More than 3 miles down in the Caribbean Sea, a remote-controlled vehicle has filmed the world's deepest "black smoker" vent: a gusher of iron sulfide so hot it could melt lead. "It was like wandering across the surface of another world," the geologist who piloted the vehicle tells LIveScience. "The rainbow hues of the mineral spires and the fluorescent blues of the microbial mats covering them were like nothing I had ever seen before."
Despite the scorching heat, alien-like creatures thrive near these vents, including tubeworms, giant clams, and eyeless shrimp, says LiveScience. Until now the deepest known vent was 2.6 miles down. (Read more black smoker stories.)