THE mystery of a volcano on Jupiter’s moon Io that appeared to have moved has
been solved.
In October, the Galileo spacecraft took pictures of a volcano named
Prometheus, which seemed to be 75 kilometres from where it was discovered by the
Voyager spacecraft 17 years ago.
“Volcanoes don’t do that on Earth,” says Rosaly Lopes-Gautier of NASA’s Jet
Propulsion Laboratory in Pasadena.
But at a meeting in Pasadena last week, Lopes-Gautier explained how Galileo’s
images show that the apparent motion of the volcano was caused when volcanic
debris flowed over a field of sulphur dioxide “snow” 75 kilometres away. “It
hits the reservoir of sulphur dioxide and creates a new plume,” she says.
Advertisement
