Do these water jets come from an underground ocean orbiting Saturn? If so, it could nurture the only extraterrestrial life-forms in our solar system. But one scientist says that water is too pure to come from a buried ocean on Enceladus, one of Saturn's moons.

The water has none of the sodium which it would have after years of contact with rock, claims University of Colorado scientist Nick Schneider. But other scientists argue there might be sodium which Schneider's telescope analysis failed to detect. And even Schneider isn't claiming there's no ocean on Enceladus, just that the water jets don't come from it. NASA may have to mount a mission to find out for sure if the Saturn moon holds life forms. Image by NASA/JPL [BBC]