No room for error

Casey Machado, Daniel Gomez-Ibanez, Andy Bowen, and James Kinsey carefully lower the new hybrid underwater robotic vehicle Nereus into place in its cradle on the deck of the R/V Cape Hattaras during an October 2009 expedition to search for deep-sea hydrothermal vents along the Mid-Cayman Rise — maximum depth is just over 6,800 meters (4.2 miles) deep. The expedition turned up three distinct types of hydrothermal venting. The work was conducted as part of a NASA-funded effort to search extreme environments for geologic, biologic, and chemical clues to the origins and evolution of life.

(Photo by Chris German, Woods Hole Oceanographic Institution)