In the dark ocean depths, kilometers beneath the waves, scalding water spews from hydrothermal vents as it has for billions of years. Bubbling up at the breaks between Earth's plates, that water is a searing brew of minerals dominated by black iron sulfide. As it billows upward in vast quantities, the minerals roil like smoke from a raging fire. It looks like a place that ought to be dead as stone. Yet on the ancient Earth, that abundant black mineral might have been the crucial ingredient that first sparked all life, some scientists say. As they see it, the simplest life forms got their start within tiny cell-like chambers in iron sulfide rqck that settled out from the hydrothermal vents' exhalations.
展开▼