Tardigrades Survived Exposure to the Vacuum of Space and Cosmic Radiation

Meet the tardigrade, also known as the water bear or moss piglet. At less than a millimeter long, these eight-legged microscopic animals look almost cartoonish — but they are arguably the most indestructible animal on Earth.

In 2007, the European Space Agency's TARDIS mission attached dehydrated tardigrades to the outside of the FOTON-M3 satellite and exposed them to the open vacuum of space for 10 days. When they returned, scientists added water to rehydrate them. Most woke up. Many laid viable eggs.

What Tardigrades Can Survive

• Temperatures from -272°C (near absolute zero) to +150°C
• Pressures from the vacuum of space to 6,000 atmospheres (deeper than the deepest ocean)
• Radiation levels 1,000 times the lethal dose for humans
• Dehydration for over 30 years — they reduce their water content to less than 3% and enter a "tun" state
• The vacuum of space with full UV exposure

How They Do It

Tardigrades produce specialized "TDPs" — tardigrade-specific intrinsically disordered proteins — which form a glass-like matrix inside cells when dried, protecting their DNA and proteins from damage. Researchers are now studying these proteins for applications including vaccine preservation without refrigeration.