Could an animal survive in outer space? Meet tardigrades, tiny animals also called water bears! They are less than 1 millimeter long, so you need a microscope to see them clearly. They can survive in extreme cold, heat, and long periods without water. When conditions become harsh, tardigrades lose most of their body water and enter a resting state called cryptobiosis. Their bodily processes slow dramatically until conditions improve. Some tardigrades have even survived exposure to the vacuum of space for a limited time. These tiny animals are amazing survivors!