Riso-chan, The first expedition to the bottom of the Marianas Trench was manned. Can't remember the name of the sub; Alvin or something. Joe, many scientists feel that Europa could have life beneath the ice crust. The constant tidal pull of Jupiter could cause the core of Europa to be molten and its sea floor to be at least slightly seismic so that the possibility of smokers and their oases and lifeforms, or some similar, could exist.
Mark
Mark