doG Posted August 14, 2007 Posted August 14, 2007 Recent probes inside comets show it is overwhelmingly likely that life began in space, according to a new research paper by Cardiff scientists. Professor Chandra Wickramasinghe and colleagues at the Cardiff Centre for Astrobiology have long argued the case for panspermia – the theory that life began inside comets and then spread to habitable planets across the galaxy. A recent BBC Horizon documentary traced the development of the theory. Now the team claims that findings from space probes sent to investigate passing comets reveal how the first organisms could have started. More at Cardiff University....
Sisyphus Posted August 14, 2007 Posted August 14, 2007 That really is amazing, but I wish I knew how they calculated those odds. 10^24 to 1? Seriously? What factors could possibly give you that result? If it is true, though, it's wonderful news. It would mean there's probably still life in comets, right? And if that's the case, then we'd have good chances of finding it wherever it could be supported, just because comets crash into stuff. Also, I guess we should expect lots more missions to passing comets...
jackson33 Posted August 14, 2007 Posted August 14, 2007 If I read the article, they are saying almost certainly life formed on comets. First, all material comets/meteor are thought to have formed or had been part of something that formed about the time our planet did. If you want to stretch the issue, I suppose its possible a life bearing planet could have existed 1-3 billion years ago and for some reason disintegrated. Another possibility, though off the average reservation, is that living organisms could form during the process of the stars formation, where pressures heat and electrical charges would be the greatest. Just a thought...
Sisyphus Posted August 14, 2007 Posted August 14, 2007 where pressures heat and electrical charges would be the greatest. Just a thought... But wouldn't that make it least likely?
pioneer Posted August 14, 2007 Posted August 14, 2007 The comets shows how easy it is to form amino and nucleic acids. The truth is, science can not explain the formation of life on earth. The comet is a fudge factor to help gloss over the lack of good theory to explain how things on earth could amount to life. But it still does not address how comets got their life to starte in the first place. If it came from a former planet that broke up, how did that get its life started? By using comets, since data is much more difficult to get, than on the earth, by many orders of magnitude, it gives speculation more freedom, since almost all new theory becomes even more difficult to disprove. On earth, we can do the test much easier and come to the truth. With comets one can always say we need a different type of comet. If costs a trillion dollars to farm all the comet types, then speculation will linger. That is all well and good, but it can create bias that circumvents good theory. Let me give you the key bias that is messing up sciences ability to form life on earth without the need of comets. It has to do with fossil fuels. The assumption is, the fossil fuel stems from ancient animals and plants. Look at fossil fuels logically, when animals die in the woods, there is natural recycle going on. The scavengers eat, then the bugs, then bacteria. When this is done, there is only bones left to make petroleum? Dead thing stink for a reason, which is to attract recycle. When a tree falls in the forest, after the termites and bacteria are done, we have compost. This becomes food and nutrients for the next generation. The little that is left over, becomes all the coal in the world? Even if trace upon trace, adds up to something substantial, why does petroleum typcially form major deposits? Do animals die in a pile? Does this happen even under the oceans? Or were their bacteria dead zones? In other words, if we found traces of oil and coal everywhere and not concentrated into deposits, then the logic of fossils might make sense. An alternate explanation of these deposits, is the early earth produced the materials for these deposits before life was on the earth. From this vast range of organic materials life emerged.Life then used this as part of its food, changing the carbon dating, to create the illusion that this formed at the times we think it did. The earth forms deposits of other minerals, instead of even distribution. Organics deposits is consistent with this. If we forget about the fossil fuel bias, and look at the ancient earth making gunk and goop before life, we have a lot more starting material. The fossil fuel is an advance or processed version of the gunk-goop. The tar pits wth dinosaur remains were not the burial caldrons of dino's, but a sticky pool of earthy tar that many dinosaurs fell into and added to. The scavengers, bugs and bacteria had enough sense to let it be. This is more logical way to preserve/add and avoid the restraints of bio-recycle. Here is an old engineering trick for separating light weight organics from heavier oils, that could have allowed the earth can separate the goop from the gunk. It is called steam distillation. If you bubble steam through the goop-gunk, the light weights organics will go up with the steam, at lower than expect boiling point, i.e, less heat destructive. For example, If you mix kerosene and heavy oil and steam lance it, all the kerosene will come off with the steam below it boiling point, leaving the thicker oil behind. The light weight will condense, phase separate and become concentrated. If one was to assume the earth making gunk and goop before life, than the original composition of gunk and goop had a lot of raw materials at a wide range of molecular weights. The steam distilled light materials could then condense higher up in the sky. Some of it will fall and get beat and churned by the rough ocean waves. This makes an emulsion that becomes more and more stable, i.e., lotion of life. It is not life yet but we now have a brought spectrum of materials to get started. The bias of fossil fuels makes less material for pre-life. So now science has to leave the earth and look elsewhere in an attempt to compensate. The result is one bias leading to another and another and another, etc.,
