Beyond dryness, tardigrades can also tolerate other extreme stresses: being frozen, heated up past the boiling point of water, high levels of radiation, and even the vacuum of outer space. This has led to some erroneous speculation that tardigrades are extraterrestrial beings. While that's fun to think about, scientific evidence places their origin firmly on Earth where they've evolved over time. In fact, this earthly evolution has given rise to over 1100 known species of tardigrades and there are probably many others yet to be discovered. Because tardigrades are so hardy, they exist just about everywhere. They live on every continent, including Antarctica. And they're in diverse biomes including deserts, ice sheets, the sea, fresh water, rainforests, and the highest mountain peaks. But you can find tardigrades in the most ordinary places, too, like moss or lichen found in yards, parks, and forests. All you need to find them is a little patience and a microscope. Scientists are now trying to find out whether tardigrades use the tun state, their anti-drying technique, to survive other stresses. If we can understand how they, and other creatures, stabilize their sensitive biological molecules, perhaps we could apply this knowledge to help us stabilize vaccines, or to develop stress-tolerant crops that can cope with Earth's changing climate. And by studying how tardigrades survive prolonged exposure to the vacuum of outer space, scientists can generate clues about the environmental limits of life and how to safeguard astronauts. In the process, tardigrades could even help us answer a critical question: could life survive on planets much less hospitable than our own? University Wyoming biologist Thomas Boothby leads an experiment aimed at uncovering the survival mechanisms of tardigrades in space. He notes that these tiny organisms may produce more antioxidants to counteract the harmful effects of increased radiation exposure during space travel. By studying how tardigrades adapt and what specific genes activate or deactivate in response to both short-term and long-term spaceflight, researchers hope to understand their resilience better. NASA's research team will analyze which tardigrade genes are influenced by the stresses of spaceflight, potentially identifying unique gene responses to this environment. By determining which genes are essential for tardigrade survival under these conditions, the findings could inform strategies to protect biological materials like food and medicine from extreme conditions, contributing to the success of long-duration deep-space exploration missions.