Sub-surface Oceans In Early Comets Suggest Possible Origin of Life
Written by Brian Ventrudo
A new study claims early comets contained vast interior oceans of liquid water that may have provided the ideal conditions for early life to form.
In a paper published in the International Journal of Astrobiology, Professor Chandra Wickramasinghe and his colleagues at the Cardiff Centre for Astrobiology suggest the watery environment of early comets, together with the vast quantity of organics already discovered in comets, would have provided ideal conditions for primitive bacteria to grow and multiply during the first 1 million years of a comet's life.
The Cardiff team has calculated the thermal history of comets after they formed from interstellar and interplanetary dust approximately 4.5 billion years ago. The formation of the solar system itself is thought to have been triggered by shock waves that emanated from the explosion of a nearby supernova. The supernova injected radioactive material such as Aluminium-26 into the primordial solar system and some became incorporated in the comets. Professor Chandra Wickramasinghe together with Drs Janaki Wickramasinghe and Max Wallis claim that the heat emitted from radioactivity warms initially frozen material of comets to produce subsurface oceans that persist in a liquid condition for a million years.
Professor Wickramasinghe said: "These calculations, which are more exhaustive than any done before, leaves little doubt that a large fraction of the 100 billion comets in our solar system did indeed have liquid interiors in the past.
Comets in recent times could also liquefy just below their surfaces as they approach the inner solar system in their orbits. Evidence of recent melting has been discovered in recent pictures of comet Tempel 1 taken by the "Deep Impact" probe in 2005."
The existence of liquid water in comets gives added support for a possible connection between life on Earth and comets. The theory, known as cometary panspermia, pioneered by Chandra Wickramasinghe and the late Sir Fred Hoyle argues the case that life was introduced to Earth by comets.
Source: University of Cardiff
Filed under: Astrobiology, Comets
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July 30th, 2009 at 1:00 pm
1 million years, that's a *very* short time for life to evolve, even bacterial.
July 30th, 2009 at 1:36 pm
We've already flown by and into comets with no reports of microbes. Chasing a billion comets is not the way to go. The way to confirm any of the panspermia or transpermia concepts is to look for and find life on Mars, then compare the genetics. It seems obvious to me that at least one of the transpermia theories is true, and therefore Mars almost certainly has life. The few pathetic, meager efforts to find life on Mars – what will certainly be the greatest discovery in the history of science – speaks volumes. If Dr. Wickramasinghe really believes life is spread everywhere by comets, he should be very outspoken about the lack of an aggresive effort to find it on Mars.
The harm that might be done by a returned microbe from Mars is a risk, but the harm that is being done by this slow "scientific" effort will someday tear society apart.
July 30th, 2009 at 3:10 pm
Yeah… unless we throw billions at looking for life on Mars RIGHT NOW, society will be torn apart. Suuuure….
July 30th, 2009 at 4:24 pm
OK, maybe I was a bit overly dramatic. But I do think, that, IF, for example, some scientists decided to delay the public discovery of life on Mars, even for good reasons, that over time it might have a fairly dramatic societal effect. Something similar to what happened in the "Stanford Prison" experiment, only here, the "Guards" know the secret, and the public does not. The "Guards" become arrogant, cruel, obsessed with their own power, and eventually see the public as an inhuman nuissance. IF the knowledge of life on Mars is being kept secret, I think the scenario I described is not merely a risk, it is inevitable.
July 30th, 2009 at 6:54 pm
TD: wait… so you think that NASA is purposely holding back from discovering life on mars, or that they already have and won't tell us? And that one day they will start treating us inhumanely because of it?
what?
July 30th, 2009 at 7:32 pm
well as i know Chandra Wickramasinghe is the first to tell about organic composition of comets. Sub surface oceans are a new idea of his.
July 30th, 2009 at 7:49 pm
TD,
Which comet probes had the capacity to detect life on comets?
July 30th, 2009 at 8:03 pm
I don't think NASA is withholding information… intentionally.
Its a difficult thing to build a machine that crosses millions of miles through space, takes samples from its somewhat random landing zone, and jackpots identifiable life.
Assuming it doesn't break along the way and make a new crater, its very likely to send back inconclusive signals even if there's something moving in the bucket.
If you want conclusive results, you need to send scientists and their equipment. Otherwise even the proper readings from a probe can be dismissed as sensor errors simply because we don't know what we're looking for.
That being what it is, searching the more habitable planets that have been dusted with the same ice as earth might be more fruitful (and easier) than chasing comets.
July 31st, 2009 at 12:57 am
Well, it makes more sense to me that life developed here on earth. Doesn't mean that water from comets wasn't useful. Maybe, life can develop on both. If it developed on comet, why not on earth?
