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Microbes grow in Mars conditions
Iguana writes "A methane-making, oxygen-hating microbe is able to thrive in Mars-like laboratory conditions, according to a researcher who says the experiment raises fresh hope about the possibility of life on the Red Planet. Check the whole story on MSNBC " "And kids, that the story of how hemos grew cmdrtaco". Oh...er.
Anaerobic organisms have the ability to live without oxygen. Many (perhaps most or all) of them cannot survive in the presence of oxygen. Byproducts of anaerobic metabolism include ethanol and lactic acid. Anaerobic bacteria are not so uncommon. They live in the guts of humans and many other organisms. They also live in many extreme environments such as hot springs, ocean vents, etc.
Photosynthetic organisms (commons ones, anyway) produce oxygen as a byproduct. They use light energy directly to make their own food molecules. Early photosynthetic organisms were probably also anaerobic, but photosynthetic and anaerobic are distinct concepts.
Possible evolution:
1. Anaerobic organisms live and obtain their energy from molecules in their environments.
2. Some anaerobic organisms gain the ability to photosynthesize, being able to use simpler molecules than their predecessors along with light energy from the sun while producing oxygen as a byproduct.
3. Oxygen levels increase due to the prosperity of photosynthetic organisms.
4. Anaerobic organisms die in large numbers as the atmospheric oxygen level rises.
5. New, more efficient aerobic organisms appear and further the decline of anaerobic organisms.
Although I cannot currently access my password to log in, I am
Yet Another Coward
You know, with all the emphasis given to landing stuff on Mars, I'm surprised that I haven't heard any talk of NASA sending these microbes (as well as a variety of life forms that don't qualify as animal -- wouldn't want to enrage the environmentalists, now would we?) in a controlled experiment to the Martian surface. We do our darndest to prove that life could possibly exist on Mars here on Earth, but the best Martian simulation is Mars itself. If we can send a robotic probe to the Martian surface and turn cartwheels in the dust all day, we can certainly set up rudimentary experiments that determine what kinds of lifeforms truly do live in such a harsh environment.
I hope someone from NASA reads Slashdot and can comment on this. Hopefully, an engineer inside NASA's organization has already thought of this. I can't see why it would be that difficult.
Mars is also 1.637 times farther away from the sun, so it gets only 0.373 times the solar radiation as Terra here gets. Ultra violet solar radiation is probably still quite a big problem on Mars. And even though Mars is a lot farther away, solar winds might also provide a big problem. Due to its proximity to the Asteroid Belt it's also more likely to be hit by a big piece of space junk. Actually, Antarctica and the Sahara are hundreds of times more hospitable to human life than Mars.
But then again, in the place that is the most inhospitable to human life here on Earth, in the depths of the oceans, there is life, completely independent from the sun. Actually I think the chance of finding life on Europa are larger than the chance of finding life on Mars. Mars' climate is unlike that anywhere on earth. Below Europa's icey surface are liquid oceans, melted by its volcanos; an environment quite similar to the depths of the Earth's oceans; an environment quite similar to the environment many scientists believe spawned the first life on Earth.
)O(
the Gods have a sense of humor,
Never underestimate the power of stupidity
To err is human, to moo bovine
Actually, he probably got this idea from reading the works of Richard C. Hoagland, who was the first to come forth with credible evidence of liquid water beneath the surface of Europa.
The heat that could keep the system going would, indeed, be caused by vulcanism. However, it is doubtful that that volcanic activity will ever cease. Consider that Europa is probably about the same age as the Earth, and is at least hypothetically volcanically active. This volcanic activity would be caused by the gravitational forces of Jupiter and the other moons, and isn't likely to change (unless something rather drastic happens in the vicinity of Jupiter).
Io, another of Jupiter's moons, is visibly volcanically active (probably the most active body in the whole solar system). It is and will remain very hot because of the gravitation of Jupiter.
So, if Europa is currently volcanically active (a likely hypothesis, given the gravitational oomph of Jupiter), and has a big bunch of water ice (we believe we've observed this), and has liquid water beneath an icy crust (another likely hypothesis, given the heat that must be at the core of that little moon), then assuming that some kind of life could have organized itself there, and could have evolved to the point where it can survive in the water (which must be quite toxic, at least by our standards, by now, though what is garbage to us might well be rich nutrition to some little beasties on Europa), then it's a good possibility that life exists there to this day.
