“Jules Verne would have dug this plan: drill into the sea floor, through kilometres of the planet’s rocky crust to penetrate the denser underlying mantle. It is one of geology’s classic quests, conceived almost 60 years ago, at the peak of the plate-tectonics revolution. Since then, many have attempted it and failed. But an expedition starting this month is taking up the challenge once again. In early December, the drill ship JOIDES Resolution will depart Colombo, Sri Lanka, and head for a spot in the southwestern Indian Ocean known as Atlantis Bank. There, it will lower a drill bit and try to screw it through 1.5 kilometres of rock, collecting a core sample as it goes. If all goes well, future expeditions — not yet scheduled or funded — will return and finalize the push into the mantle (see ‘Deep understanding’).”