Astrobiology, formerly known as exobiology, is an interdisciplinary scientific field concerned with the origins, early evolution, distribution, and future of life in the universe.
Astrobiology considers the question of whether extra-terrestrial life exists, and if it does, how humans can detect it.
Astrobiology makes use of molecular biology, biophysics, biochemistry, chemistry, astronomy, physical cosmology, exoplanet science and geology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth.
The term was first proposed by the Russian (Soviet) astronomer Gavriil Tikhov in 1953. Astrobiology is derived from the Greek astron, "constellation, star"; bios, "life"; and logia, study.
While it is an emerging and developing field, the question of whether life exists elsewhere in the universe is a verifiable hypothesis and thus a valid line of scientific inquiry.
Though once considered outside the mainstream of scientific inquiry, astrobiology has become a formalized field of study.
Biochemistry may have begun shortly after the Big Bang, 13.8 billion years ago, during a habitable epoch when the Universe was only 10–17 million years old.
According to the panspermia hypothesis, microscopic life distributed by meteoroids, asteroids and other small Solar System bodie may exist throughout the universe.
According to research published in August 2015, very large galaxies may be more favourable to the creation and development of habitable planets than such smaller galaxies as the Milky Way.
Nonetheless, Earth is the only place in the universe humans know to harbour life.
Estimates of habitable zones around other stars, sometimes referred to as "Goldilocks zones," along with the discovery of hundreds of extrasolar planets and new insights into extreme habitats here on Earth, suggest that there may be many more habitable places in the universe than considered possible until very recently.
Link to YouTube video www.youtube.com/watch?v=eJTfcV1ZceE
NASA's interest in exobiology first began with the development of the U.S. Space Program.
In 1959, NASA funded its first exobiology project, and in 1960, NASA founded an Exobiology Program, which is now one of four main elements of NASA's current Astrobiology Program.
In 1971, NASA funded the search for extra-terrestrial intelligence (SETI) to search radio frequencies of the electromagnetic spectrum for interstellar communications transmitted by extra-terrestrial life outside the Solar System.
NASA's Viking missions to Mars, launched in 1976, included three biology experiments designed to look for metabolism of present life on Mars.
Beagle 2 was an unsuccessful British Mars lander that formed part of the European Space Agency's 2003 Mars Express mission.
Its primary purpose was to search for signs of life on Mars, past or present. Although it landed safely, it was unable to correctly deploy its solar panels and telecom antenna.
EXPOSE is a multi-user facility mounted in 2008 outside the International Space Station dedicated to astrobiology.
EXPOSE was developed by the European Space Agency (ESA) for long-term spaceflights that allow exposure of organic chemicals and biological samples to outer space in low Earth orbit.
The Mars Science Laboratory (MSL) mission landed the Curiosity rover that is currently in operation on Mars It was launched 26 November 2011, and landed at Gale Crater on 6 August 2012.
Mission objectives are to help assess Mars' habitability and in doing so, determine whether Mars is or has ever been able to support life, collect data for a future human mission, study Martian geology, its climate.
The European Space Agency's astrobiology roadmap from 2016, identified five main research topics, and specifies several key scientific objectives for each topic. The five research topics are:
1) Origin and evolution of planetary systems;
2) Origins of organic compounds in space;
3) Rock-water-carbon interactions, organic synthesis on Earth, and steps to life;
4) Life and habitability;
5) Biosignatures as facilitating life detection.
The Tanpopo mission is an orbital astrobiology experiment investigating the potential interplanetary transfer of life, organic compounds, and possible terrestrial particles in the low Earth orbit.
The collection and exposure phase took place from May 2015 through February 2018 utilizing the Exposed Facility located on the exterior of Kibo, the Japanese Experimental Module of the International Space Station.
The purpose is to assess the panspermia hypothesis and the possibility of natural interplanetary transport of microbial life as well as prebiotic organic compounds.
Early mission results show evidence that some clumps of microorganism can survive for at least one year in space.
This may support the idea that clumps greater than 0.5 millimetres of microorganisms could be one way for life to spread from planet to planet.
ExoMars rover (Rosalind Franklin) is a robotic mission to Mars to search for possible biosignatures of Martian life, past or present.
This astrobiological mission is currently under development by the European Space Agency (ESA) in partnership with the Russian Federal Space Agency (Roscosmos); it is planned for a 2020 launch. Currently having problems with parachutes.
Mars 2020 rover mission is under development by NASA for a launch in 2020.
It will investigate environments on Mars relevant to astrobiology, investigate its surface geological processes and history, including the assessment of its past habitability and potential for preservation of biosignatures and biomolecules within accessible geological materials.
The Science Definition Team is proposing the rover collect and package at least 31 samples of rock cores and soil for a later mission to bring back for more definitive analysis in laboratories on Earth.
Europa Clipper is a mission planned by NASA for a 2025 launch that will conduct detailed reconnaissance of Jupiter's moon Europa and will investigate whether its internal ocean could harbour conditions suitable for life.
It will also aid in the selection of future landing sites.
Link To YouTube Video www.youtube.com/watch?v=K-N0_kMvtFU