foodchain Posted August 14, 2007 Posted August 14, 2007 The comets shows how easy it is to form amino and nucleic acids. The truth is, science can not explain the formation of life on earth. The comet is a fudge factor to help gloss over the lack of good theory to explain how things on earth could amount to life. But it still does not address how comets got their life to starte in the first place. If it came from a former planet that broke up, how did that get its life started? By using comets, since data is much more difficult to get, than on the earth, by many orders of magnitude, it gives speculation more freedom, since almost all new theory becomes even more difficult to disprove. On earth, we can do the test much easier and come to the truth. With comets one can always say we need a different type of comet. If costs a trillion dollars to farm all the comet types, then speculation will linger. That is all well and good, but it can create bias that circumvents good theory. Let me give you the key bias that is messing up sciences ability to form life on earth without the need of comets. It has to do with fossil fuels. The assumption is, the fossil fuel stems from ancient animals and plants. Look at fossil fuels logically, when animals die in the woods, there is natural recycle going on. The scavengers eat, then the bugs, then bacteria. When this is done, there is only bones left to make petroleum? Dead thing stink for a reason, which is to attract recycle. When a tree falls in the forest, after the termites and bacteria are done, we have compost. This becomes food and nutrients for the next generation. The little that is left over, becomes all the coal in the world? Even if trace upon trace, adds up to something substantial, why does petroleum typcially form major deposits? Do animals die in a pile? Does this happen even under the oceans? Or were their bacteria dead zones? In other words, if we found traces of oil and coal everywhere and not concentrated into deposits, then the logic of fossils might make sense. An alternate explanation of these deposits, is the early earth produced the materials for these deposits before life was on the earth. From this vast range of organic materials life emerged.Life then used this as part of its food, changing the carbon dating, to create the illusion that this formed at the times we think it did. The earth forms deposits of other minerals, instead of even distribution. Organics deposits is consistent with this. If we forget about the fossil fuel bias, and look at the ancient earth making gunk and goop before life, we have a lot more starting material. The fossil fuel is an advance or processed version of the gunk-goop. The tar pits wth dinosaur remains were not the burial caldrons of dino's, but a sticky pool of earthy tar that many dinosaurs fell into and added to. The scavengers, bugs and bacteria had enough sense to let it be. This is more logical way to preserve/add and avoid the restraints of bio-recycle. Here is an old engineering trick for separating light weight organics from heavier oils, that could have allowed the earth can separate the goop from the gunk. It is called steam distillation. If you bubble steam through the goop-gunk, the light weights organics will go up with the steam, at lower than expect boiling point, i.e, less heat destructive. For example, If you mix kerosene and heavy oil and steam lance it, all the kerosene will come off with the steam below it boiling point, leaving the thicker oil behind. The light weight will condense, phase separate and become concentrated. If one was to assume the earth making gunk and goop before life, than the original composition of gunk and goop had a lot of raw materials at a wide range of molecular weights. The steam distilled light materials could then condense higher up in the sky. Some of it will fall and get beat and churned by the rough ocean waves. This makes an emulsion that becomes more and more stable, i.e., lotion of life. It is not life yet but we now have a brought spectrum of materials to get started. The bias of fossil fuels makes less material for pre-life. So now science has to leave the earth and look elsewhere in an attempt to compensate. The result is one bias leading to another and another and another, etc., Well, even the most basic life we have on earth currently such as prokaryotes in my opinion is probably a large evolution from whatever really primitive life was like, purely opinion. Now I know that complex organic aromatic compounds have been found in space among with other amino acids, but I don’t know where this is going with it all. Maybe the way life on earth came about is not the same as it did somewhere else? Who is to say really, or more or less why do things have to be simple and elegant? What I don’t understand is simply comets bring life to earth, surely I am not getting the article confused with peoples posts. I don’t know of anything living that would survive a comet impacting on say a body like earth. I don’t even know of any experiments we can do which would gauge what such an impact would yield truly. Now if the article is just about comets bringing basic building blocks of life to earth as we understand it, such as various organic compounds, well to me that seems more feasible. There are such theories behind how a deal of water made its way to earth. Primitive