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Alex R. Blackwell

Nice post, Oliver. I like all five of your "thoughts," especially #5 ;-)

Seriously, though, as you alluded to in the other thread, the terrestrial methane production scenario outlined by Scott et al. in the PNAS paper I linked to is, I agree, fairly implausible for Mars. I linked to the paper primarily because it deals with methane production in the mantle and also because of its coincidental publication today.

Methane hydrates or clathrates, which have long been predicted to be present on Mars, especially in the polar regions, is an attractive abiogenic alternative to explain the (apparent) PFS methane signature; however, I find other features (e.g., thermodynamic stability over geologic time scale at near equatorial latitudes) problematic. Similar concerns were expressed (and published) regarding the plausibility of liquid CO2 sequestration in the martian crust as an alternative source for the erosive agent(s) that formed the martian gullies.

As hard as it is for me to accept, and I'm certainly nowhere near fully on board this option yet, the biogenic explanation for methane is still very viable. If the spatial (and temporal) correlation of the methane with H2O vapor holds up, then that, coupled with an apparent regional correlation to the dark slope streaks (thought by many to be dust avalanche scars) and the high near-surface hydrogen content detected by Mars Odyssey, then subsurface liquid water, perhaps from deep-seated aquifers below the melting isotherm, are, in my opinion, just as plausible.

One thing is clear though, as you point out. The Mars Express MARSIS and MRO SHARAD subsurface soundings of these regions are absolutely imperative to test these hypotheses.

rupert

Assuming there is methane, is there any hope of determining the isotopic ratios of the carbon - and if so, is it going to be of any interest in determining whether it's of recent biological origin? With so little atmospheric nitrogen, I don't suppose there's going to be much C14 in the first place - but what there is will find its way into methane if there are bugs pooting it out, right, and not otherwise - or am I missing something?

R

Oliver Morton

It's true that there's been speculation about clathrates on Mars since Mariner 9, though it went very quiet during the eighties, but for what it's worth almost all of that was about CO2 clathrates, not methane clathrates. And clathrates don't get you out of the problem of of sourcing the methane—they just let you shift it back in time. How far back we don't know; I agree that its unlikely that equatorial clathrates could have been stable for geological periods of time. But at some time before the clathrates you would have to have a methane source, and there's no a priori way to say whether that would have been abiogenic or not.

Oliver Morton

Rupert, I'm afraid your misgivings are correct; I'd imagine the production function for C14 on Mars must be negligible, since the amount of nitrogen is so low. C13/12 ratios may reveal something, if a good mass spec or a really great spectrometer could be brought to bear on the subject.

blairf

Hydrogen Flouride - now thats a new one!

The phase diagram here
www.airliquide.com/en/business/products/gases/gasdata/images/VaporPressureGraph/Hydrogen_Fluoride_Vapor_Pressure.GIF">http://www.airliquide.com/en/business/products/gases/gasdata/images/VaporPressureGraph/Hydrogen_Fluoride_Vapor_Pressure.GIF

seems to indicate that at 6-10 mb and 170K - 220K you are right around the boiling point of HF.
Anyone fancy swimming in a Hydroflouric acid lake?

Bruce Moomaw

Unfortunately, it's not certain that the mass spectrometer on Phoenix will even be able to detect methane at all, let alone its isotopic ratio -- the decision has not yet been reached as to whether it will include a filter to remove atomic oxygen and allow methane measurements, and even if it is I believe that this MS isn't sensitive enough to allow methane isotopic measurements. The hope there would seem to involve either the 2009 MSL, or the possibility that one of the two 2011 Mars Scouts may be the MARVEL orbiter with its supersensitive IR solar occultation specttrometer, which might be able to detect C-13 methane (although I'm not even sure about that). One thing I DO consider very probable now is that MARVEL (or an equivalent) will be one of the 2011 Scouts.

Alex R. Blackwell

Thanks, Oliver. I should have been a little clearer in stating that, indeed, it is CO2 clathrates that have been predicted for Mars, not methane clathrates. At any rate, I do agree that, under such a scenario, a plausible CH4 source(s) for that specific class of clathrates needs to be identified. That said, I have problems reconciling the apparent geology of the "methane regions," particularly Arabia Terra, with putative water and methane chemistry. At the risk of sounding repetitive, subsurface soundings (and perhaps even SAR probings of the dust and sand mantles) are imperative.

As for MARVEL, unlike Bruce I do not think it is at at all clear that this particular mission, one the four finalists in the 2007 Mars Scout competition, and which lost out to the Phoenix lander, is a "lock" for one of the two projected Mars Scouts slots in 2011. Though I would not categorically rule it out, I do not think it is certain that NASA would incorporate some sort of surface-based atmospheric investigation targeted to methane, or modify a planned-for instrument, on the 2009 Mars Science Lander (MSL). Science instrument proposals have already been submitted for MSL and, unless a proposer submitted such a capability, I doubt NASA would insist on one. Though anything is possible, I guess.

