Margaret D. Andrews
Scientists have built a miniature earth in Oracle, Arizona. They have created a 2.5 acre, self supporting environment enclosed by glass and steel called Biosphere 2. Students will learn about Biosphere 2, the largest totally sealed environment in the world, and will design and conduct their own experiments with mini-environments. In the process, they’ll discover facts about the delicate balance of nature and the environment.
A biosphere is a region where life can exist. It must have everything a living organism needs to survive. Scientists call earth “Biosphere 1,” likening it to a cocoon. In this cocoon, plants and animals live together in a fragile, life-supporting balance.
Biosphere 2 is the largest totally sealed environment in the world. Closed to the air by a double pained glass dome and sealed off from the soil by a stainless steel underground plate, Biosphere 2 encompasses six geographical regions having different climates, plants, and animals. These regions known as biomes, include a rain forest, a savannah, a salt water marsh, a fresh water marsh, an ocean, and a desert. Biosphere 2 houses plants, animals, even people.
You might think that animals would die and plants would dry up in a closed environment. But that won’t happen if the right balance is maintained. If more nutrients are constantly generated for food production, and the water supply and atmosphere are constantly regenerated, the environment will continue to sustain life.
Biosphere 2 will give environmental scientists their first opportunity to work with a control. Using a control, scientists can compare what happens in a normal situation to what happens in a test situation. Because Biosphere 1 (earth) is regularly exposed to and tested by pollution, oil spills, toxic waste, droughts, floods, and so on it will be the test environment in this experiment. Biosphere 2 is the control environment because it is sealed.
By designing, building, controlling, and monitoring life in Biosphere 2, scientists hope to learn more about earth’s ecological balance and how we can protect it. Someday, this mini-world might also be the model scientists use to build habitats for people on the Moon or on Mars. When choosing the occupants of Biosphere 2, scientists imitated nature. For example, some plants and animals were carefully chosen to create food chains. Others were selected because of the jobs, like pollination, they perform.
A permanent population of lady bugs and praying mantises, for example will take the place of pesticides.
Technology assists nature in Biosphere 2. Computer operated shutters control temperature and sunlight. In all, nearly 2,000 computer sensors constantly monitor conditions in Biosphere 2. Should nature need an assist, the computers regulate adjustments to air pressure, air temperature, air circulation, and water supply. Water, air, and waste are recycled.
In September, eight scientists joined more than 3,000 different types of plants and animals for a two year stay in Biosphere 2. The four men and four women will grow grains, fruits, and vegetables and will raise animals and fish.