving dark surface trails behind. The combination of the background wind speed and the rotational wind speed within a vortex was likely to be high enough to detach particles from the surface and set them into motion. When these vortices passed by the lander, the seismometer detected the ground tilting, and there was a pulse in the magnetic field, indicating charged particles were part of these dust-clearing events.