The discovery of water on ancient Mars isn't news, of course. Orbital observations and the work by the Mars Science Laboratory (MSL) and other NASA rovers have confirmed numerous locations where liquid water accumulated or flowed on ancient Mars. But until recently, those discoveries did little to advance our knowledge of whether those ancient waters might have provided suitable environments for ancient Martian microbes.
As explained in the National Geographic just a few years ago:
Mars likely had liquid water early in its past—but it was probably too acidic and oxidizing for life, scientists say.Now, the MSL on the Curiosity Rover has turned those assumptions on their head. Follow me out into the tall grass for the full story.
That's the latest news from the longer-than-expected visits to the red planet by NASA's rovers Spirit and Opportunity, said Andrew Knoll, a Harvard University researcher and member of NASA's Mars program.
"That's not a very good place to live, and it's a worse place for the kind of chemistry that we think gave rise to life on Earth," he said
Gale Crater is in an area with rocks about 4.2 billion years old. The lake, which scientists think existed a little more than 3.5 billion years ago, was roughly the size and shape of one of New York’s Finger Lakes. The freshwater lake may have come and gone, and sometimes been iced over, but the new research shows that the lake was not some momentary feature, but rather was part of a long-lasting habitable environment that included rivers and groundwater.An artist at NASA has given us an image of the probable size and location of the Gale Crater lake 3.5 billion years ago.
Previous discoveries by Mars rovers had suggested that the Red Planet once had surface and groundwater with the quality of battery acid, but the water in this lake looks much more benign.
“If we put microbes from Earth and put them in this lake on Mars, would they survive? Would they survive and thrive? And the answer is yes,” said John Grotzinger, a Caltech planetary geologist who is the chief scientist of the Curiosity rover mission.
Curiosity analyzed sediment from the bed of a long vanished lake and found that it harbors substantial amounts of organic matter of some sort, although scientists have pulled back from attributing it to life.Oh yeah. About that swimmin' hole? Bring a wet suit and something to breath. Fresh water or not, it would have been pretty cold and short on O2.
It is thought possible that over 4 billion years ago Mars may have had enough fresh water on its surface to generate clay minerals which may have supported life but that it underwent drying that left any remaining water too acidic and briny to support life.
Curiosity has also determined how recently surface rocks have been exposed by erosion.
“Our mission is turning a corner. We are beginning to map a way forward, a way to explore deliberately for organic matter,” Said John Grotzinger, a Curiosity project scientist at the California Institute of Technology in Pasadena.
For all things Mars on Daily Kos, visit Kossacks on Mars.