What do you think of this fact?
No air, brutal cold, relentless radiation: space is about as hostile to life as it gets. A human without a spacesuit wouldn’t last long out there. Tardigrades, on the other hand, made it.
A ride on Foton-M3
In September 2007, the European Space Agency launched its Foton-M3 mission. On board: about 3,000 tardigrades, also known as water bears. The tiny animals were dried out and then exposed to open space for 10 days, meaning vacuum and cosmic radiation.
The result surprised even the scientists. According to ESA, project leader Ingemar Jönsson said the space vacuum, with its extreme dehydration, and cosmic radiation “were not a problem for water bears.” Vacuum alone had no significant effect. ESA calls them the first animals to survive exposure to space.
The sun was the real problem
They’re not invincible, though. Things got dangerous when unfiltered UV light from the sun was added to the vacuum. Only 1 percent of the species Richtersius coronifer survived, while Milnesium tardigradum did much better: 68 percent of those exposed to a limited UV dose survived. Many still died in the days after.
Tiny animals, big tricks
Tardigrades are usually about 0.5 millimeters long, and the biggest species reach 1.3 millimeters. They got their nickname from Johann August Ephraim Goeze, who described them in 1773 as “little water bears.” Today about 1,500 species are known.
Their secret is called cryptobiosis. When things get too dry, they pull in their legs and head, dry out and shut their metabolism down almost completely. In this “tun” state, they can go years without food or water. Add water, and they come back to life.
At least briefly, tardigrades can survive temperatures from −272 °C to +149 °C.
They live in moss, in the ocean and probably somewhere near you right now. The toughest animals on the planet would fit on the head of a pin with room to spare.