41-430: Astrobiology (also xenology or exobiology ) is a scientific field within the life and environmental sciences that studies the origins , early evolution , distribution, and future of life in the universe by investigating its deterministic conditions and contingent events. As a discipline, astrobiology is founded on the premise that life may exist beyond Earth. Research in astrobiology comprises three main areas:
82-461: A sun -like star, however with developments within extremophile research contemporary astrobiological research often focuses on identifying environments that have the potential to support life based on the availability of an energy source, such as the presence of volcanic activity on a planet or moon that could provide a source of heat and energy. It is important to note that these assumptions are based on our current understanding of life on Earth and
123-410: A role in the emergence of life. List of life sciences This list of life sciences comprises the branches of science that involve the scientific study of life – such as microorganisms , plants, and animals including human beings . This science is one of the two major branches of natural science , the other being physical science , which is concerned with non-living matter. Biology
164-591: Is a common molecule that provides an excellent environment for the formation of complicated carbon-based molecules, and is generally considered necessary for life as we know it to exist. Thus, astrobiological research presumes that extraterrestrial life similarly depends upon access to liquid water, and often focuses on identifying environments that have the potential to support liquid water. Some researchers posit environments of water- ammonia mixtures as possible solvents for hypothetical types of biochemistry . Environmental stability : Where organisms adaptively evolve to
205-507: Is conducted utilising the methodology of planetary and environmental science , especially atmospheric science , for astrobiological applications, and is often conducted through remote sensing and in situ missions. Astrobiology also concerns the study of the origin and early evolution of life on Earth to try to understand the conditions that are necessary for life to form on other planets. This research seeks to understand how life emerged from non-living matter and how it evolved to become
246-519: Is considered to have a narrow scope limited to search of life external to Earth. Another associated term is xenobiology , from the Greek ξένος, "foreign"; βίος , "life"; and -λογία, "study", coined by American science fiction writer Robert Heinlein in his work The Star Beast ; xenobiology is now used in a more specialised sense, referring to 'biology based on foreign chemistry', whether of extraterrestrial or terrestrial (typically synthetic) origin. While
287-576: Is the overall natural science that studies life, with the other life sciences as its sub-disciplines. Some life sciences focus on a specific type of organism. For example, zoology is the study of animals, while botany is the study of plants. Other life sciences focus on aspects common to all or many life forms, such as anatomy and genetics . Some focus on the micro-scale (e.g. molecular biology , biochemistry ) other on larger scales (e.g. cytology , immunology , ethology , pharmacy, ecology). Another major branch of life sciences involves understanding
328-520: The Arecibo message , and computational approaches to detecting and deciphering 'natural' language communication. While some high-profile scientists, such as Carl Sagan , have advocated the transmission of messages, theoretical physicist Stephen Hawking warned against it, suggesting that aliens may raid Earth for its resources. Emerging astrobiological research concerning the study of the origin and early evolution of life on Earth utilises methodologies within
369-443: The extremophiles populating austere environments on Earth, like volcanic and deep sea environments. Research within this topic is conducted utilising the methodology of the geosciences, especially geobiology , for astrobiological applications. The search for biosignatures involves the identification of signs of past or present life in the form of organic compounds , isotopic ratios, or microbial fossils. Research within this topic
410-494: The mind – neuroscience . Life sciences discoveries are helpful in improving the quality and standard of life and have applications in health, agriculture, medicine, and the pharmaceutical and food science industries. For example, it has provided information on certain diseases which has overall aided in the understanding of human health. Robert Heinlein Too Many Requests If you report this error to
451-529: The 1950s and 1960s with the advent of space exploration , when scientists began to seriously consider the possibility of life on other planets. In 1957, the Soviet Union launched Sputnik 1 , the first artificial satellite, which marked the beginning of the Space Age . This event led to an increase in the study of the potential for life on other planets, as scientists began to consider the possibilities opened up by
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#1732869100111492-494: The ESA's Beagle 2 , which failed minutes after landing on Mars, NASA's Phoenix lander , which probed the environment for past and present planetary habitability of microbial life on Mars and researched the history of water, and NASA's Curiosity rover , currently probing the environment for past and present planetary habitability of microbial life on Mars. Astrobiological research makes a number of simplifying assumptions when studying
533-537: The Solar System. In the 1960s-1970s, NASA established the Viking program , which was the first US mission to land on Mars and search for metabolic signs of present life; the results were inconclusive. In the 1980s and 1990s, the field began to expand and diversify as new discoveries and technologies emerged. The discovery of microbial life in extreme environments on Earth, such as deep-sea hydrothermal vents, helped to clarify
574-409: The atmospheres of planets : Scientists are studying the potential for life to exist in the atmospheres of planets, with a focus on the study of the physical and chemical conditions necessary for such life to exist, namely the detection of organic molecules and biosignature gases; for example, the study of the possibility of life in the atmospheres of exoplanets that orbit red dwarfs and the study of
