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Posted by: Decepticon Jan 8 2007, 08:12 PM

I'm surprised no one posted this yet.

http://edition.cnn.com/2007/TECH/01/07/mars.life.ap/index.html

Posted by: um3k Jan 8 2007, 08:16 PM

I was about to...but you beat me to it by about two minutes.

Posted by: AlexBlackwell Jan 8 2007, 08:24 PM

See also this http://www.ccnmag.com/news.php?id=4702 and this http://arxiv.org/abs/physics/10093.

Posted by: AlexBlackwell Jan 8 2007, 08:40 PM

This is the http://www.abstractsonline.com/viewer/viewAbstract.asp?CKey={D91F5D8E-C708-4ACD-92BE-04BCA261C48B}&MKey={54CA33F4-2503-46C6-A27F-8E02C1C98DC0}&AKey={AAF9AABA-B0FF-4235-8AEC-74F22FC76386}&SKey={9ADFD7F8-71D1-4CCD-8763-BACAF719EE4A} from the ongoing AAS/AAPT Joint Meeting.

I guess no one http://www.unmannedspaceflight.com/index.php?s=&showtopic=3598&view=findpost&p=78435 them, huh?

Posted by: tedstryk Jan 8 2007, 09:52 PM

I tend to ignore abstracts with regard to life-detection and Viking. It may turn out that signs were in the data that we missed. Maybe not. But I believe it will take a new mission to find out anything reasonably conclusive.

Posted by: tuvas Jan 8 2007, 10:25 PM

I think that title is a bit overdramatic, but, well, I guess it happens with the media sometimes... Still, there isn't a way to tell about the Viking lander life results, so, well, there isn't much point for the general public to be arguing the results...

Posted by: edstrick Jan 9 2007, 08:16 AM

given the reactivity of hydrogen peroxide, I'm rather skeptical on how it might accumulate in large enough amounts to serve as a biological solvent. I'll have to read the paper, but.... I'm skeptical. It's an interesting speculation, maybe even a hypothesis, I wouldn't call it a theory by a long shot.

Posted by: Stephen Jan 9 2007, 09:56 AM

Actually an anaerobic organism would probably have something broadly similar to say about the the reactivity of plain old O2 and the resultant unlikelihood of anything biological being able to survive in an environment flooded with the nasty stuff!

======
Stephen

Posted by: TheChemist Jan 9 2007, 10:59 AM

Schulze-Makuch I can understand, it is his field. But Houtkooper ?
Look at his last three publications :


Hinterberger T, Houtkooper JM, Kotchoubey B
http://wos.ekt.gr/CIW.cgi?254963_52511335_254963-0&Func=Abstract&doc=3/1
J PARAPSYCHOL 69 (1): 26-27 SPR 2005

Houtkooper JM
http://wos.ekt.gr/CIW.cgi?254963_52511335_254963-0&Func=Abstract&doc=3/2
J PARAPSYCHOL 69 (1): 27-28 SPR 2005

De Graaf TK, Houtkooper JM
http://wos.ekt.gr/CIW.cgi?254963_52511335_254963-0&Func=Abstract&doc=3/3
J PARAPSYCHOL 68 (1): 93-127 SPR 2004

Yes, it is the Journal of Parapsychology
What does parapsychology have to do with mars microbes and their biochemistry ? Beats me ....


P.S. Links will only work for Web of Science subscribers, sorry
I'm getting rusty ... session expired and links do not work even for me 5 minutes later, duh !

Posted by: marsbug Jan 9 2007, 02:06 PM

Hello everybody, I've been a long time lurker at UMSF, mainly because I didn't feel I had much to contribute, but I've finally run across something thats made me curious enough to step into the light. Space.com and Astrobiology.com are both running stories on how the viking life detection experiments are consistent with the presence of microbes with hydrogen peroxide as their internal fluid instead of water. I've got no background in chemistry but I have first hand experiance of how unpleasant hydrogen peroxide is (I once spilt some on myself and I stil have a faint scar on my hand) so I was wondering if someone could give my the short words and big pictures explanation of how such a creature would work? If this is already being discussed elsewhere many apologies.

