Preliminary analysis of the data obtained has provided important information about the emission from Io's atmosphere and its interaction with Jovian magnetosphere:
Strong Ly-alpha
emission has been discovered near Io's poles. The newly
discovered Ly-alpha emission is not detected above Io limb. S I or O I
emission shows bright spots roughly aligned with the magnetic
equipotential line through Io. S I and O I
emissions are not enhanced in the polar regions where strong
Ly-alpha emission is observed. S I and O I
emissions extend well above the limb of Io, and extends diffusely
around the entire limb of Io with an enhancement on the side
towards the plasma torus. S I and O I
intensities show a similar temporal variation, increasing by a
factor of two on timescales of an hour. The temporal
variations of FUV S I and O I emissions are strongly correlated
with simultaneous ground-based observations of [O I] 6300Å emission
intensity. The Ly-alpha
emission shows no detectable time variation. S I and O I
emissions are detected to about 10" beyond Io, but exhibits
no time variability similar to that of the equatorial bright
spots is detected.