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**Definition and Origin of Biosphere**:
– Coined by geologist Eduard Suess in 1875.
– Vernadsky defined ecology as the science of the biosphere.
– Term ‘ecosystem’ introduced by Sir Arthur Tansley in 1935.
– Biosphere integrates various Earth sciences.
– Narrow definition as the total sum of living organisms.
– Ecosphere encompasses biological and physical components.
– Biospherics is the science of analogs and models.
– Includes creation of artificial non-Earth biospheres.

**Earth’s Biosphere Overview**:
– Estimated total number of living cells on Earth is 10^30.
– Total mass of microbial life underground may exceed surface life.
– Thickness of Earth’s biosphere is challenging to measure.
– Life exists in extreme environments on Earth.

**Age and Extent of Life in Earth’s Biosphere**:
– Evidence of life on Earth dates back to 3.7 billion years.
– Fossilized microorganisms discovered in rocks as old as 4.28 billion years.
– Microbes live deep below Earth’s surface.
– Birds fly at altitudes up to 1,800m; fish live 8,372m underwater.
– Prokaryote microorganisms may total 0.8 trillion tons of carbon.

**Biosphere Variations and Artificial Biospheres**:
– Annual variations in land vegetation and ocean phytoplankton.
– Artificial biospheres like Biosphere 2 in Arizona.
– Closed ecological systems study ecosystems.
– Terrestrial laboratories include BIOS-1, BIOS-2, and BIOS-3.

**Extraterrestrial Biospheres and Further Exploration**:
– No extraterrestrial biospheres detected.
– Rare Earth hypothesis suggests rare extraterrestrial biospheres.
– Earth analogs may be numerous in the Milky Way galaxy.
– Three planets orbiting TRAPPIST-1 may contain biospheres.
– Probability of abiogenesis determines development of biospheres.
– Abundance of extraterrestrial life after the Kepler mission.

Biosphere (Wikipedia)

The biosphere (from Greek βίος bíos "life" and σφαῖρα sphaira "sphere"), also known as the ecosphere (from Greek οἶκος oîkos "environment" and σφαῖρα), is the worldwide sum of all ecosystems. It can also be termed the zone of life on Earth. The biosphere (which is technically a spherical shell) is virtually a closed system with regard to matter, with minimal inputs and outputs. Regarding energy, it is an open system, with photosynthesis capturing solar energy at a rate of around 100 terawatts. By the most general biophysiological definition, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, cryosphere, hydrosphere, and atmosphere. The biosphere is postulated to have evolved, beginning with a process of biopoiesis (life created naturally from non-living matter, such as simple organic compounds) or biogenesis (life created from living matter), at least some 3.5 billion years ago.

A false color composite of global oceanic and terrestrial photoautotroph abundance, from September 2001 to August 2017. Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center and ORBIMAGE.[citation needed]

In a general sense, biospheres are any closed, self-regulating systems containing ecosystems. This includes artificial biospheres such as Biosphere 2 and BIOS-3, and potentially ones on other planets or moons.

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