It has been suggested that Space dust be merged into this article or section. (Discuss)

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 refers to particles in space which are assemblages of a few molecules to tenth-millimeter-sized grains. Cosmic dust can be further distinguished by its astronomical location; for example: interplanetary dust, interstellar dust, comet dust, circumplanetary dust. This article covers bulk and radiative properties of cosmic dust, the dust particles' origins, end-fates, and specific locations in space. Image File history File links Please see the file description page for further information. ... Space Dust Space Dust is the dust thats floating in space. ... 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... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... Introductory Material Comet dust refers to cosmic dust that originates from a comet. ... wave f[o[Image:Light-wave. ...

Historically, cosmic dust used to be an annoyance to astronomers because of the way that the dust obscures the object that they wish to observe. When the field of infrared astronomy began, those so-called annoying dust particles were observed to be significant constituents of the Universe and found to be 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 that occurs when a star is nearing the end of its life, those particles are an essential part of the early stages of star formation, and they form planets around other stars. 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 the overall behavior of comets. The Pleiades star cluster A star is a massive body of plasma in outer space that is currently producing or has produced energy through nuclear fusion. ... In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime; the hundreds of thousands, millions or billions of years during which it emits light and heat. ... Star formation is the process by which gas in molecular clouds change into the ball of plasma we call a star. ... A planet is generally considered to be a relatively large mass of accreted matter in orbit around a star. ... The solar system comprises the Earths Sun and the retinue of celestial objects gravitationally bound to it. ... 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. ... Adjective Jovian Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... Adjective Uranian Atmospheric characteristics Atmospheric pressure 120 kPa (at the cloud level) Hydrogen 83% Helium 15% Methane 1. ... Adjective Neptunian Atmospheric characteristics Surface pressure ≫100 MPa Hydrogen - H2 80% ±3. ... Comet Hale-Bopp 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), math (fractal math), chemistry (chemical reactions on grain surfaces), meteoritics, as well as every branch of astronomy and astrophysics. While being multidisciplinary, the 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. Physics (from the Greek, φυσικός (physikos), natural, and φύσις (physis), nature) is the science of the natural world, which deals with the fundamental constituents of the universe, the forces they exert on one another, and the results of these forces. ... 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, encompassing all of space, which exerts a force on those particles that possess the property of electric charge, and is in turn affected by the presence and motion of such 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. ... A chemical reaction is a process that results in the interconversion of chemical substances [1]. The substance or substances initially involved in a chemical reaction are called reactants. ... Meteoritics is a science that deals with meteors and meteorites. ... Radio telescopes are among many different tools used by astronomers Astronomy (Greek: αστρονομία = άστρον + νόμος, astronomia = astron + nomos, literally, law of the stars) is the science of celestial objects and phenomena that originate outside the Earths atmosphere, such as stars, planets, comets, auroras, galaxies, and the cosmic background radiation. ... 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 astronomical objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ... The distribution of ionized hydrogen (known by astronomers as H II (aitch two) from old spectroscopic terminology) in the parts of the Galactic interstellar medium visible from the Earths northern hemisphere (from the Wisconsin H-Alpha Mapper Survey) In astronomy, the interstellar medium (or ISM) is the matter (interstellar... A Molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecular hydrogen, H2. ... A planetary system consists of at least one star and various orbiting objects (such as asteroids, comets, moons, and planets). ... The solar system comprises the Earths Sun and the retinue of celestial objects gravitationally bound to it. ...

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 physics, the photon (from Greek φως, phōs, meaning light) is the quantum of the electromagnetic field; for instance, light. ... The 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 via manipulation of observed data. ... A Plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation A solar coronal mass ejection blasts plasma throughout the solar system. ... Current flowing through a wire produces a magnetic field (B, labeled M here) around the wire. ...

Some bulk properties of cosmic dust

Smooth 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 dust grains and agreggates 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. General diffuse interstellar medium dust should be distinguished from dust grains in dense clouds, which should be distinguished from planetary rings dust, which should be distinguished from circumstellar dust, and so on. For example, grains in dense clouds have acquired a mantle of ice and the average dimensions are larger than those 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... Used in geology, building science and hydrogeology, the porosity of a porous medium (such as rock or sediment) is the proportion of the non-solid volume to the total volume of material, and is defined by the ratio: where Vp is the non-solid volume (pores and liquid) and Vm... The distribution of ionized hydrogen (known by astronomers as H II (aitch two) from old spectroscopic terminology) in the parts of the Galactic interstellar medium visible from the Earths northern hemisphere (from the Wisconsin H-Alpha Mapper Survey) In astronomy, the interstellar medium (or ISM) is the matter (interstellar... Interstellar cloud is the generic name given to accumulations of gas and dust in our galaxy. ...

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

Other dust composition variances are the following.

