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Started by Grinning_Colossus, March 05, 2011, 06:15:03 PM

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Grinning_Colossus

Tantalizing  :hmm:

QuoteAre there traces of ancient bacteria trapped inside meteorites that fell to Earth decades ago? You can add that question to the list of unresolved issues surrounding the search for life beyond Earth, thanks to a just-published study by a NASA researcher.
The new study, published in the Journal of Cosmology, focuses on structures that look like the filaments that biologists typically see on micro-organisms known as cyanobacteria. Richard Hoover, an astrobiologist at NASA's Marshall Space Flight Center in Alabama, found the filamentary structures inside samples of meteorites that are thought to date back to the solar system's beginnings, more than 4 billion years ago.
If the structures are confirmed to be of biological but unearthly origin, that would serve as fresh evidence that life can make its way through outer space and "seed" planets, including our own, Hoover told me today.
"Life may have a wider planetary distribution than simply being limited to the planet Earth," he said. In the paper, Hoover said the evidence suggests that microbial life could well exist on comets or icy worlds such as Europa or Enceladus.
Most astrobiologists might be willing to go along with that broad conclusion. However, Hoover's specific claims could well end up in the same sort of limbo that surrounds the claims made 15 years ago about microfossils inside a meteorite from Mars.
The initial evidence was the subject of dramatic news conferences and huge headlines, but as time went on, doubts about the findings grew. Today, few astrobiologists see the Mars meteorite as containing any conclusive evidence for the existence of past or present Martian life.
Cautious and skeptical reactions
"This may turn out to be another one of those cases where it's controversial but remains unproven," Seth Shostak, senior astronomer at the California-based SETI Institute, told me today.
Shostak said Hoover's findings would be "important, if true." But he noted that the research paper relied on a highly technical interpretation of electron microscope images and chemical analyses. "Is it true? I'm not qualified to say that," Shostak said.
The Journal of Cosmology's editor-in-chief, Rudy Schild of the Harvard-Smithsonian Center for Astrophysics, said in a note accompanying Hoover's study that 100 experts were invited to critique the research, and that any commentaries would be published beginning Monday. The overall tone of the commentaries is likely to be skeptical: Lynn Rothschild, an astrobiologist at NASA's Ames Research Center in California, said many biologists were "very concerned" about the claims.
More than one expert wondered why the research merited any news coverage at all.
"Many scientists have examined thousands of meteorites in detail over the past 50 years without finding any evidence of fossil life," David Morrison, senior scientist at the NASA Astrobiology Institute at Ames Research Center, told me in an e-mail. "Further, we know a great deal about the conditions on the parent objects of the meteorites, which (not counting the few meteorites from the moon and Mars) were rather small, not at all like planets.
"I would therefore invoke Carl Sagan's famous advice that extraordinary claims require extraordinary evidence. At a bare minimum this would require publication in a prestigious peer-refereed scientific journal — which this is not. Cyanobacteria on a small airless world sounds like a joke. Perhaps the publication came out too soon; more appropriate would have been on April 1," Morrison said.
Questions about origin
The debate over the validity of Hoover's claims is likely to concentrate over whether the filamentary structures are truly biological in origin, and if so, whether they're the result of earthly contamination.
Hoover said that the filaments, which can measure more than 20 microns long, are of the right size and shape to match the characteristic structures seen in types of cyanobacteria.
"Because of the fact that they are so large and so complex, and many of them have specialized cells, these cyanobacteria can be identified — sometimes to genus and species — just on the basis of certain specialzed cells," he explained. One of the structures found in the meteorites is similar to that seen in the giant bacterium known as Titanospirillum velox, for example.
If the structures are so similar to those seen in earthly organisms, could that be because they're actually the traces of cyanobacteria that found their way into the meteorite? Hoover argues that they're not the result of contamination. He said that cyanobacteria are generally found in aquatic environments, but the meteorites are made of stuff that falls apart when exposed to liquid water. He also said chemical tests on the filaments could find no evidence of nitrogen, which should have been present if earthly cyanobacteria infiltrated the meteorites. One of the meteorites, for example, is known to have fallen to Earth in France in 1864.
"The inability to detect nitrogen in the filaments indicates that they are ancient, and since the meteorite came to Earth in 1864, that indicates that they were in the meteorite when it fell," Hoover said.
Previous analyses of the meteorites' chemical composition have concluded that they were formed during the solar system's earliest epoch, perhaps as comets. But Hoover said that doesn't necessarily mean the structures were present from the very beginning. They could have been picked up from debris that was knocked into space by cosmic impacts. They could even have come from Earth itself, as the result of a meteor blast that occurred millions or billions of years ago.
"That's absolutely possible," Hoover acknowledged. "I have no reason to say I could rule that out."
Hoover has made provocative claims before, and he fully expects that others will contest his conclusions this time as well. "I can only make my observations, based on the scientific results that I see," he told me.
What do you think? Is this a significant advance for the study of life beyond Earth, or a blip hardly worth writing about? Feel free to weigh in with your comments below.
Update for 6 p.m. ET: Rocco Mancinelli, senior research scientist at the Bay Area Environmental Research Institute, weighed in with this e-mailed critique of Hoover's paper:
"As a microbiologist who has looked at thousands of microbes through a microscope, and done some of my own electron microscopy, I see no convincing evidence that these particles are of biological origin. 
"The techniques used may not have been appropriate for these types of analyses. It is stated that the implements were flame-sterilized, with no details of how this was performed.  Were the implements placed in the flame of a Bunsen burner? If so, sometimes soot can get on them at the microscopic level. The usual procedure for flame sterilization is to dip the implements in ethanol then burn the ethanol off. Yet, these would be inappropriate for this type of analysis. You need to have everything clean and then bake at 550 degrees C overnight.  These missing details would cause me to question not just about the photos, but the elemental analyses as well.  I am also disturbed about the lack of nitrogen. There should be more. There are many technical flaws in this paper."

