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A Tour of Biosphere 2 in Oracle, Arizona

I've lived in Flagstaff, AZ, since 2003, where I'm an active member of the Coconino County Sheriff's Search & Rescue team and an avid hiker.

Biosphere 2

Biosphere 2

A couple of years ago, on a road trip around southern Arizona without an itinerary, my husband and I made a spontaneous stop at a place called Biosphere 2 near a town called Oracle.

I'd heard of Biosphere 2 many years earlier in college while studying Environmental Conservation, but I didn't recall the details. Just something about a group of people sealing themselves inside the place for two years. So as primary navigator on our adventure, when I saw "Biosphere" on the map, I suggested we make a stop and see what it was all about.

And we were glad we did, what a fascinating place. Biosphere 2 is a glassed-in world of mangrove wetlands, tropical rainforest, savanna grassland and coral reefs in the middle of the Sonoran Desert.

The Original Biosphere

The Original Biosphere

What is Biosphere 2?

Like Earth Under Glass

Biosphere 2, constructed between 1987 and 1991, was used to study the interactions within life systems and explore the potential use of closed biospheres for space colonization. The facility allowed scientists and students to manipulate a biosphere without harming the Earth, and to monitor the chemistry of the air, water and soil inside. Biosphere 2 was the largest closed system ever created.

The basement area of Biosphere 2, called the "Technosphere," is where all the electrical, plumbing and mechanical systems are housed. Included are 26 air handlers that heat and cool the air, remove particles, maintain humidity levels, and generate and condense water for rain and fog and to resupply the man-made ocean.

The building with the arched segments and three towers seen in the picture above is the Energy Center. Biosphere 2 requires continuous power to maintain proper conditions for the living organisms inside and for ongoing experiments.

Given Biosphere 2's location in the Sonoran desert, with daytime summer temperatures often reaching into the 90s and sometimes triple digits, a power failure on a sunny day would irreparably damage -- that is, cook -- the plants inside the facility within twenty minutes. But a large generator maintains power and controls the biomes during the frequent outages during monsoon season.

The primary generator inside the Energy Center is fueled by natural gas, while a back-up generator runs on diesel. In addition to the generators, there are boilers for heating water and chillers for cooling it. The large towers are used to cool air by drawing it across a column of water.

Between 1991 and 1994, two missions sealed Biospherians inside the glass enclosure to study survivability. These were very public experiments but also very useful, furthering our understanding of ecology.

The University of Arizona assumed management of Biosphere 2 in June, 2007.

Biosphere 2: A Visitor Poll

Interesting Facts About Biosphere 2

  1. Biosphere 2 is a 3.14-acre facility on a 40-acre campus.
  2. It has 7,200,000 cubic feet of sealed glass.
  3. The main enclosure is 91 feet at its highest point.
  4. The facility is sealed from below by a 500-ton welded stainless steel liner.
  5. Biosphere 2 has 300,000 sq. ft. of administrative offices, classrooms, labs, conference center, and housing.
  6. The elevation of Biosphere 2 is 3,820 feet.

From the official website, by the University of Arizona.

Tour Biosphere 2

Tour Biosphere 2

The Guided Tour

It's Well Worth the Price of Admission

My husband and I hesitated at the $20 per person cost of the tour (discounted rates are offered to AAA members, seniors, kids and military), though half the fee goes to support research at Biosphere 2 and qualifies as a tax-deductible contribution. But we were in vacation mode, so we went ahead with it. And we weren't sorry. It was lengthy tour, informative and fun, well worth the money. We also enjoyed exploring the grounds after the guide departed.

The tour begins in the human habitat area, where you'll see one of the apartments where the "Biospherians" lived, the farm where they grew their crops and the kitchen where they prepared their meals.

You'll then enter the wilderness areas through the airlock door, where you experience the various environments inside Biosphere 2, beginning with the tropical savanna.

The trail system works its way along the 40-foot ocean cliff where you can look down into the million-gallon tropical ocean. As you move along, you descend into the lower savanna along the mangrove wetlands, through the tropical thorn scrub and into the coastal fog desert.

From the desert, you enter the "technosphere," where mechanical systems control the Biosphere 2 environments. From the technosphere, you make your way into the tropical rainforest which contains over 150 different species of plants, some more than 60 feet tall.

Finally, you descend through a tunnel into one of two "lungs." The lungs are large geodesic domes that originally prevented Biosphere 2 from exploding or imploding.

I also remember seeing the ocean from below, through large windows.

These guided tours are given throughout the day. And group and school tours can also be arranged. Call (520) 838-6200 for more information and reservations of groups of 20 or more.

View of the Ocean in Biosphere 2

View of the Ocean in Biosphere 2

The Human Experiments

There Were Two at Biosphere 2

The first closed mission, which lasted from September 26, 1991, to September 26, 1993, included a crew of 8 researchers and a medical doctor. This mission was fraught with problems. Or challenges, rather.

For one, oxygen inside the facility fell steadily and, after 16 months, had decreased 14.5%, to a level equivalent to the oxygen available at an elevation of 18,000 feet. The doctor closely monitored oxygen levels and consulted with doctors on the outside. Eventually, he requested that pure oxygen be pumped in, and two more injections were needed after that.

Apparently, this issue was caused in part by low light levels. The weather that year was unusually overcast, which reduced photosynthesis. Not to mention that the structure's support beams also blocked a significant amount of light.

