28 November 2008
Ice volcanos on a moon of Saturn
"Scientists continue to search for the cause of the geysers on Saturn's moon Enceladus. The geysers are visible as a large plume of water vapor and ice particles escaping the moon...
What generates Enceladus' jets is a burning question in planetary science, because if liquid water is involved, Enceladus would be shown to have everything it needs, in theory, to provide a habitable environment.
…the new Cassini observations, however, do support a mathematical model developed in 2007, which treats the vents as nozzles that channel water vapor from a warm, probably liquid source, to the surface at supersonic speeds... only high temperatures close to the melting point of water ice could account for the large number of ice particles present in steady state in Enceladus' jets.
A liquid water source inside Enceladus, they said, could be similar to Earth's Lake Vostok, beneath Antarctica, where liquid water exists beneath the ice. In Enceladus' case, the ice grains would then condense from the vapor escaping from the water source and stream through cracks in the ice crust to the surface and out into space.
... Enceladus is a prime target for Cassini to study in its extended Equinox Mission. The presence of liquid water inside Enceladus would have major implications for future astrobiological studies on the possibility of life within icy bodies of the outer solar system..."
(image credit to APOD)