http://www.japantimes.co.jp/news/2013/03/13/world/mars-rover-finds-key-indicators-of-water/Mars rover finds key indicators of water
AFP-JIJI
MAR 13, 2013 PRINT SHARE
WASHINGTON – Analysis of Mars rocks by the Curiosity rover uncovered the building blocks of life  hydrogen, carbon and oxygen  and evidence the planet could once have supported organisms, NASA said Tuesday.
“A fundamental question for this mission is whether Mars could have supported a habitable environment,†said Michael Meyer, lead scientist for NASA’s Mars Exploration Program. “From what we know now, the answer is yes.â€ÂÂ
At a televised news conference, the NASA team said this is the first definitive proof a life-supporting environment had existed beyond Earth.
“There are places we’ve suggested could be habitable, but we haven’t measured there,†said Dave Blake, principal investigator for Curiosity’s Chemistry and Mineralogy investigation.
Curiosity, a six-wheeled robot with 10 scientific instruments on board, is the most sophisticated vehicle ever sent to another planet.
The sample was drilled from sedimentary bedrock in an area that previous research had shown to be either part of an ancient river system or lake bed.
It was found to contain clay and sulfate minerals as well as other chemicals.
Based on the analysis of those chemicals, researchers were able to determine that the water in which the rocks were formed was of a relatively neutral pH  not overly salty, acidic or oxidizing.
“We have found a habitable environment that is so benign and supportive of life, that probably if this water was around and you had been there, you would have been able to drink it,†said John Grotzinger, a Curiosity project scientist from the California Institute of Technology.
Speaking at the same news conference, one of NASA’s top officials, John Grunsfeld, said the discovery makes him “feel giddy.â€ÂÂ
He said the new data helps add to the picture of how the red planet may have looked in a previous era, with possible freshwater lakes and a snow-capped Mount Sharp.
But it wouldn’t have looked like that any time recently, the researchers cautioned.
Although it is hard to confirm an exact date, it was probably at least 3 billion years ago, Grotzinger said.
Researchers also noted that future rock samples will be needed to confirm these results, because it is possible that residual carbon on the drill affected the analysis.
But “the instrument is working beautifully,†said Paul Mahaffy, principal investigator for Curiosity’s Sample Analysis at Mars team.
The group is already planning when and where to take the next rock samples, as well as eyeing the rover’s route to nearby Mount Sharp, where mineral analysis should help with dating calculations.
On an two-year mission, the $2.5 billion Curiosity, which is nuclear-powered, has been exploring the planet’s surface since its dramatic landing on Aug. 6.
Scientists do not expect Curiosity to find extraterrestrials or living creatures  and indeed, as they said Tuesday, the rover does not have the capability of identifying microbial life or fossils, even if they were present today.
However, the analysis of soil and rocks is aimed at finding evidence Mars may have supported life in the past.