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Encyclopedia > Cosmic dust
Porous chondrite interplanetary dust particle. Courtesy of E.K. Jessberger, Institut für Planetologie, Münster, Germany, and Don Brownlee, University of Washington, Seattle, under a cc-a-2.5 license.

Cosmic dust is a type of dust composed of particles in space which are a few molecules to 0.1 mm in size. Cosmic dust can be further distinguished by its astronomical location; for example: intergalactic dust, interstellar dust, circumplanetary dust, dust clouds around other stars, and the major interplanetary dust components to our own zodiacal dust complex (seen in visible light as the zodiacal light): Comet dust, asteroidal dust plus some of the less significant contributors: Kuiper belt dust, interstellar dust passing through our solar system, and beta meteoroids. Space dust may refer to: Space dust, another name for cosmic dust, particles in space which range in size from a few molecules to 0. ... Image File history File links Download high resolution version (876x583, 198 KB) Summary This is a scanning electron micrscope image of a interplanetary dust particle that has roughly chondritic elemental composition and is highly rough (chondritic porous: CP). CP types are usually aggregates of large numbers of sub-micrometer grains... Image File history File links Download high resolution version (876x583, 198 KB) Summary This is a scanning electron micrscope image of a interplanetary dust particle that has roughly chondritic elemental composition and is highly rough (chondritic porous: CP). CP types are usually aggregates of large numbers of sub-micrometer grains... Look up dust in Wiktionary, the free dictionary. ... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... Interplanetary dust cloud The interplanetary dust cloud has been studied for many years in order to understand its nature, origin, and relationship to solar systems (our own, as well as extrasolar systems). ... The zodiacal light in the eastern sky before the beginning of morning twilight. ... Introductory Material Comet dust refers to cosmic dust that originates from a comet. ... The Kuiper belt, derived from data from the Minor Planet Center. ...


Cosmic dust was once solely an annoyance to astronomers, as it obscures objects they wish to observe. When infrared astronomy began, those so-called annoying dust particles were observed to be significant and vital components of astrophysical processes. Infrared astronomy is the branch of astronomy and astrophysics which deals with objects visible in infrared (IR) radiation. ...


For example, the dust can drive the mass loss when a star is nearing the end of its life, play a part in the early stages of star formation, and form planets. In our own solar system, dust plays a major role in the zodiacal light, Saturn's B Ring spokes, the outer diffuse planetary rings at Jupiter, Saturn, Uranus and Neptune, the resonant dust ring at the Earth, and comets. STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... In astronomy, stellar evolution is the sequence of radical changes that a star undergoes during its lifetime (the time in which it emits light and heat). ... Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. ... This article is about the astronomical term. ... This article is about the Solar System. ... The zodiacal light in the eastern sky before the beginning of morning twilight. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... Categories: Astronomy stubs ... A spoke is one of some number of rods radiating from the center of a wheel (the hub where the axle connects), connecting the hub with the round traction surface. ... A planetary ring is a ring of dust and other small particles orbiting around a planet in a flat disc-shaped region. ... For other uses, see Jupiter (disambiguation). ... For other uses, see Uranus (disambiguation). ... For other uses, see Neptune (disambiguation). ... Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ...


