Juno Diagnosis of Magnetospheric Dynamics at Jupiter with Energetic Neutral Atoms

Energetic Neutral Atom (ENA) cameras on orbiting spacecraft at Earth and Saturn have helped greatly to diagnose these complex magnetospheres. Within this decade, the European Space Agency’s Jupiter Icy Moons Explorer (JUICE) mission will arrive at Jupiter and make ENA imaging a major thrust in helping to understand its complex magnetosphere. The present polar-orbiting Juno mission carries no ENA camera, but the energetic particle JEDI instrument is serendipitously sensitive to ENA’s with energies > 50 keV, provided there are no charged particles in the environment to mask their presence. Juno offers great service to the interpretation of both past and future ENA imaging with its orbit allowing unique viewing perspectives. Here we report on several components of ENA emissions that can probe the dynamical state of the regions involved, including the space environment of the orbit of Io, that of Europa, and Jupiter itself. A special focus here will be new observations of ENA emissions from Jupiter’s polar regions, the proper interpretation of which may end up being unique to the Juno mission, even after the JUICE mission.