Alien Life Info, But Not Status, Found


A new Journal of Cosmology article says that sealed deep in the water-clay-full sort of (CI1 carbonaceous) meteorites that likely come from comets, one consistently finds forms that look visually and chemically like ancient bacteria fossils. Typical reactions:

This effort clearly falls into the category of “extraordinary claims” that require extraordinary evidence. (more)

Dr David Marais, an astrobiologist with NASA’s AMES Research Centre, said he was very cautious about jumping on the bandwagon. These kinds of claims have been made before, he noted and found to be false. “It’s an extraordinary claim, and thus I’ll need extraordinary evidence,” he said. (more)

Those are odd and intriguing formations, to be sure. … Contamination, no matter how unlikely, is a more mundane explanation than extraterrestrial life, and Occam’s Razor will always shave very closely here. We have to be very, very clear that contamination was impossible before seriously entertaining the idea that these structures are space-borne life. I’ll be honest: my own reaction is one of extreme skepticism. As it should be! All things being equal, I would take news like this with a very large grain of salt, and want a whole lot of outside expert analysis. (more)

The last one links to this explanation:

Extraordinary claims require extraordinary evidence because they usually contradict claims that are backed by extraordinary evidence. The evidence for the extraordinary claim must support the new claim as well as explain why the old claims that are now being abandoned, previously appeared to be correct.

Alas, these attitudes make far more sense in status terms than in information terms.

In status terms, it would of course be big news to hear that academia had declared its consensus that alien life had most likely been found. Academia’s public and patrons would take heed, and the academics associated with inducing that event would gain high status. So academics want to ensure that only folks with quite impressive academic abilities could gain such a prestigious honor. Thus they naturally want to that this honor goes to folks with extremely impressive data, methods, etc. And this paper, published in a low prestige journal by a low prestige academic, using solid but not especially difficult techniques, seems below that bar.

But in information terms, this new result does seem in the ballpark of tipping us over the threshold of thinking it likely than alien life has been found.

First, our prior estimate that alien life would be found in comet-based meteorites should have been pretty high. The idea that life came here from out there is a standard reasonable view:

Panspermia is no longer a marginalized view. It may not yet be the majority opinion, but it shows up often in journal articles and conference proceedings.

Counting by volume, comets seem the most likely place to find such life, and so meteorites from comets would be the most likely place to find alien fossils. We also seem to see alien fossils from Mars. Furthermore, the only known betting market on this topic has for 15 years consistently said we’d find evidence of alien life by 2050:


Not only should our prior on finding alien life in comets be high, the likelihood of this new data seems much higher if alien comet life were common than if it didn’t exist. This new data was was careful to examine only opened surfaces in a sterile vacuum:

The study was confined to investigations of uncoated, freshly fractured, interior surfaces of the meteorites. All tools, sample holders and stubs were flame sterilized. Lunar dust samples and silicon wafers were used as negative controls. … The meteorites were stored in sealed vials at -80 oC and after preparation, electron microscopy stubs were kept in sealed containers in dessicator cabinets or in the freezer. The fusion crust and old cracks in the stones were carefully avoided. The meteorite samples were placed in the instrument chamber (with the fresh fracture surface up) a pumped down immediately after the stones were fractured. All solvents, acids or other liquids were strictly avoided. … Only one seriously Murchison sample was found to be contaminated with fungal filaments (in old cracks in the fusion crust) and not a single pollen grain has been encountered during extensive studies of carbonaceous meteorites carried out since 1996 at the NASA/Marshall Space Flight Center.

Furthermore, the chemical signatures found match ancient fossils far better than recent life. And how could meteorites that fell to Earth a century ago get contaminated with ancient Earth fossils?  Yes these forms might have non-biological explanations, but the point is the likelihood ratio – that such forms that look much like known life are much more likely given life than given not.

Informationally, a nearly neutral prior together with a strong new likelihood ratio should have us now accepting the claim as more likely than not. But academia will not publicly admit that fact until they can find a status holder to credit who they consider worthy of the honor. The journal says:

Members of the Scientific community were invited to analyze the results and to write critical commentaries or to speculate about the implications. These commentaries will be published on March 7 through March 10, 2011.

I’d bet these commentaries will mostly say this is interesting but doubts remain, that this evidence is too ordinary to support its “extraordinary” conclusion, and yet they’ll refuse to bet on the subject. How sad is that?