The study of dust is a many-faceted research topic that brings together different scientific fields: physics (solid-state, electromagnetic theory, surface physics, statistical physics, thermal physics), (fractal mathematics), chemistry (chemical reactions on grain surfaces), meteoritics, as well as every branch of astronomy and astrophysics. These disparate research areas can be linked by the following theme: the cosmic dust particles evolve cyclically; chemically, physically and dynamically. The evolution of dust traces out paths in which the universe recycles material, in processes analogous to the daily recycling steps with which many people are familiar: production, storage, processing, collection, consumption, and discarding. Observations and measurements of cosmic dust in different regions provide an important insight into the universe's recycling processes; in the clouds of the diffuse interstellar medium, in molecular clouds, in the circumstellar dust of young stellar objects, and in planetary systems such as our own solar system, where astronomers consider dust as in its most recycled state. The astronomers accumulate observational ‘snapshots’ of dust at different stages of its life and, over time, form a more complete movie of the universe's complicated recycling steps. A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Solid-state physics, the largest branch of condensed matter physics, is the study of rigid matter, or solids. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... Statistical physics, one of the fundamental theories of physics, uses methods of statistics in solving physical problems. ... Thermal physics is the combined study of thermodynamics, statistical mechanics, and kinetic theory. ... The boundary of the Mandelbrot set is a famous example of a fractal. ... For other uses, see Chemical reaction (disambiguation). ... Meteoritics is a science that deals with meteors and meteorites. ... For other uses, see Astronomy (disambiguation). ... Spiral Galaxy ESO 269-57 Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ... The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. ... A molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen (H2). ... Young stellar object (YSO) denotes a star in its early stage of evolution. ... A planetary system consists of at least one star and various orbiting objects (such as asteroids, comets, moons, and planets). ... This article is about the Solar System. ...


The detection of cosmic dust points to another facet of cosmic dust research: dust acting as photons. Once cosmic dust is detected, the scientific problem to be solved is an inverse problem to determine what processes brought that encoded photon-like object (dust) to the detector. Parameters such the particle's initial motion, material properties, intervening plasma and magnetic field determined the dust particle's arrival at the dust detector. Slightly changing any of these parameters can give significantly different dust dynamical behavior. Therefore one can learn about where that object came from, and what is (in) the intervening medium. In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... An inverse problem is the task that often occurs in many branches of science and mathematics where the values of some model parameter(s) must be obtained from the observed data. ... For other uses, see Plasma. ... Magnetic field lines shown by iron filings In physics, the space surrounding moving electric charges, changing electric fields and magnetic dipoles contains a magnetic field. ...

Contents

Detection methods

Cosmic dust can be detected by indirect methods utilizing the radiative properties of cosmic dust. Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ...


Cosmic dust can also be detected directly ('in-situ') using a variety of collection methods and from a variety of collection locations. At the Earth, generally, an average of 40 tons per day of extraterrestrial material falls to the Earth label. The Earth-falling dust particles are collected in the Earth's atmosphere using plate collectors under the wings of stratospheric-flying NASA airplanes and collected from surface deposits on the large Earth ice-masses (Antarctica and Greenland / the Arctic) and in deep-sea sediments. Don Brownlee at the University of Washington in Seattle first reliably identified the extraterrestrial nature of collected dust particles in the later 1970s. Another source is the meteorites, which contain stardust extracted from them (see below). Stardust grains are solid refractory pieces of individual presolar stars. They are recognized by their extreme isotopic compositions, which can only be isotopic compositions within evolved stars, prior to any mixing with the interstellar medium. These grains condensed from the stellar matter as it cooled while leaving the star. This article is about the American space agency. ... Airplane and Aeroplane redirect here. ...


In interplanetary space, dust detectors on planetary spacecraft have been built and flown , some are presently flying, and more are presently being built to fly. The large orbital velocities of dust particles in interplanetary space (typically 10-40 km/s) make intact particle capture problematic. Instead, in-situ dust detectors are generally devised to measure parameters associated with the high-velocity impact of dust particles on the instrument, and then derive physical properties of the particles (usually mass and velocity) through laboratory calibration (i.e. impacting accelerated particles with known properties onto a laboratory replica of the dust detector). Over the years dust detectors have measured, among others, the impact light flash, acoustic signal and impact ionisation. Recently the dust instrument on Stardust captured particles intact in low-density aerogel. An artists rendering of Stardust (NASA image) The Stardust capsule with cometary and interstellar samples landed at the U.S. Air Force Utah Test and Training Range at 10:10 UTC (15 January 2006) in the Bonneville Salt Flats. ...


