Saturn Moon May Have Water

Feb. 6, 2008 -- Astrophysicists in Germany say they can add evidence to bolster theories that water, one of the precious ingredients for life, exists on the Saturnian moon Enceladus.

A tiny satellite measuring just 504 kilometers (315 miles) across, Enceladus has become one of the most fiercely debated objects in the solar system, thanks to close-up pictures taken by the NASA Cassini probe.

Enceladus has a brilliant white shell of ice that is untouched except for some strange-looking grooves and impacts from space rocks.

Cassini revealed plumes of water vapor that gush from surface stripes near its south pole, shooting crystal jets upwards for hundreds of miles into space.

Fuelling discussion about the origin of these strange "cryo-volcanoes" is the fact that icy particles of dust are also mixed in with the eruptions, but beguilingly travel far slower than the vapor.

A team led by Juergen Schmidt of the University of Potsdam, near Berlin, say they can now answer at least this part of the mystery.

Their theory is that water vapor and ice grains are blasted through funnels in the so-called tiger stripes -- and the grains, being heavier, rub against the rough sides of these holes.

The friction slows the particles down, which explains why they travel at a far lower velocity in the void.

For this to happen, though, liquid water would have to exist in equilibrium with ice and vapor beneath the moon's frigid crust, according to the model.