[MHGinTN]

I think it means 'volcanic eruption'. A coronal ejection isn't the same thing is it?... On another note, could this eruption actually be due to an impact? It appears to be so massive, so out of proportion to Io's size.

[CarolAnn]

A coronal ejection is the energy released by our sun following an event like a solar flare. They are what causes Auroras here on Earth.

[RadioAstronomer]

I think it means 'volcanic eruption'

Yup, I knew what they meant, just that it was not clearly written and I was having a bit of fun :-).