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. Key Points: Juno passed near a magnetic reconnection X‐line in Ganymede's downstream region on 7 June 2021Juno Waves observations provide a positive indication of being in the reconnection separatrix siteJuno JADE electron measurements show the flux increase and pitch angle distributions expected in a separatrix region [ABSTRACT FROM AUTHOR]

Copyright of Journal of Geophysical Research. Space Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)