The biosphere (), also called the ecosphere (), is the worldwide sum of all

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

s. It can also be termed the zone of

life Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, met ...

on the

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

. The biosphere (which is technically a

spherical shell In geometry, a spherical shell (a ball shell) is a generalization of an annulus to three dimensions. It is the region of a ball between two concentric spheres of differing radii. Volume The volume of a spherical shell is the difference between ...

) is virtually a closed system with regard to matter,"Biosphere"
in ''The Columbia Encyclopedia'', 6th ed. (2004) Columbia University Press. with minimal inputs and outputs. Regarding

energy Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...

, it is an open system, with

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

capturing

solar energy Solar energy is the radiant energy from the Sun's sunlight, light and heat, which can be harnessed using a range of technologies such as solar electricity, solar thermal energy (including solar water heating) and solar architecture. It is a ...

at a rate of around 100

terawatts The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named in honor o ...

. By the most general biophysiological definition, the biosphere is the global

ecological Ecology () is the natural science of the relationships among living organisms and their environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels. Ecology overlaps with the closely re ...

system integrating all living beings and their relationships, including their interaction with the elements of the

lithosphere A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time ...

cryosphere The cryosphere is an umbrella term for those portions of Earth's surface where water is in solid form. This includes sea ice, ice on lakes or rivers, snow, glaciers, ice caps, ice sheets, and frozen ground (which includes permafrost). Thus, there ...

hydrosphere The hydrosphere () is the combined mass of water found on, under, and above the Planetary surface, surface of a planet, minor planet, or natural satellite. Although Earth's hydrosphere has been around for about 4 billion years, it continues to ch ...

, and

atmosphere An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

. The biosphere is postulated to have

evolved Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

, beginning with a process of biopoiesis (life created naturally from matter, such as simple organic compounds) or

biogenesis Spontaneous generation is a Superseded scientific theories, superseded scientific theory that held that living creatures could arise from abiotic component, non-living matter and that such processes were commonplace and regular. It was Hypoth ...

(life created from living matter), at least some 3.5 billion years ago. In a general sense, biospheres are any closed, self-regulating systems containing ecosystems. This includes artificial biospheres such as and , and potentially ones on other planets or moons.

Origin and use of the term

The term "biosphere" was coined in 1875 by geologist

Eduard Suess Eduard Suess (; 20 August 1831 – 26 April 1914) was an Austrian geologist and an expert on the geography of the Alps. He is responsible for hypothesising two major former geographical features, the supercontinent Gondwana (proposed in 1861) and ...

, who defined it as the place on

Earth's surface Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

where

dwells. While the concept has a

geological Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth s ...

origin, it is an indication of the effect of both

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

and Matthew F. Maury on the

Earth sciences Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical, chemical, and biological complex constitutions and synergistic linkages of Earth's four spheres ...

. The biosphere's ecological context comes from the 1920s (see

Vladimir I. Vernadsky Vladimir Ivanovich Vernadsky (), also spelt Volodymyr Ivanovych Vernadsky (; – 6 January 1945), was a Russian, Ukrainian, and Soviet mineralogist and geochemist who is considered one of the founders of geochemistry, biogeochemistry, and rad ...

), preceding the 1935 introduction of the term "

" by Sir

Arthur Tansley Sir Arthur George Tansley FLS, FRS (15 August 1871 – 25 November 1955) was an English botanist and a pioneer in the science of ecology. Educated at Highgate School, University College London and Trinity College, Cambridge, Tansley taught ...

(see ecology history). Vernadsky defined

ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...

as the science of the biosphere. It is an

interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of multiple academic disciplines into one activity (e.g., a research project). It draws knowledge from several fields such as sociology, anthropology, psychology, economi ...

concept for integrating

astronomy Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest includ ...

geophysics Geophysics () is a subject of natural science concerned with the physical processes and Physical property, properties of Earth and its surrounding space environment, and the use of quantitative methods for their analysis. Geophysicists conduct i ...

meteorology Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agricultur ...

biogeography Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities o ...

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the e ...

hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

and, generally speaking, all life and Earth sciences.

Narrow definition

Geochemists define the biosphere as being the total sum of living organisms (the "

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

" or " biota" as referred to by biologists and ecologists). In this sense, the biosphere is but one of four separate components of the geochemical model, the other three being ''

geosphere There are several conflicting usages of geosphere, variously defined. In Aristotelian physics, the term was applied to four spherical ''natural places'', concentrically nested around the center of the Earth, as described in the lectures '' Ph ...

