Links:
"NASA says Mars once drenched in water," Geotimes Web Extra, March 2, 2004
For more Geotimes coverage of Mars, click here.
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Scientists from NASA’s Mars Exploration Rover mission projects announced
March 2 that they had found definitive evidence for “a lot of water”
at some point in the planet’s history. Principal investigator Steve Squyres
of Cornell University said water could have “drenched” the surface,
possibly creating a habitable landscape for some time.
“Ever since Opportunity touched down,” Squyres said in a press conference
at NASA headquarters in Washington, D.C., “we have been puzzling over it.”
The layered rocks in the crater where the rover Opportunity landed in January
hold “tantalizing clues,” he said, to answer the question: “Were
these altered by liquid water? The answer to that is definitely yes.”
Squyres emphasized that the researchers do not know how long or when the water
may have been present, or if the water was at the surface or existed as groundwater.
Nevertheless, he said, the team found four criteria at the outcrop that pin
down evidence for liquid water present in large quantities.
The strongest of those pieces of evidence is weathered-out forms in the sediment
that look like sulfur hydrate crystals, shaped approximately as gypsum is on
Earth. “For sulfide hydrates,” Squyres said, “you have got to
have water.”
The team stressed that their results come from a very small section of Mars.
“We’re talking about 20 centimeters” of outcrop thickness, Squyres
said. John Grotzinger, geologist for the Mars rover team, said that seeing other
sites will be important, including a future trip to a part of the outcrop that
seems to have crossbedding, a kind of sedimentary layering that may be from
particle deposition by flowing wind, air or water currents.
However, the evidence from Opportunity’s first outcrop confirms what previous
observations of hematite deposits indicated — Mars was once a warm planet
with a lot of liquid water on or near its surface.
Read more about what the Mars rover team found at Geotimes
online.
Naomi Lubick
Links:
"NASA says Mars once drenched in
water," Geotimes Web Extra, March 2, 2004
For more Geotimes coverage of Mars, click here.
Back to top
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