Towards a better understanding of the environments of Jupiter’s moons Europa and Ganymede

In Webseminar by admin

Wednesday 25 November 2020 11AM
Christina Plainaki, PhD Agenzia Spaziale Italiana

In lack of an adequate number of in situ observations, our knowledge on the radiation-induced processes in the exospheres of Jupiter’s icy moons as well as on the exchange of material between the icy surfaces and the Jovian magnetosphere remains limited. The existence of a wide variety of approaches in modeling, based on different scenarios and considerations, has resulted in a still fragmentary understanding of the interactions of the magnetospheric ion population with the icy surfaces of Europa and Ganymede and their exospheres. Models often show discrepancies in the source and loss rates of the different exospheric constituents and their spatial and temporal distribution, also in the context of planetary space weather. This is of particular relevance for the study of Ganymede, the only known moon in the Solar System to possess an intrinsic magnetic field embedded within a planetary magnetosphere. Indeed, the dynamics of the entry and circulation inside Ganymede’s magnetosphere of the Jovian energetic ions, as well as the morphology of their precipitation on the moon’s surface determine the variability of the sputtered-water release and exosphere generation. The exospheres of Europa and Ganymede link Jupiter’s plasma sheet and energetic ion population to the satellites’ icy surfaces. The so-called planetary space weather conditions around these moons, therefore, can also have a long-term impact on the weathering history of the icy surfaces.

In this talk, I will review some key points in modelling the interactions of the Jovian magnetospheric ions with the environments of Ganymede and Europa and discuss the related exosphere generation processes. Some recent modeling results will be also presented and discussed in the context of future missions to the Jupiter system (e.g., ESA/JUICE) and optimization of future observation strategies for studying the icy moon environments.