A new Martian meteorite named Yamato 000593 revealed evidence of the history of water movement in Mars, thus renewing arguments about the past habitability of the red planet.
Scientists from NASA's Jet Propulsion Laboratory (JPL) and Johnson Space Center in Houston led by Everett Gibson, Kathie Thomas-Keprta, and David McKay analyzed a rock that was discovered on the Yamato Glacier in Antarctica during the Japanese Antarctic Research Expedition in 2000.
They believe that the rock, which was formed from a lava flow on Mars around 1.3 billion years ago, was ejected from the surface of Mars when an impact happened on Mars about 12 million years ago. Upon ejection, it traveled through space and landed on Antarctica approximately 50,000 years ago.
It was also distinguished as a Martian meteorite because the rock's silicate minerals contain oxygen atoms and trapped atmospheric gases.
After analyses of the 13.7-kilogram meteorite, the scientists found two distinctive sets of features. First is the structure of the tunnel and micro-tunnel which are consistent with bio-alteration textures caused by bacteria-basaltic material interaction. Second is the set of features that consists of nanometer-to-micrometer-sized spherules that that are situated between layers in the rock.
These structures and compositional features, which are possibly due to biotic activities in the meteorite, suggest the presence of biological processes on Mars.
"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," said Gibson in the press release. "The planet is revealing the presence of an active water reservoir that may also have a significant carbon component."
"The small sizes of the carbonaceous features within the Yamato 000593 meteorite present major challenges to any analyses attempted by remote techniques on Mars," she added.
This study was published in the February 2014 issue of Astrobiology.
