WorldWideScience

Sample records for cm meteorite parent

  1. Enrichment of the Amino Acid L-Isovaline by Aqueous Alteration on CI and CM Meteorite Parent Bodies

    Science.gov (United States)

    Glavin, Daniel P.; Dworkin, Jason P.

    2009-01-01

    The distribution and enantiomeric composition of the 5-carbon (C(sub 5)) amino acids found in Cl-, CM-, and CR-type carbonaceous meteorites were investigated by using liquid chromatography fluorescence detection/TOF-MS coupled with o-phthaldialdehyde/Nacetyl- l-cysteine derivatization. A large L-enantiomeric excess (ee) of the a-methyl amino acid isovaline was found in the CM meteorite Murchison (L(sub ee) = 18.5 +/- 2.6%) and the Cl meteorite Orguell (L(sub ee) = 15.2 +/- 4.0%). The measured value for Murchison is the largest enantiomeric excess in any meteorite reported to date, and the Orgueil measurement of an isovaline excess has not been reported previously for this or any Cl meteorite. The L-isovaline enrichments in these two carbonaceous meteorites cannot be the result of interference from other C(sub 5) amino acid isomers present in the samples, analytical biases, or terrestrial amino acid contamination. We observed no L-isovaline enrichment for the most primitive unaltered Antarctic CR meteorites EET 92042 and QUE 99177. These results are inconsistent with UV circularly polarized light as the primary mechanism for L-isovaline enrichment and indicate that amplification of a small initial isovaline asymmetry in Murchison and Orgueil occurred during an extended aqueous alteration phase on the meteorite parent bodies. The large asymmetry in isovaline and other alpha-dialkyl amino acids found in altered Ct and CM meteorites suggests that amino acids delivered by asteroids, comets, and their fragments would have biased the Earth's prebiotic organic inventory with left-handed molecules before the origin of life.

  2. Coordinated Chemical and Isotopic Imaging of Bells (CM2) Meteorite Matrix

    Science.gov (United States)

    Clemett, S. J.; Messenger, S.; Naklamura-Messenger, K.; Thomas-Keprta, K. L.

    2014-01-01

    Meteoritic organic matter is a complex conglomeration of species formed in distinct environments and processes in circumstellar space, the interstellar medium, the Solar Nebula and asteroids. Consequently meteorites constitute a unique record of primordial organic chemical evolution. While bulk chemical analysis has provided a detailed description of the range and diversity of organic species present in carbonaceous chondrites, there is little information as to how these species are spatially distributed and their relationship to the host mineral matrix. The distribution of organic phases is nevertheless critical to understanding parent body processes. The CM and CI chondrites all display evidence of low temperature (chemical mapping study of the Bells meteorite using a newly developed two-step laser mass spectrometer (mu-L(sup 2)MS) capable of measuring a broad range of organic compounds.

  3. The Mukundpura meteorite, a new fall of CM chondrite

    Science.gov (United States)

    Ray, Dwijesh; Shukla, Anil D.

    2018-02-01

    Mukundpura is a new CM chondrite fell near Jaipur, Rajasthan, India on June 6, 2017 at 5:15 IST. The fall was observed by local villager. According to eyewitness, the meteorite was fragmented into several pieces once the object hit the ground. Based on petrography, mineralogy and bulk composition, Mukundpura is classified as CM2 chondrite. The chondrules are mainly similar to type I (Olivine: Fo99). Olivines are often found associated with pyroxene (Wo10-35En62-87Fs2-7) phenocryst. However, occurrences of forsteritic and fayalitic olivine (Fa58-71) as isolated mineral clast in matrix are not uncommon. Other types of chondrules include porphyritic pyroxene (En86Fs14) and barred olivine (Fa32.7±0.3) clast. Chondrules are commonly rimmed by fine-grained accretionary dust mantles. Phyllosilicates are the most dominant secondary mineral in matrix and largely associated with poorly characterised phases (PCP). FeO/SiO2 and S/SiO2 of PCP are 2.7 and 0.4 respectively. Other phases in matrix generally include calcite (pure CaCO3), Fe-Ni metal and sulphides. Spinel and perovskite occur occasionally as inclusions. The spherical or elliptical shaped metals (within chondrule or in isolated grains) are low-Ni type (kamacite <7.5 wt%) and resembles the solar Ni/Co ratio. However, Ni content in metal rarely exceeds 8.5 wt% (up to 23 wt%, taenite). Pyrrhotite (Fe ∼62 wt%; S ∼38 wt%) and pentlandite (Fe ∼31-33 wt%, Ni ∼28-32 wt%, S ∼33 wt%)) are the common sulphides occur as isolated grains within the matrix, however, the former is the most dominant. The bulk chemical composition of Mukundpura is largely similar to other CM type chondrite (e.g. Paris CM). Based on petrography, we infer a modest aqueous alteration stage for Mukundpura while the effect of thermal metamorphism was negligible.

  4. The amino acid and hydrocarbon contents of the Paris meteorite: Insights into the most primitive CM chondrite

    Science.gov (United States)

    Martins, Zita; Modica, Paola; Zanda, Brigitte; D'Hendecourt, Louis Le Sergeant

    2015-05-01

    The Paris meteorite is one of the most primitive carbonaceous chondrites. It is reported to be the least aqueously altered CM chondrite, and to have experienced only weak thermal metamorphism. We have analyzed for the first time the amino acid and hydrocarbon contents of this pristine meteorite by gas chromatography-mass spectrometry (GC-MS). When plotting the relative amino acids abundances of several CM chondrites according to the increasing hydrothermal scale (petrologic subtypes), from the CM2.7/2.8 Paris to the CM2.0 MET 01070, Paris has the lowest relative abundance of β-alanine/glycine (0.15), which fits with the relative abundances of β-alanine/glycine increasing with increasing aqueous alteration for CM chondrites. These results confirm the influence of aqueous alteration on the amino acid abundances and distribution. The amino acid analysis shows that the isovaline detected in this meteorite is racemic (D/L = 0.99 ± 0.08; L-enantiomer excess = 0.35 ± 0.5%; corrected D/L = 1.03; corrected L-enantiomer excess = -1.4 ± 2.6%). The identified hydrocarbons show that Paris has n-alkanes ranging from C16 to C25 and 3- to 5-ring nonalkylated polycyclic aromatic hydrocarbons (PAHs). The lack of alkylated PAHs in Paris seems to be also related to this low degree of aqueous alteration on its parent body. The extraterrestrial hydrocarbon content, suggested by the absence of any biomarker, may well have a presolar origin. The chemistry of the Paris meteorite may thus be closely related to the early stages of the solar nebula with a contribution from interstellar (molecular cloud) precursors.

  5. Meteoritic Amino Acids: Diversity in Compositions Reflects Parent Body Histories

    Science.gov (United States)

    Elsila, Jamie E.; Aponte, Jose C.; Blackmond, Donna G.; Burton, Aaron S.; Dworkin, Jason P.; Glavin, Daniel P.

    2016-01-01

    The analysis of amino acids in meteorites dates back over 50 years; however, it is only in recent years that research has expanded beyond investigations of a narrow set of meteorite groups (exemplied by the Murchison meteorite) into meteorites of other types and classes. These new studies have shown a wide diversity in the abundance and distribution of amino acids across carbonaceous chondrite groups, highlighting the role of parent body processes and composition in the creation, preservation, or alteration of amino acids. Although most chiral amino acids are racemic in meteorites, the enantiomeric distribution of some amino acids, particularly of the nonprotein amino acid isovaline, has also been shown to vary both within certain meteorites and across carbonaceous meteorite groups. Large -enantiomeric excesses of some extraterrestrial protein amino acids (up to 60) have also been observed in rare cases and point to nonbiological enantiomeric enrichment processes prior to the emergence of life. In this Outlook, we review these recent meteoritic analyses, focusing on variations in abundance, structural distributions, and enantiomeric distributions of amino acids and discussing possible explanations for these observations and the potential for future work.

  6. Parent Body Influences on Amino Acids in the Tagish Lake Meteorite

    Science.gov (United States)

    Glavin, D. P.; Callahan, M. P.; Dworkin, J. P.; Elsila, J. E.; Herd, C. D. K.

    2010-01-01

    The Tagish Lake meteorite is a primitive C2 carbonaceous chondrite with a mineralogy, oxygen isotope, and bulk chemical. However, in contrast to many CI and CM carbonaceous chondrites, the Tagish Lake meteorite was reported to have only trace levels of indigenous amino acids, with evidence for terrestrial L-amino acid contamination from the Tagish Lake meltwater. The lack of indigenous amino acids in Tagish Lake suggested that they were either destroyed during parent body alteration processes and/or the Tagish Lake meteorite originated on a chemically distinct parent body from CI and CM meteorites where formation of amino acids was less favorable. We recently measured the amino acid composition of three different lithologies (11h, 5b, and 11i) of pristine Tagish Lake meteorite fragments that represent a range of progressive aqueous alteration in order 11h amino acids found in hot-water extracts of the Tagish Lake fragments were determined by ultra performance liquid chromatography fluorescence detection and time of flight mass spectrometry coupled with OPA/NAC derivatization. Stable carbon isotope analyses of the most abundant amino acids in 11h were measured with gas chromatography coupled with quadrupole mass spectrometry and isotope ratio mass spectrometry.

  7. Chondritic Meteorites: Nebular and Parent-Body Formation Processes

    Science.gov (United States)

    Rubin, Alan E.; Lindstrom, David (Technical Monitor)

    2002-01-01

    It is important to identify features in chondrites that formed as a result of parent-body modification in order to disentangle nebular and asteroidal processes. However, this task is difficult because unmetamorphosed chondritic meteorites are mixtures of diverse components including various types of chondrules, chondrule fragments, refractory and mafic inclusions, metal-sulfide grains and fine-grained matrix material. Shocked chondrites can contain melt pockets, silicate-darkened material, metal veins, silicate melt veins, and impact-melt-rock clasts. This grant paid for several studies that went far in helping to distinguish primitive nebular features from those produced during asteroidal modification processes.

  8. Comets as parent bodies of CI1 carbonaceous meteorites and possible habitats of ice-microbes

    Science.gov (United States)

    Wickramasinghe, N. Chandra; Wickramasinghe, Janaki T.; Wallis, Jamie; Hoover, Richard B.; Rozanov, Alexei Y.

    2011-10-01

    Recent studies of comets and cometary dust have confirmed the presence of biologically relevant organic molecules along with clay minerals and water ice. It is also now well established by deuterium/hydrogen ratios that the CI1 carbonaceous meteorites contain indigenous extraterrestrial water. The evidence of extensive aqueous alteration of the minerals in these meteorites led to the hypothesis that water-bearing asteroids or comets represent the parent bodies of the CI1 (and perhaps CM2) carbonaceous meteorites. These meteorites have also been shown to possess a diverse array of complex organics and chiral and morphological biomarkers. Stable isotope studies by numerous independent investigators have conclusively established that the complex organics found in these meteorites are both indigenous and extraterrestrial in nature. Although the origin of these organics is still unknown, some researchers have suggested that they originated by unknown abiotic mechanisms and may have played a role in the delivery of chiral biomolecules and the origin of life on Early Earth. In this paper we review these results and investigate the thermal history of comets. We show that permanent as well as transient domains of liquid water can be maintained on a comet under a plausible set of assumptions. With each perihelion passage of a comet volatiles are preferentially released, and during millions of such passages the comet could shed crustal debris that may survive transit through the Earth's atmosphere as a carbonaceous meteorite. We review the current state of knowledge of comets and carbonaceous meteorites. We also present the results of recent studies on the long-term viability of terrestrial ice-microbiota encased in ancient glacial ice and permafrost. We suggest that the conditions which have been observed to prevail on many comets do not preclude either survivability (or even the active metabolism and growth) of many types of eukaryotic and prokaryotic microbial

  9. Comets as Parent Bodies of CI1 Carbonaceous Meteorites and Possible Habitats of Ice-Microbiota

    Science.gov (United States)

    Wickramasinghe, N. Chandra; Wallis, Daryl H.; Rozanov, Alexei Yu.; Hoover, Richard B.

    2011-01-01

    Recent studies of comets and cometary dust have confirmed the presence of biologically relevant organic molecules along with clay minerals and water ice. It is also now well established by deuterium/hydrogen ratios that the CI1 carbonaceous meteorites contain indigenous extraterrestrial water. The evidence of extensive aqueous alteration of the minerals in these meteorites led to the hypothesis that water-bearing asteroids or comets represent the parent bodies of the CI1 (and perhaps CM2) carbonaceous meteorites. These meteorites have also been shown to possess a diverse array of complex organics and chiral and morphological biomarkers. Stable isotope studies by numerous independent investigators have conclusively established that the complex organics found in these meteorites are both indigenous and extraterrestrial in nature. Although the origin of these organics is still unknown, some researchers have suggested that they originated by unknown abiotic mechanisms and may have played a role in the delivery of chiral biomolecules and the origin of life on Early Earth. In this paper we review these results and investigate the thermal history of comets. We show that permanent as well as transient domains of liquid water can be maintained on a comet under a plausible set of assumptions. With each perihelion passage of a comet volatiles are preferentially released, and during millions of such passages the comet could shed crustal debris that may survive transit through the Earth s atmosphere as a carbonaceous meteorite. We review the current state of knowledge of comets and carbonaceous meteorites. We also present the results of recent studies on the long-term viability of terrestrial ice-microbiota encased in ancient glacial ice and permafrost. We suggest that the conditions which have been observed to prevail on many comets do not preclude either survivability (or even the active metabolism and growth) of many types of eukaryotic and prokaryotic microbial

  10. Tochilinite: A Sensitive Indicator of Alteration Conditions on the CM Asteroidal Parent Body

    Science.gov (United States)

    Browning, L. B.; Bourcier, W. L.

    1996-03-01

    Each CM chondrite experienced a different degree of aqueous alteration. As a group, then, these meteorites preserve tangible evidence of asteroidal reactions that were interrupted at many different stages of completion. Geochemical modeling of CM reaction progress should elucidate the nature of the accreted CM materials and the specific types of asteroidal processes and conditions that subsequently influenced them. However, most of the minerals in CM chondrites are stable under a wide range of environmental conditions, which hinders efforts to capitalize on the diverse degree of CM alteration. Petrologic evidence suggests that Fe-rich tochilinite, the widespread mineralic component of CM chondrites previously referred to as "poorly characterized phase (PCP)", may be the most sensitive indicator of the conditions of CM alteration. This possibility has not previously been explored because thermodynamic data for tochilinite are lacking. We have estimated the thermodynamic properties of tochilinite from mixing equations and then calculated its stability limits with associated non-silicate phases as a function of PS2, PO2, and PCO2. The resultant phase relations : a) are consistent with mineral association in CM chondrites, b) indicate that the CM fluids were S-depleted and extremely reducing, c) imply the possibility of H2 gas seeps on the CM parent body, and d) suggest that the alteration of CM materials occurred at significant asteroidal depths.

  11. Nature and evolution of the meteorite parent bodies: Evidence from petrology and metallurgy

    Science.gov (United States)

    Wood, J. A.

    1978-01-01

    The physical as well as chemical properties of the meteorite parent bodies are reviewed and it is concluded that many differentiated meteorites were likely formed in asteroidal-sized parents. A new model is developed for the formation of pallasites at the interface between an iron core and olivine mantle in differentiated bodies only about 10 km in diameter, which are later incorporated into a second generation of larger (100 km) parent bodies.

  12. On possible parent bodies of Innisfree, Lost City and Prgibram meteorites.

    Science.gov (United States)

    Rozaev, A. E.

    1994-12-01

    Minor planets 1981 ET3 and Seleucus are possible parent bodies of Innisfree and Lost City meteorites, asteroid Mithra is the most probable source of Prgibram meteorite. The conclusions are based on the Southworth - Hawkins criterion with taking into account of the motion constants (Tisserand coefficient, etc.) and minimal distances between orbits at present time.

  13. Water Transport and the Evolution of CM Parent Bodies

    Science.gov (United States)

    Coker, Rob; Cohen, Barbara

    2014-01-01

    Meteorites have amino acids and hydrated minerals which constrain the peak temperature ranges they have experienced. CMs in particular have a narrow range (273-325K). Bulk fluid motion during hydration constrained to small scales (less than mm). Some asteroids are known to have hydrated minerals on their surfaces. It is presumed these two facts may be related. Problem: hydration only occurs (significantly) with liquid water; melting water only occurs early on in nebula (1-10 Myrs ANC); in nebula asteroid surface temperature very cold (approximately 150K). Can indigenous alteration produce CMs and/or surface hydration?

  14. Mineralogy, Petrology, Chronology, and Exposure History of the Chelyabinsk Meteorite and Parent Body

    Science.gov (United States)

    Righter, K.; Abell, P.; Agresti, D.; Berger, E. L.; Burton, A. S.; Delaney, J. S.; Fries, M. D.; Gibson, E. K.; Harrington, R.; Herzog, G. F.; hide

    2015-01-01

    The Chelyabinsk meteorite fall on February 15, 2013 attracted much more attention worldwide than do most falls. A consortium led by JSC received 3 masses of Chelyabinsk (Chel-101, -102, -103) that were collected shortly after the fall and handled with care to minimize contamination. Initial studies were reported in 2013; we have studied these samples with a wide range of analytical techniques to better understand the mineralogy, petrology, chronology and exposure history of the Chelyabinsk parent body.

  15. The parent magma of the nakhlite meteorites - Clues from melt inclusions

    Science.gov (United States)

    Harvey, Ralph P.; Mcsween, Harry Y., Jr.

    1992-01-01

    Several forms of trapped liquid found within nakhlite meteorites have been examined, including interstitial melt and magmatic inclusions within the cores of large olivine grains. Differences in the mineralogy and texture between two types of trapped melt inclusions, and between these inclusions and the mesostasis, indicate that vitrophyric inclusions are most appropriate for estimating the composition of a nakhlite parental magma in equilibrium with early-forming olivine and augite. Parent liquids were calculated from the mineralogy of large inclusions in Nakhla and Governador Valadares, using a system of mass-balance equations solved by linear regression methods. The chosen parental liquids were cosaturated in olivine and augite and had Mg/Fe values consistent with measured augite/liquid Kds. These parental magma compositions are similar to other published compositions for Nakhla, Chassigny, and Shergotty parental melts, and may correspond to a significant magma type on Mars.

  16. Meteoritic basalts: the nakhlites, their parental magmas, cooling rates, and equivalents on Earth. Final technical report

    International Nuclear Information System (INIS)

    Treiman, A.H.

    1987-07-01

    Proposed one-bar phase equilibrium experiments, designed to determine the compositions of the nakhlites' parental magmas, are in progress. Proposed field studies on Earth, designed to find occurrences of rocks like the nakhlites, were extraordinarily successful. Other work supported in the past year included: attendance at the 1986 national meeting of the Geological Society of America; attendance at the 18th Lunar and Planetary Science Conference; completion and publication of a study of core formation in the SNC parent body; initiation of a study of the flux of SNC meteorites onto the Earth; and initiation of petrologic study of the Angra dos Reis achondrite

  17. Spectral evidence for amorphous silicates in least-processed CO meteorites and their parent bodies

    Science.gov (United States)

    McAdam, Margaret M.; Sunshine, Jessica M.; Howard, Kieren T.; Alexander, Conel M.; McCoy, Timothy J.; Bus, Schelte J.

    2018-05-01

    Least-processed carbonaceous chondrites (carbonaceous chondrites that have experienced minimal aqueous alteration and thermal metamorphism) are characterized by their predominately amorphous iron-rich silicate interchondrule matrices and chondrule rims. This material is highly susceptible to destruction by the parent body processes of thermal metamorphism or aqueous alteration. The presence of abundant amorphous material in a meteorite indicates that the parent body, or at least a region of the parent body, experienced minimal processing since the time of accretion. The CO chemical group of carbonaceous chondrites has a significant number of these least-processed samples. We present visible/near-infrared and mid-infrared spectra of eight least-processed CO meteorites (petrologic type 3.0-3.1). In the visible/near-infrared, these COs are characterized by a broad weak feature that was first observed by Cloutis et al. (2012) to be at 1.3-μm and attributed to iron-rich amorphous silicate matrix materials. This feature is observed to be centered at 1.4-μm for terrestrially unweathered, least-processed CO meteorites. At mid-infrared wavelengths, a 21-μm feature, consistent with Si-O vibrations of amorphous materials and glasses, is also present. The spectral features of iron-rich amorphous silicate matrix are absent in both the near- and mid-infrared spectra of higher metamorphic grade COs because this material has recrystallized as crystalline olivine. Furthermore, spectra of least-processed primitive meteorites from other chemical groups (CRs, MET 00426 and QUE 99177, and C2-ungrouped Acfer 094), also exhibit a 21-μm feature. Thus, we conclude that the 1.4- and 21-μm features are characteristic of primitive least-processed meteorites from all chemical groups of carbonaceous chondrites. Finally, we present an IRTF + SPeX observation of asteroid (93) Minerva that has spectral similarities in the visible/near-infrared to the least-processed CO carbonaceous chondrites

  18. Organic matter in primitive meteorites: a study of the hydrogen isotopic distribution in CM-type carbonaceous chondrites

    Science.gov (United States)

    Piani, L.; Yurimoto, H.; Remusat, L.; Gonzales, A.; Marty, B.

    2017-12-01

    Chondrite meteorites are fragments of rocks coming from small bodies of the asteroid belt and constitute witnesses of the volatile-rich reservoirs present in the inner protoplanetary disk. Among these meteorites, carbonaceous chondrites contain the largest quantity of water and organic matter and are one of the most probable candidates for the delivery of water and molecular origin of life to Earth. Organic matter in carbonaceous chondrites is intimately mixed with hydrated minerals challenging its in situ characterization and the determination of its H-isotope composition (Le Guillou et al., GCA 131, 2014). Organic matter occurs as soluble components (in water or organic solvents) and an insoluble macromolecule. The insoluble organic matter (IOM) is efficiently isolated after acid leaching of the chondrite minerals. IOM has thus been investigated by a large set of analytical techniques allowing its structural organization, chemical composition and isotopic composition to be determined at several scales (e.g. Derenne and Robert, MAPS 45, 2010). In the soluble counterpart (SOM), targeted studies have shown large ranges of D/H ratios in the different classes of soluble organic compounds (i.e. carboxylic acids, ketones and aldehydes, amino-acids etc.) (Remusat, Planetary Mineralogy 15, 2015 and references therein). This D/H distribution indicates a complex and probably multiple-stage synthesis of this organic compounds occurring at different stages of the disk evolution. Nevertheless, inventories of the known C-bearing species in carbonaceous chondrites (carbonates, SOM and IOM) show that about 40-50 % of the carbon is hidden within the matrix (Alexander et al., MAPS 50, 2015). In this study, we perform in situ hydrogen isotope analyses at the micrometer scale by secondary ion mass spectrometry to investigate the distribution of organic matter in primitive chondrites without the use of any chemical treatment. Correlated analyses of the D/H and C/H ratios allow us to

  19. Kinetics of organic matter degradation in the Murchison meteorite for the evaluation of parent-body temperature history

    Science.gov (United States)

    Kebukawa, Yoko; Nakashima, Satoru; Zolensky, Michael E.

    2010-01-01

    To evaluate kinetic parameters for thermal degradation of organic matter, in situ heating experiments of insoluble organic matter (IOM) and bulk of Murchison (CM2) meteorite were conducted under Fourier transform infrared micro-spectroscopy combined with a heating stage. Decreases of aliphatic C-H band area under Ar flow were well fitted with Ginstling-Brounshtein three-dimensional diffusion model, and the rate constants for decreases of aliphatic C-H were determined. Activation energies Ea and frequency factors A obtained from these rate constants at different temperatures using the Arrhenius equation were Ea=109+/-3kJmol-1 and A=8.7×104s-1 for IOM, and Ea=61+/-6kJmol-1 and A=3.8s-1 for bulk, respectively. Activation energy values of aliphatic C-H decrease are larger for IOM than bulk. Hence, the mineral assemblage of the Murchison meteorite might have catalytic effects for the organic matter degradation. Using obtained kinetic expressions, the time scale for metamorphism can be estimated for a given temperature with aliphatic C-H band area, or the temperature of metamorphism can be estimated for a given time scale. For example, using the obtained kinetic parameters of IOM, aliphatic C-H is lost approximately within 200years at 100°C and 100Myr at 0°C. Assuming alteration period of 7.5Myr, alteration temperatures could be calculated to be <15+/-12°C. Aliphatic C-H decrease profiles in a parent body can be estimated using time-temperature history model. The kinetic expression obtained by the infrared spectral band of aliphatic C-H could be used as an alternative method to evaluate thermal processes of organic matter in carbonaceous chondrites.

  20. The parent magma of the Nakhla (SNC) meteorite: Reconciliation of composition estimates from magmatic inclusions and element partitioning

    Science.gov (United States)

    Treiman, A. H.

    1993-01-01

    The composition of the parent magma of the Nakhla meteorite was difficult to determine, because it is accumulate rock, enriched in olivine and augite relative to a basalt magma. A parent magma composition is estimated from electron microprobe area analyses of magmatic inclusions in olivine. This composition is consistent with an independent estimate based on the same inclusions, and with chemical equilibria with the cores of Nakhla's augites. This composition reconciles most of the previous estimates of Nakhla's magma composition, and obviates the need for complex magmatic processes. Inconsistency between this composition and those calculated previously suggests that magma flowed through and crystallized into Nakhla as it cooled.

  1. CM and CO chondrites: A common parent body or asteroidal neighbors? Insights from chondrule silicates

    Science.gov (United States)

    Schrader, Devin L.; Davidson, Jemma

    2017-10-01

    By investigating the petrology and chemical composition of type II (FeO-rich) chondrules in the Mighei-like carbonaceous (CM) chondrites we constrain their thermal histories and relationship to the Ornans-like carbonaceous (CO) chondrites. We identified FeO-rich relict grains in type II chondrules by their Fe/Mn ratios; their presence indicates chondrule recycling among type II chondrules. The majority of relict grains in type II chondrules are FeO-poor olivine grains. Consistent with previous studies, chemical similarities between CM and CO chondrite chondrules indicate that they had similar formation conditions and that their parent bodies probably formed in a common region within the protoplanetary disk. However, important differences such as mean chondrule size and the lower abundance of FeO-poor relicts in CM chondrite type II chondrules than in CO chondrites suggest CM and CO chondrules did not form together and they likely originate from distinct parent asteroids. Despite being aqueously altered, many CM chondrites contain pre-accretionary anhydrous minerals (i.e., olivine) that are among the least thermally metamorphosed materials in chondrites according to the Cr2O3 content of their ferroan olivine. The presence of these minimally altered pre-accretionary chondrule silicates suggests that samples to be returned from aqueously altered asteroids by the Hayabusa2 and OSIRIS-REx asteroid sample return missions, even highly hydrated, may contain silicates that can provide information about the pre-accretionary histories and conditions of asteroids Ryugu and Bennu, respectively.

  2. Extraterrestrial Organic Compounds in Meteorites

    Science.gov (United States)

    Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

    2003-01-01

    Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

  3. Petrologic evolution of CM chondrites: The difficulty of discriminating between nebular and parent-body effects

    Science.gov (United States)

    Kerridge, J. F.; McSween, H. Y., Jr.; Bunch, T. E.

    1994-07-01

    We wish to draw attention to a major controversy that has arisen in the area of CM-chondrite petrology. The problem is important because its resolution will have profound implications for ideas concerning nebular dynamics, gas-solid interactions in the nebula, and accretionary processes in the nebula, among other issues. On the one hand, cogent arguments have been presented that 'accretionary dust mantles,' were formed in the solar nebula prior to accretion of the CM parent asteroid(s). On the other hand, no-less-powerful arguments have been advanced that a significant fraction of the CM lithology is secondary, produced by aqueous alteration in the near-surface regions of an asteroid-sized object. Because most, if not all, CM chondrites are breccias, these two views could coexist harmoniously, were it not for the fact that some of the coarse-grained lithologies surrounded by 'accretion dust mantles' are themselves of apparently secondary origin. Such an observation must clearly force a reassessment of one or both of the present schools of thought. Our objective here is to stimulate such a reassessment. Four possible resolutions of this conflict may be postulated. First, perhaps nature found a way of permitting such secondary alteration to take place in the nebula. Second, maybe dust mantles could form in a regolith, rather than a nebular, environment. Third, it is possible that dust mantles around secondary lithologies are different from those around primary lithologies. Finally, perhaps formation of CM chondrites involved a more complex sequence of events than visualized so far, so that some apparently 'primary' processes postdated certain 'secondary' processes.

  4. Fe isotope composition of bulk chondrules from Murchison (CM2): Constraints for parent body alteration, nebula processes and chondrule-matrix complementarity

    Science.gov (United States)

    Hezel, Dominik C.; Wilden, Johanna S.; Becker, Daniel; Steinbach, Sonja; Wombacher, Frank; Harak, Markus

    2018-05-01

    Chondrules are a major constituent of primitive meteorites. The formation of chondrules is one of the most elusive problems in cosmochemistry. We use Fe isotope compositions of chondrules and bulk chondrites to constrain the conditions of chondrule formation. Iron isotope compositions of bulk chondrules are so far only known from few studies on CV and some ordinary chondrites. We studied 37 chondrules from the CM chondrite Murchison. This is particularly challenging, as CM chondrites contain the smallest chondrules of all chondrite groups, except for CH chondrites. Bulk chondrules have δ56Fe between -0.62 and +0.24‰ relative to the IRMM-014 standard. Bulk Murchison has as all chondrites a δ56Fe of 0.00‰ within error. The δ56Fe distribution of the Murchison chondrule population is continuous and close to normal. The width of the δ56Fe distribution is narrower than that of the Allende chondrule population. Opaque modal abundances in Murchison chondrules is in about 67% of the chondrules close to 0 vol.%, and in 33% typically up to 6.5 vol.%. Chondrule Al/Mg and Fe/Mg ratios are sub-chondritic, while bulk Murchison has chondritic ratios. We suggest that the variable bulk chondrule Fe isotope compositions were established during evaporation and recondensation prior to accretion in the Murchison parent body. This range in isotope composition was likely reduced during aqueous alteration on the parent body. Murchison has a chondritic Fe isotope composition and a number of chondritic element ratios. Chondrules, however, have variable Fe isotope compositions and chondrules and matrix have complementary Al/Mg and Fe/Mg ratios. In combination, this supports the idea that chondrules and matrix formed from a single reservoir and were then accreted in the parent body. The formation in a single region also explains the compositional distribution of the chondrule population in Murchison.

  5. A Parent Magma for the Nakhla Martian Meteorite: Reconciliation of Estimates from 1-Bar Experiments, Magmatic Inclusions in Olivine, and Magmatic Inclusions in Augite

    Science.gov (United States)

    Treiman, Allan H.; Goodrich, Cyrena Anne

    2001-01-01

    The composition of the parent magma for the Nakhla (martian) meteorite has been estimated from mineral-melt partitioning and from magmatic inclusions in olivine and in augite. These independent lines of evidence have converged on small range of likely compositions. Additional information is contained in the original extended abstract.

  6. Asteroid/meteorite streams

    Science.gov (United States)

    Drummond, J.

    The independent discovery of the same three streams (named alpha, beta, and gamma) among 139 Earth approaching asteroids and among 89 meteorite producing fireballs presents the possibility of matching specific meteorites to specific asteroids, or at least to asteroids in the same stream and, therefore, presumably of the same composition. Although perhaps of limited practical value, the three meteorites with known orbits are all ordinary chondrites. To identify, in general, the taxonomic type of the parent asteroid, however, would be of great scientific interest since these most abundant meteorite types cannot be unambiguously spectrally matched to an asteroid type. The H5 Pribram meteorite and asteroid 4486 (unclassified) are not part of a stream, but travel in fairly similar orbits. The LL5 Innisfree meteorite is orbitally similar to asteroid 1989DA (unclassified), and both are members of a fourth stream (delta) defined by five meteorite-dropping fireballs and this one asteroid. The H5 Lost City meteorite is orbitally similar to 1980AA (S type), which is a member of stream gamma defined by four asteroids and four fireballs. Another asteroid in this stream is classified as an S type, another is QU, and the fourth is unclassified. This stream suggests that ordinary chondrites should be associated with S (and/or Q) asteroids. Two of the known four V type asteroids belong to another stream, beta, defined by five asteroids and four meteorite-dropping (but unrecovered) fireballs, making it the most probable source of the eucrites. The final stream, alpha, defined by five asteroids and three fireballs is of unknown composition since no meteorites have been recovered and only one asteroid has an ambiguous classification of QRS. If this stream, or any other as yet undiscovered ones, were found to be composed of a more practical material (e.g., water or metalrich), then recovery of the associated meteorites would provide an opportunity for in-hand analysis of a potential

  7. Nature's starships. I. Observed abundances and relative frequencies of amino acids in meteorites

    International Nuclear Information System (INIS)

    Cobb, Alyssa K.; Pudritz, Ralph E.

    2014-01-01

    The class of meteorites called carbonaceous chondrites are examples of material from the solar system which have been relatively unchanged from the time of their initial formation. These meteorites have been classified according to the temperatures and physical conditions of their parent planetesimals. We collate available data on amino acid abundance in these meteorites and plot the concentrations of different amino acids for each meteorite within various meteorite subclasses. We plot average concentrations for various amino acids across meteorites separated by subclass and petrologic type. We see a predominance in the abundance and variety of amino acids in CM2 and CR2 meteorites. The range in temperature corresponding to these subclasses indicates high degrees of aqueous alteration, suggesting aqueous synthesis of amino acids. Within the CM2 and CR2 subclasses, we identify trends in relative frequencies of amino acids to investigate how common amino acids are as a function of their chemical complexity. These two trends (total abundance and relative frequencies) can be used to constrain formation parameters of amino acids within planetesimals. Our organization of the data supports an onion shell model for the temperature structure of planetesimals. The least altered meteorites (type 3) and their amino acids originated near cooler surface regions. The most active amino acid synthesis likely took place at intermediate depths (type 2). The most altered materials (type 1) originated furthest toward parent body cores. This region is likely too hot to either favor amino acid synthesis or for amino acids to be retained after synthesis.

  8. Cosmic history and a candidate parent asteroid for the quasicrystal-bearing meteorite Khatyrka

    Science.gov (United States)

    Meier, Matthias M. M.; Bindi, Luca; Heck, Philipp R.; Neander, April I.; Spring, Nicole H.; Riebe, My E. I.; Maden, Colin; Baur, Heinrich; Steinhardt, Paul J.; Wieler, Rainer; Busemann, Henner

    2018-05-01

    The unique CV-type meteorite Khatyrka is the only natural sample in which "quasicrystals" and associated crystalline Cu, Al-alloys, including khatyrkite and cupalite, have been found. They are suspected to have formed in the early Solar System. To better understand the origin of these exotic phases, and the relationship of Khatyrka to other CV chondrites, we have measured He and Ne in six individual, ∼40-μm-sized olivine grains from Khatyrka. We find a cosmic-ray exposure age of about 2-4 Ma (if the meteoroid was family), and its location close to strong orbital resonances, so that the Khatyrka meteoroid could plausibly have reached Earth within its rather short cosmic-ray exposure age.

  9. Evidence favoring an internally generated dynamo in the H chondrite parent planetesimal from the Forest Vale meteorite

    Science.gov (United States)

    Getzin, B. L.; Bryson, J. F. J.; Weiss, B. P.; Gattacceca, J.

    2016-12-01

    Chondritic meteorites are traditionally assumed to originate from undifferentiated asteroids due to their unmelted texture and composition. This implies that their parent bodies should not have formed a core or generated a dynamo. However, recent measurements of the H chondrite Portales Valley (Bryson et al., this meeting) observed post-accretional remanent magnetization interpreted as a record of a core dynamo, indicating that some chondrite parent bodies were partially differentiated. However, it has been proposed that the H chondrites may have been magnetized instead by a crustal remanent field. If this crustal magnetization was imparted by an early external source, such as nebular fields or even the solar wind, then the magnetization of H chondrites may not require a core dynamo. To test this hypothesis, we measured the magnetic properties of the Forest Vale H4 ordinary chondrite. Forest Vale cooled quickly (10000 K/My) and so would have acquired magnetization that represents the bulk of the H chondrite parent body's crust during the first 10 My of the solar system. Based on alternating field and pressure demagnetization experiments of natural remanent magnetization (NRM) and anhysteretic remanent magnetization, we conclude that Forest Vale contains no ancient magnetization and, due to its poor intrinsic magnetic recording properties, is unable to acquire a magnetization that is stable against even weak shocks (0.2 GPa). Furthermore, we show that a crust composed of Forest-Vale-like material magnetized by the upper limit field intensities expected for the nebula and solar wind fields (50 μT and 1 μT, respectively) produces an insufficient crustal remanent field (<2.5 μT and <0.045 μT, respectively) to explain the paleointensity recorded by Portales Valley ( 10 μT). Thus, we conclude that the field that magnetization Portales Valley is unlikely to be from a crustal remanence magnetized by early external fields, favoring a partially differentiated asteroid

  10. Differentiation history of small bodies in the solar system: the howardite and mesosiderite meteorite parent bodies

    International Nuclear Information System (INIS)

    Mittlefehldt, D.W.

    1978-01-01

    Mesosiderites and howardites are regolith samples of differentiated asteroids. Instrumental neutron activation analysis (INAA) data on whole rock howardites and mesosiderite silicates show that the composition of howardites and mesosiderites are similar, and intermediate between those of eucrites and diogenites. The mesosiderites Mincy, Lowicz and Veramin show an enrichment in light REE and have an REE pattern that is qualitatively similar to that in terrestrial basalts thought to have been formed by small degrees of partial melting. Attempts to model the REE abundances in these mesosiderites indicates that they most likely formed by approx. 2 to 4% partial melting of a source containing low abundances of the rare earths. Since numerous properties separate mesosiderite silicates from howardites, it is clear that they are not samples of a well-mixed regolith from a single parent body. If regolith stirring is efficient on small parent bodies, then mesosiderites and howardites originated on separate parent bodies. Rare earth element patterns give evidence for remelting and fractional crystallization of preexisting cumulates and sequential melting episodes. The mesosiderites appear to contain a slightly greater abundance of diogenite-like material and certainly contain a greater abundance of large olivine clasts. These observations suggest that the mesosiderite parent body crust was more complexly fractionated than the howardite parent body crust. The latter appears to have been dominated by quenched basalt flows

  11. Stable isotope genealogy of meteorites

    International Nuclear Information System (INIS)

    Pillinger, C.T.

