Lake on Mars could harbor life

- The Curiosity NASA probe found traces of an ancient freshwater lake on Mars could have hosted a myriad of microorganisms for tens of millions of years , much longer than scientists had thought , according to new research suggests.
The lake near the Martian Ecuador existed some 3,500 million years ago . Scientists said it was not salt or acid and containing nutrients, a perfect match to host microbes.

"In terms of chemical composition seems a good standard ground lake ," said scientist John Grotzinger project, the California Institute of Technology .
The lake probably existed for tens of thousands, perhaps hundreds of thousands - of years. Even when dried , scientists speculate that the possible microbes may have migrated underground, extending the period of potentially habitable tens of millions of years. But no instrumental probe to find fossilized microbes .

 The findings were published Monday in the journal Science and presented at the meeting of the American Geophysical Union in San Francisco.
"The new results decisively reinforce the idea that it was possible that there was past life on Mars," said planetary scientist David Page at the University of California, Los Angeles, in an email .
Page , who is not involved in the project, adding that "the question of whether there was life on Mars remains open ."
The red planet has a dusty and rugged appearance without signs of water on the surface. It was not always a desert, at the beginning of its history was more tropical, with streams and rivers. With plenty of water, scientists believe it was a place where he could have developed a primitive life that feed on rocks and minerals , similar to Earth microorganisms hiding in caves and underwater fumaroles.

 Change in climate
About 3,500 million years ago, Mars experienced a change and intense volcanic activity. The Spirit and Opportunity probes, NASA found geological evidence that water had at the time, but had a high acid content and was considered too caustic to allow life.
Scientists believed that much of the world was full of water until the acid Curiosity found signs of an old water bed with a pH (alkalinity ) neutral near where he landed on the Martian surface.
And when analyzing a sedimentary rock, driven to nuclear energy probe found evidence of a large body of water - the most ancient lake - which was theoretically potable water , with some of the basic ingredients of life such as carbon, hydrogen, oxygen , sulfur , nitrogen and phosphorus.