Frank Merton Posted May 14, 2014 #26 Share Posted May 14, 2014 My problem is that comets and asteroids do not come from interstellar space but from within the solar system, and in fact the distance between the outermost comets and another solar system vastly exceeds the orbits of the comets. Now it might be that occasionally a comet gets thrown into interstellar space after grazing the upper atmosphere of an "infected" planet and picks up some hardy spores (they would have to be really damn hardy as the trip is going to last tens of millions of years even if its trajectory is straight at a very close star, and organic material naturally decays over much shorter periods just by random atomic oscillations). Another possibility is exchange of cometary material during the evolution of an open star cluster before the stars have gotten very far apart -- the situation of most young stars -- but still they will be large distances even then and so young we wonder if life would have evolved in any part of the cluster yet. In short I think far and away the simplest conclusion is that we did not need to be seeded by living things: that it originated on the earth or maybe Mars and that was enough. Comets may have seeded us with organic materials such as amino acids, but that would also not be necessary as we are well aware that the earth's early atmosphere would have had plenty of those on its own anyway. 4 Link to comment Share on other sites More sharing options...
+DieChecker Posted May 14, 2014 #27 Share Posted May 14, 2014 (edited) It seems reentry would be very harmful to prospective life. Has any experiments been conducted to show possibility of survival? And I always thought it was better to exhale completely if headed into a vacuum. Tons and tons of dust comes to Earth every year from space. Stuff burns up in the atmosphere due to friction with air and due to usually very fast speeds. Stuff that is very light usually will hit the outer atmosphere and almost immediately slow down. Then dust slowly falls to the ground, because it's terminal velocity is very slow. I'm not sure where a tardigrade would fall in a re-entry situation, but I think it would be a lot closer to dust then to even something like a dropped bolt. Those guys are so tiny, they would probably slow down immediately and drift gently and slowly to the ground. Edited May 14, 2014 by DieChecker Link to comment Share on other sites More sharing options...
Frank Merton Posted May 14, 2014 #28 Share Posted May 14, 2014 Yea, the "burning up" bit is a false issue; there are plenty of other problems though. Link to comment Share on other sites More sharing options...
HappyMonkey Posted May 14, 2014 #29 Share Posted May 14, 2014 Tons and tons of dust comes to Earth every year from space. Stuff burns up in the atmosphere due to friction with air and due to usually very fast speeds. Stuff that is very light usually will hit the outer atmosphere and almost immediately slow down. Then dust slowly falls to the ground, because it's terminal velocity is very slow. I'm not sure where a tardigrade would fall in a re-entry situation, but I think it would be a lot closer to dust then to even something like a dropped bolt. Those guys are so tiny, they would probably slow down immediately and drift gently and slowly to the ground. Even tardigrades can only survive a relatively short period. In order to survive long enough to enter the atmosphere they'd have to be protected in something. 1 Link to comment Share on other sites More sharing options...
+DieChecker Posted May 14, 2014 #30 Share Posted May 14, 2014 Even tardigrades can only survive a relatively short period. In order to survive long enough to enter the atmosphere they'd have to be protected in something. Do we really know that? Has an experiment been done? I do agree that it is very likely that even a tardigrade would die if just dumped off in low orbit and allowed to fall to Earth. Link to comment Share on other sites More sharing options...
theotherguy Posted May 14, 2014 #31 Share Posted May 14, 2014 Humans surviving in space? You got about five minutes before the pressure differential causes the worst case of the bends you'll ever experience. You might survive if you're extremely lucky, but you won't be functioning quite as well as before. If you're out there for unprotected for two minutes, all surface moisture--eyes, mouth, any orifice you care to think about--will dehydrate, and your brain will be running on borrowed time. This is the approximate threshold for survival with no permanent damage. As for microbes and tiny, simple creatures, if they were encased in the center of an asteroid, they would probably have a pretty good chance. This is just speculation, but a rocky/metallic barrier could protect a life form for long enough to survive atmospheric entry speed and heat. Bonus points if they have a protective shell or membrane or are dormant. 2 Link to comment Share on other sites More sharing options...
AtlantisRises Posted May 14, 2014 #32 Share Posted May 14, 2014 A problem I have with this idea is that it really only moves the question back one step. If life came to Earth on the back of a comet that had picked it up on Mars or Europa or perhaps from a star system an incredible distance away it still doesn't explain how life originated on that planet. Personally I think it unlikely for any form of life to survive in space for the length of time needed to get from even a 'nearby' star system but it doesn't really matter that much. 1 Link to comment Share on other sites More sharing options...
