Tardigrades

A tardigrade is a cute little creature that’s about the size of a period at the end of a sentence. It looks like a stubby, eight-legged bear, and it’s found in wet environments all across the planet, so it’s also known as a “water bear.”

But a water bear doesn’t need water to survive. In fact, it can go into a bear-like hibernation whenever conditions get too extreme. That allows it to survive extreme hot and cold, crushing pressure — and even the radiation and vacuum of space.

Tardigrades have faced such conditions twice — in a Russian science capsule in 2007, and aboard a space shuttle in 2011. Both times the little critters were directly exposed to space, and in both cases many of them survived. They reanimated when they returned to the more comfortable environs of Earth.

Tardigrades were even launched toward one of the moons of Mars aboard a Russian mission a couple of years ago. But the craft never left Earth orbit, so the tardigrades lost out on the chance to be the first Eart