Diverse Electron and Ion Acceleration Characteristics Observed Over Jupiter's Main Aurora

Two new Juno-observed particle features of Jupiter's main aurora demonstrate substantial diversity of processes generating Jupiter's mysterious auroral emissions. It was previously speculated that sometimes-observed potential-driven aurora (up to 400 kV) can turn into broadband stochastic acceleration (dominating at Jupiter) by means of instability. Here direct evidence for such a process is revealed with a mono-energetic electron inverted-V rising in energy to 200 keV, transforming into a region of broadband acceleration with downward energy fluxes tripling to 3,000 mW/m(2), and then transforming back into a mono-energetic structure ramping down from 200 keV. But a second feature of interest observed nearby is unlikely to have operated in the same way. Here a downward accelerated proton inverted-V, with inferred potentials to 300-400kV, occurred simultaneously with downward accelerated broadband electrons with downward energy fluxes as high as any observed (similar to 3,000 mW/m(2)). This latter feature has no known precedent with Earth auroral observations.