Exploration of Giant Planet Magnetospheres. Fran Bagenal, University of Colorado. Jupiter Top Priority Polar Regions Multi-Spacecraft. Giant Planet Magnetospheres. Giant! Rotation Dominated Satellite plasma sources J&S Symmetric ~Dipolar Strong plasma production
Fran Bagenal, University of Colorado
Global Electric fields
Dust & Rings
Why not Uranus & Neptune?
Why Focus on Jupiter?Again? Still?
What can be done from Earth?
Radio Astronomy - synchrotron & auroral emissions
Visible - Io, plasma torus (limited)
IR - Io volcanoes, Auroral emissions
HST - aurora, Io, torus
EUVE, FUSE, CHANDRA….
System variable and coupled - need to observe multiple components simultaneously
Limited access to telescopes
Need in situ measurements
SMall EXplorer mission under study - Earth-orbiting UV telescope to observe Io, the torus and Jovian aurora
Coverage, coverage, coverage… Space & Time
Ground, Rocket, LEO Studies
Simplest missions - “Ulysses-style”
Priorities for missions
- what accelerates the precipitating energetic particles?
- why does ‘wake’ emission extend half way around Jupiter
Orbit: Polar elliptical orbit (1.1 Rj x ~20 Rj, >80 degrees inclination). The apojove distance is less critical, to be optimized between 20-40 Rj (with longer period orbits lengthening the mission time vs. requiring less mess). The evolution of the orbit will help cover much of magnetosphere. Orbit optimized to get maximum polar coverage with minimum radiation dosage.
Spacecraft: Solar powered, chemical propulsion for orbit insertion and corrections, large onboard memory (for accumulating data over the poles/perijove for downloading over apojove).
Challenges: propulsion, power, communication, radiation - as with all Jupiter missions
The ultimate test of magnetospheric science comes from applying what we have learned at Earth to other planets