At any rate, given that one plausible explanation for a valid methane detectionis extant life, and since NASA appears, at least according to the July meeting of NASA's Solar System Exploration Subcommittee (SSES), to have selected Pathway 1: Search for Evidence of Past Life for the "Next Decade (2009-2020)" of Mars exploration, which kicks off with 2009 MSL, it is entirely conceivable that NASA will not follow up on the PFS data, at least directly. However, judging by Jim Garvin's statements to Leonard David yesterday, I think NASA (as well as the science community) is waiting to see if the PFS claims hold up before altering their fairly detailed Mars exploration strategy, though MEP is, admittedly, "discovery driven" and has some flexibility in switching to one of the three other Pathways (e.g., Pathway 3: Search for Present Life), though there will be some delay due to the required lead time in soliciting and developing instruments.

Alex R. Blackwell

Martian methane hints at oases of life
Mark Peplow
news@Nature.com
Published online: 21 September 2004; doi:10.1038/news040920-5
http://www.nature.com/news/2004/040920/full/040920-5.html

Bruce Moomaw

Well, David Grinspoon has already said (in "Slate", of all places) that he's submitted a proposal for a methane-detecting atmospheric spectrometer for MSL, although this doesn't prove it will get selected. Personally, I think methane detection is much more sensible for an orbiter than for a lander, since the main purpose is to find out where the biggest concentrations of the stuff are on the planet as a whole.

And so, while MARVEL itself is certainly not assured for the mission, I think it very likely that a trace-gas sniffer like it will be one of the 2011 Scouts. Especially since the National Academy of Sciences, in its 2002 appraisal of possible gaps in the Mars program as it then existed, called seasonal analysis of Martian atmospheric gases (including water vapor) to locate their sources and sinks one of the most important goals unmet in the program at that time, and such an orbital mapper could also do that all over the planet.

Rick L. Sterling

The Enterprise Mission published today V. Formisano's abstract from the Ischia Mars Conference. I am posting a link here in case there are some people who didn't see it under the "And No Formaldehyde Either" section. http://www.enterprisemission.com/formisanosAbstract.php

Alex R. Blackwell

From the September 23, 2004 issue of Nature:

Acid drops in the martian ocean
http://www.nature.com/nature/links/040923/040923-3.html

See also:

A picture of young Mars
http://www.nature.com/news/2004/040920/full/040920-7.html

Mars, Once Warm and Wet, Left Some Clues
http://www.space.com/scienceastronomy/mars_fizz_040922.html

Also in the September 23, 2004 issue of Nature:

Ecology: Widespread colonization by polar hypoliths
C. S. Cockell and M.D. Stokes
Nature 431, 414, (2004)
doi:10.1038/431414a
First paragraph
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v431/n7007/abs/431414a_fs.html

See also

Polar microbes get helping hand
http://www.nature.com/news/2004/040920/full/040920-9.html

New signs of life found at the Poles
http://www.eurekalert.org/pub_releases/2004-09/bas-nso092104.php

Alex R. Blackwell

Mars Express Instrument Finds Possible New Evidence in Search for Life: Water and Methane Maps Overlap
By A.J.S. Rayl
The Planetary Society
September 22, 2004
http://planetary.org/news/2004/mars-express_pfs-findings_0922.html

Oliver Morton

Bruce, Alex -- I don't know about the 2011 scout, but I'm pretty sure that more than one of the proposed instrument packages for MSL (not including Pillinger's...:-)) has methane isotope analysis as an advertised capability. It's not clear to me that that capability fits the scientifc rationale for the mission as originally conceived, which seemed to be focussed on past habitability, but the instruments are apparently on offer should they be wanted.

Also worth bearing in mind that the Discovery program might choose Mike Mumma's OOO proposal, which is an IR spectrometer as good as those at ground based facilities, but in orbit. That wouldn't be able to do delta-13C, but it would be able to detect and map methane on the disc of Mars at accuracies below 1ppb, I think.

As I mentioned a while back, the Canadians have an earth orbiting occulting spectrometer that would provide heritage for a Marvel type mission. If ESA needs something cheap to make up for the fact that exomars will surely slip from 2009, a joint program using that technology on a scout type budget might be appealing -- a way of following up what ESA will be spinning as a european discovery.

Daniele

I live in Ischia :) I didnt know about all what you are talking about :) Now i know, thx and cya all

Ischia

If you need more information about Ischia please follow the link.

