Clues hidden in data from NASA’s Galileo spacecraft—which explored the Jupiter system between 1995 and 2003—suggest very strongly that the icy moon Europa is venting water into space, scientists report today in Nature Astronomy.

Long considered to be one of the most promising places to search for alien life in the solar system, Europa is known to have a global ocean containing vastly more water than all of Earth’s combined. Finding plumes raises the possibility that the ocean tucked beneath its icy shell might erupt into outer space, which means that tasting that alien sea and searching it for signs of life could be as simple as sending a spacecraft zooming through a plume of