Io-Accelerated Electrons and Ions

Earth-based measurements of the Io-modulation effect on Jovian decametric radio noise emission (Bigg, 1964) and the recently announced observation of intense Sodium-D optical emissions from the vicinity of Io (Brown, 1974) as well as various results from the Pioneer 10 Jupiter flyby (see Science,1974) indicate that the Jovian moon Io (and possibly Europa and Ganymede) play an active role in the Jovian magnetosphere.