    1988-01-01

    One of the oldest problems in meteoritics is that of taxonomically grouping samples. In recent years the use of isotopes, particularly oxygen isotopes has proved very successful in this respect. Other light-element systematics potentially can perform the same function. For example, nitrogen in iron meteorites, and nitrogen and carbon in ureilites and SNC meteorites. These measurements will serve to extend and augment existing classification schemes and provide clues to the nature of meteorite parent bodies. They can also aid in the recognition of the isotopic signatures relating to inaccessible regions of the Earth. (author)

  12. Comets, Carbonaceous Meteorites, and the Origin of the Biosphere

    Science.gov (United States)

    Hoover, Richard B.

    2007-01-01

    Evidence for indigenous microfossils in carbonaceous meteorites suggests that the paradigm of the endogenous origin of life on Earth should be reconsidered. It is now widely accepted that comets and carbonaceous meteorites played an important role in the delivery of water, organics and life critical biogenic elements to the early Earth and facilitated the origin and evolution of the Earth's Biosphere. However; the detection of embedded microfossils and mats in carbonaceous meteorites implies that comets and meteorites may have played a direct role in the delivery of intact microorganisms and that the Biosphere may extend far into the Cosmos. Recent space observations have found the nuclei of comets to have very low albedos (approx.0.03) and. these jet-black surfaces become very hot (T approx. 400 K) near perihelion. This paper reviews recent observational data-on comets and suggests that liquid water pools could exist in cavities and fissures between the internal ices and rocks and the exterior carbonaceous crust. The presence of light and liquid water near the surface of the nucleus enhances the possibility that comets could harbor prokaryotic extremophiles (e.g., cyanobacteria) capable of growth over a wide range of temperatures. The hypothesis that comets are the parent bodies of the CI1 and the CM2 carbonaceous meteorites is advanced. Electron microscopy images will be presented showing forms interpreted as indigenous-microfossils embedded' in freshly. fractured interior surfaces of the Orgueil (CI1) and Murchison (CM2) meteorites. These forms are consistent in size and morphologies with known morphotypes of all five orders of Cyanobacteriaceae: Energy Dispersive X-ray Spectroscopy (EDS) elemental data shows that the meteoritic forms have anomalous C/O; C/N; and C/S as compared with modern extremophiles and cyanobacteria. These images and spectral data indicate that the clearly biogenic and embedded remains cannot be interpreted as recent biological

  13. Organic Molecules in Meteorites

    Science.gov (United States)

    Martins, Zita

    2015-08-01

    Carbonaceous meteorites are primitive samples from the asteroid belt, containing 3-5wt% organic carbon. The exogenous delivery of organic matter by carbonaceous meteorites may have contributed to the organic inventory of the early Earth. The majority (>70%) of the meteoritic organic material consist of insoluble organic matter (IOM) [1]. The remaining meteoritic organic material (meteorites contain soluble organic molecules with different abundances and distributions, which may reflect the extension of aqueous alteration or thermal metamorphism on the meteorite parent bodies. Extensive aqueous alteration on the meteorite parent body may result on 1) the decomposition of α-amino acids [5, 6]; 2) synthesis of β- and γ-amino acids [2, 6-9]; 3) higher relative abundances of alkylated polycyclic aromatic hydrocarbons (PAHs) [6, 10]; and 4) higher L-enantiomer excess (Lee) value of isovaline [6, 11, 12].The soluble organic content of carbonaceous meteorites may also have a contribution from Fischer-Tropsch/Haber-Bosch type gas-grain reactions after the meteorite parent body cooled to lower temperatures [13, 14].The analysis of the abundances and distribution of the organic molecules present in meteorites helps to determine the physical and chemical conditions of the early solar system, and the prebiotic organic compounds available on the early Earth.[1] Cody and Alexander (2005) GCA 69, 1085. [2] Cronin and Chang (1993) in: The Chemistry of Life’s Origin. pp. 209-258. [3] Martins and Sephton (2009) in: Amino acids, peptides and proteins in organic chemistry. pp. 1-42. [4] Martins (2011) Elements 7, 35. [5] Botta et al. (2007) MAPS 42, 81. [6] Martins et al. (2015) MAPS, in press. [7] Cooper and Cronin (1995) GCA 59, 1003. [8] Glavin et al. (2006) MAPS. 41, 889. [9] Glavin et al. (2011) MAPS 45, 1948. [10] Elsila et al. (2005) GCA 5, 1349. [11] Glavin and Dworkin (2009) PNAS 106, 5487. [12] Pizzarello et al. (2003) GCA 67, 1589. [13] Chan et al. (2012) MAPS. 47, 1502

  14. Organic Chemistry of Meteorites

    Science.gov (United States)

    Chang, S.; Morrison, David (Technical Monitor)

    1994-01-01

    Studies of the molecular structures and C,N,H-isotopic compositions of organic matter in meteorites reveal a complex history beginning in the parent interstellar cloud which spawned the solar system. Incorporation of interstellar dust and gas in the protosolar nebula followed by further thermal and aqueous processing on primordial parent bodies of carbonaceous, meteorites have produced an inventory of diverse organic compounds including classes now utilized in biochemistry. This inventory represents one possible set of reactants for chemical models for the origin of living systems on the early Earth. Evidence bearing on the history of meteoritic organic matter from astronomical observations and laboratory investigations will be reviewed and future research directions discussed.

  15. Organics In Meteorites

    Science.gov (United States)

    Chang, Sherwood

    1996-01-01

    The variety of classes of organic compounds that occur in carbonaceous meteorites suggests a rich pre-planetary chemistry with possible connections to interstellar, solar nebular and parent body processes. Structural diversity prevails within all classes examined in detail. Among amino acids for instance, all possible isomers are found up to species containing 4-6 carbon atoms, with abundances decreasing with increasing molecular weight. Such diversity seems limited to those carbonaceous meteorites which show evidence of having been exposed to liquid water; meteorites lacking such evidence also show much lower abundances and less structural diversity in their organic contents. This apparent dependency on water suggests a role for cometary ices in the chemical evolution of organic compounds on parent bodies. Measurements of the stable isotope compositions of C, H, N and S in classes of compounds and at the individual compound level show strong deviations from average chondritic values. These deviations are difficult to explain by solar system or parent body processes, and precedents for some of these isotopic anomalies exist in interstellar (e.g., high D/H ratios) and circumstellar chemistry. Therefore, presolar origins for much if not all of the meteoritic organic compounds (or their precursors) is a distinct possibility. In contrast, evidence of solar nebular origins is either lacking or suspect. Results from molecular and isotopic analyses of meteoritic organics, from laboratory simulations and from a model of interstellar grain reactions will be used to flesh out the hypothesis that this material originated with interstellar chemistry, was distributed within the early solar system as cometary ices, and was subsequently altered on meteorite parent bodies to yield the observed compounds.

  16. Metal/sulfide-silicate intergrowth textures in EL3 meteorites: Origin by impact melting on the EL parent body

    Science.gov (United States)

    van Niekerk, Deon; Keil, Klaus

    2011-10-01

    We document the petrographic setting and textures of Fe,Ni metal, the mineralogy of metallic assemblages, and the modal mineral abundances in the EL3 meteorites Asuka (A-) 881314, A-882067, Allan Hills 85119, Elephant Moraine (EET) 90299/EET 90992, LaPaz Icefield 03930, MacAlpine Hills (MAC) 02635, MAC 02837/MAC 02839, MAC 88136, Northwest Africa (NWA) 3132, Pecora Escarpment 91020, Queen Alexandra Range (QUE) 93351/QUE 94321, QUE 94594, and higher petrologic type ELs Dar al Gani 1031 (EL4), Sayh al Uhaymir 188 (EL4), MAC 02747 (EL4), QUE 94368 (EL4), and NWA 1222 (EL5). Large metal assemblages (often containing schreibersite and graphite) only occur outside chondrules and are usually intergrown with silicate minerals (euhedral to subhedral enstatite, silica, and feldspar). Sulfides (troilite, daubréelite, and keilite) are also sometimes intergrown with silicates. Numerous authors have shown that metal in enstatite chondrites that are interpreted to have been impact melted contains euhedral crystals of enstatite. We argue that the metal/sulfide-silicate intergrowths in the ELs we studied were also formed during impact melting and that metal in EL3s thus does not retain primitive (i.e., nebular) textures. Likewise, the EL4s are also impact-melt breccias. Modal abundances of metal in the EL3s and EL4s range from approximately 7 to 30 wt%. These abundances overlap or exceed those of EL6s, and this is consistent either with pre-existing heterogeneity in the parent body or with redistribution of metal during impact processes.

  17. Cathodoluminescence and Raman Spectromicroscopy of Forsterite in Tagish Lake Meteorite: Implications for Astromineralogy

    Directory of Open Access Journals (Sweden)

    Arnold Gucsik

    2016-01-01

    Full Text Available The Tagish Lake meteorite is CI/CM2 chondrite, which fell by a fireball event in January 2000. This study emphasizes the cathodoluminescence (CL and Raman spectroscopical properties of the Tagish Lake meteorite in order to classify the meteoritic forsterite and its relation to the crystallization processes in a parent body. The CL-zoning of Tagish Lake meteorite records the thermal history of chondrules and terrestrial weathering. Only the unweathered olivine is forsterite, which is CL-active. The variation of luminescence in chondrules of Tagish Lake meteorite implies chemical inhomogeneity due to low-grade thermal metamorphism. The blue emission center in forsterite due to crystal lattice defect is proposed as being caused by rapid cooling during the primary crystallization and relatively low-temperature thermal metamorphism on the parent body of Tagish Lake meteorite. This is in a good agreement with the micro-Raman spectroscopical data. A combination of cathodoluminescence and micro-Raman spectroscopies shows some potentials in study of the asteroidal processes of parent bodies in solar system.

  18. The formation and the evolution process of the Jilin meteorite

    International Nuclear Information System (INIS)

    Duyang, Z.Y.

    1983-01-01

    Based on the data from an integrated study by a multidisciplinary group on the Jilin meteorite, we discuss the following aspects concerning its formation and evolution: (1) The fractionation-condensation of the solar nebula was examined based on the condensation and solidification age and the mineral composition of the Jilin meteorite. (2) The thermometamorphic history of the Jilin parent body was discussed based on the data on the loss of rare gases, the chemical composition of the whole rock, the self-purification of rare-earth elements and the composition stability of olivine and orthopyroxene. (3) The cooling process of the Jilin parent body was analyzed according to the Ni content and the width of taenite, and the retentivity of argon and fission tracks in the minerals. (4) The breakup of the Jilin parent body and its cosmic ray irradiation history: Based on the measurements of the cosmogenic nuclides as He 3 , Ne/sup 20,21,22/, Ar 38 , Na 22 , Al 26 , Mn 54 , Mn 53 , Co 60 etc., a two-stage model of the irradiation history of the Jilin meteorite was proposed. From the data on the Jilin meteorite parent body of the first stage (the age = 10--11 MY and r = 10 m) and that of the second stage (the age = 0.3--0.5 MY and r = 80--90 cm). The relative positions of samples in the parent body, their burial depths as well as the post-atmospheric loss by ignition were determined. (5) The falling process of the Jilin meteorite: The orbits of the Jilin meteor in the solar system and in the atmosphere, and its falling process were discussed

  19. Density, porosity and magnetic susceptibility of the Košice meteorite shower and homogeneity of its parent meteoroid

    Czech Academy of Sciences Publication Activity Database

    Kohout, Tomáš; Havrila, K.; Tóth, J.; Husárik, M.; Gritsevich, M.; Britt, D.; Borovička, Jiří; Spurný, Pavel; Igaz, A.; Svoreň, J.; Kornoš, L.; Vereš, P.; Koza, J.; Zigo, P.; Gajdoš, Š.; Világi, J.; Čapek, David; Krišandová, Z.; Tomko, D.; Šilha, J.; Schunová, E.; Bodnárová, M.; Búzová, D.; Krejčová, T.

    93/94, April (2014), s. 96-100 ISSN 0032-0633 R&D Projects: GA MŠk LH12079 Institutional support: RVO:67985831 ; RVO:67985815 Keywords : porosity * density * H chondrite * meteorite * Kosice Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.875, year: 2014

  20. Iron and stony-iron meteorites

    DEFF Research Database (Denmark)

    Ruzicka, Alex M.; Haack, Henning; Chabot, Nancy L.

    2017-01-01

    By far most of the melted and differentiated planetesimals that have been sampled as meteorites are metal-rich iron meteorites or stony iron meteorites. The parent asteroids of these meteorites accreted early and differentiated shortly after the solar system formed, producing some of the oldest...... and interpretations for iron and stony iron meteorites (Plate 13.1). Such meteorites provide important constraints on the nature of metal-silicate separation and mixing in planetesimals undergoing partial to complete differentiation. They include iron meteorites that formed by the solidification of cores...... (fractionally crystallized irons), irons in which partly molten metal and silicates of diverse types were mixed together (silicate-bearing irons), stony irons in which partly molten metal and olivine from cores and mantles were mixed together (pallasites), and stony irons in which partly molten metal...

  1. Multiscale Organization and Isotopic Composition of Carbons in Acapulco and Lodran as Fingerprints of Their Parent Body Story

    Science.gov (United States)

    Charon, E.; Aléon, J.; Rouzaud, J. N.

    2012-09-01

    New structural and isotopic data recorded on carbon components of Acapulco and Lodran meteorites allow to propose a scenario of their parent body thermal story, with an impact induced introduction of CI-CM like IOM.

  2. Worlds beyond meteorite studies

    International Nuclear Information System (INIS)

    Lipschutz, M.E.

    1986-01-01

    Meteorites are of essential interest because they contain the oldest Solar System materials available for research and sample a wide range of parent bodies - exteriors and interiors - some primitive, some highly evolved. Meteorites carry decipherable records of certain solar and galactic effects and yield otherwise unobtainable data about the genesis, evolution, and composition of the Earth and other major planets, satellites, asteroids, and the Sun. Some contain inclusions tracing events from before the Solar System formed; others contain organic matter derived from giant molecular clouds in the interstellar medium. It is especially advantageous that meteorites occur on the Earth's surface, where the full spectrum of laboratory analytical techniques can be applied, ranging from the simplest to the most sophisticated. As the recently released report of the US National Commission on Space put it: If one picture is worth 10,000 words, then one sample is worth 10,000 pictures. Because of the interdisciplinary nature of meteorite studies - overlapping chemistry, physics, geology, and astronomy - no brief article can summarize the full scope of current research. After introducing some basic cosmochemical facts and approaches, this report will illustrate the nature of questions that cosmochemists ask and how they go about answering them. For reasons to be described, the author focuses on certain trace elements - especially Ag, Au, Bi, Cd, Co, Cs, In, Rb, Se, Te, Tl, and Zn - that are particularly responsive to relatively low temperature processes and that yield important genetic information

  3. Extraterrestrial Amino Acids in the Almahata Sitta Meteorite

    Science.gov (United States)

    Glavin, Daniel P.; Aubrey, Andrew D.; Callahan, Michael P.; Dworkin, Jason P.; Elsila, Jamie E.; Parker, Eric T.; Bada, Jeffrey L.

    2010-01-01

    Amino acid analysis of a meteorite fragment of asteroid 2008 TC3 called Almahata Sitta was carried out using reverse-phase liquid chromatography coupled with UV fluorescence detection and time-of-flight mass spectrometry (LC-FD/ToF-MS) as part of a sample analysis consortium. LC-FD/ToF-MS analyses of hot-water extracts from the meteorite revealed a complex distribution of two- to seven-carbon aliphatic amino acids and one- to three-carbon amines with abundances ranging from 0.5 to 149 parts-per-billion (ppb). The enantiomeric ratios of the amino acids alanine, R-amino-n-butyric acid (beta-ABA), 2-amino-2-methylbutanoic acid (isovaline), and 2-aminopentanoic acid (norvaline) in the meteorite were racemic (D/L approximately 1), indicating that these amino acids are indigenous to the meteorite and not terrestrial contaminants. Several other non-protein amino acids were also identified in the meteorite above background levels including alpha-aminoisobutyric acid (alpha-AIB), 4-amino-2- methylbutanoic acid, 4-amino-3-methylbutanoic acid, and 3-, 4-, and 5-aminopentanoic acid. The total abundances of isovaline and alpha-AIB in Almahata Sitta are 1000 times lower than the abundances of these amino acids found in the CM carbonaceous chondrite Murchison. The extremely low abundances and unusual distribution of five carbon amino acids in Almahata Sitta compared to Cl, CM, and CR carbonaceous chondrites may reflect extensive thermal alteration of amino acids on the parent asteroid by partial melting during formation or subsequent impact shock heating. It is also possible that amino acids were synthesized by catalytic reactions on the parent body after asteroid 2008 TC3 cooled to lower temperatures.

  4. Chiral Biomarkers in Meteorites

    Science.gov (United States)

    Hoover, Richard B.

    2010-01-01

    The chirality of organic molecules with the asymmetric location of group radicals was discovered in 1848 by Louis Pasteur during his investigations of the rotation of the plane of polarization of light by crystals of sodium ammonium paratartrate. It is well established that the amino acids in proteins are exclusively Levorotary (L-aminos) and the sugars in DNA and RNA are Dextrorotary (D-sugars). This phenomenon of homochirality of biological polymers is a fundamental property of all life known on Earth. Furthermore, abiotic production mechanisms typically yield recemic mixtures (i.e. equal amounts of the two enantiomers). When amino acids were first detected in carbonaceous meteorites, it was concluded that they were racemates. This conclusion was taken as evidence that they were extraterrestrial and produced by abiologically. Subsequent studies by numerous researchers have revealed that many of the amino acids in carbonaceous meteorites exhibit a significant L-excess. The observed chirality is much greater than that produced by any currently known abiotic processes (e.g. Linearly polarized light from neutron stars; Circularly polarized ultraviolet light from faint stars; optically active quartz powders; inclusion polymerization in clay minerals; Vester-Ulbricht hypothesis of parity violations, etc.). This paper compares the measured chirality detected in the amino acids of carbonaceous meteorites with the effect of these diverse abiotic processes. IT is concluded that the levels observed are inconsistent with post-arrival biological contamination or with any of the currently known abiotic production mechanisms. However, they are consistent with ancient biological processes on the meteorite parent body. This paper will consider these chiral biomarkers in view of the detection of possible microfossils found in the Orgueil and Murchison carbonaceous meteorites. Energy dispersive x-ray spectroscopy (EDS) data obtained on these morphological biomarkers will be

  5. A Propensity for n-omega-Amino Acids in Thermally-Altered Antarctic Meteorites

    Science.gov (United States)

    Burton, Aaron S.; Elsila, Jamie E.; Callahan, Michael P.; Martin, Mildred G.; Glavin, Daniel P.; Johnson, Natasha M.; Dworkin, Jason P.

    2012-01-01

    Carbonaceous meteorites are known to contain a wealth of indigenous organic molecules, including amino acids, which suggests that these meteorites could have been an important source of prebiotic organic material during the origins of life on Earth and possibly elsewhere. We report the detection of extraterrestrial amino acids in thermally-altered type 3 CV and CO carbonaceous chondrites and ureilites recovered from Antarctica. The amino acid concentrations of the thirteen Antarctic meteorites were generally less abundant than in more amino acid-rich CI, CM, and CR carbonaceous chondrites that experienced much lower temperature aqueous alteration on their parent bodies. In contrast to low-temperature aqueously-altered meteorites that show complete structural diversity in amino acids formed predominantly by Strecker-cyanohydrin synthesis, the thermally-altered meteorites studied here are dominated by small, straight-chain, amine terminal (n-omega-amino) amino acids that are not consistent with Strecker formation. The carbon isotopic ratios of two extraterrestrial n-omega-amino acids measured in one of the CV chondrites are consistent with C-13-depletions observed previously in hydrocarbons produced by Fischer-Tropsch type reactions. The predominance of n-omega-amino acid isomers in thermally-altered meteorites hints at cosmochemical mechanisms for the preferential formation and preservation of a small subset of the possible amino acids.

  6. Enrichment of Non-Terrestrial L-Proteinogenic Amino Acids by Aqueous Alteration on the Tagish Lake Meteorite Parent Body

    Science.gov (United States)

    Glavin, Daniel P.; Elsila, Jamie E.; Burton, Aaron S.; Callahan, Michael P.; Dworkin, Jason P.; Herd, Christopher D. K.

    2012-01-01

    The distribution and isotopic and enantiomeric compositions of amino acids found in three distinct fragments of the Tagish Lake C2-type carbonaceous chondrite were investigated via liquid chromatography fluorescence detection time-of-flight mass spectrometry and gas chromatography isotope ratio mass spectrometry. Large L-enantiomeric excesses (L(sub ee) approx. 43 to 59%) of the a-hydrogen aspartic and glutamic amino acids were measured in Tagish Lake, whereas alanine, another alpha-hydrogen protein amino acid, was found to be nearly racemic (D approx. L) using both techniques. Carbon isotope measurements of D- and L-aspartic acid and D- and L-alanine in Tagish Lake fall well outside of the terrestrial range and indicate that the measured aspartic acid enantioenrichment is indigenous to the meteorite. Alternate explanations for the Lexcesses of aspartic acid such as interference from other compounds present in the sample, analytical biases, or terrestrial amino acid contamination were investigated and rejected. These results can be explained by differences in the solid-solution phase behavior of aspartic acid, which can form conglomerate enantiopure solids during crystallization, and alanine, which can only form racemic crystals.

  7. Organic Chemistry of Carbonaceous Meteorites

    Science.gov (United States)

    Cronin, John R.

    2001-01-01

    Chiral and carbon-isotopic analyses of isovaline have been carried out on numerous samples of the Murchison and one sample of the Murray carbonaceous chondrite. The isovaline was found to be heterogeneous with regard to enantiomeric excess (ee) both between samples and within a single Murchison sample. L-Excesses ranging from 0 to 15% were observed. The isovaline delta(sup 13) C was found to be about +18%. No evidence was obtained suggesting terrestrial contamination in the more abundant L-enantiomer. A correlation was observed between isovaline (also alpha - aminoisobutyric acid) concentration and PCP content of five CM chondrites. It is suggested that isovaline, along with other meteoritic a-methyl amino acids with ee, are of presolar origin. The possible formation of ee in extraterrestrial amino acids by exposure to circularly polarized light or by magnetochiral photochemistry is discussed. Key words: Murchison meteorite, Murray meteorite, amino acids, isovaline, chirality, carbon isotopes, PCP.

  8. ON THE EFFECT OF GIANT PLANETS ON THE SCATTERING OF PARENT BODIES OF IRON METEORITE FROM THE TERRESTRIAL PLANET REGION INTO THE ASTEROID BELT: A CONCEPT STUDY

    International Nuclear Information System (INIS)

    Haghighipour, Nader; Scott, Edward R. D.

    2012-01-01

    In their model for the origin of the parent bodies of iron meteorites, Bottke et al. proposed differentiated planetesimals, formed in 1-2 AU during the first 1.5 Myr, as the parent bodies, and suggested that these objects and their fragments were scattered into the asteroid belt as a result of interactions with planetary embryos. Although viable, this model does not include the effect of a giant planet that might have existed or been growing in the outer regions. We present the results of a concept study where we have examined the effect of a planetary body in the orbit of Jupiter on the early scattering of planetesimals from the terrestrial region into the asteroid belt. We integrated the orbits of a large battery of planetesimals in a disk of planetary embryos and studied their evolutions for different values of the mass of the planet. Results indicate that when the mass of the planet is smaller than 10 M ⊕ , its effects on the interactions among planetesimals and planetary embryos are negligible. However, when the planet mass is between 10 and 50 M ⊕ , simulations point to a transitional regime with ∼50 M ⊕ being the value for which the perturbing effect of the planet can no longer be ignored. Simulations also show that further increase of the mass of the planet strongly reduces the efficiency of the scattering of planetesimals from the terrestrial planet region into the asteroid belt. We present the results of our simulations and discuss their possible implications for the time of giant planet formation.

  9. Detection of a meteorite 'stream' - Observations of a second meteorite fall from the orbit of the Innisfree chondrite

    Science.gov (United States)

    Halliday, I.

    1987-03-01

    The first observational evidence of multiple meteorite falls from the same orbit is adduced from the February 6, 1980 fall of a meteorite precisely 3 yr after the fall of the Innisfree meteorite. Due consideration of the detection probability for two related objects with the meteorite camera network in western Canada suggests that the Innisfree brecciated LL chondrite was a near-surface fragment from a parent object whose radius was of the order of several tens of meters. A meteorite mass of 1.8 kg is predicted for the new object, whose recovery in the vicinity of Ridgedale, Saskatchewan, is now sought for the sake of comparison with the Innisfree chondrite.

  10. Terrestrial and exposure histories of Antarctic meteorites

    International Nuclear Information System (INIS)

    Nishiizumi, K.

    1986-01-01

    Records of cosmogenic effects were studied in a large suite of Antarctic meteorites. The cosmogenic nuclide measurements together with cosmic ray track measurements on Antartic meteorites provide information such as exposure age, terrestrial age, size and depth in meteoroid or parent body, influx rate in the past, and pairing. The terrestrail age is the time period between the fall of the meteorite on the Earth and the present. To define terrestrial age, two or more nuclides with different half-lives and possibly noble gases are required. The cosmogenic radionuclides used are C-14, Kr-81, Cl-36, Al-26, Be-10, Mn-53, and K-40

  11. Terrestrial and exposure histories of Antarctic meteorites

    Science.gov (United States)

    Nishiizumi, K.

    1986-01-01

    Records of cosmogenic effects were studied in a large suite of Antarctic meteorites. The cosmogenic nuclide measurements together with cosmic ray track measurements on Antartic meteorites provide information such as exposure age, terrestrial age, size and depth in meteoroid or parent body, influx rate in the past, and pairing. The terrestrail age is the time period between the fall of the meteorite on the Earth and the present. To define terrestrial age, two or more nuclides with different half-lives and possibly noble gases are required. The cosmogenic radionuclides used are C-14, Kr-81, Cl-36, Al-26, Be-10, Mn-53, and K-40.

  12. Principles of meteoritics

    CERN Document Server

    Krinov, E L

    1960-01-01

    Principles of Meteoritics examines the significance of meteorites in relation to cosmogony and to the origin of the planetary system. The book discusses the science of meteoritics and the sources of meteorites. Scientists study the morphology of meteorites to determine their motion in the atmosphere. The scope of such study includes all forms of meteorites, the circumstances of their fall to earth, their motion in the atmosphere, and their orbits in space. Meteoric bodies vary in sizes; in calculating their motion in interplanetary space, astronomers apply the laws of Kepler. In the region of

  13. SNC meteorites: Clues to martian petrologic evolution

    International Nuclear Information System (INIS)

    McSween, H.Y. Jr.

    1985-01-01

    The shergottites, nakhlites, and Chassigny (SNC meteorites) are apparently cumulate mafic and ultramafic rocks that crystallized at shallow levels in the crust of their parent body. The mineralogy and chemistry of these meteorites are remarkably like equivalent terrestrial rocks, although their ratios of Fe/(Fe+Mg) and certain incompatible elements and their oxygen isotopic compositions are distinctive. All have crystallization ages of 1.3 b.y. or younger and formed from magmas produced by partial melting of previously fractionated source regions. Isotope systematics suggest that the SNC parent body had a complex and protracted thermal history spanning most of geologic time. Some meteorites have been severely shock metamorphosed, and all were ejected from their parent body at relatively recent times, possibly in several impact events. Late crystallization ages, complex petrogenesis, and possible evidence for a large gravitational field suggest that these meteorites are derived from a large planet. Trapped gases in shergottite shock melts have compositions similar to the composition measured in the Martian atmosphere. Ejection of Martian meteorites may have been accomplished by acceleration of near-surface spalls or other mechanisms not fully understood. If SNC meteorites are of Martian origin, they provide important information on planetary composition and evolution. The bulk composition and redox state of the Martian mantle, as constrained by shergottite phase equilibria, must be more earthlike than most current models. Planetary thermal models should benefit from data on the abundances of radioactive heat sources, the melting behavior of the mantle, and the timing of planetary differentiation

  14. Constraining the Thermochronological History of the IAB Parent Body: High Resolution Ar-40-Ar-39 Ages on Plagioclase Separates from Silicate Inclusions of IAB Meteorites

    Science.gov (United States)

    Vogel, N.; Renne, P. R.

    2004-12-01

    The processes that led to the assembly of primitive inclusions in a once molten metal matrix as represented by IAB meteorites have not yet been fully understood [1]. Ar-Ar dating of the inclusions provides important information about the thermal history of the IAB parent body [e.g., 2, 3], but the analysis of bulk inclusions, the standard procedure in the past, is often impaired by excess 40Ar and redistribution or loss of K and/or Ar during the history of the meteoriod and in the reactor. To minimize these problems, we prepared from silicate inclusions of four IABs pure plagioclase separates of different grain sizes and quality grades. On these we performed high resolution stepwise Ar-40-Ar-39 dating. Preliminary ages for the different separates of the inclusions are, in Ma, 4540(11) to 4459(12) for Caddo County, 4500(20) to 4380(30) for Landes, 4440(50) to 4340(30) for Ocotillo, and 4480(40) to 4200(30) and 4430(30) to 4300(30) for CDC2 and CDC1, respectively. The age ranges might reflect the residence time of each inclusion in the K-Ar blocking temperature range (ca. 600 K), and is narrowest for Caddo County, being also the oldest inclusion studied by us. Assuming that IABs resulted from a collision of a molten metal body with a chondritic planetesimal [4], Caddo County could represent a surface sample explaining the early and fast cooling, whereas the other samples might have been buried deeper within the IAB body, subject to prolonged residence at elevated temperatures. If IABs formed in impact metal melt pools peppered with chondritic host material [5] the different cooling ages, and age ranges recorded in each inclusion could reflect residence times in a certain metal melt pool, which indirectly would translate into pool sizes and the energies released by the previous impacts. Also, there may have been more than one IAB parent body. Whatever process led to the formation of IAB meteorites was active already very early in the history of the solar system, in

  15. Annual Occurrence of Meteorite-Dropping Fireballs

    Science.gov (United States)

    Konovalova, Natalia; Jopek, Tadeusz J.

    2016-07-01

    The event of Chelyabinsk meteorite has brought about change the earlier opinion about limits of the sizes of potentially dangerous asteroidal fragments that crossed the Earth's orbit and irrupted in the Earth's atmosphere making the brightest fireball. The observations of the fireballs by fireball networks allows to get the more precise data on atmospheric trajectories and coordinates of predicted landing place of the meteorite. For the reason to search the periods of fireball activity is built the annual distribution of the numbers of meteorites with the known fall dates and of the meteorite-dropping fireballs versus the solar longitude. The resulting profile of the annual activity of meteorites and meteorite-dropping fireballs shows several periods of increased activity in the course of the year. The analysis of the atmospheric trajectories and physical properties of sporadic meteorite-dropping fireballs observed in Tajikistan by instrumental methods in the summer‒autumn periods of increased fireballs activity has been made. As a result the structural strength, the bulk density and terminal mass of the studied fireballs that can survive in the Earth atmosphere and became meteorites was obtained. From the photographic IAU MDC_2003 meteor database and published sources based on the orbit proximity as determined by D-criterion of Southworth and Hawkins the fireballs that could be the members of group of meteorite-dropping fireballs, was found. Among the near Earth's objects (NEOs) the searching for parent bodies for meteorite-dropping fireballs was made and the evolution of orbits of these objects in the past on a long interval of time was investigated.

  16. Kosice meteorite analysis

    International Nuclear Information System (INIS)

    Sitek, J.; Degmova, J.; Dekan, J.

    2011-01-01

    Meteorite Kosice fell down 28 th of February 2010 near the Kosice and represents an unique find, because the last fall of meteorite was observed in Slovakia at the year 1895. It supposes that for this kind of meteorite the orbit in cosmic space could be calculated. This is one of most important part because until now 13 places of meteorite find are known in the world of which cosmic orbit in space have been calculated. Slovakia is member of international bolide net, dealing with meteorite analysis in Middle Europe .Analysis of Kosice meteorite will also concern at the long live and short live nuclides. Results should be a contribution to determination of radiation and formative ages. From structural analysis of meteorite it will be possible to compare it with similar types of meteorites. In this work Moessbauer spectroscopy will be used for phase analysis from point of view iron contain components with the aim to identify magnetic and non magnetic fractions. From the analysis of magnetic part we can find that the first sextet with hyperfine magnetic field 33.5 T corresponds to bcc Fe-Ni alloy (kamacite) and second with field 31.5 T to FeS (triolite). Meteorites with mentioned composition belong to the mineral group of chondrites. Comparing our parameters with results of measurements at the similar meteorites we can conclude that Kosice meteorite contains the same components. According all Moessbauer parameters we can also include this meteorite in the mineral group of chondrites. (authors)

  17. Meteorites as space probes

    International Nuclear Information System (INIS)

    Jaques, A.L.

    1982-01-01

    Meteorites are a major source of information on evolution of the solar system. The BMR-Hollmayer meteorite collection consists mainly of chondrites but also includes a carbonaceous chondrite and a ureilite from the achondrite group. The mineralogy and chemical composition of the meteorites have been studied

  18. Age determination of meteorites using radioactive nuclides

    International Nuclear Information System (INIS)

    Tanimizu, Masaharu

    2002-01-01

    Recently, the precise isotope ratios of some refractory elements in meteorites have been reported using inductively coupled plasma mass spectrometry. The in situ decay of 182 Hf (T 1/2 =9 Myr), which was produced at the latest nucleosynthesis, is recognized in many meteorites as isotopic anomalies of its daughter isotope, 182 W. The degrees of relative 182 W isotopic deviation in extra-terrestrial and terrestrial silicate samples vary from +0.3% to ±0% related to the size of their parent bodies. One ready interpretation of its correlation is the difference in timing of metal-silicate separation in the parent bodies. Between the earth and meteorite parent bodies, the difference is calculated to be about four times of the half-life of 182 Hf, equivalent to 36 Myr. (author)

  19. Classification of Meteorites and Micrometeorites

    Science.gov (United States)

    Maurette, Michel

    Archeologists only started to trace back successfully the advance of the Roman legions, trade patterns and the evolution of manufacturing techniques in Roman time, once they found an efficient scheme of classification for the fragments of amphora used to transport wine for the soldiers. Similarly, the classification of meteorites and micrometeorites is an essential step in the exploitation of these extraterrestrial debris. We recall that one of the main objectives of meteoriticists over the last 30 years was to find the most primitive objects of the solar system, which have been the least reprocessed since the formation of the early solar nebula, with the view to exploit them as reliable archivist of our distant past. This section outlines some of the methods used to classify meteorites and Antarctic micrometeorites. It also summarizes some of the key features of the surprisingly simple relationship between micrometeorites and a relatively rare group of stony meteorites, the hydrous carbonaceous CM-type chondrites, which was only confirmed recently after the study of the Concordia micrometeorites collected in central Antarctica in January 2002. A more technical discussion of this relationship presented in Sect. 25 will allow its extension to the smaller micrometeorites collected by NASA in the stratosphere. The book of Wasson (1985) is still one of the best monographs about meteorites.

  20. Moessbauer study of El-Bahrain meteorite

    International Nuclear Information System (INIS)

    Bahgat, A.A.; Ahmed, M.A.; Ramadan, T.M.

    2000-01-01

    A stone of brick-like shape, measuring roughly 25 x 12.5 x 10.5 cm 3 and weighing 14 kg was found in 1983, in the western desert of Egypt. The meteorite was named El-Bahrain meteorite and classified as L-chondrite. Principal constituents of El-Bahrain meteorite have been studied by means of Moessbauer spectroscopy. The chemical composition as obtained by the conventional wet analyses of L-chondritic meteorites showed that the meteorite contains 23,38% Fe and 1.23% Ni. While the analysis of the atomic absorption showed the presence of 27.03% as a total iron. The Moessbauer analysis of El-Bahrain meteorite showed that the iron constituent minerals were determined to be olivine, metallic iron-nickel alloys (kamacite, taenite and tetrataenite), ferrous sulfide (troilite) and weathering products such as maghemite and nanocrystalline hematite. The structure of meteoritic iron obtained by the Moessbauer analysis has been discussed on the basis of these constituents. (author)

  1. Iron and stony-iron meteorites

    DEFF Research Database (Denmark)

    Benedix, Gretchen K.; Haack, Henning; McCoy, T. J.

    2014-01-01

    Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich...... sampling of the deep interiors of differentiated asteroids. Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar...... to that continuing on Earth – although on much smaller length- and timescales – with melting of the metal and silicates; differentiation into core, mantle, and crust; and probably extensive volcanism. Iron and stony-iron meteorites are our only available analogues to materials found in the deep interiors of Earth...

  2. Diradicaloids in the insoluble organic matter from the Tagish Lake meteorite: Comparison with the Orgueil and Murchison meteorites

    Science.gov (United States)

    Binet, L.; Gourier, D.; Derenne, S.; Pizzarello, S.; Becker, L.

    2004-10-01

    The radicals in the insoluble organic matter (IOM) from the Tagish Lake meteorites were studied by electron paramagnetic resonance and compared to those existing in the Orgueil and Murchison meteorites. As in the Orgueil and Murchison meteorites, the radicals in the Tagish Lake meteorite are heterogeneously distributed and comprise a substantial amount (~42%) of species with a thermally acessible triplet state and with the same singlet-triplet gap, ?E ??0.1 eV, as in the Orgueil and Murchison meteorites. These species were identified as diradicaloid moieties. The existence of similar diradicaloid moieties in three different carbonaceous chondrites but not in terrestrial IOM strongly suggests that these moieties could be "fingerprints" of the extraterrestrial origin of meteoritic IOM and markers of its synthetic pathway before its inclusion into a parent body.

  3. Antarctic Meteorite Newsletter

    Science.gov (United States)

    Lindstrom, Marilyn

    2000-01-01

    This newsletter contains something for everyone! It lists classifications of about 440 meteorites mostly from the 1997 and 1998 ANSMET (Antarctic Search for Meteorites) seasons. It also gives descriptions of about 45 meteorites of special petrologic type. These include 1 iron, 17 chondrites (7 CC, 1 EC, 9 OC) and 27 achondrites (25 HED, UR). Most notable are an acapoloite (GRA98028) and an olivine diogenite (GRA98108).

