In an article appearing in the March issue of the Journal of Cosmology, Richard B. Hoover, a NASA engineer at the Marshall Space Flight Center, announced that he had he had discovered structures in a number of meteorites that he believes are the remains of microscopic life.
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.
This article has generated considerable interest in the media and Dr. Hoover's ideas have been widely aired. However, there are a number of reasons to treat this claim with considerable skepticism.
The structures in question are not complete, definitive casts of microorganisms. They are simple filamentous (hair-like) forms of very short length. Very similar forms can be generated through processes that have no relation with life processes. Some of the structures found in the meteorite may display striking similarities to shapes found in parts of terrestrial bacteria. This should not be surprising. Terrestrial bacteria come in so many shapes, that it is possible to find a match for almost any fibrous form. This is particularly true if you ignore scale, as Hoover has done in using photos to suggest similarity in structures that are an order of magnitude smaller than their supposed terrestrial equivalents.
Chemical analysis does not indicate similarity to terrestrial organisms. The analysis of the filament structures does not indicate the levels of nitrogen or phosphorus that would be found in bacterial remains. In addition, Hoover has made multiple claims about the difference in chemical profile between the filaments and surrounding material which do not appear to be supported by the data provided. The mismatch between the chemical profile of these filaments and analysis of terrestrial bacteria might be explained if the structures had been replaced through permineralization, but such replacement would almost certainly destroy just the type of very tiny structures in these filaments that Hoover claims to have detected. The chemical evidence presented only increases the likelihood that any visual similarity to structures in terrestrial organisms is coincidental.
The resolution of this data invites subjective interpretation. Partial structures of only a few micrometers in size are being interpreted against material composed mostly of particles that are of the same order of magnitude. The interpretation of fine structure being made appears to be unsupported by the resolution of the available data. At this scale, even preservation by permineralization would make it difficult to authoritatively determine that these structures originated in living organisms.
The Journal of Cosmology is not a respected, peer-reviewed journal. Though Dr. Hoover says he has made his article available to a large number of scientists for review, this is a far cry from saying these scientists have reviewed the article in advance of publication. In fact, it's unclear whether the article has gone through any review at all. The Journal of Cosmology is a website with strong leanings toward the idea that life originated in space, not a neutral scientific publication. Publication at this site should not be viewed as carrying the weight of traditional scientific review. In fact, the Journal of Cosmology has announced that it is going out of business in a press release filled with strange assertions of persecution from NASA. In short, choosing this site for publication detracts from the credibility of the article.
This work does not carry the imprimatur of NASA. Though Dr. Hoover works at a NASA facility, and cites NASA employees in his article, NASA has not endorsed his statements. It is unclear if NASA was aware of Dr. Hoover's work, whether he had permission to publish this paper, or whether the article was subject to any review at NASA. There is genuine concern from researchers at NASA that this story is getting unwarranted attention. There is even some question as to whether Dr. Hoover is actually Dr. Hoover. In any case, his position at NASA is as an engineer, and this type of microbiology research does not appear to be in the scope of either his training or the work he does for NASA. It is certainly possible for outsiders in a field to bring fresh insight. Alfred Wegener, who overturned many ideas in geology with the theory of plate tectonics, was a meteorologist. Physicist Luis Alvarez was the first to offer proof that extinction events on Earth were related to impacts from space. It is not necessary to have a Ph. D. in a field to do groundbreaking work. However, the assertion in the Journal of Cosmology that Dr. Hoover is an "astrobiologist with a prestigious record of accomplishment at NASA" certainly suggests an intent to obscure Dr. Hoover's background and provide false authority.
Dr. Hoover's article is far from the first such assertion. Structures sometimes considered to be potential microfossils have been found in meteorites of various types, and have been put forward by papers going back at least to 1961. Similar claims were made in 2005 about tiny structures found in a meteorite which originated on Mars. However, evaluations of these claims by many researchers over the decades has concluded that the structures in question are either not the result of life processes or are too poorly preserved to make any judgment.
The article itself contains a good deal of extraneous material not pertinent to question of whether these remains are from living organisms. While Dr. Hoover may be attempting to give a broad view of the history of meteorite falls and other related material, the impression generated is of an article that has very little new data to relate. Certainly not the level of data needed to sustain the principle assertion.
What's shown in this article are some worm-shaped forms that appear similar to partial structures on terrestrial organisms. However, nothing in the article shows this similarity to be more than superficial, a conclusion backed up by the chemical analysis. The Journal of Cosmology is not a scientific journal, but a web site dedicated promoting the idea that life originated in space (and to selling related books). Dr. Hoover does not appear to be a biologist with expertise in this area as presented in materials at that site.
It would be very exciting to discover definitive proof of extraterrestrial life, even if that life is restricted to the simplest possible forms. However, the claims put forward in this article go well beyond the supporting data and seem better designed to draw attention than to provide information.
UPDATE NASA has released a statement on Dr. Hoover's article.
NASA cannot stand behind or support a scientific claim unless it has been peer-reviewed or thoroughly examined by other qualified experts. This paper was submitted in 2007 to the International Journal of Astrobiology. However, the peer review process was not completed for that submission. NASA also was unaware of the recent submission of the paper to the Journal of Cosmology or of the paper's subsequent publication.
Updated by mem from somerville at Mon Mar 7, 2011, 04:40:37 PM
In a BBC interview this morning, the editor of the Intl. Journal of Astrobiology said that not only was it submitted, it was rejected with the advice that it would make the journal look bad to publish it. I am unable to locate the audio for this interview yet, but will keep looking. --mem from somerville [can I really update other people's diaries??]
Updated by mem from somerville at Mon Mar 7, 2011, 04:44:13 PM
Apparently I can update... Anyway, here's the guy who said it:
@totalastronomy Simon Mitton
Hoover Alien fossil life in meteorite. Here me debunk 1232 GMT today on BBC World Service. Am available to news media seeking rebuttal
Updated by mem from somerville at Mon Mar 7, 2011, 06:56:45 PM
Found the audio clip, BBC Newshour: http://www.bbc.co.uk/...
Dr Simon Mitton, Astronomer Cambridge Univ, Editor of Intl J of Astrobiology: "Because I saw an earlier version of this paper 4 years ago....It was submitted to the International Journal of Astrobiology, and we did the normal course of events when papers are submitted. We sent it out for review to experts, in this case microbiologists, and we were advised not to publish that version of the paper because it would have seriously harmed the standing of our journal."
emphasis mine