Comets and The Origins of Life

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Published on August 14th, 2007, 10:48 am
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http://www.eurekalert.org/pub_releases/2007-08/cu-cpr081407.php
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Cardiff University

Comet probes reveal evidence of origin of life, scientists claim
Recent probes inside comets show it is overwhelmingly likely that life began in space, according to a new paper by Cardiff University scientists.

Professor Chandra Wickramasinghe and colleagues at the University’s 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 formed.

The 2005 Deep Impact mission to Comet Tempel 1 discovered a mixture of organic and clay particles inside the comet. One theory for the origins of life proposes that clay particles acted as a catalyst, converting simple organic molecules into more complex structures. The 2004 Stardust Mission to Comet Wild 2 found a range of complex hydrocarbon molecules - potential building blocks for life.

The Cardiff team suggests that radioactive elements can keep water in liquid form in comet interiors for millions of years, making them potentially ideal “incubators” for early life. They also point out that the billions of comets in our solar system and across the galaxy contain far more clay than the early Earth did. The researchers calculate the odds of life starting on Earth rather than inside a comet at one trillion trillion (10 to the power of 24) to one against.

Professor Wickramasinghe said: “The findings of the comet missions, which surprised many, strengthen the argument for panspermia. We now have a mechanism for how it could have happened. All the necessary elements - clay, organic molecules and water - are there. The longer time scale and the greater mass of comets make it overwhelmingly more likely that life began in space than on earth.”


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The new paper, The Origin of Life in Comets, by Professor Wickramasinghe, Professor Bill Napier and Dr Janaki Wickramasinghe is to be published shortly by the International Journal of Astrobiology.


I like the way they use the phrase "overwhelmingly likely". It leaves very little room for doubt or questioning the basic premise. The evidence supporting this must be staggering.
Life is 10% what happens to you and 90% how you "choose" to respond to it.

SouthernFriedInfidel wrote: If you believe things that are contradicted by the evidence, then you are on a path built on falsehoods.
August 14th, 2007, 10:48 am
 
It's been long known that amino acids -- the basic building blocks for DNA -- exist naturally in star-forming nebulae. It should be easy to understand that given enough time and energy, elementary precursors of life could become readily available to any planet after a solar system forms. It's inevitable that life exists all over the place "out there."

Now as to whether it's better off than what we have here... that's quite an open question, isn't it?
August 14th, 2007, 11:02 am
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This show, Science Friday August 10:Hour 1 , discusses the fact that the older bacterial DNA found under Antarctic ice has been damaged and they say it's due to cosmic radiation. They also make the point that cosmic radiation could have detrimental effects on any DNA hitchhiking on certain comets. Interesting subject, as are the article and this radio show. The show at this time is not available for download at their site though, but one can obtain it via ITUNES for free.
August 16th, 2007, 5:20 pm
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Nfidel wrote:This show, Science Friday August 10:Hour 1 , discusses the fact that the older bacterial DNA found under Antarctic ice has been damaged and they say it's due to cosmic radiation. They also make the point that cosmic radiation could have detrimental effects on any DNA hitchhiking on certain comets. Interesting subject, as are the article and this radio show.

This makes me wonder about the idea that life actually originated in space and came to earth on a comet or something. Weren't the conditions on primordial earth pretty conducive to the emergence of life?
August 18th, 2007, 7:19 pm
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Questioner wrote:This makes me wonder about the idea that life actually originated in space and came to earth on a comet or something. Weren't the conditions on primordial earth pretty conducive to the emergence of life?


From the little I understand about it, yes. Especially when one considers anaerobic bacteria, Archaeobacteria and other extremophiles that they seem to find more of daily.
August 18th, 2007, 9:10 pm
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Nfidel wrote:
Questioner wrote:This makes me wonder about the idea that life actually originated in space and came to earth on a comet or something. Weren't the conditions on primordial earth pretty conducive to the emergence of life?


From the little I understand about it, yes. Especially when one considers anaerobic bacteria, Archaeobacteria and other extremophiles that they seem to find more of daily.

I read somewhere that the primordial plant life forms took in CO2 and gave off 02 very much like plants do today. But since they ended up giving off so much 02, they poisoned the earth for the anerobes. The 21% or so oxygen in the atmosphere made it extremely hard for the anerobic archaeobacteria, who ended up having to find anerobic environments (say, like in our bodies making us sick sometimes, symbiotically healthy at others). If that is true, it shows that life has been a major force in creating the environmental conditions necessary for aerobic life, like fish and mammals and such.
August 19th, 2007, 8:38 pm
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