HOT HOUSE?

Think your house is weird? Try living in chimneys of boiling water on the ocean floor. That's where some of Earth's most primitive forms of bacteria, or tiny organisms, reside--right inside chimneys or vents known as "black smokers."

To investigate how such microbes can exist in such extreme conditions, a University of Washington research team sailed to the Juan de Fuca Ridge, a deep-sea mountain chain 290 kilometers (180 miles) off the coast of British Columbia. There researchers hauled up four of the chimneys from the ocean floor in June 1998.

The vents are called black smokers because dark clouds of mineral-rich, super-heated (up to 300 [degrees] C) sea water spews out of the chimney's top from beneath Earth's crust. As the water collides with the freezing ocean, mineral grains settle, eventually piling up to create solid, hollow towers 14 stories tall that weigh several tons.

It turns out the minerals offer the key to survival for the bacteria. The very existence of such microbes has shaken scientists' long-held theories about the origins of life on Earth. "These bacteria are the bottom of the food chain, and they support tube worms, giant clams and strange crabs in the neighborhood who feed on them," says Edmond Mathez, a curator at New York's American Museum of Natural History.

Sunlight never penetrates the deep ocean, and the chimney bacteria are among few living organisms on Earth that don't rely on the sun for energy and nutrients--the essentials of life. Scientists have discovered the microbes use minerals as food through chemical reactions called chemo-synthesis, without help from the sun. Scientists now surmise that similar life forms may exist beneath the ice-packed surface of Jupiter's moon Europa, for example.

To haul up the black smokers from the ocean floor, researchers launched a remote-controlled machine fitted with a robotic arm and chainsaw to cut through each chimney. The robotic arm delicately placed cables, attached to the mother ship, around each towering vent, and slowly reeled in the smokers to the surface. Immediately biologists gleaned samples of still-live bacteria, and the scientists continue to study them for more top secrets to life's origins.