Science fiction meets fact at this surrealistic outpost. From 1991 to 1993, eight researchers lived within a three-acre glass-enclosed terrarium, a self-sustaining laboratory sealed off from the outside world. Visitors now may tour "the whole world" in a single afternoon: There's a million-gallon ocean, a tropical rain forest, a savanna, a desert and other environments and life forms of Biosphere 1, also known as Planet Earth.