Penetration of supernova ejecta in the solar system

In this paper, we investigate the mechanism by which supernova ejecta can penetrate the solar system, and in particular, directly deposit live radioactivities on Earth. A purely hydrodynamic interaction between a supernova blast and the solar wind yields a limit of 10 pc as the maximum supernova explosion distance in order for supernova plasma to penetrate within 1AU. However, there exists evidence that the vast majority of heavy elements in a supernova remnant may be depleted onto grains, hence they can be considered as charged particles which do not participate in the plasma dynamics of the interaction of the supernova plasma and the solar wind. We examine the motion of these charged particles as they decouple from the supernova plasma and are influenced by the solar magnetic, radiation and gravitational field. We find that given the large incoming velocities of the charged grains, they suffer little or no deflection within the solar system. Consequently, the dust penetration to 1 AU has essentially 100% transmission probability, and the dust capture onto the earth should have a geometric cross section.