“Black beauty” meteorite gives insights to Mars history
A 2-billion-year-old dark lump of rock that landed in
Sahara desert is actually a new type of Martian meteorite, containing 10
times more water than usual, scientists say.
This
new class of meteorite was found in 2011 in the Sahara Desert.
Designated Northwest Africa (NWA) 7034, and nicknamed “Black Beauty,” it
weighs approximately 320 grams.
After more than a
year of intensive study, a team of US 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
age of NWA 7034 is important because it is significantly older than
most other Martian meteorites,” said Mitch Schulte, program scientist
for the Mars Exploration Program at NASA Headquarters in Washington.
“We now have insight into a piece of Mars’ history at a critical time in its evolution,” said Schulte.
The
meteorite is an excellent match for surface rocks and outcrops NASA has
studied remotely via Mars rovers and Mars—orbiting satellites, NASA
said in a statement.
NWA 7034’s composition is
different from any previously studied Martian meteorite. The research is
published in journal of Science Express.
“The
contents of this meteorite may challenge many long held notions about
Martian geology,” said John Grunsfeld, associate administrator at NASA’s
Science Mission Directorate.
“These findings also
present an important reference frame for the Curiosity rover as it
searches for reduced organics in the minerals exposed in the bedrock of
Gale Crater,” he said
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.
This unusual meteorite’s chemistry
matches that of the Martian crust as measured by NASA’s Mars Exploration
Rovers and Mars Odyssey Orbiter.
“This Martian
meteorite has everything in its composition that you’d want in order to
further our understanding of the Red Planet,” said Carl Agee, leader of
the analysis team.
“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,” said Agee.
Researchers theorise 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.
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