57K views · 1.2K reactions | They've endured the vacuum of space and all five of Earth's mass extinction events, but did you know that tardigrades could be incredibly useful for medical research? Here are five facts about these microscopic extremophiles. | National Geographic Science | Facebook

For centuries, healers had no notion of what caused disease. Then came the microscope, and the discovery of a hidden realm we never knew existed. #Origins New Tonight 9 | National Geographic TV