Tardigrades - A glimpse into the future
Tardigrades are some of nature’s most unique creatures. They are immune to almost any disease, can survive without water for multiple days, and even can withstand the cold vacuum of space. These tiny creatures are so indestructible that some scientists have jokingly called them immortal. But, according to recent studies, these tiny animals might be the key to life on new planets.
Before going into how these tiny creatures can help us discover if life is suitable for animals on extraterrestrial land, first we need to talk about how these creatures look. Discovered in the 1700s by German scientist Johann August Ephraim Goeze, he originally called them kleiner Wasserbaer, meaning small water bear. Tardigrades are small creatures, usually around 0.5 millimeters or 0.2 inches in size. Additionally, they look like a hybrid of a small bear and a manatee, hence the name small water bear. Their diet primarily consists of sucking the juices of various algae and lichen, but some tardigrade species are known to be carnivores and even cannibals. Some species of tardigrade eat other tardigrades just to survive.
So, what are their characteristics? Tardigrades are practically indestructible, being able to survive in almost any climate. But how? When in an extreme climate, Tardigrades enter an extreme state known as Cryptobiosis. In this stage, their metabolism drops down to a level 0.01% of what it usually is, along with their organs being protected by a gel called Trehalose. Additionally, to help further protect their bodily functions, they also produce antioxidants and produce a protein that helps protect their DNA. In colder temperatures, their bodies create a special feature, called a tun, that prevents the growth of ice crystals. Furthermore, they have another defense while in water. In water with low amounts of oxygen, they will stretch out and reduce their metabolic rate. This way, their muscles can absorb oxygen, allowing them to survive. As stated earlier, Tardigrades can survive in any climate. They can go up to 30 years without food or water, they can live in climates near absolute 0, and they can withstand pressure 6 times the pressure of the ocean’s deepest trenches! However, how can these highly indestructible species help advance our quest to other planets?
Scientists have recently been working on a theory called Panspermia, which means animals, like Tardigrades, hitchhiking between planets. In 2019, an Israeli lunar lander crashed on the moon carrying Tardigrades, and now, due to their unique characteristics, they may be the first organisms to land on the moon. Additionally, scientists have been testing the theory of Panspermia with Tardigrades. Most recently, scientists have been working on shooting them out of a high powered cannon, simulating an impact on another planet. Unfortunately, not all the Tardigrades survived the high powered blast, but hope isn’t lost for the Panspermia community. Most Tardigrades survived, and even if they aren’t the best suited for this activity, there are species of Tardigrade that are much stronger than the ones tested.
These microbial animals may look small, but they are some of the most indestructible organisms on the planet and they may hold the key to interplanetary travel in the near future. All in all, these organisms are some of nature's most unique creatures, and we may learn a lot more from these small water bears.
