Nitrogen isotopic composition of macromolecular organic matter in interplanetary dust particles

AbstractInterplanetary dust particles (IDPs) collected in the Earths stratosphere derive from collisions among asteroids and by the disruption and outgassing of short-period comets. Chondritic porous (CP) IDPs are among the most primitive Solar System materials. CP-IDPs have been linked to cometary parent bodies by their mineralogy, textures, C-content, and dynamical histories. CP-IDPs are fragile, fine-grained (< um) assemblages of anhydrous amorphous and crystalline silicates, oxides and sulfides bound together by abundant carbonaceous material. Ancient silicate, oxide, and SiC stardust grains exhibiting highly anomalous isotopic compositions are abundant in CP-IDPs, constituting 0.01-1% of the mass of the particles. The organic matter in CP-IDPs is isotopically anomalous, with enrichments in D/H reaching 50x the terrestrial SMOW value and 15N/14N ratios up to 3x terrestrial standard compositions. These anomalies are indicative of low T (10-100 K) mass fractionation in cold molecular cloud or the outermost reaches of the protosolar disk. The organic matter shows distinct morphologies, including sub-um globules, bubbly textures, featureless, and with mineral inclusions. Infrared spectroscopy and mass spectrometry studies of organic matter in IDPs reveals diverse species including aliphatic and aromatic compounds. The organic matter with the highest isotopic anomalies appears to be richer in aliphatic compounds. These materials also bear similarities and differences with primitive, isotopically anomalous organic matter in carbonaceous chondrite meteorites. The diversity of the organic chemistry, morphology, and isotopic properties in IDPs and meteorites reflects variable preservation of interstellar/primordial components and Solar System processing. One unifying feature is the presence of sub-um isotopically anomalous organic globules among all primitive materials, including IDPs, meteorites, and comet Wild-2 samples returned by the Stardust mission. We will present an overview of the current state of understanding of the properties and origins of organic matter in primitive IDPs.

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Dome C ultracarbonaceous Antarctic micrometeorites

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731322 ◽

2018 ◽

Vol 609 ◽

pp. A65 ◽

Cited By ~ 20

Author(s):

E. Dartois ◽

C. Engrand ◽

J. Duprat ◽

M. Godard ◽

E. Charon ◽

...

Keyword(s):

Organic Matter ◽

Solar System ◽

Absorption Band ◽

Raman Spectra ◽

Interplanetary Dust ◽

Organic Component ◽

Dust Particles ◽

Interplanetary Dust Particles ◽

Lower Oxygen ◽

Carbonyl Absorption Band

Context. UltraCarbonaceous Antarctic MicroMeteorites (UCAMMs) represent a small fraction of interplanetary dust particles reaching the Earth’s surface and contain large amounts of an organic component not found elsewhere. They are most probably sampling a contribution from the outer regions of the solar system to the local interplanetary dust particle (IDP) flux. Aims. We characterize UCAMMs composition focusing on the organic matter, and compare the results to the insoluble organic matter (IOM) from primitive meteorites, IDPs, and the Earth. Methods. We acquired synchrotron infrared microspectroscopy (μFTIR) and μRaman spectra of eight UCAMMs from the Concordia/CSNSM collection, as well as N/C atomic ratios determined with an electron microprobe. Results. The spectra are dominated by an organic component with a low aliphatic CH versus aromatic C=C ratio, and a higher nitrogen fraction and lower oxygen fraction compared to carbonaceous chondrites and IDPs. The UCAMMs carbonyl absorption band is in agreement with a ketone or aldehyde functional group. Some of the IR and Raman spectra show a C≡N band corresponding to a nitrile. The absorption band profile from 1400 to 1100 cm-1 is compatible with the presence of C-N bondings in the carbonaceous network, and is spectrally different from that reported in meteorite IOM. We confirm that the silicate-to-carbon content in UCAMMs is well below that reported in IDPs and meteorites. Together with the high nitrogen abundance relative to carbon building the organic matter matrix, the most likely scenario for the formation of UCAMMs occurs via physicochemical mechanisms taking place in a cold nitrogen rich environment, like the surface of icy parent bodies in the outer solar system. The composition of UCAMMs provides an additional hint of the presence of a heliocentric positive gradient in the C/Si and N/C abundance ratios in the solar system protoplanetary disc evolution.

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A Raman spectroscopic study of organic matter in interplanetary dust particles and meteorites using multiple wavelength laser excitation

Meteoritics and Planetary Science ◽

10.1111/maps.12196 ◽

2013 ◽

Vol 48 (10) ◽

pp. 1800-1822 ◽

Cited By ~ 20

Author(s):

N. A. Starkey ◽

I. A. Franchi ◽

C. M. O'D. Alexander

Keyword(s):

Organic Matter ◽

Spectroscopic Study ◽

Laser Excitation ◽

Interplanetary Dust ◽

Dust Particles ◽

Interplanetary Dust Particles ◽

Raman Spectroscopic ◽

Raman Spectroscopic Study ◽

Multiple Wavelength

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Presolar grains in the Solar System: Connections to stellar and interstellar organics

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308021911 ◽

2008 ◽

Vol 4 (S251) ◽

pp. 343-344

Author(s):

Larry R. Nittler

Keyword(s):

