Tardigrades, also known as "water bears," are hardy little creatures ranging from under below 0.1 mm to 1.5 mm. Seemingly against all logic, they can survive temperatures as cold as near absolute zero to over a scorching 300 °F, go for a decade without water and withstand almost 1,000 times more radiation than the rest of the puny creatures on the earth.
So what do scientists do with these invincible little marvels? Toss them into space. They already look like aliens, after all.
Two species of tardigrades ventured into the great beyond on an ESA satellite a year ago. After 10 days in space, the little guys were brought back for study. It was found that the Sun's UV rays, 1,000 times stronger in space than here on Earth, would oddly act as tardigrade Kryptonite. Of those shielded from the rays, nearly 70% went on to reproduce successfully. Of those exposed to the Sun, almost all of them died. Still, the intrepid buggers are now the first creature ever known to be able to survive in open space.
Via Book of Joe