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I'm surprised nobody thought of doing this analyses before; researchers recently noticed a periodicity in mars impacts(I wonder how much of this periodicity matches the periodicity on earth which would be in agreement with the Nemesis theoy that a companion star disturnes the comet clouds every 26 million years which is responsible for the periodic mass extinctions here on earth). Anyway's, when they looked into the consequences for mars, they've discovered how to account for mars' canals without mars ever having long enough warm period for life to develop much at all. Seems mars was alway's to cold for life to develop.
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Hi oker56!
I have doubts about how easy it is to be certain of dating impact events on Mars.
I remember when the lunar craters were being considered. Observations from a distance gave scientists a pretty good idea of the order of events as far as cratering was concerned. But absolute dating had to wait until the Apollo astronauts brought home rocks from carefully catalogued sites on the Moon.
Even so, I understand that there are still many unanswered questions and lunar geologists would dearly love to go back to Luna for more samples from different areas.
The topography of Mars is even more complex than that of the Moon, having been subjected to episodic water erosion, including possible sedimentation from persistent standing bodies of water, in addition to prolonged aeolian weathering. Neither of these factors applies to our satellite. Also, Mars is closer to the asteroid belt and the gravitational field of Jupiter, which may have complicated the history of cratering - making extrapolations from the Earth-Moon system unreliable.
In the absence of an accurate catalogue of dated rocks, I don't see how anyone can be certain of the order of events in Martian geological history.
While the new hypothesis you mention may turn out to be quite right that some of the flooding was triggered by impact breeching of aquifers etc., my money is on the notion that the Martian climate was actually balmy for longish periods. There's just too much evidence for surface water, which must have been stable in liquid form for long enough to form large lakes, if not the fabled Oceanus Borealis itself!
The remarkable smoothness of the northern plains (the smoothest large-scale surface in the solar system) is so reminiscent of the sediment-smoothed abyssal plains of Earth's deep oceans, that I have to say I lean towards believing in a former Martian ocean!
I have to admit, I could be as wrong as wrong can be! I'm just as much a hostage to future discoveries as anyone else.
Furthermore, I would be lying if I pretended that what I'm preaching isn't also what I want to be true!!
We'll all just have to wait and see, I guess!
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
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Hi Shaun. I think your cute
Well, if there's life on Mars, or was, it was microbes. Right?? Does anybody here think higher life than that was ever on Mars? I don't.
happy holidays :0)
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Even though I enthusiastically believed at one time that life on Mars was very likely I've begun to think otherwise. Even though I agree with Shaun that it seems presumptuous of us to think we can accurately date those crater basins I still think there's a lot of possibility that the evidence of liquid water as seen on Mars was due to the melting of ice from asteroid impacts and this water didn't exist long enough for any kind of life to form. Of course I'm hoping though that we prove those theories wrong and find that large oceans did exist long enough on Mars for life to develop. Come to think of it those theories aren't mutually exclusive. They could both be true.
To achieve the impossible you must attempt the absurd
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The scientific way would be to get to mars and do some exploring, but in the meantime . . . .
The smooth side of mars could be due to the fact that the oceans of water produced by asteriod impacts was located where the smooth areas are and flowed through the carved out areas. The reason for that I don't know.
Anyway's, the idea that the carved out regions of mars due to asteroid impact's causing massive water works with James Lovelocks theory that once life takes hold, it maintains the conditions for life. This clearly has not happened on mars. This reason is why I like this latest idea.
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perhaps life formed on mars, but didnt last long enough to change its environment. the processes required to change a planet sufficiently, to terraform a planet, are very complex, and immature microbes are not likely to be able to combat an ice age.
what if an asteroid hit mars while life was forming, ending the period of life, cutting it off as a comet cut off the dinosaurs?
im no expert, but this seems just as likely to me.
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what if an asteroid hit mars while life was forming, ending the period of life, cutting it off as a comet cut off the dinosaurs?
Considering Mars's proximity to the asteroid belt I think it's possible that asteroid impacts could have wiped out life on Mars before it got a good start. If it coudl happen to Earth it could definately happen to Mars even though I'm thinking microbes would be a lot more resistant to asteroid impacts than higher life but they aren't invulnerable either. Considering Mars's small size that would make it all the more vulnerable to asteroid impacts.
To achieve the impossible you must attempt the absurd
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I must say that the Gaia effect doesn't take full effect untill the rocks absorb all the oxygen which then makes the oxygen accumulate in the atmosphere. At that time, life went through the oxygen haulicaust. Around that time, microbes then figured out how to use oxygen. This was around two billion years of earth's history, so yes, the microbes may not have had enough time to take hold of the planet's atmosphere.