Organic Matter ◽

Solar System ◽

Interplanetary Dust ◽

Asymptotic Giant Branch ◽

Dust Particles ◽

Interplanetary Dust Particles ◽

Molecular Chemistry ◽

Stellar Outflows ◽

Isotopic Compositions ◽

Polycyclic Aromatic

AbstractA small fraction of primitive meteorites and interplanetary dust particles (IDPs) consists of grains of presolar stardust. These grains have extremely unusual isotopic compositions, relative to all other planetary materials, indicating that they condensed in the outflows and explosions of prior generations of stars (Clayton & Nittler 2004). Identified presolar grain types include silicate, oxide and carbonaceous phases. The latter include graphitic carbon, diamond and SiC. Although many of these phases do not have a direct connection to organic chemistry, this is not true of the graphitic spherules. Many of these, with isotopic compositions indicating an origin in C-rich asymptotic giant branch (AGB) star outflows, have a structure consisting of naonocrystalline cores surrounded by well-graphitized C (Bernatowicz et al. 1996). The cores include isotopically anomalous polycyclic aromatic hydrocarbons (Messenger et al. 1998) and represent a link between molecular chemistry and dust condensation in stellar outflows. Meteorites and IDPs also contain abundant isotopically anomalous organic matter, including distinct organic grains, some of which probably formed in stellar outflows and/or the interstellar medium (ISM) (Busemann et al. 2006, Floss et al. 2004). In some IDPs, deuterium- and 15N-enriched organic matter is closely associated with presolar silicate grains (Messenger et al. 2005, Nguyen et al. 2007), suggesting an association in the ISM prior to Solar System formation.

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The origin of organic matter in the solar system: evidence from the interplanetary dust particles

Geochimica et Cosmochimica Acta ◽

10.1016/j.gca.2003.09.001 ◽

2003 ◽

Vol 67 (24) ◽

pp. 4791-4806 ◽

Cited By ~ 154

Author(s):

G.J Flynn ◽

L.P Keller ◽

M Feser ◽

S Wirick ◽

C Jacobsen

Keyword(s):

Organic Matter ◽

Solar System ◽

Interplanetary Dust ◽

Dust Particles ◽

Interplanetary Dust Particles

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The Origin of Organic Matter in the Solar System: Evidence from the Interplanetary Dust Particles

Symposium - International Astronomical Union ◽

10.1017/s0074180900193404 ◽

2004 ◽

Vol 213 ◽

pp. 275-280 ◽

Cited By ~ 1

Author(s):

G. J. Flynn ◽

L. P. Keller ◽

C. Jacobsen ◽

S. Wirick

Keyword(s):

Organic Matter ◽

Gas Phase ◽

Interplanetary Dust ◽

Dust Particles ◽

Aqueous Processing ◽

Interplanetary Dust Particles ◽

Volatile Elements ◽

Edge Structure ◽

X Ray ◽

X Ray Absorption

Interplanetary dust particles (IDPs), ∼ 10μm particles from comets and asteroids, have been collected by NASA from the Earth's stratosphere. We compared carbon X-ray Absorption Near-Edge Structure (XANES) and Fourier Transform Infra-Red (FTIR) spectra of anhydrous and hydrated interplanetary dust particles and found that anhydrous and hydrated IDPs have similar types and abundances of organic carbon. This is different from results on meteorites, which show that hydrated carbonaceous meteorites contain abundant organic matter, while anhydrous carbonaceous meteorites contain less carbon mostly in elemental form. But all anhydrous carbonaceous meteorites are depleted in moderately volatile and volatile elements in a pattern that suggested they experienced temperatures in excess of 1200°C, a temperature sufficient to destroy any organic matter they originally contained, while many anhydrous IDPs show no evidence of severe heating. These IDP results indicate that the bulk of the pre-biotic organic matter in extraterrestrial materials formed before aqueous processing, possibly by irradiation of C-bearing ices or by a Fisher-Tropsch type process operating in the gas phase of the nebula or in the interstellar medium.

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A Common Origin for Organics in Meteorites and Comets: Was It Interstellar?

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311025051 ◽

2011 ◽

Vol 7 (S280) ◽

pp. 288-301 ◽

Cited By ~ 8

Author(s):

Conel M. O'D. Alexander

Keyword(s):

Organic Matter ◽

Solar System ◽

Organic Material ◽

Protoplanetary Disks ◽

Interplanetary Dust ◽

Dust Particles ◽

Soluble Organic Matter ◽

Interplanetary Dust Particles ◽

Cold Environments ◽

Insoluble Material

AbstractThe insoluble organic material preserved in primitive chondritic meteorites shares many similarities with the refractory organic material in interplanetary dust particles and comets, suggesting that there is a genetic link between the organic matter in objects that formed between ~3 AU and ~30 AU from the Sun. These similarities include large D and 15N enrichments in bulk and even more extreme enrichments in isotopic hotspots. The enrichments attest to formation in very cold environments, either in the outer Solar System or the protosolar molecular cloud. There are many properties of this organic material that are consistent with an interstellar origin, but a Solar System origin cannot be ruled out. Similar organic material is presumably an important component of most protoplanetary disks, and heating or sputtering of this material would be a source of PAHs in disks. The soluble organic matter was more heavily effected by processes on the chondritic parent bodies than the insoluble material. Amino acids, for instance, probably formed by reaction of ketones and aldehydes with NH3 and HCN. The accretion of the relatively volatile NH3 and HCN, presumably in ices, strengthens the chondrite-comet connection. However, unlike most comets the water in chondrites, when it was accreted, had D/H ratios that were similar to or depleted relative to Earth.

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

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308021881 ◽

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.

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