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Post by mrsonde on Oct 31, 2012 17:55:29 GMT 1
By the by...ETHANE...not convinced that is required to nail the critter. It can be a product in certain reactions involving the production of methane but not in great quantity and not as a marker of life in any form. There is no known example of a methanogen that does not also produce ethane in the presence of CO2, water, and ionising radiation. Given Mars' far greater exposure to UV and ionic bombardment from the Solar Wind, this would be even more evident there. What you're hypothesising is an entirely unknown form of life. Not impossible, of course, on a different planet.
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Post by docstrangebrew on Oct 31, 2012 22:33:39 GMT 1
Under some circumstances some methanogens can undergo extremely complicated reductions that occur in organic chemistry where trace Ethane is produced, but on Mars hydrocarbon chemistry seems at best rare and at worst non-existent. Besides below 4 celsius you get no activation at all. Average temp is regarded as about -55 C although sometimes in the summer season a day can boast 20C for a short time but at night the temp always hits the lows of around -73C. This is not conducive to the chemistry you envisage. Further more I thought you did not believe water has ever been part of the martian environment and that is seemingly a must have for the process to redox.
Sorry but I do not consider Ethane being very important in this context.
Just come across this message from NASA...
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Post by mrsonde on Nov 1, 2012 8:03:48 GMT 1
Under some circumstances some methanogens can undergo extremely complicated reductions that occur in organic chemistry where trace Ethane is produced Under all the circumstances we know of. That's what this thread that you started is about. Methane on Mars. Where did it come from? Right? The activation proposed is through ionising radiation, not infrared absorption. Huh? Of course water is part of the Martian environment. That's been known since the 70s. It's in the atmosphere, and can condense from there as ice into the polar caps. Water's everywhere, throughout all of space. What I've said there is no clear evidence of is any liquid water flowing or ever having flowed on the surface - the sine qua non of a biosphere functioning or ever having existed for such a proposed active biological process to have evolved. Life absolutely needs water in a liquid state to exist, as far as all our experience goes. But I'm not being dogmatic - it's just possible. Some proto-lifeform, able to absorb water vapour from the atmosphere, breathe in CO2 and out methane, using some hitherto undiscovered electron transport chain for its food. Maybe it's a Michael Crichton type crystalline organism, able to split water using silica. It's all speculation at this stage, imo. And until there was a plausible non-biological source for the methane, necessary speculation. It may become so again, if you're right; in which case, I agree, it'll be a fascinating press conference. Forget it then. Clearly, if you're proposing an entirely new form of life any terrestial classifications do not necessarily apply.
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Post by docstrangebrew on Nov 1, 2012 20:49:20 GMT 1
Under all the circumstances we know of That unfortunately is not true.. 'There is no obvious reason why all methanogenes should produce CH3CH3 on earth. It looks quite the opposite. And definitely there is no reason whatsoever, why a CH4 producing pathway of life on another planet should always produce CH3CH3.' Please cite your information. mine is from a Bio-Chemist! Well yes and no...the thread was started in order to draw folks attention to the fact that such a important experiment and test should have be so closely guarded by NASA...the conclusion I came to was that they had found a significant CH^4 spike and were confirming and cranking up the mass spec package in SAM to find the isotopic ratio...a light Carbon number would indicate microbiological and tied in with the summer season plumes would tie up quite nicely. I am prepared for geological source but that is less likely given the the planetary formation, but I am prepared for that all the same! Still needs an ambient temperature above 4* C and below 80*C What do you think activation energy means in this context? Then your knowledge and appreciation of geology is rather thin, the geology is classic water carved by any known flowing water driven process observed on Earth. And if not water then what? Wind is not powerful enough to move the conglomerates photographed, and certainly would not carve channels or flood plains as witnessed. That is true but it has been fun! No I am not proposing that although you seem to be assuming that...Ethane is neither here nor there on Mars...it is not as freely produced as you want to suggest! And it is not indicative of metabolism in the range of Methanogens that is available! Some do indeed produce Ethane but with catalysts to pave the redox pathway, but certainly not ALL!
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Post by docstrangebrew on Nov 2, 2012 20:32:11 GMT 1
So my conclusion was wrong totally...No methane detected up until now! But it also means that meteorites being UV dosed and releasing methane is also not the mechanism in operation. It was obviously far to simple an assumption. But it does mean that there is a mechanism that is not understood as yet is in play. A decade of remote sensing has confirmed that methane does occur in the Martian atmosphere, it would be rather a long shot to declare all such observations are in error. So what do we have...a little more then previous actually! We have VARIABILITY in CH^4 concentration on Mars. Which was what I hoped would be the case, although I did not expect a zero reading is true but we have what we have! So 'if' the observation from the past are valid, and there is no reason to doubt the hardware or the analysis, it is to be expected that sooner or later there will be a surface spike recorded. Even if a plume erupts on the far side of the planet atmospheric movement will distribute it and a month will see the concentration register in SAM. From some angles that might be the best evidence as yet that the plumes are generated seasonally and that there is another dimension...this could well be evidence that there is an active methane 'sink' on Mars. A 'sink' that reacts to seasonal conditions. What mechanism reacts to seasonal variations with some alacrity, metabolism springs to mind, rest of the darker colder time stasis! Perfect adaptation to environment...evolutionary pragmatism strikes again...maybe! Also it asks another relevant question, how comes it dissipates so quickly? 300 yrs is the accepted lifetime, this stuff lasts a few months, something really radical is happening there also! NASA are puzzled, damn it all so am I, but this is probably how it was going to be anyway, no one said ET had to behave But like all things time will tell and NASA is surprisingly on the case, so they say, methinks they are well intrigued, how can anyone not be?
