Tardigrades, or water bears, are microscopic organisms that have been studied for years for their extreme resilience to potentially harmful conditions. They require a thin layer of water to do anything- eating, moving, reproducing, etc. They are found all over the Earth, however, including in some of the driest environments on the planet. They are able to survive conditions like this because of their ability to enter a state in which they retain only 3% of the water in their body, and slow their metabolism down to under one one-hundredth of its normal rate. They are able to stay in this state for a decade, possibly longer. This gives them the unique ability of being able to survive in the vacuum of space.
In 2007, a team of European researchers sent a craft into orbit that contained several tardigrades, and the craft remained in orbit in the vacuum of space for 10 days. Upon returning to Earth, the researchers found that nearly 70% of the tardigrades on-board had survived the journey. This is remarkable, considering that a human in space would last about 15 seconds before losing consciousness, and would die shortly thereafter. The lack of oxygen and extreme temperature aren’t the only problem the tardigrades overcome, either. There is a large amount of radiation in space that we are protected from by our atmosphere, and the tardigrade has somehow evolved to survive this as well. This sturdy creature shows that there is a possibility for life in the harshest environments, and not only on Earth.