  4. Chirality of meteoritic free and IOM-derived monocarboxylic acids and implications for prebiotic organic synthesis

    Science.gov (United States)

    Aponte, José C.; Tarozo, Rafael; Alexandre, Marcelo R.; Alexander, Conel M. O.'D.; Charnley, Steven B.; Hallmann, Christian; Summons, Roger E.; Huang, Yongsong

    2014-04-01

    The origin of homochirality and its role in the development of life on Earth are among the most intriguing questions in science. It has been suggested that carbonaceous chondrites seeded primitive Earth with the initial organic compounds necessary for the origin of life. One of the strongest pieces of evidence supporting this theory is that certain amino acids in carbonaceous chondrites display a significant L-enantiomeric excess (ee), similar to those use by terrestrial life. Analyses of ee in meteoritic molecules other than amino acids would shed more light on the origins of homochirality. In this study we investigated the stereochemistry of two groups of compounds: (1) free monocarboxylic acids (MCAs) from CM2 meteorites LON 94101 and Murchison; and (2) the aliphatic side chains present in the insoluble organic matter (IOM) and extracted in the form of monocarboxylic acids (MCAs) from EET 87770 (CR2) and Orgueil (CI1). Contrary to the well-known ee observed for amino acids in meteorites, we found that meteoritic branched free and IOM-derived MCAs with 5-8 carbon atoms are essentially racemic. The racemic nature of these compounds is used to discuss the possible influence of ultraviolet circularly polarized light (UVCPL) and aqueous alterations on the parent body on chirality observed in in carbonaceous chondrites.

  5. Thermoluminescence of meteorites and their orbits

    International Nuclear Information System (INIS)

    Melcher, C.L.

    1981-01-01

    The thermolunimescence (TL) levels of 45 ordinary chondrites were measured to obtain information about the meteorite orbits. The low-temperature TL reaches equilibrium while the meteorite is in space and reflects the temperature of the meteorite at perihelion. Samples of Pribram, Lost City, and Innisfree, whose orbits are accurately known, were used as control samples. The TL levels in 40 out of 42 meteorites are similar to the three control samples, indicating that the vast majority of ordinary chondrites that survive atmospheric entry have perihelia similar to three known orbits, i.e., in the range 0.8-1 AU. The effects of albedo and rotation are also considered. A simple model indicates that temperature gradients of 1-2 0 K/cm are possible in slowly rotating meteoroids and such a temperature gradient is consistent with the unusually large TL gradient measured in the Farmville meteorite. Since slow rotation rates are improbable, other possibilities are examined but no satisfactory explanation has been found. The TL level measured in the Malakal meteorite is two orders of magnitude lower than control samples and is best explained by thermal draining due to solar heating in an orbit with a small perihelion distance. The perihelion is estimated to be approx. 0.5-0.6 AU. (orig.)

  6. Isotopic variations in primitive meteorites

    International Nuclear Information System (INIS)

    Clayton, R.N.; Chicago Univ., IL; Chicago Univ., IL

    1981-01-01

    The presence of large internal 16 O variability in ordinary chondrites greatly extends the range of meteorite types in which this phenomenon has been observed. These results may lead to identification of major gas and dust reservoirs in the cloud from which the Solar System formed. The demonstration that live 107 Pd was present in the differentiated parent bodies of some iron meteorites supports the million year time scale between a major nucleosynthetic event and Solar System formation, as implied by the presence of live 26 Al in carbonaceous chondrites. However, the variability of radiogenic 26 Mg abundances in these meteorites makes it clear that the data cannot be interpreted simply in terms of time variations. Models of nucleosynthesis for elements from calcium to the iron peak should be aided by the new observations of abundances of titanium isotopes. Progress has been made in establishing the carrier phases of isotopically anomalous xenon and krypton. The apparent location of anomalous xenon and 14 N-rich nitrogen in identical carriers supports the notion that nucleosynthetic anomalies in nitrogen are also present in Allende. (author)

  7. Foundations of Forensic Meteoritics

    Science.gov (United States)

    Treiman, A. H.

    1992-07-01

    It may be useful to know if a meteorite was found at the site where it fell. For instance, the polymict ureilites North Haig and Nilpena were found 1100 km apart, yet are petrologically identical [1]. Could this distance represent transport from a single strewn field, or does it represent distinct fall sites? A meteorite may contain sufficient clues to suggest some characteristics of its fall site. If these inferences are inconsistent with the find site, one may infer that the meteorite has been transported. It will likely be impossible to determine the exact fall site of a transported meteorite. Data relevant to a meteorite's fall site may be intrinsic to the meteorite, or acquired at the site. For instance, an intrinsic property is terrestrial residence age (from abundances of cosmogenic radioisotopes and their decay products); a meteorite's terrestrial residence age must be the same or less than that of the surface on which it fell. After falling, a meteorite may acquire characteristic telltales of terrestrial geological, geochemical, and biological processes. These telltale clues may include products of chemical weathering, adhering geological materials, biological organisms living (or once living) on the meteorite, and biological materials adhering to (but never living on) the meteorite. The effects of chemical weathering, present in all but the freshest finds, range from slight rusting to extensive decomposition and veining The ages of weathering materials and veins, as with terrestrial residence ages above, must be less than the age of the fall surface. The mineralogy and chemistry, elemental and isotopic, of weathering materials will differ according to the mineralogy and composition of the meteorite, and the mineralogy, geochemistry, hydrology, and climate of the fall site. Weathering materials may also vary as climate changes and may vary among the microenvironments associated with a meteorite on the Earth's surface. Geological materials (rock, sediment

  8. Radar-Enabled Recovery of the Sutters Mill Meteorite, a Carbonaceous Chondrite Regolith Breccia

    Science.gov (United States)

    Jenniskens, Petrus M.; Fries, Marc D.; Yin, Qing-Zhu; Zolensky, Michael E.; Krot, Alexander N.; Sandford, Scott A.; Sears, Derek; Beauford, Robert; Ebel, Denton S.; Friedrich, Jon M.; hide

    2012-01-01

    Doppler weather radar imaging enabled the rapid recovery of the Sutter's Mill meteorite after a rare 4-kiloton of TNT-equivalent asteroid impact over the foothills of the Sierra Nevada in northern California. The recovered meteorites survived a record high-speed entry of 28.6 kilometers per second from an orbit close to that of Jupiter-family comets (Tisserand's parameter = 2.8 +/- 0.3). Sutter's Mill is a regolith breccia composed of CM (Mighei)-type carbonaceous chondrite and highly reduced xenolithic materials. It exhibits considerable diversity of mineralogy, petrography, and isotope and organic chemistry, resulting from a complex formation history of the parent body surface. That diversity is quickly masked by alteration once in the terrestrial environment but will need to be considered when samples returned by missions to C-class asteroids are interpreted.

  9. Magnetism in meteorites

    Science.gov (United States)

    Herndon, J. M.; Rowe, M. W.

    1974-01-01

    An overview is presented of magnetism in meteorites. A glossary of magnetism terminology followed by discussion of the various techniques used for magnetism studies in meteorites are included. The generalized results from use of these techniques by workers in the field are described. A brief critical analysis is offered.

  10. Pigeonholing planetary meteorites: The lessons of misclassification of EET87521 and ALH84001

    Science.gov (United States)

    Lindstrom, M. M.; Treiman, A. H.; Mittlefehldt, D. W.

    1994-01-01

    The last few years have provided two noteworthy examples of misclassifications of achondritic meteorites because the samples were new kinds of meteorites from planetary rather than asteroidal parent bodies. Basaltic lunar meteorite EET87521 was misclassified as a eucrite and SNC (martian) orthopyroxenite ALH84001 was misclassified as a diogenite. In classifying meteorites we find what we expect: we pigeonhole meteorites into known categories most of which were derived from the more common asteroidal meteorites. But the examples of EET8752 and ALH84001 remind us that planets are more complex than asteroids and exhibit a wider variety of rock types. We should expect variety in planetary meteorites and we need to know how to recognize them when we have them. Our intent here is to show that our asteroidal perspective is inappropriate for planetary meteorites.

  11. Meteors, meteorites and cosmic dust

    International Nuclear Information System (INIS)

    Lebedinets, V.N.

    1987-01-01

    The problem of meteorite origin and meteorite composition is discussed. Nowadays, most scientists suppose that the giant Oort cloud consisting of ice comet nuclei is the sourse of the meteor matter. A principle unity of the matter of meteorites falling to the Earth and cosmic dust is noted as well as that of meteorite bodies evaporating in the atmosphere and bearing meteors and bodies

  12. Meteorite falls in Africa

    Science.gov (United States)

    Khiri, Fouad; Ibhi, Abderrahmane; Saint-Gerant, Thierry; Medjkane, Mohand; Ouknine, Lahcen

    2017-10-01

    The study of meteorites provides insight into the earliest history of our solar system. From 1800, about the year meteorites were first recognized as objects falling from the sky, until December 2014, 158 observed meteorite falls were recorded in Africa. Their collected mass ranges from 1.4 g to 175 kg with the 1-10 kg cases predominant. The average rate of African falls is low with only one fall recovery per 1.35-year time interval (or 0.023 per year per million km2). This African collection is dominated by ordinary chondrites (78%) just like in the worldwide falls. The seventeen achondrites include three Martian meteorite falls (Nakhla of Egypt, Tissint of Morocco and Zagami of Nigeria). Observed Iron meteorite falls are relatively rare and represent only 5%. The falls' rate in Africa is variable in time and in space. The number of falls continues to grow since 1860, 80% of which were recovered during the period between 1910 and 2014. Most of these documented meteorite falls have been recovered from North-Western Africa, Eastern Africa and Southern Africa. They are concentrated in countries which have a large surface area and a large population with a uniform distribution. Other factors are also favorable for observing and collecting meteorite falls across the African territory, such as: a genuine meteorite education, a semi-arid to arid climate (clear sky throughout the year most of the time), croplands or sparse grasslands and possible access to the fall location with a low percentage of forest cover and dense road network.

  13. Meteorites, Ice, and Antarctica

    Science.gov (United States)

    Cassidy, William A.

    2003-08-01

    Bill Cassidy led meteorite recovery expeditions in the Antarctic for fifteen years and his searches have resulted in the collection of thousands of meteorite specimens from the ice. This personal account of his field experiences on the U.S. Antarctic Search for Meteorites Project reveals the influence the work has had on our understanding of the moon, Mars and the asteroid belt. Cassidy describes the hardships and dangers of fieldwork in a hostile environment, as well as the appreciation he developed for its beauty. William Cassidy is Emeritus Professor of Geology and Planetary Science at the University of Pittsburgh. He initiated the U.S. Antarctic Search for Meteorites (ANSMET) nroject and led meteorite recovery expeditions in Antarctica in1976. His name is found attached to a mineral (cassidyite), on the map of Antarctica (Cassidy Glacier), and in the Catalog of Asteroids (3382 Cassidy). Profiled in "American Men of Science," and "Who's Who in America," he is also a recipient of The Antarctic Service Medal from the United States and has published widely in Science, Meteoritics and Planetary Science, and The Journal of Geophysical Research.

  14. The Meteoritical Bulletin, No. 103

    Science.gov (United States)

    Ruzicka, Alex; Grossman, Jeffrey; Bouvier, Audrey; Agee, Carl B.

    2017-05-01

    Meteoritical Bulletin 103 contains 2582 meteorites including 10 falls (Ardón, Demsa, Jinju, Križevci, Kuresoi, Novato, Tinajdad, Tirhert, Vicência, Wolcott), with 2174 ordinary chondrites, 130 HED achondrites, 113 carbonaceous chondrites, 41 ureilites, 27 lunar meteorites, 24 enstatite chondrites, 21 iron meteorites, 15 primitive achondrites, 11 mesosiderites, 10 Martian meteorites, 6 Rumuruti chondrites, 5 ungrouped achondrites, 2 enstatite achondrites, 1 relict meteorite, 1 pallasite, and 1 angrite, and with 1511 from Antarctica, 588 from Africa, 361 from Asia, 86 from South America, 28 from North America, and 6 from Europe. Note: 1 meteorite from Russia was counted as European. The complete contents of this bulletin (244 pages) are available on line. Information about approved meteorites can be obtained from the Meteoritical Bulletin Database (MBD) available on line at meteor/">http://www.lpi.usra.edu/meteor/.

  15. A petrogenetic model of the relationships among achondritic meteorites

    Science.gov (United States)

    Stolper, E.; Hays, J. F.; Mcsween, H. Y., Jr.

    1979-01-01

    Petrological evidence is used to support the hypothesis that although the magma source regions and parent bodies of basaltic achondrite, shergottite, nakhlite, and chassignite meteorites are clearly distinct, they may be simply related. It is proposed that the peridotites which on partial melting generated the parent magmas of the shergottite meteorites differed from those which gave rise to eucritic magmas by being enriched in a component rich in alkalis and other volatiles. Similarly, the source regions of the parent magmas of the nakhlite and chassignite meteorites differed from those on the shergottite parent body by being still richer in this volatile-rich component. These regions could have been related by processes such as mixture of variable amounts of volatile-rich and volatile-poor components in planetary or nebular settings, or alternatively by variable varying degrees of volatile loss from volatile-rich materials.

  16. The Thermal Properties of CM Carbonaceous Chondrites

    Science.gov (United States)

    Britt, D. T.; Opeil, C.

    2017-12-01

    The physical properties of asteroid exploration targets are fundamental parameters for developing models, planning observations, mission operations, reducing operational risk, and interpreting mission results. Until we have returned samples, meteorites represent our "ground truth" for the geological material we expect to interact with, sample, and interpret on the surfaces of asteroids. The physical properties of the volatile-rich carbonaceous chondrites (CI, C2, CM, and CR groups) are of particular interest because of their high resource potential. We have measured the thermal conductivity, heat capacity and thermal expansion of five CM carbonaceous chondrites (Murchison, Murray, Cold Bokkeveld, NWA 7309, Jbilet Winselwan) at low temperatures (5-300 K) to mimic the conditions in the asteroid belt. The mineralogy of these meteorites are dominated by abundant hydrous phyllosilicates, but also contain anhydrous minerals such as olivine and pyroxene found in chondrules. The thermal expansion measurements for all these CMs indicate a substantial increase in meteorite volume as temperature decreases from 230 - 210 K followed by linear contraction below 210 K. Such transitions were unexpected and are not typical for anhydrous carbonaceous chondrites or ordinary chondrites. Our thermal diffusivity results compare well with previous estimates for similar meteorites, where conductivity was derived from diffusivity measurements and modeled heat capacities; our new values are of a higher precision and cover a wider range of temperatures.

  17. Diamond xenolith and matrix organic matter in the Sutter's Mill meteorite measured by C-XANES

    Science.gov (United States)

    Kebukawa, Yoko; Zolensky, Michael E.; Kilcoyne, A. L. David; Rahman, Zia; Jenniskens, Peter; Cody, George D.

    2014-11-01

    The Sutter's Mill (SM) meteorite fell in El Dorado County, California, on April 22, 2012. This meteorite is a regolith breccia composed of CM chondrite material and at least one xenolithic phase: oldhamite. The meteorite studied here, SM2 (subsample 5), was one of three meteorites collected before it rained extensively on the debris site, thus preserving the original asteroid regolith mineralogy. Two relatively large (10 μm sized) possible diamond grains were observed in SM2-5 surrounded by fine-grained matrix. In the present work, we analyzed a focused ion beam (FIB) milled thin section that transected a region containing these two potential diamond grains as well as the surrounding fine-grained matrix employing carbon and nitrogen X-ray absorption near-edge structure (C-XANES and N-XANES) spectroscopy using a scanning transmission X-ray microscope (STXM) (Beamline 5.3.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory). The STXM analysis revealed that the matrix of SM2-5 contains C-rich grains, possibly organic nanoglobules. A single carbonate grain was also detected. The C-XANES spectrum of the matrix is similar to that of insoluble organic matter (IOM) found in other CM chondrites. However, no significant nitrogen-bearing functional groups were observed with N-XANES. One of the possible diamond grains contains a Ca-bearing inclusion that is not carbonate. C-XANES features of the diamond-edges suggest that the diamond might have formed by the CVD process, or in a high-temperature and -pressure environment in the interior of a much larger parent body.

  18. Antarctic Meteorite Newsletter. Volume 20

    Science.gov (United States)

    Lindstrom, Marilyn M.; Satterwhite, Cecilia E.

    1997-01-01

    The availability of 116 new meteorites from the 1994-1996 collections is announced. There are 4 special chondrites, 2 carbonaceous chondrites, and 1 achondrite among the new meteorites. Also included is a redescription of Lodranite GRA95209.

  19. Quantitative FT-IR Analysis for Chondritic Meteorites: Search for C_60 in Meteorites

    Directory of Open Access Journals (Sweden)

    Chunglee Kim

    1998-06-01

    Full Text Available Infrared absorption spectra of 9 bulk samples and 3 acid residues of meteorites were obtained in the mid-infrared region (4000 ~ 400 cm^(-1. From the known composition of meteorites studied, the possible absorption modes were investigated. Most bands of bulk samples occur in the region below 1200 cm^(-1 and they are due to metallic oxides and silicates. The spectra of each group can be distinguished by its own characteristic bands. Acid residues show very distinct features from their bulk samples, and absorption bands due to organic compounds are not evident in their spectra. Quantitative analyses for two carbonaceous (Allende CV3 and Murchison CM2 and one ordinary (Carraweena L3.9 chondrites were performed for the presence of fullerene (C_60 in the meteorites. We calculated the concentration of C_60 in the acid residues by curvefitting the spectra with Gaussian functions. The upper limit of C_60 concentration in these meteorites appears to be less than an order of a few hundred ppm.

  20. Meteoritics, Number 19

    Science.gov (United States)

    1964-06-01

    266, 1958. 131. Houziaux, L., Spectres d’absorption infra-rouge de quelques verres naturels entr 2 et 24 microns (Infrared Absorption Spectra of...Taking Pb20L’ 1), Given as a Function of Time. reteorites was made in a work by M. M. Shats (Ref. 10). M. M. Shats de - termined the uranium and lead...billion years. Table 6. Age, l09 Type of Data of Published Meteorite Years Meteorite Source, Investi- gator Kashin 3.00 Chondrite 1951 (Ref. 14), E.K

  1. Asteroids, meteorites, and comets

    CERN Document Server

    Elkins-Tanton, Linda T

    2010-01-01

    Asteroids, Comets, and Meteorites provides students, researchers, and general readers with the most up-to-date information on this fascinating field. From the days of the dinosaurs to our modern environment, this book explores all aspects of these cosmic invaders.

  2. Search for fullerenes in stone meteorites

    Science.gov (United States)

    Oester, M. Y.; Kuechl, D.; Sipiera, P. P.; Welch, C. J.

    1994-07-01

    The possibility of identifying fullerenes in stony meteorites became apparent from a paper given by Radicati de Brozolo. In this paper it was reported that fullerenes were present in the debris resulting from a collision between a micrometeoroid and an orbiting satellite. This fact generated sufficient curiosity to initiate a search for the presence of fullerenes in various stone meteorites. In the present study seven ordinary chondrites (al-Ghanim L6 (find), Dimmitt H4 (find), Lazbuddie LL5 (find), New Concord H5 (fall), Silverton H4 (find), Springlake L6 (find), and Umbarger L3/6 (find)). Four carbonaceous chondrites (ALH 83100 C2 (find), ALH 83108 C30 (find), Allende CV3 (fall), and Murchison CM2 (fall), and one achondrite (Monticello How (find)) were analyzed for the presence of fullerenes. The analytical procedure employed was as follows: 100 mg of meteorite was ground up with a mortar and pestle; 10 mL of toluene was then added and the mixture was refluxed for 90 min; this mixture was then filtered through a short column of silica; a 50 microliter sample was then analyzed by high pressure liquid chromatography (HPLC) using a Buckyclutcher I column with a mobile phase consisting of equal volumes of toluene and hexane at a flow rate of 1.00 mg per minute, with detection at 330 and 600 nm. Three of the meteorites, Allende, Murchison, and al-Ghanim, gave HPLC traces containing peaks with similar retention times to the HPLC trace of an authentic fullerene C60. However, further analysis using an HPLC instrument equipped with a diode-array detector failed to confirm any of the substances detected in the three meteorites as C60. Additional analyses will be conducted to identify what the HPLC traces actually represent.

  3. Featured Image: Diamonds in a Meteorite

    Science.gov (United States)

    Kohler, Susanna

    2018-04-01

    This unique image which measures only 60 x 80 micrometers across reveals details in the Kapoeta meteorite, an 11-kg stone that fell in South Sudan in 1942. The sparkle in the image? A cluster of nanodiamonds discovered embedded in the stone in a recent study led by Yassir Abdu (University of Sharjah, United Arab Emirates). Abdu and collaborators showed that these nanodiamonds have similar spectral features to the interiors of dense interstellar clouds and they dont show any signs of shock features. This may suggest that the nanodiamonds were formed by condensation of nebular gases early in the history of the solar system. The diamonds were trapped in the surface material of the Kapoeta meteorites parent body, thought to be the asteroid Vesta. To read more about the authors study, check out the original article below.CitationYassir A. Abdu et al 2018 ApJL 856 L9. doi:10.3847/2041-8213/aab433

  4. Meteorites, atolls and whisky

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-06-15

    Improvements in the methods of measuring radioactive traces of elements in substances which can be hundreds of millions of years old have enabled many secrets of the remote past to be revealed. The techniques developed by nuclear scientists can also be applied to more recent times. In a symposium held in Monaco during March the discussions of radioactive dating and methods of low level counting brought references to meteorites, rocks, archaeology, coral atolls, ancient ceramics, and even whisky

  5. Characterization of insoluble organic matter in primitive meteorites by microRaman spectroscopy

    Science.gov (United States)

    Busemann, Henner; Alexander, M. O'd.; Nittler, Larry R.

    2007-08-01

    We have analyzed the chemically and isotopically well-characterized insoluble organic matter (IOM) extracted from 51 unequilibrated chondrites (8 CR, 9 CM, 1 CI, 3 ungrouped C, 9 CO, 9 CV, 10 ordinary, 1 CB and 1 E chondrites) using confocal imaging Raman spectroscopy. The average Raman properties of the IOM, as parameterized by the peak characteristics of the so-called D and G bands, which originate from aromatic C rings, show systematic trends that are correlated with meteorite (sub-) classification and IOM chemical compositions. Processes that affect the Raman and chemical properties of the IOM, such as thermal metamorphism experienced on the parent bodies, terrestrial weathering and amorphization due to irradiation in space, have been identified. We established separate sequences of metamorphism for ordinary, CO, oxidized, and reduced CV chondrites. Several spectra from the most primitive chondrites reveal the presence of organic matter that has been amorphized. This amorphization, usually the result of sputtering processes or UV or particle irradiation, could have occurred during the formation of the organic material in interstellar or protoplanetary ices or, less likely, on the surface of the parent bodies or during the transport of the meteorites to Earth. D band widths and peak metamorphic temperatures are strongly correlated, allowing for a straightforward estimation of these temperatures.

  6. Parenting

    Science.gov (United States)

    ... parents, people are always ready to offer advice. Parenting tips, parents' survival guides, dos, don'ts, shoulds ... right" way to be a good parent. Good parenting includes Keeping your child safe Showing affection and ...

  7. Forging Asteroid-Meteorite Relationships Through Reflectance Spectroscopy

    Science.gov (United States)

    Burbine, T. H.; Binzel, R. P.; Bus, S. J.; Buchanan, P. C.; Hinrichs, J. L.; Meibom, A.; Hiroi, T.; Sunshine, J. M.

    2000-01-01

    Near-infrared spectra were obtained for 196 asteroids as part of SMASSIR. SMASSIR focused on observing asteroids assumed to be one of the following: (1) olivine-rich, (2) objects with "Vesta-like spectra" (the "Vestoids"), and (3) postulated meteorite parent bodies.

  8. Moessbauer spectroscopy of the Soledade meteorite

    International Nuclear Information System (INIS)

    Paduani, Clederson; Peres, Carlos Ariel Samudio

    2004-01-01

    Full text: Since the early studies of the microstructure and chemical composition of meteorites the formation of magnetic phases have attracted the attention of metallurgists. Mostly metallic specimens presented high contents of nickel and iron as major constituents, and thus the Fe-Ni alloys formed under such special conditions have been the subject of several investigations with a variety of experimental techniques. This is not an easy task considering the weathering process and the distribution of oxides in the metallic matrix, which in some cases varies in composition from one region to another. In this work we applied the Moessbauer spectroscopy to study the iron-bearing phases detected in the meteorite called Soledade. Although no one knows precisely who and when this specimen was found, it received the name of the locality from where it proceeded near the city of Passo Fundo in the state of Rio Grande do Sul in Brazil. The first studies indicate that this metallic meteorite is an octahedrite, with polycrystalline troilite, cohenite, schreibersite and rhabdites as major constituents. It consists of a solid block weighing 68 kg, with an irregular form measuring about 36x22x16 cm. (author)

  9. Study of Meteoritic Inclusion

    DEFF Research Database (Denmark)

    Olsen, Mia Bjørg Stolberg

    of meteorite samples that date back to the birth of the solar system. In this thesis, we have taken advantage of novel methods for the high-precision analysis of various radiogenic and stable isotope systems by plasma source and thermal ionization mass spectrometry (ICPMS and TIMS) as well as by secondary....... The manuscripts presented in this thesis have provided critical insights into the origin and distribution of short-lived radioisotopes as well as the formation and transport history of chondrules and, by extension, the precursor material to asteroidal and planetary bodies. The proposal of 26Al heterogeneity...

  10. Presolar Diamond in Meteorites

    OpenAIRE

    Amari, Sachiko

    2009-01-01

    Presolar diamond, the carrier of the isotopically anomalous Xe component Xe-HL, was the first mineral type of presolar dust that was isolated from meteorites. The excesses in the light, p-process only isotopes 124Xe and 126Xe, and in the heavy, r-process only isotopes 134Xe and 136Xe relative to the solar ratios indicate that Xe-HL was produced in supernovae: they are the only stellar source where these two processes are believed to take place. Although these processes occur in supernovae, th...

  11. Titanium isotopic anomalies in meteorites

    International Nuclear Information System (INIS)

    Niemeyer, S.; Lugmair, G.W.

    1984-01-01

    High-precision analyses of Ti are reported for samples from a variety of meteorite classes. The expanded data base for Allende inclusions still shows Ti isotope anomalies in every inclusion. All the coarse-grained inclusions give quite similar patterns, but fine-grained inclusions show more variable, and sometimes larger, anomalies. One inclusion, 3675A, was analyzed because others identified it as a possible 'FUN' inclusion due to its mass-fractionated Mg. This designation is supported by the significantly more complex Ti isotopic pattern for 3675A compared to all our other Allende inclusions. Available data fail to suggest that any particular Allende mineral phase, including a chromite-carbon fraction from an acid residue, is especially rich in anomalous Ti. We also find anomalous Ti in a bulk sample of a C1 chondrite and in matrix separates from C2 chondrites. The excesses of 50 Ti are smaller than for Allende inclusions, and subtle differences in Ti isotopic patterns tentatively suggest that parent materials for C1-C2 matrix and Allende inclusions are not directly related. Analyses of chondrules from unequilibrated ordinary chondrites did not yield clear evidence for anomalous Ti, but some 'larger than usual' deficits at 50/46 give encouragement for future work in this direction. (author)

  12. Meteorites for K-12 Classrooms: NASA Meteorite Educational Materials

    Science.gov (United States)

    Lindstrom, M.; Allen, J.

    1995-09-01

    The fall of a new meteorite is an event that catches the interest of the public in matters of science. The threat of a huge impact like last year's comet Shoemaker-Levy 9 gives us all reason to evaluate such potential risks. NASA's meteorite educational materials use our natural interest in rocks from space to present classroom activities on planetary science. The meteorite educational package includes a meteorite sample disk, a teachers's guide and a slide set. The sample disk is a lucite disk containing chips of six different kinds of meteorites (3 chondrites, achondrite, iron, stony-iron). EXPLORING METEORITE MYSTERIES is a teacher's guide with background information and 19 hands-on or heads-on activities for grades 4-12. It was prepared in a partnership of planetary scientists and teachers. The slide set consists of 48 slides with captions to be used with the activities. The materials will be available in Fall 1995. Teachers may obtain a loan of the whole package from NASA Teacher Resource Centers; researchers may borrow them from the JSC meteorite curator. The booklet is available separately from the same sources, and the slide set will be available from NASA CORE. EXPLORING METEORITE MYSTERIES is an interdisciplinary planetary science unit which teaches basic science concepts and techniques together with math, reading, writing and social studies The activities are done in a variety of different teaching styles which emphasize observation, experimentation and critical thinking. The activities are ideal for middle schools where teaming makes interdisciplinary units desireable, but most of the activities can be easily modified for grade levels from upper elementary through high school. Meteorites are a natural subject for interdisciplinary teaching because their study involves all fields of science and offers fascinating historical accounts and possibilities for creative expression. Topics covered in EXPLORING METEORITE MYSTERES are centered around basic

  13. Spectroscopic investigation of the Dergaon meteorite with reference ...

    Indian Academy of Sciences (India)

    Analysis of a part of the meteorite which fell at Dergaon (India) on March 2, 16.40 local time (2001) is presented with the help of FTIR, absorption and atomic spectra. The FTIR spectrum exhibits prominent absorption bands in the region 800–1100 cm-1, originating from the valence vibration of SiO4, a basic component of the ...

  14. On presolar meteoritic sulphides

    International Nuclear Information System (INIS)

    Clayton, D.D.; Ramadurai, S.

    1977-01-01

    It is stated that discoveries of isotopic anomalies in meteorites caused some workers to postulate nucleosynthetic inhomogeneities that were somehow carried into the early solar system. A picture was developed treating most anomalies as extinct radioactivities trapped in mineral condensations in the expanding sites of explosive nucleosynthesis, such as supernovae or novae. As evidence for this grows it becomes clear that not only isotopic but also mineralogical evidence of presolar grains is wanted, and also knowledge of what supernovae condensates are likely to survive. It is suggested here that a search should be made among sulphides in meteorites, searching especially for sulphides of Ti. The reasoning is that many sulphides, especially Ti sulphides, will not be expected in solar condensation sequences, but are expected to dominate certain key zones of supernovae expansion. Sulphur seems to have resulted primarily from the nuclear explosions of O and Si, and arguments leading to that conclusion are analysed. It is thought that the discussion could lead to important discoveries for nucleosynthesis and the origin of the solar system. (U.K.)

  15. The Orgueil meteorite: 150 years of history

    Science.gov (United States)

    Gounelle, Matthieu; Zolensky, Michael E.

    2014-10-01

    The goal of this paper is to summarize 150 yr of history of a very special meteorite. The Orgueil meteorite fell near Montauban in southwestern France on May 14, 1864. The bolide, which was the size of the full Moon, was seen across Western France, and almost immediately made the news in local and Parisian newspapers. Within a few weeks of the fall, a great diversity of analyses were performed under the authority of Gabriel Auguste Daubrée, geology professor at the Paris Museum, and published in the Comptes Rendus de l'Académie des Sciences. The skilled scientists reported the presence of iron sulfides, hydrated silicates, and carbonates in Orgueil. They also characterized ammonium salts which are now gone, and observed sulfates being remobilized at the surface of the stone. They identified the high water and carbon contents, and noted similarities with the Alais meteorite, which had fallen in 1806, 300 km away. While Daubrée and his colleagues noted the similarity of the Orgueil organic matter with some terrestrial humus, they were cautious not to make a direct link with living organisms. One century later, Nagy and Claus were less prudent and announced the discovery of "organized" elements in some samples of Orgueil. Their observations were quickly discredited by Edward Anders and others who also discovered that some pollen grains were intentionally placed into the rock back in the 1860s. Orgueil is now one of the most studied meteorites, indeed one of the most studied rocks of any kind. Not only does it contain a large diversity of carbon-rich compounds, which help address the question of organo-synthesis in the early solar system but its chemical composition is also close to that of the Sun's photosphere and serves as a cosmic reference. Secondary minerals, which make up 99% of the volume of Orgueil, were probably formed during hydrothermal alteration on the parent-body within the first few million years of the solar system; their study is essential to our

  16. Antarctic Meteorite Newsletter. Volume 22

    Science.gov (United States)

    Satterwhite, Cecilia (Editor); Lindstrom, Marilyn (Editor)

    1999-01-01

    This Newsletter Contains Classifications of 143 New Meteorites from the 1997 ANSMET Collection. Descriptions are given for 6 meteorites;2 eucrites, and 4 ordinary chondrites. We don't expect much excitement from the rest of the 1997 collection. JSC has examined another 100 meteorites to send to the Smithsonian for classification and they appear to be more of the same LL5 shower. However, past experience tells us that there will be some treasures hidden in the remaining samples. Hope rings eternal, but we can't wait to see the 1998 collection described below.

  17. Spectral analysis of meteorites ablated in a wind tunnel

    Science.gov (United States)

    Drouard, A.; Vernazza, P.; Loehle, S.; Gattacceca, J.; Zander, T.; Eberhart, M.; Meindl, A.; Oefele, R.; Vaubaillon, J.; Colas, F.

    2017-09-01

    Recently and for the very first time, experiments simulating vaporization of a meteorite sample were performed in a wind tunnel near Stuttgart with the specific aim to record emission spectra of the vaporized material. Using a high enthalpy air plasma flow for modeling an equivalent air friction of an entry speed of about 10 km/s, three meteorite types (H, CM and HED) and two meteoritical analogues (basalt and argillite) were ablated and high resolution spectra were recorded simultaneously. After the identification of all atomic lines, we per- formed a detailed study of our spectra using two approaches: (i) by direct comparison of multiplet in- tensities between the samples and (ii) by computation of a synthetic spectrum to constrain some physical parameters (temperature, elemental abundance). Finally, we compared our results to the elemental composition of our samples and we determined how much compositional information can be retrieved for a given meteor using visible sectroscopy.

  18. Fungal Peptaibiotics: Assessing Potential Meteoritic Amino Acid Contamination

    Science.gov (United States)

    Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.; Bruckner, H.

    2010-01-01

    The presence of non-protein alpha-dialkyl-amino acids such as alpha-aminoisobutyric acid (alpha-A1B) and isovaline (Iva), which are relatively rare in the terrestrial biosphere, has long been used as an indication of the indigeneity of meteoritic amino acids, however, the discovery of alpha-AIB in peptides producers by a widespread group of filamentous fungi indicates the possibility of a terrestrial biotic source for the alpha-AIB observed in some meteorites. The alpha-AIB-containing peptides produced by these fungi are dubbed peptaibiotics. We measured the molecular distribution and stable carbon and nitrogen isotopic ratios for amino acids found in the total hydrolysates of four biologically synthesized peptaibiotics. We compared these aneasurenetts with those from the CM2 carbonaceous chondrite Murchison and from three Antarctic CR2 carbonaceous chondrites in order to understand the peptaibiotics as a potential source of meteoritic contamination.

  19. Study of Meteoritic Inclusion

    DEFF Research Database (Denmark)

    Olsen, Mia Bjørg Stolberg

    by small, potentially terrestrial-like planets. Given the tantalizing perspective of discovering an Earth-like world, understanding the sequence of events leading to the formation our solar system and planetary bodies has never been so relevant. Theoretical and computational astrophysics as well...... of meteorite samples that date back to the birth of the solar system. In this thesis, we have taken advantage of novel methods for the high-precision analysis of various radiogenic and stable isotope systems by plasma source and thermal ionization mass spectrometry (ICPMS and TIMS) as well as by secondary....... The manuscripts presented in this thesis have provided critical insights into the origin and distribution of short-lived radioisotopes as well as the formation and transport history of chondrules and, by extension, the precursor material to asteroidal and planetary bodies. The proposal of 26Al heterogeneity...

  20. LEW 88516: A Meteorite Compositionally Close to the "Martian Mantle"

    Science.gov (United States)

    Dreibus, G.; Jochum, K. H.; Palme, H.; Spettel, B.; Wlotzka, F.; Wanke, H.

    1992-07-01

    Several samples from a total of 250 mg of the recently discovered Antarctic shergottite LEW 88516 were analysed for major and trace elements by neutron activation techniques, SSMS, and a carbon-sulfur analyser. Results are presented in Table 1, together with data on ALHA 77005 (Wanke et al., 1976). This and earlier results (Boynton et al., 1992; Lindstrom et al.,1992) show the close compositional similarity of Lew 88516 to ALHA 77005. A major difference between the two shergottites is the much lower iodine content of the ALHA 77005 meteorite. The absence of similar variations in Br and Cl confirms earlier suggestions of an Antarctic source for the I excess. In a Mg/Si vs. Al/Si diagram (Fig. 1) the LEW 88516 meteorite plots at the intersection of a Shergotty parent (SPB) body fractionation trend and a line connecting enstatite chondrites and CM chondrites. The position of LEW 88516 and also of ALHA 77005 in the vicinity of ordinary chondrites is indicative of their relatively primitive composition. Lithophile trace elements show some enhancement of Sc and V over heavy REE and depletion of light REE, suggesting either a residual character for the two meteorites or assimilation of a cumulate phase during their formation. Comparatively high Ni and Co also reflect the more mafic character of the two meteorites. The present analysis and the earlier data on ALHA 77005 unambiguously demonstrate the presence of Ir in an abundance range typical for the terrestrial upper mantle. A similar Ir level was found in Chassigny, but the more fractionated Shergotty has 100 times lower Ir contents. The presence of Ir in the martian mantle samples may be the result of sulfide-silicate equilibration. The sulfides in Lew 88516 are small pyrrhotite grains (5-30 micron, 52 atom% S) and occur often together with ilmenite, at grain boundaries of the major silicate minerals. Sulfides contain an average of 1.8% Ni. However, the major fraction of Ni must reside in oxides and/or silicates as the

  1. Mineralogy and Textural Characteristics of Fine-grained Rims in the Yamato 791198 CM2 Carbonaceous Chondrite: Constraints on the Location of Aqueous Alteration

    Science.gov (United States)

    Chizmadia, Lysa J.; Brearley, Adrian J.

    2003-01-01

    Carbonaceous chondrites provide important clues into the nature of physical and chemical processes in the early solar system. A question of key importance concerns the role of water in solar nebular and asteroidal processes. The effects of water on primary mineral assemblages have been widely recognized in chondritic meteorites, especially the CI and CM carbonaceous chondrites. These meteorites have undergone extensive aqueous alteration that occurred prior to their arrival on Earth. In the case of the CM chondrites, this alteration has resulted in the partial to complete replacement of the primary nebular phases with secondary alteration phases. Considerable controversy exists as to the exact location where the alteration of the CM chondrites occurred. Several textural lines of evidence have been cited in support of aqueous alteration prior to the accretion of the final parent asteroid. An important line of evidence to support this hypothesis is the dis-equilibrium nature of fine-grained rims and matrix materials. [2] also noted the juxtaposition of micron-sized Fe-Ni metal grains and apparently unaltered chondrule glass against hydrated rim silicates. Conversely, there is a large body of evidence in favor of parent body alteration such as the occurrence of undisturbed Fe-rich aureoles and the systematic redistribution of elemental components over millimeters, e.g., Mg(+2) into the matrix and Fe(+2) into chondrules etc.