615-408: The biosphere : Scientists are studying the ways in which human activities, such as deforestation, pollution, and the introduction of invasive species, are affecting the biosphere and the long-term survival of life on Earth. Long-term preservation of life : Researchers are exploring ways to preserve samples of life on Earth for long periods of time, such as cryopreservation and genomic preservation, in
656-409: The building blocks of life- amino acids, nucleotides, and lipids- and how these molecules could have formed spontaneously under early Earth conditions. The study of impact events : Scientists are investigating the potential role of impact events- especially meteorites- in the delivery of water and organic molecules to early Earth. The study of the primordial soup : Researchers are investigating
697-399: The conditions and ingredients that were present on the early Earth that could have led to the formation of the first living organisms, such as the presence of water and organic molecules, and how these ingredients could have led to the formation of the first living organisms. This includes the role of water in the formation of the first cells and in catalysing chemical reactions. The study of
738-650: The conditions of the environments in which they reside, environmental stability is considered necessary for life to exist. This presupposes the necessity of a stable temperature , pressure, and radiation levels; resultantly, astrobiological research focuses on planets orbiting Sun -like red dwarf stars . This is because very large stars have relatively short lifetimes, meaning that life might not have time to emerge on planets orbiting them; very small stars provide so little heat and warmth that only planets in very close orbits around them would not be frozen solid, and in such close orbits these planets would be tidally locked to
779-500: The conditions under which it can exist. As our understanding of life and the potential for it to exist in different environments evolves, these assumptions may change. Astrobiological research concerning the study of habitable environments in our solar system and beyond utilises methods within the geosciences. Research within this branch primarily concerns the geobiology of organisms that can survive in extreme environments on Earth, such as in volcanic or deep sea environments, to understand
820-586: The detection of biosignatures, such as the use of remote sensing to search for biosignatures in the atmosphere of exoplanets. SETI and CETI : Scientists search for signals from intelligent extraterrestrial civilizations using radio and optical telescopes within the discipline of extraterrestrial intelligence communications (CETI). CETI focuses on composing and deciphering messages that could theoretically be understood by another technological civilization. Communication attempts by humans have included broadcasting mathematical languages, pictorial systems such as
861-443: The diverse array of organisms we see today. Research within this topic is conducted utilising the methodology of paleosciences, especially paleobiology , for astrobiological applications. Astrobiology is a rapidly developing field with a strong interdisciplinary aspect that holds many challenges and opportunities for scientists. Astrobiology programs and research centres are present in many universities and research institutions around
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#1732869100111902-448: The diversity and activity of microorganisms in environments such as deep mines, subsurface soil, cold glaciers and polar ice, and high-altitude environments. Research also regards the long-term survival of life on Earth, and the possibilities and hazards of life on other planets, including: Biodiversity and ecosystem resilience : Scientists are studying how the diversity of life and the interactions between different species contribute to
943-454: The early magnetic field in protecting the Earth from harmful radiation and helping to stabilise the climate. This research has immense astrobiological implications where the subjects of current astrobiological research like Mars lack such a field. The study of prebiotic chemistry : Scientists are studying the chemical reactions that could have occurred on the early Earth that led to the formation of
984-420: The emergence of life. The study of the early oceans : Scientists are investigating the composition and chemistry of the early oceans and how it may have played a role in the emergence of life, such as the presence of dissolved minerals that could have helped to catalyse the formation of organic molecules. The study of hydrothermal vents : Scientists are investigating the potential role of hydrothermal vents in
1025-411: The event of a catastrophic event that could wipe out most of life on Earth. Emerging astrobiological research concerning the search for planetary biosignatures of past or present extraterrestrial life utilise methodologies within planetary sciences. These include: The study of microbial life in the subsurface of Mars : Scientists are using data from Mars rover missions to study the composition of
1066-436: The feasibility of potential life existing in harsh conditions. The development of new techniques for the detection of biosignatures, such as the use of stable isotopes, also played a significant role in the evolution of the field. The contemporary landscape of astrobiology emerged in the early 21st century, focused on utilising Earth and environmental science for applications within comparate space environments. Missions included
1107-673: The limits of life, and the conditions under which life might be able to survive on other planets. This includes, but is not limited to: Deep-sea extremophiles : Researchers are studying organisms that live in the extreme environments of deep-sea hydrothermal vents and cold seeps. These organisms survive in the absence of sunlight, and some are able to survive in high temperatures and pressures, and use chemical energy instead of sunlight to produce food. Desert extremophiles : Researchers are studying organisms that can survive in extreme dry, high temperature conditions, such as in deserts. Microbes in extreme environments : Researchers are investigating
