A Magnetic Perspective on Giant Planet Interiors

Abstract:  Magnetic fields are windows into planetary interiors. Key questions concerning giant planet interiors include the level of differential rotation, the existence and extent of stable stratification, and the size and nature of the central core. I will describe the latest magnetic field observations from the Cassini and Juno missions, and how they provide a new perspective on answering these key questions when combined with magnetohydrodynamic theory and numerical modeling. Implications for giant planets outside the solar system will be discussed. I will then highlight upcoming planetary magnetic field observation opportunities (e.g. Psyche mission to asteroid 16 Psyche, Europa Clipper, BepiColombo to Mercury, JUICE to Ganymede and the Jupiter system) and how they will help answer questions ranging from the thermal evolution history of asteroid 16 Psyche to the salinity of Europa’s ocean. I will conclude by discussing how future in-situ magnetic field measurements at Uranus and Neptune will offer a key missing piece in our understanding of planetary magnetism and interiors.