These animals can survive until the end of the Earth, astrophysicists say

Tardigrades have a reputation as the toughest animals on the planet. Some of these microscopic invertebrates shrug off temperatures of minus 272 Celsius, one degree warmer than absolute zero. Other species can endure powerful radiation and the vacuum of space. In 2007, the European Space Agency sent 3,000 animals into low Earth orbit, where the tardigrades survived for 12 days on the outside of the capsule.

To a group of theoretical physicists, tardigrades were the perfect specimens to test life’s tenacity. “Life is pretty fragile if all your estimates are based on humans or dinosaurs,” said David Sloan, a theoretical cosmologist at Oxford University in Britain.