Tardigrades Survive in Space

The ability of a microscopic animal to withstand the vacuum of open space sounds like science fiction, but it was confirmed by a 2007 European Space Agency mission. Researchers sent dehydrated tardigrades, also known as "moss piglets," into low Earth orbit for ten days. They were exposed directly to the void and lethal levels of solar radiation. Astonishingly, upon their return to Earth and subsequent rehydration, many of the tardigrades were revived, and some even went on to lay healthy eggs, proving they had survived the ordeal completely unprotected.

This remarkable feat is possible through a state of suspended animation called cryptobiosis. When faced with an extreme environment, whether it's a lack of water, freezing temperatures, or the vacuum of space, the tardigrade can shed over 95% of its body's water. It retracts its legs and curls into a tiny, desiccated ball called a "tun." In this form, its metabolism slows to less than 0.01% of its normal rate, essentially pausing all biological processes. Unique sugars and proteins within its cells form a protective, glass-like substance that prevents cellular structures and DNA from being destroyed, allowing the creature to reanimate, sometimes decades later, once conditions become hospitable again.