杏吧原创

THE mystery of a volcano on Jupiter鈥檚 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.

鈥淰olcanoes don鈥檛 do that on Earth,鈥� says Rosaly Lopes-Gautier of NASA鈥檚 Jet
Propulsion Laboratory in Pasadena.

But at a meeting in Pasadena last week, Lopes-Gautier explained how Galileo鈥檚
images show that the apparent motion of the volcano was caused when volcanic
debris flowed over a field of sulphur dioxide 鈥渟now鈥� 75 kilometres away. 鈥淚t
hits the reservoir of sulphur dioxide and creates a new plume,鈥� she says.