µASC observations of Jovian energetic electrons interaction with Europa moon

<p>Since Juno&#8217;s orbit insertion, the attitude reference for the MAG investigation onboard Juno, the micro Advanced Stellar Compass (&#181;ASC), and as a part of its additional functionality, continuously measures high energy electron fluxes in Jupiter&#8217;s magnetosphere. The &#181;ASC camera head unit (CHU) sensitivity to electrons with kinetic energy greater than 15 MeV and protons with energies >80MeV, provides a means of in-situ mapping of electron fluxes sampled during 47 Juno orbits.</p> <p>The focus of this study are events observed when Juno is traversing M-shell of the Galilean moon, Europa, which shows distinctly different signature from that the other moons.</p> <p>We present &#181;ASC observations of energetic electrons interaction with Europa moon. Europa generates a wake, that affect the high energy electron driftshell, by scattering electrons into the loss-cone. The wake is then dissolved and these interactions are observed around 20&#176; down tail. On the upstream side, the energetic drift shell is free from hard radiation as Europa acts as an obstacle for the energetic electrons. This assymetry result in a lower electon density on the upstream side resulting in an E-field filling in the e^- population from surrounding driftshells in less than 10&#176;.</p>