[Geysers] Geysers of Enceladus

[Jacob Young]

I'm expecting a GOSA trip in the future....

Link:
http://www.nasa.gov/mission_pages/cassini/media/cassini-20060309.html

NASA's Cassini Discovers Potential Liquid Water on
Enceladus

 03.09.06 

 
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. 

 Image right: 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. 
+ Full caption 

"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 Dr. Carolyn Porco, Cassini
imaging team leader at 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 large quantities of particles
at high speed. Scientists examined several models to
explain the process. They ruled out the idea that the
particles are produced by 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. 

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

"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 Dr. John Spencer, Cassini
scientist, Southwest Research Institute, Boulder,
Colo. 

"Other moons in the solar system have liquid-water
oceans covered by kilometers of icy crust," said Dr.
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." 

Other unexplained oddities now make sense. "As Cassini
approached Saturn, we discovered that the Saturnian
system is filled with oxygen atoms. At the time we had
no idea where the oxygen was coming from," said Dr.
Candy Hansen, Cassini scientist at NASA's Jet
Propulsion Laboratory in Pasadena. "Now we know that
Enceladus is spewing out water molecules, which break
down into oxygen and hydrogen." 

Scientists are also seeing variability at Enceladus.
"Even when Cassini is not flying close to Enceladus,
we can detect that the plume's activity has been
changing through its varying effects on the soup of
electrically-charged particles that flow past the
moon," said Dr. Geraint H. Jones, Cassini scientist,
magnetospheric imaging instrument, Max Planck
Institute for Solar System Research,
Katlenburg-Lindau, Germany. 

Scientists still have many questions. Why is Enceladus
currently 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? 

"Our search for liquid water has taken a new turn. The
type of evidence for liquid water on Enceladus is very
different from what we've seen at Jupiter's moon
Europa. On Europa the evidence from surface geological
features points to an internal ocean. On Enceladus the
evidence is direct observation of water vapor venting
from sources close to the surface," said Dr. Peter
Thomas, Cassini imaging scientist, Cornell University,
Ithaca, N.Y. 

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 Cassini's four-year prime mission
is over. 

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

The Cassini-Huygens mission is a cooperative project
of NASA, the European Space Agency and the Italian
Space Agency. JPL, a division of the Caltech, manages
the mission for NASA's Science Mission Directorate.
The Cassini orbiter was designed, developed and
assembled at JPL. 

For images and more information, visit:
http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov . 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com