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Life on Mars? Why Not?
Guillaume Filion writes "IEEE spectrum has an interesting article about a new probe sent to Mars searching for life: 'Recent missions to Mars have focused on the search for water, past or present, as a surrogate for life itself. But now a British-led team is working to renew the search for life directly, fueled by doubts about the equipment that prompted NASA to declare Mars a dead world some 26 years ago.'"
When a team is "fueled by doubts," I can only be pessimistic and assume a negative outcome. I'd much rather be fueled by something a little more positive.
The anti-salmon
There may be things that reproduce and show signs of life on Mars, but we'll spend a lot of time trying to cram the stuff on Mars into the categories we have on Earth.
Hint: Chances are, no matter what we do, we're never gonna see a green spectral line or test for clorophyll.
Instead, we need to examine soil for the most basic types of life we know of... creatures or cells similar to viruses, bacteria, and amoeba.
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Why do we assume that life on other worlds would have the same requirements as life on earth?
We were either created for this world or evolved into what we are by it. Doesn't it make sense that life on other worlds would be fit for theirs in the same way?
Why is water so damn important? Couldn't life be based upon a different liquid than water? A different solid than carbon?
You can't judge a book by the way it wears its hair.
Or at least not as we know it. Here on earth, life is so all encompassing that there isn't a place we have gone that we haven't found evidence of life. It doesn't matter whether you go to the deepest ocean, or the hottest volcano, there are either living things, or obviously formerly living things. So either life on mars has not reached any sort of detectable level, or died out long ago.
OTOH, personally I believe that life was created on earth and not elsewhere, but I believe that it is our responsibility to explore to build and to discover.
Food not Bombs is a nice platitude but it breaks down when you notice that the Bombees are usually well fed
If life had existed in the presumable oceans on Mars back in the day, then it is possible that there is life in the water vapor in the atmosphere (just as there is life in our atmosphere). Of course, I'm not sure that there is much (any?) water in the atmosphere on Mars. Furthermore, Mars didn't overheat, and there is not as much water in the polar ice caps as we had expected. To me this indicated that most of the water must have gone down below the surface; it could have easily brought microbial life down with it, as Earth has much microbial life beneath the earth.
Umm, I believe we have already proven that life exists in the void of space. IIRC, wasn't MIR 'infected' (yes, it was a bad case, from what I heard) with a type of mold that wasn't terrestrial to our planet?
Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
This isn't how science works. Its sort of like the free market, but instead of money being the reward, its recognition. Without it, there would be little motive for PhD's to study anything.
I mean, if rocks from Mars made it to the earth, then for sure some rocks made the trip the other way. Bacteria would probably survive something like that. They wouldn't necesarily grow, but still there would be life.
If we find evidence of past life on Mars it will mean that in one out of two known cases life on a planet has gone (pretty much, at least) extinct. I would hope that the Gaia hypothesis is right, and that a living planet's biosphere really is self-regulating and not succeptable to such catastophic failure.
It certainly woulnd't the end of the Gaia Hypothesis-it might be that loss of atmosphere on a low G world is one of the few things life can't prevent-but it would certainly be a point against it.
This sig wasn't worth reading, was it.
Life on Mars? Why Not?
Well what if there is life on Mars from Earth? Lets suppose the probes sent to Mars had living cells on them when leaving this planet. They would almost have to had contained living cells since Earth is full of tiny single cell organisms; some of which do not use oxygen. Would it be possible for us to have caused contamination of Mars and there actually be living cells on Mars from ~30 years ago?
James Lovelock, one of the true ninja hacker lords, has suggested that of all planets in the solar system, only Earth looks like it harbors life, because only it has an atmosphere that is out of chemical equilibrium.
Lovelock, a atmospheric chemist and inventor who made his fortune on the ion-capture gas chromatography detector, is the author of the so-called Gaia Hypothesis. Romantic name aside, it's the idea that the presence of life alters a planet's environment to be more favorable to life. (The idea and name have been appropriated by eco-mystics who take it to mean that there actually is some sort of earth deity, but that's emphatically not what Lovelock is saying.)
On our planet, many atmospheric gases are grossly out of equilibrium. For instance, although the atmosphere is about one-fifth oxygen, there are detectable traces of methane, mostly from termites and "the farts of ruminants". If life were not continually renewing the methane, it would combine with the oxygen, and disappear in a few hours.
Of course, the presence of oxygen itself is an anomaly. It is so reactive that if it were not renewed by photosynthesis, it would bind with the copious free carbon lying about.
