Planetary life on Mars/Europa; particularly after reading the full Odyssey 2001/2010/2061 series (or whatever the years are), it's something that's always fascinated me - those deep deep oceans on Europa in particular. Europa, btw, is a decent sized moon of Jupiter. So decently sized, in fact, that it's almost Earth-sized (which is a mere 6400Km radius at the equator).
Has life ever developed there - whether the most basic singular cell (or whatever equivalent) form, or even sea creatures the likes of which might remind us of early Earth life? I'm very interested to see what, if anything, the probes we've sent out return when they get there. Is it feasible to dig down through the ice (it may meters thick, several Km thick, or several hundred/thousand Km thick - we don't really know for sure).
Someone please tell me when we know.