Mar 03, 2014 11:27 AM EST
Meteorite On Earth Revives Debate Over Life On Mars
Scientists from NASA's Johnson Space Center in Houston have found evidence of water movement in a Martian meteorite, reviving debate in the scientific community over life on Mars, Counsel and Heal reported.
The 13.7 kilogram meteorite, known as Yamato 000593, landed in Antarctica around 50,000 years ago. Researchers said newly discovered different structures and compositional features within the meteorite suggest biological processes might have been at work on Mars hundreds of millions of years ago.
"While robotic missions to Mars continue to shed light on the planet's history, the only samples from Mars available for study on Earth are Martian meteorites," lead author Lauren White said in a statement. "On Earth, we can utilize multiple analytical techniques to take a more in-depth look into meteorites and shed light on the history of Mars."
Analyses found that the rock was formed about 1.3 billion years ago from a lava flow on Mars. Around 12 million years ago, an impact occurred on Mars which ejected the meteorite from the surface of Mars. The meteorite traveled through space until it fell in Antarctica about 50,000 years ago, Counsel and Heal reported.
The meteorite is distinguished from other meteorites and materials from Earth and the Moon by the composition of the oxygen atoms within the silicate minerals and trapped Martian atmospheric gases.
The team found two distinctive sets of features associated with Martian-derived clay. They found tunnel and micro-tunnel structures that thread their way throughout Yamato 000593. The observed micro-tunnels display curved, undulating shapes consistent with bio-alteration textures observed in terrestrial basaltic glasses, previously reported by researchers who study interactions of bacteria with basaltic materials on Earth.
The second set of features consists of nanometer- to-micrometer-sized spherules that are sandwiched between layers within the rock and are distinct from carbonate and the underlying silicate layer.
"The unique features displayed within the Martian meteorite Yamato 000593 are evidence of aqueous alterations as seen in the clay minerals and the presence of carbonaceous matter associated with the clay phases which show that Mars has been a very active body in its past," Scientist Everett Gibson said in a statement. "The planet is revealing the presence of an active water reservoir that may also have a significant carbon component."
White said the samples offer clues to the past habitability of Mars.
"This is no smoking gun," White said. "We can never eliminate the possibility of contamination in any meteorite. But these features are nonetheless interesting and show that further studies of these meteorites should continue."
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