A basement of mechanical systems—collectively called the technosphere—supports B2

Biosphere 2 is the largest Earth science experiment ever built

The vivarium—an enclosed system including animals and plants—is sealed from below with 454 metric tons of stainless steel liner and includes an ocean habitat with more than 700,000 gallons of seawater. B2 is visited by 100,000 people yearly, including more than 10,000 K-12 students.

An artificial ‘lung’ protects the glass structures making up Biosphere 2

Although confined from much of the surrounding environment, B2 allows sunlight to enter, enabling its plants to engage in photosynthesis. Expansion chambers were built to protect the facility's integrity by managing changes in gas pressure resulting from temperature fluctuations.

Before Biosphere 2, the Soviet BIOS-3 system tested semi-closed ecosystems

Built from 1965 to 1972, the habitat hosted 10 experiments with crews ranging from one to three individuals who had their air recycled by algae and grew their own wheat and vegetables. However, dried meats were routinely brought into the facility to balance crew members’ diets.

Biosphere 2 gradually transformed into a lab modeling environmental disasters

Built to establish a self-sustaining habitat, the privately funded facility was taken over by Columbia University in 1995. Closed-system experiments were halted in favor of investigations focused on the effects of climate change, which continued after B2 was donated to the University of Arizona in 2011.

Take a series of virtual tours of Biosphere 2

The videos provide a 360-degree view of the indoor rainforest, ocean ecosystem, Landscape Evolution Observatory, and underground technosphere. A Google Maps Street View option is available to explore additional biomes, with each associated with a different floor level on the bottom right.

Exposed concrete led to oxygen depletion within Biosphere 2

Instead of being absorbed by plants through photosynthesis to produce oxygen, significant amounts of carbon dioxide were taken up by the calcium hydroxide in the concrete, trapping the oxygen in calcium carbonate and water. This concrete was sealed before the start of the second B2 mission.

Biological terraforming studies have been conducted at Biosphere 2

The experiments involve populating barren hillslopes within the Landscape Evolution Observatory with microbes that react with air and rock to produce molecules needed by more complex organisms. Mosses and other simple plants can then grow in these spaces, gradually making them more hospitable to humans.

B2 models the interactions of air, water, soil, plants and microbes at the LEO

The Landscape Evolution Observatory at Biosphere 2 examines how factors such as climate change, water flow, weathering and community development impact landscape structures comprising 500 metric tons of crushed rock. Research is also conducted at biomes representing savannas, mangroves, coastal fog deserts, oceans and rainforests.

As an experiment, the first B2 mission highlighted the challenges of isolated systems

Some argue that isolation from the outside world was compromised—making the experiment a failure—when a crew member was taken from Biosphere 2 for surgery and returned hours later. This position was strengthened when it was revealed that oxygen had been pumped into the facility.

As of 2025, scientists at B2 study the heat tolerance of cacao and coffee trees

The research at Biosphere 2 has led to the development of low-cost plant monitors, which can be provided to farmers worldwide to enable more precise monitoring of crops. Geodesic domes built within the ocean biome are used to investigate the best architectural structures for repopulating degraded reefs.

During the first Biosphere 2 mission, crew members lost 16% of their body weight

Food and oxygen shortages drove the "Biospherians" to split into two factions—one seeking to bring in outside resources and another aiming to maintain isolation for the experiment's integrity. Psychological stress was exacerbated further by the increasing prevalence of insect pests.

Data centers require interconnected server- and building-level cooling systems

Computer equipment can be cooled by circulating cold air or water through the equipment racks, siphoning the heated fluid into a heat exchanger. This exchanger transfers thermal energy to building cooling systems, which can dispose of the heat by evaporative cooling—the way humans cool off by sweating—or via air conditioning.

A prototype greenhouse for Biosphere 2 is now part of a test habitat for Mars

The Space Analog for the Moon and Mars combines the Test Module greenhouse with a workshop, kitchen, common area, sleeping quarters, and a yard that mimics lunar and Martian surfaces. A blind crew member in SAM’s first mission, Inclusion I, helped assess accessibility in potential future space habitats.

Aquifer thermal energy storage systems bank water heated during the summer in aquifers—layers of porous rock, gravel, and sand filled with groundwater—which are then collected in winter to warm homes.

View the layout and components that make up a typical data center

Alongside server rooms for the storage, processing, and transmission of data, data centers include climate control systems to manage the heat generated by microchips, backup systems to ensure systems can run during power outages, offices for on-site personnel, and monitoring and security stations to provide continuous protection against physical threats.

Agrivoltaic solutions are tested in the land around the Biosphere 2 complex

The experiments involve identifying conditions needed to grow plants beneath solar panels, which protect the plants from the harsh sunlight of the Arizona desert. Research includes a citizen science component, where satellite gardens have been installed in nearby high schools.

