Electromagnetic simulation and inversion of magnetic field data from planetary and asteroid analogs

Kurzfassung

The MagVector/MFX-2 experiment was conducted in 2018 as part of Alexander Gerst's horizons mission on the International Space Station (ISS). It was planned and directed by the German Aerospace Center DLR and Airbus Defense and Space. Its main objective was to learn about the interaction of celestial bodies with magnetic fields as they travel through space. For this reason, 13 different material and planetary rock samples orbited the Earth in a laboratory experimental setup onboard the ISS. The magnetic environment around the samples was continuously monitored by 33 sensors measuring the magnetic flux density in three components. The collected data material has been investigated using simulation and inversion software developed at the TU Freiberg. Here, we are going to report about the results of these virtual experiments that aim at reconstructing and understanding the observed magnetostatic and inductive responses generated by the samples. The known magnetic susceptibility of the samples was successfully recovered by a newly developed magnetostatic inversion algorithm after preprocessing the data to remove unphysical signal components. Furthermore, we have carried out a series of induction experiments using our Nedelec finite element unstructured tetrahedral mesh time-domain forward modeling code. Both codes allow for a highly accurate incorporation of the experimental geometry and the shape of the samples. The induction experiments showed that a significant inductive effect of the samples at the nearest sensor location cannot be expected below 1 to 10 kHz. Based on these findings, the method can be scaled up for the investigation of larger objects.