Dust detectors in the past flew on the HEOS-2, Helios, Pioneer 10, Pioneer 11, Giotto, and Galileo space missions, on the Earth-orbiting LDEF, Eureca, and Gorid satellites, and some scientists have utilized the Voyager 1,2 spacecraft as giant Langmuir probes to directly sample the cosmic dust. Presently dust detectors are flying on the Ulysses, Cassini, Proba, Rosetta, Stardust, and the New Horizons spacecraft. The collected dust at Earth or collected further in space and returned by sample-return space missions is then analyzed by dust scientists in their respective laboratories all over the world. One large storage facility for cosmic dust exists at the NASA Houston JSC. For other uses, see Helios (disambiguation). ... Pioneer 10 was the first spacecraft to travel through the asteroid belt, and was the first spacecraft to make direct observations of Jupiter. ... Position of Pioneer 10 and 11 Pioneer 11 was the second mission to investigate Jupiter and the outer solar system and the first to explore the planet Saturn and its main rings. ... In this artists concept, Giotto points its white high-gain antenna dish towards earth with the ring of solar cells facing the sun. ... Galileo is prepared for mating with the IUS booster Galileo being deployed after being launched by the Space Shuttle Atlantis on the STS-34 mission Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. ... NASAs Long Duration Exposure Facility, a school-bus sized cylindrical space experiment rack, exposed various material samples to outer space for about 5. ... Voyager Project redirects here. ... A Langmuir probe is a device named after Nobel Prize winning physicist Irving Langmuir which is used to determine the electron temperature, electron density, and plasma potential. ... Ulysses spacecraft Ulysses is an unmanned probe designed to study the Sun at all latitudes. ... This is an artists concept of Cassini during the Saturn Orbit Insertion (SOI) maneuver, just after the main engine has begun firing. ... Conceptual drawing of the Rosetta orbiter and Philae lander Rosetta is a European Space Agency-led unmanned space mission launched in 2004 intended to study the comet 67P/Churyumov-Gerasimenko. ... An artists rendering of Stardust (NASA image) The Stardust capsule with cometary and interstellar samples landed at the U.S. Air Force Utah Test and Training Range at 10:10 UTC (15 January 2006) in the Bonneville Salt Flats. ... New Horizons on the launchpad New Horizons is a robotic spacecraft mission conducted by NASA. It is expected to be the first spacecraft to fly by and study the dwarf planet Pluto and its moons, Charon, Nix and Hydra. ...


Radiative properties of cosmic dust

A dust particle interacts with electromagnetic radiation in a way that depends on its cross section, the wavelength of the electromagnetic radiation, and on the nature of the grain: its refractive index, size, etc. The radiation process for an individual grain is called its emissivity, dependent on the grain's efficiency factor. Furthermore, we have to specify whether the emissivity process is extinction, scattering, or absorption. In the radiation emission curves, several important signatures identify the composition of the emitting or absorbing dust particles. Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ... A 3-D view of a beverage-can stove with a cross section in yellow. ... The wavelength is the distance between repeating units of a wave pattern. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... The emissivity of a material (usually written ) is the ratio of energy radiated by the material to energy radiated by a black body at the same temperature. ... Extinction is a term used in astronomy to describe the absorption of light from astronomical objects by matter between them and the observer. ... Scattering is a general physical process whereby some forms of radiation, such as light, sound or moving particles, for example, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which it passes. ... Look up absorption in Wiktionary, the free dictionary. ...


Dust particles can scatter light nonuniformly. Forward-scattered light means that light is redirected slightly by diffraction off its path from the star/sunlight, and back-scattered light is reflected light. The intensity pattern formed on a screen by diffraction from a square aperture Diffraction refers to various phenomena associated with wave propagation, such as the bending, spreading and interference of waves passing by an object or aperture that disrupts the wave. ...


The scattering and extinction ("dimming") of the radiation gives useful information about the dust grain sizes. For example, if the object(s) in one's data is many times brighter in forward-scattered visible light than in back-scattered visible light, then we know that a significant fraction of the particles are about a micrometer in diameter.


The scattering of light from dust grains in long exposure visible photographs is quite noticeable in reflection nebulas, and gives clues about the individual particle's light-scattering properties. In x-ray wavelengths, many scientists are investigating the scattering of x-rays by interstellar dust, and some have suggested that astronomical x-ray sources would possess diffuse haloes, due to the dust. The Witch Head reflection nebula (IC2118), about 1000 light years from earth, is associated with the bright star Rigel in the constellation Orion. ...


