4 ms·

We know that Enceladus and Europe have liquid water.

• mastazi 11y ago
  True, but to be fair the parent said "not long ago" and this is quite the case, it was only ten years ago that we first observed vapour plumes on Enceladus, and I think Europa's subsurface ocean hypothesis started to gain traction around the same time. We live in exciting times.
• fsloth 11y ago
  The proof for both is from this millenium (from Galileo and Cassini probes). To me it's still fairly recent. While I find the principle of induction does trivialize lot of mathematical calculations I cannot apply the same principle of non-wonderment to discoveries made in the material world.