Based on data from scientific computer models, Io formed in a region around Jupiter where water ice was plentiful. Io's heat, combined with the possibility that there was water on Io shortly after it was formed, could have made life possible, although Jupiter's radiation would have removed the water from the surface.

Can life live on Io?

Io is generally considered a poor candidate for life because of all the radiation Jupiter blasts it with. In addition, no organic molecules have been detected on its surface, and it has only an extremely thin atmosphere devoid of detectable water vapor.

Could Europa have life?

So far, there is no evidence that life exists on Europa, but Europa has emerged as one of the most likely locations in the Solar System for potential habitability. Life could exist in its under-ice ocean, perhaps in an environment similar to Earth's deep-ocean hydrothermal vents.