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Tholin
Tholins (after the Greek (') "hazy" or "muddy"; from the ancient Greek word meaning "sepia ink") are a wide variety of organic compounds formed by solar ultraviolet or cosmic rays, cosmic ray irradiation of simple carbon-containing compounds such as carbon dioxide (), methane () or ethane (), often in combination with nitrogen () or water ().Sarah Hörs"What in the world(s) are tholins?" Planetary Society, July 23, 2015. Retrieved 30 Nov 2016. Tholins are disordered polymer-like materials made of repeating chains of linked subunits and complex combinations of functional groups, typically nitriles and hydrocarbons, and their degraded forms such as amines and Phenyl group, phenyls. Tholins do not form naturally on modern-day Earth, but they are found in great abundance on the surfaces of icy bodies in the outer Solar System, and as reddish aerosols in the atmospheres of outer Solar System planets and moons. In the presence of water, tholins could be raw materials for prebiotic ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Miller–Urey Experiment
The Miller–Urey experiment, or Miller experiment, was an experiment in chemical synthesis carried out in 1952 that simulated the conditions thought at the time to be present in the Prebiotic atmosphere, atmosphere of the early, prebiotic Earth. It is seen as one of the first successful experiments demonstrating the synthesis of organic compounds from inorganic compound, inorganic constituents in an Abiogenesis, origin of life scenario. The experiment used methane (CH4), ammonia (NH3), hydrogen (H2), in ratio 2:1:2, and water (H2O). Applying an electric arc (simulating lightning) resulted in the production of amino acids. It is regarded as a groundbreaking experiment, and the classic experiment investigating the origin of life (abiogenesis). It was performed in 1952 by Stanley Miller, supervised by Nobel laureate Harold Urey at the University of Chicago, and published the following year. At the time, it supported Alexander Oparin's and J. B. S. Haldane's hypothesis that the cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Titan (moon)
Titan is the largest moon of Saturn and the List of Solar System objects by size, second-largest in the Solar System. It is the only Natural satellite, moon known to have an atmosphere denser than the Atmosphere of Earth, Earth's and is the only known object in space—other than Earth—on which there is clear evidence that stable bodies of liquid exist. Titan is one of seven List of gravitationally rounded objects of the Solar System, gravitationally rounded moons of Saturn and the second-most distant among them. Frequently described as a Planetary-mass moon, planet-like moon, Titan is 50% larger in diameter than Earth's Moon and 80% more Mass, massive. It is the second-largest moon in the Solar System after Jupiter's Ganymede (moon), Ganymede and is larger than Mercury (planet), Mercury; yet Titan is only 40% as massive as Mercury, because Mercury is mainly iron and rock while much of Titan is ice, which is less dense. Discovered in 1655 by the Dutch astronomer Christiaan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bishun Khare
Bishun Narain Khare (27 June 1933 – 20 August 2013) was a scientist who specialized in the chemistry of planetary atmospheres and of molecules relevant to biology. He published several papers on tholins, the organic molecules formed by ultraviolet radiation or cosmic rays. From 1968 to 1996, Khare worked in Carl Sagan's Laboratory for Planetary Studies at Cornell University. During this time he appeared in the ''Cosmos'' television series. From 1996 to 1998, he worked at the NASA Ames Research Center and from 1998 onward he worked at the SETI Institute. After his death, the International Astronomical Union named a crater on Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ... after him called the Khare Crater. Publications References/ External linksProfile on SETI [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Mordor Macula Cropped
In J. R. R. Tolkien's fictional world, fictional continent of Middle-earth, Mordor (; from Sindarin ''Black Land'' and Quenya ''Land of Shadow'') is a dark realm. It lay to the east of Gondor and the great river Anduin, and to the south of Mirkwood. #Mount Doom, Mount Doom, a volcano in Mordor, was the goal of the Fellowship of the Ring (characters), Fellowship of the Ring in the quest to destroy the One Ring. Mordor was surrounded by three mountain ranges, to the north, the west, and the south. These both protected the land from invasion and kept those living in Mordor from escaping. Commentators have noted that Mordor was influenced by Tolkien's own experiences in the industrial Black Country of the English Midlands, and by The Great War and Middle-earth, his time fighting in the trenches of the Western Front (World War I), Western Front in the First World War. Tolkien was also familiar with the account of the monster Grendel's unearthly landscapes in the Old English poem ''B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 event, but a process of increasing complexity involving the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. The transition from non-life to life has never been observed experimentally, but many proposals have been made for different stages of the process. The study of abiogenesis aims to determine how pre-life chemical reactions gave rise to life under conditions strikingly different from those on Earth today. It primarily uses tools from biology and chemistry, with more recent approaches attempting a synthesis of many sciences. Life functions through the specialized chemistry of carbon and water, and builds largely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Radiolysis