  2. The Virtual Museum for Meteorites

    Science.gov (United States)

    Madiedo, J. M.

    2012-09-01

    Meteorites play a fundamental role in education and outreach, as these samples of extraterrestrial materials are very valuable tools to promote the public's interest in Astronomy and Planetary Sciences. Thus, for instance, meteorite exhibitions reveal the interest and fascination of students, educators and even researchers for these peculiar rocks and how these can provide information to explain many fundamental questions related to the origin and evolution of our Solar System. However, despite the efforts of private collectors, museums and other institutions to organize meteorite exhibitions, the reach of these is usually limited. But this issue can be addressed thanks to new technologies related to the Internet. In fact we can take advantage of HTML and related technologies to overcome local boundaries and open the possibility of offering these exhibitions for a global audience. With this aim a Virtual Museum for Meteorites has been created and a description of this web-based tool is given here.

  3. Aqueous Alteration of Carbonaceous Chondrites: New Insights from Comparative Studies of Two Unbrecciated CM2 Chondrites, Y 791198 and ALH 81002

    Science.gov (United States)

    Chizmadia, L. J.; Brearley, A. J.

    2004-01-01

    Carbonaceous chondrites are an important resource for understanding the physical and chemical conditions in the early solar system. In particular, a long-standing question concerns the role of water in the cosmochemical evolution of carbonaceous chondrites. It is well established that extensive hydration of primary nebular phases occurred in the CM and CI chondrites, but the location where this alteration occurred remains controversial. In the CM2 chondrites, hydration formed secondary phases such as serpentine, tochilinite, pentlandite, carbonate and PCP. There are several textural observations which suggest that alteration occurred before the accretion of the final CM parent asteroid, i.e. preaccretionary alteration. Conversely, there is a significant body of evidence that supports parent-body alteration. In order to test these two competing hypotheses further, we studied two CM chondrites, Y-791198 and ALH81002, two meteorites that exhibit widely differing degrees of aqueous alteration. In addition, both meteorites have primary accretionary textures, i.e. experienced minimal asteroidal brecciation. Brecciation significantly complicates the task of unraveling alteration histories, mixing components that have been altered to different degrees from different locations on the same asteroidal parent body. Alteration in Y-791198 is mostly confined to chondrule mesostases, FeNi metal and fine-grained matrix and rims. In comparison, the primary chondrule silicates in ALH81002 have undergone extensive replacement by secondary hydrous phases. This study focuses on compositional and textural relationships between chondrule mesostasis and the associated rim materials. Our hypothesis is: both these components are highly susceptible to aqueous alteration and should be sensitive recorders of the alteration process. For parent body alteration, we expect systematic coupled mineralogical and compositional changes in rims and altered mesostasis, as elemental exchange between these

  4. Coordinated In Situ Analyses of Organic Nanoglobules in the Sutter's Mill Meteorite

    Science.gov (United States)

    Nakamura--Messenger, K.; Messenger, S.; Keller, L. P.; Clemett, S. J.; Nguyen, A. N.; Gibson, E. K.

    2013-01-01

    The Sutter s Mill meteorite is a newly fallen carbonaceous chondrite that was collected and curated quickly after its fall [1]. Preliminary petrographic and isotopic investigations suggest affinities to the CM2 carbonaceous chondrites. The primitive nature of this meteorite and its rapid recovery provide an opportunity to investigate primordial solar system organic matter in a unique new sample. Organic matter in primitive meteorites and chondritic porous interplanetary dust particles (CP IDPs) is commonly enriched in D/H and N-15/N-14 relative to terrestrial values [2-4]. These anomalies are ascribed to the partial preservation of presolar cold molecular cloud material [2]. Some meteorites and IDPs contain gm-size inclusions with extreme H and N isotopic anomalies [3-5], possibly due to preserved primordial organic grains. The abundance and isotopic composition of C in Sutter's Mill were found to be similar to the Tagish Lake meteorite [6]. In the Tagish Lake meteorite, the principle carriers of large H and N isotopic anomalies are sub-micron hollow organic spherules known as organic nanoglobules [7]. Organic nanoglobules are commonly distributed among primitive meteorites [8, 9] and cometary samples [10]. Here we report in-situ analyses of organic nano-globules in the Sutter's Mill meteorite using UV fluorescence imaging, Fourier-transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (STEM), NanoSIMS, and ultrafast two-step laser mass spectrometry (ultra-L2MS).

  5. Mineralogical, crystallographic and redox features of the earliest stages of fluid alteration in CM chondrites

    Science.gov (United States)

    Pignatelli, Isabella; Marrocchi, Yves; Mugnaioli, Enrico; Bourdelle, Franck; Gounelle, Matthieu

    2017-07-01

    The CM chondrites represent the largest group of hydrated meteorites and span a wide range of conditions, from less altered (i.e., CM2) down to heavily altered (i.e., CM1). The Paris chondrite is considered the least altered CM and thus enables the earliest stages of aqueous alteration processes to be deciphered. Here, we report results from a nanoscale study of tochilinite/cronstedtite intergrowths (TCIs) in Paris-TCIs being the emblematic secondary mineral assemblages of CM chondrites, formed from the alteration of Fe-Ni metal beads (type-I TCIs) and anhydrous silicates (type-II TCIs). We combined high-resolution transmission electron microscopy, scanning transmission X-ray microscopy and electron diffraction tomography to characterize the crystal structure, crystal chemistry and redox state of TCIs. The data obtained are useful to reconstruct the alteration conditions of Paris and to compare them with those of other meteorites. Our results show that tochilinite in Paris is characterized by a high hydroxide layer content (n = 2.1-2.2) regardless of the silicate precursors. When examined alongside other CMs, it appears that the hydroxide layer and iron contents of tochilinites correlate with the degree of alteration experienced by the chondrites. The Fe3+/ΣFe ratios of TCIs are high: 8-15% in tochilinite, 33-60% in cronstedtite and 70-80% in hydroxides. These observations suggest that alteration of CM chondrites took place under oxidizing conditions that could have been induced by significant H2 release during serpentinization. Similar results were recently reported in CR chondrites (Le Guillou et al., 2015), suggesting that the process(es) controlling the redox state of the secondary mineral assemblages were quite similar in the CM and CR parent bodies despite the different alteration conditions. According to our mineralogical and crystallographic survey, the formation of TCIs in Paris occurred at temperatures lower than 100 °C, under neutral, slightly alkaline

  6. On the Behavior of Phosphorus During the Aqueous Alteration of CM2 Carbonaceous Chondrites

    Science.gov (United States)

    Brearley, Adrian J.; Chizmadia, Lysa J.

    2005-01-01

    During the earliest period of solar system formation, water played an important role in the evolution of primitive dust, both after accretion of planetesimals and possible before accretion within the protoplanetary disk. Many chondrites show evidence of variable degrees of aqueous alteration, the CM2 chondrites being among the most studied [1]. This group of chondrites is characterized by mineral assemblages of both primary and secondary alteration phases. Hence, these meteorites retain a particularly important record of the reactions that occurred between primary high temperature nebular phases and water. Studies of these chondrites can provide information on the conditions and environments of aqueous alteration and the mobility of elements during alteration. This latter question is at the core of a debate concerning the location of aqueous alteration, i.e. whether alteration occurred predominantly within a closed system after accretion (parent body alteration) or whether some degree of alteration occurred within the solar nebula or on ephemeral protoplanetary bodies prior to accretion. At the core of the parent body alteration model is the hypothesis that elemental exchange between different components, principally chondrules and matrix, must have occurred. chondrules and matrix, must have occurred. In this study, we focus on the behavior of the minor element, phosphorus. This study was stimulated by observations of the behavior of P during the earliest stages of alteration in glassy mesostasis in type II chondrules in CR chondrites and extends the preliminary observations of on Y791198 to other CM chondrites.

  7. Antarctic Meteorite Classification and Petrographic Database

    Science.gov (United States)

    Todd, Nancy S.; Satterwhite, C. E.; Righter, Kevin

    2011-01-01

    The Antarctic Meteorite collection, which is comprised of over 18,700 meteorites, is one of the largest collections of meteorites in the world. These meteorites have been collected since the late 1970's as part of a three-agency agreement between NASA, the National Science Foundation, and the Smithsonian Institution [1]. Samples collected each season are analyzed at NASA s Meteorite Lab and the Smithsonian Institution and results are published twice a year in the Antarctic Meteorite Newsletter, which has been in publication since 1978. Each newsletter lists the samples collected and processed and provides more in-depth details on selected samples of importance to the scientific community. Data about these meteorites is also published on the NASA Curation website [2] and made available through the Meteorite Classification Database allowing scientists to search by a variety of parameters

  8. Antarctic Martian Meteorites at Johnson Space Center

    Science.gov (United States)

    Funk, R. C.; Satterwhite, C. E.; Righter, K.; Harrington, R.

    2018-01-01

    This past year marked the 40th anniversary of the first Martian meteorite found in Antarctica by the ANSMET Antarctic Search for Meteorites) program, ALH 77005. Since then, an additional 14 Martian meteorites have been found by the ANSMET program making for a total of 15 Martian meteorites in the U. S. Antarctic meteorite collection at Johnson Space Center (JSC). Of the 15 meteorites, some have been paired so the 15 meteorites actually represent a total of approximately 9 separate samples. The first Martian meteorite found by ANSMET was ALH 77005 (482.500 g), a lherzolitic shergottite. When collected, this meteorite was split as a part of the joint expedition with the National Institute of Polar Research (NIPR) Japan. Originally classified as an "achondrite-unique", it was re-classified as a Martian lherzolitic shergottite in 1982. This meteorite has been allocated to 137 scientists for research and there are 180.934 g remaining at JSC. Two years later, one of the most significant Martian meteorites of the collection at JSC was found at Elephant Moraine, EET 79001 (7942.000 g), a shergottite. This meteorite is the largest in the Martian collection at JSC and was the largest stony meteorite sample collected during the 1979 season. In addition to its size, this meteorite is of particular interest because it contains a linear contact separating two different igneous lithologies, basaltic and olivine-phyric. EET 79001 has glass inclusions that contain noble gas and nitrogen compositions that are proportionally identical to the Martian atmosphere, as measured by the Viking spacecraft. This discovery helped scientists to identify where the "SNC" meteorite suite had originated, and that we actually possessed Martian samples. This meteorite has been allocated to 205 scientists for research and 5,298.435 g of sample is available.

  9. Galactic cosmic-ray-produced radionuclides in Antarctic meteorites and a lunar core

    International Nuclear Information System (INIS)

    Fox, R.L.

    1987-01-01

    Radionuclide depth effects in a meteorite, the history and pairing of Antarctic meteorites and processes on the lunar surface are discussed in six chapters. A depth profile of 26 Al, 10 Be and 53 Mn activities have been measured in eleven metal phase samples of the Antarctic meteorite ALHA78084 to determine the importance of the secondary cascade in producing these nuclides in a 30 centimeter diameter meteorite. The results show a buildup of lower energy reaction products and a flat profile for high energy reaction products with depth. The activity of 53 Mn has been measured as a function of depth in eleven soil samples from the lunar double drive tubes 15011/15010. The results agree within error with the previous results of Nishiizumi. These data are consistent with the previously published 26 Al results of the Battelle Northwest group which indicated a disturbed profile down to 17 g/cm 2 and an accumulation rate of 2 cm/My. Comparison with the gardening models of Arnold and Langevin and the local topography suggests such a continuous accumulation is the result of steady downslope transport of surface soil for 7 to 10 My at this site. The 53 Mn activity was determined in eleven samples in eight Allan Hills-80 Antarctic meteorites and one sample from an Elephant Moraine Antarctic meteorite. Mineralogic and field relation data suggest that Allan Hills meteorites to be two sets of paired falls. The 53 Mn results are consistent with the grouping of these meteorites as paired falls excluding the meteorite ALHA80127. comparison with future nuclear particle track work and results from the measurement of other cosmogenic nuclides will provide more definitive results

  10. Elemental and isotope behavior of macromolecular organic matter from CM chondrites during hydrous pyrolysis

    Science.gov (United States)

    Oba, Y.; Naraoka, H.

    2009-08-01

    A new insight into carbon and hydrogen isotope variations of insoluble organic matter (IOM) is provided from seven CM chondrites, including Murchison and six Antarctic meteorites (Y-791198, Y-793321, A-881280, A-881334, A-881458 and B-7904) as well as Murchison IOM residues after hydrous pyrolysis at 270-330 °C for 72 h. Isotopic compositions of bulk carbon (δ13Cbulk) and hydrogen (δD) of the seven IOMs vary widely, ranging from -15.1 to -7.6‰ and +133 to +986‰, respectively. Intramolecular carboxyl carbon (δ13CCOOH) is more enriched in 13C by 7.5 -11‰ than bulk carbon. After hydrous pyrolysis of Murchison IOM at 330 °C, H/C ratio, δ13Cbulk, δ13CCOOH, and δD values decrease by up to 0.31, 3.5‰, 5.5‰, and 961‰, respectively. The O/C ratio increases from 0.22 to 0.46 at 270 °C and to 0.25 at 300 °C, and decreases to 0.10 at 330 °C. δ13Cbulk- δD cross plot of Murchison IOM and its pyrolysis residues shows an isotopic sequence. Of the six Antarctic IOMs, A-881280, A-881458, Y-791198 and B-7904 lie on or near the isotopic sequence depending on the degree of hydrous and/or thermal alteration, while A-881334 and Y-793321 consist of another distinct isotope group. A δ13Cbulk-δ13CCOOH cross-plot of IOMs, including Murchison pyrolysis residues, has a positive correlation between them, implying that the oxidation process to produce carboxyls is similar among all IOMs. These isotope distributions reflect various degree of alteration on the meteorite parent bodies and/or difference in original isotopic compositions before the parent body processes.

  11. Early planetesimal melting from an age of 4.5662 Gyr for differentiated meteorites

    DEFF Research Database (Denmark)

    Baker, J.; Bizzarro, Martin; Wittig, N.

    2005-01-01

    for these meteorites, however, are typically younger than age constraints for planetesimal differentiation. Such young ages indicate that the energy required to melt their parent bodies could not have come from the most likely heat source-radioactive decay of short-lived nuclides (Al and Fe) injected from a nearby...... decay could have triggered planetesimal melting. Small Mg excesses in bulk angrite samples confirm that Al decay contributed to the melting of their parent body. These results indicate that the accretion of differentiated planetesimals pre-dated that of undifferentiated planetesimals, and reveals......Long- and short-lived radioactive isotopes and their daughter products in meteorites are chronometers that can test models for Solar System formation. Differentiated meteorites come from parent bodies that were once molten and separated into metal cores and silicate mantles. Mineral ages...

  12. U-Pb Dating of Zircons and Phosphates in Lunar Meteorites, Acapulcoites and Angrites

    Science.gov (United States)

    Zhou, Q.; Zeigler, R. A.; Yin, Q. Z.; Korotev, R. L.; Joliff, B. L.; Amelin, Y.; Marti, K.; Wu, F. Y.; Li, X. H.; Li, Q. L.; hide

    2012-01-01

    Zircon U-Pb geochronology has made a great contribution to the timing of magmatism in the early Solar System [1-3]. Ca phosphates are another group of common accessory minerals in meteorites with great potential for U-Pb geochronology. Compared to zircons, the lower closure temperatures of the U-Pb system for apatite and merrillite (the most common phosphates in achondrites) makes them susceptible to resetting during thermal metamorphism. The different closure temperatures of the U-Pb system for zircon and apatite provide us an opportunity to discover the evolutionary history of meteoritic parent bodies, such as the crystallization ages of magmatism, as well as later impact events and thermal metamorphism. We have developed techniques using the Cameca IMS-1280 ion microprobe to date both zircon and phosphate grains in meteorites. Here we report U-Pb dating results for zircons and phosphates from lunar meteorites Dhofar 1442 and SaU 169. To test and verify the reliability of the newly developed phosphate dating technique, two additional meteorites, Acapulco, obtained from Acapulco consortium, and angrite NWA 4590 were also selected for this study as both have precisely known phosphate U-Pb ages by TIMS [4,5]. Both meteorites are from very fast cooled parent bodies with no sign of resetting [4,5], satisfying a necessity for precise dating.

  13. HYDROGEN CYANIDE IN THE MURCHISON METEORITE

    Energy Technology Data Exchange (ETDEWEB)

    Pizzarello, Sandra, E-mail: pizzar@asu.edu [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85018-1604 (United States)

    2012-08-01

    Carbonaceous chondrites are meteorites that may contain abundant organic materials, including soluble compounds as diverse as amino acids and hydrocarbons. We report here the finding of hydrogen cyanide in the Murchison meteorite in amounts {<=} 10 ppm. HCN was never searched for in meteorites and its detection in sizeable amount is surprising in view of the extensive water phase that is recorded by the petrology of this type of meteorites and could have exhausted their HCN content through multiple reactions. The finding adds to the inventory of simple volatile molecules found in both comets and meteorites.

  14. Mysterious iodine-overabundance in Antarctic meteorites

    Science.gov (United States)

    Dreibus, G.; Waenke, H.; Schultz, L.

    1986-01-01

    Halogen as well as other trace element concentrations in meteorite finds can be influenced by alteration processes on the Earth's surface. The discovery of Antarctic meteorites offered the opportunity to study meteorites which were kept in one of the most sterile environment of the Earth. Halogen determination in Antartic meteorites was compared with non-Antarctic meteorites. No correlation was found between iodine concentration and the weathering index, or terrestrial age. The halogen measurements indicate a contaminating phase rich in iodine and also containing chlorine. Possible sources for this contamination are discussed.

  15. Mysterious iodine-overabundance in Antarctic meteorites

    International Nuclear Information System (INIS)

    Dreibus, G.; Waenke, H.; Schultz, L.

    1986-01-01

    Halogen as well as other trace element concentrations in meteorite finds can be influenced by alteration processes on the Earth's surface. The discovery of Antarctic meteorites offered the opportunity to study meteorites which were kept in one of the most sterile environment of the Earth. Halogen determination in Antartic meteorites was compared with non-Antarctic meteorites. No correlation was found between iodine concentration and the weathering index, or terrestrial age. The halogen measurements indicate a contaminating phase rich in iodine and also containing chlorine. Possible sources for this contamination are discussed

  16. Investigation of carbonates in the Sutter's Mill meteorite grains with hyperspectral infrared imaging micro-spectroscopy

    Science.gov (United States)

    Yesiltas, Mehmet

    2018-04-01

    Synchrotron-based high spatial resolution hyperspectral infrared imaging technique provides thousands of infrared spectra with high resolution, thus allowing us to acquire detailed spatial maps of chemical molecular structures for many grains in short times. Utilizing this technique, thousands of infrared spectra were analyzed at once instead of inspecting each spectrum separately. Sutter's Mill meteorite is a unique carbonaceous type meteorite with highly heterogeneous chemical composition. Multiple grains from the Sutter's Mill meteorite have been studied using this technique and the presence of both hydrous and anhydrous silicate minerals have been observed. It is observed that the carbonate mineralogy varies from simple to more complex carbonates even within a few microns in the meteorite grains. These variations, the type and distribution of calcite-like vs. dolomite-like carbonates are presented by means of hyperspectral FTIR imaging spectroscopy with high resolution. Various scenarios for the formation of different carbonate compositions in the Sutter's Mill parent body are discussed.

  17. Identification, testing, and analysis of a meteorite debris from jhelum, pakistan

    International Nuclear Information System (INIS)

    Kayani, S.

    2012-01-01

    In this research paper, X-ray diffraction (XRD) and X-ray fluorescence (XRF) spectrometry have been used to determine the mineralogical and elemental composition of a stone sample recovered from a location near village Lehri in district Jhelurn, Pakistan. The test data is compared with previous findings (as reported in literature and included in references) to identify this sample stone as part of a prehistoric meteorite ablation debris. Carbon content of a specimen of the meteorite debris has also been determined through combustion analysis. This carbon abundance has been compared with carbon wt% value of a certain type of meteorites to establ ish the origin and nature of the parent body of this particular meteorite debris. (author)

  18. Moessbauer study of Slovak meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Lipka, J.; Sitek, J.; Dekan, J., E-mail: julius.dekan@stuba.sk; Degmova, J. [Slovak University of Technology, Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology (Slovakia); Porubcan, V. [Comenius University, Faculty of Mathematics and Physics (Slovakia)

    2013-04-15

    {sup 57}Fe Moessbauer spectroscopy was used as an analytical tool in the investigation of iron containing compounds of two meteorites (Rumanova and Kosice) out of total of six which had fallen on Slovak territory. In the magnetic fraction of the iron bearing compounds in the Rumanova meteorite, maghemite, troilite and Fe-Ni alloy were identified. In the non-magnetic fraction silicate phases were found, such as olivine and pyroxene. The paramagnetic component containing Fe{sup 3 + } ions corresponds probably to small superparamagnetic particles. The Kosice meteorite was found near the town of Kosice in February 2010. Its magnetic fraction consists of a Fe-Ni alloy with the Moessbauer parameters of the magnetic field corresponding to kamacite {alpha}-Fe(Ni, Co) and troilite. The non-magnetic part consists of Fe{sup 2 + } phases such as olivine and pyroxene and traces of a Fe{sup 3 + } phase. The main difference between these meteorites is their iron oxide content. These kinds of analyses can bring important knowledge about phases and compounds formed in extraterrestrial conditions, which have other features than their terrestrial analogues.

  19. Neuschwanstein and Pribram: Two solitaire meteorites or members of a stream?

    Science.gov (United States)

    Oberst, J.; Spurny, P.; Heinlein, D.

    2003-04-01

    The fall of the Neuschwanstein enstatite chondrite EL6 at 20:20:17.7 UTC on April 6, 2002, in Southern Bavaria is well documented. Using photographic records obtained by the European Fireball Network (EN), the heliocentric orbit of the object before its collision with Earth could be determined [Spurny et al., Nature, submitted]. Surprisingly, its orbit is practically identical to that of another meteorite, which was photographed by the EN 43 years earlier: the Pribram H5-chondrite, which fell on April 7, 1959. The orbital elements are extremely similar indeed, as is indicated by a D-criterion of D=0.025. By analysis of the orbital elements of all available (approx. 200) ''meteorite candidates'', we estimate that the chances of finding two meteorites with orbital elements matching as well as in the case of Pribram and Neuschwanstein is 1:100,000. Therefore, we believe that the paired fall is not a coincidence and that the meteorites are members of a stream of objects. Considering Innisfree and Ridgedale, another paired fall, observed by the Canadian MORP (Meteorite Observation and Recovery Project), in 1977 and 1980 [Halliday, Icarus 69, 550-556, 1987], it appears that meteorite streams are not uncommon among Earth-approaching objects. On the basis of the observational efficiency of the EN, we estimate that the Pribram/Neuschwanstein meteorite stream contains approx. 10^9 members; all of them combined would form an asteroid with a minimum radius of 300m. From studies of cometary-type meteor streams it is known that these cometary stream members have separated from their parent body fairly recently. However, judging from the different classifications of the meteorites, and from their long cosmic exposure (Pribram has a cosmic ray age of 19 Million years) both, a common parent and a recent separation, are not very likely.

  20. Delivery of asteroids and meteorites to the inner solar system

    International Nuclear Information System (INIS)

    Greenberg, R.; Nolan, M.C.

    1989-01-01

    This paper discusses how critical observational constraints on the delivery of asteroids (including the very small ones, called meteorites, that land on the Earth) include orbital distributions, exposure ages and mineralogy. Orbital maturity in the inner solar system is indicated by the AM/PM distribution of meteorite falls and fireballs: orbits with perihelia at 1 AU are less mature and arrive preferentially in the PM. Ordinary chondrites have short exposure ages, but their AM/PM fall statistics indicate significant orbital maturity. Hence, many may be collisional offspring of slightly larger parents that emigrated from the main belt. The required size distribution, extrapolated up to multi-km-size bodies, would also yield numbers of planet-crossing asteroids comparable to those astronomically observed. However, such a distribution requires launch on Earth-bound trajectories by catastrophic disruption events, which probably cannot launch sufficient material at high enough velocities Cratering events offer higher ejecta velocities, and if dominant would explain the abundance of basaltic meteorites relative to olivine, which should constitute the bulk of a differentiated parent body's volume

  1. Lunar Meteorites: A Global Geochemical Dataset

    Science.gov (United States)

    Zeigler, R. A.; Joy, K. H.; Arai, T.; Gross, J.; Korotev, R. L.; McCubbin, F. M.

    2017-01-01

    To date, the world's meteorite collections contain over 260 lunar meteorite stones representing at least 120 different lunar meteorites. Additionally, there are 20-30 as yet unnamed stones currently in the process of being classified. Collectively these lunar meteorites likely represent 40-50 distinct sampling locations from random locations on the Moon. Although the exact provenance of each individual lunar meteorite is unknown, collectively the lunar meteorites represent the best global average of the lunar crust. The Apollo sites are all within or near the Procellarum KREEP Terrane (PKT), thus lithologies from the PKT are overrepresented in the Apollo sample suite. Nearly all of the lithologies present in the Apollo sample suite are found within the lunar meteorites (high-Ti basalts are a notable exception), and the lunar meteorites contain several lithologies not present in the Apollo sample suite (e.g., magnesian anorthosite). This chapter will not be a sample-by-sample summary of each individual lunar meteorite. Rather, the chapter will summarize the different types of lunar meteorites and their relative abundances, comparing and contrasting the lunar meteorite sample suite with the Apollo sample suite. This chapter will act as one of the introductory chapters to the volume, introducing lunar samples in general and setting the stage for more detailed discussions in later more specialized chapters. The chapter will begin with a description of how lunar meteorites are ejected from the Moon, how deep samples are being excavated from, what the likely pairing relationships are among the lunar meteorite samples, and how the lunar meteorites can help to constrain the impactor flux in the inner solar system. There will be a discussion of the biases inherent to the lunar meteorite sample suite in terms of underrepresented lithologies or regions of the Moon, and an examination of the contamination and limitations of lunar meteorites due to terrestrial weathering. The

  2. Parents.

    Science.gov (United States)

    Hurst, Hunter, Ed.; And Others

    1986-01-01

    This document contains the fifth volume of "Today's Delinquent," an annual publication of the National Center for Juvenile Justice. This volume deals with the issue of the family and delinquency, examining the impact of parental behavior on the production of delinquent behavior. "Parents: Neglectful and Neglected" (Laurence D. Steinberg) posits…

  3. Irradiation history of meteoritic inclusions

    DEFF Research Database (Denmark)

    Wielandt, Daniel Kim Peel

    Understanding the formation and earliest evolution of our solar system is a longstanding goal shared by cosmochemistry, astronomy and astrophysics. Meteorites play a key role in this pursuit, providing a ground truth against which all theories must be weighed. Chondritic meteorites are in essence...... extraterrestrial sediments that contain Calcium-Aluminium-rich Inclusions (CAIs) and chondrules that formed as individual objects during the earliest stages of solar system evolution. They later accreted together to form large bodies, after spending up to several million years in individual orbit around the proto...... of presolar and protosolar materials, as well as evidence for the former presence of over 10 extinct shortlived radionuclei of varying stability and provenance that play a key role in deciphering early solar system evolution. Some shortlived radionuclei, such as 60Fe (T½ 2.5 Myr), must have formed...

  4. Terrestrial microbes in martian and chondritic meteorites

    Science.gov (United States)

    Airieau, S.; Picenco, Y.; Andersen, G.

    2007-08-01

    Introduction: The best extraterrestrial analogs for microbiology are meteorites. The chemistry and mineralogy of Asteroid Belt and martian (SNC) meteorites are used as tracers of processes that took place in the early solar system. Meteoritic falls, in particular those of carbonaceous chondrites, are regarded as pristine samples of planetesimal evolution as these rocks are primitive and mostly unprocessed since the formation of the solar system 4.56 billion years ago. Yet, questions about terrestrial contamination and its effects on the meteoritic isotopic, chemical and mineral characteristics often arise. Meteorites are hosts to biological activity as soon as they are in contact with the terrestrial biosphere, like all rocks. A wide biodiversity was found in 21 chondrites and 8 martian stones, and was investigated with cell culture, microscopy techniques, PCR, and LAL photoluminetry. Some preliminary results are presented here. The sample suite included carbonaceous chondrites of types CR, CV, CK, CO, CI, and CM, from ANSMET and Falls. Past studies documented the alteration of meteorites by weathering and biological activity [1]-[4]. Unpublished observations during aqueous extraction for oxygen isotopic analysis [5], noted the formation of biofilms in water in a matter of days. In order to address the potential modification of meteoritic isotopic and chemical signatures, the culture of microbial contaminating species was initiated in 2005, and after a prolonged incubation, some of the species obtained from cell culture were analyzed in 2006. The results are preliminary, and a systematic catalog of microbial contaminants is developing very slowly due to lack of funding. Methods: The primary method was cell culture and PCR. Chondrites. Chondritic meteorite fragments were obtained by breaking stones of approximately one gram in sterile mortars. The core of the rocks, presumably less contaminated than the surface, was used for the present microbial study, and the

  5. Survey on Cosmogenic 26Al in Lewis Cliff Meteorites

    Science.gov (United States)

    Welten, K. C.; Alderliesten, C.; Lindner, L.

    1992-07-01

    levels of 56 +- 7 and 60 +- 7 for H and L chondrites, respectively [3], range up to 800 ka with an average of about 290 ka. Altogether this may indicate that the Lewis Cliff blue-ice region is a relatively old meteorite stranding area. This is supported by preliminary conclusions based on ^36Cl, measured in 8 Lewis Cliff meteorites [4]. However, it is likely that some of our terrestrial ages have been overestimated due to (i) lower ^26Al saturation values for meteorites with preatmospheric radii less than 20 cm [3] and (ii) low exposure ages, resulting in initial ^26Al levels below 90-95% of the saturation level. These effects make individual terrestrial age determinations solely based on ^26Al content speculative as long as additional cosmogenic nuclide data are lacking. Dramatic changes in the overall picture are not expected, because (i) we have measured relatively large samples with an average recovered weight of about 500 g (one 11-kg sample excluded) and (ii) anomalously low exposure ages occur in about only 5% of the cases [5,6]. Possible correlations between terrestrial age and place of find will be discussed. UNUSUAL EXPOSURE HISTORIES: We excluded samples with extremely low NTL (financial support from the "Nederlandse Organisatie voor Wetenschappelijk Onderzoek" (NWO). References: 1. Komura K. et al. (1982) Mem. NIPR Spec. Issue 25, 178-187; 2. Evans J.C. and Reeves J.H. (1987) EPSL 82, 223-230; 3. Vogt S. (1990) LPI Tech. Rpt. 90-05, 112-118; 4. Nishizumi K. et al. (1991) Meteoritics 26 (abs.), 380; 5. Graf Th. and Marti K. (1990) Lunar Planet. Sci. XXI, 431-432; 6. Schultz L., Weber H.W. and Begemann F. (1991) GCA 55, 59-66; 7. Benoit P.H. et al. (1990) Ant. J. of the U.S. 25 (Rev.), 47-49.

  6. A dual origin for water in carbonaceous asteroids revealed by CM chondrites

    Science.gov (United States)

    Piani, Laurette; Yurimoto, Hisayoshi; Remusat, Laurent

    2018-04-01

    Carbonaceous asteroids represent the principal source of water in the inner Solar System and might correspond to the main contributors for the delivery of water to Earth. Hydrogen isotopes in water-bearing primitive meteorites, for example carbonaceous chondrites, constitute a unique tool for deciphering the sources of water reservoirs at the time of asteroid formation. However, fine-scale isotopic measurements are required to unravel the effects of parent-body processes on the pre-accretion isotopic distributions. Here, we report in situ micrometre-scale analyses of hydrogen isotopes in six CM-type carbonaceous chondrites, revealing a dominant deuterium-poor water component (δD = -350 ± 40‰) mixed with deuterium-rich organic matter. We suggest that this deuterium-poor water corresponds to a ubiquitous water reservoir in the inner protoplanetary disk. A deuterium-rich water signature has been preserved in the least altered part of the Paris chondrite (δDParis ≥ -69 ± 163‰) in hydrated phases possibly present in the CM rock before alteration. The presence of the deuterium-enriched water signature in Paris might indicate that transfers of ice from the outer to the inner Solar System were significant within the first million years of the history of the Solar System.

  7. Rare stable isotopes in meteorites

    International Nuclear Information System (INIS)

    Wilson, G.C.

    1981-01-01

    Secondary Ion Mass Spectrometry (SIMS) using accelerators has been applied with success to cosmic ray exposure ages and terrestrial residence times of meteorites by measuring cosmogenic nuclides of Be, Cl, and I. It is proposed to complement this work with experiments on rare stable isotopes, in the hope of setting constraints on the processes of solar nebula/meteoritic formation. The relevant species can be classified as: a) daughter products of extinct nuclides (halflife less than or equal to 2 x 10 8 y) -chronology of the early solar system; b) products of high temperature astrophysical processes - different components incorporated into the solar nebula; and c) products of relatively low temperature processes, stellar winds and cosmic ray reactions - early solar system radiation history. The use of micron-scale primary ion beams will allow detailed sampling of phases within meteorites. Strategies of charge-state selection, molecular disintegration and detection should bring a new set of targets within analytical range. The developing accelerator field is compared to existing (keV energy) ion microprobes

  8. Microfossils, biomolecules and biominerals in carbonaceous meteorites: implications to the origin of life

    Science.gov (United States)

    Hoover, Richard B.

    2012-11-01

    Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) investigations have shown that a wide variety of carbonaceous meteorites contain the remains of large filaments embedded within freshly fractured interior surfaces of the meteorite rock matrix. The filaments occur singly or in dense assemblages and mats and are often encased within carbon-rich, electron transparent sheaths. Electron Dispersive X-ray Spectroscopy (EDS) spot analysis and 2D X-Ray maps indicate the filaments rarely have detectable nitrogen levels and exhibit elemental compositions consistent with that interpretation that of the meteorite rock matrix. Many of the meteorite filaments are exceptionally well-preserved and show evidence of cells, cell-wall constrictions and specialized cells and processes for reproduction, nitrogen fixation, attachment and motility. Morphological and morphometric analyses permit many of the filaments to be associated with morphotypes of known genera and species of known filamentous trichomic prokaryotes (cyanobacteria and sulfur bacteria). The presence in carbonaceous meteorites of diagenetic breakdown products of chlorophyll (pristane and phytane) along with indigenous and extraterrestrial chiral protein amino acids, nucleobases and other life-critical biomolecules provides strong support to the hypothesis that these filaments represent the remains of cyanobacteria and other microorganisms that grew on the meteorite parent body. The absence of other life-critical biomolecules in the meteorites and the lack of detectable levels of nitrogen indicate the filaments died long ago and can not possibly represent modern microbial contaminants that entered the stones after they arrived on Earth. This paper presents new evidence for microfossils, biomolecules and biominerals in carbonaceous meteorites and considers the implications to some of the major hypotheses for the Origin of Life.

  9. Model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1984-01-01

    A model is presented for the differential fluxes of galactic-cosmic-ray (GCR) particles with energies above 1 MeV inside any spherical stony meteorite as a function of the meteorite's radius and the sample's depth. This model is based on the Reedy-Arnold equations for the energy-dependent fluxes of GCR particles in the moon and is an extension of flux parameters that were derived for several meteorites of various sizes. This flux is used to calculate the production rates of many cosmogenic nuclides as a function of radius and depth. The peak production rates for most nuclides made by the reactions of energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g cm -2 . Although the model has some limitations, it reproduces well the basic trends for the depth-dependent production of cosmogenic nuclides in stony meteorites of various radii. These production profiles agree fairly well with measurements of cosmogenic nuclides in meteorites. Some of these production profiles are different than those calculated by others. The chemical dependence of the production rates for several nuclides varies with size and depth. 25 references, 8 figures

  10. Variability in Abundances of Meteorites in the Ordovician

    Science.gov (United States)

    Heck, P. R.; Schmitz, B.; Kita, N.

    2017-12-01

    The knowledge of the flux of extraterrestrial material throughout Earth's history is of great interest to reconstruct the collisional evolution of the asteroid belt. Here, we present a review of our investigations of the nature of the meteorite flux to Earth in the Ordovician, one of the best-studied time periods for extraterrestrial matter in the geological record [1]. We base our studies on compositions of extraterrestrial chromite and chrome-spinel extracted by acid dissolution from condensed marine limestone from Sweden and Russia [1-3]. By analyzing major and minor elements with EDS and WDS, and three oxygen isotopes with SIMS we classify the recovered meteoritic materials. Today, the L and H chondrites dominate the meteorite and coarse micrometeorite flux. Together with the rarer LL chondrites they have a type abundance of 80%. In the Ordovician it was very different: starting from 466 Ma ago 99% of the flux was comprised of L chondrites [2]. This was a result of the collisional breakup of the parent asteroid. This event occurred close to an orbital resonance in the asteroid belt and showered Earth with >100x more L chondritic material than today during more than 1 Ma. Although the flux is much lower at present, L chondrites are still the dominant type of meteorites that fall today. Before the asteroid breakup event 467 Ma ago the three groups of ordinary chondrites had about similar abundances. Surprisingly, they were possibly surpassed in abundance by achondrites, materials from partially and fully differentiated asteroids [3]. These achondrites include HED meteorites, which are presumably fragments released during the formation of the Rheasilvia impact structure 1 Ga ago on asteroid 4 Vesta. The enhanced abundance of LL chondrites is possibly a result of the Flora asteroid family forming event at 1 Ga ago. The higher abundance of primitive achondrites was likely due to smaller asteroid family forming events that have not been identified yet but that did

  11. Gerontology of the Allende meteorite

    International Nuclear Information System (INIS)

    Jessberger, A.K.; Dominik, B.

