Juno detects Jupiter’s highest-energy ions

Jupiter’s planetary radiation environment is the most intense in the solar system. NASA’s Juno spacecraft has been orbiting the planet closer than any previous mission since 2016, investigating its innermost radiation belts from a unique polar orbit. The spacecraft’s orbit has enabled the first complete latitudinal and longitudinal study of Jupiter’s radiation belts. Becker et al. leverage this capability to report the discovery of a new population of heavy, high-energy ions trapped at Jupiter’s midlatitudes.