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Astrobiology

Astrobiology
Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe: extraterrestrial life and life on Earth. This interdisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry, laboratory and field research into the origins and early evolution of life on Earth, and studies of the potential for life to adapt to challenges on Earth and in outer space.[2] Astrobiology addresses the question of whether life exists beyond Earth, and how humans can detect it if it does.[3] (The term exobiology is similar but more specific — it covers the search for life beyond Earth, and the effects of extraterrestrial environments on living things.)[4] Overview[edit] It is not known whether life elsewhere in the universe would utilize cell structures like those found on Earth. (Chloroplasts within plant cells shown here.)[19] Methodology[edit] Related:  wikipedia.org and pagesalien life

Ancient astronauts Ancient astronauts or ancient aliens[1] is a pseudo-scientific hypothesis that posits intelligent extraterrestrial beings have visited Earth and made contact with humans in antiquity and prehistory.[2] Proponents suggest that this contact influenced the development of human cultures, technologies, and religions. A common claim is that deities from most, if not all, religions are actually extraterrestrial in nature, and that such visitors' advanced technologies were wrongly understood by primitive men as evidence of divine status.[3][4] Proposers subscribing to the resultant paleocontact hypothesis proposal have popularized, particularly in the latter half of the 20th century, include Erich von Däniken, Giorgio A. Tsoukalos, Zecharia Sitchin, Robert K. Overview[edit] Proponents of the ancient astronaut hypotheses often maintain that humans are either descendants or creations of extraterrestrial beings who landed on Earth thousands of years ago. Artist rendering of the FOXP2 protein

Astronautics Astronautics (alternatively cosmonautics), is the theory and practice of navigation beyond the Earth's atmosphere. In other words, it is the science and technology of spaceflight. The term astronautics was coined by analogy with aeronautics. As there is a certain degree of technology overlapping between the two fields, the term aerospace is often used to describe them both. History[edit] The early history of astronautics is theoretical: the fundamental mathematics of space travel was established by Isaac Newton in his 1687 treatise Philosophiae Naturalis Principia Mathematica.[2] Other mathematicians, such as Swiss Leonhard Euler and Italian Joseph Louis Lagrange also made essential contributions in the 18th and 19th centuries. ), combined mass of propellant and spacecraft ( ) and exhaust velocity of the propellant ( In fact this equation was derived earlier by William Moore, a British mathematician who worked at the Royal Military Academy at Woolwich. Subdisciplines[edit] See also[edit]

Drake equation The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy. The equation was written in 1961 by Frank Drake not for purposes of quantifying the number of civilizations,[1] but intended as a way to stimulate scientific dialogue at the world's first SETI meeting, in Green Bank, West Virginia. The equation summarizes the main concepts which scientists must contemplate when considering the question of other radio-communicative life.[1] The Drake equation has proved controversial since several of its factors are currently unknown, and estimates of their values span a very wide range. History[edit] In September 1959, physicists Giuseppe Cocconi and Philip Morrison published an article in the journal Nature with the provocative title "Searching for Interstellar Communications Soon thereafter, Drake hosted a "search for extraterrestrial intelligence" meeting on detecting their radio signals. where: and

Paranormal This article is about unexplained phenomena. For phenomena not subject to laws of nature, see supernatural. For unexplained but presumed natural phenomena, see preternatural. Paranormal events are events that can not readily be explained by "the range of normal experience or scientific explanation A paranormal phenomenon is different from hypothetical concepts such as dark matter and dark energy. Scientific evidence does not support the existence of paranormal phenomena.[6] Etymology[edit] Paranormal subjects[edit] On the classification of paranormal subjects, Terence Hines in his book Pseudoscience and the Paranormal (2003) wrote: The paranormal can best be thought of as a subset of pseudoscience. The most notable paranormal beliefs include those that pertain to ghosts, extraterrestrial life, unidentified flying objects and cryptids.[11] One could argue though, that subjects such as the Drake equation, do operate on logical grounds while still being "paranormal" in nature. Cryptids[edit]

Extraterrestrial Life The official U.S. government position on extraterrestrial life and the three major efforts to search for it. Clockwise from top left: The development and testing of hypotheses on extraterrestrial life is known as "exobiology" or "astrobiology", although astrobiology also considers Earth-based life in its astronomical context. On 13 February 2015, scientists (including Geoffrey Marcy, Seth Shostak, Frank Drake, Elon Musk and David Brin) at a convention of the American Association for the Advancement of Science, discussed Active SETI and whether transmitting a message to possible intelligent extraterrestrials in the Cosmos was a good idea;[5][6] one result was a statement, signed by many, that a "worldwide scientific, political and humanitarian discussion must occur before any message is sent".[7] §Background §Possible basis §Biochemistry All life on Earth is based upon 26 chemical elements. Life on Earth requires water as its solvent in which biochemical reactions take place.