http://cosmiclog.msnbc.msn.com/_news/2011/03/05/6198177-life-in-meteorites-study-stirs-debate
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Eddie Teach

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Caliga

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Alcibiades

Wait...  What would you know about masculinity, you fucking faggot?  - Overly Autistic Neil


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Darth Wagtaros

Quote from: Caliga on March 05, 2011, 09:51:16 PM
Monstrous.
Least Tim's not posting more Star Trek slash fiction.
PDH!

jimmy olsen

It is far better for the truth to tear my flesh to pieces, then for my soul to wander through darkness in eternal damnation.

Jet: So what kind of woman is she? What's Julia like?
Faye: Ordinary. The kind of beautiful, dangerous ordinary that you just can't leave alone.
Jet: I see.
Faye: Like an angel from the underworld. Or a devil from Paradise.
--------------------------------------------
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Darth Wagtaros

PDH!

jimmy olsen

Anyways, on topic, doesn't seem good.

http://scienceblogs.com/pharyngula/2011/03/did_scientists_discover_bacter.php

QuoteDid scientists discover bacteria in meteorites?

Category: Kooks
Posted on: March 6, 2011 9:44 AM, by PZ Myers

No.

No, no, no. No no no no no no no no.

No, no.

No.

Fox News broke the story, which ought to make one immediately suspicious — it's not an organization noted for scientific acumen. But even worse, the paper claiming the discovery of bacteria fossils in carbonaceous chondrites was published in ... the Journal of Cosmology. I've mentioned Cosmology before — it isn't a real science journal at all, but is the ginned-up website of a small group of crank academics obsessed with the idea of Hoyle and Wickramasinghe that life originated in outer space and simply rained down on Earth. It doesn't exist in print, consists entirely of a crude and ugly website that looks like it was sucked through a wormhole from the 1990s, and publishes lots of empty noise with no substantial editorial restraint. For a while, it seemed to be entirely the domain of a crackpot named Rhawn Joseph who called himself the emeritus professor of something mysteriously called the Brain Research Laboratory, based in the general neighborhood of Northern California (seriously, that was the address: "Northern California"), and self-published all of his pseudo-scientific "publications" on this web site.

It is not an auspicious beginning. Finding credible evidence of extraterrestrial microbes is the kind of thing you'd expect to see published in Science or Nature, but the fact that it found a home on a fringe website that pretends to be a legitimate science journal ought to set off alarms right there.

