Asymmetric magnetic anomalies over young impact craters on Mercury

Mercury's crustal magnetic field map includes anomalies that are related to impact craters. Mercury's surface has a low iron abundance, but it is likely that some impactors brought magnetic carriers able to register the planet's magnetic field that was present during impact. Anomalies associated with the relatively young Rustaveli and Stieglitz craters are asymmetric with respect to the crater center. We analyze the location of the magnetic anomalies and the impact crater morphologies to understand whether there is any correlation. We investigate the geological framework of these two craters to constrain the overall impact dynamics. In both cases, magnetic anomalies correlate well with the location of impact melt and the inferred impact direction. Both impact angles were probably 40–45°, with preferential distribution of the melt downrange. Inversion dipoles suggest that the impact melt located downrange encompasses some magnetized material, which is hence likely responsible for the detected magnetic anomalies.