HappyMonkey Posted May 14, 2014 #33 Share Posted May 14, 2014 Do we really know that? Has an experiment been done? I do agree that it is very likely that even a tardigrade would die if just dumped off in low orbit and allowed to fall to Earth. I did a check, and it looks like in open space they can only survive ten days due to the extremes, and these are some of the hardiest forms of life we know. Without some form of protection they'd die very quickly. 2 Link to comment Share on other sites More sharing options...
psyche101 Posted May 14, 2014 #34 Share Posted May 14, 2014 They're able to survive in space due to their hibernation cycle, but exposed reentry would seem to be a problem. I know internally the space rocks don't heat up, but it'd seem to be hard for microorganisms to be in the safe interior of the meteorite, though I suppose a comet might be a better bet. Most of what I've read talks about the building blocks of life, amino acids, not full lifeforms. I thought rather than hibernation, it's a bizarre form of Dehydration, I'm honestly not sure if they are the same thing or not. I would only assume in a Comet, the OP's parameters are a bit wide pen for serious consideration of Panspermia carrying even so much as a Tardigrade from planet to planet, he would not be the first though, an amateur Tardigrade enthusiast - Mike Shaw attributed their hardy values to them being alien life forms. Not the case though. Link to comment Share on other sites More sharing options...
psyche101 Posted May 14, 2014 #35 Share Posted May 14, 2014 My problem is that comets and asteroids do not come from interstellar space but from within the solar system, and in fact the distance between the outermost comets and another solar system vastly exceeds the orbits of the comets. Interstellar Comets are conjectured to exist, but we have no known examples. Link to comment Share on other sites More sharing options...
psyche101 Posted May 14, 2014 #36 Share Posted May 14, 2014 (edited) I did a check, and it looks like in open space they can only survive ten days due to the extremes, and these are some of the hardiest forms of life we know. Without some form of protection they'd die very quickly. That's not quite right, in 2007 European researchers sent Tardigrades into space for 10 days and most of them survived, we do not know what their limits are. I know that some have been revived in dry moss after being in their dehydrated state for 100 years. That's not going to cut the mustard in space though, we would be talking thousands of years at a minimum. Even so, with the ones that did spend ten days in LEO, not all of them survived. It's not a given that any Tardigrade will survive the vacuum of space - we have seen some do it. LINK - Current Biology - Tardigrades survive exposure to space in low Earth orbit . Edited May 14, 2014 by psyche101 1 Link to comment Share on other sites More sharing options...
HappyMonkey Posted May 14, 2014 #37 Share Posted May 14, 2014 According to wikipedia, the technical term is cryptobiosis. Also wiki has a list of microorganisms that have been tested in space: http://en.wikipedia.org/wiki/List_of_microorganisms_tested_in_outer_space Some have been tested in reentry through atmosphere and survived, so my point was moot. 1 Link to comment Share on other sites More sharing options...
psyche101 Posted May 14, 2014 #38 Share Posted May 14, 2014 (edited) According to wikipedia, the technical term is cryptobiosis. Also wiki has a list of microorganisms that have been tested in space: http://en.wikipedia...._in_outer_space Some have been tested in reentry through atmosphere and survived, so my point was moot. Crikey!! I had no idea how many had been to space! Cheers for that link mate! Nice One. There we go learn something everyday here!! Cryptobiosis!! My new lesson for today, thanks again Happy Monkey!! Edited May 14, 2014 by psyche101 1 Link to comment Share on other sites More sharing options...
qxcontinuum Posted May 14, 2014 Author #39 Share Posted May 14, 2014 (edited) So actually a few steps closer to my idea becoming reality... looks like not just my idea since there is a scientific claim and similarity...well i was about this close to became renown! Just to recap; bacteria’s can live up to 10 days in outta space under normal conditions, tests have been made. But in an icy comet they can be dormant even for millions of years. For those that would say not...here is a reference I am making to the following article; "Scientists Revive Ancient Bacteria Oct. 18 By Matthew Fordahl In what sounds like something out of Jurassic Park, bacteria that lived before the dinosaurs and survived Earth’s biggest mass extinction have been reawakened after a 250-million-year sleep in a salt crystal, scientists say. http://abcnews.go.co...story?id=119865 Edited May 14, 2014 by qxcontinuum Link to comment Share on other sites More sharing options...
lost_shaman Posted May 14, 2014 #40 Share Posted May 14, 2014 "It did not happen here, and the plants and animals are a product if the environment, stromatolites indicate life started here, small and in water. " Stromatelites only show that they were established here, not that life originated here. 1 Link to comment Share on other sites More sharing options...
psyche101 Posted May 15, 2014 #41 Share Posted May 15, 2014 (edited) "It did not happen here, and the plants and animals are a product if the environment, stromatolites indicate life started here, small and in water. " Stromatelites only show that they were established here, not that life originated here. Gidday Mate You are missing one small part of this picture, the OP is talking about macro life. Not the start of life, he seems to be under the impression that a comet or meteor can whack the planet, encase some plants and animals, and deposit them on another world and duplicate an ecosystem. He stated in post #21 that "it really is that simple" But I have a feeling he was referring to his intellect. That what I mean, life here and now started small, and in the oceans. I agree that Abiogenesis is anyones guess at this stage. I don't think the OP is up to Abiogenesis yet. Which is plainly nonsense. Cheers. Edited May 15, 2014 by psyche101 Link to comment Share on other sites More sharing options...
