Compositional diversity of the Europa-Ganymede plasma environment

Jupiter’s plasma sheet is understood to be dominated by Io-genic material, mostly in various charge states of sulfur and oxygen. This material moves radially away from Jupiter, filling its magnetosphere. The material in the plasma sheet interacts with Europa and Ganymede, which are also sources of magnetospheric pickup ions, mostly in the form of both atomic and molecular hydrogen and oxygen. Juno’s plasma instrument JADE, the Jovian Auroral Distributions Experiment, has provided the first comprehensive in-situ observations of the composition of Jupiter’s plasma sheet with its Time-of-Flight mass-spectrometry capabilities. Here, we present observations of the magnetospheric composition in the Europa-Ganymede region of Jupiter’s magnetosphere. We highlight how Europa-genic material is often present and at times can be the dominant population for certain atomic masses, revealing a more complex and compositionally diverse magnetosphere than previously thought.