NASA - National Aeronautics and Space Administration

Image above: Plumes of icy material extend above the southern polar region of Saturn’s moon Enceladus as imaged by the Cassini spacecraft in February 2005. The monochrome view is presented along with a color-coded version on the right. The latter reveals a fainter and much more extended plume component. Image Credit: NASA/JPL/Space Science Institute

There is a chance liquid water may exist on Saturn's moon, Enceladus – and even a possibility that life could be there, too – according to NASA scientists who are studying data from NASA's Cassini spacecraft.

High-resolution Cassini images show icy jets and towering plumes ejecting large quantities of particles at high speed as seen in images taken by the spacecraft. Scientists have found evidence the jets might be erupting from near-surface pockets of liquid water above 32 degrees Fahrenheit, like cold versions of the Old Faithful geyser in Yellowstone, according to NASA reports.

Scientists are eagerly anticipating the results from a closer Enceladus flyby proposed for an extended Cassini mission, according to Christopher McKay, a scientist at NASA's Ames Research Center, Moffett Field, Calif.

"The geysers seem like good evidence for liquid water," McKay observed. "The geysers and the methane in them both seem to up the chances for life. I would say that the chance for life is good enough to warrant further investigation."

Scientists believe the methane could come from three potential sources. Researchers say it could be primordial – very ancient – or it could be manufactured deep within Enceladus, and lastly, and least likely, the methane could be biological in origin.

McKay and Carolyn Porco, Space Science Institute, Boulder, Colo., will preside over numerous scientific presentations during a morning session, "Enceladus: Possibilities for Water and Life," beginning at 8 a.m. PST, Monday, Dec. 10, 2007, at the Moscone Convention Center South in San Francisco.

Though Saturn's moons are far from the sun, there could be liquid water on Enceladus because the "general thought is that there must be some sort of tidal heating," according to McKay.

Some scientists hypothesize that bacteria, living off hydrogen and carbon dioxide, and making methane, might live on Enceladus. The bacteria would be "similar to subsurface, methanogen ecosystems found on Earth," McKay explained. "Water rock reactions produce the hydrogen from basalt," McKay said, after citing two types of chemical reactions.

According to McKay, if the methane is going to be recycled back to hydrogen, then there needs to be a region in Enceladus with temperatures about 500 degrees Celsius (932 degrees Fahrenheit) or more.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, Calif., manages the mission for NASA's Science Mission Directorate. The Cassini orbiter was designed, developed and assembled at JPL.

John Bluck
NASA Ames Research Center, Moffett Field, Calif.
Phone: 650-604-5026
Email: jbluck@mail.arc.nasa.gov