Ancient Mars Could Have Supported Life 81
sighted writes "NASA is announcing that analysis of a rock sample collected by the Curiosity rover shows ancient Mars could have supported living microbes. Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater last month. The announcement quotes Michael Meyer, lead scientist for NASA's Mars Exploration Program: 'A fundamental question for this mission is whether Mars could have supported a habitable environment. From what we know now, the answer is yes.'"
You can see it in the rock. (Score:5, Interesting)
If you just look at the photo [nasa.gov] of the powdered rock sample, you can see it doesn't look dusty red, like soil samples and rocks from elsewhere on Mars [nasa.gov]. The red is hematite, a sign of high-oxidation. The grey of Gale Crater says right away that this environment is different, less-oxidized, and probably also a good deal less acidic.
Could have been.... (Score:5, Interesting)
Could have been....
One aspect of the possibility of life on Mars that is rarely discussed is the fact that there are still a couple of other characteristics of Mars in it's current state that preclude life, as we know it--a lack of a strong magnetic field and the permanent sequestration of CO2 in the ground.
Mars is dead. The core of Mars has long since cooled, leaving it with a much thicker solid mantle then Earth currently has. It may have similar "ingredients" to Earth, but those ingredients on Mars have stopped flowing--much of the magnetic field on Earth is a result of not only the ferrous content, but the motion of that content within the Earth, motion that can only occur in non-solids.
Why is this important? Without a swirling interior, you have a much weaker magnetic field protecting the planet from solar radiation, radiation that is harmful to life. Another more important aspect is the effect of a magnetic field in terms of solar pressure (the same pressure that propels a "solar sail") on the atmosphere of Mars. Here on Earth, our magnetic field counters that pressure from solar winds and literally keeps our atmosphere from "blowing" away. There are other things that keeps our atmosphere around (ha!), like gravity, but protection from solar pressure is important--the solar pressure exerted on Mars is greater then the countering effect generated by Mars' magnetic field.
There is nothing to keep Mars' atmosphere from blowing away.
http://www-ssc.igpp.ucla.edu/personnel/russell/papers/mars_mag/ [ucla.edu]
All of that being said, any CO2 released from the ground--CO2 that would create a greenhouse effect--doesn't stay in the atmosphere. The idea of Terra-forming Mars wouldn't work--we could bring the entire atmosphere of Earth along with us to Mars and it would simply blow away into space.
But, Tardigrades have survived in space a very long time...
http://en.wikipedia.org/wiki/Tardigrades [wikipedia.org]
Re: Could have been.... (Score:5, Interesting)
Right, but if Mars was one warm and squishy, then it gradually cooled off and hardened internally.
So each successive generation would have selective pressure to survive a slightly lower temperature, a slightly weaker em field, a slightly more hostile environment. That's happening in geological time, and it's perfect for an evolutionary development of a species that could survive there.
It's unlikely though, and until they see fossils or movement, then it's still just potential. If we all lived up to our potential half of us would be living in space.
It could right now. (Score:4, Interesting)
As far as we know their is life under the ice right this moment, where their might be large lakes or seas of liquid water. This life could even be fish like.
Hell we have bacteria living in ice on earth, we might find the same thing there.
Mars was very earth like far before Earth became more than a ball of molten rock and metal. If life is at all common, it probably had it, as it probably had about the same chances of it forming.