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Post by mrsonde on Nov 7, 2012 14:49:06 GMT 1
Under all the circumstances we know of That unfortunately is not true.. 'There is no obvious reason why all methanogenes should produce CH3CH3 on earth. It looks quite the opposite. And definitely there is no reason whatsoever, why a CH4 producing pathway of life on another planet should always produce CH3CH3.' Please cite your information. mine is from a Bio-Chemist! Well, then, perhaps you should ask your biochemist what the other methanogens are that we know of that do not require biomass to exist? There are strange varieties found in deep ice, and some in extremely dry deserts - but they're all breaking down vestigial biomass. There are very strange types somehow existing around deep ocean sulphur vents - but they're all breaking down biomass, sinking from above. There is always a proportion of ethane produced along with the methane, because there is nowhere - that we know of - that is totally shielded from solar radiation. But I grant that you're hypothesising an alien lifeform, that does not require a biosphere to function; but even so, you've still got the problem of what's happened to the atmospheric ethane on Mars. UV radiation breaks down methane into CH3 and hydrogen; the two methyl groups then recombine to form ethane. Always, in every circumstance we know of - in natural gas, in coal, in oil, in ruminant flatulence. So - where's the Martian ethane? There's only one possible plausible explanation, to my mind - ruling out the hypothesis that there are ethane-consuming creatures there too. And that is the methane must be being generated in the atmosphere, and either rapidly forming hydrated clathrates or escaping into space before any appreciable ethane can be generated. But what I don't understand is why you're so set against the meteorite source proposal? No, it doesn't. Ionisation can occur at just above absolute zero. I'm not sure what you mean by it; I meant the energy required to break the methane bonds and recombine them into ethane. This is provided by UV radiation. It would occur whatever the temperature; as it does, for example, on Saturn, at temps of below -150 C, or on Titan, where it's about -180 C. Wind, dust. Who says they've been "moved" at all? They're not witnessed: they're so labelled, by some. Like the "Canals". Sometimes in this part of the world we get in hot summers almost invisible sandstorms, as rare wind patterns allow an unusually strong Mistral to carry vast quantities of Sahara sand here, covering cars and windows. Air movements as it electrostatically settles make it virtually indistinguishable from dirt deposited or washed by rain. I asked you if you were aware of the controversy surrounding the conflicting interpretations of the weathering on the surface of The Sphinx. Evidently not. Most geologists these days would agree that the erosion patterns have been caused by water, flowing in great quantities, over long centuries, down the surface of the rock. Nearly every archaeologist and Egyptologist vehemently disagrees - on the grounds that such rainfall hasn't existed on Giza for at least seven or eight thousand years before The Sphinx was built. They assert what was until about ten years ago the accepted orthodox "scientific consensus" that the erosion patterns are those caused by sand, blowing or shifting against the rock. How do you definitively tell the difference? Very difficult. If two branches of science can reach with absolute conviction two completely contradictory conclusions from the same "witnessed" evidence, even when granted easy access to it on the Giza Plain, how are they going to decided from a few grainy photos taken in a few seconds on a planet millions of miles away? Absolutely. Methane, plus sunlight, gives you ethane. Law of chemistry. It's metabolism under sunlight. Okay - but the counter-example is?
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Post by mrsonde on Nov 7, 2012 15:10:15 GMT 1
So my conclusion was wrong totally...No methane detected up until now! But it also means that meteorites being UV dosed and releasing methane is also not the mechanism in operation. What on earth - or Mars - has led you to leap to that extraordinary conclusion?! No, I don't think so. Obviously, the methane is being produced in the atmosphere. How? By dust breaking up as it descends through it, exposing it to UV, releasing the trapped methane - just as was observed in the lab. Quite. Ergo: it's atmospheric. Not if it's not being produced on the surface there won't. There's no mystery, I think. Mars has about 1% of our atmosphere, and no appreciable magnetosphere: it's being bombarded by the solar wind, by vast quantities of protons and electrons and plasmic ions moving at relativistic velocities. The methane gets broken down far more quickly than in our comparatively protected emvironment, and either forms more complex compounds like clathrates or dissipates into space. Until about 1975 NASA strongly denied that there was any significant variation in the sunspot cycle that would lead to the Maunder, Sporer, Dalton and other minima. They insisted it necessarily couldn't be so. That's just one example where organisational collective groupthink can deny the obvious.
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