The moons orbiting Jupiter and Saturn appear to have subsurface oceans — tantalizing targets in the search for life beyond Earth. But it’s not clear why these seas exist at all. The post These Moons Are Dark and Frozen. So How Can They Have Oceans? first appeared on Quanta Magazine
For most of humankind’s existence, Earth was the only known ocean-draped world, seemingly unlike any other cosmic isle. But in 1979, NASA’s two Voyager spacecraft flew by Jupiter. Its moon Europa, a frozen realm, was decorated with grooves and fractures — hints that there might be something dynamic beneath its surface. “After Voyager, people suspected that Europa was weird and might have an ocean,”…