Stardust

Stardust grains are contained within meteorites, from which they are extracted in terrestrial laboratories. So-called carbonaceous chondrites are especially fertile reservoirs of stardust. Each stardust grain existed before the earth was formed. The meteorites have preserved the previously interstellar stardust grains since that time. Stardust is a scientific term rather than a poetic one, referring to refractory dust grains that condensed from cooling ejected gases from individual presolar stars. Many different types of stardust have been identified by laboratory measurements of the highly unusual isotopic composition of the chemical elements that comprise each stardust grain. Many new aspects of nucleosynthesis have been discovered from those isotopic ratios [1]. The following website http://www.dtm.ciw.edu/lrn/psg_main.html contains an excellent introduction to, and photographs of, many differing types of stardust. An important property of stardust is the hard, refractory, high-temperature nature of the grains.:) Prominent are silicon carbide, graphite, aluminum oxide, aluminum spinel, and other such grains that would condense at high temperature from a cooling gas, such as in stellar winds or in the decompression of the inside of a supernova. They differ greatly from the solids formed at low temperature within the interstellar medium. Also important are their extreme isotopic compositions, which are expected to exist nowhere in the interstellar medium. This also suggests that the stardust condensed from the gases of individual stars before the isotopes could be diluted by mixing with the interstellar medium. These allow the source stars to be identified. For example, the heavy elements within the SiC grains are almost pure s process isotopes, fitting their condensation within AGB star red giant winds inasmuch as the AGB stars are the main source of s process nucleosynthesis and have atmospheres observed by astronomers to be highly enriched in dredged-up s process elements. Another dramatic example comes from the supernova condensates, usually shortened by acronym to SUNOCON to distinguish them from other stardust condensed within stellar atmospheres. SUNOCONs show evidence that they condensed containing abundant radioactive 44Ti, having 65 yr halflife. It was thus still alive when the SUNOCON condensed within the expanding supernova interior but would have been extinct after mixing with the interstellar gas. Its discovery proved the prediction from 1975 to identify SUNOCONs in this way. But SiC SUNOCONs are only about 1% as numerous as are SiC stardust. Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons (protons and neutrons). ... Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ... This article or section does not cite its references or sources. ... Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons (protons and neutrons). ...


Exciting as stardust is, it is but a modest fraction of the condensed cosmic dust. It seems that stardust is less than 0.1% of the mass of total interstellar solids. Its interest lies in the new information that it has brought to the sciences of stellar evolution and nucleosynthesis. In astronomy, stellar evolution is the sequence of radical changes that a star undergoes during its lifetime (the time in which it emits light and heat). ... Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons (protons and neutrons). ...


A fascinating aspect to human culture is the study within terrestrial laboratories of solids that existed before the earth existed. This was once thought impossible, especially in the decades when cosmochemists were confident that the solar system began as a hot gas virtually devoid of any remaining solids, which would have been vaporized by high temperature. The very existence of stardust shows that that historic picture was incorrect.


Some bulk properties of cosmic dust

Smooth chondrite interplanetary dust particle. Courtesy of E.K. Jessberger, Institut für Planetologie, Münster, Germany, and on Brownlee, University of Washington, Seattle, under a cc-a-2.5 license.
Smooth chondrite interplanetary dust particle. Courtesy of E.K. Jessberger, Institut für Planetologie, Münster, Germany, and on Brownlee, University of Washington, Seattle, under a cc-a-2.5 license.

