Tardigrades Survive Outer Space

Often called water bears or moss piglets, these microscopic invertebrates are arguably Earth's toughest animals. Their pudgy, eight-legged appearance belies an ability to survive conditions that would be instantly fatal to nearly any other life form. This incredible resilience stems from a state of suspended animation known as cryptobiosis. When faced with a life-threatening environment, a tardigrade can enter this state by curling into a desiccated ball called a tun, retracting its legs, and expelling up to 97% of its body's water.

In this tun state, a tardigrade's metabolism slows to less than 0.01% of its normal rate, making it virtually undetectable. Special sugars and proteins unique to the tardigrade fill its cells, forming a glass-like matrix that protects vital structures from damage caused by dehydration or freezing. This isn't just a laboratory finding; it was proven in 2007 when scientists sent tardigrades into low Earth orbit aboard the FOTON-M3 mission. Exposed directly to the harsh vacuum and intense solar radiation of space for ten days, many not only survived the journey but were successfully rehydrated and went on to reproduce back on Earth.