http://planetark.org/wen/53496(Picture) A handout image shows Enceladus from the Cassini spacecraft.Photo: NASA/JPL/Space Science Institute/Handout
Saturn's Moon May Hide Watery Caverns - And Life?
Date: 25-Jun-09
Country: UK
Author: Ben Hirschler
LONDON - Saturn's icy moon Enceladus could contain watery underground
caverns, forming a potential home for alien life, scientists said on
Wednesday.
German researchers have found salt -- a signature chemical for
seawater -- in ice grains from vapor jets streaming out of surface
cracks, providing the strongest evidence yet of a liquid water
reservoir beneath the moon's frozen crust.
A U.S. team said the amount of salt they had detected using a
different method suggested an earlier theory that water was boiling
explosively into the vacuum of space via geysers was wrong, and
evaporation was occurring quite slowly.
Both studies were published in the journal Nature.
One explanation for the slower evaporation may be that water is
emerging from pressurized chambers below the so-called tiger stripe
fractures in the moon's surface, said John Spencer of the Southwest
Research Institute in Boulder, Colorado.
"Our picture of its sub-surface must now be expanded to include the
possibility of misty ice caverns floored with pools and channels of
salty water, lurking beneath the tiger stripes," he wrote in a
commentary on the two scientific papers.
"What else may lurk in those salty pools, if they exist, remains to
be seen."
The Cassini spacecraft first discovered huge plumes erupting from
fissures near the south pole of Enceladus in 2005, sparking
speculation of a vast underground ocean spewing vapor through giant
Yellowstone-like geysers.
Since then, scientists have debated whether this meant that Enceladus
(pronounced en-SELL-ah-dus), with a diameter of only 310 miles, was
hiding a reservoir of liquid water. It is one of about 60 moons of
the ringed planet Saturn.
Frank Postberg of the Max Planck Institute for Nuclear Physics in
Heidelberg said the presence of sodium salts was compelling evidence,
indicating salty minerals were washed out from rock on Enceladus in
the same way oceans absorb salt on Earth.
He and colleagues reported they had found salty grains of ice after
analyzing data from Cassini's cosmic dust detector as it flew through
Saturn's outermost ring, where Enceladus orbits.
Whether or not Enceladus harbors life remains a mystery. But the
evidence of liquid water, coupled with heat near the moon's South
Pole, suggests it is possible.
"If you have this large amount of water in contact with a rocky core
and you have heat, then you have very good conditions," Postberg said
in a telephone interview.
"On top of that we measured a slightly alkaline pH value, which is
very good for the formation of complex organic molecules."
Scientists hope to find out more when Cassini makes two more close
fly-bys of Enceladus in November.
Date: 25-Jun-09
Country: UK
Author: Ben Hirschler
LONDON - Saturn's icy moon Enceladus could contain watery underground
caverns, forming a potential home for alien life, scientists said on
Wednesday.
German researchers have found salt -- a signature chemical for
seawater -- in ice grains from vapor jets streaming out of surface
cracks, providing the strongest evidence yet of a liquid water
reservoir beneath the moon's frozen crust.
A U.S. team said the amount of salt they had detected using a
different method suggested an earlier theory that water was boiling
explosively into the vacuum of space via geysers was wrong, and
evaporation was occurring quite slowly.
Both studies were published in the journal Nature.
One explanation for the slower evaporation may be that water is
emerging from pressurized chambers below the so-called tiger stripe
fractures in the moon's surface, said John Spencer of the Southwest
Research Institute in Boulder, Colorado.
"Our picture of its sub-surface must now be expanded to include the
possibility of misty ice caverns floored with pools and channels of
salty water, lurking beneath the tiger stripes," he wrote in a
commentary on the two scientific papers.
"What else may lurk in those salty pools, if they exist, remains to
be seen."
The Cassini spacecraft first discovered huge plumes erupting from
fissures near the south pole of Enceladus in 2005, sparking
speculation of a vast underground ocean spewing vapor through giant
Yellowstone-like geysers.
Since then, scientists have debated whether this meant that Enceladus
(pronounced en-SELL-ah-dus), with a diameter of only 310 miles, was
hiding a reservoir of liquid water. It is one of about 60 moons of
the ringed planet Saturn.
Frank Postberg of the Max Planck Institute for Nuclear Physics in
Heidelberg said the presence of sodium salts was compelling evidence,
indicating salty minerals were washed out from rock on Enceladus in
the same way oceans absorb salt on Earth.
He and colleagues reported they had found salty grains of ice after
analyzing data from Cassini's cosmic dust detector as it flew through
Saturn's outermost ring, where Enceladus orbits.
Whether or not Enceladus harbors life remains a mystery. But the
evidence of liquid water, coupled with heat near the moon's South
Pole, suggests it is possible.
"If you have this large amount of water in contact with a rocky core
and you have heat, then you have very good conditions," Postberg said
in a telephone interview.
"On top of that we measured a slightly alkaline pH value, which is
very good for the formation of complex organic molecules."
Scientists hope to find out more when Cassini makes two more close
fly-bys of Enceladus in November.
No comments:
Post a Comment
You only need to enter your comment once! Comments will appear once they have been moderated. This is so as to stop the would-be comedian who has been spamming the comments here with inane and often offensive remarks. You know who you are!