Unusual Martian Rock Lands in Sahara Desert
About 110 Martian meteorites have landed on Earth. All but one fall into three categories — named after 3 space rocks. They are Shergotty, Nakhla, and Chassigny. In 2011 a Martian meteorite landed in the Sahara desert. NASA astronomers call it Black Beauty. It’s different from the other meteorites from Mars and could shed new light on Martian geology.
After Black Beauty was discovered a team of researchers from across the U.S. began intense study of the unusual meteorite. They discovered that it has a lot of water and it comes from the crust of Mars — probably ejected during a volcanic eruption. But most importantly, a group of scientists determined the meteorite formed 2.1 billion years ago during the beginning of the most recent geologic period on Mars, known as the Amazonian.
The associate administrator for NASA’s Science Mission Directorate says “The contents of this meteorite may challenge many long held notions about Martian geology.”
John Grunsfeld also says that the 11-ounce (320 grams) meteorite is a good match for surface rocks and outcrops NASA has studied remotely via Mars rovers and Mars-orbiting satellites. And now with the Curiosity rover on the surface of Mars looking for carbon and other signs of organic life this meteorite can provide a nice frame of reference.
The Black Beauty meteorite has a different chemistry compared to the three other classes of Martian meteorite. But NASA scientists say, “This unusual meteorite’s chemistry matches that of the Martian crust as measured by NASA’s Mars Exploration Rovers and Mars Odyssey Orbiter.”
The meteorite — known as NWA 7034 — is made of cemented fragments of basalt, rock that forms from rapidly cooled lava. The fragments are primarily feldspar and pyroxene, most likely from volcanic activity.
Carl Agee, director and curator at the University of New Mexico’s Institute of Meteoritics in Albuquerque and leader of the analysis team says, “This unique meteorite tells us what volcanism was like on Mars 2 billion years ago. It also gives us a glimpse of ancient surface and environmental conditions on Mars that no other meteorite has ever offered.”
Researchers theorize the large amount of water contained in NWA 7034 may have originated from interaction of the rocks with water present in Mars’ crust. The meteorite also has a different mixture of oxygen isotopes than has been found in other Martian meteorites, which could have resulted from interaction with the Martian atmosphere.
The research appears in the January 3 Science Express.