Added 2:30p: This claims Ladbrokes offers 1000 to one odds against finding alien life, but I can’t find more details online. This says William Hill offers 100 to one odds against “proof of the existence of intelligent extra-terrestrial life will be provided within a year”, but there’s no word on longer time scales.  PaddyPower‘s odds estimate a <20% chance “The sitting President of the USA making a statement confirming without doubt the existence of alternative life beings from another planet” after 2020, and a <30% chance for before 2020 (including a 2.5% chance for 2011).  An Intrade offer of 5% for a NASA announcement by 2013 also implies ~2.5%/year.

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  • Robert Koslover

    Yes, I think you are effectively revealing an extension to the rule that “extraordinary claims require extraordinary evidence,” to the effect that “fame-making discoveries by ordinary people call for great skepticism.” And… I assert that this is, for the most part, just as it should be! And why, you may ask? Because fame, just like money and power, is terribly seductive and corrupting. People are often willing to deceive both themselves and others in their quests for great fame, great money, and/or great power. So we are correct to be wary of them and to demand extraordinary evidence. We are also correct to be at least somewhat less wary of already famous/successful prior experts (at least, if we believe their prior fame was justified!) because they already have a successful track record, and it is thus less obvious that they might be deceiving themselves and/or us.

  • I have seen the “extraordinary claims” bit mostly in response to psi and similar pseudoscience that was contradicting well-established science. That is not the case here, as you point out, and that requirement for “extraordinary evidence” should not be being made. On the other hand, skepticism is warranted, this is only the first paper/study on this, and many, many papers and studies are wrong. It wasn’t that long ago that the claims about finding micro-fossils in Martian meteorites was current, and more recently the quickly disproven claims about arsenic replacing phosphorus in some microbes metabolic pathways. Until this is replicated, it is interesting but quite possibly wrong.

    For anyone seriously interested in how science goes wrong, read Gary Taubes’s mammoth book Bad Science about the Cold Fusion fiasco.

  • SteveH

    I’m open to life probably not being confined to earth. But we have to concede the universe is unbelievably vast and in no way kind to life’s existence. Much less its existence on a scale that allows us to find evidence of it at our wayward outpost, bordering on odds that seem ridiculously astronomical. Pun intended.

  • Aron

    So basically there’s a million dollar bill lying on the ground.

  • nate

    I’m not so sure I buy the status argument in this instance. Often some of the most famous and prestigious scientists in a field will make claims that aren’t at all accepted by the scientific community. Roger Penrose’s views on consciousness and quantum mechanics, Arthur Eddington’s numerology-like attempts to reduce physics to pure numbers, and even Einstein’s quest to unify QM and GR, all the while ignoring 2 (the strong and weak forces) of the 4 forces of nature are all examples off the top of my head of scientists of the highest status whose ideas were overwhelmingly shunned by other scientists (and for good reason).

  • Andy McKenzie

    Robin, what is it going to take to get sites like the one you linked to to use real money? This seems like a really important problem.

    • Kevin Nicholas

      A change in the law, probably. Gambling is illegal.

  • Matthew Fuller

    Cool, so if alien life odds are high, than the odds of of intelligent design have to have gone up, if only a smidgen. If intelligent aliens were discovered then the odds of us being designed by aliens has gone up again. If the aliens say their are billions of other species of aliens, all more advanced than us (so advanced we cannot find them) then the odds of of ID goes up again…

    unless you don’t like being designed by aliens. The status argument seems to explain too much. Saying as such could also be a status move.

  • Matthew C.

    I have seen the “extraordinary claims” bit mostly in response to psi and similar pseudoscience that was contradicting well-established science.

    This sentence is completely off base. Psi absolutely does not “contradict well-established science”. “Pseudoscience” is best used to describe the behavior of people who make up their minds about a topic without investigating the evidence.

    Bill, I bet you haven’t even read one single book about psi research from a non-scoffer cover to cover.

    If I am correct in this guess, basically, your entire opinion on psi is based on the opposition of your sociological peer group. Which is of course exactly why people have religious beliefs and follow the pope.

