I get press releases from various astronomy sources, and the headlines are usually pretty descriptive. But when you get one that says "Mars surface probably can’t support life" you kinda have to say, well duh. It’s cold, the Sun’s UV zaps the surface, the air is 1% that of Earth’s, and what’s there is mostly CO2 and argon.
However, another press release was issued about the same topic (sometimes the universities of different team members will produce their own releases), and in it one of the astronomers says:
the intense ultraviolet exposure, the low temperatures, the lack of water and the oxidants in the soil would make it difficult for any microbe to survive on Mars.
… so I feel better.
The story itself is that electrical storms on Mars– which can be real doozies– can zap the carbon dioxide and water in the air there and create hydrogen peroxide (H2O2). That will snow down onto the surface, and any little microscopic critter there will get sterilized. When I pour hydrogen peroxide on a cut, it fizzes merrily as it oxidizes bacteria, sending them to the Great Petri Dish in the Sky. So having that toxic stuff snowing down might very well make sure that nothing grows in the martian soil (and by looking at that image above, having giant pluses and minuses flying around can’t help either). Bummer.
What’s very cool about this idea is that it might explain an old apparent paradox from Viking, the first martian lander. It had some experiments on board that looked for life. One said no, and one said maybe, in seeming contradiction. It may be that the one that said no was because it really didn’t detect any organic matter (which is what it was designed to look for), and the one that said maybe might have been because it was detecting the chemical reactivity of hydrogen peroxide, and couldn’t distinguish between that and the reactions due to life.
It’s not for sure if this is what happened or not. We’re sending more probes to Mars, including the Mars Science Lab, which is a monster compared to the two rovers there now. More sophisticated landers will yield a lot more info about the Red Planet, and hopefully answer some of these long-standing questions. If, that is, they can avoid the monster storms, solar UV, low temperatures, H2O2 snowflakes, and of course the giant pluses.
July 31st, 2006 at 5:15 pm
I don’t think of giant pluses when thinking about going to mars. Only big minuses.
July 31st, 2006 at 5:23 pm
Lightning storms on Mars? It’s interesting that you should point this out; someone just a few days ago was asking me if lightning occurs on Mars. I said I wasn’t aware if it was known to happen on Mars, but that from what I know about the Martian weather it’s highly plausible. My speculation has been vindicated.
July 31st, 2006 at 7:07 pm
Yup, gotta love the giant pluses. At first I thought it was pusses, but I missed the L… it must have been attached to my forehead, because puss couldn’t exist with the peroxide… duh… okay. Remind me not to use ‘…’ anymore!
July 31st, 2006 at 7:08 pm
Therefore under current thinking the giant minuses slightly out weigh the giant pluses on the possiblity of life on Mars!!
July 31st, 2006 at 7:48 pm
I seem to remember an old cartoon about being attacked by plus signs. . . Donald Duck in Mathmagic Land??
July 31st, 2006 at 8:05 pm
I find some great, cosmic irony in the idea that the chemical which kills off life produces reactions which mimic life, even to Viking’s imperfect senses. Fitting, somehow.
The inveterate optimist in me points out that life might have arisen when Mars was more habitable, three-odd billion years ago. (Was peroxide always raining like anti-manna from Heaven upon the Martian landscape? Not being qualified in these matters, I can only argue from ignorance, but the NASA news piece suggested to me that the H2O2 production depends upon dust storms and other present-day properties of the Martian atmosphere. Was it always so?) Supposing that the chemistry of the time was active enough to produce fairly complex molecules but not voracious enough to destroy them all again, a bit of natural selection would go a long way.
That which don’t kill ya, make ya stronger — thinking at the species level over many generations! Evolution’s motto is not “ever higher” or “progress is our most important product”, but rather “life finds a way”. . . .
July 31st, 2006 at 8:26 pm
As a microbiologist I have heard of environments that bacteria live in that make Mars look like a nice cozy intestine (cozy to a lot of bacteria). There are those that thrive in high temps with pHs approaching zero (acid mine drainage), those that thrive in, and I’m not kidding here, radioactive waste (D. radiodurans), and many other really nasty places. I think the unifying theme is water, though. Without water, biology as we know it doesn’t work. The h202 can be thwarted by high levels of catalase production (that’s what is causing the fizz: catalase is breaking h202 into oxygen and water). Cold temps are an obstacle, though. The lowest temp for bacteria is about 2C.
If there ever was microbial life on Mars, I would think it likely that it is still there. Perhaps we need to send some folks up there with a PCR rig…heh.
August 1st, 2006 at 6:54 am
“But when you get one that says “Mars surface probably can’t support life” you kinda have to say, well duh. It’s cold, the Sun’s UV zaps the surface, the air is 1% that of Earth’s, and what’s there is mostly CO2 and argon.”
Well, I’m no expert in extra terrestrial life forms, but why do we always think that life on other planets will need the same environment as we have here? That’s pretty a narrow view of the possibilities for life, isn’t it?
Mars obviously can’t support Earth life, but does that mean all life in the universe requires an Earth-like environment?
August 1st, 2006 at 9:21 am
Shawn S. says: “Without water, biology as we know it doesn’t work.”
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Um, what about the cyanobacteria Chroococcidiopsis found living in halite rock samples collected in the Atacama desert? (Astrobiology, vol 6, p415. and for the dimmer ones like me – New Scientist, vol 191, #2559 – 8/JUL/06)
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August 1st, 2006 at 11:19 am
Don’t pour hydrogen peroxide on your wounds. That fizzing you see isn’t bacteria being oxidized, it’s your tissue being oxidized.
Soap and water work fine, though you could always use some betadine if you want to be more thorough.
August 1st, 2006 at 3:21 pm
To be fair, bacteria are being oxidized, too. But yeah, what you mostly see is your skin.
writerdd, part of the question is defining “life” in a meaningful way. Any process we would recognize by our current definitions of the word rely on particular types of chemistry, in particular water. I think there are some conjectures about silicon as a replacement for carbon, but that’s pretty speculative. (I don’t know anything about cyanobacteria Chroococcidiopsis.) It is difficult to project our expectations in a way that extends beyond our current known forms that fit the criteria. We already have trouble with viruses and prions. Now you want to include something that can’t spell DNA, let alone have any?
August 1st, 2006 at 3:23 pm
I’ve never thought of Mars as a good target for life. Without a fluid (water is great, ammonia might work too, maybe ethane/methane to Titanic life) to facilitate chemical reactions it seems very unlikely.
August 1st, 2006 at 4:17 pm
So that’s where the Hydrogen Peroxide comes from…but where does the
Methane come from?
And what does this say about going to Mars, not to mention possible Colonization?
Can we say big time Terra-forming?
Probably won’t happen anytime soon.
October 27th, 2007 at 10:40 am
i think u are al nuts. how do u know there is no “life” on mars? it doesnt have to be like ours. how do u know that ALL bacteria needs water (in fact, all life). mabe it doesnt even need oxigen or anything! any way, my point is, u have to look from all point of vews, ideas, and prospects. ( im just 11 lol, i called adults nuts)