Evidence of Magnetic Reconnection in Ganymede's Wake Region From Juno

Magnetic reconnection has been commonly reported between the solar wind IMF and the magnetic field of Earth and other planets. A similar phenomenon is expected between Jupiter's magnetosphere and Ganymede's mini magnetosphere inside the Jovian magnetosphere. This article is the first report of a reconnection event in the tail region of Ganymede. We present compelling evidence that Juno flew in close proximity to an X-line, that was not within the tail current sheet, but rather in the turbulent wake area of Ganymede. We report the observation of distinctive electron Bernstein mode waves with unique characteristics particular to a separatrix region of the reconnection site. We detect a clear reversal of a magnetic field component. Electron densities and pitch angle distributions also indicate that Juno possibly traversed the inflow, and outflow region surrounding the separatrix region. Finally, from the time sequence of the observations by the different instruments on Juno, we reconstruct a likely trajectory of Juno around the reconnection site.