Complementary Laboratory Measurements of Individual Interplanetary Dust Particles

1985 ◽  
Vol 85 ◽  
pp. 149-155
Author(s):  
A. Fahey ◽  
K.D. McKeegan ◽  
S.A. Sandford ◽  
R.M. Walker ◽  
B. Wopenka ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Secondary Ion Mass Spectrometry ◽  
Molecular Spectroscopy ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Infrared Transmission ◽  
Interplanetary Dust Particles ◽  
Secondary Ion ◽  
Complementary Analysis ◽  
Solar Flare Tracks

AbstractComplementary analysis techniques including electron microscopy (SEM/EDX and TEM), molecular spectroscopy (FTIR and Raman), and secondary ion mass spectrometry (SIMS), are used to study individual dust particles collected in the stratosphere. Large deuterium enrichments and solar flare tracks show that most particles in the “chondritic” class are interplanetary dust particles (IDPs). Infrared transmission spectra of most IDPs fall into three major classes (layer-lattice silicates, pyroxenes and olivines). TEM and Raman measurements confirm this classification. The IR spectra show certain similarities to spectra observed in comets and protostars. In particular the 6.8 μm features observed in protostars and IDPs may have a common origin. Large D excesses are observed in IDPs of the first two IR classes. The correlation of D/H ratios with the C concentration indicates a carbonaceous carrier of the excess D. The D enrichments and IR spectra provide links to interstellar molecular cloud material.

Comparative mineral chemistry of IDPs, micrometeorites and meteorite matrices

1992 ◽  
Vol 50 (2) ◽  
pp. 1718-1719
Author(s):  
Wolfgang Klöck
Keyword(s):  
Mineral Chemistry ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Type I ◽  
Interplanetary Dust Particles ◽  
Mineral Phases ◽  
Mineral Compositions ◽  
Almost All ◽  
Iron Manganese ◽  
Solar Flare Tracks

Chondritic porous aggregates are one subclass of Interplanetary Dust Particles (IDPs). The remaining classes presently identified are hydrated IDPs consisting mainly of serpentine or smectite. We have been investigating mineral compositions in these types of IDPs, in micrometeorites from Antarctica and compared them to mineral compositions in finegrained meteorite materials, like matrices and chondrule dust mantles from several meteorite classes. Based on our mineral analyses we subdivide anhydrous IDPs into three types. Type I contains olivines and/or pyroxenes having very variable iron contents from Fa 0 to Fa 35 and Fs 0 to Fs 30. Mineral phases in these particles are truly unequilibrated. Mineral grains in several particles of type I IDPs were found to contain solar flare tracks (pers. comm. John Bradley, McCrone Associates, Chicago). Almost all type I IDPs studied contain low-iron manganese enriched (LIME) olivines and/or pyroxenes.

scholarly journals Structural, chemical and isotopic examinations of interstellar organic matter extracted from meteorites and interstellar dust particles

2008 ◽  
Vol 4 (S251) ◽  
pp. 333-334
Author(s):  
Henner Busemann ◽  
Conel M. O'D. Alexander ◽  
Larry R. Nittler ◽  
Rhonda M. Stroud ◽  
Tom J. Zega ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solar System ◽  
Interstellar Dust ◽  
Focused Ion Beam ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Beam ◽  
Carbonaceous Material ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Interplanetary Dust Particles

AbstractMeteorites and Interplanetary Dust Particles (IDPs) are supposed to originate from asteroids and comets, sampling the most primitive bodies in the Solar System. They contain abundant carbonaceous material. Some of this, mostly insoluble organic matter (IOM), likely originated in the protosolar molecular cloud, based on spectral properties and H and N isotope characteristics. Together with cometary material returned with the Stardust mission, these samples provide a benchmark for models aiming to understand organic chemistry in the interstellar medium, as well as for mechanisms that secured the survival of these fragile molecules during Solar System formation. The carrier molecules of the isotope anomalies are largely unknown, although amorphous carbonaceous spheres, so-called nanoglobules, have been identified as carriers. We are using Secondary Ion Mass Spectrometry to identify isotopically anomalous material in meteoritic IOM and IDPs at a ~100-200 nm scale. Organics of most likely interstellar origin are then extracted with the Focused-Ion-Beam technique and prepared for synchrotron X-ray and Transmission Electron Microscopy. These experiments yield information on the character of the H- and N-bearing interstellar molecules: While the association of H and N isotope anomalies with nanoglobules could be confirmed, we have also identified amorphous, micron-sized monolithic grains. D-enrichments in meteoritic IOM appear not to be systematically associated with any specific functional groups, whereas 15N-rich material can be related to imine and nitrile functionality. The large 15N- enrichments observed here (δ15N > 1000 ‰) cannot be reconciled with models using interstellar ammonia ice reactions, and hence, provide new constraints for understanding the chemistry in cold interstellar clouds.

scholarly journals Laboratory Infrared Transmission Measurements of Interplanetary Dust and Implications for Remote Observations of Cosmic Particles

1985 ◽  
Vol 85 ◽  
pp. 273-273
Author(s):  
S.A. Sandford ◽  
R.M. Walker
Keyword(s):  
Laboratory Data ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Infrared Transmission ◽  
Interplanetary Dust Particles ◽  
Emission Data ◽  
Hydrated Silicate ◽  
Variable Position ◽  
Particle Spectra ◽  
Transmission Measurements

