Saturday, January 5, 2013

All about the Red Planet Mars: Yet another meteorite contains water



WASHINGTON -- NASA-funded researchers analyzing a small meteorite that
may be the first discovered from the Martian surface or crust have
found it contains 10 times more water than other Martian meteorites
from unknown origins.

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 11 ounces (320 grams). After more than a year
of intensive study, a team of U.S. 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."

The meteorite is an excellent match for surface rocks and outcrops
NASA has studied remotely via Mars rovers and Mars-orbiting
satellites. NWA 7034's composition is different from any previously
studied Martian meteorite. The research is published in Thursday's
edition of Science Express.

"The contents of this meteorite may challenge many long held notions
about Martian geology," said John Grunsfeld, associate administrator
for NASA's Science Mission Directorate in Washington. "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."

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 and director and curator at
the University of New Mexico's Institute of Meteoritics in
Albuquerque. "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."

The research team included groups at the University of California at
San Diego and the Carnegie Institution in Washington. Experiments
were conducted to analyze mineral and chemical composition, age, and
water content.

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.

Most Martian meteorites are divided into three rock types, named after
three meteorites; Shergotty, Nakhla, and Chassigny. These "SNC"
meteorites currently number about 110. Their point of origin on Mars
is not known and recent data from lander and orbiter missions suggest
they are a mismatch for the Martian crust. Although NWA 7034 has
similarities to the SNC meteorites, including the presence of
macromolecular organic carbon, this new meteorite has many unique

"The texture of the NWA meteorite is not like any of the SNC
meteorites," said co-author Andrew Steele, who led the carbon
analysis at the Carnegie Institution's Geophysical Laboratory. "This
is an exciting measurement in Mars and planetary science. We now have
more context than ever before to understanding where they may come

The research was funded by NASA's Cosmochemistry Program and
Astrobiology Institute, part of the Planetary Science Division in the
Science Mission Directorate at NASA Headquarters. The research also
was supported by the New Mexico Space Grant Consortium in Las Cruces,
and the National Science Foundation in Arlington, Va.

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