    • Constant

      I read many books on it. The lack of evidence for it ultimately overwhelmed me. The one book that I specifically remember is that one by the Stanford physicists who were taken in by Geller, Mind Reach by Targ and Puthoff, originally published 1978. It was from that book that I learned the lesson that physicists are as ill-equipped to deal with charlatans as anybody. Magicians like Houdini and Randi, whose profession requires thorough mastery of the art of deception, are much better equipped to unmask charlatans, though props must be given to Emily Rosa for her unmasking of Therapeutic Touch.

  • Tor
    • Chris T

      Not surprising, Hanson seems to have a pretty big emotional desire (bias) for panspermia to be true. This, ironically, shows why these types of claims require extraordinary evidence.

      • Erisiantaoist

        Really? I’d think with the Great Filter implications of panspermia, he’d very much want it not to be true.

    • fructose

      Yeah, a blog post that starts of with a bunch of ad-homs is conclusive. Cue eye-roll.

  • So how much are you willing to bet at what odds for it? I’m sure you’ll find some respectable academic willing to take the other side, and you’ll win considerable amount of money and status this way if you’re right and everybody else is wrong.

  • Chris T

    ‘Extraordinary evidence’ is warranted with claims of extraterrestrial life. Any scientist who shows its existence definitively will ensure his/her place in the history books. There is also a great degree of wish fulfillment involved and thus the potential for self-delusion is high. All claims should be equal, but throw in human bias and they’re not.

    I’d bet these commentaries will mostly say this is interesting but doubts remain, that this evidence is too ordinary to support its “extraordinary” conclusion, and yet they’ll refuse to bet on the subject.

    Give scientists with direct control of the outcome a financial stake in it? That sounds like a great idea!

  • Robert, a great many non-famous people, like you, also have successful track records.
    bill, yes many papers are wrong, but those Martian life claims still seem valid.
    Aron, do tell me where this money lies.
    ante, yes many prestigious folks make contrarian claims. How did I suggest otherwise?
    Andy, see anti-gambling law.
    Tor, that author mainly complains about the paper’s formatting.
    Tomasz, I’ll let others make the first offers, but I’ve got $1000 I’m willing to commit here.
    Chris, very few scientists have direct control of this outcome.

  • DK

    Tomasz, I’ll let others make the first offers, but I’ve got $1000 I’m willing to commit here.

    Sounds like easy money. I am interested. Precise conditions?

  • The important information is the chemical signature – that we are seeing asymmetric amino acids in ratios and amounts typical of fossils. This can have no other explanation than life, ancient fossils that were once alive, a very long time ago. While contamination with today’s earthly living organisms is very likely, contamination with earthly ancient fossils is very unlikely.

  • Wophugus

    Tor, that author mainly complains about the paper’s formatting.

    He has several valid reasons for thinking the paper is bullshit: 1. The supposed bacteria are quite large, looking more like life after it had evolved a bit on earth than life at its origin. 2. The “bacteria” they found are dispersed and lack a consistent morphology. Bacteria rarely live alone, they usually live in cultures. It would be odd to find a few different species of a single bacteria hanging out on its own in a bunch of rocks. 3. The Surface of these meteorites is extremely fractured, and it seems entirely possible that little holes that look kind of like bacteria if you squint right would appear. 4. The mineral content of the bacteria don’t match the profile you would expect for life.

    • I see little reason to expect ancient comet bacteria to be more the size of early than later Earth bacteria. I see a lot of similar shapes nearby in those images. The mineral content matches ancient fossils much better than recent life – that is the point!

      • LeBleu

        No offense Robin, but I think PZ Myers, a biologist, is more qualified than an economist to evaluate these claims. Also, from my prior experience reading his blog he seems to be reasonable and accurate.

  • Vladimir M.

    So you think that the expert opinion on this issue is fatally biased due to status considerations. But even if there is conclusive evidence that such a bias exists, shouldn’t you nevertheless refrain from forming an opinion about the topic, in the spirit of your recent admonishment against DIY scholarship? Or do you think that unlike the experts suffering from status-related biases, you are “mostly immune from such problems”? (In which case I’d be really curious to see the reasoning that led you to assume that.)

    • Carl Shulman


    • Chris T

      Fourthed. This area seems to be one of Robin’s blindspots.

    • Khoth

      I think there’s a simple explanation: Robin’s a contrarian – he’s not trying to maximise the probability of being right, he’s trying to maximise the probability of supporting something unlikely-seeming that turns out to be right.

