E scusate se è poco…
March 9, 2006 Erica Hupp/Dwayne Brown Headquarters, Washington (202) 358-1237/1726
Jet Propulsion Laboratory, Pasadena, Calif.
NASA’S CASSINI DISCOVERS POTENTIAL LIQUID WATER ON ENCELADUS
NASA’s Cassini spacecraft may have found evidence of liquid water
reservoirs that erupt in Yellowstone-like geysers on Saturn’s moon
Enceladus. The rare occurrence of liquid water so near the surface
raises many new questions about the mysterious moon.
“We realize that this is a radical conclusion - that we may have
evidence for liquid water within a body so small and so cold,” said
Carolyn Porco, Cassini imaging team leader at the Space Science
Institute, 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
High-resolution Cassini images show icy jets and towering plumes
ejecting large quantities of particles at high speed. Scientists
examined several models to explain the process. They ruled out the
idea the particles are produced or blown off the moon’s surface by
vapor created when warm water ice converts to a gas. Instead,
scientists have found evidence for a much more exciting possibility.
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 in Yellowstone.
“We previously knew of at most three places where active volcanism
exists: Jupiter’s moon Io, Earth, and possibly Neptune’s moon Triton.
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,” said John Spencer, Cassini scientist, Southwest Research
“Other moons in the solar system have liquid-water oceans covered by
kilometers of icy crust,” said Andrew Ingersoll, imaging team member
and atmospheric scientist at the California Institute of Technology,
Pasadena, Calif. “What’s different here is that pockets of liquid
water may be no more than tens of meters below the surface.”
“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 (JPL) in Pasadena. “Now we know Enceladus is
spewing out water molecules, which break down into oxygen and
Scientists 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 will get another chance to look at
Enceladus when Cassini flies within 350 kilometers (approximately 220
miles), but much work remains after the spacecraft’s four-year prime
mission is over.
“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, Cassini interdisciplinary scientist,
University of Arizona, Tucson, Ariz.
Mission scientists report these and other Enceladus findings in this
week’s issue of Science. The Cassini-Huygens mission is a cooperative
project of NASA, the European Space Agency and the Italian Space
JPL, a division of the California Institute of Technology, manages the
Cassini-Huygens mission for NASA’s Science Mission Directorate. The
Cassini orbiter was designed, developed and assembled at JPL.
For Cassini images and information about the research on the Web,
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