3.2.9 Eruption plumes on Europa?
No visiting spacecraft has seen eruption plumes at Europa like those on Enceladus. However an exciting discovery was announced in December 2013. The Hubble Space Telescope, in orbit about the Earth, had found a faint ultraviolet glow caused by atoms of hydrogen and oxygen rising up to 200 km above Europa’s south pole in December 2012. This probably shows water molecules broken apart in the harsh space environment.
Europa’s plumes are not persistent. Evidence has been seen only when Europa is at its furthest from Jupiter, and repeat attempts at detection throughout 2014 were blank. If eruption plumes do indeed occur at Europa it is likely that they are less persistent than those currently occurring at Enceladus. Perhaps liquid water escapes violently when certain special cracks in Europa’s ice shell are open.