fish that had a scale like system similar to modern fish scales, or the primitive scales themselves were inorganic compounds actually, so maybe a fallacy that is being labored about is saying life needs a certain chemistry to exist possibly? I mean to me talking about chemistry is somewhat a moot point, for you can do that with a grand scale of things that happen to be made out of matter. I think a more real question would be how to get something to sustain and reproduce itself. The laws of physics happen to be ever present as far as I know, so "life" would always be faced with that, such as thermal energy. I mean from what is understood so far factually about evolution most any thought on the subject from that points to origins that are even more primitive, its just that such is probably not a simple or elegant thing, and more or less it would be easy on my part to suggest that whatever scientists studying such might not even be doing it with the right questions, such as thinking you have to have a certain chemistry, not to mention what was the environment in terms of structure or energy, such as maybe a certain type of rock formation in a certain location was paramount to the foundation of life on earth, but over billions of years, how do you find out exactly. TO add to this maybe the process that lead to life itself took millions of years or longer... The list really could go on.
Paralith Posted August 15, 2007 Posted August 15, 2007 What I don’t understand is simply comets bring life to earth, surely I am not getting the article confused with peoples posts. I don’t know of anything living that would survive a comet impacting on say a body like earth. I don’t even know of any experiments we can do which would gauge what such an impact would yield truly. Now if the article is just about comets bringing basic building blocks of life to earth as we understand it, such as various organic compounds, well to me that seems more feasible. There are such theories behind how a deal of water made its way to earth. I think you are right, they're talking more about the building blocks of life on comets than organisms themselves. As you say, scientists are having difficulty figuring out how the first organic molecules of appreciable complexity to have some form of reproduction first formed on Earth (and that definitely would be a "required chemistry" ). Once you have those, figuring out the path to organisms isn't quite as difficult.
Bluenoise Posted August 15, 2007 Posted August 15, 2007 Yeah I don't buy it. First of all life needs a renewing energy source to sustain itself. And I can't possibly thing what they maybe suggestion in serving that function inside a comet. Except for the surface where there might be light from the sun etc. However unfortunately the surface of a comet would be so bathed in radiation that it and a good few feet below the surface would be constantly sterilized. I'm pretty convinced that earth is by far the best place in the solar system for life to form, and I think the chance of it forming in comets and seeding the earth is pretty null. Edit* Now having said that. I think it's entirely possible that comets played a role in seeding the earth with minerals and small molecules water etc that was fundamental to the eventual formation of life. I think it's highly likely actually. The early earth was only a tiny fraction of the mass that it is now anyways. But I think that's the extent of their possible part.
foodchain Posted August 15, 2007 Posted August 15, 2007 Now I don’t know if this has anything to do with the topic but this is a pretty darn cool little organism. "Ability to Resist Environmental Extremes While in a state of cryptobiosis tardigrades are able to resist environmental extremes that would be instantly letha to animals if in the active state. In 1842, the French naturalist Doyere first discovered tardigrades were able to withstand being heated for a few minutes to 125 °C, later Rham in 1929 increased this figure to 150°C. Adults have been able to survive being cooled to temperatures of almost absolute zero (-272.8°C) where there is no free molecular vibration and so no metabolism can exist. While in this state the organisms are also greatly resistant to X-Rays of 570,000 Roentgens (only 500 Roentgens would be fatal to a human). Water bears are also resistant to a vacuum (like outer space), some noxious chemicals, boiling alcohol, and pressures six time greater than the bottom of the deepest ocean etc." http://www.museums.org.za/bio/tardigrades/index.htm
Royston Posted August 15, 2007 Posted August 15, 2007 I think you are right, they're talking more about the building blocks of life on comets than organisms themselves. As you say, scientists are having difficulty figuring out how the first organic molecules of appreciable complexity to have some form of reproduction first formed on Earth (and that definitely would be a "required chemistry" ). Once you have those, figuring out the path to organisms isn't quite as difficult. It's a poor article... 'panspermia – the theory that life began inside comets', panspermia is just the idea that life started due to intervention from something from space e.g amino acids from meteors / comets et.c, could be a candidate, but it's one of those open to interpretation terms, and certainly not specific to the interior of comets. As Bluenoise pointed out, there is no renewable energy source on comets, even Thermophiles, that are a candidate as the first organisms on Earth, and would of hardly felt a speck of sunlight, need the hot vents found deep in the oceans to survive. I think the article is implying that it's more likely (although 10^24 more likely ?!?) that some of the building blocks of life would of come from the collisions of comets on Earth, rather than solely Earth itself.
