Radical! Liquid Water on Enceladus

The following appears in the current release of Astrowire. The article is
sourced as a press release from NASA:


March 9, 2006: 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 this 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 organisms."

High-resolution Cassini images show icy jets and towering plumes ejecting
huge 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 Institute, Boulder.

"Other moons in the solar system [may] 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 hydrogen."

Scientists still have many questions. Why is Enceladus so 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 the geysers--and
another crack at answering these questions--when Cassini flies within 350
kilometers (approximately 220 miles) of Enceladus.

"There's no question, along with the moon Titan, Enceladus should be a very
high priority for us," said Jonathan Lunine, Cassini interdisciplinary
scientist, University of Arizona, Tucson, Ariz. "Saturn has given us two
exciting worlds to explore."

Mission scientists report these and other Enceladus findings in this week's
issue of Science.


--
Martin R. Howell
"The Astro Post"
www.theastropost.com