Save Save Remove Delete Biosphere 2, a science research facility in Oracle, Arizona, now owned by the University of Arizona. It is a center for research, outreach, teaching, and lifelong learning about Earth, its living systems, and its place in the universe. Originally built to be an artificial, materially closed ecological system, or vivarium, it remains the largest closed system ever created. Original image from Carol M. Highsmith’s America, Library of Congress collection. Digitally enhanced by rawpixel. MoreFree public domain CC0 imageEditorial use onlyID : 582397 Jpeg Web size Jpeg 1200 x 873 px | 300 dpi Large size Jpeg 3500 x 2548 px | 300 dpi Original size Jpeg 7059 x 5139 px | 300 dpi View license We've made this image available to the public domain providing everyone access with a CC0 license.Free for personal and commercial use.No attribution required.