If you have a pulse and care about such things, you no doubt have heard about the alleged claim of proof for alien life forms put forth by NASA scientist Richard Hoover in a recent journal article. The picture below purports to be a fossilized bacterium from a rare meteor. I naturally have some thoughts.
For starters, it’s a bit surprising, perhaps even suspicious, that there was no huge press conference for this, as was the case with the arseno-DNA event that was roundly criticized within the science community (kudos to Dr. Todd Wood for that reminder). That could mean NASA is being overly cautious about this one, or that they are simply testing the waters. At any rate, such off-the-radar handling of this issue at least says that the interpretation of the data offered to the eager public is far from certain. I hope one item about the whole claim does not escape logic. These are *fossil* bacteria, not living bacteria. If the science is valid, then what it proves is that at one time there was bacterial life elsewhere. It does not prove that (a) it exists now, though that would seem reasonable; or (b) that it ever evolved into anything intelligent (for you evolution devotees, evolution is not self directing (!) — it must factor in environment, and no two environments or set of such conditions (like earth’s) is identical. But, it’s sad to say, the people who’d want this to be true for religious reasons (the ancient astronaut religion) will likely throw logic (and the need for actual data) to the wind. Another case of “this idea is in my head so that must mean it’s real” thinking, for which the UFO community is famous.
It’s hard to disagree with P. Z. Meyers’ assessment of the journal’s site (I have been on it and through it). But we shouldn’t judge a book by its cover. I don’t expect scientists to know much about web design or aesthetics. The people whose work populates the site are credentialed, And they are doing the right thing by soliciting the review of other experts and scientists. That’s how it’s supposed to work. But the editorial standards are apparently not very good. As one scientist from the University of British Columbia notes:
The journal proudly announces that it is obtaining and will publish 100 post-publication reviews. But did it bother getting any pre-publication reviews? It will be shutting down in a few months, after only two years of on-line publication (the 13 ‘volumes’ are really just 13 issues). Its presentation standards are pretty bad – there doesn’t seem to have been any effort at copy-editing or formatting the text for publication (not even any page numbers).
Chandra Wickramasinghe is the journal’s Executive Editor for Astrobiology, and presumably is the Editor responsible for this article. I heard him give a talk pushing panspermia about 10 years ago (the audience was an undergraduate science society at Oxford). The talk was very slick but dreadfully bad as science. The evidence he cited to support his arguments wasn’t actually untrue, but he twisted everything to make his arguments seem stronger than they were. He argued like a lawyer – his only goal seemed to be convincing the audience that his conclusion was correct, regardless of the contrary evidence that an unbiased consideration of the evidence would provide. Thus I wouldn’t trust his scientific judgment about anything concerning astrobiology.
Ouch. Take note of that, panspermia enthusiasts. (Wickramasinghe is basically the patron saint of panspermia theory).
Scientists have already weighed in (and of course to much less fanfare). Aside from the comments above about the journal, the same UBC scientist has this as her bottom line (click here for her analysis and reasons):
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.
Ouch again; that one might leave a mark.
Phil Plait of Bad Astronomy has a balanced piece over at Discover Magazine online on the article. Here is a notable section:
Hoover makes several claims to show that a non-biotic origin for these structures is very unlikely. I am not an expert and wont cast my vote either way here. This is not the first time Hoover has made such claims; he gave a similar presentation in 2007. There have also been many similar claims in the past. In fact, in the second episode of “Bad Universe” I interviewed NASA astrobiologist Dave McKay, who has also found very interesting features in a Mars meteorite that look a lot like bacteria. However, definitive proof is another matter. McKays opinion is that what he found was once alive, but he also was clear that scientifically he could not be sure (I found his skepticism to be well-grounded and at the right level, to be honest).
Probably the biggest bump in the road for showing these things are life-forms is to show they are not the result of Earthly bacteria getting inside the meteorite after it hit. This is very tough to do, though Hoover says this in his paper:
Many of the filaments shown in the figures are clearly embedded in the meteorite rock matrix. Consequently, it is concluded that the Orgueil filaments cannot logically be interpreted as representing filamentous cyanobacteria that invaded the meteorite after its arrival. They are therefore interpreted as the indigenous remains of microfossils that were present in the meteorite rock matrix when the meteorite entered the Earths atmosphere.
Clearly, Hoover thinks terrestrial contamination is unlikely. However, contamination, no matter how unlikely, is a more mundane explanation than extraterrestrial life, and Occams 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 for one appreciate the comment about the *need* to prove that such bacteria are not actually earthly bacteria. I noted that among some other problems for panspermia in my own essay on the subject (it dealt with defining various views of panspermia and the implications for Judeo-Christian theology).
So let’s wait and see, but to this point, we don’t have any real reason to think this will pass muster. Time will tell.