'', ''

'', and ''

''. When these four component spheres are combined into one system, it is known as the ecosphere. This term was coined during the 1960s and encompasses both biological and physical components of the planet. The Second International Conference on Closed Life Systems defined ''biospherics'' as the science and technology of analogs and

models A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin , . Models can be divided int ...

of Earth's biosphere; i.e., artificial Earth-like biospheres. Others may include the creation of artificial non-Earth biospheres—for example, human-centered biospheres or a native

Martian Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. Trends in the planet's portrayal have largely been influenced by advances in planetary science. It became the most popular celes ...

biosphere—as part of the topic of biospherics.

Earth's biosphere

Overview

Currently, the total number of

living cells The cell is the basic structural and functional unit of all life, forms of life. Every cell consists of cytoplasm enclosed within a Cell membrane, membrane; many cells contain organelles, each with a specific function. The term comes from the ...

on the Earth is estimated to be 10³⁰; the total number since the beginning of Earth, as 10⁴⁰, and the total number for the entire time of a habitable planet Earth as 10⁴¹. This is much larger than the total number of estimated stars (and Earth-like planets) in the observable universe as 10²⁴, a number which is more than all the grains of beach sand on planet Earth; but less than the total number of atoms estimated in the observable universe as 10⁸²; and the estimated total number of stars in an inflationary universe (observed and unobserved), as 10¹⁰⁰.

Age

The earliest evidence for life on Earth includes

biogenic A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, it has developed to encompass any constituents, secretions, and metabolites of p ...

graphite Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable ...

found in 3.7 billion-year-old

metasediment In geology, metasedimentary rock is a type of metamorphic rock. Such a rock was first formed through the deposition and solidification of sediment Sediment is a solid material that is transported to a new location where it is deposited. It occu ...

ary rocks from

Western Greenland Kitaa, originally Vestgrønland ("West Greenland"), is a former administrative division of Greenland. It was by far the most populated of the divisions, being home to almost 90% of the total population. The divisions were de facto replaced by s ...

and

microbial mat A microbial mat is a multi-layered sheet or biofilm of microbial colonies, composed of mainly bacteria and/or archaea. Microbial mats grow at interfaces between different types of material, mostly on submerged or moist surfaces, but a few surviv ...

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

found in 3.48 billion-year-old

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

from

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. More recently, in 2015, "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia. Early edition, published online before print. In 2017, putative fossilized

microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...

s (or

microfossils A microfossil is a fossil that is generally between 0.001 mm and 1 mm in size, the visual study of which requires the use of light or electron microscopy. A fossil which can be studied with the naked eye or low-powered magnification, ...

) were announced to have been discovered in

hydrothermal vent Hydrothermal vents are fissures on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hot ...

precipitates in the

Nuvvuagittuq Belt The Nuvvuagittuq Greenstone Belt (NGB; Inuktitut: ) is a sequence of metamorphosed mafic to ultramafic volcanic and associated sedimentary rocks (a greenstone belt) located on the eastern shore of Hudson Bay, 40 km southeast of Inukjuak, Qu ...

of Quebec, Canada that were as old as 4.28 billion years, the oldest record of life on earth, suggesting "an almost instantaneous emergence of life" after ocean formation 4.4 billion years ago, and not long after the

formation of the Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is c ...

4.54 billion years ago. According to biologist

Stephen Blair Hedges file:Stephen Hedges.jpg, Blair Hedges Stephen Blair Hedges (known as S. Blair Hedges) is Laura H. Carnell Professor of Science and director of the Center for Biodiversity at Temple University where he researches the Tree of life (biology), tree o ...

, "If life arose relatively quickly on Earth ... then it could be common in the

universe The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...

Extent

Every part of the planet, from the

polar Polar may refer to: Geography * Geographical pole, either of the two points on Earth where its axis of rotation intersects its surface ** Polar climate, the climate common in polar regions ** Polar regions of Earth, locations within the polar circ ...

ice caps to the

equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

, features life of some kind. Recent advances in

microbiology Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellula ...

have demonstrated that microbes live deep beneath the Earth's terrestrial surface and that the total mass of

microbial A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

life in so-called "uninhabitable zones" may, in

, exceed all animal and plant life on the surface. The actual thickness of the biosphere on Earth is difficult to measure. Birds typically fly at altitudes as high as and fish live as much as underwater in the

Puerto Rico Trench The Puerto Rico Trench is located on the boundary between the North Atlantic Ocean and Caribbean Sea, parallel to and north of Puerto Rico, where the oceanic trench reaches the deepest points in the Atlantic Ocean. The trench is associated with ...

