Evidence of Extraterrestrial Life Discovered?

Posted on March 5, 2011  Comments (1)

Has evidence of extraterrestrial life been discovered? In Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites , Richard B. Hoover, Ph.D. NASA/Marshall Space Flight Center, puts forth his evidence on the discovery of evidence of cyanobacteria in meteorites.

Dr. Hoover has discovered evidence of microfossils similar to Cyanobacteria, in freshly fractured slices of the interior surfaces of the Alais, Ivuna, and Orgueil CI1 carbonaceous meteorites. Based on Field Emission Scanning Electron Microscopy (FESEM) and other measures, Dr. Hoover has concluded they are indigenous to these meteors and are similar to trichomic cyanobacteria and other trichomic prokaryotes such as filamentous sulfur bacteria. He concludes these fossilized bacteria are not Earthly contaminants but are the fossilized remains of living organisms which lived in the parent bodies of these meteors, e.g. comets, moons, and other astral bodies. The implications are that life is everywhere, and that life on Earth may have come from other planets.

The importance of this claim is hard to ignore. The journal includes a statement from Dr. Rudy Schild, Center for Astrophysics, Harvard-Smithsonian, Editor-in-Chief, Journal of Cosmology:

Dr. Richard Hoover is a highly respected scientist and astrobiologist with a prestigious record of accomplishment at NASA. Given the controversial nature of his discovery, we have invited 100 experts and have issued a general invitation to over 5000 scientists from the scientific community to review the paper and to offer their critical analysis. Our intention is to publish the commentaries, both pro and con, alongside Dr. Hoover’s paper. In this way, the paper will have received a thorough vetting, and all points of view can be presented. No other paper in the history of science has undergone such a thorough analysis, and no other scientific journal in the history of science has made such a profoundly important paper available to the scientific community, for comment, before it is published. We believe the best way to advance science, is to promote debate and discussion.

Read the full paper.

The filaments have been observed to be embedded in freshly fractured internal surfaces of the stones. They exhibit features (e.g., the size and size ranges of the internal cells and their location and arrangement within sheaths) that are diagnostic of known genera and species of trichomic cyanobacteria and other trichomic prokaryotes such as the filamentous sulfur bacteria. ESEM and FESEM studies of living and fossil cyanobacteria show similar features in uniseriate and multiseriate, branched or unbranched, isodiametric or tapered, polarized or unpolarized filaments with trichomes encased within thin or thick external sheaths. Filaments found in the CI1 meteorites have also been detected that exhibit structures consistent with the specialized cells and structures used by cyanobacteria for reproduction (baeocytes, akinetes and hormogonia), nitrogen fixation (basal, intercalary or apical heterocysts) and attachment or motility (fimbriae).

These studies have led to the conclusion that the filaments found in the CI1 carbonaceous meteorites are indigenous fossils rather than modern terrestrial biological contaminants that entered the meteorites after arrival on Earth. The δ13C and D/H content of amino acids and other organics found in these stones are shown to be consistent with the interpretation that comets represent the parent bodies of the CI1 carbonaceous meteorites. The implications of the detection of fossils of cyanobacteria in the CI1 meteorites to the possibility of life on comets, Europa and Enceladus are discussed.

Has life been found in a meteorite? by Phil Plait

Clearly, Hoover thinks terrestrial contamination is unlikely. However, 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; I’d like to see other biologists examining the original meteorite, too.

So, to conclude: a claim has been made about micro-fossils in a meteorite. The claims are interesting, the pictures intriguing, but we are a long, long way from knowing whether the claim is valid or not! We’ve been down this road before and been disappointed.

Analysis by Ian O’Neill

Well, we’ve been here before, and the past claims of alien life discoveries (whether it be in a meteorite sample or on the Martian surface) have been notoriously difficult to confirm. Also, this isn’t the first time Hoover has announced such discoveries. I think there will be a far more measured response to this new research, and it will probably take years and dozens of follow-up studies to confirm or deny this extraordinary claim.

Is this claim of bacteria in a meteorite any better than the 1996 one? by Rosie Redfield

Bottom line: The Ivuna meteorite sample showed a couple of micron-scale squiggles, one of which contained about 2.5-fold more carbon than the background. One of the five Orguil samples had at least one patch of clustered fibers; these contained more sulfur and magnesium than the background, and less silicon. As evidence for life this is pathetic, no better than that presented by McKay’s group for the ALH84001 Martian meteorite in 1996.

One Response to “Evidence of Extraterrestrial Life Discovered?”

  1. Anonymous
    March 21st, 2011 @ 1:52 pm

    I think doctor Hoover is right, and im also sure that these fossilized bacteria are fossilized stuff of living organisms . We must be aware that life is everywhere no only on our planet..

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