Recently, I stumbled upon the Wikipedia page for panspermia—a concept I was already familiar with, relating to the theory that life on Earth might have originated from an external source. Specifically, a primitive microorganism might have landed here on a meteorite (or, in some versions of the theory, on an alien probe).
While reading about panspermia—a theory that has gained a lot of scientific traction in recent years—I encountered a term I hadn’t seen before: extremophile. It refers to “a microorganism, especially an archaean, that lives in conditions of extreme temperature, acidity, alkalinity, or chemical concentration.” In other words, a really tough bug. Tough to live in the deepest of the ocean, or even in the earth’s mantle.
Recently, I stumbled upon the Wikipedia page for panspermia—a concept I was already familiar with, relating to the theory that life on Earth might have originated from an external source. Specifically, a primitive microorganism might have landed here on a meteorite (or, in some versions of the theory, on an alien probe).
While reading about panspermia—a theory that has gained a lot of scientific traction in recent years—I encountered a term I hadn’t seen before: extremophile. It refers to any microorganism that has evolved to exist in an environment so extreme that most other life would be prohibited. Examples of such environments are hydrothermal vents, salt-ridden lakes, and frozen ice sheets.
Or, perhaps, outer space.
Apparently, the concept of extremophiles—and of panspermia, in general—has taken on new relevancy in the past ten years. Even as we find more and more exoplanets (the most recent count is around 2,000), we have yet to find a single sign of life, intelligent or otherwise. This has led some cosmologists to adopt the so-called Rare Earth Hypothesis, which stipulates that while earth-like planets are a dime-a-dozen, actual Earths—that is, planets with life—might be fabulously uncommon. In fact, there might have only been a few in the early universe, from which all the other life-bearing planets were seeded. This could happen either accidentally (from asteroids; hence the extremophiles) or intentionally (from aliens deliberating spreading life across the galaxies).
All this speculation struck a chord with me. For one thing, it took me back to my youth, to all the sci-fi books and films I consumed. The idea of alien invaders taking the form of germs or seeds goes all the way back, I think, to Jack Finney’s classic The Invasion of the Body Snatchers, in which the evil “seed pods” are actually alien weeds that travel from planet to planet on the solar wind.
Continue reading “Today I Learned a Word: Extremophile”
Ash Clifton, Writer 