Don’t know what a tardigrade is? Well, going by the word, what would you expect? Something scholastic, perhaps? After all, tardy is a word for ‘late’ used only by teachers, and usually just the ones you don’t like much, and grade is a school word par excellence. Or maybe it’s an Eastern Europe city, like Belgrade? Or perhaps it’s something science-fictiony… there is that echo of TARDIS, after all.
Well, imagine a creature that can survive in outer space. Imagine one that already has. On a space shuttle. Outside a space shuttle. This is a beastie that can withstand pressures several times as strong as those at the bottom of the ocean. It can withstand temperatures well above boiling, and close to absolute zero. It can withstand radiation in doses hundreds of times what would kill you or me. It can go without food and water for years. It can survive indefinite dehydration to 3% of its usual body water or less and then, when rehydrated, go on as if nothing had happened.
I mean, holy cow. And it’s got claws like bears. Eight of them: four pairs of legs. And it has a hard shell, and lays eggs. And it looks like a bear with no eyes and a mouth like an auger or something: apod.nasa.gov/apod/ap130306.html. And it’s everywhere. Go for a stroll in a forest and they’re probably all around you. Dude, I’m not making this up.
Naturally, the only sort of critter that could possibly do and be all this is a very small one. And thank your lucky stars for this. (Some people think tardigrades actually came from nearby stars. It’s not entirely implausible.) Tardigrades are generally less than a millimetre long. (For my American readers, a millimetre is about 1/24 of an inch. Oh, and by the way, only three countries in the world don’t use metric: the US, Liberia, and Myanmar. Just going to leave that with you.)
A couple more things: it’s also called a water bear, and it lumbers kind of like a bear too. It’s not an especially fast-moving thing. In fact, that’s where its name comes from: Latin tardus ‘slow’ and gradus ‘walking’, by way of French. This indestructible intergalactic juggernaut is at least not a fast-moving one.
And, just to complete the picture, I must tell you it’s a stripper too. You may know that the fancy term for a stripper (peeler, exotic dancer) is ecdysiast. Well, tardigrades belong to the superphylum ecdysozoa – stripper life-forms. They shed their outer layers every so often – moulting, or, as biologists call it, ecdysis.
Isn’t that just incredibly charming and pleasant? Click-drag this beastie to about ten thousand times its current dimensions and you have something pretty near perfect for a sci-fi horror flick. But maybe give it a different name, something with a little less tard and grade.