Cooling each square foot of a room requires at least 20 BTUs of capacity

British thermal units describe the cooling capacity of air conditioners, though noise levels, directional airflow, and filtration also affect their effectiveness. Insufficient BTUs are unlikely to cool a large enough room faster than the environment warms the air.

Thermodynamics makes building data centers in space to cool equipment impractical

Rather than cooling via interactions with flowing cold air or water, data centers in space would dissipate energy primarily by radiation, in which an object at any temperature above absolute zero emits light. This method is much less efficient at cooling and would require hyperscale data centers to have radiator panels thousands of times larger than those on the International Space Station.

Steve Bannon was made CEO of the company in charge of Biosphere 2 in 1994

After providing $200M to launch and upgrade B2 before its second mission, billionaire philanthropist Ed Bass appointed the future political strategist and then financial consultant to help find new investments and bring costs under control. Fearing interference from non-science experts, Biospherians from the first mission vandalized the project.

Biosphere 2 revealed limitations in maintaining wildlife in unfamiliar environments

Trees appeared to become weak and more prone to breaking because a lack of wind caused them to no longer need to develop stress wood. The extinction of pollinators—potentially due to an explosion in the population of longhorn crazy ants—was also unexpected.

Since 2026, the Large Hadron Collider has provided heat to thousands of French homes and businesses through a system that harnesses hot water from the accelerator's cooling circuits.

Inhabiting Mars without terraforming might be accomplished with 'worldhouses'

A network of interconnected, airtight bubbles would require several orders of magnitude fewer materials than those required to re-establish the entire planet's atmosphere to resemble Earth. However, the whole network would be compromised by a single micrometeor impact that destroys the air seal.

When users prompt AI chatbots, both cooling systems that support data centers and power plants that rely on steam cycles to generate electricity for data centers contribute to water use.

Watch a time-lapse of the construction of a data center

After the external structure of a data center is built, cooling systems are installed, followed by interior offices and other rooms. Before installing racks of servers and other equipment, floors are raised beneath where they will be installed to create space for cold fluid to be pumped into the hardware and to facilitate cable management.

According to the International Energy Agency, hyperscale data centers consume about as much electricity annually as 400,000 electric vehicles to provide 24/7 access to online applications, services, and information.

Some geothermal power plants make electricity using a secondary fluid

Direct dry-steam systems pull underground steam into a turbine-generator system, while flash and double-flash cycle systems spray extracted liquid water into a low-pressure tank, causing it to rapidly vaporize—"flash"—before moving to the turbine. Binary cycle systems use the extracted steam and water to flash a second fluid that easily boils, which then drives the turbine.

Read a firsthand account of a participant in the first Biosphere 2 mission

The first crew of “Biospherians” spent four months growing their own wheat and awaiting the ripening of tomatoes, onions, and peppers to make their own pizza. They also raised their own livestock, including chickens, pigs, and two goats named Milky Way and Stardust.

Sand 'batteries' can store excess electricity from the power grid as thermal energy

Energy collected from solar or wind power is used to heat insulated silos full of sand to temperatures as high as 450 degrees Celsius (842 degrees Fahrenheit), which can be retained for long periods. These thermal energy storage systems can be designed to boil water and generate electricity when needed.

Data centers can be kept cool by circulating fluid over plates atop high-temperature components or by submerging equipment in non-corrosive oil that does not conduct electricity.

Geothermal power can generate electricity and provide direct heating for homes

By drilling several kilometers through penetrable rock, wells can access highly pressurized groundwater warmed by thermal energy trapped beneath Earth's surface. This water can be turned into steam to create electricity in generators. Heating systems several meters deep can pump fluid underground before circulating it through buildings.

Explore a gallery of Bill Nye's energy-efficient home

The Southern California home is painted pale yellow and features double-pane, low-emissivity glass windows to help keep temperatures low. Solar panels are used for electricity and hot water, while Solatube domes and ducts illuminate rooms from above throughout the day, even when the sun is low in the sky.

Human anatomy 101: the body's systems

Human life is made possible by the body's ten major systems, which maintain homeostasis by responding to incoming sensory and biochemical input. Each system must work independently and collaboratively for the body to maintain health and respond appropriately to its internal and external environments. The bones of the skeletal system, for example, give the body its shape and protect organs while also facilitating movement with the muscular system.

Geothermal power plants can provide large-scale energy storage for other systems

These facilities can store excess energy from solar and wind power as hot water or steam, which can be used to run turbines to generate electricity when other renewable energy sources are unavailable. Simulations have found efficiencies of 90% during a storage-use cycle, making it comparable to lithium-ion batteries.

