Intro and abstract of the Hoover paper on bacteria in meteorites
https://journalofcosmology.com/Life100.html
[The entire article is available at the Journal of Cosmology website. Numerous fascinating photographs. This appears to be the real thing.]
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.
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.
Official 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.
Abstract
Environmental (ESEM) and Field Emission Scanning Electron Microscopy (FESEM) investigations of the internal surfaces of the CI1 Carbonaceous Meteorites have yielded images of large complex filaments. 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). Energy dispersive X-ray Spectroscopy (EDS) studies indicate that the meteorite filaments are typically carbon rich sheaths infilled with magnesium sulfate and other minerals characteristic of the CI1 carbonaceous meteorites. The size, structure, detailed morphological characteristics and chemical compositions of the meteorite filaments are not consistent with known species of minerals. The nitrogen content of the meteorite filaments are almost always below the detection limit of the EDS detector. EDS analysis of terrestrial minerals and biological materials (e.g., fibrous epsomite, filamentous cyanobacteria; mummy and mammoth hair/tissues, and fossils of cyanobacteria, trilobites, insects in amber) indicate that nitrogen remains detectable in biological materials for thousands of years but is undetectable in the ancient fossils. 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. Keywords: Origins of life, CI1 meteorites, Orgueil, Alais Ivuna, microfossils, cyanobacteria, comets, Europa, Enceladus
Re: Intro and abstract of the Hoover paper on bacteria in meteorites
I'm a geologist, so my comments come at this from that perspective. If there ever is a meteorite type likely to preserve extra-terrestrial life, it is the CI1 carbonaceous chondrites described in the article. They are micro-breccias thought to be regolith (in this case, material weathered by water) from the surface of the parent body – probably an asteroid or comet judging by the D/H ratios. These extremely rare meteorites crumble to dust when they get wet because their microscopic particles are held together with clay and water-soluble minerals. You need to collect them right after they fall or they disaggregate. Only 5 falls have been directly observed, Orgueil in 1864 being the biggest (4 others were found in Antarctica by the Japanese). Hoover looked at 4 samples, 3 from Orgueil, one from Ivuna, the namesake for the type.
The CI1s are soft enough to be cut with a knife, and early observers described them as humus- or bitumen-like. They are highly carbonaceous and contain complex organic compounds such as kerogen, long-chain fatty acids, protein amino acids, and the breakdown products of chlorophyll. The microscopic filaments exposed on fresh surfaces look very much like bacteria and certainly are not biological contaminants because they lack nitrogen, as do multi-million year old fossils from Earth.
My principal doubts concern the location of the parent body(s) in the Solar System. It is, to say the least, cold in the asteroid belt. If life appeared on a comet, it must have happened quickly, given their perturbable orbits. Big question. Panspermia anyone?
Hoover has taken a lot of flack for this, but before commenting disparagingly, at least RTFA.
Re: Intro and abstract of the Hoover paper on bacteria in meteorites
Quote:
Posted in reply to the post by geomancer:
Hoover has taken a lot of flack for this, but before commenting disparagingly, at least RTFA.
Words to live by.
I read the article, (well, OK, I skimmed some of the denser and less interesting parts) and, keeping in mind that I'm not remotely qualified to judge this stuff, it sure seemed convincing to me. In fact, I'm getting pretty excited about this. It may really turn out to be the first solid evidence of extraterrestrial life (not to mention panspermia), and the connections Hoover makes to sites like Europa are pretty exciting too. Woohoo!
