The tardigrade may be one of the smallest creatures on Earth (0.3 to 0.5 mm), but it also happens to be one of the most durable and can live in both boiling and freezing conditions, as well as being able to survive without food or water for more than 10 years, simply by allowing itself to dehydrate to less than 3% water, only to rehydrate itself when conditions permit.
The water bear, as it is also known, can even withstand 1,000 times more radiation than other creatures and survive in the vacuum of space, itself. In 2007, for instance, tardigrades were taken into low Earth orbit and after 10 days most of the tiny creatures were able to survive exposure to the vacuum of space and cosmic rays, with some tardigrades even withstanding lethal levels of UV radiation.
Scientists at the time then concluded that microgravity and cosmic radiation “did not significantly affect survival of tardigrades in flight, confirming that tardigrades represent a useful animal for space research.”
Recently, however, it seems tardigrade have now made their own way into space and according to Russian scientists have been discovered on the hull of the International Space Station 205 miles above the Earth’s surface. After discarding the possibility of the microorganisms clinging to rockets which were originally launched from Baikanour, Kazakhstan, scientist now believe they hitched a ride on atmospheric currents which subsequently carryied them all the way to the ISS.
Needless to say, their appearance has shocked scientists and lends further credence to the theory that “organic life may have spread across space traveling on comets and asteroids.”