Since 2022, two-thirds of data centers have been built in water-stressed areas

In residential evaporative cooling systems, 10% of consumed water is lost to evaporation compared to 80% in data centers. Although some companies have pledged to become water-positive—replenishing more freshwater than they consume—by 2030 through a transition to air cooling, only 10% of data center operators track water use across all their facilities.

While carbon capture and storage systems collect carbon dioxide at the source, such as power plants, direct air capture systems extract it from the atmosphere.

Learn how environmental conditions are optimized to increase bioremediation efficacy

Through biostimulation, Indigenous microbes are provided with moisture, nutrients, or oxygen to prevent their death and ensure optimal progression of their biochemical reactions. Bioaugmentation can introduce new microbial cultures to target specific compounds not natively found in the environment, while landfarming can spread or aerate contaminated soil to improve access to contaminants.

Astronauts on the International Space Station have tested an algae-powered bioreactor that converts carbon dioxide, water, and light into oxygen and edible, protein-rich biomass.

Research suggests AI data centers may be creating microclimate heat islands

An analysis of satellite data from 2004 to 2024 showed that land surface temperatures in the areas surrounding AI data centers typically increase by an average of 2 degrees Celsius (3.6 degrees Fahrenheit) after they begin running. Across the 6,000 global data centers analyzed by the study, temperatures increased by as much as 9.1 degrees Celsius (16.4 degrees Fahrenheit).

An overview of Earth's atmospheric cells and how they distribute Earth's uneven heating

The Hadley, Ferrel, and Polar cells are circulation patterns that act like gears, moving warmer air from the equator to the poles. The rising and falling of air currents within these patterns creates semi-persistent regions of low and high pressure, which contribute to the formation of regional climates, such as tropical zones.

Comparing bioremediation with other treatment techniques, at three levels of complexity

Physical manipulation, such as collecting and moving contaminated material to a landfill, or chemical applications, which use strong, expensive substances and produce harmful byproducts, can be costly. While bioremediation leverages naturally occurring degradation processes that can be augmented without disrupting impacted ecosystems, these processes may be less effective in environments that bioremediation organisms are not adapted to.

The history of Earth's breathable atmosphere, made possible by photosynthetic bacteria

Between 3.2 billion and 2.8 billion years ago, threadlike microorganisms called cyanobacteria began consuming available water vapor, carbon dioxide, and sunlight to produce oxygen. However, molecules released from Earth's interior by volcanoes consumed this oxygen via chemical reactions, preventing it from accumulating until volcanism had sufficiently decreased about 2.4 billion years ago.

The Large Hadron Collider is the world's largest cryogenic system, which uses 10,000 metric tons of liquid nitrogen and 120 metric tons of helium to cool 36,000 metric tons of magnets to temperatures colder than outer space.

Heat pumps use an easily boilable chemical to regulate temperature

In air conditioners, warm air is pulled from a home to turn a refrigerant into a gas, which is then compressed, raising its temperature. The gas naturally releases this energy to the comparatively cooler environment when exposed, then expands and is reused in the system. Heaters run in reverse, with the refrigerant picking up energy from the comparatively warmer environment.

Home energy performance can be boosted through home orientation and shading

When designing a home, placing living areas to the north maximizes sun exposure during winter, while eaves and awnings can limit excessive summer heat. Breezeways and entry air locks can also reduce the dependence on heating and cooling costs.

China developed an artificial closed ecosystem in preparation for a future lunar base

Yuegong-1, also known as Moon Palace 1, was a Beijing facility where volunteers simulated life on a colony and conducted experiments on bioregenerative life support systems to assess their viability in an off-Earth environment. The longest experiment at the 0.04-acre facility lasted 370 days.

A breakdown of Earth's atmospheric layers, including why it can get colder or hotter with altitude

Gases in the troposphere—the atmosphere's lowest layer—cool with increasing height as they get farther from the thermal energy emitted by Earth's warm surface. In the next layer—the stratosphere—ozone is increasingly heated by the sun's ultraviolet radiation with height. Because cooler air sinks and hotter air rises, the cooler troposphere and hotter stratosphere form a natural boundary keeping Earth's weather in the lowest layer.

The setting of the comedy film ‘Bio-Dome’ was inspired by Biosphere 2

The film features characters played by Pauly Shore and Stephen Baldwin who accidentally lock themselves inside an experimental biosphere, mistaking it for a shopping mall, while searching for a bathroom. With a Rotten Tomatoes score of 4%, it is considered one of the best-worst movies of all time.

The warmest waters in the ocean are found at hydrothermal vents—hot springs on the seafloor that discharge plumes of mineral-rich water.

Oxygen is produced in the International Space Station from recycled water, which is split into hydrogen and oxygen gases using an electric current.

Enhanced geothermal power systems can trigger earthquakes by injecting fluid into rock, increasing subterranean pressure.