Cosmic dust is made of dust grains and aggregates of dust grains. These particles are irregularly-shaped with porosity ranging from fluffy to compact. The composition, size, and other properties depends on where the dust is found, and conversely, a compositional analysis of a dust particle can reveal the much about the dust particle's origin. General diffuse interstellar medium dust, dust grains in dense clouds, planetary rings dust, and circumstellar dust, are each different in their characteristics. For example, grains in dense clouds have acquired a mantle of ice and on average are larger than dust particles in the diffuse interstellar medium. Interplanetary dust particles (IDPs) are generally larger still. Image File history File links Smooth_chondriteIDP.jpg Summary This is a scanning electron micrscope image of an interplanetary dust particle that has roughly chondritic elemental composition and is highly smooth (chondritic smooth: CS). CS types are usually aggregates of large numbers of sub-micrometer grains, clustered in a random open... Image File history File links Smooth_chondriteIDP.jpg Summary This is a scanning electron micrscope image of an interplanetary dust particle that has roughly chondritic elemental composition and is highly smooth (chondritic smooth: CS). CS types are usually aggregates of large numbers of sub-micrometer grains, clustered in a random open... Porosity is a measure of the void spaces in a material, and is measured as a fraction, between 0–1, or as a percentage between 0–100%. The term porosity is used in multiple fields including manufacturing, earth sciences and construction. ... The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. ... Interstellar cloud is the generic name given to accumulations of gas and dust in our galaxy. ... A planetary ring is a ring of dust and other small particles orbiting around a planet in a flat disc-shaped region. ...

Major elements of 200 stratospheric interplanetary dust particles. Courtesy of Thomas Stephan, Institut für Planetologie, Münster, Germany, under a cc-a-2.5 license.

Most of the influx of extraterrestrial matter that falls onto the Earth is dominated by meteoroids with diameters in the range 50 to 500 micrometers, of average density 2.0 g/cm³ (with porosity about 40%). The densities of most stratospheric-captured IDPs range between 1 and 3 g/cm³, with an average density at about 2.0 g/cm³. Image File history File links Download high-resolution version (814x563, 213 KB) The largest data set for major elements (Schramm et al. ... Image File history File links Download high-resolution version (814x563, 213 KB) The largest data set for major elements (Schramm et al. ... Atmosphere diagram showing stratosphere. ... For other uses, see Density (disambiguation). ...


label.


Other specific dust properties:

  • In circumstellar dust, astronomers have found molecular signatures of CO, silicon carbide, amorphous silicate, polycyclic aromatic hydrocarbons, water ice, and polyformaldehyde, among others. (In the diffuse interstellar medium, there is evidence for silicate and carbon grains.)
  • Cometary dust is generally different (with overlap) from asteroidal dust. Asteroidal dust resembles carbonaceous chondritic meteorites, and cometary dust resembles interstellar grains, which can include the elements: silicates, polycyclic aromatic hydrocarbons, and water ice.

Introductory Material Comet dust refers to cosmic dust that originates from a comet. ... Some carbonaceous chondrites. ... Interstellar cloud is the generic name given to accumulations of gas and dust in our galaxy. ... An illustration of typical polycyclic aromatic hydrocarbons. ...

Dust grain formation

The large grains start with the silicate particles forming in the atmospheres of cool stars, and carbon grains in the atmospheres of cool carbon stars. Stars, which have evolved off the main sequence, and which have entered the giant phase of their evolution, are a major source of dust grains in galaxies. Star dust, sung and written in the popular media, is a colloquial term referring to the birthplace of most dust grains in the Universe. If one indeed traces the origin of the elements out of which our bodies are made, we are star dust. A carbon star is a late type giant star similar to the red giants (or occasionally red dwarf) star whose atmosphere contains more carbon than oxygen; the two elements combine in the upper layers of the star, forming carbon monoxide, which consumes all the oxygen in the atmosphere, leaving carbon... Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ... Giant star is a star that has stopped fusing hydrogen in its core. ...


