Close to midnight on February 15, 1977, a remotely operated still-camera sled that was photographing the floor of a mid-ocean ridge northeast of the Galápagos Islands recorded an unusual spike in the temperature of the otherwise freezing waters. The team of scientists controlling the camera sled from a nearby research vessel initially wrote off the reading as an anomaly. But hours later, when they reviewed the hundreds of photos snapped by the camera, they saw that in the few seconds corresponding to the temperature spike, the sea floor had morphed from a barren volcanic landscape into a dense and thriving agglomeration of clams and mussels. On February 17, a three-person team plunged 8,000 feet below the ocean’s surface in a research submersible to investigate that very spot. They found an oasis of misty-blue, 46°F waters, shimmering with manganese and other mineral precipitates. But that wasn’t all they saw.
“Isn’t the ...