But could it be that by some clumsy accident of the author, a fabulously insightful, meticulously researched paper could have fallen into the hands of single-minded lunatics who rushed it into 'print'? Sure. And David Icke might someday publish the working plans for a perpetual motion machine in his lizardoid-infested newsletter. We've actually got to look at the claims and not dismiss them because of their location.

So let's look at the paper, Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites: Implications to Life on Comets, Europa, and Enceladus. I think that link will work; I'm not certain, because the "Journal of Cosmology" seems to randomly redirect links to its site to whatever article the editors think is hot right now, and while the article title is given a link on the page, it's to an Amazon page that's flogging a $94 book by the author. Who needs a DOI when you've got a book to sell?

Reading the text, my impression is one of excessive padding. It's a dump of miscellaneous facts about carbonaceous chondrites, not well-honed arguments edited to promote concision or cogency. The figures are annoying; when you skim through them, several will jump out at you as very provocative and looking an awful lot like real bacteria, but then without exception they all turn out to be photos of terrestrial organisms thrown in for reference. The extraterrestrial 'bacteria' all look like random mineral squiggles and bumps on a field full of random squiggles and bumps, and apparently, the authors thought some particular squiggle looked sort of like some photo of a bug. This isn't science, it's pareidolia. They might as well be analyzing Martian satellite photos for pictures that sorta kinda look like artifacts.

The data consists almost entirely of SEM photos of odd globules and filaments on the complex surfaces of crumbled up meteorites, with interspersed SEMs of miscellaneous real bacteria taken from various sources — they seem to be proud of having analyzed flakes of mummy skin and hair from frozen mammoths, but I couldn't see the point at all — do they have cause to think the substrate of a chondrite might have some correspondence to a Siberian Pleistocene mammoth guard hair? I'd be more impressed if they'd surveyed the population of weird little lumps in their rocks and found the kind of consistent morphology in a subset that you'd find in a population of bacteria. Instead, it's a wild collection of one-offs.

There is one other kind of datum in the article: they also analyzed the mineral content of the 'bacteria', and report detailed breakdowns of the constitution of the blobs: there's lots of carbon, magnesium, silicon, and sulfur in there, and virtually no nitrogen. The profiles don't look anything like what you'd expect from organic life on Earth, but then, these are supposedly fossilized specimens from chondrites that congealed out of the gases of the solar nebula billions of years ago. Why would you expect any kind of correspondence?

The extraterrestrial 'bacteria' photos are a pain to browse through, as well, because they are published at a range of different magnifications, and even when they are directly comparing an SEM of one to an SEM of a real bacterium, they can't be bothered to put them at the same scale. Peering at them and mentally tweaking the size, though, one surprising result is that all of their boojums are relatively huge — these would be big critters, more similar in size to eukaryotic cells than E. coli. And all of them preserved so well, not crushed into a smear of carbon, not ruptured and evaporated away, all just sitting there, posing, like a few billion years in a vacuum was a day in the park. Who knew that milling about in a comet for the lifetime of a solar system was such a great preservative?

I'm looking forward to the publication next year of the discovery of an extraterrestrial rabbit in a meteor. While they're at it, they might as well throw in a bigfoot print on the surface and chupacabra coprolite from space. All will be about as convincing as this story.

While they're at it, maybe they should try publishing it in a journal with some reputation for rigorous peer review and expectation that the data will meet certain minimal standards of evidence and professionalism.

Otherwise, this work is garbage. I'm surprised anyone is granting it any credibility at all.

Want more dismissive reviews? Read David Dobbs and Rosie Redfield. We have concensus!
It is far better for the truth to tear my flesh to pieces, then for my soul to wander through darkness in eternal damnation.

Jet: So what kind of woman is she? What's Julia like?
Faye: Ordinary. The kind of beautiful, dangerous ordinary that you just can't leave alone.
Jet: I see.
Faye: Like an angel from the underworld. Or a devil from Paradise.
--------------------------------------------
1 Karma Chameleon point

Ed Anger

Stay Alive...Let the Man Drive

Eddie Teach

Any chance of a story about Uhura and her college roommate? :perv:
To sleep, perchance to dream. But in that sleep of death, what dreams may come?