Astronomers know that the dust is formed in the envelopes of late-evolved stars from specific observational signatures. An (infrared) 9.7 micrometre emission silicate signature is observed for cool evolved (oxygen-rich giant) stars. And an (infrared) 11.5 micrometre emission silicon carbide signature is observed for cool evolved (carbon-rich giant) stars. These help provide evidence that the small silicate particles in space came from the outer envelopes (ejecta) of these stars. label label


It is believed that conditions in interstellar space are generally not suitable for the formation of silicate cores. The arguments are that: given an observed typical grain diameter a, the time for a grain to attain a, and given the temperature of interstellar gas, it would take considerably longer than the age of the universe for interstellar grains to form label. Furthermore, grains are seen to form in the vicinity of nearby stars in real-time, meaning in a) nova and supernova ejecta, and b) R Coronae Borealis, which seem to eject discrete clouds containing both gas and dust. Artists conception of a white dwarf star accreting hydrogen from a larger companion A nova (pl. ... Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ...


Most dust in our solar system is highly processed dust, recycled from the material out of which our solar system formed and subsequently collected in the planetesimals, and leftover solid material (for example: comets and asteroids), and reformed in each of those bodies' collisional lifetimes. During our solar system's formation history, the most abundant element was (and still is) H2. The metallic elements: magnesium, silicon, and iron, which are the principal ingredients of rocky planets, condensed into solids at the highest temperatures. The range of elements of the solar nebula between H2 and (Mg, Si, Fe) is not known well (Wood, J., 1999). Some molecules such as CO, N2, NH3, and free oxygen, existed in a gas phase. Some molecules, for example, graphite (C) and SiC condensed into solid grains. Some molecules also formed complex organic compounds and some molecules formed frozen ice mantles, of which either could coat the "refractory" (Mg, Si, Fe) grain cores.


The formation of these molecules was determined, in large part, by the temperature of the solar nebula. Since the temperature of the solar nebula decreased with heliocentric distance, scientists can infer a dust grain's origin(s) with knowledge of the grain's materials. Some materials could only have been formed at high temperatures, while other grain materials could only have been formed at much lower temperatures. The materials in a single interplanetary dust particle often show that the grain elements formed in different locations and at different times in the solar nebula. Most of the matter present in the original solar nebula has since disappeared; drawn into the Sun, expelled into interstellar space, or reprocessed, for example, as part of the planets, asteroids or comets.


Due to their highly-processed nature, IDPs are fine-grained mixtures of thousands to millions of mineral grains and amorphous components. We can picture an IDP as a "matrix" of material with embedded elements which were formed at different times and places in the solar nebula and before our solar nebula's formation. Examples of embedded elements in cosmic dust are GEMS, chondrules, and CAIs. An amorphous solid is a solid in which there is no long-range order of the positions of the atoms. ... This article or section does not cite any references or sources. ... Glass with Embedded Metal and Sulfides (GEMS) are tiny spheroids in cosmic dust particles with bulk compositions that are approximately chondritic. ... Chondrules in the chondrite Grassland. ... CAIs are the Calcium-Aluminum-Inclusions that one sometimes finds between the chondrules in cosmic dust. ...


A Dusty Trail from the Solar Nebula to Earth

A dusty trail from the early solar system to carbonaceous dust today. Courtesy of Amara Graps, Planetary Science Institute, Tucson, Arizona, released to the public domain.
A dusty trail from the early solar system to carbonaceous dust today. Courtesy of Amara Graps, Planetary Science Institute, Tucson, Arizona, released to the public domain.

The arrows in the adjacent diagram show one possible path from a collected interplanetary dust particle back to the early stages of the solar nebula. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...


We can follow the trail to the right in the diagram to the IDPs that contain the most volatile and primitive elements. The trail takes us first from interplanetary dust particles to chondritic interplanetary dust particles. Planetary scientists classify chondritic IDPs in terms of their diminishing degree of oxidation so that they fall into three major groups: the carbonaneous, the ordinary, and the enstatite chondrites. As the name implies, the carbonaceous chondrites are rich in carbon, and many have anomalies in the isotopic abundances of H, C, N, and O (Jessberger, 2000). From the carbonaceous chondrites, we follow the trail to the most primitive materials. They are almost completely oxidized and contain the most low condensation temperature elements ("volatile" elements) and the largest amount of organic compounds. Therefore, dust particles with these elements are thought to be formed in the early life of our solar system. Why? The volatile elements have never seen temperatures above about 500 K, therefore, one can conclude that the IDP grain "matrix" consists of some very primitive solar system material. Such a scenario is true in the case of comet dust (Gruen, 1999).