Mario

Interesting article.
Regards.
Mario

Melike

I noted this back on the 24th: Then again, if the latest stuff on mehatne emmissions from the Arctic are true, then I suppose it doesn’t matter anymore, its over, for at least 5 billion plus people by 2100 (inc all of Australia). If it is true then we might as well carry on the party, burn more coal or whatever, as it is all irrelevant now, as the postive feedback mechanisms take over they will dwarf anything we can do.Then again, there is maybe one small chance, full scale nuclear war. The dust and smoke would cool the Earth for a couple of years, maybe enough to trigger off a new ice age .. maybe. At least the cooling effect would drop temperatures enough to stop the positive feedback systems and with pretty much everyone in the US, Canada, Europe, Russia all dead then man made emissions would drop enough. Best option for Australia.So to fix global warming, vote McCain. If this is the start of the positive feedback mechanisms cutting in, then we really are in big trouble. Everything seems to be happening faster than the worst case' scenarios in the late 90 s and early 2000 s predicted.I downloaded a lot of the model prediction and historical data from the IPCC a while ago and verified for myself that we seem to be on the worst case track (I am a sceptic after all).A little background that is not so well publicised. There are significant surface temperature movements from year to year from many (not entirely understood) causes. El Nino/La Nina is one for example, we are in a cool period in the Southern Hemisphere.But, more GGs still mean more energy staying on the Earth. What happens is the surface temps may drop, but that energy has to go somewhere else (ya canna defy the laws of physics captain).Basically it goes deeper underwater, when these cycles reverse then that energy comes back to the surface up again. Plus we really have no idea what impacts heating deep water will have. Perhaps it is accelerating deep water mehatne release?So what we are seeing at the moment is just heat movement, not any real cooling as some climate sceptics' claim (they give us real ones a bad name). When these cycles reverse it is not going to be very pleasant, just wait for more record temperature summers and winters soon.PS a good test to see if it is too late, all the best climate scientists disappear to places like New Zealand or the Scottish Highlands. Hang on a second, let's try. I'll just dial Jim Hanson . he's gone where???

Galin

The Australian Greens lost me over the Franklin (not that they are any better than many poilaictl' Greens). I actually remember watching the fight over it, before and after I came to Oz. Now I love the bush, I hate seeing anything beautiful killed, but we face a heart attack and they worry about a wart (actually they worry about the colour of the wart).The quote, on television no less, was the tussle over electricity usage forecasts. The Tassie hydro board had definitely overestimated Tassie usage forecasts, but I saw (might actually have been Bob Brown, long time ago) saying, even they are right, we could build a coal fired power station to meet that demand . Even back then, with no one having any idea about GGs and climate change, I would have throttled him right there and then .. yes live on television. Since then the various groups have never managed to change my opinion of them as Lenin's useful idiots' for the coal (and oil and gas) companies.Now if we dammed the Franklin and other areas and Tassie shipped electricity to Victoria so we could shut down the most polluting power stations in the world, then I'd turn the first sod of earth myself. Admittedly I'd shed a tear, but I'd still do it tommorrow.I dont think, and the various Green parties definately dont think (well have they ever), most people realise what an awful bind we, even in Australia, are now faced with. Horrible climate change with energy shortages, the ultimate lose-lose situation. Forget battery cars everyone, we dont have the power. We, at least in Victoria though nowhere else in Oz is much better, dont even have the spare power for an urgently needed massive increase in electric rail transport.You couldn't write a book about this, publishers would reject it as too fantastic. Though on the plus side we have finally answered that old question are humans smarter than yeast .

Morking

But, and I hate optimism it a disaese that should be detected at birth (ideally before birth with compulsary abortion), and treated with massive drug use (ok they might die from that but the death of an optimist is actually a really good thing).Ok it is crap, what do we do to deal with it? We work, hard. We can still, maybe just, survive.My grandfather fought the Russians, fought the Germans in WW1.Worked hard, walked 5 miles to work every day, raised children with no mother. Was an intellectual worker, a brilliant chess player. My father an engineer and a musician.Can we do no less? Of course we can. It will be tough, but we must strip away our illusions and deal with reality. There is hope, the ITER project, once we have fusion we have a chance. Our engineering ability is, frankly quite amazing. We cant turn back the seas, but we can build a lot of livable areas, even in some inhospitable areas.Our agricultural scientists can, probably and if listened to, make sure we can eat , though we are not going to be fat.There is hope.Am I any happier now, with a midlle class Oz way of life, than I was in a room and kitchen in Glasgow, surrounded with ideas, books and music? Actually not, there was no money, but a lot more fun.

Lahlou

If you really give a crap, stop byniug meat, and dig up your fromt lawn to plant a vegetable garden. .No, we have to develop a taste for kangaroo meat.Reduced numbers of hard hooved animals on dry fragile soils is a good thing , long rotation spelling /short rotataion grazing if they stay , appropriate carbon charges which should be paid by the consumer who pursues their choice of red meat..Interestingly there are already discussions on other site about the husbandry needed to manage kangaroos tail docking while in the pouch for instance, castration of the males to deter aggressive bullying and fighting, new cradles being necessary for handling..Oh and a couple of points Laura digging up lawns encourages C02 release minimum tillage is the way to go . And giving up meat eating pets would also mean the demand for red meats would be greatly reduced rabbits make much nicer pets and once they get too old they taste good too!

Gina

In 2007 we lost the whole .7 deg C that it took 30 years to gain. If you study the real science, or even glnace at it in a cursory fashion, you will note that this sentence is completely incorrect.2007 was the seventh warmest year on record since 1850 with temperatures 0.4baC above average. The reason why it was slightly cooler than some years preceding it is well known the cooling effect of the La Nina as opposed to the warming El Nino that affected 1998 in particular.The sunspot cycle's influence has been observed over many cycles and contributes 0.1 0.2baC, so even if the sunspot cycle stays low indefinitiely, that's not going to provide much cooling.So if La Nina was cooling, the sunspot cycle was cooling, why was 2007 still the seventh warmest year on record?

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