    1979-01-01

    In the Allende meteorite several elements are found to have an isotopic composition that cannot be due to radioactive or spallation or fractionation processes. These isotope anomalies are mostly confined to white inclusions enriched in refractory elements (Ca-Al-rich inclusions) and are thought to be introduced into the Solar System by precondensed grains. The results of the Ar 40 -Ar 39 analysis of some coarse grained Allende inclusions that showed ages in excess of 4,550 Myr are here reported. (author)

  12. NASA Lunar and Meteorite Sample Disk Program

    Science.gov (United States)

    Foxworth, Suzanne

    2017-01-01

    The Lunar and Meteorite Sample Disk Program is designed for K-12 classroom educators who work in K-12 schools, museums, libraries, or planetariums. Educators have to be certified to borrow the Lunar and Meteorite Sample Disks by attending a NASA Certification Workshop provided by a NASA Authorized Sample Disk Certifier.

  13. Solar flare irradiation records in Antarctic meteorites

    International Nuclear Information System (INIS)

    Goswami, J.N.

    1981-01-01

    Observations of solar flare heavy nuclei tracks in eight Antartic meteorite samples are reported. Two of these were interior specimens from an L-3 chondrite which contained track-rich grains (olivine) indicating their exposure to solar flare irradiation before compaction of the meteorite. Preliminary noble gas data also indicate the presence of solar-type gases. (U.K.)

  14. Chemical Mixing Model and K-Th-Ti Systematics and HED Meteorites for the Dawn Mission

    Science.gov (United States)

    Usui, T.; McSween, H. Y., Jr.; Mittlefehldt, D. W.; Prettyman, T. H.

    2009-01-01

    The Dawn mission will explore 4 Vesta, a large differentiated asteroid believed to be the parent body of the howardite, eucrite and diogenite (HED) meteorite suite. The Dawn spacecraft carries a gamma-ray and neutron detector (GRaND), which will measure the abundances of selected elements on the surface of Vesta. This study provides ways to leverage the large geochemical database on HED meteorites as a tool for interpreting chemical analyses by GRaND of mapped units on the surface of Vesta.

  15. Studies on New Halfa Meteorite

    International Nuclear Information System (INIS)

    Abdu, Y.A.M.

    1996-01-01

    Mossbauer spectroscopy in the temperature range (295 deg K - 4.2 deg K), electron microprobe, and X-ray diffraction (XRD) measurements have been carried out for the investigation of a Sudanese meteorite, named New Halfa, from a new fall. The specimen contains well defined chondrules which consist mainly of radiating orthopyroxene and olivine. The XRD and the microprobe analysis show the presence of the silicate phases (olivine and pyroxene), iron sulphide (troilite), and Fe-Ni alloys (kamacite and taenite). The olivine appears to have a constant composition throughout the specimen, whereas pyroxene have a varying composition and both orthopyroxene (which is the dominant pyroxene) and clinopyroxene were present. The microprobe trace of Ni concentration across a kamacite-taenite-kamacite area shows a high Ni concentration at the interface between kamacite and taenite phases. The room temperature Mossbauer spectrum is fitted with with three sextets and two doublets. The sextets were assigned Fe in troilite, kamacite and taenite, and the two doublets to Fe 2+ in olivine and pyroxene (no Fe 3+ was found). The Mossbauer spectrum at 4.2 K shows that olivine, which is paramagnetic at room temperature, is magnetic showing relaxation effects. The Mossbauer data of this meteorite confirm it as an ordinary L-chondrite. (author). 19 refs., 5 tabs., 17 figs

  16. The meteoritic record of presolar and early solar system organic chemistry. [Abstract only

    Science.gov (United States)

    Cronin, John R.; Pizzarello, Sandra

    1994-01-01

    Carbon, hydrogen, and nitrogen isotopic analyses of various classes of organic compounds done in collaboration with Epstein and Krishnamurthy (Caltech) have shown these compounds to be enriched to varying degrees in the heavier isotopes. These results, in particular the large deuterium enrichments, have been interpreted as indicating an interstellar origin for the meteorite compounds or their precursors. Such isotopic fractionations, of hydrogen especially, are characteristic of low temperature ion-molecule reactions in cold interstellar clouds. There is also evidence from the large corresponding suites of alpha-amino and alpha-hydroxy acids found in meteorites suggesting that aqueous phase chemistry on the meteorite parent body played an important role in the formation of these compounds. These data support the hypothesis that interstellar compounds survived in the solar nebula at a radial distance corresponding to the asteroid belt, were incorporated into the parent body in icy, volatile-rich, planetesinals, and underwent further reactions during a period of aqueous activity within the early parent body to give the present suite of meteorite compounds. This formation hypothesis will be discussed and the results of recent isotopic and molecular analyses bearing on it will be presented.

  17. Laboratory simulation of meteoritic noble gases

    International Nuclear Information System (INIS)

    Zadnik, M.G.; Wacker, J.F.; Lewis, R.S.

    1985-01-01

    Sixteen amorphous carbon (lampblack) samples that had been exposed to Xe 127 and pumped for > 9 hrs to remove the most labile gas were examined by etching with HNO 3 , for comparison with the release pattern of meteoritic xenon. Samples originally exposed at 100 to 200 deg C lost 90% of their Xe very readily, when the surface had been etched to a mean depth of only approx. 0.2 A. This suggests that the Xe is adsorbed mainly at rare sites that are unusually reactive to HNO 3 . The adsorbed Xe survived several months' storage in vacuum, but on exposure to air, part of it was lost within a few hours, while the remainder persisted without measurable exchange. Samples exposed at 800 to 1000 deg C had a similar adsorbed component, as well as a second, tightly bound component extending to a mean depth of up to 30 A; this component had apparently diffused into the carbon during exposure. The (microscopic) diffusion coefficient for graphitic crystallites is 5 x 10 -20 cm 2 /sec at 1000 deg C. PVDC carbon lost its adsorbed Xe at about the same rate as lampblack on exposure to air or HNO 3 , though it differs from lampblack in being non-graphitizable and more porous. It had only a small diffused component, however. The results are discussed. (author)

  18. Early planetary metamorphism in chondritic meteorites

    International Nuclear Information System (INIS)

    Hanan, B.B.; Tilton, G.R.

    1985-01-01

    Lead isotope relations were studied in whole rock and separated phases of Mezoe-Madaras (L3) and Sharps (H3) chondrites in order to study the record of early events in the solar system and to seek further information on the isotopic composition of primordial lead. The internal 207 Pb/ 206 Pb ages are 4.480+-0.011 AE (1 AE=10 9 years) for Mezoe-Madaras and 4.472+-0.005 AE for Sharps. The ages are not significantly changed when Canyon Diablo troilite lead is included in the data sets, suggesting that the initial Pb isotopic composition in both meteorites was the same as that in the troilite. U-Pb data from both meteorites plot along chords in concordia diagrams that indicate recent disturbances in U/Pb ratios. The chords are poorly defined owing to the relatively non-radiogenic character of the lead isotopes. Rb-Sr measurements on Sharps likewise fail to yield an isochron, in agreement with the U-Pb data. Data from the literature indicate a similar disturbance in the Rb-Sr system for Mezoe-Madaras. The 4.48 AE ages could be caused by pre-analysis contamination with terrestrial lead, however statistical comparison of isotope correlations between the acid-washes of analyzed samples and the residual washed samples suggests that the ages are real and not due to terrestrial contamination. The 4.48 AE age, which is distinctly younger than the well-established ages of 4.54-4.56 AE for the Allende chondrite and Angra dos Reis achondrite, appears to date an early metamorphic event rather than the formation of the chondrites. Rb-Sr, Sm-Nd and K-Ar ages in support of the 4.48 AE metamorphic event are reviewed. Such a metamorphic age is not necessarily in conflict with 129 I/ 129 Xe data which indicate that the parent material of most chondrites, including those of type 3, cooled through temperatures sufficient to retain radiogenic Xe within a time interval of ca. 0.02 AE. (orig.)

  19. What we have learned about Mars from SNC meteorites

    Science.gov (United States)

    Mcsween, Harry Y., Jr.

    1994-01-01

    The SNC meteorites are thought to be igneous martian rocks, based on their young crystallization ages and a close match between the composition of gases implanted in them during shock and the atmosphere of Mars. A related meteorite, ALH84001, may be older and thus may represent ancient martian crust. These petrologically diverse basalts and ultramafic rocks are mostly cumulates, but their parent magmas share geochemical and radiogenic isotopic characteristics that suggest they may have formed by remelting the same mantle source region at different times. Information and inferences about martian geology drawn from these samples include the following: Planetary differentiation occured early at approximately 4.5 GA, probably concurrently with accretion. The martian mantle contains different abundances of moderately volatile and siderophile elements and is more Fe-rich than that of the Earth, which has implications for its mineralogy, density, and origin. The estimated core composition has a S abundance near the threshold value for inner core solidification. The former presence of a core dynamo may be suggested by remanent magnetization in Shergottite-Nakhlite-Chassignite (SNC) meteorites, although these rocks may have been magnetized during shock. The mineralogy of martian surface units, inferred from reflectance spectra, matches that of basaltic shergottites, but SNC lithologies thought to have crystallized in the subsurface are not presently recognized. The rheological properties of martian magmas are more accurately derived form these metorites than from observations of martian flow morphology, although the sampled range of magma compositions islimited. Estimates of planetary water abundance and the amount of outgassed water based on these meteorites are contridictory but overlap estimates based on geological observations and atmospheric measurements. Stable isotope measurements indicate that the martian hydrosphere experienced only limited exchange with the

  20. Cation ordering in orthopyroxenes and cooling rates of meteorites: Low temperature cooling rates of Estherville, Bondoc and Shaw

    Science.gov (United States)

    Ganguly, J.; Yang, H.; Ghose, S.

    1993-01-01

    The cooling rates of meteorites provide important constraints on the size of their parent bodies, and their accretionary and evolutionary histories. However, the cooling rates obtained so far from the commonly used metallographic, radiometric and fission-track methods have been sometimes quite controversial, such as in the case of the mesosiderites and the meteorite Shaw. We have undertaken a systematic study of the cooling rates of meteorites using a different approach, which involves single crystal x-ray determination of Fe(2+)-Mg ordering in orthopyroxenes (OP(x)) in meteorites, subject to bulk compositional constraints, and numerical simulation of the evolution of the ordering state as a function of cooling rate, within the framework of the thermodynamic and kinetic principles governing cation ordering. We report the results obtained for OP(x) crystals from Shaw and two mesosiderites, Estherville and Bondoc.

  1. Combining meteorites and missions to explore Mars.

    Science.gov (United States)

    McCoy, Timothy J; Corrigan, Catherine M; Herd, Christopher D K

    2011-11-29

    Laboratory studies of meteorites and robotic exploration of Mars reveal scant atmosphere, no evidence of plate tectonics, past evidence for abundant water, and a protracted igneous evolution. Despite indirect hints, direct evidence of a martian origin came with the discovery of trapped atmospheric gases in one meteorite. Since then, the study of martian meteorites and findings from missions have been linked. Although the meteorite source locations are unknown, impact ejection modeling and spectral mapping of Mars suggest derivation from small craters in terrains of Amazonian to Hesperian age. Whereas most martian meteorites are young ( 4.5 Ga and formation of enriched and depleted reservoirs. However, the history inferred from martian meteorites conflicts with results from recent Mars missions, calling into doubt whether the igneous histor y inferred from the meteorites is applicable to Mars as a whole. Allan Hills 84001 dates to 4.09 Ga and contains fluid-deposited carbonates. Accompanying debate about the mechanism and temperature of origin of the carbonates came several features suggestive of past microbial life in the carbonates. Although highly disputed, the suggestion spurred interest in habitable extreme environments on Earth and throughout the Solar System. A flotilla of subsequent spacecraft has redefined Mars from a volcanic planet to a hydrologically active planet that may have harbored life. Understanding the history and habitability of Mars depends on understanding the coupling of the atmosphere, surface, and subsurface. Sample return that brings back direct evidence from these diverse reservoirs is essential.

  2. Meteorites, Bolides and Comets: A Tale of Inconsistency

    Science.gov (United States)

    Jakes, P.; Padevet, V.

    1992-07-01

    copy appears here, shows fireball observations. Using the value of terminal velocities and the average value of ablation coefficients the terminal (residual) masses (m(sub)E) can be calculated. Among the bodies studied, 99 were heavier than 0.1 kg and 153 heavier than 0.01 kg. The parameter (m(sub)E) indicates the end of ablation in the atmosphere, but it cannot distinguish between meteoroids that were totally disintegrated and those genuinely decelerated. Similarly the calculated terminal altitudes and mechanical strength values do not provide a unequivocal interpretation. Correlation of bolide properties with meteorite falls could well be accommodated by the hypothesis B in which each bolide type has a meteorite equivalent. This has, however, some "outrageous" implications: comets may carry chondrites, icy dust balls do not produce fireballs; the extremely primitive carbon-rich particles represented by the IDPs do not form larger discrete bodies (fireballs) of "asteroidal" size; and the asteroid belt is a mixture of "native fractionated old bodies" together with the captured comets. Hypothesis B therefore contradicts the "established" scheme of the asteroid belt in which the non-differentiated meteorites (CI, CM, and CV) form the outer part of the asteroid belt, whereas the fractionated metamorphosed and igneous meteorites characterize the inner asteroids. References: [1] Whipple F. L., 1987, Phil. Trans. R. Soc. Lond., A 323, 339. [2] Dikov Yu. P. et al., 1991, Geochemistry International, 29, 33-38. [3] Kissel J., et al., 1986, Nature, 321, 326. [4] Solc M., et al., 1987, Publ. Astr. Inst. Czechosl., 67, 47. [5] Gombosi T. I. and Houpis H. L. F., 1986, Nature, 324, 43. [6] Delsemme A. H., 1977, Comets, asteroids, meteorites, Univ. of Toledo Press. [7] Gibson E. K., 1992, J. Geophys. Res., 97, E3 3865. [8] Ceplecha Z., 1988, Bull. Astr. Inst. Czech., 39, 221. [9] Spurny P., 1991, doc. diss., Astr. Inst. Czechosl. [10] Opik E. J., 1963, Adv. Astr. Astrophys., 2, 219

  3. Thermoluminescence studies of the thermal and radiation histories of chondritic meteorites

    International Nuclear Information System (INIS)

    Melcher, C.L.

    1980-01-01

    The thermoluminescence properties of chondritic meteorites are investigated to understand the ways in which the stored TL reflects the thermal and radiation histories of these objects. Differences in TL levels measured in recent falls are attributed to small differences in orbital temperatures. In addition, a correlation between TL level and terrestrial age is observed in meteorites of known terrestrial age. The thermoluminescence in chondrites is produced primarily by ionization from galactic cosmic rays with a much smaller contribution from the decay of natural radionuclides (U, Th, K, Rb). The production of most of the TL occurs after the break up of the large parent bodies into meter-size objects which are thus exposed to the ionizing effects of the cosmic rays. Measurements indicate that the low temperature TL represents a dynamic equilibrium between build up from ionizing radiation and thermal draining. The high temperature TL is near saturation. The terrestrial ages currently of greatest interest are those of the recently discovered meteorites in Antarctica. TL measurements were made on 11 of these meteorites and compared with the activities of 14 C, 26 Al, and 36 Cl measured by other workers in terrestrial age studies. A good correlation was found between the TL levels and the activities of cosmogenic radionuclides in these meteorites. Since the TL measurements can be made more rapidly and require much smaller samples (approx. 10 mg) than the radionuclide measurements, TL is most useful as a screening process to select potentially interesting samples for further study by more precise techniques

  4. Indigenous Amino Acids in Iron Meteorites

    Science.gov (United States)

    Elsila, J. E.; Dworkin, J. P.; Glavin, D. P.; Johnson, N. M.

    2018-01-01

    Understanding the organic content of meteorites and the potential delivery of molecules relevant to the origin of life on Earth is an important area of study in astrobiology. There have been many studies of meteoritic organics, with much focus on amino acids as monomers of proteins and enzymes essential to terrestrial life. The majority of these studies have involved analysis of carbonaceous chondrites, primitive meteorites containing approx. 3-5 wt% carbon. Amino acids have been observed in varying abundances and distributions in representatives of all eight carbonaceous chondrite groups, as well as in ungrouped carbonaceous chondrites, ordinary and R chondrites, ureilites, and planetary achondrites [1 and references therein].

  5. Atmospheric trajectory and heliocentric orbit of the Ejby meteorite fall in Denmark on February 6, 2016

    DEFF Research Database (Denmark)

    Spurný, P.; Borovička, Jan; Baumgarten, G.

    2017-01-01

    A very bright bolide illuminated the sky over Denmark and neighboring countries on February 6th, 2016 at 21:07:18-23UT. It terminated by a multiple meteorite fall in the heavily populated area of the western outskirts of Copenhagen. Several meteorites classified as the H5/6 ordinary chondrites have...... been found shortly after the fall and total recovered mass reached almost 9kg (Haack, 2016). Although this spectacular bolide has been reported by many casual witnesses, the instrumental records are very scarce, mainly due to bad weather over Denmark and neighboring countries. Despite it we were able...... this spectacular meteorite fall. We found that this event was caused by a relatively fragile 50cm meteoroid with initial mass about 250kg. It entered the atmosphere with velocity of 14.5kms-1 and quite steep entry angle of 62°. Its luminous flight started at 85.5km and after 76km long trajectory it terminated...

  6. Anomalous Enantiomer Ratios in Meteoritic Sugar Derivatives

    Science.gov (United States)

    Cooper, G.; Sant, M.; Asiyo, C.

    2009-03-01

    The enantiomer (mirror-image) ratios of sugar acids in carbonaceous meteorites have been measured. D-enantiomer excesses are found in all acids measured thus far. This includes rare as well as common compounds.

  7. Life on Mars: Evidence from Martian Meteorites

    Science.gov (United States)

    McKay, David S.; Thomas-Keptra, Katie L.; Clemett, Simon J.; Gibson, Everett K., Jr.; Spencer, Lauren; Wentworth, Susan J.

    2009-01-01

    New data on martian meteorite 84001 as well as new experimental studies show that thermal or shock decomposition of carbonate, the leading alternative non-biologic explanation for the unusual nanophase magnetite found in this meteorite, cannot explain the chemistry of the actual martian magnetites. This leaves the biogenic explanation as the only remaining viable hypothesis for the origin of these unique magnetites. Additional data from two other martian meteorites show a suite of biomorphs which are nearly identical between meteorites recovered from two widely different terrestrial environments (Egyptian Nile bottomlands and Antarctic ice sheets). This similarity argues against terrestrial processes as the cause of these biomorphs and supports an origin on Mars for these features.

  8. Meteorite Unit Models for Structural Properties

    Science.gov (United States)

    Agrawal, Parul; Carlozzi, Alexander A.; Karajeh, Zaid S.; Bryson, Kathryn L.

    2017-10-01

    To assess the threat posed by an asteroid entering Earth’s atmosphere, one must predict if, when, and how it fragments during entry. A comprehensive understanding of the asteroid material properties is needed to achieve this objective. At present, the meteorite material found on earth are the only objects from an entering asteroid that can be used as representative material and be tested inside a laboratory. Due to complex composition, it is challenging and expensive to obtain reliable material properties by means of laboratory test for a family of meteorites. In order to circumvent this challenge, meteorite unit models are developed to determine the effective material properties including Young’s modulus, compressive and tensile strengths and Poisson’s ratio, that in turn would help deduce the properties of asteroids. The meteorite unit model is a representative volume that accounts for diverse minerals, porosity, cracks and matrix composition.The Young’s Modulus and Poisson’s Ratio in the meteorite units are calculated by performing several hundreds of Monte Carlo simulations by randomly distributing the various phases inside these units. Once these values are obtained, cracks are introduced in these units. The size, orientation and distribution of cracks are derived by CT-scans and visual scans of various meteorites. Subsequently, simulations are performed to attain stress-strain relations, strength and effective modulus values in the presence of these cracks. The meteorite unit models are presented for H, L and LL ordinary chondrites, as well as for terrestrial basalt. In the case of the latter, data from the simulations is compared with experimental data to validate the methodology. These meteorite unit models will be subsequently used in fragmentation modeling of full scale asteroids.

  9. Thermoluminescence of meteorites and their orbits

    Science.gov (United States)

    Melcher, C. L.

    1981-01-01

    The thermoluminescence levels of 45 ordinary chondrites are measured in order to provide information on the orbital characteristics of the meteorites before impact. Glow curves of the photon emission response of powdered samples of the meteorites to temperatures up to 550 C in the natural state and following irradiation by a laboratory test dose of 110,000 rad were obtained as functions of terrestrial age and compared to those of samples of the Pribram, Lost City and Innisfree meteorites, for which accurate orbital data is available. The thermoluminescence levels in 40 out of 42 meteorites are found to be similar to those of the three control samples, indicating that the vast majority of ordinary chondrites that survive atmospheric entry have perihelia in the range 0.8-1 AU. Of the remaining two, Farmville is observed to exhibit an unusually large gradient in thermoluminescence levels with sample depth, which may be a result of a temperature gradient arising in a slowly rotating meteorite. Finally, the thermoluminescence measured in the Malakal meteorite is found to be two orders of magnitude lower than control samples, which is best explained by thermal draining by solar heating in an orbit with a perihelion distance of 0.5 to 0.6 AU.

  10. Mineralized remains of morphotypes of filamentous cyanobacteria in carbonaceous meteorites

    Science.gov (United States)

    Hoover, Richard B.

    2005-09-01

    rocks, living, cryopreserved and fossilized extremophiles and cyanobacteria. These studies have resulted in the detection of mineralized remains of morphotypes of filamentous cyanobacteria, mats and consortia in many carbonaceous meteorites. These well-preserved and embedded microfossils are consistent with the size, morphology and ultra-microstructure of filamentous trichomic prokaryotes and degraded remains of microfibrils of cyanobacterial sheaths. EDAX elemental studies reveal that the forms in the meteorites often have highly carbonized sheaths in close association with permineralized filaments, trichomes, and microbial cells. The eextensive protocols and methodologies that have been developed to protect the samples from contamination and to distinguish recent contaminants from indigenous microfossils are described recent bio-contaminants. Ratios of critical bioelements (C:O, C:N, C:P, and C:S) reveal dramatic differences between microfossils in Earth rocks and meteorites and in the cells, filaments, trichomes, and hormogonia of recently living cyanobacteria. The results of comparative optical, ESEM and FESEM studies and EDAX elemental analyses of recent cyanobacteria (e.g. Calothrix, Oscillatoria, and Lyngbya) of similar size, morphology and microstructure to microfossils found embedded in the Murchison CM2 and the Orgueil CI1 carbonaceous meteorites are presented

  11. Contemporary Inuit Traditional Beliefs Concerning Meteorites

    Science.gov (United States)

    Mardon, A. A.; Mardon, E. G.; Williams, J. S.

    1992-07-01

    Inuit religious mythology and the importance of meteorites as "messages" from the Creator of all things is only now being recognized. Field investigations near Resolute, Cornwallis Island in the high Canadian Arctic in 1988 are the bases for this paper. Through interpreters, several elders of the local Inuit described in detail the Inuit belief, recognition, and wonder at the falling meteors & meteorites during the long Polar Night and Polar Day. Such events are passed on in the oral tradition from generation to generation by the elders and especially those elders who fulfill the shamanistic roles. The Inuit have come across rocks that they immediately recognize as not being "natural" and in the cases of a fall that was observed and the rock recovered the meteorite is kept either on the person or in some hidden niche known only to that person. In one story recounted a meteorite fell and was recovered at the birth of one very old elder and the belief was that if the rock was somehow damaged or taken from his possession he would die. Some indirect indication also was conveyed that the discovery and possession of meteorites allow shaman to have "supernatural" power. This belief in the supernatural power of meteorites can be seen historically in many societies, including Islam and the "black rock" (Kaaba) of Mecca. It should also be noted, however, that metallic meteorites were clearly once the major source of iron for Eskimo society as is indicated from the recovery of meteoritical iron arrow heads and harpoon heads from excavated pre-Viking contact sites. The one evident thing that became clear to the author is that the Inuit distinctly believe that these meteorites are religious objects of the highest order and it brings into question the current academic practice of sending meteorites south to research institutes. Any seeming conflict with the traditional use of meteoric iron is more apparent than real--the animals, the hunt, and the act of survival--all being

  12. Heterogeneous Distributions of Amino Acids Provide Evidence of Multiple Sources Within the Almahata Sitta Parent Body, Asteroid 2008 TC(sub 3)

    Science.gov (United States)

    Burton, Aaron S.; Glavin, Daniel P.; Callahan, Michael P.; Dworkin, Jason P.; Jenniskens, Peter; Shaddad, Muawia H.

    2011-01-01

    Two new fragments of the Almahata Sitta meteorite and a sample of sand from the related strewn field in the Nubian Desert, Sudan, were analyzed for two to six carbon aliphatic primary amino acids by ultrahigh performance liquid chromatography with UV-fluorescence detection and time-of-flight mass spectrometry (LC-FT/ToF-MS). The distribution of amino acids in fragment #25, an H5 ordinary chondrite, and fragment #27, a polymict ureilite, were compared with results from the previously analyzed fragment #4, also a polymict ureilite. All three meteorite fragments contain 180-270 parts-per-billion (ppb) of amino acids, roughly 1000-fold lower than the total amino acid abundance of the Murchison carbonaceous chondrite. All of the Almahata Sitta fragments analyzed have amino acid distributions that differ from the Nubian Desert sand, which primarily contains L-alpha-amino acids. In addition, the meteorites contain several amino acids that were not detected in the sand, indicating that many of the amino acids are extraterrestrial in origin. Despite their petrological differences, meteorite fragments #25 and #27 contain similar amino acid compositions; however, the distribution of amino acids in fragment #27 was distinct from those in fragment #4, even though both arc polymict ureilites from the same parent body. Unlike in CM2 and CR2/3 meteorites, there are low relative abundances of alpha-amino acids in the Almahata Sitta meteorite fragments, which suggest that Strecker-type chemistry was not a significant amino acid formation mechanism. Given the high temperatures that asteroid 2008 TC3 appears to have experienced and lack of evidence for aqueous alteration on the asteroid, it is possible that the extraterrestrial amino acids detected in Almahata Sitta were formed by Fischer-Tropsch/Haber-Bosch type gas-grain reactions at elevated temperatures.

  13. Meteoritic Constraints on Models of the Solar Nebula: The Abundances of Moderately Volatile Elements

    Science.gov (United States)

    Cassen, Patrick; Cuzzi, Jeff (Technical Monitor)

    1994-01-01

    The "moderately volatile" elements are those which condense (or evaporate) in the temperature range 650 - 1350 K, as a mix of material with solar abundances is cooled (or heated) tinder equilibrium conditions. Their relative abundances in chondritic meteorites are solar (or "cosmic", as defined by the composition of Cl meteorites) to within a factor of several, but vary within that range in a way that correlates remarkably well with condensation temperature, independent of chemical affinity. It has been argued that this correlation reflects a systematically selective process which favored the accretion of refractory material over volatile material from a cooling nebula. Wasson and Chou (Meteoritics 9, 69-94, 1974, and Wasson and co-authors in subsequent papers) suggested that condensation and settling of solids contemporaneously with the cooling and removal of nebular gas could produce the observed abundance patterns, but a quantitative model has been lacking. We show that the abundance patterns of the moderately volatile elements in chondritic meteorites can be produced, in some degree of quantitative detail, by models of the solar nebula that are designed to conform to observations of T Tauri stars and the global conservation laws. For example, even if the local surface density of the nebula is not decreasing, condensation and accretion of solids from radially inflowing gas in a cooling nebula can result in depletions of volatiles, relative to refractories, like those observed, The details of the calculated abundance patterns depend on (but are not especially sensitive to) model parameters, and can exhibit the variations that distinguish the meteorite classes. Thus it appears that nebula characteristics such as cooling rates, radial flow velocities, and particle accumulation rates can be quantitatively constrained by demanding that they conform to meteoritic data; and the models, in turn, can produce testable hypotheses regarding the time and location of the

  14. CM : becoming a technology firm

    NARCIS (Netherlands)

    Burg, van J.C.; Reymen, I.M.M.J.; Dolmans, S.A.M.

    2011-01-01

    Founded in 2000 as a Short Message Service (SMS) marketing company for discos (clubs), CM evolved into a technology provider for SMS services. By 2008, CM was market leader in The Netherlands, a position won by offering high quality services at low prices. In 2010, the founders of the company were

  15. Water in Pyroxene and Olivine from Martian Meteorites

    Science.gov (United States)

    Peslier, A. H.

    2012-01-01

    Water in the interior of terrestrial planets can be dissolved in fluids or melts and hydrous phases, but can also be locked as protons attached to structural oxygen in lattice defects in nominally anhydrous minerals (NAM) like olivine, pyroxene, or feldspar [1-3]. Although these minerals contain only tens to hundreds of ppm H2O, this water can amount to at least one ocean in mass when added at planetary scales because of the modal dominance of NAM in the mantle and crust [4]. Moreover these trace amounts of water can have drastic effects on melting temperature, rheology, electrical and heat conductivity, and seismic wave attenuation [5]. There is presently a debate on how much water is present in the martian mantle. Secondary ionization mass spectrometry (SIMS) studies of NAM [6], amphiboles and glass in melt inclusions [7-10], and apatites [11, 12] from Martian meteorites report finding as much water as in the same phases from Earth's igneous rocks. Most martian hydrous minerals, however, generally have the relevant sites filled with Cl and F instead of H [13, 14], and experiments using Cl [15] in parent melts can reproduce Martian basalt compositions as well as those with water [16]. We are in the process of analyzing Martian meteorite minerals by Fourier transform infrared spectrometry (FTIR) in order to constrain the role of water in this planet s formation and magmatic evolution

  16. Determination of primordial and cosmogenic radioactivity in achondritic meteorites by low-level, gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Muntean, R.A.

    1979-08-01

    A high-sensitivity, low-background gamma-ray spectrometer containing two 23 cm by 13 cm thallium-activated, sodium iodide detectors was used to measure long-lived primordial and cosmogenic radioactivity in a suite of achondritic meteorites. Potassium, thorium, uranium, and 26 Al abundances were established for sixteen brecciated eucrites, two unbrecciated eucrites, a nakhlite, a chassignite, and a unique meteorite from Antarctica by nondestructive counting techniques. In several cases, multiple samples of the same meteorite fall were examined. Concentrations ranged from 79.8 ppM to 1150 ppM for potassium, 55.6 ppb to 663 ppb for thorium, 18.1 ppb to 190 ppb for uranium, and 45.0 dpm/kg to 99.0 dpm/kg for 26 Al. In addition, a 137 Cs concentration of 264 dpm/kg was observed in the Allan Hills 77005,9 specimen

  17. Isotopic coherence of refractory inclusions from CV and CK meteorites: Evidence from multiple isotope systems

    Science.gov (United States)

    Shollenberger, Quinn R.; Borg, Lars E.; Render, Jan; Ebert, Samuel; Bischoff, Addi; Russell, Sara S.; Brennecka, Gregory A.

    2018-05-01

    Calcium-aluminum-rich inclusions (CAIs) are the oldest dated materials in the Solar System and numerous previous studies have revealed nucleosynthetic anomalies relative to terrestrial rock standards in many isotopic systems. However, most of the isotopic data from CAIs has been limited to the Allende meteorite and a handful of other CV3 chondrites. To better constrain the isotopic composition of the CAI-forming region, we report the first Sr, Mo, Ba, Nd, and Sm isotopic compositions of two CAIs hosted in the CK3 desert meteorites NWA 4964 and NWA 6254 along with two CAIs from the CV3 desert meteorites NWA 6619 and NWA 6991. After consideration of neutron capture processes and the effects of hot-desert weathering, the Sr, Mo, Ba, Nd, and Sm stable isotopic compositions of the samples show clearly resolvable nucleosynthetic anomalies that are in agreement with previous results from Allende and other CV meteorites. The extent of neutron capture, as manifested by shifts in the observed 149Sm-150Sm isotopic composition of the CAIs is used to estimate the neutron fluence experienced by some of these samples and ranges from 8.40 × 1013 to 2.11 × 1015 n/cm2. Overall, regardless of CAI type or host meteorite, CAIs from CV and CK chondrites have similar nucleosynthetic anomalies within analytical uncertainty. We suggest the region that CV and CK CAIs formed was largely uniform with respect to Sr, Mo, Ba, Nd, and Sm isotopes when CAIs condensed and that CAIs hosted in CV and CK meteorites are derived from the same isotopic reservoir.

  18. Tellurium stable isotope fractionation in chondritic meteorites and some terrestrial samples

    Science.gov (United States)

    Fehr, Manuela A.; Hammond, Samantha J.; Parkinson, Ian J.

    2018-02-01

    New methodologies employing a 125Te-128Te double-spike were developed and applied to obtain high precision mass-dependent tellurium stable isotope data for chondritic meteorites and some terrestrial samples by multiple-collector inductively coupled plasma mass spectrometry. Analyses of standard solutions produce Te stable isotope data with a long-term reproducibility (2SD) of 0.064‰ for δ130/125Te. Carbonaceous and enstatite chondrites display a range in δ130/125Te of 0.9‰ (0.2‰ amu-1) in their Te stable isotope signature, whereas ordinary chondrites present larger Te stable isotope fractionation, in particular for unequilibrated ordinary chondrites, with an overall variation of 6.3‰ for δ130/125Te (1.3‰ amu-1). Tellurium stable isotope variations in ordinary chondrites display no correlation with Te contents or metamorphic grade. The large Te stable isotope fractionation in ordinary chondrites is likely caused by evaporation and condensation processes during metamorphism in the meteorite parent bodies, as has been suggested for other moderately and highly volatile elements displaying similar isotope fractionation. Alternatively, they might represent a nebular signature or could have been produced during chondrule formation. Enstatite chondrites display slightly more negative δ130/125Te compared to carbonaceous chondrites and equilibrated ordinary chondrites. Small differences in the Te stable isotope composition are also present within carbonaceous chondrites and increase in the order CV-CO-CM-CI. These Te isotope variations within carbonaceous chondrites may be due to mixing of components that have distinct Te isotope signatures reflecting Te stable isotope fractionation in the early solar system or on the parent bodies and potentially small so-far unresolvable nucleosynthetic isotope anomalies of up to 0.27‰. The Te stable isotope data of carbonaceous and enstatite chondrites displays a general correlation with the oxidation state and hence might

  19. Meteorites and the Evolution of Our Solar System

    Science.gov (United States)

    Nava, David F.

    1999-01-01

    The study of meteorites has long been of intense interest ever since these objects were discovered to be of extraterrestrial origin. Meteorite research contributes to unraveling the mysteries in understanding the formation and evolution processes of our solar system. Meteorites, of which there are a variety of widely diverse types of chemical and mineralogical compositions, are the most ancient of solar system objects that can be studied in the laboratory. They preserve a unique historical record of the astronomical and astrophysical events of our solar system. This record is being discerned by a host of ever evolving analytical laboratory methods. Recent discoveries of what are believed to be Martian meteorites, lunar meteorites, a meteorite containing indigenous water, and the recovery from the Cretaceous layer of a small meteorite fragment thought to be from the dinosaur-killing asteroid have fueled additional excitement for studying meteorites.

  20. Tungsten isotopic compositions of iron meteorites: Chronological constraints vs. cosmogenic effects

    Science.gov (United States)

    Markowski, A.; Quitté, G.; Halliday, A. N.; Kleine, T.

    2006-02-01

    High-precision W isotopic compositions are presented for 35 iron meteorites from 7 magmatic groups (IC, IIAB, IID, IIIAB, IIIF, IVA, and IVB) and 3 non-magmatic groups (IAB, IIICD, and IIE). Small but resolvable isotopic variations are present both within and between iron meteorite groups. Variations in the 182W/ 184W ratio reflect either time intervals of metal-silicate differentiation, or result from the burnout of W isotopes caused by a prolonged exposure to galactic cosmic rays. Calculated apparent time spans for some groups of magmatic iron meteorites correspond to 8.5 ± 2.1 My (IID), 5.1 ± 2.3 My (IIAB), and 5.3 ± 1.3 My (IVB). These time intervals are significantly longer than those predicated from models of planetesimal accretion. It is shown that cosmogenic effects can account for a large part of the W isotopic variation. No simple relationship exists with exposure ages, compromising any reliable method of correction. After allowance for maximum possible cosmogenic effects, it is found that there is no evidence that any of the magmatic iron meteorites studied here have initial W isotopic compositions that differ from those of Allende CAIs [ ɛ182W = - 3.47 ± 0.20; [T. Kleine, K. Mezger, H. Palme, E. Scherer and C. Münker, Early core formation in asteroids and late accretion of chondrite parent bodies: evidence from 182Hf- 182W in CAIs, metal-rich chondrites and iron meteorites, Geochim. Cosmochim. Acta (in press)]. Cosmogenic corrections cannot yet be made with sufficient accuracy to obtain highly precise ages for iron meteorites. Some of the corrected ages nevertheless require extremely early metal-silicate segregation no later than 1 My after formation of CAIs. Therefore, magmatic iron meteorites appear to provide the best examples yet identified of material derived from the first planetesimals that grew by runaway growth, as modelled in dynamic simulations. Non-magmatic iron meteorites have a more radiogenic W isotopic composition than magmatic

  1. DECODING THE MESSAGE FROM METEORITIC STARDUST SILICON CARBIDE GRAINS

    International Nuclear Information System (INIS)

    Lewis, Karen M.; Lugaro, Maria; Gibson, Brad K.; Pilkington, Kate

    2013-01-01

    Micron-sized stardust grains that originated in ancient stars are recovered from meteorites and analyzed using high-resolution mass spectrometry. The most widely studied type of stardust is silicon carbide (SiC). Thousands of these grains have been analyzed with high precision for their Si isotopic composition. Here we show that the distribution of the Si isotopic composition of the vast majority of stardust SiC grains carries the imprints of a spread in the age-metallicity distribution of their parent stars and of a power-law increase of the relative formation efficiency of SiC dust with the metallicity. This result offers a solution for the long-standing problem of silicon in stardust SiC grains, confirms the necessity of coupling chemistry and dynamics in simulations of the chemical evolution of our Galaxy, and constrains the modeling of dust condensation in stellar winds as a function of the metallicity.

  2. Noble Gases in the Lunar Meteorites Calcalong Creek and QUE 93069

    Science.gov (United States)

    Swindle, T. D.; Burkland, M. K.; Grier, J. A.

