Fascinating. I wonder how much water you would expect to find in a common Earth rock in the Sahara? Brent On 1/4/2013 6:05 AM, Henry Baker wrote:
FYI --
http://www.guardian.co.uk/science/2013/jan/03/mars-meteor-water-sahara-analy...
Mars meteorite 'Black Beauty' contains most water of any found on Earth, say scientists
Year-long analysis of rock found in Sahara and nicknamed Black Beauty also reveals it is one of the oldest known specimens
Associated Press in Los Angeles guardian.co.uk, Friday 4 January 2013 03.20 EST
Scientists are excited about a coal-coloured rock from Mars that landed in the Sahara desert. A year-long analysis revealed it is quite different from other Martian meteorites: not only is it older than most, it also contains more water.
The baseball-size meteorite, estimated to be 2bn years old, is strikingly similar to the volcanic rocks examined by the Nasa rovers Spirit and Opportunity on the Martian surface.
"Here we have a piece of Mars that I can hold in my hands. That's really exciting," said Carl Agee, director of the Institute of Meteoritics and curator at the University of New Mexico who led the study published online on Thursday in the journal Science.
Most space rocks that fall to Earth as meteorites come from the asteroid belt, but a number can be traced to the moon and Mars. Scientists believe an asteroid or some other large object struck Mars, dislodging rocks and sending them into space. Occasionally, some plummet through Earth's atmosphere.
Short of sending a spacecraft or astronaut to the red planet to haul back rocks, Martian meteorites are the next best thing for scientists seeking to better understand how Earth's neighbour transformed from a tropical environment to a frigid desert.
About 65 Martian rocks have been recovered on Earth, mostly in Antarctica or the Sahara. The oldest dates back 4.5bn years to a time when Mars was warmer and wetter. About half a dozen Martian meteorites are 1.3bn years old and the rest are 600m years or younger.
The latest meteorite, NWA 7034 – nicknamed Black Beauty – was donated to the University of New Mexico by an American who bought it from a Moroccan meteorite dealer last year.
Researchers performed a battery of tests on the meteorite and, based on its chemical signature, confirmed it was blasted to Earth from Mars. At 2.1bn years old, it is the second-oldest known Martian meteorite that formed from a volcanic eruption.
There is evidence that it was altered by water. Though the amount released during testing at high temperatures was small – 6,000 parts per million – it was still much more than other Martian meteorites. Scientists said this suggested there was interaction with water near the surface during a time when the planet was mostly dry and dusty.
More tests are under way to determine how long the rock floated in space and how long it had been sitting in the Sahara.
University of Alberta meteorite expert Chris Herd, who had no role in the research, said the find was welcome since most Martian rocks that rain on Earth tend to be younger. And the latest find does not appear to be too contaminated, he said.
"It's fairly fresh. It hasn't been subjected to a whole lot of weathering," said Herd.
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