  • Rafal Smigrodzki

    Robin, maybe you would dismiss this as “near-thinking” but if you look at the history of a comet-derived meteorite, it’s really hard to imagine it could have ever been exposed to conditions that we know spawned life – warm but not hot undersea alkaline vents. For life as we know it to develop you need a reasonable temperature, protection from ionizing radiation, a stable source of energy – and even assuming that warming during perihelion could in principle provide some circulating water and a source of chemical energy, there would be hundreds of years of cooling, and time to dissipate a lot of the chemical gradients that are needed to jump start life. This is not to say we know enough about the conditions that are indispensable for life to appear – but clearly the physicochemical history of the chondrites is diametrically different from a known location in the configuration space amenable to life, and this is clearly a reason to be somewhat skeptical here. Add to the consideration that if indeed you can have biogenesis inside comets, then, given that comets are the same literally everywhere, there would have to be alien life everywhere as well – and some incredibly efficient mechanism would be needed to explain absence of any other signs in our observations of space. This would make the Fermi paradox so many orders more difficult to explain than assuming biogenesis only on the right kind of planets.

    So, status or no status, I won’t believe in the comet bugs, until somebody finds an alien genetic material (preferably not DNA), and 3 or 4 groups confirm it from different comet samples.


  • There is not a hint of evidence of any life forms coming here from off planet. Every single bit of the DNA evidence from extant organisms that have had their whole genome sequenced looks like all Earth organisms shared a Last Universal Common Ancestor about 2.5+ billion years ago.

    Maybe Earth life is just so much superior to non-Earth life that the non-terrestrial bacteria get eaten up very quickly and then are gone. Or maybe the LUCA for Earth life and bacteria on comets in this solar system is the same, maybe something on Europa.

    I have no doubt that there is life elsewhere, the universe is a big place. I don’t find this evidence compelling at all.

    • The point is that that last common ancestor may have come from space.

  • Rafal Smigrodzki

    More skepticism – I read the article, and I am completely unimpressed. All this talk about “heterocysts” and “trichomes” is bunk – what they see is bumps and wisps which look like known biological structures – but these structures are just bumps and wisps very similar in appearance to various mineralogical formations. We know trichomes are alive because they are formed in living things – but we can’t know if wispy-looking things found in a rock came from an organism, or from an abiogenic source.

    Furthermore, they showed convincingly that the structures are not modern biological contaminants – but then they also failed to show any clear signature of life. Kerogen, purines, amino acids, all these are common abiogenically formed substances. The only interesting finding is the relative preponderance of certain L-aminoacids (but only a few, they don’t break most according to chirality) – this could explain chirality of life on Earth, if terrestrial amino acids were of comet origin, and if there is a chiral process influencing synthesis or breakdown of these few amino acids in comets. However, if the comet aminoacids were all biogenic, then they all would be L enantiomers to a similar extent – so the absence of data on e.g. L-glycine makes me think they are hiding inconvenient findings.

    After reading it, I am even more skeptical than before.


    • DK

      so the absence of data on e.g. L-glycine makes me think they are hiding inconvenient findings.

      After reading it, I am even more skeptical than before.

      Rafal, just FYI: there is no such thing as L-glycine. Glycine is not chiral (its side change is hydrogen) – that is high school biology. Also, the paper reports virtually no nitrogen found. So there are no any amino acids there.

  • Robert Koslover

    Intrade has “NASA to announce discovery of extraterrestrial life before midnight ET 31 Dec 2011” at 10% chance.

  • MichaelG

    Can someone point me to actual evidence of panspermia? It always seemed like a cop-out to me. “We can’t figure out how life originated so quickly on Earth, so perhaps it came from somewhere else!”

    And are you suggesting that this life evolves in comets? And still looks like early Earth life, and looks the same from different comets? Is there only one way for primitive life to turn out? Is there even enough energy available in a comet ecosystem to produce life?

    Plus I thought comets had a similar age to the Earth. If life could evolve there since the formation of the solar system, why not on Earth?

    If that’s the case, it’s not the classic panspermia of the Earth being seeded from elsewhere. Instead, you are claiming that life originates everywhere, even under conditions as diverse as comets vs. undersea vents — and it all comes out looking similar, with similar chemical signatures!

