Survey of Saturn’s magnetopause and bow shock positions over the entire Cassini mission: boundary statistical properties, and exploration of associated upstream conditions

Abstract:

The Cassini spacecraft orbited the planet Saturn from July 2004 – September 2017, and its varied orbital trajectory took it across the magnetopause and bow shock boundaries multiple times, at varying radial distances, local times, latitudes, and phases of the solar cycle. Here we present a comprehensive list of these boundary crossings, derived primarily using data from the Cassini magnetometer instrument, with cross-validation against the electron spectrometer data where available.

In this presentation, we examine the variability in boundary location and use the crossing times in concert with models of the bow shock and magnetopause to infer the upstream solar wind dynamic pressure at the times of crossings. This analysis allows us to understand the limitations of the Cassini trajectory for studying boundary physics under a range of solar wind driving conditions. In addition, rapid traversals of the magnetosheath are used to estimate the range of speeds of boundary motion.

We also outline several future avenues for exploitation of this comprehensive list of boundary crossings.