AbstractLaboratory infrared absorption spectra of interplanetary dust particles show that most fall into one of three spectral groups (1) designated as “pyroxenes”, “olivines”, and “hydrated silicates”.Comparisons with 10 μm emission data from Comet Kohoutek (2) show that no single spectral type matches the cometary data. However, a reasonable match is obtained by coadding equal amounts of pyroxene and hydrated silicate type spectra.The possibility that the 10 μm feature seen in some comets is due to a combination of these two components can be tested in two ways. First, the pyroxene type spectra show detailed features of variable position and strength within their 10 μm bands. Based on the laboratory data we estimate that comet spectra taken at a resolution of λ/Δλ ~ 200 would be sufficient to find these features, if present. The magnitude of these features is expected to be ≤ 0.1 of the maximum strength of the 10 μm band.Second, the hydrated silicate particles usually have bands at 3.0, 6.2, and 6.9 µm. The first two bands are probably linked to the presence of water while the 6.9 μm band is probably due to carbonates. The 3.0 μm feature is broad and might be hard to separate from thermal background. However, spectra taken at resolutions of λ/Δλ ~ 50 could see the 6.2 and 6.9 μm bands. The strengths of these bands (which are also seen in the spectra of CM meteorites) vary (one particle has a carbonate band that is actually stronger than its corresponding 10 μm silicate band), but are typically ~0.1 the depth of the silicate features. A second, narrow carbonate band at 11.4 μm can also sometimes be seen in particle spectra but its strength is less than that of the 6.9 μm band. This the search for the 6.2 and 6.9 μm bands in astronomical objects, while not requiring high resolutions, would require good S/N.

scholarly journals Cometary Silicates: Interstellar and Nebular Materials

2005 ◽  
Vol 13 ◽  
pp. 495-497 ◽  
Author(s):  
Diane H. Wooden
Keyword(s):  
Ir Spectra ◽  
Thermal Emission ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Interplanetary Dust Particles ◽  
Amorphous Silicate ◽  
Emission Models ◽  
Isotope Studies ◽  
Comet Halley

AbstractEvidence for interstellar material in comets is deduced from IR spectra, in situ measurements of Comet Halley, and chondritic porous interplanetary dust particles (CP IDPs). IR spectra of comets reveal the spectrally active minerals: amorphous carbon, amorphous silicates, and (in some comets) crystalline silicates. Evidence suggests amorphous silicates are of interstellar origin while crystalline silicates are of nebular origin.10 μm spectra of comets and sub-micron amorphous silicate spherules in CP IDPs have shapes similar to absorption spectra through lines-of-sight in the ISM. Thermal emission models of cometary IR spectra require Fe-bearing amorphous silicates. Fe-bearing amorphous silicates may be Fe-bearing crystalline silicates formed in AGB outflows that are amorphized through He+ ion bombardment in supernova shocks in the ISM.Crystalline silicates in comets, as revealed by IR spectra, and their apparent absence in the ISM, argues for their nebular origin. The high temperatures (>1000 K) at which crystals form or are annealed occur in the inner nebula or in nebular shocks in the 5 – 10 AU region. Oxygen isotope studies of CP IDPs show only 1% by mass of the silicate crystals are of AGB origin. Together this suggests crystalline silicates in comets are probably primitive grains from the early solar nebula.

scholarly journals Physical and Mineralogical Properties of Anhydrous Interplanetary Dust Particles in the Analytical Electron Microscope

1991 ◽  
Vol 126 ◽  
pp. 63-70
Author(s):  
J. P. Bradley
Keyword(s):  
Carbonaceous Material ◽  
Interplanetary Dust ◽  
Coarse Grained ◽  
Dust Particles ◽  
Interplanetary Dust Particles ◽  
Electron Microscopic ◽  
Atmospheric Entry ◽  
Fine Grained ◽  
Microscopic Studies ◽  
Solar Flare Tracks

AbstractThe fine grained mineralogy and petrography of anhydrous “pyroxene” and “olivine” classes of chondritic interplanetary dust have been investigated by numerous electron microscopic studies. The “pyroxene” interplanetary dust particles (IDPs) are porous, unequilibrated assemblages of mineral grains, metal, glass, and carbonaceous material. They contain enstatite whiskers, FeNi carbides, and high-Mn olivines and pyroxenes, all of which are likely to be well preserved products of nebular gas reactions. Solar flare tracks are prominent in most “pyroxene” IDPs, indicating that they were not strongly heated during atmospheric entry. The “olivine” IDPs are coarse grained, equilibrated mineral assemblages that have probably experienced strong heating. Since most “olivine” IDPs do not contain tracks, it is possible that this heating occurred during atmospheric entry.

IDENTIFICATION AND ANALYSIS OF INTERPLANETARY DUST PARTICLES FILTERED FROM ANTARCTIC AIR

2018 ◽  
Author(s):  
Katherine Burgess ◽  
◽  
David Bour ◽  
Rhonda M. Stroud ◽  
Anais Bardyn ◽  
...  
Keyword(s):  
Interplanetary Dust ◽  
Dust Particles ◽  
Interplanetary Dust Particles

scholarly journals On Two Mechanisms of X-Ray Generation in Comets

1985 ◽  
Vol 85 ◽  
pp. 365-368
Author(s):  
S. Ibadov
Keyword(s):  
High Temperature ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Interplanetary Dust Particles ◽  
Temperature Plasma ◽  
X Ray ◽  
Plasma Generation ◽  
High Temperature Plasma

AbstractThe intensity of solar X-radiation scattered by a comet is calculated and compared to the proper X-radiation of the comet due to impacts of cometary and interplanetary dust particles. Detection of X-radiation of dusty comets at small heliocentric distances (R ≤ 1 a.u.) is found to be an indicator of high-temperature plasma generation as result of grain collisions.

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