LASP Science Seminars
Peculiar Role of Io in the Magnetic Environment of Jupiter
Fran Bagenal (CU/LASP)
In the 60s and 70s ground-based observations – many made here in Boulder – indicated Io was peculiar: the innermost Galilean moon triggered radio emissions, appeared to brighten on emerging from eclipse, and optical emissions indicated clouds of sodium atoms and sulfur ions around Io. Further hints of Io’s peculiarity were indicated by the first spacecraft to visit Jupiter – the Pioneers in 1973-4. Such strange behavior became understandable when Voyager 1 and 2 flybys of Jupiter in 1979 revealed Io’s remarkable volcanism. When Voyager 1 passed close to Io, perturbations in the plasma and magnetic field showed Io generating magnetic waves propagating away from the moon, carrying million-Ampere electrical currents along the magnetic field towards Jupiter. Over the past 40 years the Io-Jupiter system has been explored with telescopes and spacecraft but a major breakthrough came this year when the Juno spacecraft flew directly through Io current system. This talk show how Io’s strange behavior has been revealed over the years and present the latest results from Juno.