    1995-09-01

    Although the world's collections contain comparable numbers of martian and lunar meteorites (about 10 each), their ejection histories seem to be quite different [1]. We have sampled no more than four martian craters, but almost every one of the lunar meteorites apparently represents a separate cratering event. Furthermore, most lunar meteorites were apparently ejected from the top meter of the surface, unlike any of the martian meteorites. We have measured noble gases in two bulk samples of the lunar meteorite QUE93069 and three of Calcalong Creek, ranging in size from 7 to 15 mg. Averaged results are given in Table 1. Both meteorites contain solar-wind-implanted noble gas. QUE 93069, which is a mature anorthositic regolith breccia [2], contains amounts comparable to the most gas-rich lunar meteorites. The relatively low 40Ar/36Ar ratios of both meteorites suggest surface exposures no more than 2.5 Ga ago [3]. Calcalong Creek has readily observable spallogenic gas. The 131Xe/126Xe ratio of 4.8+/-0.3 corresponds to an average shielding depth of slightly more than 40 gm/cm^2 [4]. In common with many lunar breccias, Calcalong Creek has been exposed to cosmic rays for several hundred Ma (calculations based on [4] and [5]). The 3He apparent exposure age is much shorter, suggesting diffusive loss of He. To determine the detailed exposure history, it is necessary to have measurements of cosmogenic radionuclides. Our samples were too small to measure 81Kr, but [6] have measured 10Be, 26Al and 36Cl. Their data are consistent with either extended exposure at data, requiring several hundred Ma of exposure at an average depth of 40-50 gm/cm^2, are clearly more consistent with the first scenario. The only other lunar meteorite which could have been ejected at the same time is MAC 88104/5 [1], but the chemical differences between the two make it highly unlikely that they come from the same event. It is difficult to determine the amount of spallogenic gas in QUE 93069 because of

  3. Uranium-lead Isotope Evidence in the Shelyabinsk LL5 Chondrite Meteorite for Ancient and Recent Thermal Events

    Science.gov (United States)

    Lapen, T. J.; Kring, D. A.; Zolensky, M. E.; Andreasen, R.; Righter, M.; Swindle, T. D.; Beard, S. P.; Swindle, T. D.

    2014-01-01

    The impact histories on chondrite parent bodies can be deduced from thermochronologic analyses of materials and isotope systems with distinct apparent closure temperatures. It is especially critical to better understand the geological histories and physical properties of potenally hazardous near-Earth asteroids. Chelyabinsk is an LL5 chondrite meteorite that was dispersed over a wide area tens of kilometers south of the town of Chelyabinsk, Russia by an explosion at an altitude of 27 km at 3:22 UT on 15 Feb 2013 [1,2]. The explosion resulted in significant damage to surrounding areas and over 1500 injuries along with meteorite fragments being spread over a wide area [1].

  4. Catalogue of meteorites from South America

    CERN Document Server

    Acevedo, Rogelio Daniel; García, Víctor Manuel

    2014-01-01

    The first Catalogue of Meteorites from South America includes new specimens never previously reported, while doubtful cases and pseudometeorites have been deliberately omitted.The falling of these objects is a random event, but the sites where old meteorites are found tend to be focused in certain areas, e.g. in the deflation surfaces in Chile's Atacama Desert, due to favorable climate conditions and ablation processes.Our Catalogue provides basic information on each specimen like its provenance and the place where it was discovered (in geographic co-ordinates and with illustrative maps), its

  5. Comet and meteorite traditions of Aboriginal Australians

    Science.gov (United States)

    Hamacher, Duane W.

    2014-06-01

    This research contributes to the disciplines of cultural astronomy (the academic study of how past and present cultures understand and utilise celestial objects and phenomena) and geomythology (the study of geological events and the formation of geological features described in oral traditions). Of the hundreds of distinct Aboriginal cultures of Australia, many have oral traditions rich in descriptions and explanations of comets, meteors, meteorites, airbursts, impact events, and impact craters. These views generally attribute these phenomena to spirits, death, and bad omens. There are also many traditions that describe the formation of meteorite craters as well as impact events that are not known to Western science.

  6. Organic compounds in the Murchison meteorite.

    Science.gov (United States)

    Ponnamperuma, C.

    1972-01-01

    Impressive supporting evidence for the concept of the chemical evolution of life has appeared in the discovery of biologically important compounds in extraterrestrial samples. The approaches pursued to detect extraterrestrial organic compounds include the study of interstellar space by radioastronomy, the evaluation of the Apollo lunar samples, and the analysis of meteorites, both ancient and recent. It has been found that the clouds of gas in the interstellar medium contain a wide variety of molecules, most of which are organic in nature. The carbonaceous chondrites contain polymeric organic matter. Amino acids have been detected in the Murchison meteorite.

  7. Enantiomer Ratios of Meteoritic Sugar Derivatives

    Science.gov (United States)

    Cooper, George

    2012-01-01

    Carbonaceous meteorites contain a diverse suite of soluble organic compounds. Studies of these compounds reveal the Solar System's earliest organic chemistry. Among the classes of organic compounds found in meteorites are keto acids (pyruvic acid, etc.), hydroxy tricarboxylic acids (1), amino acids, amides, purines and pyrimidines. The Murchison and Murray meteorites are the most studied for soluble and insoluble organic compounds and organic carbon phases. The majority of (indigenous) meteoritic compounds are racemic, (i.e., their D/L enantiomer ratios are 50:50). However, some of the more unusual (non-protein) amino acids contain slightly more of one enantiomer (usually the L) than the other. This presentation focuses on the enantiomer analyses of three to six-carbon (3C to 6C) meteoritic sugar acids. The molecular and enantiomer analysis of corresponding sugar alcohols will also be discussed. Detailed analytical procedures for sugar-acid enantiomers have been described. Results of several meteorite analyses show that glyceric acid is consistently racemic (or nearly so) as expected of non-biological mechanisms of synthesis. Also racemic are 4-C deoxy sugar acids: 2-methyl glyceric acid; 2,4-dihydroxybutyric acid; 2,3-dihydroxybutyric acid (two diastereomers); and 3,4-dihydroxybutyric acid. However, a 4C acid, threonic acid, has never been observed as racemic, i.e., it possesses a large D excess. In several samples of Murchison and one of GRA 95229 (possibly the most pristine carbonaceous meteorite yet analyzed) threonic acid has nearly the same D enrichment. In Murchison, preliminary isotopic measurements of individual threonic acid enantiomers point towards extraterrestrial sources of the D enrichment. Enantiomer analyses of the 5C mono-sugar acids, ribonic, arabinonic, xylonic, and lyxonic also show large D excesses. It is worth noting that all four of these acids (all of the possible straight-chained 5C sugar acids) are present in meteorites, including the

  8. Evaluation of neutron cross sections for 244Cm, 246Cm, and 248Cm

    International Nuclear Information System (INIS)

    Benjamin, R.W.; McCrosson, F.J.; Gettys, W.E.

    1977-01-01

    An evaluation of neutron cross sections for 244 246 248 Cm using the ENDF/B format is presented. Primary data input included differential measurements, integral measurements, nuclear model calculations, and reactor production experience

  9. Origins of mass-dependent and mass-independent Ca isotope variations in meteoritic components and meteorites

    Science.gov (United States)

    Bermingham, K. R.; Gussone, N.; Mezger, K.; Krause, J.

    2018-04-01

    The Ca isotope composition of meteorites and their components may vary due to mass-dependent and/or -independent isotope effects. In order to evaluate the origin of these effects, five amoeboid olivine aggregates (AOAs), three calcium aluminum inclusions (CAIs), five chondrules (C), a dark inclusion from Allende (CV3), two dark fragments from North West Africa 753 (NWA 753; R3.9), and a whole rock sample of Orgueil (CI1) were analyzed. This is the first coupled mass-dependent and -independent Ca isotope dataset to include AOAs, a dark inclusion, and dark fragments. Where sample masses permit, Ca isotope data are reported with corresponding petrographic analyses and rare earth element (REE) relative abundance patterns. The CAIs and AOAs are enriched in light Ca isotopes (δ44/40Ca -5.32 to +0.72, where δ44/40Ca is reported relative to SRM 915a). Samples CAI 5 and AOA 1 have anomalous Group II REE patterns. These REE and δ44/40Ca data suggest that the CAI 5 and AOA 1 compositions were set via kinetic isotope fractionation during condensation and evaporation. The remaining samples show mass-dependent Ca isotope variations which cluster between δ44/40Ca +0.53 and +1.59, some of which are coupled with unfractionated REE abundance patterns. These meteoritic components likely formed through the coaccretion of the evaporative residue and condensate following Group II CAI formation or their chemical and isotopic signatures were decoupled (e.g., via nebular or parent-body alteration). The whole rock sample of Orgueil has a δ44/40Ca +0.67 ± 0.18 which is in agreement with most published data. Parent-body alteration, terrestrial alteration, and variable sampling of Ca-rich meteoritic components can have an effect on δ44/40Ca compositions in whole rock meteorites. Samples AOA 1, CAI 5, C 2, and C 4 display mass-independent 48/44Ca anomalies (ε48/44Ca +6 to +12) which are resolved from the standard composition. Other samples measured for these effects (AOA 5, CAI 1, CAI 2

  10. Oblique impact: a process for providing meteorite samples of other planets

    International Nuclear Information System (INIS)

    Okeefe, J.D.; Ahrens, T.J.

    1986-03-01

    Cratering flow calculations for a series of oblique to normal impacts of silicate projectiles onto a silicate halfspace were carried out to determine whether the gas produced upon shock vaporizing both projectile and planetary material could entrain and accelerate surface rocks and thus provide a mechanism for propelling SNC meteorites from the Martian surface. The difficult constraints that the impact origin hypothesis for SNC meteorites has to satisfy are that these meteorites are lightly to moderately shocked and yet were accelerated to speeds in excess of the Martian escape velocity. Two dimensional finite difference calculations demonstrate that at highly probable impact velocities, vapor plume jets are produced at oblique impact angles of 25 deg to 60 deg and have speeds as great as 20 km/sec. These plumes flow nearly parallel to the planetary surface. It is shown that upon impact of projectiles having radii of 0.1 to 1 km, the resulting vapor jets have densities of 0.1 to 1 g/cu.cm. These jets can entrain Martian surface rocks and accelerate them to velocities 5 km/sec. It is suggested that this mechanism launches SNC meteorites to Earth

  11. 600 MeV Simulation of the Production of Cosmogenic Nuclides in Meteorites by Galactic Protons

    CERN Multimedia

    2002-01-01

    A large variety of stable and radioactive nuclides is produced by the interaction of solar and galactic cosmic rays with extraterrestrial matter. Measurements of such cosmogenic nuclides provide information about the constancy of cosmic ray fluxes in space and time and about the irradiation history of individual extraterrestrial objects provided that there exist reliable models describing the production process. For the calculation of the depth dependent production of cosmogenic nuclides in meteorites no satisfactory Therefore, the irradiation of small stony meteorites (radii~$<$~40~cm) by galactic protons is simulated in a series of thick target irradiation experiments at the 600~MeV proton beam of the SC. \\\\ \\\\ The thick targets are spheres (R = 5, 15, 25 cm) and are made out of diorite because of its low water content, its high density (3.0~g/cm|3) and because it provides a good approximation of the chemical composition of some common meteorite clas These spheres will also contain a wide variety of pure...

  12. 344 cm x 86 cm low mass vacuum window

    International Nuclear Information System (INIS)

    Reimers, R.M.; Porter, J.; Meneghetti, J.; Wilde, S.; Miller, R.

    1983-08-01

    The LBL Heavy Ion Spectrometer System (HISS) superconducting magnet contains a 1 m x 3.45 m x 2 m vacuum tank in its gap. A full aperture thin window was needed to minimize background as the products of nuclear collisions move from upstream targets to downstream detectors. Six windows were built and tested in the development process. The final window's unsupported area is 3m 2 with a 25 cm inward deflection. The design consists of a .11 mm Nylon/aluminum/polypropylene laminate as a gas seal and .55 mm woven aramid fiber for strength. Total mass is 80 milligrams per cm 2 . Development depended heavily on past experience and testing. Safety considerations are discussed

  13. Compound-Specific Carbon, Nitrogen, and Hydrogen Isotopic Ratios for Amino Acids in CM and CR Chondrites and their use in Evaluating Potential Formation Pathways

    Science.gov (United States)

    Elsila, Jamie E.; Charnley, Steven B.; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-01-01

    Stable hydrogen, carbon, and nitrogen isotopic ratios (oD, 013C, and olSN) of organic compounds can revcal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may indicate the most likely of these pathways. We have applied gas chromatography with mass spectrometry and combustion isotope ratio mass spectrometry to measure the compound-specific C, N, and H stable isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites: CM1I2 Allan Hills (ALH) 83100, CM2 Murchison, CM2 Lewis Cliff (LEW) 90500, CM2 Lonewolf Nunataks (LON) 94101, CRZ Graves Nunataks (GRA) 95229, CRZ Elephant Moraine (EET) 92042, and CR3 Queen Alexandra Range (QUE) 99177. We compare the isotopic compositions of amino acids in these meteorites with predictions of expected isotopic enrichments from potential formation pathways. We observe trends of decreasing ODC and increasing oD with increasing carbon number in the aH, (l-NH2 amino acids that correspond to predictions made for formation via Streckercyanohydrin synthesis. We also observe light ODC signatures for -alanine, which may indicate either formation via Michael addition or via a pathway that forms primarily small, straight-chain, amine-terminal amino acids (n-ro-amino acids). Higher deuterium enrichments are observed in amethyl amino acids, indicating formation of these amino acids or their precursors in cold interstellar or nebular environments. Finally, individual amino acids are more enriched in deuterium in CR chondrites than CM chondrites, reflecting different parent-body chemistry.

  14. No evidence for a decrease of nuclear decay rates with increasing heliocentric distance based on radiochronology of meteorites

    Science.gov (United States)

    Meier, Matthias M. M.; Wieler, Rainer

    2014-03-01

    It has been argued that the decay rates of several radioactive nuclides are slightly lower at Earth's aphelion than at perihelion, and that this effect might depend on heliocentric distance. It might then be expected that nuclear decay rates be considerably lower at larger distances from the sun, e.g., in the asteroid belt at 2-3 AU from where most meteorites originate. If so, ages of meteorites obtained by analyses of radioactive nuclides and their stable daughter isotopes might be in error, since these ages are based on decay rates determined on Earth. Here we evaluate whether the large data base on nuclear cosmochronology offers any hint for discrepancies which might be due to radially variable decay rates. Chlorine-36 (t1/2 = 301,000 a) is produced in meteorites by interactions with cosmic rays and is the nuclide for which a decay rate dependence from heliocentric distance has been proposed, which, in principle, can be tested with our approach and the current data base. We show that compilations of 36Cl concentrations measured in meteorites offer no support for a spatially variable 36Cl decay rate. For very short-lived cosmic-ray produced radionuclides (half-lives uranium decay rates in different meteorite parent bodies in the asteroid belt. Moreover, the oldest U-Pb ages of meteorites agree with the main-sequence age of the sun derived from helioseismology within the formal ˜1% uncertainty of the latter. Meteorite ages also provide no evidence for a decrease of decay rates with heliocentric distance for nuclides such as 87Rb (decay mode β-) 40K (β- and electron capture), and 147Sm (α).

  15. Meteorite Dichotomy Implies that Jupiter Formed Early

    Science.gov (United States)

    Kruijer, T. S.; Burkhardt, C.; Budde, G.; Kleine, T.

    2018-05-01

    Meteorites derive from two distinct nebular reservoirs that co-existed and remained spatially separated between 1 and 3–4 Ma after CAIs. This can most easily be explained if Jupiter acted as a barrier and formed early, within less than 1 Ma.

  16. Organics in meteorites - Solar or interstellar?

    Science.gov (United States)

    Alexander, Conel M. O'D.; Cody, George D.; Fogel, Marilyn; Yabuta, Hikaru

    2008-10-01

    The insoluble organic material (IOM) in primitive meteorites is related to the organic material in interplanetary dust particles and comets, and is probably related to the refractory organic material in the diffuse interstellar medium. If the IOM is representative of refractory ISM organics, models for how and from what it formed will have to be revised.

  17. Mössbauer study of Slovak meteorites

    Science.gov (United States)

    Lipka, J.; Sitek, J.; Dekan, J.; Degmová, J.; Porubčan, V.

    2013-04-01

    57Fe Mössbauer spectroscopy was used as an analytical tool in the investigation of iron containing compounds of two meteorites (Rumanová and Košice) out of total of six which had fallen on Slovak territory. In the magnetic fraction of the iron bearing compounds in the Rumanová meteorite, maghemite, troilite and Fe-Ni alloy were identified. In the non-magnetic fraction silicate phases were found, such as olivine and pyroxene. The paramagnetic component containing Fe3 + ions corresponds probably to small superparamagnetic particles. The Košice meteorite was found near the town of Košice in February 2010. Its magnetic fraction consists of a Fe-Ni alloy with the Mössbauer parameters of the magnetic field corresponding to kamacite α-Fe(Ni, Co) and troilite. The non-magnetic part consists of Fe2 + phases such as olivine and pyroxene and traces of a Fe3 + phase. The main difference between these meteorites is their iron oxide content. These kinds of analyses can bring important knowledge about phases and compounds formed in extraterrestrial conditions, which have other features than their terrestrial analogues.

  18. Determination of Meteorite Porosity Using Liquid Nitrogen

    Science.gov (United States)

    Kohout, T.; Kletetschka, G.; Pesonen, L. J.; Wasilewski, P. J.

    2005-01-01

    We introduce a new harmless method for porosity measurement suitable for meteorite samples. The method is a modification of the traditional Archimedean method based on immersion of the samples in a liquid medium like water or organic liquids. In our case we used liquid nitrogen for its chemically inert characteristics.

  19. Magnetism in meteorites. [terminology, principles and techniques

    Science.gov (United States)

    Herndon, J. M.; Rowe, M. W.

    1974-01-01

    An overview of this subject is presented. The paper includes a glossary of magnetism terminology and a discussion of magnetic techniques used in meteorite research. These techniques comprise thermomagnetic analysis, alternating field demagnetization, thermal demagnetization, magnetic anisotropy, low-temperature cycling, and coercive forces, with emphasis on the first method. Limitations on the validity of paleointensity determinations are also discussed.

  20. THE NITROGEN ISOTOPIC COMPOSITION OF METEORITIC HCN

    Energy Technology Data Exchange (ETDEWEB)

    Pizzarello, Sandra, E-mail: pizzar@asu.edu [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85018-1604 (United States)

    2014-12-01

    HCN is ubiquitous in extraterrestrial environments and is central to current theories on the origin of early solar system organic compounds such as amino acids. These compounds, observed in carbonaceous meteorites, were likely important in the origin and/or evolution of early life. As part of our attempts to understand the origin(s) of meteoritic CN{sup –}, we have analyzed the {sup 15}N/{sup 14}N isotopic composition of HCN gas released from water extracts of the Murchison meteorite and found its value to be near those of the terrestrial atmosphere. The findings, when evaluated viz-a-viz molecular abundances and isotopic data of meteoritic organic compounds, suggest that HCN formation could have occurred during the protracted water alteration processes known to have affected the mineralogy of many asteroidal bodies during their solar residence. This was an active synthetic stage, which likely involved simple gasses, organic molecules, their presolar precursors, as well as mineral catalysts and would have lead to the formation of molecules of differing isotopic composition, including some with solar values.

  1. Modeling the Thermal Interactions of Meteorites Below the Antarctic Ice

    Science.gov (United States)

    Oldroyd, William Jared; Radebaugh, Jani; Stephens, Denise C.; Lorenz, Ralph; Harvey, Ralph; Karner, James

    2017-10-01

    Meteorites with high specific gravities, such as irons, appear to be underrepresented in Antarctic collections over the last 40 years. This underrepresentation is in comparison with observed meteorite falls, which are believed to represent the actual population of meteorites striking Earth. Meteorites on the Antarctic ice sheet absorb solar flux, possibly leading to downward tunneling into the ice, though observations of this in action are very limited. This descent is counteracted by ice sheet flow supporting the meteorites coupled with ablation near mountain margins, which helps to force meteorites towards the surface. Meteorites that both absorb adequate thermal energy and are sufficiently dense may instead reach a shallow equilibrium depth as downward melting overcomes upward forces during the Antarctic summer. Using a pyronometer, we have measured the incoming solar flux at multiple depths in two deep field sites in Antarctica, the Miller Range and Elephant Moraine. We compare these data with laboratory analogues and model the thermal and physical interactions between a variety of meteorites and their surroundings. Our Matlab code model will account for a wide range of parameters used to characterize meteorites in an Antarctic environment. We will present the results of our model along with depth estimates for several types of meteorites. The recovery of an additional population of heavy meteorites would increase our knowledge of the formation and composition of the solar system.

  2. Cosmic-ray exposure records and origins of meteorites

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1985-01-01

    The cosmic-ray records of meteorites can be used to infer much about their origins and recent histories. Some meteorites had simple cosmic-ray exposure histories, while others had complex exposure histories with their cosmogenic products made both before and after a collision in space. The methods used to interpret meteorites' cosmic-ray records, especially identifying simple or complex exposure histories, often are inadequate. Besides spallogenic radionuclides and stable nuclides, measurements of products that have location-sensitive production rates, such as the tracks of heavy cosmic-ray nuclei or neutron-capture nuclides, are very useful in accurately determining a meteorite's history. Samples from different, known locations of a meteorite help in studying the cosmic-ray record. Such extensive sets of meteorite measurements, plus theoretical modeling of complex histories, will improve our ability to predict the production of cosmogenic nuclides in meteorites, to distinguish simple and complex exposure histories, and to better determine exposure ages

  3. Curation of US Martian Meteorites Collected in Antarctica

    Science.gov (United States)

    Lindstrom, M.; Satterwhite, C.; Allton, J.; Stansbury, E.

    1998-01-01

    To date the ANSMET field team has collected five martian meteorites (see below) in Antarctica and returned them for curation at the Johnson Space Center (JSC) Meteorite Processing Laboratory (MPL). ne meteorites were collected with the clean procedures used by ANSMET in collecting all meteorites: They were handled with JSC-cleaned tools, packaged in clean bags, and shipped frozen to JSC. The five martian meteorites vary significantly in size (12-7942 g) and rock type (basalts, lherzolites, and orthopyroxenite). Detailed descriptions are provided in the Mars Meteorite compendium, which describes classification, curation and research results. A table gives the names, classifications and original and curatorial masses of the martian meteorites. The MPL and measures for contamination control are described.

  4. Elemental composition analysis of stony meteorites discovered in Phitsanulok, Thailand

    Science.gov (United States)

    Loylip, T.; Wannawichian, S.

    2017-09-01

    A meteorite is a fragment of pure stone, iron or the mixture of stony-iron. The falling of meteorites into Earth’s surface is part of Earth’s accretion process from dust and rocks in our solar system. When these fragments come close enough to the Earth to be attracted by its gravity, they may fall into the Earth. Following the detection of objects that fall from the sky onto a home in Phitsanulok in June 27, the meteorites were analyzed by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS) instruments. The results from SEM/EDS analysis show that the meteorites are mainly composed of Fe-Ni and Fe-s. The meteorite is Achondrite, a class of meteorite which does not contain Chondrule. The meteorites in this work are thought to be part of a large asteroid.

  5. Meteorite and meteoroid: New comprehensive definitions

    Science.gov (United States)

    Rubin, A.E.; Grossman, J.N.

    2010-01-01

    Meteorites have traditionally been defined as solid objects that have fallen to Earth from space. This definition, however, is no longer adequate. In recent decades, man-made objects have fallen to Earth from space, meteorites have been identified on the Moon and Mars, and small interplanetary objects have impacted orbiting spacecraft. Taking these facts and other potential complications into consideration, we offer new comprehensive definitions of the terms "meteorite,""meteoroid," and their smaller counterparts: A meteoroid is a 10-??m to 1-m-size natural solid object moving in interplanetary space. A micrometeoroid is a meteoroid 10 ??m to 2 mm in size. A meteorite is a natural, solid object larger than 10 ??m in size, derived from a celestial body, that was transported by natural means from the body on which it formed to a region outside the dominant gravitational influence of that body and that later collided with a natural or artificial body larger than itself (even if it is the same body from which it was launched). Weathering and other secondary processes do not affect an object's status as a meteorite as long as something recognizable remains of its original minerals or structure. An object loses its status as a meteorite if it is incorporated into a larger rock that becomes a meteorite itself. A micrometeorite is a meteorite between 10 ??m and 2 mm in size. Meteorite- "a solid substance or body falling from the high regions of the atmosphere" (Craig 1849); "[a] mass of stone and iron that ha[s] been directly observed to have fallen down to the Earth's surface" (translated from Cohen 1894); "[a] solid bod[y] which came to the earth from space" (Farrington 1915); "A mass of solid matter, too small to be considered an asteroid; either traveling through space as an unattached unit, or having landed on the earth and still retaining its identity" (Nininger 1933); "[a meteoroid] which has reached the surface of the Earth without being vaporized" (1958

  6. Isotopically Anomalous Carbonaceous Nanoglobules in Meteorites and Comets

    Science.gov (United States)

    de Gregorio, B. T.; Alexander, C.; Bassim, N. D.; Cody, G. D.; Kilcoyne, D.; Nittler, L.; Stroud, R.; Zega, T. J.

    2009-12-01

    Sub-micron, spherical, organic globules are prevalent in primitive meteorites and interplanetary dust particles. Many of these globules are significantly enriched in 15N and/or D, relative to solar values, which suggest that they or their precursors formed in cold regions of the solar nebula or in interstellar molecular clouds. We have used correlated transmission electron microscopy (TEM), synchrotron-based X-ray absorption near-edge structure spectroscopy (XANES), and secondary ion mass spectrometry (SIMS) to determine the elemental and isotopic composition and organic functional group chemistry of individual carbonaceous nanoglobules in a suite of insoluble organic matter (IOM) residues prepared from carbonaceous and ordinary chondrites, and two additional organic globules from the Stardust comet 81P/Wild 2 sample collection. The majority of the meteoritic nanoglobules have a similar chemistry to the bulk IOM, with, on average, a small but significant enrichment in aromatic ketone (-C=O) and carboxyl (-COOH) functional groups. However, some of the meteoritic nanoglobules and one of the Stardust nanoglobules contain highly aromatic organic matter with no significant oxygen functionality. Preliminary measurements indicate that the highest 15N enrichments are associated with the highly aromatic nanoglobules and that aromatic nanoglobules are more prevalent in IOM from more primitive meteorites (e.g. Bells contains more aromatic globules than Murchison). For example, of two adjacent nanoglobules with nearly identical hollow morphologies from Murchison, one contains highly aromatic organic matter and the other contains oxidized IOM-like organic matter. SIMS analysis of these two globules reveals that the highly aromatic globule has the greatest 15N enrichment (δ15N ~ +500‰) of all meteoritic globules in which both XANES and SIMS was performed, whereas the adjacent IOM-like globule has a smaller 15N enrichment (δ15N ~ +300‰) but still greater than bulk IOM (δ15

  7. Correlated silicon and titanium isotopic compositions of presolar SiC grains from the Murchison CM2 chondrite

    Science.gov (United States)

    Gyngard, Frank; Amari, Sachiko; Zinner, Ernst; Marhas, Kuljeet Kaur

    2018-01-01

    We report correlated Si, and Ti isotopic compositions and elemental concentrations of 238 presolar SiC grains from the Murchison CM2 meteorite. Combined with measurements of the C and N isotopic compositions of these 238 grains, 220 were determined to be of type mainstream, 10 type AB, 4 type Y and 4 type Z. SiC grains of diameter ≳2.5 μm, to ensure enough material to attempt Ti measurements, were randomly chosen without any other prejudice. The Ti isotopic compositions of the majority of the grains are characterized by enrichments in 46Ti, 47Ti, 49Ti, and 50Ti relative to 48Ti, and show linear isotopic correlations indicative of galactic chemical evolution and neutron capture of the grains parent stars. The variability in the observed Ti signal as a function of depth in most of the grains indicates the presence of distinct subgrains, likely TiC that have been previously observed in TEM studies. Vandium-51 concentrations correlate with those of Ti, indicating V substitutes for Ti in the TiC matrix in many of the grains. No isotopic anomalies in 52Cr/53Cr ratios were observed, and Cr concentrations did not correlate with those of either Ti or V.

  8. An ion microprobe study of CAIs from CO3 meteorites. [Abstract only

    Science.gov (United States)

    Russell, S. S.; Greenwood, R. C.; Fahey, A. J.; Huss, G. R.; Wasserburg, G. J.

    1994-01-01

    When attempting to interpret the history of Ca, Al-rich inclusions (CAIs) it is often difficult to distinguish between primary features inherited from the nebula and those produced during secondary processing on the parent body. We have undertaken a systematic study of CAIs from 10 CO chondrites, believed to represent a metamorphic sequence with the goal of distinguishing primary and secondary features. ALHA 77307 (3.0), Colony (3.0), Kainsaz (3.1), Felix (3.2), ALH 82101 (3.3), Ornans (3.3), Lance (3.4), ALHA 77003 (3.5), Warrenton (3.6), and Isna (3.7) were examined by Scanning Electron Microscopy (SEM) and optical microscopy. We have identified 141 CAIs within these samples, and studied in detail the petrology of 34 inclusions. The primary phases in the lower petrologic types are spinel, melilite, and hibonite. Perovskite, FeS, ilmenite, anorthite, kirschsteinite, and metallic Fe are present as minor phases. Melilite becomes less abundant in higher petrologic types and was not detected in chondrites of type 3.5 and above, confirming previous reports that this mineral easily breaks down during heating. Iron, an element that would not be expected to condense at high temperatures, has a lower abundance in spinel from low-petrologic-type meteorites than those of higher grade, and CaTiO3 is replaced by FeTiO3 in meteorites of higher petrologic type. The abundance of CAIs is similar in each meteorite. Eight inclusions have been analyzed by ion probe. The results are summarized. The results obtained to date show that CAIs in CO meteorites, like those from other meteorite classes, contain Mg* and that Mg in some inclusions has been redistributed.

  9. Fused Bead Analysis of Diogenite Meteorites

    Science.gov (United States)

    Mittlefehldt, D.W.; Beck, B.W.; McSween, H.Y.; Lee, C.T. A.

    2009-01-01

    Bulk rock chemistry is an essential dataset in meteoritics and planetary science [1]. A common method used to obtain the bulk chemistry of meteorites is ICP-MS. While the accuracy, precision and low detection limits of this process are advantageous [2], the sample size used for analysis (approx.70 mg) can be a problem in a field where small and finite samples are the norm. Fused bead analysis is another bulk rock analytical technique that has been used in meteoritics [3]. This technique involves forming a glass bead from 10 mg of sample and measuring its chemistry using a defocused beam on a microprobe. Though the ICP-MS has lower detection limits than the microprobe, the fused bead method destroys a much smaller sample of the meteorite. Fused bead analysis was initially designed for samples with near-eutectic compositions and low viscosities. Melts generated of this type homogenize at relatively low temperatures and produce primary melts near the sample s bulk composition [3]. The application of fused bead analysis to samples with noneutectic melt compositions has not been validated. The purpose of this study is to test if fused bead analysis can accurately determine the bulk rock chemistry of non-eutectic melt composition meteorites. To determine this, we conduct two examinations of the fused bead. First, we compare ICP-MS and fused bead results of the same samples using statistical analysis. Secondly, we inspect the beads for the presence of crystals and chemical heterogeneity. The presence of either of these would indicate incomplete melting and quenching of the bead.

  10. Genealogy of Iron and Pallasite Meteorites as Revealed by Cr Isotopes

    Science.gov (United States)

    Sanborn, M.; Yin, Q. Z.; Ziegler, K. G.

    2017-12-01

    The parent bodies and/or chemical reservoirs from which iron and stony-iron meteorites originated are not very well understood. It is unclear if particular groups of iron or stony-iron meteorites originated from melting of already known chondritic parent bodies or are representating new chemical reservoirs. Potential connections between iron meteorites and pallasites and known parent bodies have been suggested based on oxygen isotopes. Proposed genetic relationships include the IVA irons with ordinary chondrites1 and the anomalous pallasite Eagle Station with the CV chondrites2. Here, we use the power of Cr isotopes to further resolve potential connections between IVA irons and pallasites and specific parent bodies. Our new measurements of Cr isotopic composition of silicate inclusions from two IVA irons, Steinbach and São João Nepomuceno, are shown to be indistinguishable from that of the ordinary chondrites. Coupling Cr with oxygen indicates the IVA irons likely originated from the same source as LL chondrites. In contrast with Eagle Station, the new Cr isotope measurements combined with oxygen indicates the MGP Brenham and Krasnojarsk sampled a source material similar to that of the anomalous HEDs. As with Eagle Station, the Milton pallasite exhibits a carbonaceous chondrite (CC) Cr isotope composition, indicating that Eagle Station was not the lone case of a pallasite originating from a CC reservoir. By establishing these genetic relationships using Cr isotopes, it is now evident that the differentiation activity sampled by IVA irons and pallasites represents processes occurring on a diverse set of parent bodies in the early Solar System. [1] Ruzicka and Hutson (2006) MAPS, 41, 1959. [2] Shukolyukov and Lugmair (2006) EPSL, 250, 200.

  11. Isotopic and Chemical Evidence for Primitive Aqueous Alteration in the Tagish Lake Meteorite

    Science.gov (United States)

    Sakuma, Keisuke; Hidaka, Hiroshi; Yoneda, Shigekazu

    2018-01-01

    Aqueous alteration is one of the primitive activities that occurred on meteorite parent bodies in the early solar system. The Tagish Lake meteorite is known to show an intense parent body aqueous alteration signature. In this study, quantitative analyses of the alkaline elements and isotopic analyses of Sr and Ba from acid leachates of TL (C2-ungrouped) were performed to investigate effects of aqueous alteration. The main purpose of this study is to search for isotopic evidence of extinct 135Cs from the Ba isotopic analyses in the chemical separates from the Tagish Lake meteorite. Barium isotopic data from the leachates show variable 135Ba isotopic anomalies (ε = ‑2.6 ∼ +3.6) which correlatewith 137Ba and 138Ba suggesting a heterogeneous distribution of s- and r-rich nucleosynthetic components in the early solar system. The 87Rb–87Sr and 135Cs–135Ba decay systems on TL in this study do not provide any chronological information. The disturbance of the TL chronometers is likely a reflection of the selective dissolution of Cs and Rb given the relatively higher mobility of Cs and Rb compared to Ba and Sr, respectively, during fluid mineral interactions.

  12. Tracing meteorite source regions through asteroid spectroscopy

    Science.gov (United States)

    Thomas, Cristina Ana

    By virtue of their landing on Earth, meteorites reside in near-Earth object (NEO) orbits prior to their arrival. Thus the population of observable NEOs, in principle, gives the best representation of meteorite source bodies. By linking meteorites to NEOs, and linking NEOs to their most likely main-belt source locations, we seek to gain insight into the original solar system formation locations for different meteorite classes. To forge the first link between meteorites and NEOs, we have developed a three dimensional method for quantitative comparisons between laboratory measurements of meteorites and telescopic measurements of near-Earth objects. We utilize meteorite spectra from the Reflectance Experiment Laboratory (RELAB) database and NEO data from the SpeX instrument on the NASA Infrared Telescope Facility (IRTF). Using the Modified Gaussian Model (MGM) as a mathematical tool, we treat asteroid and meteorite spectra identically in the calculation of 1-micron and 2-micron geometric band centers and their band area ratios (BARs). Using these identical numerical parameters we quantitatively compare the spectral properties of S-, Sq-, Q- and V-type NEOs with the spectral properties of the meteorites in the H, L, LL and HED meteorite classes. For each NEO spectrum, we assign a set of probabilities for it being related to each of these meteorite classes. Our NEO- meteorite correlation probabilities are then convolved with NEO-source region probabilities to yield a final set of meteorite-source region correlations. An apparent (significant at the 2.1-sigma level) source region signature is found for the H chondrites to be preferentially delivered to the inner solar system through the 3:1 mean motion resonance. A 3:1 resonance H chondrite source region is consistent with the short cosmic ray exposure ages known for H chondrites. The spectroscopy of asteroids is subject to several sources of inherent error. The source region model used a variety of S-type spectra without

  13. 5cm aperture dipole studies

    International Nuclear Information System (INIS)

    McInturff, A.D.; Bossert, R.; Carson, J.; Fisk, H.E.; Hanft, R.; Kuchnir, M.; Lundy, R.; Mantech, P.; Strait, J.

    1986-01-01

    The results obtained during the evolution of the design, construction, and testing program of the design ''B'' dipole are presented here. Design ''B'' is one of the original three competing designs for the Superconducting Super Collider ''SSC'' arc dipoles. The final design parameters were as follows: air cored (less than a few percent of the magnetic field derived from any iron present), aluminum collared, two layered winding, 5.5T maximum operating field, and a 5 cm cold aperture. There have been fourteen 64 cm long 5 cm aperture model dipoles cold tested (at 4.3K and less) in this program so far. There was a half length full size (6m) mechanical analog (M-10) built and tested to check the cryostat's mechanical design under ramping and quench conditions. Several deviations from the ''Tevatron'' dipole fabrication technique were incorporated, for example the use of aluminum collars instead of stainless steel. The winding technique variations explored were ''dry welding,'' a technique with the cable covered with Kapton insulation only and ''wet winding'' where the Kapton was covered with a light coat of ''B'' stage epoxy. Test data include quench currents, field quality (Fourier multipole co-efficients), coil magnetization, conductor current performance, and coil loading. Quench current, loss per cycle, and harmonics were measured as a function of the magnitude and rate of change of the magnetic field, and helium bath temperature

  14. Isotopic and chemical variation of organic nanoglobules in primitive meteorites

    Science.gov (United States)

    de Gregorio, Bradley T.; Stroud, Rhonda M.; Nittler, Larry R.; Alexander, Conel M. O'd.; Bassim, Nabil D.; Cody, George D.; Kilcoyne, A. L. David; Sandford, Scott A.; Milam, Stefanie N.; Nuevo, Michel; Zega, Thomas J.

