Every so often, a news story comes along that puts our concerns about American politics – heck, terrestrial politics -- in different context altogether. Here's one:
NASA scientist says some comets may hold critters. Well, not cat-plays-piano critters. More like what Antony van Leeuwenhoek called "animalcules
" -- a kind of bacteria.
Richard B. Hoover is an expert on "extremophiles," life that thrives on earth in conditions too hot, cold, high or deep for most things. But he's also been interested for a while in the possibility that life on this planet may have been seeded billions of years ago by stuff that landed from Elsewhere. He is president of SPIE -- the international society for optical engineering
-- and is astrobiology group leader in the Space Science Department of the NASA Marshall Space Flight Center.
Hoover's new paper is titled "Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites: Implications to Life on Comets, Europa, and Enceladus."
It's published in the Journal of Cosmology, a quirky online publication with an, ahem, stellar cast of editors and reviewers.
Here's his punchline: "The detection of microfossils of cyanobacteria and other filamentous trichomic prokaryotes in the CI1 carbonaceous meteorites (which are likely cometary crustal remnants) may be interpreted as direct observational data in support of the Hoyle/Wickramasinghe Hypothesis (Wickramasinghe 2011) of the role of comets in the exogenous origin of terrestrial life."
Translation: Life on earth may be descended from critters from comets.
What's his proof? I'll summarize:
He looked at examples of an extremely rare form of meteorite, the "CI1 Carbonaceous." Only nine have ever been recovered. Unlike most meteorites, which are some variant of solid rock, the CI1 are more like soft clay, and they contained water when they landed. Because comets are basically dirty snowballs in space, some scientists think that these particular meteorites split off from comets that strayed close enough to the earth.
Basically, Hoover and his associates took three of the meteorites, very carefully cut them open, and looked at the insides using a powerful electron microscope. And he found stuff that looks remarkably like some modern bacteria. So much so, in fact, that Hoover says it's likely that they are fossils of bacteria from Someplace Else.
A growing number of other scientists say it's likely that much of the material needed to support life on Earth -- ammonia, amino acids and even water -- originally landed in the form of meteorites. But this is a much more audacious idea: That living things themselves fell from the sky.
This isn't the first time Hoover has advanced his particular claim. He's been talking and writing about findings from some of these meteorites at least since 1998.
And he's hardly the first person to get headlines with a claim to have found fossils in a meteorite. The most famous prior example is probably David McKay, also of NASA. A few years ago, he advanced the theory that he'd identified microfossils in a meteorite
that most scientists agree is of Martian origin. The claim remains extremely controversial, partly because McKay's possible fossils are much, much smaller than earthly bacteria.
Hoover's possible fossils, on the other hand, are about the same size as terrestrial microbes and even appear to share some structural features.
Is Hoover right? "Extraordinary claims require extraordinary proof." If I'm betting, I'm betting he's wrong because the smart money always goes against the unlikely. But once in a while the unlikely proves to be true. That's how science advances, after all.
Scientific critiques of Hoover's paper will surely be coming hard and fast. The Journal of Cosmology has taken an extremely unusual step to solicit and publish these critiques. As editor-in-chief (and Harvard professor) Rudy Schild put it
"Given the controversial nature of his discovery, we have invited 100 experts and have issued a general invitation to over 5,000 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."
Among the issues sure to be raised: The possibility of contamination by earthly bacteria (Hoover addresses that in some detail in the paper) and the possibility that what looks like bacteria may be an illusion – the way a constellation may look like a scorpion without actually being a scorpion.
To which you may well ask: So what? None of this will affect the price of oil or the fate of Libya or the possibility that [insert GOP-er here] will decide to run against Obama.
Well, maybe this story will get us all thinking about our common origins and our common problems – whether or not our great-to-the-billionth-grandpa actually did
hitch a ride here on a comet. I'm not going to be able to improve on Joni Mitchell's lyric:
We are stardust, we are golden,
We are billion-year-old carbon,
And we got to get ourselves back to the garden.