But they proved to be radically different. They relied for energy not on sunlight, as all other life does, but on chemicals bursting forth from the Earth's interior. Not long after that historic dive, other scientists came upon their first black smoker chimneys. They are called black smokers because they belch particle-laden, superheated water that looks like black smoke. The particles, composed primarily of sulfides, precipitate in a constant rain to form, directly below the belching smoke, an ever-growing chimney of stone.
Black smokers look like miniature volcanoes in a constant state of eruption.
Besides the particles, the eruptive material includes hydrogen sulfide, a chemical that heat-loving bacteria help convert into food for creatures higher up the food chain. Black smokers, which are a form of hydrothermal vent, make ideal homes for that strange community of life first seen in 1977. Black smoker erupting on the Juan de Fuca Ridge. They were getting into big questions, questions whose answers could only be approached through intense study of the geology and biology of black smokers. But studying black smokers in their natural habitat is as daunting a task as studying rocks on Mars.