Bluenoise Posted August 15, 2007 Posted August 15, 2007 Yeah I don't buy it. First of all life needs a renewing energy source to sustain itself. And I can't possibly thing what they maybe suggestion in serving that function inside a comet. Except for the surface where there might be light from the sun etc. However unfortunately the surface of a comet would be so bathed in radiation that it and a good few feet below the surface would be constantly sterilized. I'm pretty convinced that earth is by far the best place in the solar system for life to form, and I think the chance of it forming in comets and seeding the earth is pretty null. Edit* Now having said that. I think it's entirely possible that comets played a role in seeding the earth with minerals and small molecules water etc that was fundamental to the eventual formation of life. I think it's highly likely actually. The early earth was only a tiny fraction of the mass that it is now anyways. But I think that's the extent of their possible part. I know quoting myself isn't a good idea... But I just want to apologize for my poor spelling and grammar in that post. I reread it and almost threw up.
CDarwin Posted August 15, 2007 Posted August 15, 2007 There are bacteria that live in rocks deep in the crust.
pioneer Posted August 15, 2007 Posted August 15, 2007 Another reason we now need to go to the comets for life materials and even the water on the earth, is that current solar system genesis theory got changed. They got rid of the old sun/solar system formation theories, which had provided all that was needed, in favor of supernova remnants. The new logic is the solar system is the supernova pieced back together, more or less, via debris recolliding where our solar system is. The space debris in the form of comets and asperoids gives us the iron for the iron core of the earth, the earth's water and now even life itself. It became a theoretical chain reaction. The physics represents an advance in thinking, but some of the logic has a major conceptual problem. Here it is. The center of a dieing star is assumed to form an iron core as the nuke fuel materials are used up. Iron is very dense and is the last exothermic atom to form. After that atoms become endothermic. This terminal atom means the end of the line for ouptut and sinks due to its high density. The connceptual problem is iron has too high of an atomic weight to be fully ionized at the temperatures of a star core. If Iron has any electrons in the inner most orbitals, its density becomes less. In other words, iron with even 2, 1S electrons is a walnut in a football field. All it takes is 26 or so, H-protons or grapes in the footaball field to be denser. Density is mass/volume. So a smaller mass/smaller volume can add up denser then a higher mass with a much higher effective volume. Or 27 grapes in a football field is denser than one large walnut in the same volume. Using better conceptual consistency, here is the way this extrapolates. The sun becomes the second life of a first generation star. The floating iron (plus orbital electrons) above the denser H fusion core, becomes an effective shield that is holding in energy that needs to vent. Eventually Sun-1's pressure builds until it blows big chunks away. After the sun the cleared the exhaust vent, what was left over was Sun-2 as gravity pulls it back into shape. The ejected materials becomes the debris for the solar system. The rarity of stars with solar systems indicates that either most are first generation stars, or most second generaton stars blew their stack just a little too much, to keep their materials close enough to form their own solar systems. The sun and solar system amounts to localized remanants of a mini-supernova. If we assume all the material ejected had the same momentum, the heavier stuff would not go as far and would form the rocky inner planets. The asteroid belt after Mars may have been the affect range of the bulk of the rocky junk. The ligher gases where ejected much farther to become the gas giants. When all was said and done the earth had the periodical table to work with. The sun may have taken time to stabilzed allowing planetary formation more autonomy at first.
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