The Juno Synchrotron Emission Investigation

Juno's close polar orbit is ideal for studying Jupiter's polar magnetosphere. Although Juno's orbit is designed to avoid Jupiter's intense radiation belts, Juno carries a suite of microwave radiometers that are capable of remotely sensing the synchrotron emission originating from the relativistic electrons trapped close to Jupiter. The microwave radiometry investigation (MWR) is primarily focused on investigating the dynamics and composition of Jupiter's deep atmosphere, however, the experiment will in fact provide a detailed investigation of Jupiter's synchrotron emission. The MWR suite is comprised of six radiometers operating at a range of wavelengths between one and fifty centimeters. As with the radio telescope observations from the Earth, the radiometers are sensitive to the relativistic electrons emitting synchrotron emission as they gyrate in Jupiter's strong magnetic field. The proximity of the spacecraft to Jupiter allows for a clear separation of atmospheric and synchrotron emission, something not possible using Earth based radio telescopes. During the 6 hours centered on perijove, the MWR instrumnet will collect complete observations of Jupiter's synchrotron emission from a variety of vantage points including above the poles looking down, and from within the radiation belts looking out. Because the synchrotron emission is a directional phenomena dependent on both the orientation of the magnetic field and the pitch angle of the emitting electron, Juno will provide an unprecedented investigation into the energy, L-shell, and pitch angle distribution of the high energy electrons making up Jupiter's radiation belts.