Biosphere

The biosphere is the worldwide sum of all ecosystems. It is the zone of life on the Earth. It includes every living thing and how they interact with the air, water, land, and ice.

The biosphere is like a huge, round shell that surrounds our planet. It is a closed system for matter, meaning that what goes in mostly stays in, but it is open for energy. Plants use photosynthesis to capture solar energy, which powers almost everything else in the biosphere.

Biospheres can also be made by people. For example, there have been artificial biospheres like Biosphere 2 and BIOS-3. Scientists also wonder if other planets or moons might have their own biospheres. The Earth's biosphere is thought to have begun at least 3.5 billion years ago, when simple life first appeared.

Origin and use of the term

The word "biosphere" was first used in 1875 by a scientist named Eduard Suess. He described it as the part of Earth's surface where life exists.

Later, other scientists added to this idea. In the 1920s, a scientist named Vladimir I. Vernadsky helped explain how living things and Earth work together. He saw ecology as the study of the biosphere. Today, the biosphere includes all living things and how they connect with Earth’s air, water, and land.

Earth's biosphere

The biosphere is the worldwide sum of all ecosystems on Earth. It includes every living thing, from tiny microbes to large animals, and exists in many different places, from the coldest polar ice caps to the warmest parts near the equator.

Life exists almost everywhere on Earth. Microbes live deep underground and high in the atmosphere. Some animals, like yaks and mountain goats, live on very high mountains, while others, like fish, live in the deepest parts of the ocean. Even in extreme conditions, such as very hot or very cold places, life can be found. The biosphere is divided into different areas called biomes, each with its own kinds of plants and animals.

Artificial biospheres

Scientists have created special experimental environments called closed ecological systems to learn more about how ecosystems work and how life might survive beyond Earth. These include areas designed to mimic natural conditions and support plants, animals, and microorganisms.

Some famous examples are Biosphere 2 in Arizona, United States, covering 3.15 acres (13,000 m²); BIOS-1, BIOS-2, and BIOS-3 in Krasnoyarsk, Siberia, in what was then the Soviet Union; Biosphere J (CEEF) in Japan; and the Micro-Ecological Life Support System Alternative (MELiSSA) at the Autonomous University of Barcelona.

Extraterrestrial biospheres

No biospheres have been found beyond Earth, so the idea of biospheres on other planets is still just a theory. Some think they might be very rare, especially if they can only support very simple life like tiny microbial organisms. However, there may be many Earth-like planets, especially in our Milky Way galaxy, because there are so many planets out there. Scientists have found three planets around a star called TRAPPIST-1 that might have biospheres.

Scientists using the Kepler Space Telescope have estimated that if the chance of life starting is better than 1 in 1000, the nearest alien biosphere could be within 100 light-years of Earth. In the future, people might even create artificial biospheres, for example by changing the surface of Mars to support life.