Space Weather Observations With InSight

Abstract

Solar activity, in the form of coronal mass ejections and corotating interaction regions, results in changes in the solar wind that propagate out through the solar system and interact with the magnetic field environments of planets. Such phenomena have been observed to affect the magnetic field and plasma around Mars as seen from orbit. However, no surface observations have previously been possible because of the absence of ground-based instrumentation. Here, for the first time, we observe the effects of increased solar activity with the magnetometer on the InSight mission in December 2020. We find several days of increased activity including magnetic field fluctuations at periods of minutes to hours. Although only the flanks of this relatively weak coronal mass ejection hit Mars, the observed effects provide insight into how solar activity alters magnetic fields at the surface.