Beneath its icy shell, Jupiter’s largest moon harbors a massive, salty ocean of water — one of the key ingredients for the emergence of life as we know it — based on the latest evidence from the Hubble Space Telescope.
“A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth,” John Grunsfeld, associate administrator for NASA’s Science Mission Directorate, said in a news release.
Using data from the telescope, researchers said they found evidence for the existence of Ganymede's hidden sea by measuring the motions of auroras caused by the moon’s magnetic field. The ocean sits beneath a 95-mile-thick sheet of ice and could have a depth of 60 miles, the scientists said.
It’s not the first time someone has raised the possibility that Ganymede's ice might conceal a deep ocean. Earlier studies have suggested the moon might have alternating layers of ice and water that one NASA researcher compared to "a Dagwood sandwich." Two other of Jupiter’s moons, Europa and Callisto, are also thought to have water beneath their ice-frosted crusts.
--- Matthew DeLuca