  • David
    • The big evidence is not the odd shapes, but amino acid ratios, which are characteristic of fossilized organic matter. For example:

      The meteorite Ivuna Cl1 contained 372 parts per billion of l glutamic acid, but only 8 parts per billion of d glutamic acid, indicating that that glutamic acid came from living things. That there was glutamic acid but no leucine, as is typical in earthly organic fossils, indicates that those living things died millions or billions of years ago, hence unlikely to be the product of earthly contamination of the meteorite. Finding traces of biological amino acids with what look like fossilized earthly microorganisms is a pretty good indication that these are indeed real fossils

      • david

        1) As far as I can tell, the measurements of amino acid ratios were not performed in this study, but are taken from previous studies from different laboratories. The references and methods are a bit confused, so I can’t be certain of this. Assuming that is the case, these ratios are not associated specifically with the filaments, and have been known for years. I’d add that the odd shapes constitute the bulk of their “results”. Clearly Hoover thought it was important.

        2) As with filament formation, there are known abiotic mechanisms for the synthesis and enantioenrichment of amino acids. The fact that the most prevalent amino acids in the meteorite are things like glycine, AIB and isovaline, all common products of the Miller-Urey synthesis, tends to bolster the case that these are abiotic. Hoover barely mentions let alone offers any evidence to exclude this possibility. I’d also note that there’s a lot of argument over the precise ee measurements in murchison that Hoover ignores. The 96%ee for glu is at the extreme end of the range argued by different investigators.

        The point here isn’t that these meteorites definitely don’t contain life (or its remains); we don’t know. But there are many ways for abiotic mechanisms to produce evidence that an incautious investigator will take to indicate life, thus any paper claiming to have found life but failing to exclude these mechanisms is most likely incorrect.

  • RickG

    The “original” (but unrelated to this one) alien-microbes-in-a-meteorite-paper was published in Science in 1996 (, and the senior author was Dick Zare of Stanford, who was at the time perhaps the most high-status analytical chemist in the world. So if other scientists are waiting to bite on a high-status scientist publishing this kind of work, they already had their chance — 15 years ago. I think the skepticism over the newer work in Journal of Cosmology comes in part from the fact that, well, the title of the paper on the journal website contains a link to a book on Amazon. That’s kind of sketchy.

  • albatross

    Michael G:

    The argument for pamspermia I find plausible is a variant of the Fermi paradox. We know that there are living things on Earth that appear to be capable of living in incredibly hostile-to-us environments, surviving years of hard vacuum and radiation and cold, etc., so we can see that it’s possible for life to move between planets. It’s plausible that it might even sometimes move between stars–at comet speeds, I think you could get from here to the nearest star in under a million years. Now, we don’t know how long it took to get life started on Earth after conditions were right, but if we imagine it takes a billion years to get the stars to align perfectly to get life to arise and survive once you’ve got hospitable conditions for it, life arising once might very well spread out to other stars from occasional glancing blows from meteors, life-bearing planets being smashed to bits and scattered by big collisions, etc., before it can arise locally.

    I think the critical parameters there are, first, what’s the expected time for life to arise independently, and second, what’s the expected time for a life-bearing package to get from life-bearing-planet A to life-ready planet B. As best I can tell, we don’t know enough to have more than a rough guess at either number, but I’m no expert.

    I suspect the main reason why extraordinary evidence is needed for extraterrestrial life is less that it would be a huge scientific coup (though that’s clearly an issue), but that it would shake up so many peoples’ worldview in such big ways.

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  • Robert Koslover

    This doesn’t provide encouragement to those hoping this discovery would be substantiated.

    • DK

      I am pretty sure that the whole thing is BS but it is still disappointing to see that a large portion of the criticism deals with the author’s and journal’s credentials instead of the actual data.

  • some guy

    go to link

    in all reality there is like a 99.99% that this claim is wrong, but Hoover is not stupid, despite what other condescending critics say, most have a very limited knowledge of his past.

    if u cared to read the article, this guy has identified three undiscovered bacteria. To argue that he misidentified a mineral build up for a life form is wouldn’t add up with his reputation so far.

    2ndly how can u get anyone credible to back his claim when the life he discovered does not contain nitrogen, like really. Im assuming the way he introduced it to the public was a last resort.

    Im sure Hoover is biased as hell, but he knows what hes doing. Everyone who has been a skeptic in the post has made the logical decision. but dismissing it as already wrong with such little information is ignorance.

  • some guy

    ps. this has obvious grammatical errors, my b.

    but props to you Hanson, your articles are a fun read.

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