psyche101 Posted May 15, 2014 #42 Share Posted May 15, 2014 So actually a few steps closer to my idea becoming reality... No. The Panspermia Hypothesis has been in stasis since it's conception. What has happened is you have finally realised that which has been posted here upteen times. looks like not just my idea since there is a scientific claim and similarity... Never was your idea. Your version of Panspermia moving macro species is simply preposterous, you should have read the links I left and educated yourself on the subject. Hell, I was the one who told you what your "idea" was called. And considering how often it has been discussed here before, I think your subconscious is quite possibly where you pulled this epiphany from. well i was about this close to became renown! Just no. Your idea of animals and plants being shot all over the galaxy by comets and meteors is pure nonsense. Microbial life is the absolute limit of possibilities. Just to recap; bacteria’s can live up to 10 days in outta space under normal conditions, tests have been made. But in an icy comet they can be dormant even for millions of years. For those that would say not...here is a reference I am making to the following article; "Scientists Revive Ancient Bacteria Oct. 18 By Matthew Fordahl In what sounds like something out of Jurassic Park, bacteria that lived before the dinosaurs and survived Earth’s biggest mass extinction have been reawakened after a 250-million-year sleep in a salt crystal, scientists say. http://abcnews.go.co...story?id=119865 Read more. That's what the hypothesis of Panspermia consists if, the transportation of microbial life. That could be determined if it happened. Your link also says: “Unlike amber or rocks or permafrost, salt is not an impermeable material,” he said. And that is not whole animals, which you said "it's as simple as that" about. Even these microbes require a certain environment. If you actually want to learn more about that type of long lived life, you should Google Lake Vostok. 1 Link to comment Share on other sites More sharing options...
DONTEATUS Posted May 15, 2014 #43 Share Posted May 15, 2014 So I guess that just about cuts out my discovery of life inside my Home made Beef Jerky ? Albeit Oh ! So Yummy ! 1 Link to comment Share on other sites More sharing options...
+DieChecker Posted May 15, 2014 #44 Share Posted May 15, 2014 One thing I thought about was that Earth is a pretty easy place to survive in. Plenty of water, food, sun.... If a life form evolved on a more desolate, drier, hotter, harder to find food... kind of world, perhaps they would be a lot tougher then Earth creatures and would have little trouble hibernating and traveling through space on some debris blown off their home world. Just supposition, but logical..... 2 Link to comment Share on other sites More sharing options...
badeskov Posted May 15, 2014 #45 Share Posted May 15, 2014 One thing I thought about was that Earth is a pretty easy place to survive in. Plenty of water, food, sun.... If a life form evolved on a more desolate, drier, hotter, harder to find food... kind of world, perhaps they would be a lot tougher then Earth creatures and would have little trouble hibernating and traveling through space on some debris blown off their home world. Just supposition, but logical..... Yeah, my personal (and completely uneducated opinion) is that life is a lot more adaptable that we give it credit for. Cheers, Badeskov 2 Link to comment Share on other sites More sharing options...
HappyMonkey Posted May 15, 2014 #46 Share Posted May 15, 2014 You'd still have to get past the vast amounts of time and temperature and radiation. 2 Link to comment Share on other sites More sharing options...
Frank Merton Posted May 15, 2014 #47 Share Posted May 15, 2014 Panspermia is an unnecessary and complicated and barely marginal (scientific) idea. It is much simpler to posit that we originated here but haven't been able to determine exactly how (by what chemical route) it happened because all the evidence has long since disappeared. All we can say is that the atmosphere was different then ("reducing"-- meaning with little if any free oxygen) so that complicated organic molecules could survive millions of years in an ocean that in effect becomes a soup of organic molecules. Given the massive time available, that self-replicating molecules would appear is a reasonable idea. Once they exist evolution would set in, steadily improving these molecules and their ability to duplicate themselves. 2 Link to comment Share on other sites More sharing options...
qxcontinuum Posted May 15, 2014 Author #48 Share Posted May 15, 2014 (edited) You'd still have to get past the vast amounts of time and temperature and radiation. since on earth scientist have revived bacteria from 250 millions years ago. It is possible. Also encrusted in an icy comet or insight a meteorite these will be protected against radiations and all the stress factors in cosmos. In the same time in 250 million of years traveling at higher speed a meteorite can probably cross 3 galaxies. In the same time recently there was an air balloon lifted up in space and when it came down on earth they found a lot of alien bacterias on it. There is a growing community of scientists claiming that bacteria can travel through space Edited May 15, 2014 by qxcontinuum Link to comment Share on other sites More sharing options...
Frank Merton Posted May 15, 2014 #49 Share Posted May 15, 2014 Yea I don't say panspermia is impossible, just not the probable origin of life here. 1 Link to comment Share on other sites More sharing options...
toast Posted May 15, 2014 #50 Share Posted May 15, 2014 (edited) In the same time recently there was an air balloon lifted up in space and when it came down on earth they found a lot of alien bacterias on it. Gas balloons can operate up to the stratosphere but not in space and the hypothesis (placed by Prof.Wickramasinghe) you are talking about, alien bacteria in the earth atmosphere, is still a hypothesis so it cannot be claimed that the found bacteria are of extraterrestrial origin. Edited May 15, 2014 by toast 1 Link to comment Share on other sites More sharing options...
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