ORACLE,- SEPTEMBER 25: ORACLE, USA - SEPTEMBER 25: The Biosphere 2 research facility sits nestled in the foothills of the Catalina Mountains north of Tuscon, Arizona 25 September 1993. The eight inhabitants of the Biosphere will step out of the sealed structure early 26 September as they complete their two-year ecological research experiment. (Photo credit should read TIM ROBERTS/AFP via Getty Images)
