And yet, defiantly, these alien seas remain liquid. A Mirror-Wrapped Ocean Scientists suspect that a handful of moons orbiting Jupiter and Saturn—and maybe even some spinning around Uranus and Neptune—harbor oceans. Hefty Ganymede and crater-scarred Callisto produce weak, Europa-like magnetic signals. Saturn’s haze-covered Titan, too, very probably has a liquid-water subsurface ocean. These “are the […]