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View Full Version : Finding "Tightens the Noose on the Possibility of Life" on Mars



Fraser
2008-Feb-16, 09:00 PM
So far, the Mars Exploration Rover (MER) Mission has turned up very little evidence that there is, or was, life on the Red Planet. Even more bad news is on the way from data sent back from NASA rovers Opportunity and Spirit - it would seem that the planet is "too salty" for even the [...]

More... (http://www.universetoday.com/2008/02/16/finding-tightens-the-noose-on-the-possibility-of-life-on-mars/)

Noclevername
2008-Feb-16, 10:52 PM
As was pointed out on the other thread about this (http://www.bautforum.com/life-space/70395-mars-great-salt-lick.html), It's too salty for Earth life, that is, life adapted to Earth conditions. Presumably Mars life would be adapted to Mars conditions. And the article says that even "a handful" of our terrestrial extremophiles might survive there, so it's not entirely unlivable even for those used to easy living on the Blue Planet.

Ronald Brak
2008-Feb-16, 11:16 PM
Earth has salty oceans, but I've also noticed that it seems to have large bodies of water known as fresh water lakes. I would conjecture that in the past it is possible that such bodies existed on mars as well.

Oh, and I has got algae in my salt.

JonClarke
2008-Feb-17, 06:07 AM
Earth has salty oceans, but I've also noticed that it seems to have large bodies of water known as fresh water lakes. I would conjecture that in the past it is possible that such bodies existed on mars as well.

Oh, and I has got algae in my salt.

I agree. It's a completely unjustified conclusion given the very limited data we have. We know that one ancient seidmentary sequence on Mars was hypersaline from rover studies. We suspect that there are other such deposits from orbital data. We also know that there are many sedimentary deposits on Mars that do not have evaporite signatures.

Likewise we know that there is jarosite on the Martian surface at one location indicating low pH. We do not know when this jarsoite formed and what it's relationship is with the sedimentary conditions. it is possible, perhaps likely, that the acidity that formed the jarosite had nothing to do with deposition and is the result of much later weatering.

It is really annoying when competent scientists says this sort of stuff.

Jon

Ronald Brak
2008-Feb-17, 06:23 AM
There also seems to be an assumption that oceans are necessary for life. But we don't know where life started on earth or if oceans were required. We can't even be certain that life did start on earth.

Noclevername
2008-Feb-17, 06:30 PM
It is really annoying when competent scientists says this sort of stuff.


The body that made this announcement was the American Association for the Advancement of Science.


AAAS permit[s] all people regardless of scientific credentials to join

So it's like a scientific Wikipedia.

JonClarke
2008-Feb-18, 07:58 AM
Except that person quoted wasn't just anybody, it was Andy Knoll, a leading authority on precambrian fossils and on the MER science team. He shoud know better.

Jon

schlaugh
2008-Feb-18, 03:56 PM
Well, to be precise, he said that known Earth life would have trouble surviving. But he does not say (because it can't be determined) if life could evolve and adapt within those salty conditions.

"It was really salty - in fact, it was salty enough that only a handful of known terrestrial organisms would have a ghost of a chance of surviving there when conditions were at their best." - Dr Andrew Knoll, a biologist at Harvard University, speaking at the AAAS meeting.