Down to a Sunless Sea

Deep under the ocean’s surface, there is another land, where air is replaced by water, the pressure is crushing, and animals depend on cloud of boiling-hot chemicals to survive. These clouds, which would poison most animals, come from hydrothermal vents, one of the most important scientific discoveries of the twentieth century. Follow the scientists who first saw the strange creatures that live at the vents, and find out how oceanographers today are working to understand these puzzling deep-ocean environments.