What about microbes forming in short time periods? Well, I do know of Stuart Kauffman's complexity theory which say's that when the number of molecular species equal's half the feedback loops of a chemical network, they spontaineously assemble into a lifeform. The issue here is that the planet needs to stay in a state of energy flux for the diversity of molecules to develop. Would the amount of time mar's is overflowing with water be enough time for molecular diversity to accumulate? I'm tempted to say yes, but with all the energetic violence and not enough time to adapt to it all, most microbes that develop would then be destroyed. Mar's surface is very reactive, meaning it is very simple chemistry.
I would also like to point out that the evidences of life suggest life arose in underwater heat vents first. These heat vent's can combine metal's in the diversity of molecules necessary for life to form; mar's ocean's never lasted so long.
Maybe someday when we develop sophisticated molecular nanotechnology, we can do a molecular scale exploration of mars and find one lone fossil microbe that survived the billion's of years of violence.
I'm going for europa to reveal the first microbes.
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So far in this thread, everybody is assuming that for life to have existed (or to exist still) on Mars, it has to have developed on Mars.
This is very likely to be untrue because of impact transfer of viable micro-organisms between Earth and Mars.
We're reasonably sure that life on Earth developed about 3.8 billion years ago. In fact, it may well have developed more than once prior to that time, but was extinguished by massive impact events which melted much of the crust. (Some people believe it may have come within an ace of extinction several times after 3.8 billion years ago, too! )
So, from about 3.8 billion years ago, Earth has been regularly inoculating Mars with bacteria, perhaps every few thousand years on average.
On many of those occasions, Mars was probably going through a warm wet episode - whether asteroid or volcano induced doesn't matter .
The point is that our space-faring bacteria would frequently have encountered conditions conducive to life and would have gained a foothold. As anyone in charge of sterile procedures in a hospital Operating Room will tell you, eliminating micro-organisms from anything or from anywhere is very hard work! Once they've moved in, evicting those little ba****ds is next-door to impossible!!
No. For what it's worth, my opinion is entirely unaffected by this latest attempt to unravel the mysteries of Martian history.
I'm as convinced as ever that we'll find thriving and diverse populations of Earth-type bacteria in all sorts of places on Mars. If life has been there for as long as I think it must have been, I wouldn't even rule out the possibility that life forms more complex than bacteria may have evolved.
But, Nida, that's obviously just pure speculation on my part and single-celled organisms might be as far as Mars ever got on the evolutionary ladder. And even then, that might only have been a gift from Earth!
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
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Despite our agreement that we must go to mars and explore it to confirm or deny theories, your idea has one failing; the mars microbes would not be martians! They would be earthlings!
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earthlings might not be earthlings. the major theory ive heard about life's origin on earth stems from a comet (or comets) that brought the organic matter needed for life to earth.
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You mean: "We have met the aliens, and they are us?"
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lol, you could put it that way.
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The comet origin's to life theory is the main one you heard of? That theory is a stretch brought on by those who were looking for anything other than trying to figure out how life works; it is hardly the major theory to life's origin's.
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yes, that is the major one, that ive heard of. how else do you explain the sudden onset of life?
it was also mentioned on cosmos, and in zubrins books. i guess zubrin doesnt know his space science.
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It's tempting, in view of how quickly life appears to have originated on Earth, to speculate that it arrived ready-made from space. In our present state of ignorance about how life got started, that explanation is as good as any!
But the problem with panspermia, as it's called, is that it's intellectually unsatisfying - simply skirting around the problem of bio-genesis on Earth by 'pushing it back' to another planet, or another star system, at some indeterminate time in the past. In other words, it doesn't address the real problem of how inanimate matter crossed the threshold into the realm of the living. In fact, it's a bit of a scientific cop-out in that sense!
Paul Davies, a world-renowned physicist, in his book "The Fifth Miracle", comes to the conclusion that our current state of theoretical knowledge is inadequate to explain how life arose. His argument is complex and I don't understand all of the details, but a key point is the difficulty of explaining how the extraordinary amounts of random-but-biologically-relevant information needed to create a genome could arise from chaos. This is a profound problem because a functional genome has, paradoxically, to be both random and highly specific in order to provide the vast amounts of information a functioning organism has to have.
Dr. Davies has decided there are fundamental laws of nature we currently know nothing about, which we will have to discover before we can understand the mystery of life's origins.
There is obviously something special about this particular universe which must predispose it towards life.
Fascinating, isn't it?!
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
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I do beleive I mentioned something about Stuart Kauffman's work; somehow that has slipped out of the discussion.
I have alway's said how Sagan's "Cosmos" is an underrated general science book amongst the scientific community; however, the comet theory is NOT the main theory of the origin of earthy life. Are those really your main references to this theory? If so, I can see where you are going wrong.
