Europa is squeezed and stretched by gravitational forces from Jupiter and the other Galilean satellites. Tidal friction heats the interior of Europa possibly enough to maintain the solar system's biggest ocean. The only way to know is to go there and check. Image courtesy Woods Hole Oceanographic Institution. Astrobiologists are increasingly convinced that life on Earth itself might have started in the sulfurous cauldron around hydrothermal vents.
Vent environments minimize oxygen and radiation, which can damage primitive molecules.
Indeed, many of the primordial molecules needed to jump-start life could have formed in the subsurface from the interaction of rock and circulating hot water driven by hydrothermal systems. The images in this story are courtesy of Dive and Discover . Image courtesy of shipboard scientists from College of William and Mary, Harvard University, Monterey Bay Aquarium Research Institute, University of New Hampshire, Oregon State University, Portland State University, University of Washington, Woods Hole Oceanographic Institution. Changes in Europa's magnetic field, detected during last week's flyby, point to a salty, subterranean ocean. Europa are a telltale sign of salty liquid water beneath the moon's icy crust.