March 10, 2006 in Nation/World

Saturn moon may have liquid water

John Johnson Jr. Los Angeles Times
 

Images from NASA’s Cassini spacecraft show that Saturn’s moon Enceladus may have liquid water erupting from giant Yellowstone-like geysers, raising the tantalizing possibility that the icy moon could support some form of life, scientists said Thursday.

“We realize that this is a radical conclusion,” said Carolyn Porco, a researcher at the Space Science Institute in Boulder, Colo., and head of the Cassini imaging team. “If we’re right, we think we are looking at another environment in the solar system where we have liquid water and the potential for living organisms.”

The images, taken over the last year, show dramatic eruptions from the southern polar region from volcanoes spitting water and ice particles up to 260 miles in space, according to a report on the findings published today in the journal Science.

Showing just how powerful the subsurface forces are, the plumes are almost as big as the moon itself, according to the scientists.

While scientists have found evidence for liquid water on other objects in the solar system, Porco said that the confluence of water, heat from volcanic activity and previously detected organic compounds make Enceladus a prime candidate for NASA’s search for life.

“This has the potential to redirect space exploration,” Porco said.

Scientists cautioned that there is no way to know how much water is near the surface of the small moon or how long it has been there. There is no way to tell if its environment is hospitable to life.

“I don’t think we know enough yet,” said David Morrison, a senior scientist at NASA’s Astrobiology Institute at the Ames Research Center in Mountain View, Calif.

But Porco said the presence of all three prime indicators for life now makes Enceladus a “better bet” than many other places in the solar system.

The Cassini spacecraft, managed by the Jet Propulsion Laboratory in Pasadena, Calif., has been observing Saturn and its 47 known moons since June 2004.

Until now, most of the major discoveries on the $3.3 billion mission involved Saturn’s large moon, Titan, which is shrouded in an intriguing smog-like atmosphere of methane, ethane, acetylene and other hydrocarbons.

Enceladus, discovered in 1789 by British astronomer William Herschel, has long been a curiosity because of its variety of terrains, from craters as large as 20 miles across, to fissures, plains and other deformations. These features proved that the tiny moon – about 310 miles in diameter – had been geologically active fairly recently.

Scientists had clues that something unusual was happening around Saturn even before it reached the icy moon. When Cassini approached the ringed planet, it discovered the Saturnian system is filled with oxygen atoms.

“Now we known Enceladus is spewing out water molecules, which break down into oxygen and hydrogen,” said Candy Hansen, a Cassini scientist at JPL.


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