--Corey
Not only will they not deserve liberty or safety, Mr. Franklin, they will be DENIED both!
Why do they have to get involved in everything? Geez, isn't it enough that they dominate down here on earth? Now they have to spread to Mars!
Oh, wait.... Microbes.... I thought it said "Microsoft".
Never mind.
Save the whales. Feed the hungry. Free the mallocs.
Although I'm no expert on the subject and all real questions should be asked of Dr. Kral himself, I do have a passing familiarity with his experiments after certain lectures he gave in my micro class (I attend the University of Arkansas and had him for class this past year).
He is really not trying to say anything special about this experiment; his happens to be a field which excites the imagination and draws popular attention. As such, I think that many of the quotes he has are the result of a request to speculate...
Anyway, his experiment was simply to grow microorganisms in a fairly hostile environment which approximates many of the things that we know about current conditions on Mars. He used volcanic ash which is believed to resemble Martian soil. No temperature or pressure differences were attempted in the first run because little is known about below Mars below the surface. Indeed, the surface is too cold for liquid water (apparently around -200C) and higher temperatures must be assumed if life (as we currently understand it) currently exists on Mars. There are plans for a range of growth conditions which include harsher temperatures and pressures (as far as I know, no one has been able to grow microbes in the experimental conditions, let alone less hospitable ones).
As far as radiation goes, both ionizing and non-ionizing forms are incident on the surface of Mars. However, at subsurface depths there is little reason to think that the intensities will remain the same, especially for non-ionizing (such as UV) forms. Since this is the environment which is to be modeled, radiation was ignored.
Questions about nitrogen appear to stem from a misunderstanding, perhaps, of the metabolism of Archaebacteria. These bacteria are believed by many to be ancestral to the more accessible bacteria which abound on earth and in textbooks. Methanogens, from a very basic understanding that I have, can use a variety of molecules to provide the reducing power necessary to produce biologically accessible forms of energy and, as a result, biologically useful molecules. I know
that NO3 is used but am less sure about pure nitrogen. I am not sure that the researchers themselves know the specific nitrogen source the microbes utilized, but it is believed that the nitrogen content of the experimental medium was ~1%, less than the 3% believed to be present in the Martian atmosphere. In any event, the microbes do not tolerate oxygen (it forms radicals which the cell cannot handle) and it is thought that, esp. given the low level of atmospheric oxygen, subsurface levels of O2 would be conducive to cell growth.
Finally, as to previous proof of life on Mars (esp. the ALH001 meteorite), recent research has cast doubt on Zare, et. al's hypotheses. In fact, this past year Dr. Kral coauthored a paper which suggested that similar chemical patterns could be identified on rocks taken from the moon. Because the moon is such an unlikely candidate for life, the meteorite evidence shouldn't stand on its own as proof of life anywhere.
This all just goes to say that no one will really know anything for certain about life on Mars until some redneck terraformer comes down with a cold...
Sources for this post come from the university press release:
http://PIGTRAIL.UARK.EDU/NEWS/june99/ mars_life.html
Sears D. W. G. and Kral T. A. (1998) Martian "microfossils" in lunar meteorites? Meteoritics and Planetary Science 33, 791-794,
and correspondence with members of the research group. All information presented herein represent the (somewhat poor) understanding of an
unrelated party (me!) and do not represent the actual researchers' beliefs or opinions.
Invicta{HOG}
You're absolutely correct. The article doesn't explicitly mention whether radiation and other non-atmospheric conditions were taken into account. Hopefully it just didn't make it into the layman's terms version of the research summary.
/. post is somewhat misleading ("...raises the possibility of life on the Red Planet"). The article mentions nothing of actual life on Mars, past or present. The main focus, in fact, seems to be transplanting this earth-made organism _to_ Mars in order to create methane and change the climate somewhat (to facilitate human colonization).
Another important thing to think about (and I hope that people don't draw this conclusion) is that just because we've found something that could _conceiveably_ survive on Mars, it doesn't mean that it or anything like it ever did. I only mention this because the header of the
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