In circumstellar dust, astronomers have found signatures of CO, silicon carbide, amorphous silicate, polycyclic aromatic hydrocarbons, water ice, polyformaldehyde, just to name a few.

In the diffuse interstellar medium, there is a lot of evidence for silicate and carbon grains.

The elemental composition of IDPs (asteroidal and cometary) is one of three major types: chondritic, 60%, iron-sulfur-nickel, 30%, and mafic silicates, which are iron-magnesium-rich silicates, (i.e. olivine and pyroxene), 10%. ^{[1] [2]} An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... Chondrules in the chondrite Grassland. ...

Cometary dust is generally different (however some overlap exists) from asteroidal dust. Asteroidal dust resembles carbonaceous chondritic meteorites, and cometary dust resembles interstellar grains which can include elements silicates, polycyclic aromatic hydrocarbons, and water ice. Some carbonaceous chondrites. ... Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds that consist of fused aromatic rings and do not contain heteroatoms or carry substituents. ...

The densities of most stratospheric-captured IDPs range between 1 and 3 g/cm³, with an average density at about 2.0 g/cm³. ^[3]. A diagram is needed here to illustrate the stratosphere layer of the Earths atmosphere. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ...

Typical 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. ... ã ... 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 good argument can be made ^[4] that, given the gas-to-dust ratio in the interstellar medium, a large fraction of heavy elements (other then hydrogen and helium) must be tied up in dust grains, the assembled elements for the molecules most likely being carbon, nitrogen, oxygen, magnesium, silicon, sulphur, iron, and compounds of these.

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. wave f[o[Image:Light-wave. ... Cross section may refer to the following In geometry, Cross section is the intersection of a 3-dimensional body with a plane. ... The wavelength is the distance between repeating units of a wave pattern. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... The emissivity of a material (usually written ) is the ratio of energy radiated 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. ... In particle physics, scattering is a class of phenomena by which particles are deflected by collisions with other particles. ... Look up absorption in Wiktionary, the free dictionary Absorption may refer to: In physics: absorption (chemistry) - absorption of particles of gas or liquid in liquid or solid material as studied in physical chemistry absorption (optics) - absorption of photons by a material Absorption (acoustics) - absorption of sound waves by a material...

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. To meet Wikipedias quality standards, this article or section may require cleanup. ...

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. In astronomy, reflection nebulae are clouds of dust which are simply reflecting the light of a nearby star or stars. ...

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. A carbon star is a red giant (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 and other carbon compounds. ... 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. ...

How do astronomers know that that dust is formed in the envelopes of late-evolved stars? They know from their observations. An observed (infrared) 9.7 micrometre emission silicate signature for cool evolved (oxygen-rich giant) stars. And an observed (infrared) 11.5 micrometre emission silicon carbide signature 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. ^{[5] [6]}

How do astronomers know that dust wasn't formed in interstellar space? They know because the 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 universe for interstellar grains to form ^[7]. 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. {alternateuses}} 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. ...

Dust grain destruction

How are the interstellar grains destroyed? There are several ultraviolet processes which lead to grain "explosions" ^{[8] [9]}. 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, as well. ^[10] Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft X-rays. ... Sputtering is a physical 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 then some grains form sometime 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. Protostar is a period after clouds of hydrogen, helium and dust begin to contract and before the star reaches the main sequence. ... T Tauri stars are a class of variable stars named after their prototype - T Tauri. ...

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 molecular hydrogen, H2. ...

Some "dusty" clouds in the universe

Our solar sytem 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 the following classifications:

• diffuse nebula
• infrared (IR) reflection nebula
• supernova remnant
• molecular cloud
• HII regions
• photodissociation regions

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). In astronomy, diffuse nebulae is the common term for both reflection nebulae and emission nebulae. ... In astronomy, reflection nebulae are clouds of dust which are simply reflecting the light of a nearby star or stars. ... 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 molecular hydrogen, H2. ... NGC 604, a giant H II region in the Triangulum Galaxy. ... The entire Orion Nebula in visible light Optical images reveal clouds of gas and dust in the Orion Nebula; an infrared image (right) reveals the new stars shining within. ... The Crab Pulsar. ... Synchrotron radiation is electromagnetic radiation, similar to cyclotron radiation, but generated by the acceleration of ultrarelativistic (i. ...

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 Pulsar. ... Messier Object 8, the Lagoon Nebula. ... Perhaps one of the most famous and easily recognized space objects, the Eagle Nebula (also known as Messier Object 16, M16 or NGC 6611) is a young open cluster of stars in the constellation Serpens. ... 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 entire Orion Nebula in visible light Optical images reveal clouds of gas and dust in the Orion Nebula; an infrared image (right) reveals the new stars shining within. ... 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

at

• The National Space Sciences Data Center (NSSDC)
• CDS Online Catalogs

References

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

↑ 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.

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

↑  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.

↑ 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).

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

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