- WASHINGTON (Reuters) -- Parts
of Mars were once "drenched with water," so much that life could
easily have existed there, NASA said on Tuesday.
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- The robot explorer Opportunity has seen clear evidence
of the main goal of Mars exploration -- that water once flowed or pooled
on the Red Planet's surface.
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- "Opportunity has landed in an area of Mars where
liquid water once drenched the surface," NASA associate administrator
Ed Weiler told a news conference. "Moreover, this area would have
been good habitable environment."
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- That does not mean that evidence of life has been found
-- but it suggests that life could have evolved on Mars just as it did
on Earth, NASA said.
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- It does mean NASA can go ahead with a plan to eventually
send people to Mars.
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- Opportunity landed on Jan. 24 in a small crater on the
vast flat Meridiani Planum near the planet's equator. It has spent most
of its time there studying finely layered bedrock in the crater's wall.
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- Scientists have been puzzling over whether the layers
were formed by wind, volcanic lava flows or water, and if little round
balls nicknamed "blueberries" may have been formed by water.
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- "BLUEBERRIES," HEMATITE AND LAVA FLOWS
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- They have also been intrigued by the discovery of a gray
shiny mineral called hematite, which on Earth is formed in water.
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- The space agency said they had determined that the hematite,
the blueberries and the heavy salt content of the area all adds up to one
conclusion -- salt water.
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- "We have concluded the rocks here were once soaked
with liquid water," said Dr. Steve Squyres of Cornell University in
Ithaca, New York, who leads the scientific investigation.
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- "It changed their texture, and it changed their
chemistry," he added. "We cannot yet tell you with certainty
that these rocks were laid down in a lake, in a pool, in a sea."
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- They may have been formed by percolating groundwater,
he said.
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- "(This area) would have been suitable for life,"
Squyres said. "That doesn't mean life was there. But this was a habitable
place on Mars at one period of time."
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- More will be known when a mission can be sent to bring
back some Mars rocks, Squyres said. "The best way to get at the age
is going to be to bring some of this stuff back," he said.
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- "It is clear that we are going to have to do a sample
return," agreed Weiler. He said work will start right away on preparing
for an eventual human mission to Mars.
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- In the meantime, another robotic mission will be set
up, probably to pick up some rocks and soil and bring them back to the
Earth for close analysis.
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- Pictures from the rover's panoramic camera and microscopic
imager show a rock it has been looking at called "El Capitan"
is pocked with indentations about a centimeter (0.4 inch) long.
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- "This distinctive texture is familiar to geologists
as the sites where crystals of salt minerals form within rocks that sit
in briny water," NASA said in a statement.
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- The composition and density of the salts are comparable
to the saltiness seen in the Dead Sea, which straddles the border between
Israel and Jordan, NASA said.
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- Opportunity may soon be sent to a nearby crater about
30 meters (100 feet) deep to see if deeper layers can be examined, said
Joy Crisp, project scientist at NASA's Jet Propulsion Laboratory in Pasadena,
California.
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- NASA also held out hope that Spirit, Opportunity's twin
rover examining another area of Mars, might find something interesting.
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