The terrarium Biosphere 2 is to become a research conversation piece for a new housing development in Arizona.

Tourists still flock to the desert complex that once housed an experiment in self-sustainability. Credit: PRN/NEWSCOM

Last week, the 1.4-hectare glass enclosure and about 700 hectares of land around it in the desert foothills outside Tucson were sold for US$50 million. Its new owner, CDO Ranching & Development, is securing permits to build 1,500 houses around the edifice.

The University of Arizona in Tucson is negotiating with the new owners to lease the facility for climate experiments.

Texas oil billionaire Ed Bass spent about $200 million on the project. In 1991, the glass bubble became the centre of worldwide attention when eight people were sealed inside for a two-year 'experiment' in self-sustainability. But the project failed — oxygen had to be pumped in from outside, and the experiment ended early amid much squabbling both inside and outside the bubble.

By 1996, Columbia University in New York City had taken over managing the facility. It planned extensive research projects on climate, soil and plant dynamics. But Columbia withdrew from the arrangement at the end of 2003 as part of a litigation settlement with the facility's corporate owner, Decisions Investments.

The University of Arizona had been negotiating for several years to attempt to buy the Biosphere 2 complex, now largely used for tours by the curious. Local politicians also want it preserved as it as a landmark that attracts tourists.