I'm going to at least give a hint here. Back in the day's of classical thermodynamics, entropy indicated everything decay's, yet the universe is ordering itself. One point anybody who actually carefully looked at the theory of thermodynamics points out is that entropy indicates everything decay's only in closed systems to energy and matter. Clearly, life is not a closed system. It took a hundred years for Ilya Prigogine to work out non-equilibrium thermodynamics and win a nobel prize for it. As he say's, untill we had chaos theory to analyse stable non-equilibrium states, we could not. Everything else is Stuart Kauffman's. Actually, I am recently excited by some further work along the lines of Stanley Miller's which is similar to what S. Kauffman's work indicates. I need to go find that copy I made from Scientific American again . . . .
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Hi Oker56,
I read some Stuart Kaufman articles a long time ago. If I remember well, he shows that spontaneous order, or low entropy subsystem as you would say now, can arise spontaneously from chaotic systems. In short, order from chaos. This is very interesting. I read also the "what is life" from Erwin Schrodinger and more recently, I plan to digest a book from Leon Brillouin, about the theory of information, entropy, and the link between information, entropy and energy.
Nobody ever tried to make a synthesis of all those theories toward a more palattable definition of life than just negentropic autoorganized systems ?
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Well, the thing about Prigogines stable non-equilibrium thermodynamic structures is that they are a very general class including everything from vortices of various kinds(like tornadoes and Jupiter hurricanes) to life, so what is the difference between life and a mere vortex? This was the only criticism of Prigogines work; that it didn't go far enough. Then came along Maturana and his autopoisis theory. They came to it from a round about way. I suppose I do to, but I like mine better, so i'll explain it my way.
I find Maturana's autopoisis theory similar to my idea's about perpetual motion machines. Really, I should define my idea and potentially perpetual machines. So long as the flow of energy and matter flow's through them and other physical conditions don't get to extreme like nova blasts and so on, my machines should keep running. Basically, when i started thinking about how to keep thing's running, I thought of the water wheel. You see i'm not suggesting creation of energy from nowhere; in fact, the more I thought about my ideas, the more I realized my ideas were just the renewable energy movement, but with a twist. While in an ideal world, the water wheel or any other renewable energy machine will keep on going, in our world there is friction, so the water wheel will eventually break its drive-shaft. The thing I thought of that led me to similar ideas to Maturana's autopiosis theory is making the water wheel power a robotic arm that can bend around perform certain maintenance. Now, it can only do so much, so I thought of a network of renewable energy maintenance machines all keeping each other going. This is the gist of Maturana's autopoisis theory. The only reason why these guy's havn't won a nobel prize and not talked about much is because it is very hard to compute the chemical networks of just one bacterial cell. See, a single cell is a network of molecular machines that make each other and the membrane that holds them together, and that is a distinction between Maturana's autopoisis theory and Manfred Eigen's(who has won a nobel prize for his theory of life) hypercycles theory. Hypercycles are observed in the laboratory. The only thing that keeps them together is the surrounding petre dish. They make all kind's of patterns and evolve.
So, the difference between Prigogine's stable non-equilibrium structures and life is that life is a network of chemical machines that make each other, but what about that computational problem. This is where Stuart Kauffman's work comes in which I've already described in a previous reply in this thread. Basically, there are no simple cells; they all start out as complex wholes, then they evolve into ever more complex cells the way Prigogine describes stable non-equilibrium structures do; you push them to an instability point(chaos theory), and they develop growth's and stabilize that with feedback loops to the rest of the environment.
So, life is an inevitable formation in the right environment. In other words not just here on earth and not just in the core of a comet, but both. As for mars, maybe there's a few frozen fossil cells, but probably very few, and most of those probably will be cometary debre, and notice how the cometary bacteria that maybe do get down to mars surface obviously don't take over the planet's atmosphere; hence, they don't survive.
There's plenty more to say, but I've got to go.
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I don't know Leon Brillouin, but I do remember and have Jeremy Campbell's "The Grammatical Man." It had been on science bookstore shelves for years in the 80's. It has much about on a general level. I know Chaos theory uses information theory from James Gleik's Chaos theory.
I'm not up there mathematically yet, but thing's should start picking up.
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I want to refute one myth. It is NOT too cold on mars. Mars is very warm in the planetary scheme of things.
During the equator in the summer it isnt uncommon for the temperature to reach 60F at peak daytime. During the winter -80F.
Thats cold but we have extremes on earth like that.
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It is highly unlikely that life will spring while the temperature is below the freezing point of water since it is felt that it is a necessary ingredient for life or at least its amino acids to form.
A temperature that is 60 would I think be fine if it where sustained for a long period of time while water did exist.
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