Martian rock from Sahara desert unlike others

Jan 03, 2013 by Alicia Chang
This image provided Carl Agee, University of New Mexico, shows a rock from Mars that landed in the Sahara Desert. An examination of the Martian meteorite known as NWA 7034 determined it is 2.1 billion years old and is water-rich. (AP Photo/University of New Mexico, Carl Agee)

Scientists are abuzz about a coal-colored rock from Mars that landed in the Sahara desert: A yearlong analysis revealed it's 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 2 billion 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 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 neighbor 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 4.5 billion years to a time when Mars was warmer and wetter. About half a dozen Martian meteorites are 1.3 billion years old and the rest are 600 million 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 that it was blasted to Earth from Mars. At 2.1 billion years old, it's the second-oldest known Martian meteorite that formed from a volcanic eruption.

There's also 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 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, who had no role in the research.

Explore further: After early troubles, all go for Milky Way telescope

More information: "Unique Meteorite from Early Amazonian Mars: Water-rich Basaltic Breccia Northwest Africa 7034," by C.B. Agee, Science, 2013.

Journal reference: Science search and more info website

4.5 /5 (11 votes)
add to favorites email to friend print save as pdf

Related Stories

Moroccan desert meteorite delivers Martian secrets

Oct 11, 2012

(Phys.org)—A meteorite that landed in the Moroccan desert 14 months ago is providing more information about Mars, the planet where it originated. University of Alberta researcher Chris Herd helped in the ...

First meteorite linked to Martian crust

Jan 03, 2013

After extensive analyses by a team of scientists led by Carl Agee at the University of New Mexico, researchers have identified a new class of Martian meteorite that likely originated from the Mars's crust. ...

Scientists confirm rocks fell from Mars (Update)

Jan 17, 2012

They came from Mars, not in peace, but in pieces. Scientists are confirming that 15 pounds of rock collected recently in Morocco fell to Earth from Mars during a meteorite shower last July.

Extensive water in Mars' interior

Jun 21, 2012

Until now, Earth was the only planet known to have vast reservoirs of water in its interior. Scientists analyzed the water content of two Martian meteorites originating from inside the Red Planet. They found ...

Recommended for you

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Jeddy_Mctedder
1 / 5 (3) Jan 03, 2013
I dont care how much geology has discovered. Not a single rock sample directly recovered from mars has ever been returned to earth fir human study.
Screw the analytic spectrometer results from a few rovers on the surface of mars. I refuse to believe we have reliable methods of atributing rocks on earth to mars regardless of isotope matching.

I think we can safely call thproposed martian origins of these samples a standin hypothesis