First Visit to Biosphere 2

John had to work, and Rachel was enjoying a visit from her mother; but the rest of us crammed into the SUV and took the short route from our house east on US 60, then south on AZ 79. Except for passing through the town of Florence, whose claim to fame is a huge prison facility, the road cut arrow-straight through the beautiful desert. Had the drive taken more than an hour, it might have grown boring no matter how beautiful it was. But '80s rock 'n' roll kept us occupied and soon we reached AZ 77, just a couple of miles from our destination. As we drove southward, the ramparts of Mount Lemmon loomed before us (another place I'd like very much to visit—but that will have to wait for another trip). It was very much in sight, however, bordering the steep valley in which Biosphere 2 is located.

When Edward Bass decided to build Biosphere 2 with his then-friend John Allen, they chose this spot primarily because it receives 300 days of sunlight a year.

A biosphere is a closed system into which only sunlight enters, and which supports life. Except for sunlight, everything else is recycled. "Biosphere 1" is Earth.

Biosphere 2 is Bass and Allen's experiment, a $150 million greenhouse or terrarium designed to be a closed system into which only sunlight can enter, and in which everything else would be recycled. The question was: Can we, in fact, construct such a closed system? We might have to if we want to visit Mars. We would certainly have to in order to visit other stars, because it simply wouldn't be possible to pack enough food for a centuries-long trip. Even just going to Mars would take two years, one-way. So the original experiment included eight people, four men and four women, who would voluntarily enclose themselves in Biosphere 2 and live, materially cut off from the outside world, for two years.

Biosphere 2 is the largest greenhouse ever built, covering over three acres and measuring 7,000,000 cubic feet in volume. Its thick concrete base is covered by a solid steel, custom-welded liner to keep out contaminants such as radon gas from entering. (However, the liner failed to keep carbon dioxide in, which was another issue.) Studies have shown the sealing of Biosphere 2 is so complete that it only leaks about 6% a year—compared to the Space Shuttle, which loses 350% of its atmosphere over the course of a year.

To take a tour of the interior of Biosphere 2 costs $20 for adults and $12 for kids Zachary's age. When I paid for the tour, I was warned—repeatedly and intensely—of the number of steps we would have to navigate. There were a number of steps, but nothing like one finds at Walnut Canyon.

The tour begins in the "Human Habitat", which is within the seal and is where the members of the original two-year mission (and the six-month mission that followed) lived. Most of the apartments have since become offices, but one has been retained "just as it was originally" so we can see how the Biospherians lived. It seems charming, in an Ikea sort of way.

While the apartments and laboratories are interesting enough, one visits Biosphere 2 to see the terrarium.

Indoor ocean: Actually contains a section of coral reef and sea water transported from the Western Caribbean. Wave machines help keep the water oxygenated."

Karen stares in disbelief at the rain forest hanging over the ocean, while Arizona's Sonoran Desert hovers on the far side of the glass.

The bulk of Biosphere 2 is divided by plastic curtains into biome habitats that mimic various parts of Earth's ecology. There's a rain forest, a fog desert, upper and lower savannahs, and a thorn scrub, not to mention an actual ocean—or, at least, a section of coral reef. A huge banana tree dominates the entrance (this tree provided the majority of the human missions' meals) but it's quickly forgotten as you look over a sheer cliff into the "ocean", while rain drenches the rain forest above.

What happens when trees face drought? Enquiring graduate students want to know.

The sections of Biosphere 2, which are now used for non-closed research, can be adjusted to mimic the temperature and humidity of any biome on Earth.While we were there, one section was being adjusted for an experiment in which pines would be studied to see exactly what happens to them in a drought.

In the fog desert, mimicking a stretch of land along the Mexican Pacific coast, stretches of gray and brown brambles made Michael ask why all the plants there were dead. "They aren't dead," our guide explained. "They are just dormant. In nature, in the winters fog brings these babies back to life and they produce prodigious amounts of oxygen. We can't keep them in fog all the time, though; it would stress them out too much."