. There are more extreme examples for life on the planet:

Rüppell's vulture Rüppell's vulture (''Gyps rueppelli''), also called Rüppell's griffon vulture, named after Eduard Rüppell, is a large, resident bird of prey, mainly native to the Sahel region and East Africa. It is considered to be the highest-flying bird, ...

has been found at

altitude Altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum (geodesy), datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometr ...

s of ;

bar-headed geese The bar-headed goose (''Anser indicus'') is a goose that breeds in Central Asia in colonies of thousands near mountain lakes and winters in South Asia, as far south as peninsular India. It lays three to eight eggs at a time in a ground nest. It ...

migrate at altitudes of at least ;

yak The yak (''Bos grunniens''), also known as the Tartary ox, grunting ox, hairy cattle, or domestic yak, is a species of long-haired domesticated cattle found throughout the Himalayan region, the Tibetan Plateau, Tajikistan, the Pamir Mountains ...

s live at elevations as high as above sea level;

mountain goat The mountain goat (''Oreamnos americanus''), also known as the Rocky Mountain goat, is a cloven-footed mammal that is endemic to the remote and rugged mountainous areas of western North America. A subalpine to truly alpine species, it is a s ...

s live up to . Herbivorous animals at these elevations depend on lichens, grasses, and herbs. Life forms live in every part of the Earth's biosphere, including

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

hot spring A hot spring, hydrothermal spring, or geothermal spring is a Spring (hydrology), spring produced by the emergence of Geothermal activity, geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow ...

s, inside rocks at least deep underground, and at least high in the atmosphere. Marine life under many forms has been found in the deepest reaches of the

world ocean The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian, Antarctic/Southern, and ...

while much of the

deep sea The deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combination of low tempe ...

remains to be explored. Under certain test conditions, microorganisms have been observed to survive the vacuum of outer space. The total amount of soil and subsurface bacterial

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

is estimated as 5 × 10¹⁷ g. The mass of

prokaryote A prokaryote (; less commonly spelled procaryote) is a unicellular organism, single-celled organism whose cell (biology), cell lacks a cell nucleus, nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Ancient Gree ...

microorganisms—which includes bacteria and archaea, but not the nucleated eukaryote microorganisms—may be as much as 0.8 trillion tons of carbon (of the total biosphere

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

, estimated at between 1 and 4 trillion tons). Barophilic marine microbes have been found at more than a depth of in the

Mariana Trench The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about east of the Mariana Islands; it is the deep sea, deepest oceanic trench on Earth. It is crescent-shaped and measures about in length and in width. The maxi ...

, the deepest spot in the Earth's oceans. In fact, single-celled life forms have been found in the deepest part of the Mariana Trench, by the

Challenger Deep The Challenger Deep is the List of submarine topographical features#List of oceanic trenches, deepest known point of the seabed of Earth, located in the western Pacific Ocean at the southern end of the Mariana Trench, in the ocean territory o ...

, at depths of . Other researchers reported related studies that microorganisms thrive inside rocks up to below the sea floor under of ocean off the coast of the

northwestern United States The Northwestern United States, also known as the American Northwest or simply the Northwest, is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, Idaho, Montana and Wyoming ...

, as well as beneath the seabed off Japan. Culturable thermophilic microbes have been extracted from cores drilled more than into the

Earth's crust Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

, from rocks between . Temperature increases with increasing depth into the Earth's crust. The rate at which the temperature increases depends on many factors, including the type of crust (continental vs. oceanic), rock type, geographic location, etc. The greatest known temperature at which microbial life can exist is (''

Methanopyrus kandleri ''Methanopyrus'' is a genus of methanogen, with a single described species, ''Methanopyrus kandleri''. It is a rod-shaped hyperthermophile, discovered on the wall of a black smoker from the Gulf of California at a depth of 2,000 m, at temper ...

'' Strain 116). It is likely that the limit of life in the "

deep biosphere The deep biosphere is the part of the biosphere that resides below the first few meters of the ocean's surface. It extends below the continental surface and below the sea surface, at temperatures that may reach beyond which is comparable to s ...

