Biosphere 2

Biosphere 2 is an Earth system science research facility of the University of Arizona in Oracle, Arizona, north of Tucson, where a large glass-enclosed complex houses model ecosystems used for research, education, conferences and public tours. Built as a closed ecological system whose first sealed mission began in 1991, it has drawn more than three million visitors and over 500,000 school students since then, and the university now runs it for research, outreach and teaching. It employs research scientists, technicians, educators, tour guides and facilities staff who run its biomes, including a rainforest, an ocean, a desert and the Landscape Evolution Observatory.