Zach listened carefully to the tour guide.

Oxygen, or the lack of it, was the major cause of stress during the first two-year "mission". Microbes in the soil multiplied more exuberantly than expected, and they sucked in much of the oxygen the humans had expected to breathe. The microbes emitted carbon dioxide, of course; and normally that would have been absorbed by the plants and recycled back into oxygen. What no one expected was that the porous concrete foundation of the place, despite the steel seal, absorbed enough of the carbon dioxide to throw off the balance.

The lack of oxygen caused obvious problems for the crew as well as subtle ones. They found themselves headachy and short-tempered. Life-long friends became implacable enemies. The crew of eight split into two factions. All that was missing was Mark Burnett and a camera crew. Finally, oxygen had to be piped into the "closed" system, on two occasions.

The area beneath the terrarium is, in its way, as interesting as the terrarium itself. It shows the lengths to which man will go in order to try and mimic nature. Miles of piping move chilled, cool and hot water from place to place to create the precise temperatures needed in each section of the terrarium. The energy required to maintain these temperatures, not to mention moving the air and water around, comes from an "energy complex" that creates electricity from LP gas generators, as well as from the state power grid and a smattering of solar panels located haphazardly here and there.The sun shining through the acres of glass panels creates more problems, which engineering was able to accommodate. Specifically, as the air inside heats, air pressure increases. That air has to go somewhere; and in a closed system there's nowhere for it to go. So Biosphere 2 needed a "lung" that would expand and contract as needed.

The "lung" is a cavernous space in which the ceiling is actually a rubber gasket. When the air pressure rises in the morning, the bladder-like gasket rises. When the air pressure goes down in the evening, so does the gasket.

Jenny ponders the absorption of carbon dioxide into concrete and how that formed calcium carbonates in an unexpected place.

While there is a lot of controversy over how much actual science was done during the first few years of Biosphere 2's existence, there can be no argument that the place is a triumph of engineering. During the initial two-year mission, the number of things that didn't go wrong is astounding. If Microsoft Vista were as well-engineered, there'd be no complaints about it. True, the problem with the oxygen was nearly a show-stopper. But we now understand that a more expensive foundation of aluminum would not have had the CO₂ absorption issues. So real science was done: A theory was tested, and as a result our understanding of the Universe increased.One of Biosphere 2's strongest points was that its designers understood that life and the environment are inextricably linked. When we hear astronomers talk about planets "suitable to life" we are being misled. No planet, including Earth, was "suitable for life" before it had life. In an intricately choreographed ballet, life shapes a planet even as the planet shapes its life. As planetary scientist, Dr. David Grinspoon, pointed out: "Earth wouldn't have 'Earth-like' conditions without life, because life has shaped the world we know. For instance, photosynthetic organisms created the oxygenated atmosphere, as well as the ozone layer that protects us from the Sun's most destructive rays. So to say another planet must be Earth-like in order to support life is to put the cart before the horse. Instead, a planet must support life in order to be Earth-like…I suspect that life can only survive on a planet for billions of years if it has become deeply embedded in the geochemical, physical, and climatic cycles of that planet in a way that stabilizes the environment.

"That we could ever re-create an earthlike environment in a closed space is unlikely, because an earthlike environment, by definition, requires an Earth.

To replace any component of the environment with machinery requires a complete understanding of both the component and the machinery. It took the Earth 3 billion years to work out all the kinks, and even now Earth seems to have underestimated the impact one of her species (humanity) can have on the total balance.

As costly as that understanding may be to gather, though, I do applaud the effort. Even though the terrarium is now open to the atmosphere, research projects go on that don't require an enclosed and limited atmosphere. Researchers can occupy a nearby village instead of having to live "under the glass". Biomes can be used, discarded, rebuilt as the science requires. Biosphere 2 is truly a priceless, one-of-a-kind test tube in which our world can be studied, and yet another gem in Arizona's tiara.