    2013-05-01

    Organic nanoglobules are microscopic spherical carbon-rich objects present in chondritic meteorites and other astromaterials. We performed a survey of the morphology, organic functional chemistry, and isotopic composition of 184 nanoglobules in insoluble organic matter (IOM) residues from seven primitive carbonaceous chondrites. Hollow and solid nanoglobules occur in each IOM residue, as well as globules with unusual shapes and structures. Most nanoglobules have an organic functional chemistry similar to, but slightly more carboxyl-rich than, the surrounding IOM, while a subset of nanoglobules have a distinct, highly aromatic functionality. The range of nanoglobule N isotopic compositions was similar to that of nonglobular 15N-rich hotspots in each IOM residue, but nanoglobules account for only about one third of the total 15N-rich hotspots in each sample. Furthermore, many nanoglobules in each residue contained no 15N enrichment above that of bulk IOM. No morphological indicators were found to robustly distinguish the highly aromatic nanoglobules from those that have a more IOM-like functional chemistry, or to distinguish 15N-rich nanoglobules from those that are isotopically normal. The relative abundance of aromatic nanoglobules was lower, and nanoglobule diameters were greater, in more altered meteorites, suggesting the creation/modification of IOM-like nanoglobules during parent-body processing. However, 15N-rich nanoglobules, including many with highly aromatic functional chemistry, likely reflect preaccretionary isotopic fractionation in cold molecular cloud or protostellar environments. These data indicate that no single formation mechanism can explain all of the observed characteristics of nanoglobules, and their properties are likely a result of multiple processes occurring in a variety of environments.

  15. Pyroxene microstructure in the Northwest Africa 856 martian meteorite

    Science.gov (United States)

    Leroux, Hugues; Devouard, Bertrand; Cordier, Patrick; Guyot, François

    2004-05-01

    Transmission electron microscopy was used to examine pyroxene microstructure in the Northwest Africa (NWA) 856 martian meteorite to construct its cooling and shock histories. All pyroxenes contain strained coherent pigeonite/augite exsolution lamellae on (001). The average width and periodicity of lamellae are 80 and 400 nm, respectively, indicating a cooling rate below 0.1 °C/hr for the parent rock. Pigeonite and augite are topotactic, with strained coherent interfaces parallel to (001). The closure temperature for Ca-Fe, Mg interdiffusion, estimated from the composition at the augite pigeonite interface, is about 700 °C. Tweed texture in augite reveals that a spinodal decomposition occurred. Locally, tweed evolved toward secondary pigeonite exsolutions on (001). Due to the decreasing diffusion rate with decreasing temperature, "M-shaped" concentration profiles developed in augite lamellae. Pigeonite contains antiphase boundaries resulting from the C2/c to P21/c space group transition that occurred during cooling. The reconstructive phase transition from P21/c clinopyroxene to orthopyroxene did not occur. The deformation (shock) history of the meteorites is revealed by the presence of dislocations and mechanical twins. Dislocations are found in glide configuration, with the [001](100) glide system preferentially activated. They exhibit strong interaction with the strained augite/pigeonite interfaces and did not propagate over large distances. Twins are found to be almost all parallel to (100) and show moderate interaction with the augite/pigeonite interfaces. These twins are responsible for the plastic deformation of the pyroxene grains. Comparison with microstructure of shocked clinopyroxene (experimentally or naturally shocked) suggests that NWA 856 pyroxenes are not strongly shocked.

  16. Dhajala meteorite shower: atmospheric fragmentation and ablation based on cosmic ray track studies

    Energy Technology Data Exchange (ETDEWEB)

    Bagolia, C; Doshi, N; Gupta, S K; Kumar, S; Lal, D; Trivedi, J R [Physical Research Lab., Ahmedabad (India)

    1977-06-01

    Cosmic-ray track studies have been carried out in more than 250 fragments of Dhajala meteorite comprising greater than 70% of the recovered mass. In the case of larger fragments (namely, those with mass exceeding 250 g) several faces of each fragment have been analysed for track densities. Track densities are low, and fall generally in the range (10/sup 3/ to 10/sup 5/)cm/sup -2/, indicating appreciable ablation losses since the cosmic ray exposure age of Dhajala is about 7 m.y. (track measurements were confined to large olivine grains to minimize contributions to tracks due to the fission of uranium and extinct radionuclides). Attempts have been made to deduce information about fragmentation dynamics and the preatmospheric mass/radius of Dhajala, based on the present comprehensive study of track densities in the fragments. Correlations between the position of a fragment in the strewnfield and its track density have provided an approximate scenario for the fragmentation/ablation of the meteorite during its atmospheric flight. Observation of minimum track density in the fragments lead to a value of (38 +- 2)cm for the preatmospheric radius of the meteorite. It is estimated from these data that the collection of fragments was made with an overall efficiency of approximately 60% and that the ablation amounts to (86.7 +- 2.1)%. Estimated amounts of ablation for shells of different radii are also presented.

  17. Flux of low-energy particles in the solar system: the record in St. Severin meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Lal, D [Physical Research Lab., Ahmedabad (India); Marti, K

    1977-06-01

    Some data are presented for the St. Severin meteorite which indicate appreciable contributions due to nuclear reactions of low-energy particles of energy < 200 MeV. Some or most of these may be of solar origin; a part of the low-energy flux may in fact be galactic in origin, if modulation effects are less severe at 2 to 4 A.U. distances compared to that near the Earth or the Moon. These conclusions are based on a study of the concentrations of spallogenic gases and cosmic-ray tracks in seven samples to depths down to about 2.5 cm along a core taken from a fragment of the meteorite.

  18. Cosmic-ray production rates of neon isotopes in meteorite minerals

    International Nuclear Information System (INIS)

    Bhandari, N.

    1988-01-01

    The rates of production of 21 Ne and 22 Ne in spallation reactions, both due to solar as well as galactic cosmic rays, in some major meteoritic minerals, e.g. olivines, feldspars and pyroxenes, are calculated using their energy spectra and excitation functions. The production profiles of 21 Ne and 22 Ne due to galactic cosmic rays, and the 22 Ne/ 21 Ne ratio depend upon the size of the meteoroid. The 22 Ne/ 21 Ne ratio is very sensitive to the abundance of sodium and consequently its depth profile is distinctly different in feldspars, the ratio increasing with depth rather than decreasing as in pyroxenes and olivines. In the near-surface regions, up to a depth of 2 cm, production due to solar flare protons dominates, giving rise to a steep gradient in isotopic production as well as in the 22 Ne/ 21 Ne ratio. Composite production profiles are given and compared with measurements in some meteorites. (author). 22 refs

  19. Molybdenum isotopic evidence for the origin of chondrules and a distinct genetic heritage of carbonaceous and non-carbonaceous meteorites

    Science.gov (United States)

    Budde, Gerrit; Burkhardt, Christoph; Brennecka, Gregory A.; Fischer-Gödde, Mario; Kruijer, Thomas S.; Kleine, Thorsten

    2016-11-01

    Nucleosynthetic isotope anomalies are powerful tracers to determine the provenance of meteorites and their components, and to identify genetic links between these materials. Here we show that chondrules and matrix separated from the Allende CV3 chondrite have complementary nucleosynthetic Mo isotope anomalies. These anomalies result from the enrichment of a presolar carrier enriched in s-process Mo into the matrix, and the corresponding depletion of this carrier in the chondrules. This carrier most likely is a metal and so the uneven distribution of presolar material probably results from metal-silicate fractionation during chondrule formation. The Mo isotope anomalies correlate with those reported for W isotopes on the same samples in an earlier study, suggesting that the isotope variations for both Mo and W are caused by the heterogeneous distribution of the same carrier. The isotopic complementary of chondrules and matrix indicates that both components are genetically linked and formed together from one common reservoir of solar nebula dust. As such, the isotopic data require that most chondrules formed in the solar nebula and are not a product of protoplanetary impacts. Allende chondrules and matrix together with bulk carbonaceous chondrites and some iron meteorites (groups IID, IIIF, and IVB) show uniform excesses in 92Mo, 95Mo, and 97Mo that result from the addition of supernova material to the solar nebula region in which these carbonaceous meteorites formed. Non-carbonaceous meteorites (enstatite and ordinary chondrites as well as most iron meteorites) do not contain this material, demonstrating that two distinct Mo isotope reservoirs co-existed in the early solar nebula that remained spatially separated for several million years. This separation was most likely achieved through the formation of the gas giants, which cleared the disk between the inner and outer solar system regions parental to the non-carbonaceous and carbonaceous meteorites. The Mo isotope

  20. Scaling analysis of meteorite shower mass distributions

    DEFF Research Database (Denmark)

    Oddershede, Lene; Meibom, A.; Bohr, Jakob

    1998-01-01

    Meteorite showers are the remains of extraterrestrial objects which are captivated by the gravitational field of the Earth. We have analyzed the mass distribution of fragments from 16 meteorite showers for scaling. The distributions exhibit distinct scaling behavior over several orders of magnetude......; the observed scaling exponents vary from shower to shower. Half of the analyzed showers show a single scaling region while the orther half show multiple scaling regimes. Such an analysis can provide knowledge about the fragmentation process and about the original meteoroid. We also suggest to compare...... the observed scaling exponents to exponents observed in laboratory experiments and discuss the possibility that one can derive insight into the original shapes of the meteoroids....

  1. 15 cm mercury multipole thruster

    Science.gov (United States)

    Longhurst, G. R.; Wilbur, P. J.

    1978-01-01

    A 15 cm multipole ion thruster was adapted for use with mercury propellant. During the optimization process three separable functions of magnetic fields within the discharge chamber were identified: (1) they define the region where the bulk of ionization takes place, (2) they influence the magnitudes and gradients in plasma properties in this region, and (3) they control impedance between the cathode and main discharge plasmas in hollow cathode thrusters. The mechanisms for these functions are discussed. Data from SERT II and cusped magnetic field thrusters are compared with those measured in the multipole thruster. The performance of this thruster is shown to be similar to that of the other two thrusters. Means of achieving further improvement in the performance of the multipole thruster are suggested.

  2. Nature of Reduced Carbon in Martian Meteorites

    Science.gov (United States)

    Gibson, Everett K., Jr.; McKay, D. S.; Thomas-Keprta, K. L.; Clemett, S. J.; White, L. M.

    2012-01-01

    Martian meteorites provide important information on the nature of reduced carbon components present on Mars throughout its history. The first in situ analyses for carbon on the surface of Mars by the Viking landers yielded disappointing results. With the recognition of Martian meteorites on Earth, investigations have shown carbon-bearing phases exist on Mars. Studies have yielded presence of reduced carbon, carbonates and inferred graphitic carbon phases. Samples ranging in age from the first approximately 4 Ga of Mars history [e.g. ALH84001] to nakhlites with a crystallization age of 1.3 Ga [e.g. Nakhla] with aqueous alteration processes occurring 0.5-0.7 Ga after crystallizaton. Shergottites demonstrate formation ages around 165-500 Ma with younger aqueous alterations events. Only a limited number of the Martian meteorites do not show evidence of significance terrestrial alterations. Selected areas within ALH84001, Nakhla, Yamato 000593 and possibly Tissint are suitable for study of their indigenous reduced carbon bearing phases. Nakhla possesses discrete, well-defined carbonaceous phases present within iddingsite alteration zones. Based upon both isotopic measurements and analysis of Nakhla's organic phases the presence of pre-terrestrial organics is now recognized. The reduced carbon-bearing phases appear to have been deposited during preterrestrial aqueous alteration events that produced clays. In addition, the microcrystalline layers of Nakhla's iddingsite have discrete units of salt crystals suggestive of evaporation processes. While we can only speculate on the origin of these unique carbonaceous structures, we note that the significance of such observations is that it may allow us to understand the role of Martian carbon as seen in the Martian meteorites with obvious implications for astrobiology and the pre-biotic evolution of Mars. In any case, our observations strongly suggest that reduced organic carbon exists as micrometer- size, discrete structures

  3. Analyses of Rumanová meteorite

    Science.gov (United States)

    Lipka, J.; Sitek, J.; Dekan, J.; Sedlačková, K.

    2014-04-01

    Mössbauer spectroscopy was used as an analytical tool in investigation of iron containing compounds of Rumanová meteorite found on Slovak territory and it was classified as chondrite H. The results showed that the Mössbauer spectra consist of magnetic and non-magnetic components related to different iron-bearing phases. In non-magnetic part, olivine, pyroxene, and traces of Fe3 + phases have been identified. The magnetically ordered part of the Rumanová meteorite spectrum consists of kamacite, troilite and the third additional component corresponds to hydroxides originating from weathering due to being long time on the Earth surface. The weathering products can be recognised mainly as maghemite, however traces of other weathering components as akagaenite, goethite and magnetite cannot be excluded. On the contrary to Rumanová, no weathering products have been found in the sample of Košice meteorite which fell on the territory of Slovakia in February 2010 and has been investigated a few months after the fall.

  4. De Magnete et Meteorite: Cosmically Motivated Materials

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, LH; Pinkerton, FE; Bordeaux, N; Mubarok, A; Poirier, E; Goldstein, JI; Skomski, R; Barmak, K

    2014-01-01

    Meteorites, likely the oldest source of magnetic material known to mankind, are attracting renewed interest in the science and engineering community. Worldwide focus is on tetrataenite, a uniaxial ferromagnetic compound with the tetragonal L1(0) crystal structure comprised of nominally equiatomic Fe-Ni that is found naturally in meteorites subjected to extraordinarily slow cooling rates, as low as 0.3 K per million years. Here, the favorable permanent magnetic properties of bulk tetrataenite derived from the meteorite NWA 6259 are quantified. The measured magnetization approaches that of Nd-Fe-B (1.42 T) and is coupled with substantial anisotropy (1.0-1.3 MJ/m(3)) that implies the prospect for realization of technologically useful coercivity. A highly robust temperature dependence of the technical magnetic properties at an elevated temperature (20-200 degrees C) is confirmed, with a measured temperature coefficient of coercivity of -0.005%/ K, over one hundred times smaller than that of Nd-Fe-B in the same temperature range. These results quantify the extrinsic magnetic behavior of chemically ordered tetrataenite and are technologically and industrially significant in the current context of global supply chain limitations of rare-earth metals required for present-day high-performance permanent magnets that enable operation of a myriad of advanced devices and machines.

  5. Studies on Al Kidirate and Kapoeta meteorites

    International Nuclear Information System (INIS)

    Gismelseed, A.M.; Khangi, F.; Ibrahim, A.; Yousif, A.A.; Worthing, M.A.; Rais, A.; Elzain, M.E.; Brooks, C.K.; Sutherland, H.H.

    1994-01-01

    Moessbauer spectroscopy (20-300 K), magnetic susceptibility measurements (77-350 K), scanning electron microscopy and X-ray diffraction experiments have been performed on two meteorite samples: one from an old fall (Kapoeta) and another from a very recent fall (Al Kidirate). The two specimens differ in their mineralogy. Chondrules appear to be absent in Kapoeta and it is probably a pyroxene-plagioclase achondrite with ferrohypersthene as the most abundant mineral. On the other hand, the Al Kidirate meteorite is an ordinary chondrite and the specimen consists of olivine, orthopyroxene, troilite and kamacite. The Moessbauer measurements confirm the above characterization, showing a paramagnetic doublet for the Kapoeta sample and at least two paramagnetic doublets and magnetic sextets for the Al Kidirate specimens. The former were assigned to Fe in pyroxene sites, while the latter was assigned to Fe in pyroxene, olivine, Fe-S and Fe-Ni alloys. The difference in the mineralogy of the two meteorites has also been reflected in the temperature-dependent magnetic susceptibility. The magnetization and the hyperfine interaction parameters will be discussed in relation to the mineralogy. (orig.)

  6. Field Guide to Meteors and Meteorites

    CERN Document Server

    Norton, O. Richard

    2008-01-01

    Imagine the unique experience of being the very first person to hold a newly-found meteorite in your hand – a rock from space, older than Earth! "Weekend meteorite hunting" with magnets and metal detectors is becoming ever more popular as a pastime, but of course you can’t just walk around and pick up meteorites in the same way that you can pick up seashells on the beach. Those fragments that survived the intense heat of re-entry tend to disguise themselves as natural rocks over time, and it takes a trained eye – along with the information in this book – to recognize them. Just as amateur astronomers are familiar with the telescopes and accessories needed to study a celestial object, amateur meteoriticists have to use equipment ranging from simple hand lenses to microscopes to study a specimen, to identify its type and origins. Equipment and techniques are covered in detail here of course, along with a complete and fully illustrated guide to what you might find and where you might find it. In fact, th...

  7. Cosmic-ray exposure records and origins of meteorites

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1985-01-01

    The cosmic-ray records of meteorites are used to infer much about their origins and recent histories. The methods used to interpret meteorites cosmic-ray records, especially identifying simple or complex exposure histories, often are inadequate. Spallogenic radionuclides, stable nuclides, and measurements of products that have location-sensitive production rates, such as the tracks of heavy cosmic-ray nuclei or neutron-capture nuclides, are very useful in accurately determining a meteorite's history. Samples from different, known locations of a meteorite help in studying the cosmic-ray record. Such extensive sets of meteorite measuremetns, plus theoretical modeling of complex histories, improves the ability to predict the production of cosmogenic nuclides in meteorites, to distinguish simple and complex exposure histories, and to better determine exposure ages

  8. Oxygen isotope systematics of chondrules in the Murchison CM2 chondrite and implications for the CO-CM relationship

    Science.gov (United States)

    Chaumard, Noël; Defouilloy, Céline; Kita, Noriko T.

    2018-05-01

    High-precision oxygen three-isotope measurements of olivine and pyroxene were performed on 29 chondrules in the Murchison CM2 chondrite by secondary ion mass spectrometry (SIMS). The oxygen isotope ratios of analyzed chondrules all plot very close to the primitive chondrule minerals (PCM) line. In each of 24 chondrules, the olivine and/or pyroxene grains analyzed show indistinguishable oxygen isotope ratios. Exceptions are minor occurrences of isotopically distinguished relict olivine grains, which were found in nine chondrules. The isotope homogeneity of these phenocrysts is consistent with a co-magmatic crystallization of olivine and pyroxene from the final chondrule melts and a significant oxygen isotope exchange between the ambient gas and the melts. Homogeneous type I chondrules with Mg#'s of 98.9-99.5 have host chondrule Δ17O values ranging from -6.0‰ to -4.1‰, with one exception (Δ17O: -1.2‰; Mg#: 99.6). Homogeneous chondrules with Mg#'s poor H2O ice (∼0.3-0.4× the CI dust; Δ17O > 0‰) and at dust enrichments of ∼300-2000×. Regarding the Mg# and oxygen isotope ratios, the chondrule populations sampled by CM and CO chondrites are similar and indistinguishable. The similarity of these 16O-rich components in CO and CM chondrites is also supported by the common Fe/Mn ratio of olivine in type II chondrules. Although they accreted similar high-temperature silicates, CO chondrites are anhydrous compared to CM chondrites, suggesting they derived from different parent bodies formed inside and outside the snow line, respectively. If chondrules in CO and CM chondrites formed at the same disk locations but the CM parent body accreted later than the CO parent body, the snow line might have crossed the common chondrule-forming region towards the Sun between the time of the CO and CM parent bodies accretion.

  9. What we know about Oslo meteorite from cosmogenic isotope analysis

    Science.gov (United States)

    Tymiński, Z.; Stolarz, M.; Kubalczak, T.; Zaręba, P.; Burski, M.; Bilet, M.; Miśta, E.; Tymińska, K.; Kołakowska, E.; Burakowska, A.; Żołądek, P.; Olech, A.; Wiśniewski, M.; Listkowska, A.; Saganowski, P.

    2015-10-01

    The fragments of an asteroid that had crashed over Norway were found in a few locations in Oslo at the beginning of March 2012. Later on some pieces of meteorite from the most South area were collected by the Meteoritical Section members of Comet and Meteor Workshop (PKiM) with the help of local meteoritical authorities. One meteorite fragment of 32g was used to measure cosmogenic radionuclides using non-destructive high-resolution gamma spectrometry technique. Five radioisotopes such as Al-26, Na-22, Mn-54, Co-57 and Co-60 were detected

  10. 243Cm half-life determinaton

    International Nuclear Information System (INIS)

    Timofeev, G.A.; Kalygin, V.V.; Privalova, P.A.

    1986-01-01

    By molar ratios of 243 Cm mixture with 244 Cm and Pu nuclides formed as a result of Cm nuclides α-decay the 243 Cm half-life T α243 is determined. The 244 Cm half-life is measured earlier with high accuracy. The 243 Cm/ 244 Cm ratio measured by means of a mass spectrometer equals 0.989+-0.004. The obtained value T α243 =29.20+-0.14 years

  11. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

    Science.gov (United States)

    Slobodkin, Alexander; Gavrilov, Sergey; Ionov, Victor; Iliyin, Vyacheslav

    2015-01-01

    One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

  12. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

    Directory of Open Access Journals (Sweden)

    Alexander Slobodkin

    Full Text Available One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite. After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

  13. Carbon isotope composition of individual amino acids in the Murchison meteorite

    International Nuclear Information System (INIS)

    Engel, M.H.; Macko, S.A.; Silter, J.A.

    1996-01-01

    A SIGNIFICANT parties of prebiotic organic matter on the early Earth may have been introduced by carbonaceous asteroids and comets. 1 The distribution and stable-isotope composition of individual organic compounds in carbonaceous meteorites, which are thought to be derived from asteroidal parent bodies, may therefore provide important information concerning mechanistic pathways for prebiotic synthesis 2 and the composition of organic matter on Earth before living systems developed. 3 Previous studies 11,12 have shown that meteorite amino acids are enriched in 13 C relatives to their terrestrial counterparts, but individual species were not distinguished. Here we report the 13 C contents of individual amino acids in the Murchison meteorite. The amino acids are enriched in 13 C, indicating an extraterrestrial origin. Alanine is not racemic, and the 13 C enrichment of its D- and L-enantiomers implies that the excess of the L-enantiomer is indigenous rather than terrestrial contamination, suggesting that optically active materials were present in the early Solar System before life began. copyright 1996 American Institute of Physics

  14. A large planetary body inferred from diamond inclusions in a ureilite meteorite.

    Science.gov (United States)

    Nabiei, Farhang; Badro, James; Dennenwaldt, Teresa; Oveisi, Emad; Cantoni, Marco; Hébert, Cécile; El Goresy, Ahmed; Barrat, Jean-Alix; Gillet, Philippe

    2018-04-17

    Planetary formation models show that terrestrial planets are formed by the accretion of tens of Moon- to Mars-sized planetary embryos through energetic giant impacts. However, relics of these large proto-planets are yet to be found. Ureilites are one of the main families of achondritic meteorites and their parent body is believed to have been catastrophically disrupted by an impact during the first 10 million years of the solar system. Here we studied a section of the Almahata Sitta ureilite using transmission electron microscopy, where large diamonds were formed at high pressure inside the parent body. We discovered chromite, phosphate, and (Fe,Ni)-sulfide inclusions embedded in diamond. The composition and morphology of the inclusions can only be explained if the formation pressure was higher than 20 GPa. Such pressures suggest that the ureilite parent body was a Mercury- to Mars-sized planetary embryo.

  15. Asteroid 2008 TC3 Breakup and Meteorite Fractions

    Science.gov (United States)

    Goodrich, C.; Jenniskens, P.; Shaddad, M. H.; Zolensky, M. E.; Fioretti, A. M.

    2017-01-01

    The recovery of meteorites from the impact of asteroid 2008 TC3 in the Nubian Desert of Sudan on October 7, 2008, marked the first time meteorites were collected from an asteroid observed in space by astronomical techniques before impacting. Search teams from the University of Khartoum traced the location of the strewn field and collected about 660 meteorites in four expeditions to the fall region, all of which have known fall coordinates. Upon further study, the Almahata Sitta meteorites proved to be a mixed bag of mostly ureilites (course grained, fine grained, and sulfide-metal assemblages), enstatite chondrites (EL3-6, EH3, EH5, breccias) and ordinary chondrites (H5-6, L4-5). One bencubbinite-like carbonaceous chondrite was identified, as well as one unique Rumuruti-like chondrite and an Enstatite achondrite. New analysis: The analysed meteorites so far suggest a high 30-40 percent fraction of non-ureilites among the recovered samples, but that high fraction does not appear to be in agreement with the meteorites in the University of Khartoum (UoK) collection. Ureilites dominate the meteorites that were recovered by the Sudanese teams. To better understand the fraction of recovered materials that fell to Earth, a program has been initiated to type the meteorites in the UoK collection in defined search areas. At this meeting, we will present some preliminary results from that investigation.

  16. The enrichment of the ISM: Evolved stars and meteorites

    Science.gov (United States)

    Jura, M.

    1995-01-01

    Small inclusions (diameters ranging from 0.001 microns to 10 microns) of isotopically anomalous material within meteorites were almost certainly produced in mass-losing stars. These solid particles preserved their individual identities as they passed through the interstellar medium and the pre-solar nebular. The relationship between studies of meteorites and mass-losing red giants is explored.

  17. An Anomalous Basaltic Meteorite from the Innermost Main Belt

    Czech Academy of Sciences Publication Activity Database

    Bland, P.A.; Spurný, Pavel; Towner, M.C.; Bevan, A.W.R.; Singleton, A.T.; Bottke jr., W.F.; Greenwood, R.C.; Chesley, S.R.; Shrbený, Lukáš; Borovička, Jiří; Ceplecha, Zdeněk; McClafferty, T.; Vaughan, D.; Benedix, G.K.; Deacon, G.; Howard, K.T.; Franchi, I.A.; Hough, R.M.

    2009-01-01

    Roč. 325, č. 5947 (2009), s. 1525-1527 ISSN 0036-8075 R&D Projects: GA ČR GA205/08/0411 Institutional research plan: CEZ:AV0Z10030501 Keywords : meteorites * meteorite fall Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 29.747, year: 2009

  18. Inaugeral lecture - Meteorite impacts on Earth and on the Earth ...

    African Journals Online (AJOL)

    There is some controversial evidence for the theory that the first life on Earth itself may have been transported here on meteorites from Mars. The possibility of a major meteorite impact on Earth in the near future emphasizes the dramatic nature of these recent discoveries, which are having deep impacts in the Earth sciences ...

  19. Meteorite Falls Observed by the Desert Fireball Network: An Update

    Czech Academy of Sciences Publication Activity Database

    Bland, P.A.; Spurný, Pavel; Shrbený, Lukáš; Towner, M.C.; Bevan, A.W.R.; Borovička, Jiří; McClafferty, T.; Vaughan, D.

    2010-01-01

    Roč. 45, Supplement (2010), A16-A16 ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /73./. 26.07.2010-30.07.2010, New York] Institutional research plan: CEZ:AV0Z10030501 Keywords : meteorite falls Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  20. Timescales and settings for alteration of chondritic meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Krot, A N; Hutcheon, I D; Brearley, A J; Pravdivtseva, O V; Petaev, M I; Hohenberg, C M

    2005-11-16

    Most groups of chondritic meteorites experienced diverse styles of secondary alteration to various degrees that resulted in formation of hydrous and anhydrous minerals (e.g., phyllosilicates, magnetite, carbonates, ferrous olivine, hedenbergite, wollastonite, grossular, andradite, nepheline, sodalite, Fe,Ni-carbides, pentlandite, pyrrhotite, Ni-rich metal). Mineralogical, petrographic, and isotopic observations suggest that the alteration occurred in the presence of aqueous solutions under variable conditions (temperature, water/rock ratio, redox conditions, and fluid compositions) in an asteroidal setting, and, in many cases, was multistage. Although some alteration predated agglomeration of the final chondrite asteroidal bodies (i.e. was pre-accretionary), it seems highly unlikely that the alteration occurred in the solar nebula, nor in planetesimals of earlier generations. Short-lived isotope chronologies ({sup 26}Al-{sup 26}Mg, {sup 53}Mn-{sup 53}Cr, {sup 129}I-{sup 129}Xe) of the secondary minerals indicate that the alteration started within 1-2 Ma after formation of the Ca,Al-rich inclusions and lasted up to 15 Ma. These observations suggest that chondrite parent bodies must have accreted within the first 1-2 Ma after collapse of the protosolar molecular cloud and provide strong evidence for an early onset of aqueous activity on these bodies.

  1. Neutron activation analysis of aluminium, silicon, manganese and iron in stone meteorites

    International Nuclear Information System (INIS)

    Abdusalyamov, N.; Mirzaev, M.R.; Murtazin, O.G.

    1973-01-01

    The paper describes a method which relies on nuclear reactions involving fast neutrons. Samples weighing 1x10 -3 -1x10 -2 g are irradiated together with calibrated standards in a reactor channel under a flux of 1.8x10 13 n/cm 2 sec for 1 min. The activities are measured on an AI-100 analyser with a 40x40 NaI (Tl) crystal. Ten samples can be handled in three hours. The method has been used for analysing seven different meteorites, and also for single crystals and pure materials. (author)

  2. Absolute isotopic abundances of Ti in meteorites

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.; Wasserburg, G.J.

    1985-01-01

    The absolute isotope abundance of Ti has been determined in Ca-Al-rich inclusions from the Allende and Leoville meteorites and in samples of whole meteorites. The absolute Ti isotope abundances differ by a significant mass dependent isotope fractionation transformation from the previously reported abundances, which were normalized for fractionation using 46 Ti/ 48 Ti. Therefore, the absolute compositions define distinct nucleosynthetic components from those previously identified or reflect the existence of significant mass dependent isotope fractionation in nature. We provide a general formalism for determining the possible isotope compositions of the exotic Ti from the measured composition, for different values of isotope fractionation in nature and for different mixing ratios of the exotic and normal components. The absolute Ti and Ca isotopic compositions still support the correlation of 50 Ti and 48 Ca effects in the FUN inclusions and imply contributions from neutron-rich equilibrium or quasi-equilibrium nucleosynthesis. The present identification of endemic effects at 46 Ti, for the absolute composition, implies a shortfall of an explosive-oxygen component or reflects significant isotope fractionation. Additional nucleosynthetic components are required by 47 Ti and 49 Ti effects. Components are also defined in which 48 Ti is enhanced. Results are given and discussed. (author)

  3. 48Ca HETEROGENEITY IN DIFFERENTIATED METEORITES

    International Nuclear Information System (INIS)

    Chen, Hsin-Wei; Lee, Typhoon; Lee, Der-Chuen; Shen, Jason Jiun-San; Chen, Jiang-Chang

    2011-01-01

    Isotopic heterogeneities of 48 Ca have been found in numerous bulk meteorites that are correlated with 50 Ti and 54 Cr anomalies among differentiated planetary bodies, and the results suggest that a rare subset of neutron-rich Type Ia supernova (nSN Ia) was responsible for contributing these neutron-rich iron-group isotopes into the solar system (SS). The heterogeneity of these isotopes found in differentiated meteorites indicates that the isotopic compositions of the bulk SS are not uniform, and there are significant amounts of nSNe Ia dust incompletely mixed with the rest of SS materials during planetary formation. Combined with the data of now-extinct short-lived nuclide 60 Fe, which can be produced more efficiently from an nSN Ia than a Type II supernova ejecta, the observed planetary-scale isotopic heterogeneity probably reflects a late input of stellar dust grains with neutron-rich nuclear statistical equilibrium nuclides into the early SS.

  4. X-radiography of slices of the Allende Meteorite

    Science.gov (United States)

    Smith, M. J.; Anderson, J. B.; Heymann, D.

    1984-01-01

    A 2.2 kg fragment of the Allende Meteorite was derinded and sliced by bandsawing. Several X-radiographs were made of all slices. The following features are resolved: grains of blocky troilite (bright spots), troilite rimmed chondrules (bright halos), chondrules with central vugs (dim halos), white aggregates (dark patches), and dark inclusions (medium dark patches). The number of FeS grains larger than about 0.5 mm is one per 6 + or - 1 gram of this fragment. Their concentration appears to be uniform at the 1 kg weight level, but is not uniform at the 100 g level. The number of FeS rimmed chondrules is one per 10 g. Their concentration is also nonuniform at the 100 g weight level. The number of white aggregates is roughly one per 20 g. These disc shaped objects show a distinct preferred orientation of the axis orthogonal to the plane of the disc. Chondrules with central vugs are numerous. Linear and curved arrays of chondrules, up to a few cm long, were observed. An interpretation of the observed features is given.

  5. Microbial Populations of Stony Meteorites: Substrate Controls on First Colonizers

    Directory of Open Access Journals (Sweden)

    Alastair W. Tait

    2017-06-01

    Full Text Available Finding fresh, sterilized rocks provides ecologists with a clean slate to test ideas about first colonization and the evolution of soils de novo. Lava has been used previously in first colonizer studies due to the sterilizing heat required for its formation. However, fresh lava typically falls upon older volcanic successions of similar chemistry and modal mineral abundance. Given enough time, this results in the development of similar microbial communities in the newly erupted lava due to a lack of contrast between the new and old substrates. Meteorites, which are sterile when they fall to Earth, provide such contrast because their reduced and mafic chemistry commonly differs to the surfaces on which they land; thus allowing investigation of how community membership and structure respond to this new substrate over time. We conducted 16S rRNA gene analysis on meteorites and soil from the Nullarbor Plain, Australia. We found that the meteorites have low species richness and evenness compared to soil sampled from directly beneath each meteorite. Despite the meteorites being found kilometers apart, the community structure of each meteorite bore more similarity to those of other meteorites (of similar composition than to the community structure of the soil on which it resided. Meteorites were dominated by sequences that affiliated with the Actinobacteria with the major Operational Taxonomic Unit (OTU classified as Rubrobacter radiotolerans. Proteobacteria and Bacteroidetes were the next most abundant phyla. The soils were also dominated by Actinobacteria but to a lesser extent than the meteorites. We also found OTUs affiliated with iron/sulfur cycling organisms Geobacter spp. and Desulfovibrio spp. This is an important finding as meteorites contain abundant metal and sulfur for use as energy sources. These ecological findings demonstrate that the structure of the microbial community in these meteorites is controlled by the substrate, and will not

  6. The Okhansk Meteorite: Specifics of Composition, Structure, and Genesis

    Directory of Open Access Journals (Sweden)

    A.I. Bakhtin

    2016-12-01

    Full Text Available The Okhansk meteorite fell on August 18, 1887 near the village of Tabor, about 15 km away from the town of Okhansk in Perm province and weighed 186.5 kg (the total weight of collected fragments, according to P.I. Krotov, was more than 245 kg. The shock wave from the meteorite entry knocked down animals and riders on horses. Despite the fact that it was significantly stronger than that caused by the Chelyabinsk meteorite of 2013, all information about this meteorite has completely erased from people's memory. It has been shown that the meteorite is an ordinary olivine-bronzite chondrite. Its main silicate minerals are olivine, bronzite, plagioclase, and diopside. The main ore minerals are kamacite and troilite. The meteorite contains silicate glass in large amounts. The analysis of the composition and structure of the Okhansk meteorite has demonstrated that it was formed at the early stages of accretion of the melted substance of the protosolar nebula without undergoing endogenous, temperature, or pressure changes.

  7. Nuclear tracks in the Angra dos Reis and Moore County meteorites

    International Nuclear Information System (INIS)

    Carver, E.A.; Anders, E.

    1976-01-01

    Charged particle tracks were studied in the Angra dos Reis and Moore County meteorites, both of which contain an unexplained excess of He 4 . A selective annealing method was used to resolve cosmic-ray tracks from fission tracks. It gave the following cosmic-ray and fission-track densities, in units of 10 6 cm -2 : Angra dos Reis 1.3 to 4.4 and 7.8; Moore Co. feldspar 1.9 to 3.0 and 0.51; Moore Co. pigeonite 2.0 to 2.9 and 0.078 to 0.35. The fission-track densities are 10 to 100 times higher than expected from U 238 ; the excess is probably due to extinct Pu 244 . The Pu 244 /U 238 ratios at the start of track retention were 0.003 for Angra dos Reis and 0.002 to 0.03 got Moore Co. No evidence was found for fission tracks attributable to the unknown progenitor of excess He 4 in these meteorites; the fission branch of this progenitor comprises less than 10 -5 the α-branch. A search for pleochroic halos also gave negative results. The preatmospheric radii of the two meteorites are >= 13 and >= 7 cm. According to meteor theory, this implies geocentric velocities of >19 and >= 6 km/sec. The etching behaviour of Angra dos Reis augite is highly anomalous, giving rise to spurious angular anisotropies and skewed length distributions. This confirms similar observation by Fleischer et al (Proc. Apollo II Lunar Sci. Conf. Geochem. Cosmochim. Acta Suppl.; 1:2103 (1970)) on lunar augite. (author)

  8. Ion irradiation of the Murchison meteorite: Visible to mid-infrared spectroscopic results

    Science.gov (United States)

    Lantz, C.; Brunetto, R.; Barucci, M. A.; Dartois, E.; Duprat, J.; Engrand, C.; Godard, M.; Ledu, D.; Quirico, E.

    2015-05-01

    Aims: The goal of this study is to simulate space weathering processes on primitive bodies. We use ion implantation as a simulation of solar wind irradiation, which has been suggested by several authors to be the major component of space weathering on main belt asteroids. The laboratory analogs we irradiate and analyze are carbonaceous chondrites; we started the study with the Allende CV meteorite and in this companion paper we present results on the Murchison CM meteorite. Methods: We performed irradiations on pressed pellets of Murchison with 40 keV He+ and Ar+ ions using fluences up to 3 × 1016 ions/cm2. Reflectance spectra were acquired ex situ before and after irradiation in the visible to mid-infrared range (0.4-16 μm). A Raman analysis was also performed to investigate the modifications of the aromatic carbonaceous component. Results: Our results indicate that spectral variations after irradiation within the visible range are smaller than spectral variations due to sample grain size or viewing geometry of the Murchison meteorite. The aqueous alteration band profile near 3 μm changes after irradiation, as adsorbed water is removed, and phyllosilicates are affected. Raman spectroscopy highlights the insoluble organic matter (IOM) modification under irradiation. We observe a shift of the silicates band at 9.9 μm, probably due to a preferential loss of Mg (compared to Fe, the lighter Mg is more easily sputtered backward) and/or amorphization of Mg-rich materials. We compare our results to previous experiments on organic-rich materials (like asphaltite or carbonaceous chondrites), and on ordinary chondrites and olivine grains. We find that the reddening/darkening trend observed on silicate-rich surfaces is not valid for all carbonaceous chondrites, and that the spectral modifications after irradiation are a function of the initial albedo.

  9. Evidence for methane in Martian meteorites.

    Science.gov (United States)

    Blamey, Nigel J F; Parnell, John; McMahon, Sean; Mark, Darren F; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R M; Banerjee, Neil R; Flemming, Roberta L

    2015-06-16

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity.

  10. Radioactivity of the moon, planets, and meteorites

    Science.gov (United States)

    Surkou, Y. A.; Fedoseyev, G. A.

