Features and Trends Identified in Observations at Mars and Comets

Abstract

<p>Mars has surface crustal fields but no intrinsic magnetic field. A dense ionosphere exists at Mars where the solar wind interaction can drive an induced magnetic field to develop. The atmosphere of Mars often extends far into the solar wind. Newly-ionized particles then mass load the solar wind. Comets instead have no intrinsic or surface magnetic field and the ionosphere is generally not thick enough to develop a significant induced magnetic field around the comet. However, it has a highly variable atmosphere reaching far out in to the solar wind suggesting the solar wind interaction should be similar in some respects to that at Mars. This presentation postulates some similarities in the details of the solar wind interaction with these two objects, and the consequences in the ionosphere of extended mass loading of the solar wind under varying driving conditions. The motivation for these ideas are from recent observations made by the NASA MAVEN and the ESA ROSETTA missions, both of which show periodic trains of large amplitude features in the magnetic field and corresponding kinetic plasma structures.</p>