" is defined by temperature rather than absolute depth. On 20 August 2014, scientists confirmed the existence of microorganisms living below the ice of

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

. Earth's biosphere is divided into several

biome A biome () is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. In 1935, Tansley added the ...

s, inhabited by fairly similar

flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...

and

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

. On land, biomes are separated primarily by

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

. Terrestrial biomes lying within the

Arctic The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...

and

Antarctic Circle The Antarctic Circle is the most southerly of the five major circles of latitude that mark maps of Earth. The region south of this circle is known as the Antarctic, and the zone immediately to the north is called the Southern Temperate Zone. So ...

s are relatively barren of

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

and

animal Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, ...

life. In contrast, most of the more populous biomes lie near the

Annual variation

Artificial biospheres

Experimental biospheres, also called

closed ecological system Closed ecological systems or contained ecological systems (CES) are ecosystems that do not rely on matter exchange with any part outside the system. The term is most often used to describe small, man-made ecosystems. Such systems can potentially ...

s, have been created to study ecosystems and the potential for supporting life outside the Earth. These include spacecraft and the following terrestrial laboratories: *

Biosphere 2 University of Arizona Biosphere 2 is an American Earth system science research facility located in Oracle, Arizona. Its mission is to serve as a center for research, outreach, teaching, and lifelong learning about Earth, its living systems, and i ...

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, United States, 3.15 acres (13,000 m²). * BIOS-1, BIOS-2 and

BIOS-3 BIOS-3 is an experimental closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Russia. Its construction began in 1965, and was completed in 1972. BIOS-3 consists of a underground steel structure suitable for up to three persons, an ...

at the Institute of Biophysics in

Krasnoyarsk Krasnoyarsk is the largest types of inhabited localities in Russia, city and administrative center of Krasnoyarsk Krai, Russia. It is situated along the Yenisey, Yenisey River, and is the second-largest city in Siberia after Novosibirsk, with a p ...

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

, in what was then the

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

. * Biosphere J (CEEF, Closed Ecology Experiment Facilities), an experiment in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. * Micro-Ecological Life Support System Alternative (

MELiSSA Melissa is a feminine given name. The name comes from the Greek language, Greek word μέλισσα (''mélissa''), "bee", which in turn comes from μέλι (''meli''), "honey". In Hittite language, Hittite, ''melit'' signifies "honey". Meliss ...

) at

Autonomous University of Barcelona The Autonomous University of Barcelona (; Spanish: ; ; UAB) is a public university mostly located in Cerdanyola del Vallès, near the city of Barcelona in Catalonia, Spain. , the university consists of 57 departments in the experimental, lif ...

Extraterrestrial biospheres

No biospheres have been detected beyond the Earth; therefore, the existence of extraterrestrial biospheres remains hypothetical. The

rare Earth hypothesis In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the origin of life and the evolution of biological complexity, such as sexually reproducing, multicellular organisms on Earth, and subsequently human intelligence, ...

suggests they should be very rare, save ones composed of

life only. On the other hand,

Earth analog An Earth analog, also called an Earth twin or second Earth, is a Exoplanet, planet or Exomoon, moon with environmental conditions similar to those found on Earth. The term Earth-like planet is also used, but this term may refer to any terrestria ...

s may be quite numerous, at least in the

Milky Way galaxy The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are ...

, given the large number of planets. Three of the planets discovered orbiting

TRAPPIST-1 , - ! style="background-color: #FFFFC0; text-align: center;" colspan="2", Characteristics , - style="vertical-align:top" ! style="text-align:left" , Evolutionary stage , Main sequence , - style="vertical-align:top" ! style="text-ali ...

could possibly contain biospheres. Given limited understanding of

abiogenesis Abiogenesis is the natural process by which life arises from non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single even ...

, it is currently unknown what percentage of these planets actually develop biospheres. Based on observations by the

Kepler Space Telescope The Kepler space telescope is a defunct space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orb ...

team, it has been calculated that provided the probability of abiogenesis is higher than 1 to 1000, the closest alien biosphere should be within 100 light-years from the Earth. It is also possible that artificial biospheres will be created in the future, for example with the

terraforming of Mars The terraforming of Mars or the terraformation of Mars is a hypothetical procedure that would consist of a planetary engineering project or concurrent projects aspiring to transform Mars from a planet hostile to life to one that could sustai ...

References

External links

Article on the Biosphere at Encyclopedia of Earth

GLOBIO.info
an ongoing programme to map the past, current and future impacts of human activities on the biosphere
Paul Crutzen Interview
freeview video of

Paul Crutzen Paul Jozef Crutzen (; 3 December 1933 – 28 January 2021) was a Dutch meteorologist and atmospheric chemistry, atmospheric chemist. In 1995, he was awarded the Nobel Prize in Chemistry alongside Mario Molina and F. Sherwood Rowland, Frank Sherw ...

Nobel Laureate for his work on decomposition of ozone talking to Harry Kroto Nobel Laureate by the Vega Science Trust.
Atlas of the Biosphere
{{Authority control Oceanography Superorganisms Biological systems