Io: The Prometheus Plume
Two sulfurous eruptions are visible on
Jupiter's volcanic moon Io in
this color composite Galileo image.
On the left, over Io's limb, a new bluish plume rises about 86 miles
above the surface of
a volcanic caldera known as Pillan Patera.
In the middle of the image, near the night/day shadow line, the
ring shaped Prometheus plume is seen rising 45 miles
above Io while
casting a shadow to the right of the
volcanic vent.
Named for
the Greek god who gave mortals fire,
the
Prometheus plume is visible in every
image ever made of the region dating back to
the Voyager flybys
of 1979 - presenting the possibility that
this plume has been continuously active for at least 18 years.
This image was
recorded on June 28 at a
distance of 372,000 miles.