HR: 16:30h
AN: SH54A-05 INVITED     [Abstracts]
TI: Comparative Planetary Aurora: Earth, Jupiter and Saturn
AU: * Clarke, J T
EM: jclarke@bu.edu
AF: Center for Space Physics Boston University, 725 Commonwealth Ave, Boston, MA 02215 United States
AB: Observations of Jupiter and Saturn's auroral emissions, their morphology, and time variations are now sufficiently advanced to begin some detailed comparisons with the Earth's aurora. Specifically, campaigns of Hubble Space Telescope (HST) UV imaging conducted as the Cassini spacecraft approached each planet have now been carried out, permitting direct comparisons with the local solar wind properties. While Jupiter has been much more thoroughly studied by HST than Saturn, the number of HST images of Saturn's aurora has multiplied by several times with the approach to and arrival of Cassini at Saturn. Where one used to think of the Earth's aurora as driven by the solar wind, Jupiter's aurora as driven by internal sources of plasma and rapid rotation, and Saturn as being intermediate between the two, it is now possible to determine directly how Saturn's aurora compare with the other planets. It has been found that Saturn's aurora exhibit characteristics reminiscent of both the Earth's and Jupiter's, and also show features that have not been observed at the other planets. The observations of Jupiter and Saturn will be reviewed, with a summary of current thinking on the interpretation of the various emission processes, what they tell us about each planet's magnetospheric processes, and how these relate to the Earth.
DE: 2704 Auroral phenomena (2407)
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 5719 Interactions with particles and fields
DE: 5737 Magnetospheres (2756)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly