Juno Observations Connected to the Io Footprint Tail Aurora

The Juno spacecraft crossed flux tubes connected to the Io footprint tail at low Jovian altitudes on multiple occasions. The transits covered longitudinal separations of approximately 10 ̊ to 120 ̊ along the footprint tail. Juno’s suite of magnetospheric instruments allow for detailed measurements of a variety of physical parameters for the Io footprint tail. Juno observed planetward electron energy fluxes of ~70 mW/m2 near the Io footprint, and ~10 mW/m2 farther down the tail, along with correlated, intense electric and magnetic wave signatures which also decreased down the tail. All observed electron distributions were broad in energy, possibly suggesting an Alfvénic acceleration process, and did not show any inverted-V structure that would be indicative of acceleration by a quasi-static, discrete, parallel potential. Here, we discuss the JADE, UVS, Waves, and Magnetic field measurements taken during Juno’s transits through the Io footprint tail flux tubes during perijoves 5-7 and compare these measurements with existing theoretical models describing the tail formation.