Turkey’s Mount Chimaera is on fire, and has been for millennia. Dozens of campfire-sized flames burst straight of the mountain’s rocky, sea-facing slope. These eternal flames are fueled by methane, the odorless, colorless substance that provides much of our natural gas for fuel, as well as a potent greenhouse gas.

Most methane (a single carbon atom surrounded by four hydrogens) forms from the decay of ancient plants, animals and other life. But the Earth itself can create methane, too. Wh