Cosmochemistry is a discipline that studies the chemical composition and evolution law of cosmic matter. It is a branch of astronomy and also a marginal discipline between astronomy and chemistry.The objects of cosmic chemistry research include meteoritesMoon、Planetary systemCelestial objectsInterplanetary matter, Sun, StarInterstellar matter、cosmic ray, galaxies, andIntergalactic matterEtc.
Chinese name
Cosmochemistry
Field
universe
Discipline
Chemistry
Definition
Chemical Composition and Evolution Law of Cosmic Matter
Cosmic chemistry is a branch of science that studies the chemical composition and evolution of cosmic matter.The main research contents include:
Cosmochemistry
① Determine the elements that make up the cosmic matterisotopeAnd molecules, determine their content.
② Discuss the chemical evolution of cosmic matter.This is important for studying the origin of celestial bodies andOrigin of lifeThey are of great significance and also promote the development of cosmochemistry.
The ancients could only speculate, until the 19th century, it gradually became a science.In 1833, Swedish chemist Bezelius first recovered from meteorite debriscomponent analysisIt measured the chemical composition of cosmic matter, andSpectral analysisIt enables people to obtain the chemical composition data of stars.After the 20th century, there were more extensive means. Space observation madeSpectrum analysisExpand to "full wave" range: fromradio, infraredvisible lightreachultraviolet rays、X-ray、Gamma rayCan engage in the study of cosmochemistry, plusSpace explorationDirect landing on the moonMarsIsocelestial collectionrock, soil samples, which has made great progress in this discipline, such asInterstellar moleculeThe discovery of.
Different according to the research object.Cosmic chemistry can be roughly divided into: meteorite chemistryPlanetary systemChemistry, stellar chemistry, interstellar chemistry, isotope cosmochemistrycosmic rayNuclear chemistryEtc.
Cosmochemistry can be divided into several aspects according to the celestial hierarchy and research methods:Meteorite chemistryTo study the chemical composition of various meteorites.Research shows,Carbonaceous chondriteIn the long evolution process of the solar system, the physical and chemical changes are the smallest, which can be regarded as the material of the original solar system“Fossil”；
Planetary chemistry: study planets (including Earth), satellites, asteroidsMeteoroid, comets, andInterplanetary matterChemical composition and chemical evolution;
Stellar chemistryTo study the chemical composition and chemical evolution of stars.The sun is the nearest star, accounting for 99.86% of the total mass of the solar system, so solar chemistry is of great significance to the study of stars and the solar system;
interstellar chemistry : Main observation and verificationInterstellar molecule, study their formation and disintegration;
Isotope cosmochemistry: Measuring theisotopic compositionTo study the origin and evolution of chemical elements, understand the source and formation environment of celestial substances, and explore various high-energy and low-energy processes.determinationradio isotopeIt is the task of isotopic chronology to determine the age of celestial bodies (or cosmic substances) by composition;Cosmic ray nuclear chemistry: Determine the nuclear composition of chemical elements in cosmic rays, speculatecosmic rayIn the process of communicationmediumAnd the chemical composition of cosmic ray sources.[1]
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Cosmic chemistry is the basis of material chemistry and life chemistry.
The formula of western cosmochemistry is dogmatic and fault-tolerant, and has not been demonstrated as a whole.In the Archaean era, the earth was the product of the deflagration of five basic elements,earthMagmaThe residual volcanic explosion is the Five Basics Earth Tai Chi period of the Earth air mass period.To study cosmochemistry, we should first studyGeochemistryBecause there is a difference between geochemistry and cosmochemistry.The study of cosmochemistry and geochemistry is the basis for the study of the chemical structure of the Earth's human body, and cannot replace the living human bodydata。 Cosmic chemistry is the basis of material chemistry and life chemistry.It does not mean that life chemistry and geochemistry are branches of cosmochemistry. Cosmochemistry and geochemistry are two directions of the same problem.It is correct to study cosmochemistry and geochemistry under the guidance of Chinese phonology.PressHeliocentrismThere is no cosmochemical data.How can we correctly understand the mechanism of the 180 degree tilt of the Milky Way's half moon petalGalaxy；Without correct cosmochemistry andGeochemistryHow can there be correct earth human prevention science? The international view on geochemistry is only to find the source of geochemical elements on the earth.The life chemistry on the earth is based on the law that yin generates yang. All life on the earth, including human beings, are products of the earthMoonHolograms are life objects based on water and pentaacid on the earth.purealkaliNeither pure acid nor pure acid can produce living things.The international research on human beings on the earth is an imaginary research in fault culture, such as the absurd argument that human beings are from heaven.To study geochemistry is to study human body chemistry and cosmochemistry in order to study geochemistry.