July 31st, 2009 at 4:03 am
i may be ridiculed for saying this but there is no way that nasa would hold back news of discovery of life on mars.
too many independant thinkers, too much budget potential, too much positive PR potential, the list goes on… but it comes down to the main fact that people wouldn't be able to keep their mouths shut about it.
July 31st, 2009 at 8:11 am
A million years is not much time for life to develop from simple organic substances, especially at the frigid temperatures of comets. If transpermia holds, then any life found anywhere other then Earth would probably tell the tale. The chirality of the amino acids comprising alien proteins would be a dead give-away and it's a relatively simple experiment.
July 31st, 2009 at 8:58 am
Transpermia is likely a minor process, as young planets in the habitable or tidal heating zone are eminent environments for abiogenesis and abiogenesis itself seems so easy. It seems to me much like vertical gene transfer in that regards, something that was originally hailed as likewise important but seems today to be a minor player AFAIU (at the percentage level or lower).
Wickramasinghe is of course riding on the work stemming from the crackpot period of Hoyle, were he entertained creationist ideas and most famously the model error of the "junkyard". [In fact, I just heard that he held to steady state cosmology to the very end, despite the evidence against, in true crackpot fashion.] It doesn't seem to concern him that ~ 1 million year is way to short compared to the accretion and crust formation times of the planets. Maybe Earth itself was faster, I've seen ~ 50 My mentioned, but at least Mars was mentioned at ~ 100 My (IIRC from Mars meteorite evidence) recently. That potential frozen life would be fertile after such long times is an unproven stretch to say the least. Current record seems to be 1.2 My.
Why? I think it was Miller himself who put an upper limit on sea life formation time to 13 ky. (On account of the average time it takes for sea water to become sterilized in heat vents.) And AFAIU calculated that his then prefered model of ice-thaw cycles would satisfy the condition.
[Note that stationary abiogenesis spots, such as the hydrothermal vent theory, don't labor under that condition.]
Any form of bacteria is much different from first life.
Considering the difficulties to reach deep divergencies with any sort of resolution, I think it's unlikely. And even so it would be very difficult to distinguish between non-transpermia, Earth-Mars transpermia or vice versa, or an earlier shared cometary origin, or a few or all of the later.
Btw, I don't think chirality will tell much, as we don't know if foreign life will be chiral or even if early life was. When a genetic system evolves to interact with metabolism it is beneficial but not strictly necessary. One could imagine having doubled genetic systems. Same goes for metabolic systems as such.
[Even today everything from bacteria to eykaryotes have enzymes that takes compounds from one chirality to the other, so in that regard there is "doubled metabolic and genetic systems". Sometimes probably to rectify inevitable spontaneous chirality change so metabolism can work on it. Sometimes specifically to produce the reverse chirality as it has other biological function. Apparently we each have a bunch of reverse chirality compounds. AFAIU this field has exploded in medicine since ~ 2000.]
July 31st, 2009 at 9:10 am
A lot of scientists probably. Unless you can find readily available fossils or evidence for life, such as Mars methane isotope ratios, the usual rate of find will likely apply. And I seem to remember a paleontologist complain that the likelihood that any one of them actually find a fossil in his lifetime was less than 1.
If that is correct we have to prepare to sink at least ~ 30 man-years, or more probably hundreds of them, on the first fossil alone, not mentioning the likely necessary repeats to make sure. I think we have a reason why a longtime Mars outpost would be a good idea.
July 31st, 2009 at 1:00 pm
So, if either Dr. Wickramasinghe's theory of comets spewing water and microbial life, or the theory by Dr. Svante Arrhenius of the uplift of charged spores and then distribution thru space (by the Arrhenius or [self-censored] method) are correct, then maybe some spores came to be encased in ice in the permanent shadows of our moon. If that is true, then LCROSS could conceivably encounter some organics in the plume it will create this October.
Please don't tell me that LCROSS would be unable to detect organics even if they were present. 80 Million dollars just for a single shot detect only water?….can't be.
July 31st, 2009 at 1:15 pm
As for which comet probe could detect life – I would think that if the Stardust aerogel had enountered micron-scale spores, that the organic traces of the impacts in the aerogel would be unmistakeble.
It would be mind-numbingly short sighted if we spent hundreds of millions to go to a comet, collect dust from it and from space at large, return it to Earth, and not be at least technically able to confirm a theory by a Nobel prize winner (Dr. Svante Arrhenius) that spores should be found in space.
July 31st, 2009 at 1:43 pm
Totally forgot about Stardust! Well we haven't heard anything about spores from the Stardust samples.