This is a story about meteorites. Well, meteorites, and life. WELL, meteorites, life, and totally misleading headlines.
I know what you’re thinking. No, this isn’t about the Orgueil meteorite, which in the 19th century caused a ruckus when a conman embedded some grass seeds in it and claimed it proved exobiology. Nor is it about Richard Hoover’s claims, referencing the exact same meteorite, for the third time in his career (first in 2004 then in 2007!). This time around, he’s gaining news traction despite not actually having a discovery. I have precious little to say about it that isn’t already said elsewhere. The Orgueil meteorite is not news, nor is it alien life, no matter how desperately I wish it was.
No, this is, instead, about this science-ish pablum written by the good folks over at The Independent, a UK-based newsish organization. I use the “ish” to denote my skepticism that either adjective fits the subject. In putting together what I can only assume was intended to be a thought-provoking science piece, they’ve succeeded not only in making a mockery of the hunt for life elsewhere in the universe, but also for the hunt for the reasons life exists back at home base. They’ve succeeded also at one more thing, incidentally — in provoking my ire for the unthinking hyperbole that passes for science media these days.
The piece in question begins with the blaring headline: “We’re all aliens… how humans began life in outer space”. Sound like we’re setting up an argument for panspermia, where life itself began elsewhere in the universe and was carried via meteor to Earth by some cosmic happenstance in the projectile ballet we call our cosmos’ set of physics? That’s because other hypotheses have argued for exactly what I’ve described, though they multiply entities unnecessarily and thus Occam’s Razor slices them neatly down to the low probabilities they enjoy presently. And as the rest of the article will soon make clear, they’re not talking about us being aliens at all — only that our constituent components may have extraterrestrial origins. Knowing what we already know about this universe, I have to rebut with: “DUH.” And also: “You’re not an extraterrestrial if you’re born on this planet, asshole.”
The article proceeds from its already rocky start, to making a number of claims that are hardly news and that put the lie to the assertion in the title: the chemicals that make up our planet’s biosphere probably come from outer space.
In fact, a growing body of evidence is now pointing to deep space as the possible source of the raw materials that formed the building blocks of life. The latest study, which focused on a class of meteorites that fell on to the Antarctic ice sheet, also suggests that life’s origins may have been extraterrestrial.
An analysis of the meteorites has revealed that these rocks can be induced, under high pressures and temperatures, to emit nitrogen-containing ammonia, a vital ingredient for the first self-replicating molecules that eventually led to DNA, the molecule at the heart of all life.
Know what else is needed for life? Carbon. Since the only atoms created during the Big Bang were hydrogen and helium, every carbon atom on the planet was built in a star’s supernova billions of years ago. So does that make us “aliens”? Like hell it does. Water probably came from orbital bombardment too — at least, that’s the frontrunner for hypotheses about its origin, but it’d be farly difficult to find the remains of an ice comet billions of years after the fact. The origin of nitrogen, or any other constituent element of the amino acids that are capable of self-arranging and eventually evolving into life as we know it, is certainly an important factor in determining with any level of confidence Earth’s early history.
I will give the scientists a pass. They’re working some pretty detailed experiments that border on the very furthest edge of what we can hope to ascertain about Earth’s early history. They’re not the ones making the odious claims I dislike about the science “reporting” in the Independent. They claimed this:
“What is important is the finding of abundant ammonia. Nitrogen is an indispensable ingredient for the formation of the biopolymers, such as DNA, RNA and proteins, on which life depends, and any theory that tries to explain life’s origin has to account for a supply of ‘usable’ nitrogen,” Professor Pizzarello said. “Therefore, its direct delivery as ammonia and in relatively large amounts from the nearby asteroids could have found a ‘prebiotic venue’ on the early Earth.”
It’s this pullquote that was so obviously mangled not only by the paper’s editor in the ridiculously overinflated headline to pull views, but also by the author of the piece, Steve Connor, in his initial paragraph: “As scientific mysteries go, this is the big one. How did life on Earth begin? Not how did life evolve, but how did it start in the first place? What was the initial spark that lit the fire of evolution?”
He’s describing abiogenesis. While that’s certainly the best theory we have right now, the one that fits all available evidence with the least amount of shoehorning or multiplying entities unnecessarily, that doesn’t mean the people investigating how all this nitrogen got here are even looking sidelong at that aspect of the planet’s history outside the pullquote. Even if abiogenesis wasn’t the accepted theory, there’s every reason to ask “why’s all this nitrogen here to begin with?” It doesn’t have nearly the implications that Connor feels it does, nor that Prof. Pizzarello is quoted as explaining. The galling part about this is, I realize that Pizzarello very likely intended to play science populist in explaining things as he did to Connor. Not every scientist can be their own publicist. Media types evidently have this uncanny knack for pulling the most interesting soundbite from any sentence and blowing the whole story out of all manner of proportion, and I strongly feel the professor was wronged here. I sympathize completely with his excitement, and with his explanation of the implications of his research and why it should continue.
Understanding the nitrogen’s origin, or the origin of any other constituent atom in our biosphere, is a necessary component of any fully formed theory of life’s origins, whether abiogenesis or some other better explanation should one ever come along. It is not, however, a sufficient condition, by any stretch of the imagination. This constant stretching of the truth in science reporting is deplorable in its lack of nuance, and directly leads to much of the mistrust and ill will toward science in general harbored by those people that are burned time and again by the “maybe it’ll cure cancer!” headlines they’re bombarded with daily.
Not every investigation of every phenomenon or historical event is going to unearth the deepest mysteries known to mankind. Sometimes an ammonia-filled meteorite is just an ammonia-filled meteorite.