Flickr The deepest-ever sample of rock was taken from the Earth’s mantle. The warmer, softer layer makes up 80% of the Earth’s bulk, and is usually hidden below miles of hard crust. In one region of the Atlantic Ocean, though, it has pushed up. A drill ship took a 1,268-meter (0.8 mile) core sample of greenish marble-like rock. “We… only planned to drill for 200 meters,” one scientist told Nature, but the drilling was surprisingly easy, “so we just decided to keep going.” Life may have started near deep-ocean vents, so the rock’s mineral content could help explain our origins. It’s not the deepest hole ever drilled: That is a 7.6-mile hole in the Kola Peninsula, Russia. |