Also known as the water bear, tardigrades are minuscule, eight-legged invertebrates that are usually found on lichens and mosses. They are called water bears because their stance is reminiscent of bears.
They are also found on beaches, sand dunes, and freshwater. Most tardigrades average at just over a millimetre in size, making them visible with the help of a low powered microscope. So what makes these humble tardigrades different from other organisms on the earth?
These animals are capable of surviving extreme environmental conditions that will immediately turn fatal for every other life form. For instance, water boils at 100°C, these organisms are able to withstand temperatures of over 150°C. Apart from extreme heat, these creatures are able to survive at – 272 °C, which is just a degree warmer than absolute zero!
Water to Glass
When the environment that the tardigrades live in become unfavourable, they can almost stop their metabolism and the water content in their body drops to 1% of the original. In this state, their cell structure changes, where the cells take on a glassy appearance, protecting all their organelles. Moreover, their DNA is protected by special proteins that protect it from radiation.
Space is a vacuum, where the pressure is almost non-existent. Tardigrades are able to thrive in the near-vacuum conditions for at least 10 days. Furthermore, space is a harsh environment where radiation levels are very high. Gamma radiation, the most potent form of radiation can damage DNA and cause radiation poisoning. But the tardigrades can survive even this radiation as they can effectively repair their DNA structure after exposure. What this means is, tardigrades can survive almost 1,000 times more radiation than any other animal!