Liquid water found on Saturn mooon
and World Science staff
Researchers say a spacecraft may have found evidence of liquid water reservoirs that erupt in geysers on Saturn’s moon Enceladus.
The moon would thus become one of just a handful of Solar System bodies known to have liquid water, and could reveal exciting new avenues for the search for life in the universe, the scientists said.
The researchers said the finding shows liquid water, and thus possibly life, may be more common in the universe than expected. It might even raise the possibility of life in Enceladus itself, some noted, although the tiny, volcanic moon would seem an inhospitable place.
Also, the occurrence of liquid water so near the surface is unusual, raising new questions about the mysterious moon, said the researchers. They used NASA’s Cassini craft to make the findings.
“Other moons in the solar system have liquid-water oceans covered by kilometers of icy crust,” said Andrew Ingersoll of the California Institute of Technology, Pasadena, Calif, a member of the research team. “What’s different here is that pockets of liquid water may be no more than tens of meters below the surface.”
“This is a radical conclusion—that we may have evidence for liquid water within a body so small and so cold,” added Carolyn Porco, leader of Cassini’s imaging team at the Space Science Institute in Boulder, Colo.
“However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms.”
Cassini images show icy jets and towering plumes shooting out particles, researchers said. Scientists examined several models to explain the process, and concluded that the jets might be erupting from near-surface pockets of liquid water above 0 degrees Celsius (32 degrees Fahrenheit), like cold versions of the Old Faithful geyser at Yellowstone National Park in Wyoming.
“We previously knew of at most three places where active volcanism exists: Jupiter’s moon Io, Earth, and possibly Neptune’s moon Triton,” said John Spencer, a Cassini scientist with the Southwest Research Institute in Boulder. “Cassini changed all that, making Enceladus the latest member of this very exclusive club, and one of the most exciting places in the solar system.”
“As Cassini approached Saturn, we discovered the Saturnian system is filled with oxygen atoms. At the time we had no idea where the oxygen was coming from,” said Candy Hansen, Cassini scientist at NASA’s Jet Propulsion Laboratory in Pasadena. “Now we know Enceladus is spewing out water molecules, which break down into oxygen and hydrogen.”
Scientists said they still have many questions. Why is Enceladus so active? Are other sites on Enceladus active? Might this activity have been continuous enough over the moon’s history for life to have had a chance to take hold in the moon’s interior?
In the spring of 2008, scientists say they’ll get another chance to look at Enceladus when Cassini, launched in 1997, flies within 350 kilometers (approximately 220 miles) of it.
“There’s no question, along with the moon Titan, Enceladus should be a very high priority for us. Saturn has given us two exciting worlds to explore,” said Jonathan Lunine, a Cassini team member at the University of Arizona in Tucson, Ariz. The mission scientists reported these and other Enceladus findings in this week’s issue of the research journal Science.
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