Astrochemistry Astrochemistry is the study of the abundance and reactions of chemical elements and molecules in the universe, and their interaction with radiation.[citation needed] The discipline is an overlap of astronomy and chemistry. The word "astrochemistry" may be applied to both the Solar System and the interstellar medium. The study of the abundance of elements and isotope ratios in Solar System objects, such as meteorites, is also called cosmochemistry, while the study of interstellar atoms and molecules and their interaction with radiation is sometimes called molecular astrophysics. The formation, atomic and chemical composition, evolution and fate of molecular gas clouds is of special interest, because it is from these clouds that solar systems form. Spectroscopy[edit] One particularly important experimental tool in astrochemistry is spectroscopy, the use of telescopes to measure the absorption and emission of light from molecules and atoms in various environments. Research[edit]

Noogenesis Noogenesis (Ancient Greek: νοῦς=mind + γένεσις=becoming) is the emergence of intelligent forms of life. The term was first used by Pierre Teilhard de Chardin in regard to the evolution of humans. It also used in astrobiology in regard to the emergence of forms of life capable of technology and so interstellar communication and travel. Teilhard[edit] Noogenesis began with reflective thought; or with the first human beings. Teilhard believes that because human beings are self-reflective (i.e. self-conscious) they constitute a new sphere of existence on earth: the sphere of thought, or the noosphere. Teilhard imagines that noogenesis will eventually reach a critical point of consciousness, brought about by a maximum tension of human socialization. Astrobiology[edit] References[edit]

Life Life is a characteristic distinguishing physical entities having signaling and self-sustaining processes from those that do not,[1][2] either because such functions have ceased (death), or because they lack such functions and are classified as inanimate.[3][4][5] Biology is a science concerned with the study of life. Though life is confirmed only on the Earth, many think that extraterrestrial life is not only plausible, but probable or inevitable.[15][16] Other planets and moons in the Solar System have been examined for evidence of having once supported simple life, and projects such as SETI have attempted to detect radio transmissions from possible alien civilizations. According to the panspermia hypothesis, microscopic life exists throughout the Universe, and is distributed by meteoroids, asteroids and planetoids.[17] Early theories Materialism Herds of zebra and impala gathering on the Maasai Mara plain Hylomorphism Vitalism Vitalism is the belief that the life-principle is non-material.

Astrobiology: The Living Universe - Main Page Astrobiology: The Living Universe is the web's premiere educational resource for astrobiology, featuring in-depth information and interviews on exobiology, planetary biology, the origins of life and human spaceflight. Our site doesn't end with that however - every single page within this website is also available in an enhanced PDF printable format and we have a network of forums and interactive applets as well as a number of Flash animations. Find out more about the Living Universe >> 30/1/01: We're finally back, and we're working flat-out to update every single page within this website, and not just that but also to ensure that no page is more than one month out of date. 16 of the updated articles are now online, and soon you'll be able to know that you're reading the most comprehensive and up-to-date source of information on Astrobiology on the entire Internet.

Cosmochemistry Meteorites are often studied as part of cosmochemistry. Cosmochemistry or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions.[1] This is done primarily through the study of the chemical composition of meteorites and other physical samples. Given that the asteroid parent bodies of meteorites were some of the first solid material to condense from the early solar nebula, cosmochemists are generally, but not exclusively, concerned with the objects contained within the solar system. History[edit] During the 1950s and 1960s, cosmochemistry became more accepted as a science. In October 2011, scientists reported that cosmic dust contains complex organic matter ("amorphous organic solids with a mixed aromatic-aliphatic structure") that could be created naturally, and rapidly, by stars.[5][6][7] Meteorites[edit] See also[edit] References[edit] External links[edit]

Abiogenesis Scientific hypotheses about the origins of life can be divided into a number of categories. Many approaches investigate how self-replicating molecules or their components came into existence. On the assumption that life originated spontaneously on Earth, the Miller–Urey experiment and similar experiments demonstrated that most amino acids, often called "the building blocks of life", can be racemically synthesized in conditions which were intended to be similar to those of the early Earth. Several mechanisms have been investigated, including lightning and radiation. Other approaches ("metabolism first" hypotheses) focus on understanding how catalysis in chemical systems in the early Earth might have provided the precursor molecules necessary for self-replication. Early conditions[edit] The Hadean Earth is thought to have had a secondary atmosphere, formed through degassing of the rocks that accumulated from planetesimal impactors. The earliest life on Earth[edit] Current models[edit]

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