Lovelock gives many other examples in his excellent book, Gaia, A New Look at Life on Earth. (He also mentions that the presence of fluorocarbons, like Freon, in the atmosphere is a clear sign, not just of life, but of intelligent life. Since you can determine atmospheric composition by spectrometry through a telescope, this gives a way to detect civilization if only you can image a planet hosting it.)
There's a clue in the simple appearance of the planets from space: compare the complex and constantly-changing appearance of the Earth's patchy clouds, liquid-water ocean, and of course its wildly varying landmasses (including snowcaps, yellow deserts, chlorphyll-green jungles, and seasonal temperate forests and grasslands), with the dead, relatively static appearance of any other planet in the system. Our nervous systems have life-detection circuits built in; honestly now, do you see any when you look at Mars?
The key is that Earth is alone in all the solar system in having a disequilibrium chemistry. This doesn't mean that there wasn't life elsewhere at one time; it may not even mean that there aren't small, isolated outposts that support some life, but not enough to control the entire planet. Certainly, life on Earth had to start that way.
Nevertheless, although there may indeed have been a time, early in its history, when life florished on Mars, it seems dead now.
In the wrong hands, sanity is a dangerous weapon.
That's not to say that life cannot exist without water, but it certainly makes life much more plausible.
You're not giving water enough credit. Basically, the important thing is to qualify what is life: life is the creation of complex systems that can adapt and increase in complexity over time. That's a decent definition of life - it excludes fire, for one, which is always a difficult one. In order to satisfy that definition, you need a framework which allows you tons of complexity, which is what water gives you. Gotta love water.
Water is the simplest dipole that can form. You can't make a dipole out of HX, and if you want H2X, water's the easiest choice. Is it really any amazing wonder that nature, needing a dipole (which allows for complex arrangements), chose the simplest one? Hmm. Bout as surprising that the elements used in life happen to be the most common in the universe (barring helium).
-Maybe- ammonia. Maybe.
Life -needs- a dipole. Life also needs a 'backbone' - a framework. Carbon's your only choice for that.
A carbon-silicon combo might work.
Why in the world would life EVER use silicon, when carbon is so much more abundant than it, and will be no matter where you go in the universe, and carbon doesn't need silicon? All it does is weaken the structure.
Carbon's a given - it's the only one that'd work.
Eh? You're giving water too much credit, now. The stuff on which all our beloved complex molecules depend is carbon--water is just a useful solvent. In and of itself, water creates structures like ice crystals or cages (e.g. clathrates). Interesting for a number of reasons, sometimes very pretty, but not particularly 'complex' in the sense that you mean. For us, water is a very nice solvent because it is polar (you can dissolve ions in it) and amphoteric (it can act as a proton donor or acceptor depending on ambient conditions). Liquid ammonia (NH_3) would do almost as well, in principle.
Water is the simplest dipole that can form. You can't make a dipole out of HX, and if you want H2X, water's the easiest choice.
I'm not quite sure what you're getting at here. HX--where X is anything but hydrogen--is always a dipole.
~Idarubicin
A couple things against Lovelock's ideas. Didn't the Earth have a reducing atmosphere for billions of years until "blue-green algae" (cyanobacteria) got a toehold? Don't know about Antartica, but the extremophile organisms at thermal ocean vents and in hot springs don't seem to be regressed evolution from more normal bacteria but seem to be a more primitive, ancient form of life -- the hot springs are perhaps closer to the early Earth and may have been where life started. Was life always in control of its environment from its most primitive stages, or did that kick in with the oxygen revolution?
Terra Forming is Star Drek sci-fi. Obviously there will be no rapidly evolving "life" as we understand it on the present Mars.
If there are single celled organisms or even clustering goo, it will prove to be of little scientific interest. Even the genetics of these oganisms will be useless: UNLESS we find that these organisms contain code that closely resembles similar organisms on Earth!
Then the implications are that just maybe we are the Martians.
Mars exploration is crucial to our understanding of natural science. The benefit is employement for large numbers of brilliant, dedicated and hard working humans in fields other than defence!
JFK was right and not a bleading heart liberal.
To wean us of defence we need great scientific and engineering projects that span boarders.
Now that communism is creaking and China is slowly seeing the light, what is wrong with international space exploration. I believe common goals for humankind are a necessity if we are to survive. Even if these goals prove to be wrong they are still better than rabid scientific militarism.
Lets smoke the pipe of peace for real!
The alternative is big clouds of radioactive smoke.
OH THE SHAME I fell off the wagon and use sigs again!