This is Part 5 of a 6-part series telling the story of humankind’s efforts to understand the origins of life, by looking for it in extreme environments where life thrives without relying on the Sun as an energy source. In this installment, scientists use high-tech submersibles to explore the seafloor and bring intriguing samples up to the surface.

Chris German of the Woods Hole Oceanographic Institution led an expedition to the Mid-Cayman Rise. As the shop Atlantis, was bearing down on potentially the most significant sampling of hydrothermal vent sites on the planet, German hoped real discoveries would be waiting for the team somewhere about 400 miles south of Havana. Using the Jason submersible and its partner vehicle Medea, German and his team collected grabbed temperature readings, biological samples and close-up shots of the vents.