Many suspected the oxygen drop was due to microbes that had been added to the soil in the savanna, rain forest, and agricultural sections to aid plant growth. And the amount of carbon installed in the soil at the beginning of the experiment was too high. Scientists believed that these microbes were consuming too much oxygen from the air and converting the carbon in the soil into carbon dioxide.

One problem critics of this theory cited was that microbes breathing that much oxygen would also create a huge amount of carbon dioxide. So the increase in CO2 would have been greater than what was detected. More investigation revealed that the concrete throughout the facility was absorbing the oxygen because it had not fully cured. This allowed for a marked drop in oxygen levels without a significant rise in carbon dioxide.

Biosphere 2 also suffered from wildly fluctuating CO2 levels, and most of the vertebrates and all of the pollinating insects died. Ants were purposely introduced since they were a companion to one of the tree species in the rain forest. But by 1993, a species local to the area, which had been unintentionally sealed in, dominated.

Another problem reported by the nine Biospherians was continual hunger. While some crops, like bananas, peanuts and sweet potatoes, grew well, the very active inhabitants weren't able to grow enough food to satisfy their appetites.

The second closed mission with seven crew members began on March 6, 1994, with an intended ten-month span, but it ended prematurely six months later. During that time, a dispute amongst the management team led to the ousting of the on-site management by federal marshals and the issuance of a restraining order. And as juvenile as it sounds, in the wee hours of the morning on April 5th, 1994, two members of the first mission's crew deliberately vandalized the project, opening all doors and violating the enclosure. Soon after that, the captain of the team left.

Watch a video interview of the first closed mission, as Jane Poynter, author of The Human Experiment, describes her two years and twenty minutes inside Biosphere 2.

The Human Experiment - Footage From Inside Biosphere 2 1991-1993

Who Is John Allen?

Talk About a Busy Man...

Born in 1929, John Polk Allen is the inventor and co-founder of the Biosphere 2 project.

Allen's extensive resume also includes his role as the former Executive Chairman and Director of Biospheric Research Development & Engineering for Space Biospheres Ventures.

He co-founded and, until 2006, served as Chairman of the Planetary Coral Reef Foundation, a non-profit devoted to monitoring the health and vitality of coral reefs, and exploring the origins of human cultures aboard the Heraclitus, a special research vessel he invented in 1974. The Heraculitus has sailed over 200,000 nautical miles around the world.

Currently the Chairman of Global Ecotechnics Corporation, John Allen designs a second generation of materially closed, biospheric and ecologically enriched biomic systems.

Allen studied anthropology and history at Northwestern, Stanford, and Oklahoma Universities, and served in the U.S. Army's Engineering Corps as a machinist. He graduated from the Colorado School of Mines and received an MBA from the Harvard Business School.

On top of all that and more, the prolific John Allen has written novels, poetry, short stories and plays under the pen name, Johnny Dolphin.

More About Little Oracle, Arizona, Home of Biosphere 2

Population 3,932 (as of 2020)

Located 38 miles from downtown Tucson, Oracle is one of the communities that make up Pinal County, Arizona. Aside from being the home of Biosphere 2, Oracle was the also official home of environmentalist author Edward Abbey. Another well-known resident was Buffalo Bill Cody, who owned a mine there for a short time and built a house. The area is also known for its outdoor recreation, like great hiking, mountain biking and horseback riding in the 4,000-acre Oracle State Park.

Other things to do in Oracle include:

  • The Oracle Run, a 6.2 mile run over steep and hilly terrain, held every year on a Saturday close to Halloween
  • The Calabazas (Pumpkin) Festival, held every year in October at Oracle State Park
  • GLOW, an evening of art and music held one weekend in the fall

    at Triangle L Ranch by the light of the full moon

  • The Oracle Oaks Festival and Oracle Car Show, held every year in the spring to benefit the Community Center and the Oracle Historical Society

For more information on this rockin' town, visit the Community Guide to Oracle, Arizona.

Biosphere 2 is near Oracle, Arizona

Biosphere 2 is near Oracle, Arizona

Driving Directions to Biosphere 2

From Central Tucson:

*Go north to River Road and turn left (heading west).

*Continue on River Road and turn right (north) on Oracle Road (Arizona Highway 77).

*Continue north approx. 24 miles on Oracle Road/Highway 77, to Biosphere 2 Road at Mile Post 96.5, and turn right.

Google Map from Tucson to Biosphere 2

From Phoenix Sky Harbor International Airport:

*After leaving the airport, follow the signs to Interstate 10 East.

*Take I-10 East, toward Tucson, to Exit 185 and exit the interstate.

*Turn left onto Highway 387 and continue past Coolidge until Highway 387 intersects with Arizona Highway 79 near Florence.

*Turn right on to Highway 79 and follow this until Oracle Junction where you turn left onto Arizona Highway 77.

*Drive 6 miles to the Biosphere 2 turnoff, located at Mile Post 96.5. Turn right on Biosphere Road.

Google Map from Phoenix Sky Harbor Airport to Biosphere 2

Finding Oracle

Questions & Answers

Question: What is the internal temperature of Biosphere 2?

Answer: I don't know the specific answer to that, but I do know the temp varied in the different biomes--some cooler, some warmer, some humid, others dry-- which makes sense of course. The living areas for the scientists were a very comfortable temperature, but I don't knoe if they could each regulate a thermostat in their own areas.

© 2009 Deb Kingsbury