Europa is the smallest of Jupiter's four major (Galilean) moons. As best we can tell it is covered by a thick icy surface that shields a large liquid saline salt water ocean from Jupiter's lethal radiation. Plumes of water that escape the icy surface would indicate subsurface geological activity, and thus a source of heat for Europa's ocean. Why does this matter? It means that, based on what we know about Europa, and about microscopic life's ability to thrive in similar environments here on Earth, Jupiter's moon could theoretically harbor life. And, if it did, it would, ironically, be another step like the ones that got Galileo in hot water (and house arrest) with the ruling religious authorities of his day. It would be one more small step for mankind toward the realization that the universe does not revolve around human beings. In the story of civilization thus far, we have written ourselves into the lead roles, the main characters. We are why everything else i