Not good for life, it seems.As disappointing as this news is, it's not really surprising to me.

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We want our children to go to the planets. Burt Rutan 6/21/04
Tuckers! Science! Automotive Oddities! Boycott Trek XI! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither.

Well, good thing Earth life wasn't required to evolve there. Martian life might have a negative opinion of briney alkaline conditions.

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"The beauty of that discussion of averages is that you don't have to be an expert in Apollo or in photography in order to see where this time study "analysis" breaks down. You just have to be, well...not an idiot." -JayUtah

This is, indeed, disappointing, but not surprising. We must remember that life of any kind is, at its heart, a story about chemistry. If the chemistry isn't there, you can't have life.

But this does paint an increasingly confident picture about Mars that finds its first epoch a place of limited microbial possibilities, followed by four billion years of sterility. If there ever was life on Mars, its likely going to be decades before we ever know for certain.

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Anything may be possible, but not everything actually is. Some things are true and some things are not. Wisdom is knowing the difference.

No doubt Martians would say Earth is uninhabitable because our water is too pure.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Especially considering that we have only one form of biology to compare anything to.

The biochemistry of life in this universe is pretty much a given constant. The bonds that hold things together and the mechanisms that replicate molecules are governed by a chemistry and physics that have known physical limits. Get things too salty, too acid or too alkaline and this chemistry can't hang together. It's a fact of life.

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Anything may be possible, but not everything actually is. Some things are true and some things are not. Wisdom is knowing the difference.

I suspected Mars was very salty. There are numerous signs that liquid water existed on its surface, yet it's average temperature was below zero.

The water had to be salty, even ground water.

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Fields of Space

LOGIC, n.
The art of thinking and reasoning in strict accordance with the limitations and incapacities of the human misunderstanding.

In the Year 2525.

"One small step for (a) man. One giant leap for mankind".

If an astronaut doesn't need good grammar, niether does you.

Host of Seraphim

I suspect that we will find, and actually have already found, that conditions on Mars varied widely not only through time but in different locations.

Mars has a very complex geologic history which we have only just begun to understand, and our robotic geologists have only explored the tiniest of areas. Most of the surface area is boring in that it is covered with dust and volcanic rocks, but there are scattered locations that sure look extremely interesting.

Saying at this point that we know what global conditions were on Mars is presumptive.

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"I'm as accurate as any psychic. And I'm a cartoon!" -- Squidward

"Arrrgh, the laws of physics be a harsh mistress!" -- Bender

This does fit very well with what we've learned about mars so far; A brief window of borderline habitability followed by increasing salinity, acidy and paucity of water followed by the hyper arctic desert conditions we see today.
But.. we've found life on earth in conditions of utter cold, hyper salinity and acidity. For microbes surviving in arctic ice, or the mcmurdo valleys pretty much the only water available is very salty or acidic, and very scarce in liquid form. If there ever was life there I dont think it's unthinkable that some hardy microbe found a way to survive, even as conditions turned very bad indeed. And lets not forget that there are places in the outer solar system that show signs of being much more habitable than mars ever was, even today. So I don't see why this should be taken as too great a disapointment, i'm going to take it as an object lesson in keeping what I hope for realistic, and carry on hopeing!

Very true! And don´t forget the black smokers:
http://en.wikipedia.org/wiki/Black_smoker

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IF I´m wrong you MAY be right

Die Lücke, die wir hinterlassen, ersetzt uns vollkommen (Carl Heinz Schroth)

What does this mean for the prospects of terraforming Mars?

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"What you think you thought you saw you did not see." Agent J, MiB - Manhatten Bureau

It's not promising. But keep in mind that the conditions of early Earth would have looked pretty daunting to us, too.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

From the Universe Today article on salty Mars: So it's possible that even some life adapted to Earth conditions could survive there, for a time. Life adapted to those conditions in the first place would have a much easier time.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Earth's water 'aint uniformly salty. We have these things called lakes. And there seems to be an assumption that martian life needs oceans. We don't know that life started in oceans on earth or that they are required for life.

If The core of Mars then, was half the celcius temperature of Earth's core now; most of the water may have been below the ground, and only slightly salty.
After most of the atmosphere was gone, rain and snow would stop (except perhaps at the poles). Any water that reached the surface would evaporate, producing salt flats in only a few thousand years. The water below the ground may still be only slightly salty. Neil

I wonder if ice at the bottom of the ice caps ever melts, like the lakes in Antartica.

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"I'm as accurate as any psychic. And I'm a cartoon!" -- Squidward

"Arrrgh, the laws of physics be a harsh mistress!" -- Bender

To play devil's advocate...

1.) This is only one locale on Mars.

1.) What we really need to know is how long conditions were like this, something I don't think can be answered until we have good radiometric dates for Meridiani--let alone for Mars in general.

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"He fell for her like his heart was a mob informant and she was the East River."

--Anonymous

I must say I get very frustrated by stories like this. It illustrated Mark Tawain's dictum beautifully:

There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.

It is taking data from one succession, the Burns Fm at Merdiani and exptrapolating to an entire planet. It's taking a tiny fraction of martian history and applying it to the whole history.

Imagine a future earth from which all obvious life has vanished. A probe from the ngrzz'l species of Formalhaut lands on an evaporite deposit deposit (say the Summerville Fm in Utah) and concludes because of the evidence for hypersaline conditions that life was unlikely on the ancient Earth. Meanwhile, just up section is the Morrison Formation, with some of the best dinosaur bones on Earth.

I wish people would stop saying this sort of stuff. People like Andy Knoll should know better.

Jon

It is possible that a region of 1% or less may have been hospitable enough to support primitive life. I presume that we will not be able to rule out past life on Mars ever, even if all of Mars has been studied and documented. If indeed evidence of life is found, it would surely alter the prospects of life elsewhere throughout the universe. The debate will then be is life very possible throughout the galaxy or is the solar system (as opposed to earth alone) just unique.

That's right, Jon.

It should be remembered that there is still the evidence for earlier, less acidic (and less salty?) water, which left behind the clay mineral deposits. Ray Arvidson of the MER team mentioned this again in this recent December 10, 2007 update:

http://marsrovers.jpl.nasa.gov/newsr.../20071210a.htm

"We see evidence from orbit for clay minerals under the layered sulfate materials," said Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the rovers' science payload. "They indicate less acidic conditions. The big picture appears to be a change from a more open hydrological system, with rainfall, to more arid conditions with groundwater rising to the surface and evaporating, leaving sulfate salts behind."

ALL of these observations must be considered...

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The Meridiani Journal
a chronicle of planetary exploration
web.mac.com/meridianijournal