Effect of the Interaction of Jovian Magnetosphere with Europa’s Exosphere on Pick-up Ion Population and Plasma Environment

Abstract:

With hypothesized liquid water ocean beneath its crust and observed large amount of oxygen in its exosphere, Europa is one of the potentially habitable locations of Solar system. This made the satellite the object of high scientific interest, the primary goal of Clipper mission drafted by NASA in particular. As of today, certain amount of data is already available (e.g. from Galileo spacecraft), yet more is awaited from Juno spacecraft, which is on its way to Jupiter.

Europa’s exosphere should be studied with connection with Jovian magnetosphere, as the two form together a complex system. They are tightly coupled through the processes of the magnetospheric ion sputtering, photolytic and electron reactions. Successful investigation of coupled system requires a simultaneous simulation of both its components.

Previous approaches studied this system in a piece-wise manner. Our efforts presented here are aimed at developing of a more global approach that would combine the exosphere and magnetosphere into a single model. This approach is more complete as it accounts for mutual influence of Jovian magnetosphere and Europa’s exosphere and allows us to study their time dependent interaction. We employed coupled MHD (Block-Adaptive Tree Solarwind Roe-type Upwind Scheme) and Monte-Carlo (Adaptive Mesh Particle Simulator) codes. Among the properties studied are distributions of pick-up ions (spatial, energy, pitch angle) and mass-loading of the magnetosphere in the vicinity of the satellite. A brief comparison of these properties with those resulted from previous works on the problem (Lipatov et al., 2010; Ip et al., 1998) and analysis of how introduced interaction of the satellite’s atmosphere with Jovian magnitosphere changes the results are provided.