What concrete evidence has Galileo found of the suspected ocean below Europas frozen surface?
We do not have “concrete” evidence for an ocean presently existing below Europa’s ice crust. However, the Galileo data have considerably strengthened the case for this. First, the images show clear evidence for near-surface melting and movements of large blocks of icy crust in ways that are similar to icebergs or ice rafts on the Earth. Second, there are very few impact craters on the surface, suggesting that this activity took place recently, geologically speaking. The problem is that we have no precise way to measure the exact age of the surface, and it is possible that we are looking at an ancient “frozen” ocean, not a current one. We feel the evidence favors an ocean now but that it is not conclusive.