Radiolysis is the dissociation of molecules by ionizing radiation. It is the cleavage of one or several chemical bonds resulting from exposure to high-energy flux. The radiation in this context is associated with ionizing radiation; radiolysis is therefore distinguished from, for example, photolysis of the Cl2 molecule into two Cl- radicals, where (ultraviolet or visible spectrum) light is used. The chemistry of concentrated solutions under ionizing radiation is extremely complex. Radiolysis can locally modify redox conditions, and therefore the speciation and the solubility of the compounds. Water decomposition Of all the radiation-based chemical reactions that have been studied, the most important is the decomposition of water. When exposed to radiation, water undergoes a breakdown sequence into hydrogen peroxide, hydrogen radicals, and assorted oxygen compounds, such as ozone, which when converted back into oxygen releases great amounts of energy. Some of these are explosive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pyrolysis
Pyrolysis is a process involving the Bond cleavage, separation of covalent bonds in organic matter by thermal decomposition within an Chemically inert, inert environment without oxygen. Etymology The word ''pyrolysis'' is coined from the Greek language, Greek-derived morpheme, elements ''pyro-'' (from Ancient Greek : - "fire, heat, fever") and ''lysis'' ( : - "separation, loosening"). Applications Pyrolysis is most commonly used in the treatment of organic compound, organic materials. It is one of the processes involved in the charring of wood or pyrolysis of biomass. In general, pyrolysis of organic substances produces volatile products and leaves Char (chemistry), char, a carbon-rich solid residue. Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization. Pyrolysis is considered one of the steps in the processes of gasification or combustion. Laypeople often confuse pyrolysis gas with syngas. Pyrolysis gas has a high percentage of heavy tar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Alkyl
In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl group is derived from a cycloalkane by removal of a hydrogen atom from a Ring (chemistry), ring and has the general formula . Typically an alkyl is a part of a larger molecule. In structural formulae, the symbol R is used to designate a generic (unspecified) alkyl group. The smallest alkyl group is methyl, with the formula . Related concepts Alkylation is the addition of alkyl groups to molecules, often by alkylating agents such as Haloalkane, alkyl halides. Alkylating antineoplastic agents are a class of compounds that are used to treat cancer. In such case, the term alkyl is used loosely. For example, nitrogen mustards are well-known alkylating agents, but they are not simple hydrocarbons. In chemistry, alkyl is a group, a substituent, that is attached to ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Formation Of Tholins In Titan's Upper Atmosphere
Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary mineral deposit formed in a cave * Class formation, a topological group acting on a module satisfying certain conditions * Formation (group theory), a class of groups that is closed under some operations * Formation constant, an equilibrium constant for the formation of a complex in solution * Formation enthalpy, standard heat of formation of a compound * Formation (group theory), a class of groups * Formation (geology), a formally named rock stratum or geological unit * Formation of rocks, how rocks are formed * Formation and evolution of the Solar System, history of the Solar System * Rock formation, an isolated, scenic, or spectacular surface rock outcrop * Vegetation formation, a concept used to classify vegetation communities Milita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Heteropolymer
In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are sometimes called ''bipolymers''. Those obtained from three and four monomers are called ''terpolymers'' and ''quaterpolymers'', respectively. Copolymers can be characterized by a variety of techniques such as NMR spectroscopy and size-exclusion chromatography to determine the molecular size, weight, properties, and composition of the material. Commercial copolymers include acrylonitrile butadiene styrene (ABS), styrene/butadiene co-polymer (SBR), nitrile rubber, styrene-acrylonitrile, styrene-isoprene-styrene (SIS) and ethylene-vinyl acetate, all of which are formed by chain-growth polymerization. Another production mechanism is step-growth polymerization, which is used to produce the nylon-12/6/66 copolymer of nylon 12, nylon 6 and n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Carl Sagan
Carl Edward Sagan (; ; November 9, 1934December 20, 1996) was an American astronomer, planetary scientist and science communicator. His best known scientific contribution is his research on the possibility of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by exposure to light. He assembled the first physical messages sent into space, the Pioneer plaque and the Voyager Golden Record, which were universal messages that could potentially be understood by any Extraterrestrial life, extraterrestrial intelligence that might find them. He argued in favor of the hypothesis, which has since been accepted, that the high surface temperatures of Venus are the result of the greenhouse effect.Extract of page 14 Initially an assistant professor at Harvard Universi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Poly(acrylonitrile)
Poly, from the Greek πολύς meaning "many" or "much", may refer to: Businesses * China Poly Group Corporation, a Chinese business group, and its subsidiaries: ** Poly Property, a Hong Kong incorporated Chinese property developer ** Poly Real Estate, a Chinese real estate developer ** Poly Technologies, a defense manufacturing company * Poly (company), formerly Polycom, an American communications technology company People * Poly (footballer) (1906-1986), full name Policarpo Ribeiro de Oliveira, Brazilian footballer * Natasha Poly (born 1985), stage name of Russian supermodel Natalya Sergeyevna Polevshchikova * Poly Styrene (1957–2011), stage name of British musician Marianne Joan Elliott-Said Polytechnic * Hong Kong Polytechnic University, locally known as Poly * Polytechnic Heights, Fort Worth, Texas, neighborhood locally known as Poly * Polytechnic Institute of NYU (now New York University Tandon School of Engineering), locally known as Poly * ''The Rensselaer Polytechn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
