Comparative Planetary Aurora: Jupiter, Saturn, and the Earth

Detailed observations of the UV aurora from Jupiter and Saturn have been carried out with the cameras on the Hubble Space Telescope. These images reveal distinct similarities, and also differences, between the giant planet auroras and auroral processes on the Earth. In general, the Earth's aurora are controlled by the interaction of the Earth's magnetic field with the solar wind, Jupiter's aurora are dominated by internal dynamics and plasmas, and Saturn presents an intermediate case with features of each of the other planets. We are learning much more about the outer planets through comparisons with the in situ measurements now being made by the Galileo and Cassini spacecraft. The Hubble images will be presented for comparison with each other, and with other results on the Earth, in this short overview of the subject. This research has been supported by grant GO-8657.01-99A from the Space Telescope Science Institute to the University of Michigan. >http://www.sprl.umich.edu/CassiniHSTJupiterflyby/</a>