Mars Rover Curiosity Finds Ancient Lakebed 74
astroengine writes "The site where NASA's Mars rover Curiosity landed last year contains at least one lake that would have been perfectly suited for colonies of simple, rock-eating microbes found in caves and hydrothermal vents on Earth. Analysis of mudstones in an area known as Yellowknife Bay, located inside the rover's Gale Crater landing site, show that fresh water pooled on the surface for tens of thousands — or even hundreds of thousands — of years. 'The results show that the lake was definitely a habitable environment,' Curiosity lead scientist John Grotzinger, with the California Institute of Technology, told Discovery News. The finding was announced at the American Geophysical Union conference in San Francisco."
genesis of life (Score:1, Insightful)
Now although there might have existed water on Mars, and even oceans, the reality is that the chance that life had been able to start on Mars before it dried up and turned into a reddish rock is zero.
Re:genesis of life (Score:5, Insightful)
Mars had an atmosphere before it's core cooled and it lost it's magnetic field, so it would have been significantly more hospitable way back in the day. It wasn't always a "dried up" "reddish rock".
Re:Microbes require hundreds of Myrs to evolve (Score:5, Insightful)
Tens of thousands of years just ain't gonna cut it. Water may be necessary for life, but it is not sufficient.
Tell that to the iron respirating microbes of Blood Falls [wikipedia.org] that were in their transient little pool breathing oxygen normally until one sudden winter the surface froze and never receded. All they "needed" was a pool of water and some chemically active elements, like iron and sulphur -- both present on Mars.
Transient lakes are not a good environment - anything that gets started gets nipped in the bud when the lake dries up.
You need a STABLE environment for hundreds of millions of years, and probably oceans, not lakes. Find some banded iron formations and we'll talk.
You're in luck! We found a formation right next to Mars! You're living on it! And we even have rocks from Mars on Earth -- ejecta from impacts -- and estimate that tons of Earth has been spread about the solar system, possibly seeding live just about anywhere that could support it.
Don't get me wrong, I'm just as sceptical as the next person. I'll rightly dismiss any claim without evidence, but I refuse to have a closed mind to possibilities for the very same reason: Every time we've declared places on Earth devoid of life, we've found it thriving there. Used to think life couldn't exist at the bottom of the ocean, wrong. Used to think no life could survive subduction into the crust, wrong. We've had to re-define what life "needs" to survive so many times it's more truthful to say, "we're not really sure where life can't survive." So, if you make an unevidenced claim like, "You need a STABLE environment for hundreds of millions of years" -- I'll give you the same sceptical middle finger: Fucking Prove it, or you're full of bullshit.
Re:genesis of life (Score:3, Insightful)
Latest evidence is that life on Earth started a lot faster than that, maybe even less than half a billion.
Mars cooled faster than Earth (in part because of the incident which led to Earth's Moon), and early Mars had a magnetic field and relatively thick atmosphere. It took over a billion (maybe 1.5, maybe as long as 2) for Mars to dry up.
It's entirely possible that life started on Mars before it did on Earth. It's even possible (unlikely, but not impossible) that life started on Mars first then transferred to Earth via meteorite.