1148-472: The necessary components for planetary habitability. Carbon and Organic Compounds : Carbon is the fourth most abundant element in the universe and the energy required to make or break a bond is at just the appropriate level for building molecules which are not only stable, but also reactive. The fact that carbon atoms bond readily to other carbon atoms allows for the building of extremely long and complex molecules. As such, astrobiological research presumes that
1189-505: The new technology of space exploration. In 1959, NASA funded its first exobiology project, and in 1960, NASA founded the Exobiology Program, now one of four main elements of NASA's current Astrobiology Program. In 1971, NASA funded Project Cyclops , part of the search for extraterrestrial intelligence , to search radio frequencies of the electromagnetic spectrum for interstellar communications transmitted by extraterrestrial life outside
1230-453: The origin of life, as these environments may have provided the energy and chemical building blocks needed for its emergence. The study of plate tectonics : Scientists are investigating the role of plate tectonics in creating a diverse range of environments on the early Earth. The study of the early biosphere : Researchers are investigating the diversity and activity of microorganisms in the early Earth, and how these organisms may have played
1271-400: The palaeosciences. These include: The study of the early atmosphere : Researchers are investigating the role of the early atmosphere in providing the right conditions for the emergence of life, such as the presence of gases that could have helped to stabilise the climate and the formation of organic molecules. The study of the early magnetic field : Researchers are investigating the role of
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1312-432: The potential for extraterrestrial life, especially intelligent life, has been explored throughout human history within philosophy and narrative, the question is a verifiable hypothesis and thus a valid line of scientific inquiry; planetary scientist David Grinspoon calls it a field of natural philosophy, grounding speculation on the unknown in known scientific theory. The modern field of astrobiology can be traced back to
1353-577: The potential for microbial life in the upper atmosphere of Venus. Telescopes and remote sensing of exoplanets : The discovery of thousands of exoplanets has opened up new opportunities for the search for biosignatures. Scientists are using telescopes such as the James Webb Space Telescope and the Transiting Exoplanet Survey Satellite to search for biosignatures on exoplanets. They are also developing new techniques for
1394-439: The resilience of ecosystems and their ability to recover from disturbances. Climate change and extinction : Researchers are investigating the impacts of climate change on different species and ecosystems, and how they may lead to extinction or adaptation. This includes the evolution of Earth's climate and geology, and their potential impact on the habitability of the planet in the future, especially for humans. Human impact on
1435-427: The role of minerals : Scientists are investigating the role of minerals like clay in catalysing the formation of organic molecules, thus playing a role in the emergence of life on Earth. The study of the role of energy and electricity : Scientists are investigating the potential sources of energy and electricity that could have been available on the early Earth, and their role in the formation of organic molecules, thus
1476-599: The search for extraterrestrial life and the study of the potential for life to exist on other planets. In the 1960s and 1970s, NASA began its astrobiology pursuits within the Viking program , which was the first US mission to land on Mars and search for signs of life . This mission, along with other early space exploration missions, laid the foundation for the development of astrobiology as a discipline. Regarding habitable environments , astrobiology investigates potential locations beyond Earth that could support life, such as Mars , Europa , and exoplanets , through research into
1517-421: The star; whereas the long lifetimes of red dwarfs could allow the development of habitable environments on planets with thick atmospheres. This is significant as red dwarfs are extremely common. ( See also : Habitability of red dwarf systems ). Energy source : It is assumed that any life elsewhere in the universe would also require an energy source. Previously, it was assumed that this would necessarily be from
1558-455: The study of habitable environments in the Solar System and beyond, the search for planetary biosignatures of past or present extraterrestrial life, and the study of the origin and early evolution of life on Earth. The field of astrobiology has its origins in the 20th century with the advent of space exploration and the discovery of exoplanets . Early astrobiology research focused on
1599-509: The subsurface of Mars , searching for biosignatures of past or present microbial life. The study of liquid bodies on icy moons : Discoveries of surface and subsurface bodies of liquid on moons such as Europa , Titan and Enceladus showed possible habitability zones, making them viable targets for the search for extraterrestrial life. As of September 2024, missions like Europa Clipper and Dragonfly are planned to search for biosignatures within these environments. The study of
1640-467: The vast majority of life forms in the Milky Way galaxy are based on carbon chemistries , as are all life forms on Earth. However, theoretical astrobiology entertains the potential for other organic molecular bases for life, thus astrobiological research often focuses on identifying environments that have the potential to support life based on the presence of organic compounds. Liquid water : Liquid water
1681-616: The world, and space agencies like NASA and ESA have dedicated departments and programs for astrobiology research. The term astrobiology was first proposed by the Russian astronomer Gavriil Tikhov in 1953. It is etymologically derived from the Greek ἄστρον , "star"; βίος , "life"; and -λογία , -logia , "study". A close synonym is exobiology from the Greek Έξω, "external"; βίος , "life"; and -λογία , -logia , "study", coined by American molecular biologist Joshua Lederberg ; exobiology