Tardigrades, affectionately nicknamed "water bears," are some of the toughest organisms on Earth. These tiny, eight-legged creatures are only about 0.5 millimeters long, but they can survive extreme environments that would obliterate almost any other life form.
Water bears have been found thriving in the deepest parts of the ocean, the highest mountain peaks, and even in outer space! In 2007, scientists sent tardigrades into space, exposing them to the vacuum and radiation of low Earth orbit. Incredibly, when they returned to Earth, many of them were still alive.
Their secret? Cryptobiosis—a state where they dry out, curl up into a tiny ball called a "tun," and nearly shut down all biological processes. In this state, tardigrades can survive freezing, boiling, radiation, dehydration, and crushing pressure.
It’s amazing to think that one of the mightiest survivors on Earth is something you could barely spot under a microscope!