Biosphere 2

Biosphere 2 Review

In the town of Oracle, about 30 minutes northwest of Tucson, this self-contained, closed ecosystem opened in 1991 as a facility to test nature technology and human interaction with it. The miniature world within Biosphere, now managed by the University of Arizona, includes tropical rain forest, savanna, desert, thorn scrub, marsh, ocean, and agricultural areas, including almost 3,000 plant and animal species.

A film and a large, rotating cutaway model in the visitor center explain the project, which included two "human missions" wherein scientists entered the ecosystem for extended periods of time—once for six months, once for two years.

Guided walking tours, which last about two hours, take you inside some of the biomes, and observation areas let you peer in at the rest. A snack bar overlooks the Santa Catalina Mountains.