Posted by: MarkL Jan 9 2007, 02:43 PM

Its a fanciful grab for attention, and at bottom is unfounded speculation -- give them credit for a good PR job but it still is hollow science. Put it on ignore.

Posted by: AlexBlackwell Jan 10 2007, 06:56 PM

Here's a paper in press with Earth and Planetary Science Letters that is slightly related:

Production of hydrogen peroxide in Martian and lunar soils
Earth Planet. Sci. Lett., In Press, Corrected Proof, Available online 10 January 2007
Joel A. Hurowitz, Nicholas J. Tosca, Scott M. McLennan and Martin A.A. Schoonen
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V61-4MSR8V0-5&_user=1349829&_handle=C-WA-A-DW-DW-MsSAYVA-UUW-U-U-DW-U-U-AADAUWEAAW-AAZYZUEEAW-WUVVEEZAA-DW-U&_fmt=summary&_coverDate=01%2F10%2F2007&_rdoc=6&_orig=browse&_srch=%23toc%235801%239999%23999999999%2399999!&_cdi=5801&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=1349829&md5=79d3828ab7e780a68f1ca2f610331dd4

Posted by: dvandorn Jan 10 2007, 08:09 PM

What strikes me as funny in this particular article is that the Viking life-detection experiments were *always* designed to sterilize their samples at some point during the process. In other words, the experiments were *designed* to kill Martian life, if it existed. It would have been difficult to determine if there was life or not had they not run the same tests on sterilized vs. non-sterilized samples, and IIRC at least one of the experiments ran its gas-release tests and *then* heat-sterilized its samples before running further tests on them.

At least the astronomer who talked with Keith Olbermann got all of that straightened out, so anyone who watched Countdown that night got the story straight...

-the other Doug

Posted by: Alex Chapman Jan 11 2007, 09:15 AM

I am another long term lurker and I just thought I would and my view to this debate. First of all micro-organisms only survive and replicate in conditions similar to those they have evolved in. If you put some Staphylococcus aureus, the bacteria that causes pimples, next to a deep sea hydrothermal vent its not going to do well and the same is true if an extremeophile from that vent was placed on your skin. In fact, we only really have a good understanding of micro-organisms that thrive in conditions similar to the ones produced by our own bodies. We can’t even grow most of the naturally occurring soil bacteria in a lab, nutrient or blood agar at 37C just isn’t what most micro-organisms have evolved to metabolise.

So yes the Viking experiments were fundamentally flawed and were really looking for dormant organisms that would thrive in a 1970’s lab. Martian Life if it exists will thrive in Martian conditions and that is really how it should be studied.

How do you look for something that you don’t know is there and you don’t know what its like? That’s anyone’s guess and we are just going to have to keep sending in-situ experiment packages looking at different regions of mars and attacking the life question from different angles till we get lucky. To be honest the best hope we have is for a large scale series of sample return missions or else get 50 microbiologists on the surface for 5 years. Trying to look at old data that used fundamentally flawed experiments just won’t give an answer.

Only when we see life and see it growing and multiplying and metabolising right in front of us will we conclusively know we have found Martian Life.

As for the hydrogen peroxide question you might as well theorise that life on Mars uses propane or butane as a solvent but that’s all it is a theory, well more like wild speculation and is pretty much pointless. We need to look with open minds and see what not guess what’s there is there and try to prove we are right.

Posted by: edstrick Jan 11 2007, 12:53 PM

"... the Viking experiments were fundamentally flawed and were really looking for dormant organisms that would thrive in a 1970’s lab...."

