Figure 1 : Motion of a 20 (green), 60 (blue) and 100 MeV (red) electron injected with an equatorial pitch angle of 10° at 15 RJ (Ganymede’s orbital distance), bouncing between mirror points and slowly drifting westward around Jupiter with a drift period of 29, 87, and 144s respectively, and half bounce drift of ~2° along the magnetic equator.