Figure 3 : Observed particle flux disturbance due to Ganymede. Left top panel illustrates the geometry during event #2, during which Juno’s equatorial crossing point crosses Ganymede’s; magnetic field lines (red) intersecting the Juno trajectory (dashed black) and magnetic equator (blue). The top right panel shows Juno’s trajectory in magnetic equatorial coordinates color coded with the intensity of radiation observed by the µASC. Bottom 3 panels show satellite and spacecraft equatorial crossing distance, S3 longitude, and µASC observations as a function of time (blue and red, averaged). Ganymede interaction events 1, 2, and 3 indicated.
µASC observations displayed in the bottom plot of figure 3 show clear signatures of Ganymede’s interaction with the charged particle environment. However, the signatures of the highly energetic particles that µASC is sensitive to (>20 MeV) are only observed when Ganymede and Juno have small phase separation.