We can learn more about these particles' origin, by examining their surfaces. If we examine, in the laboratory, dust particles' density of solar flare tracks, their amorphous rims, and the spallogenic isotopes from cosmic rays (Flynn, 1996), then we have good clues for how long a particle has been travelling in space. Nuclear damage tracks are caused by the ion flux from solar flares. Solar wind ions impacting on the particle's surface produce amorphous radiation damaged rims on the particle's surface. And spallogenic nuclei are produced by galactic and solar cosmic rays. A dust particle that originates in the Kuiper Belt at 40AU would have many more times the density of tracks, thicker amorphous rims and higher integrated doses than a dust particle originating in the main-asteroid belt.


Dust grain destruction

How are the interstellar grains destroyed? There are several ultraviolet processes which lead to grain "explosions" label label. In addition, evaporation, sputtering (when an atom or ion strikes the surface of a solid with enough momentum to eject atoms from it), and grain-grain collisions have a major influence on the grain size distribution. label For other uses, see Ultraviolet (disambiguation). ... Sputtering is a physical vapor deposition, PVD process whereby atoms in a solid target material are ejected into the gas phase due to bombardment of the material by energetic ions. ...


These destructive processes happen in a variety of places. Some grains are destroyed in the supernovae/novae explosion (and others are formed afterwards). Some of the dust is ejected out of the protostellar disk in the strong stellar winds that occur during a protostar's active T Tauri phase and may be destroyed when passing through shocks, e.g. in Herbig-Haro objects. Plus there are some gas-phase processes in a dense cloud where ultraviolet photons eject energetic electrons from the grains into the gas. A Protostar is an object that forms by contraction out of the gas of a giant molecular cloud in the interstellar medium. ... Drawing of a T-Tauri star with a circumstellar accretion disk T Tauri stars are a class of variable stars named after their prototype - T Tauri. ... Herbig-Haro object HH47, imaged by the Hubble Space Telescope. ...


Dust grains incorporated into stars are also destroyed, but only a relatively small fraction of the mass of a star-forming cloud actually ends up in stars. This means a typical grain goes through many molecular clouds and has mantles added and removed many times before the grain core is destroyed. A molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen (H2). ...


Some "dusty" clouds in the universe

Our solar system has its own interplanetary dust cloud; extrasolar systems too. Interplanetary dust cloud The interplanetary dust cloud has been studied for many years in order to understand its nature, origin, and relationship to solar systems (our own, as well as extrasolar systems). ...


There are different types of nebulae with different physical causes and processes. One might see these classifications:

Distinctions between those types of nebula are that different radiation processes are at work. For example, H II regions, like the Orion Nebula, where a lot of star-formation is taking place, are characterized as thermal emission nebulae. Supernova remnants, on the other hand, like the Crab Nebula, are characterized as nonthermal emission (synchrotron radiation). The Orion Nebula, a famous emission nebula. ... The Witch Head reflection nebula (IC2118), about 1000 light years from earth, is associated with the bright star Rigel in the constellation Orion. ... The Crab Nebula is an expanding cloud of gas created by the 1054 supernova. ... A molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen (H2). ... NGC 604, a giant H II region in the Triangulum Galaxy. ... The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated south of Orions Belt. ... The Crab Nebula (catalogue designations M 1, NGC 1952, Taurus A) is a supernova remnant in the constellation of Taurus. ... General Electric synchrotron accelerator built in 1946, the origin of the discovery of synchrotron radiation. ...


