LOS ANGELES (AP) - NASA's Curiosity rover has uncovered signs of an ancient freshwater lake on Mars, which scientists say could have been a perfect spot for tiny primitive organisms to flourish if they ever existed on the red planet.
The watering hole near the Martian equator existed about 3.5 billion years ago around the time when life evolved on Earth. Scientists say the Martian lake was neither salty nor acidic, and contained life-friendly nutrients.
"This just looks like a pretty darn ordinary Earth-like lake in terms of its chemistry," said project scientist John Grotzinger of the California Institute of Technology. "If you were desperate, you could have a drink of this stuff."
The lake, about the size of a small Finger Lake in upstate New York, likely was around for tens of thousands - perhaps hundreds of thousands - of years. Even when the lake dried up, scientists said microbes could have migrated underground, and existed for potentially tens of millions of years.
It's not known whether simple life forms ever took hold on Mars and Curiosity lacks the tools to search for any fossilized microbes. It can only analyze the chemical makeup of rocks and soil.
The findings were published online Monday in the journal Science and presented at the American Geophysical Union meeting in San Francisco.