research meaning
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The study of cosmochemistry is of great significance to the development of chemistry
Studying the origin of chemical elements is not only closely related to the formation and evolution of stars, but also related toBig Bang ofobservationGalaxyDifferent substances (such as hydrogen atomcarbon monoxideThe distribution of) can reveal the structure and localization of the Milky Way Galaxy.solar systemThe theory of origin and evolution must considerChemistry of the solar systemThe result of the research is that, on the one hand, we should use the acquired knowledge about the chemical composition of the solar system, and on the other hand, we must be able to explain the chemical composition of the solar system.The study of cosmochemistry is also of great significance to the development of chemistry. For example, ammonia was first found on the sun and later on the earth.Cosmic matter is in a state that is difficult to simulate on the earth, which provides a special "laboratory" for chemical research.yesInterstellar matterAnd cometsOrganic moleculeThe observation of and the study of organic molecules in meteorites have not only promoted the exploration of the origin of life, but also promoted the development of cosmochemistry.
Research tasks
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Cosmochemistry
The chemical composition of cosmic matter refers to the elementsisotope, molecules and minerals.One of the research tasks of cosmochemistry is to determine these components and determine their relative and absolute contents.There are two determination methods: one is direct sampling, such as measuring meteorite, lunar rock samplesCosmic dust、cosmic raysNuclear grade;The other is to measure theelectromagnetic radiationInCharacteristic spectral line。For example, for starsspectral analysis, YesInterstellar matterRadio, infraredvisible lightWavebandSpectrum analysis。Research shows that cosmic matter is composed ofPeriodic Table of Chemical ElementsNearly one hundred chemical elements and more than 280isotopic compositionOf.A number of minerals and molecules that have not yet been found on the earth have been found in cosmic matter.Another task of cosmochemistry is to study the chemical evolution of cosmic matter.There are several processes: first, some process (such as“Big Bang”）Generate elemental hydrogen, and then pass throughNucleosynthesisProcesses (such as star internal nucleosynthesisSupernovaExplosive nucleosynthesis, etc.) to generate other elements.The atoms of elements combine to form molecules on the surface of stars or in interstellar spacePlanetary systemThe lieutenant general will continue to evolve along two routes: molecules condense into dust, and the dust will gather to form planetesimals, which will then form planets and other celestial bodies;Some containcarbon、nitrogen, oxygenhydrogenAfter the molecules of other elements are generated in the interstellar cloud, they can generate complex molecules through the chemical evolution before lifeOther planetary systemsOn the planet)amino acid, protein, and finally lead to the emergence of life.The life of a star continuously ejects matter into interstellar space, and finally disintegrates intoInterstellar cloud；In turn, interstellar clouds condense to form various stars through a long process.
Development stage
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In the early days, people guessed the basic composition of the universe by intuition
Cosmochemistry
Human understanding of cosmic material chemistry has gone through several stages.In the early days, people guessed the basic composition of the universe by intuition.In the late Western Zhou Dynasty (7th century BC) in ancient ChinaFive Elements(gold, wood, water, fire, earth) to explain the composition of all things, and "yang qi" and "yin qi" to explain various changes in nature.ancient GreekIn the fourth century BC, people believed that water, air, fire and earth were the four basic elements of everything.
In the early 19th century, people carried out a lot of chemical analysis of minerals, rocks and other materials on the earth.In 1833,SwedenchemistBezeliusThe chemical composition of extraterrestrial matter was determined for the first time by chemical analysis of meteorites.In 1858, chemistBunsenAnd physicistsKirchhoffStudied and determined togetherSolar spectrum；In 1859, Kirchhoff successfully explainedFraunhofer lines (i.eAbsorption line）For the first time, the chemical composition of the sun (star) was proved.An important observation method of cosmochemistry——spectral analysisFrom then on.
Since the 1950s, with the development of atmospheric appearance measurement,Spectrum analysisThe waveband is composed ofvisible lightExtend to shootair waves, infrared, ultravioletX-ray、Gamma ray。In the 1960s, people found thatInterstellar molecule, directly landing on the moon to collect rock samples.In the 1970s, analytical instruments were sent to Mars.The research means of cosmochemistry are increasing day by day, and the research contents are constantly enriched.