Some of the better known dusty regions in the universe are the diffuse nebula in the Messier catalog, for example: M1, M8, M16, M17, M20, M42, M43 Messier Catalog The Crab Nebula (catalogue designations M 1, NGC 1952, Taurus A) is a supernova remnant in the constellation of Taurus. ... Messier Object 8, the Lagoon Nebula. ... The Eagle Nebula (also known as Messier Object 16, M16 or NGC 6611), perhaps one of the most famous and easily recognized space objects, is a young open cluster of stars in the constellation Serpens, discovered by Jean-Philippe de Cheseaux in 1745-46. ... The Omega Nebula (also known as the Swan Nebula, the Horseshoe Nebula, the Lobster Nebula, M17, and NGC 6618) is an H II region in the constellation Sagittarius. ... The Trifid Nebula (also known as M20 and NGC 6514) is an H II region at right ascension 18h 02. ... The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated south of Orions Belt. ... De Mairans Nebula (also known as M43 and NGC 1982) is an H II region in the Orion constellation. ...


Some larger 'dusty' catalogs that you can access from the NSSDC, CDS, and perhaps other places are:

  • Sharpless (1959) A Catalogue of HII Regions
  • Lynds (1965) Catalogue of Bright Nebulae
  • Lunds (1962) Catalogue of Dark Nebulae
  • van den Bergh (1966) Catalogue of Reflection Nebulae
  • Green (1988) Rev. Reference Cat. of Galactic SNRs

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References

  1. ^ D. D. Clayton and L. R. Nittler (2004). "Astrophysics with Presolar Stardust". ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS 42: 39-78. 

^backEvans94  Evans, Aneurin (1994). The Dusty Universe. Ellis Horwood. 


^backGreen76 Greenberg, J. M. (January 1976). "Radical formation, chemical processing, and explosion of interstellar grains". Astrophysics and Space Science (Symposium on Solid State Astrophysics, University College, Cardiff, Wales, July 9-12, 1974.) 139: 9-18. 


^backGruen99 Gruen, Eberhard (1999). "Interplanetary Dust and the Zodiacal Cloud". Encyclopedia of the Solar System: XX. 


^backJess92  Jessberger, Elmar K.; Bohsung, Joerg; Chakaveh, Sepideh; Traxel, Kurt (August 1992). "The volatile element enrichment of chondritic interplanetary dust particles". Earth and Planetary Science Letters 112, No. 1-4: 91-99. 


^backdHend85 d'hendecourt, L. B.; Allamandola, L. J.; Greenberg, J. M. (November 1985). "The volatile element enrichment of chondritic interplanetary dust particles". Astronomy and Astrophysics 152: 130-150.  Greenberg, 1976).


^backHumph72 Humphreys, Roberta M.; Strecker, Donald W.; Ney, E. P. (February 1972). "Spectroscopic and Photometric Observations of M Supergiants in Carina". Astrophysical Journal 172: 75. 


^Lein90 Leinert C.; Gruen E. (1990). "Interplanetary Dust". Physics and Chemistry in Space (R. Schwenn and E. Marsch eds.): 204--275, Springer-Verlag. 


^backLove94 Love S. G., Joswiak D. J., and Brownlee D. E. (August 1992). "Densities of stratospheric micrometeorites". Icarus 111: 227-236. 


External links

  • Cosmic Dust Glossary

  Results from FactBites:
 
cosmic dust (642 words)
Interstellar dust particles strongly absorb, scatter, and polarize visible light at wavelengths comparable to their size, reemitting the light in the far-infrared region of the spectrum.
Elliptical galaxies have less dust than our galaxy (but are not dust-free), while some galaxies are experiencing such tremendous episodes of star formation that the dust in them converts nearly all the visible light into infrared, resulting in an ultra-luminous infrared galaxy.
"Cosmic dust in manganese nodules" (Jacques Jedwab, Free University of Brussels)
Cosmic dust - Wikipedia, the free encyclopedia (1628 words)
Cosmic dust used to be an annoyance to astronomers because of the way that the dust obscures the object that they wish to observe.
Cosmic dust is dust grains and agreggates of dust grains.
A dust particle interacts with electromagnetic radiation in a way that depends on its cross section, the wavelength of the electromagnetic radiation, and on the nature of the grain: its refractive index, size, etc. The radiation process for an individual grain is called its emissivity, dependent on the grain's efficiency factor.
  More results at FactBites »

 
 

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