Yes and more accurately no.
Viking had 1 biology instrument containing 3 independent experiments. In addition, it carried out a sensative <though not perfect> search for organics in the soil and atmosphere with a gas-chromatograph/mass spectrometer, and looked for visual signs of organisms (from Thoats and Green Martians to martian lichens and microbial mats) with the cameras.

The biology experiment everyone remembers was Gil Levin's Labled Release experiment, that added radioactive carbon labled "soup" to soils and measured the evolution of radioactive gas into the chamber above the soils. Generally adding soup to fresh soils produced a prompt evolution of gas from the soup that tapered off. Adding more soup didn't do much. Sterilized soils produced essentially no reaction. Soils stored onboard the lander for weeks showed little reaction. One sample run gave data that fluctuated "weirdly" and doesn't make sense in terms of biology, chemical reaction or instrument malfunction. Levin interprets the result as due to life. Others identify it as a one-shot reaction that reacted with most of ONE ingredient in the labled soup (some format ?) and progressively ran to completion. Levin minimizes the point that there was no growth-like reaction... slow release, then fast as organisms grow, then slow as they use up food.

A second experiment, the "gas exchange" experiment put the soil in a cell and added moisture, first not wetting the soil, but simply as humidity, then adding more to wet the soil. There were NO NUTRIENTS in the liquid. It periodically measured gas composition in the air above the soil with a small gas chromatograph. Oxygen and CO2 levels fluctuated during the runs: there was a prompt release of oxygen when the soil was humidified, then slow variations in O2 and CO2 levels with time. This is the main source of evidence of peroxides in the soil. I think heat sterilization of the soil tended to sharply reduce the O2 release.

The third experiment was "pyrolitic release" which simply assumed organisms in soil could take in CO2 from the atmosphere and turn it into organisms with the aid of light. They put radioactive CO2 <and CO?> in the cell and turned a sun-lamp on and waited. Then they flushed the cell, roasted it to cook any organics to pieces, and measured released radioactive carbon. There were usually small positive responses that were killed by heat sterilizing the soil. This was the most lifelike response seen in any of the experiments but it was weak, and the only data is the without and with sterilization numbers for matched samples. Very low data output experiment.

So the 3 experiments ran from very Earth like to pretty Mars like except for above-freezing temperatures in the experiment package. Given the state of knowledge about Mars about 1970 when the instruments were picked, they did a damn fine job of trying a range of possibilities. We really DID learn about Mars soil from the experiments, but most useful data is from the gas exchange experiment. We really don't know WHAT the pyrolytic release and labled release experiments are telling us, despite Levin and associates claims to the contrary. There are models that are claimed to explain most of it with metal peroxides and stuff in the soils, but Levin disagrees and I haven't taken the 2 dedicated weeks to read and re-read and exhaustively dissect the entire literature on the controversy to be able to report a relatively unbiassed opinion on what we know, suspect, guess,and don't know.

Phoenix is going to carry out a battery of chemical tests on soils that are going to push a long way toward understanding their peculiar chemistry, but in all reality, a 1 gram sample return of soil would undoubtly have the same *BOING* data-shock surprises as they're getting from the Stardust samples.

Posted by: Bob Shaw Jan 11 2007, 12:56 PM

Early designs for experimental devices to investigate Martian life had great names, like 'Gulliver'. Came the 70s and we just got boring abelled release experiments.

In view of the current extreme range of uncertainty and confusion, may I make a modest proposal: we should press for any new life detection experiment to reflect our inability to sort out the noise from the data (sic) and should name the next device after a true cultural icon of our time!

In short, gentlemen and ladies (damn few apart from Emily!), I give you...

...the Rumsfeld Experiment!


Bob Shaw

Posted by: dvandorn Jan 11 2007, 07:53 PM

Bob, here I thought you were going to suggest eating Martian babies!

Of course, had you done so, you would have deserved a good Swift kick in the pants...

-the other Doug

Posted by: Bob Shaw Jan 11 2007, 09:18 PM

oDoug:

The reference was *entirely* deliberate!


Bob Shaw