AbstractWe present a comprehensive synthesis of plasma and magnetic field observations during Juno's flyby through Europa's wake on 29 September 2022, which has a closest approach distance of 353 km. Compared to Galileo, Juno includes measurements of plasma electrons and mass‐per‐charge resolved ions. This allows for characterization of the thermal electron environment near Europa and definitive identification of the ion species present in that region. The plasma and magnetic field properties bounding Europa's wake are similar to conditions at Europa's orbit from Voyager and Galileo. While the ion flow patterns within the wake and accelerated flows along Europa's flank are consistent with the Galileo E4 wake flyby, the ion flows slowed more, reaching a low of 65 km s−1 near the wake center, and the ion densities near closest approach are ∼4 times higher (∼170–190 cm−3) as Juno's flyby occurred closer to Europa. The H+ and H2+ densities peaked near closest approach while heavy ion densities peaked near the wake center. These measurements quantify the modification of Jupiter's plasma disk composition by fresh injection of pickup ions. Properties of 0.032–32 keV electrons such as temperature, thermal pressure, and beta are reported for the first time in Europa's wake, the electron temperature reaching a low of ∼35 eV in the wake center, compared to 70–80 eV in Jupiter's nearby plasma disk. The components of the magnetic field are variable throughout the wake, the magnetic pressure being at least a factor 40 larger than the electron thermal pressure.