    1977-01-01

    Analytical data is summarized for the content of natural radioactive elements in meteorites, eruptive terrestrial rocks, and also in lunar samples returned by Apollo missions and the Luna series of automatic stations. The K-U systematics of samples analyzed in the laboratory are combined with data for orbital gamma-ray measurements for Mars (Mars 5) and with the results of direct gamma-ray measurements of the surface of Venus by the Venera 8 lander. Using information about the radioactivity of solar system bodies and evaluations of the content of K, U, and Th in the terrestrial planets, we examine certain aspects of the evolution of material in the protoplanetary gas-dust cloud and then in the planets of the solar system.

  11. Anomalous krypton in the Allende meteorite

    Science.gov (United States)

    Frick, U.

    1977-01-01

    The reported investigation provides important new data for the heavy noble gases, especially Kr, in the Allende meteorite. The data are used to criticize the original model of Lewis et al. (1975) based on the noble gas data of these researchers. The conclusions reached in the investigation support alternative models which have been mainly based on Xe data by Lewis et al. (1975, 1977). Because of the relatively high noble gas abundances in the separates studied, disturbance from nuclear effects occurring in situ such as spallation and neutron capture is insignificant, offering an opportunity to study primordial Ar, Kr, and Xe. The isotopic and abundance data obtained from the samples largely confirm the noble gas results of Lewis et al. (1975, 1977) where isotopic correlations agree with the correlations of the considered samples. It is found that both Kr and Xe data are consistent with a two component mixture of 'ordinary' as well as 'anomalous' planetary gases.

  12. The Importance of Meteorite Collections to Sample Return Missions: Past, Present, and Future Considerations

    Science.gov (United States)

    Welzenbach, L. C.; McCoy, T. J.; Glavin, D. P.; Dworkin, J. P.; Abell, P. A.

    2012-01-01

    While much of the scientific community s current attention is drawn to sample return missions, it is the existing meteorite and cosmic dust collections that both provide the paradigms to be tested by these missions and the context for interpreting the results. Recent sample returns from the Stardust and Hayabusa missions provided us with new materials and insights about our Solar System history and processes. As an example, Stardust sampled CAIs among the population of cometary grains, requiring extensive and unexpected radial mixing in the early solar nebula. This finding would not have been possible, however, without extensive studies of meteoritic CAIs that established their high-temperature, inner Solar System formation. Samples returned by Stardust also revealed the first evidence of a cometary amino acid, a discovery that would not have been possible with current in situ flight instrument technology. The Hayabusa mission provided the final evidence linking ordinary chondrites and S asteroids, a hypothesis that developed from centuries of collection and laboratory and ground-based telescopic studies. In addition to these scientific findings, studies of existing meteorite collections have defined and refined the analytical techniques essential to studying returned samples. As an example, the fortuitous fall of the Allende CV3 and Murchison CM2 chondrites within months before the return of Apollo samples allowed testing of new state-of-the-art analytical facilities. The results of those studies not only prepared us to better study lunar materials, but unanticipated discoveries changed many of our concepts about the earliest history and processes of the solar nebula. This synergy between existing collections and future space exploration is certainly not limited to sample return missions. Laboratory studies confirmed the existence of meteorites from Mars and raised the provocative possibility of preservation of ancient microbial life. The laboratory studies in

  13. Isotopic Evidence for Multi-stage Cosmic-ray Exposure Histories of Lunar Meteorites: Long Residence on the Moon and Short Transition to the Earth

    International Nuclear Information System (INIS)

    Hidaka, Hiroshi; Sakuma, Keisuke; Nishiizumi, Kunihiko; Yoneda, Shigekazu

    2017-01-01

    It is known that most lunar meteorites have complicated cosmic-ray exposure experiences on the Moon and in space. In this study, cosmic-ray irradiation histories of six lunar meteorites, Dhofar 489, Northwest Africa 032 (NWA 032), NWA 479, NWA 482, NWA 2995, and NWA 5000, were characterized from neutron-captured isotopic shifts of Sm and Gd, and from the abundances of long-lived cosmogenic radionuclides like 10 Be, 26 Al, 36 Cl, and 41 Ca. Sm and Gd isotopic data of all of six meteorites show significant isotopic shifts of 149 Sm– 150 Sm and 157 Gd– 158 Gd caused by accumulation of neutron capture reactions due to cosmic-ray irradiation, corresponding to the neutron fluences of (1.3–9.6) × 10 16 n cm −2 . In particular, very large Sm and Gd isotopic shifts of NWA 482 are over those of a lunar regolith 70002, having the largest isotopic shifts among the Apollo regolith samples, corresponding to cosmic-ray exposure duration over 800 million years in the lunar surface (2 π irradiation). Meanwhile, the concentrations of cosmogenic radionuclides for individual six meteorites show the short irradiation time less than one million years as their bodies in space (4 π irradiation). Our data also support the results of previous studies, revealing that most of lunar meteorites have long exposure ages at shallow depths on the Moon and short transit times from the Moon to the Earth.

  14. The role of population in tracking meteorite falls in Africa

    Science.gov (United States)

    Khiri, F.; Ibhi, A.; Saint-Gerant, T.; Medjkane, M.; Ouknine, L.

    2016-01-01

    The 158 African meteorite falls recorded during the period 1801 to 2014, account for more than 12.3% of all meteorite falls known from the world. Their rate is variable in time and in space. The number of falls continues to grow since 1860. They are concentrated in countries which exhibit large population (mainly rural population) with an uniform distribution. Generally, the number of falls follows the increase of the population density (coefficient of correlation r = 0.98). The colonial phenomenon, the education of population in this field, the population lifestyle and the rural exodus, are also factors among others which could explain the variability of the recovery of meteorite falls in Africa. In this note, we try by a statistical study, to examine the role of the African population in tracking meteorite falls on this continent.

  15. Meteorite-catalyzed synthesis of nucleosides and other prebiotic compounds

    Czech Academy of Sciences Publication Activity Database

    Ferus, Martin; Knížek, Antonín; Civiš, Svatopluk

    2015-01-01

    Roč. 112, č. 23 (2015), s. 7109-7110 ISSN 0027-8424 Institutional support: RVO:61388955 Keywords : meteorite-catalzzed synthesis * nucleosides * prebiotic compounds Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 9.423, year: 2015

  16. The Effect of Aqueous Alteration on Primordial Noble Gases in CM Chondrites

    Science.gov (United States)

    Weimer, D.; Busemann, H.; Alexander, C. M. O'D.; Maden, C.

    2017-07-01

    We have analyzed 32 CM chondrites for their noble gas contents and isotopic compositions and calculated CRE ages. Correlated effects of parent body aqueous alteration with primordial noble gas contents were detected.

  17. Historical Romanian meteorites: emendations of official catalogue records

    Directory of Open Access Journals (Sweden)

    Dana Lüttge-Pop

    2013-12-01

    Full Text Available With its more than 50,000 valid official and provisory meteorite entries, the online catalogue of The Meteoritical Society, i.e., the Meteoritical Bulletin Database (MBDB represents the most authorized and primary source of information in the field. Unfortunately, this official reference contains some erroneous geographical information in the case of five historical Romanian meteorites. For Zsadany, the current country information is “Hungary, Bekes county” instead of Romania, Timiş County. For Mezö-Madaras and Tauti, the county affiliations “Harghita” and respectively “Cluj” have to be corrected into Mureş and Arad, respectively. Geographical coordinates for Kakowa and Ohaba require minor corrections, only. The source of these errors resides in changes of names and administrative affiliations of the localities of the fall/find, while the formal nomenclature protocol requires the meteorite name in the original description to be preserved. The example of the historical Romanian meteorites illustrates the challenges that a researcher unfamiliar with a region faces when locating old specimens, in general. This requires knowledge of regional history and geography, and sometimes access to the original references - usually not written in English, or having a somehow limited circulation. Additionally, in the last two decades several new publications provided more detailed classification information on Sopot, Ohaba, Tauti and Mocs meteorites. Sopot was classified as H5, with shock stage S3. The studied Ohaba and Tauti samples also attested S3 shock stages. Variable shock stages (S3-5 were identified in Mocs samples, the most well-known Romanian meteorite. This new information should be added to the corresponding MBDB entries.

  18. Noble gases in ten stone meteorites from Antarctica

    International Nuclear Information System (INIS)

    Weber, H.W.; Schultz, L.

    1980-01-01

    The concentrations and isotopic composition of noble gases have been determined in all ten stone meteorites recovered in Antarctica during 1976-1977 by a U.S.-Japanese expedition. From a comparison of spallogenic and radiogenic gas components it is concluded that the chondrites Mt. Baldr (a) and Mt. Baldr (b) belong to the same fall but that all other stone meteorites are individual finds. (orig.)

  19. Methods for determining the preatmospheric dimensions of meteorites

    Science.gov (United States)

    Ustinova, G. K.; Alekseev, V. A.; Lavrukhina, A. K.

    1988-10-01

    Methods are proposed for the determination of the preatmospheric size of a meteorite on the basis of data on its cosmogenic radionuclides. Optimal conditions for the application of each of these methods are presented together with the demonstration of their effectiveness. Estimates of relative dimensions determined by these methods are presented for the Harleton, St. Severin, Lost City, Peace River, Pribram, Dhajala, Innisfree, Bruderheim, Ehole, and Gorlovka chondrites and for the Iardymly, Boguslavka, Treysa, and Sikhote-Alin' iron meteorites.

  20. U-Pb studies of the Appley Bridge meteorite

    International Nuclear Information System (INIS)

    Gale, N.H.; Arden, J.W.; Hutchinson, R.

    1979-01-01

    The U and Pb concentration in samples from the interior of the 10.9 kg stone BM 1920, 40 (British Museum), the isotopic composition of lead, a lead-lead diagram for whole meteorite samples of Appley Bridge, and a U-Pb concordia diagram for whole meteorite samples of Appley Bridge from different measurements are treated. (HK) 891 HK/HK 892 MB [de

  1. Ancient stardust in meteorites - A new source of cosmic material

    International Nuclear Information System (INIS)

    Walker, Robert M.

    2000-01-01

    Micron sized, presolar grains of SiC and graphite (as well as other phases not discussed here) found in mineral separates of primitive meteorites constitute a new source of cosmic material. The grains are identified by anomalous isotopic ratios in both major and minor elements. In some cases, these differ from average solar system values by a factor >10 3 . The SiC grains can be separated into distinct isotopic families representing different stellar sources. Only two types are discussed here - 'mainstream' SiC grains, constituting ∼98% of the total and less abundant X-grains that constitute <1% of the total. The former have isotopic ratios characteristic of S-process nucleosynthesis and are believed to be condensates formed in the atmospheres of AGB stars. In contrast, X grains have isotopic patterns characteristic of R-process nucleosynthesis and are believed to be supernovae condensates. In addition to giving a wealth of new detail on the nuclear processes in different stars, the grains open up entirely new avenues of research. For example, electron microscope mineralogical/petrographic studies of microtomed grains give insight on the processes of grain growth. Molecules of polycyclic aromatic hydrocarbons (PAHs) are common in the graphite grains. Isotopic measurements demonstrate that some of the PAHs formed from the same suite of atoms as the parent grains and are thus indigenous. The relationship of presolar grains to cosmic ray physics is briefly considered. Overall, the grain work serves to deepen the mystery of the similarity of isotopic ratios measured in cosmic rays to those of Solar System materials

  2. Lunar and Planetary Science XXXV: Astrobiology Stew: Pinch of Microbes, Smidgen of UV, Touch of Organics, and Dash of Meteorites

    Science.gov (United States)

    2004-01-01

    The session Astrobiology Stew: Pinch of Microbes, Smidgen of UV, Touch of Organics, and Dash of Meteorites includes the following topics: 1) Investigating the Impact of UV Radiation on High-Altitude Shallow Lake Habitats, Life Diversity, and Life Survival Strategies: Clues for Mars' Past Habitability Potential? 2) An Analysis of Potential Photosynthetic Life on Mars; 3) Radiation Inactivation of Bacterial spores on Mars; 4) Hydrophobic Surfaces of Spacecraft Components Enhance the Aggregation of Microorganisms and May Lead to Higher Survival Rates of Bacteria on Mars Landers; 5) Optical Detection of Organic Chemical Biosignatures at Hydrothermal Vents; 6) Signs of Life in Meridiani Planum-What Might Opportunity See (or Miss)? 7) Isolation of PUrines and Pyrimidines from the Murchison Meteorite Using Sublimation; and 8) Relative Amino Acid Composition of CM1 Carbonaceous Chondrites.

  3. Obtaining Magnetic Properties of Meteorites Using Magnetic Scanner

    Science.gov (United States)

    Kletetschka, G.; Nabelek, L.; Mazanec, M.; Simon, K.; Hruba, J.

    2015-12-01

    Magnetic images of Murchison meteorite's and Chelyabinsk meteorite's thin section have been obtained from magnetic scanning system from Youngwood Science and Engineering (YSE) capable of resolving magnetic anomalies down to 10-3 mT range from about 0.3 mm distance between the probe and meteorite surface (resolution about 0.15 mm). Anomalies were produced repeatedly, each time after application of magnetic field pulse of varying amplitude and constant, normal or reversed, direction. This process resulted in both magnetizing and demagnetizing of the meteorite thin section, while keeping the magnetization vector in the plane of the thin section. Analysis of the magnetic data allows determination of coercivity of remanence (Bcr) for the magnetic sources in situ. Value of Bcr is critical for calculating magnetic forces applicable during missions to asteroids where gravity is compromised. Bcr was estimated by two methods. First method measured varying dipole magnetic field strength produced by each anomaly in the direction of magnetic pulses. Second method measured deflections of the dipole direction from the direction of magnetic pulses (Nabelek et al., 2015). Nabelek, L., Mazanec, M., Kdyr, S., and Kletetschka, G., 2015, Magnetic, in situ, mineral characterization of Chelyabinsk meteorite thin section: Meteoritics & Planetary Science.

  4. Kr and Xe isotopes from spontaneous fission of 248Cm and 250Cf

    International Nuclear Information System (INIS)

    Srinivasan, B.

    1980-01-01

    Relative yields of Kr and Xe isotopes from the spontaneous fission of 248 Cm and 250 Cf have been determined mass spectrometrically. The yields are as follows: 83 Kr/ 84 Kr/ 85 Kr/ 86 Kr = 0.223/0.458/0.596/ identical 1.00 and 0.306/0.582/0.793/ identical 1.00; 131 Xe/ 134 Xe/ 136 Xe = 0.486/0.819/1.075 identical 1.00 and 0.343/0.506/0.851/ identical 1.00 from 248 Cm and 250 Cf, respectively. The Xe yields from 248 Cm agree with an earlier determination by Leich et al. Neither of these yield patterns matches that of fissiogenic Kr and Xe in carbonaceous chondrites and hence 248 Cm and 250 Cf are ruled out as progenitors of the meteoritic Kr and Xe. In general, none of the spontaneously fissioning nuclides of actinide elements can be identified as a possible progenitor. Even the mixtures of actinides, including a combination of 248 Cm and 250 Cm, are unsuitable. The origin of anomalous Kr and Xe in carbonaceous chondrites must then be traced either to the spontaneous fission of a superheavy element or to peculiarities in specific nucleosynthetic reactions. (orig.)

  5. Revealing the sub-nanometere three-dimensional microscture of a metallic meteorite

    Science.gov (United States)

    Einsle, J. F.; Harrison, R.; Blukis, R.; Eggeman, A.; Saghi, Z.; Martineau, B.; Bagot, P.; Collins, S. M.; Midgley, P. A.

    2017-12-01

    Coming from from the core of differentiated planetesimals, iron-nickel meteorites provide some of the only direct material artefacts from planetary cores. Iron - nickel meteorites contain a record of their thermal and magnetic history, written in the intergrowth of iron-rich and nickel-rich phases that formed during slow cooling over millions of years. Of intense interest for understanding the thermal and magnetic history is the `'cloudy zone''. This nanoscale intergrowth that has recently been used to provide a record of magnetic activity on the parent body of stony-iron meteorites. The cloudy zone consists of islands of tetrataenite surrounded by a matrix phase, Here we use a multi-scale and multidimensional comparative study using high-resolution electron diffraction, scanning transmission electron tomography with chemical mapping, atom probe tomography and micromagnetic simulations to reveal the three-dimensional architecture of the cloudy zone with sub-nanometre spatial resolution. Machine learning data deconvolution strategies enable the three microanalytical techniques to converge on a consistent microstructural description for the cloudy zone. Isolated islands of tetrataenite are found, embedded in a continuous matrix of an FCC-supercell of Fe27Ni5 structure, never before identified in nature. The tetrataenite islands are arranged in clusters of three crystallographic variants, which control how magnetic information is encoded into the nanostructure during slow cooling. The new compositional, crystallographic and micromagnetic data have profound implications for how the cloudy zone acquires magnetic remanence, and requires a revision of the low-temperature metastable phase diagram of the Fe-Ni system. This can lead to a refinement of core dynamics in small planetoids.

  6. Carbonaceous Chondrite Meteorites: the Chronicle of a Potential Evolutionary Path between Stars and Life.

    Science.gov (United States)

    Pizzarello, Sandra; Shock, Everett

    2017-09-01

    The biogenic elements, H, C, N, O, P and S, have a long cosmic history, whose evolution can still be observed in diverse locales of the known universe, from interstellar clouds of gas and dust, to pre-stellar cores, nebulas, protoplanetary discs, planets and planetesimals. The best analytical window into this cosmochemical evolution as it neared Earth has been provided so far by the small bodies of the Solar System, some of which were not significantly altered by the high gravitational pressures and temperatures that accompanied the formation of larger planets and may carry a pristine record of early nebular chemistry. Asteroids have delivered such records, as their fragments reach the Earth frequently and become available for laboratory analyses. The Carbonaceous Chondrite meteorites (CC) are a group of such fragments with the further distinction of containing abundant organic materials with structures as diverse as kerogen-like macromolecules and simpler compounds with identical counterparts in Earth's biosphere. All have revealed a lineage to cosmochemical synthetic regimes. Several CC show that asteroids underwent aqueous alteration of their minerals or rock metamorphism but may yet yield clues to the reactivity of organic compounds during parent-body processes, on asteroids as well as larger ocean worlds and planets. Whether the exogenous delivery by meteorites held an advantage in Earth's molecular evolution remains an open question as many others regarding the origins of life are. Nonetheless, the natural samples of meteorites allow exploring the physical and chemical processes that might have led to a selected chemical pool amenable to the onset of life. Graphical Abstract ᅟ.

  7. Styding of meteorites of Geological museum (Kazan Federal University): magnetic properties and elemental composition

    Science.gov (United States)

    Kuzina, D.; Nourgaliev, D. K.; Gareev, B. I.; Batalin, G. A.; Silantiev, V. V.

    2016-12-01

    Investigations of different types meteorites were performed by non-destructive method using polycapillary Micro X-ray Fluorescence spectrometer M4 Tornado (Bruker). Analysis conditions were chosen individually, depending on a sample. Maximum possible current is 600mkA, voltage - up to 50 kV, minimum size of X-ray point from 25 micron. Result of the measurements is elements distribution on the surface of meteorites. Obtained data used for analyzing conclusions in chondrites, find out iron, nickel distribution in the sample (for comparison with thermomagnetic data), studying secondary alterations such as melting, diffusion. Meteorites which have small amount of material after preparing exhibition samples were studied using thermomagnetic analysis among them: Brownfield-iron (IID), Ochansk - ordinary chondrite (H4), Murchison - carbonaceous chondrite (CM2), Kainsaz - carbonaceous chondrite (CO3.2) and others. Thermomagnetic analysis shows us magneto-mineralogical composition. It makes reliably detection of pure Fe, Ni or their alloys. Measurements were carried out on express Curie balance, constructed in Laboratory of magnetism and paleomagnetism of Kazan Federal University [1]. We measured induced magnetization as a function of temperature in a constant magnetic field - 400 mT. The heating rate is 100°C/min. Thermomagnetic curves measured twice - first and second heating up to 800°C. The weight of the sample is maximum 0.1 gram. Results shows that all samples contain Fe-Ni alloys and according [2] it corresponds to Ni concentration between 4-10%. [1] Burov B.V. et al. 1986. Kazan: Publishing house of KSU, 167 p. (In Russian). [2] Cacciamani C. et al. 2006. Intermetallics, 14. 1312-1325

  8. CM: Becoming a technology firm (teaching case)

    NARCIS (Netherlands)

    van Burg, J.C.; Reymen, I.M.M.J.; Dolmans, S.A.M.

    2011-01-01

    Founded in 2000 as a Short Message Service (SMS) marketing company for discos (clubs), CM evolved into a technology provider for SMS services. By 2008, CM was market leader in The Netherlands, a position won by offering high quality services at low prices. In 2010, the founders of the company were

  9. Valec fireball and predicted meteorite fall

    International Nuclear Information System (INIS)

    Ceplecha, Z.; Spurny, P.

    1987-01-01

    A fireball was photographed with a luminous trajectory below a height of 20 km. On Aug. 3, 1984, seven stations photographed this slow moving fireball, which traversed 94 km of luminous trajectory in 9.2 sec and terminated its visible flight at a height of 19.1 km. The computed dark flight trajectory intersected the surface close to Valec, a small village 40 km west of Brno. The Valec fireball was the lowest photographed fireball ever. The Valec fireball was photographed by fish eye cameras. The positional precision of all the records were within the range of 1 to 2 minutes of arc. All computations were done using the FIRBAL program, a set of almost 4000 Fortran statements run on EC 1040 computer. The average computed mass at the terminal point, i.e., the predicted mass of the biggest meteorite, was 16 kg. This number is based on the dynamical data at the terminal point solely. Visual data was also collected from occasional observers. This observed phenomenon is discussed

  10. Calcium isotopic anomalies in the Allende meteorite

    International Nuclear Information System (INIS)

    Lee, T.; Papanastassiou, D.A.; Wasserburg, G.J.

    1978-01-01

    We report isotopic anomalies in Ca which were found in two Ca-Al-rich inclusions of the Allende meteorite. These inclusions previously had been shown to contain special anomalies for Mg and O which were attributed to fractionation and unknown nuclear effects. The Ca data, when corrected for mass fractionation by using 40 Ca/ 44 Ca as a standard, show nonlinear isotopic effects in 48 Ca of +13.5 per mil and in 42 Ca of +1.7 per mil for one sample. The second sample shows a 48 Ca depletion of -2.9 per mil, but all other isotopes are normal. Samples with large excesses in 26 Mg show no Ca anomalies. The effects demonstrate that isotopic anomalies exist for higher-atomic-number refractory elements in solar-system materials and do not appear to be readily explainable by a simple model. The correlation of O, Mg, and Ca results on the same inclusions requires the addition and preservation in the solar system of components from idverse nucleosynthetic sources. Observed anomalous Mg and Ca compositions for coexisting mineral phases are uniform within each inclusion, and require initial isotopic homogeneity within an inclusion but the preservation of wide variations between inclusions. Assuming formation of these inclusions by condensation from a gaseous part of the solar nebula, this implies isotopic heterogeneity on a scale of 10-10 2 km within the nebula

  11. Age of meteorites, the Moon, the Earth

    International Nuclear Information System (INIS)

    Ovchinnikova, G.V.; Levskij, L.K.

    1987-01-01

    Review of modern data on age determination of meteorites and lunar rocks and review of papers dedicted to calculations of the Earth age as well are given. Analysis of the age present values, obtained by different methods of isotopic dating has allowed to build up the global events following succession: ∼ 4.8x10 9 years ago - the beginning of dust component condensation within protosolar cloud; ∼ 4.55x10 9 year - the end of cosmic bodies accretion; (4.5-4.4)x10 9 years - differentiation of large planetray bodies (the Moon, the Mars, the Earth) with isolation of the bed type protocrust. Substance differentiation is not typical for solar system small bodies (asteroid-size bodies). Development of the magnetism of main composition (achondrites) on the surface of these bodies is their peculiarity. Both differentiation and basalt volcanism at early periods of cosmic bodies existance are initiated by exogenous factors. Duration of endogenous basalt volcanism correlates with planetary body size

  12. Physical properties of Martian meteorites: Porosity and density measurements

    Science.gov (United States)

    Coulson, Ian M.; Beech, Martin; Nie, Wenshuang

    Martian meteorites are fragments of the Martian crust. These samples represent igneous rocks, much like basalt. As such, many laboratory techniques designed for the study of Earth materials have been applied to these meteorites. Despite numerous studies of Martian meteorites, little data exists on their basic structural characteristics, such as porosity or density, information that is important in interpreting their origin, shock modification, and cosmic ray exposure history. Analysis of these meteorites provides both insight into the various lithologies present as well as the impact history of the planet's surface. We present new data relating to the physical characteristics of twelve Martian meteorites. Porosity was determined via a combination of scanning electron microscope (SEM) imagery/image analysis and helium pycnometry, coupled with a modified Archimedean method for bulk density measurements. Our results show a range in porosity and density values and that porosity tends to increase toward the edge of the sample. Preliminary interpretation of the data demonstrates good agreement between porosity measured at 100× and 300× magnification for the shergottite group, while others exhibit more variability. In comparison with the limited existing data for Martian meteorites we find fairly good agreement, although our porosity values typically lie at the low end of published values. Surprisingly, despite the increased data set, there is little by way of correlation between either porosity or density with parameters such as shock effect or terrestrial residency. Further data collection on additional meteorite samples is required before more definitive statements can be made concerning the validity of these observations.

  13. Amino Acids in the Asteroidal Water-Bearing Salt Crystals Hosted in the Zag Meteorite

    Science.gov (United States)

    Chan, Q. H. S.; Zolensky, M. E.; Burton, A. S.; Locke, D. R.

    2016-01-01

    Solid evidence of liquid water in primitive meteorites is given by the ordinary chondrites H5 Monahans (1998) and H3-6 Zag. Aqueous fluid inclusion-bearing halite (NaCl) crystals were shown to be common in Zag. These striking blue/purple crystals (Figure 1), which gained the coloration from electron-trapping in the Cl-vacancies through exposure to ionizing radiation, were determined to be over 4.0-4.7 billion years old by I-Xe dating. The halite grains are present as discrete grains within an H-chondrite matrix with no evidence for aqueous alteration that indicates a xenogenic source, possibly ancient cryovolcanism. They were proposed to be formed from the cryovolcanic plumes on icy C-type asteroids (possibly Ceres), and were transferred and incorporated into the H chondrite parent asteroid following the eruption event(s). A unique aspect of these halites is that they contain abundant solid inclusions hosted within the halites alongside the water inclusions. The solid inclusions were suggested to be entrained within the fluid erupted from the cryovolcanic event(s), and were shown to be comprised of abundant organics. Spectrofluorometric study and Raman imaging of the halites have identified macromolecular carbon and aliphatic carbon compounds. In order to investigate the type of organics present in Zag and in particular within the fluid-bearing halites, we studied for the first time the amino acid contents of a selected mineral (halite) phase in a meteorite sample.

  14. Organic material in meteorites and the link to the origin of life

    Directory of Open Access Journals (Sweden)

    Remusat L.

    2014-02-01

    Full Text Available Life requires specific conditions that have been, so far, only proven to meet on Earth. Though the chemical elements required to form living organism (C, H, N, O, S, etc are widespread in the universe, the molecules that are crucial for Life, like nucleobases or amino acids, may not be so ubiquitous. The question of the formation of small and complex molecules is highly relevant to understand the process of Life origin. Carbonaceous chondrites are a class of meteorites rich in organic compounds and host potential precursors for the emergence of Life (organic matter and water. They could have been the source of complex molecules on the early Earth. This contribution will describe the main properties of the organic matter recovered from carbonaceous chondrites. However, the isotopic and molecular record of organic compounds is faded by secondary processes that occurred on the parent body of these meteorites. This results in complex signatures that raise multiple questions about the origin of organic compounds in the Solar System.

  15. Iron Isotopic Compositions of Troilite (FeS) Inclusions from Iron Meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Cook, David L.; Schönbächler, Maria, E-mail: david.cook@erdw.ethz.ch [Institut für Geochemie und Petrologie, ETH Zürich, Clausiusstrasse 25, 8092 Zürich (Switzerland)

    2017-10-01

    We report non-mass-dependent Fe isotopic data for troilite (FeS) inclusions from 10 iron meteorites, representing both non-magmatic (IAB) and magmatic groups (IIAB, IIIAB, IVA). No resolvable variations are present in the most neutron-rich isotope ({sup 58}Fe), but small deficits (≈−0.1 ε ) in {sup 56}Fe were observed in several inclusions. With the exception of several Ca–Al-rich inclusions in primitive meteorites, these are the first reported non-mass-dependent variations in Fe isotopes for material formed in the early solar system. Nucleosynthetic variations in Ni isotopes were previously reported in these same samples. The effects in Fe isotopes are not correlated with those in Ni, which suggests that the origins of the isotopic variations are decoupled from one another. The {sup 56}Fe deficits may represent incomplete mixing of the precursor dust in the protoplanetary disk. Alternatively, a parent body process (e.g., irradiation by galactic cosmic rays) may have modified the Fe isotopic compositions of some inclusions, which initially had homogeneous Fe isotopic compositions.

  16. Neutron spectra of /sup 242/Cm-Be and /sup 244/Cm-Be neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A; Nagarajan, P S [Bhabha Atomic Research Centre, Bombay (India). Div. of Radiation Protection

    1977-02-15

    Neutron spectra of /sup 242/Cm-Be(..cap alpha..,n) and /sup 244/Cm-Be(..cap alpha..,n) sources have been calculated including the spontaneous fission contribution which is negligible for /sup 242/Cm and amounts to about 4% for /sup 244/Cm. The agreement of the present work with experimental results is poor.

  17. Comets, Asteroids, Meteorites, and the Origin of the Biosphere

    Science.gov (United States)

    Hoover, Richard B.

    2006-01-01

    photoautotrophs and chemolithotrophs such as the motile filamentous cyanobacteria (e.g., Calothrix, Oscillatoria, Phormidium, and Spirulina) that grow in geothermal springs and geysers of Earth at temperatures ranging fiom 320K to 345K and are also found growing in cold polar desert soils. The mineralized remains of morphotypes of all of these cyanobacteria have also been found in the Orgueil CI1 and the Murchison CN2 carbonaceous meteorites that may derive from cometary parent bodies. Observational results that support the hypothesis that liquid water can in active regions just beneath the surface of comets and that comets, carbonaceous meteorites, and asteroids may have played a significant role in the origin and evolution of the Biosphere and in the distribution of microbial life throughout the Solar System.

  18. Reconciliation of the excess 176Hf conundrum in meteorites: Recent disturbances of the Lu-Hf and Sm-Nd isotope systematics

    Science.gov (United States)

    Bast, Rebecca; Scherer, Erik E.; Sprung, Peter; Mezger, Klaus; Fischer-Gödde, Mario; Taetz, Stephan; Böhnke, Mischa; Schmid-Beurmann, Hinrich; Münker, Carsten; Kleine, Thorsten; Srinivasan, Gopalan

    2017-09-01

    The long-lived 176Lu-176Hf and 147Sm-143Nd radioisotope systems are commonly used chronometers, but when applied to meteorites, they can reveal disturbances. Specifically, Lu-Hf isochrons commonly yield dates up to ∼300 Myr older than the solar system and varying initial 176Hf/177Hf values. We investigated this problem by attempting to construct mineral and whole rock isochrons for eucrites and angrites. Meteorites from different parent bodies exhibit similar disturbance features suggesting that a common process is responsible. Minerals scatter away from isochron regressions for both meteorite classes, with low-Hf phases such as plagioclase and olivine typically being most displaced above (or left of) reference isochrons. Relatively Hf-rich pyroxene is less disturbed but still to the point of steepening Lu-Hf errorchrons. Using our Lu-Hf and Sm-Nd data, we tested various Hf and Lu redistribution scenarios and found that decoupling of Lu/Hf from 176Hf/177Hf must postdate the accumulation of significant radiogenic 176Hf. Therefore early irradiation or diffusion cannot explain the excess 176Hf. Instead, disturbed meteorite isochrons are more likely caused by terrestrial weathering, contamination, or common laboratory procedures. The partial dissolution of phosphate minerals may predominantly remove rare earth elements including Lu, leaving relatively immobile and radiogenic Hf behind. Robust Lu-Hf (and improved Sm-Nd) meteorite geochronology will require the development of chemical or physical methods for removing unsupported radiogenic Hf and silicate-hosted terrestrial contaminants without disturbing parent-daughter ratios.

  19. 'CM 88' - A multiple disease resistant chickpea mutant variety

    International Nuclear Information System (INIS)

    Haq, M.A.; Hassan, Mahmudul; Sadiq, M.

    2001-01-01

    Full text: Chickpea is the most important grain legume crop of Pakistan. Ascochyta blight (Ascochyta rabiei) and Fusarium wilt (Fusarium oxysporum F. sp cicer) are most serious diseases, having the potential to devastate a crop. A multiple disease resistant and high yielding mutant CM 88 has been developed through 100 Gy gamma irradiation treatment of variety 'C 727'. This was once a widely grown and popular variety, which lost its resistance to Ascochyta and was replaced. The selection of mutants was performed in the M2 generation grown in the Ascochyta blight nursery and sixteen mutants were selected. In the subsequent generations CM 88 proved resistant to both Ascochyta blight and Fusarium wilt, and exhibited superiority in agronomic characteristics. CM 88 was also tested for many years in the various yield trials on research stations and farmers fields throughout the country. In these trials it out yielded both the parent and standard varieties. The mutant CM 88 has been approved by the Punjab Seed Council on 27 October 1994 for general cultivation in the Punjab Province, especially the Thal area which accounts for more than 70% of the area under chickpea cultivation. (author)

  20. Mineralogical composition of the meteorite El Pozo (Mexico): a Raman, infrared and XRD study.

    Science.gov (United States)

    Ostrooumov, Mikhail; Hernández-Bernal, Maria del Sol

    2011-12-01

    The Raman (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of El Pozo meteorite (an ordinary chondrite L5 type; village Valle of Allende, founded in State of Chihuahua, Mexico: 26°56'N and 105°24'W, 1998). RMP measurements in the range of 100-3500 cm(-1) revealed principal characteristic bands of the major minerals: olivine, two polymorph modifications of pyroxene (OPx and CPx) and plagioclase. Some bands of the minor minerals (hematite and goethite) were also identified. All these minerals were clearly distinguished using IR and XRD techniques. XRD technique has shown the presence of some metallic phases such as kamacite and taenite as well as troilite and chromite. These minerals do not have characteristic Raman spectra because Fe-Ni metals have no active modes for Raman spectroscopy and troilite is a weak Raman scatterer. Raman mapping microspectroscopy was a key part in the investigation of El Pozo meteorite's spatial distribution of the main minerals because these samples are structurally and chemically complex and heterogeneous. The mineral mapping by Raman spectroscopy has provided information for a certain spatial region on which a spatial distribution coexists of the three typical mineral assemblages: olivine; olivine+orthopyroxene; and orthopyroxene. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. The Meteorite Fall in Carancas, Lake Titicaca Region, Southern Peru: First Results

    Science.gov (United States)

    Núñez Del Prado, H.; Macharé, J.; Macedo, L.; Chirif, H.; Pari, W.; Ramirez-Cardona, M.; Aranda, A.; Greenwood, R. C.; Franchi, I. A.; Canepa, C.; Bernhardt, H.-J.; Plascencia, L.

    2008-03-01

    The meteorite fall that occurred on September 15, 2007, in the Carancas community is a rare case where it is possible to study both impact phenomenology and meteorite characteristics, including accurate time framework.

  2. Expected Geochemical and Mineralogical Properties of Meteorites from Mercury: Inferences from Messenger Data

    Science.gov (United States)

    McCubbin, F. M.; McCoy, T. J.

    2016-01-01

    Meteorites from the Moon, Mars, and many types of asteroid bodies have been identified among our global inventory of meteorites, however samples of Mercury and Venus have not been identified. The absence of mercurian and venusian meteorites could be attributed to an inability to recognize them in our collections due to a paucity of geochemical information for Venus and Mercury. In the case of mercurian meteorites, this possibility is further supported by dynamical calculations that suggest mercurian meteorites should be present on Earth at a factor of 2-3 less than meteorites from Mars [1]. In the present study, we focus on the putative mineralogy of mercurian meteorites using data obtained from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, which has provided us with our first quantitative constraints on the geochemistry of planet Mercury. We have used the MESSENGER data to compile a list of mineralogical and geochemical characteristics that a meteorite from Mercury is likely to exhibit.

  3. Annama H5 meteorite fall: orbit, trajectory, recovery, petrology, noble gases and cosmogenic radionuclides

    Czech Academy of Sciences Publication Activity Database

    Kohout, Tomáš; Gritsevich, M.; Lyytinen, E.; Moilanen, J.

    2015-01-01

    Roč. 50, Supplement 1 SI (2015) [Annual Meeting of the Meteoritical Society /78./. 27.07.2015-31.07.2015, Berkeley] Institutional support: RVO:67985831 Keywords : meteorite * astrophysics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  4. Volatile elements in Allende inclusions. [Mn, Na and Cl relation to meteorite evolution

    Science.gov (United States)

    Grossman, L.; Ganapathy, R.

    1975-01-01

    New data are presented on the relatively volatile elements (Mn, Na, and Cl) in coarse- and fine-grained Ca/Al-rich inclusions of different textures and mineralogy in the Allende meteorite. It is shown that the coarse-grained inclusions condensed from the solar nebula at high temperature and contained vanishingly small quantities of volatile elements at that time. Later, volatiles were added to these during the metamorphism of the Allende parent body. The fine-grained inclusions were also affected by the addition of volatiles during this metamorphism but, unlike the coarse-grained ones, they incorporated large amounts of volatiles when they condensed from the solar nebula, accounting for their higher volatile element contents.

  5. An assessment of the meteoritic contribution to the Martian soil

    International Nuclear Information System (INIS)

    Flynn, G.J.; McKay, D.S.

    1990-01-01

    The addition of meteoritic material to the Mars soils should perturb their chemical compositions, as has been detected for soils on the Moon and sediments on Earth. Using the measured mass influx at Earth and estimates of the Mars/Earth flux ratio, the authors estimate the continuous, planet-wide meteoritic mass influx on Mars to be between 2,700 and 59,000 t/yr. If distributed uniformly into a soil with a mean planetary production rate of 1 m/b.y., consistent with radar estimates of the soil depth overlaying a bouldered terrain in the Tharsis region, their estimated mass influx would produce a meteoritic concentration in the Mars soil ranging from 2 to 29% by mass. Analysis of the Viking X ray fluorescence data indicates that the Mars soil composition is inconsistent with typical basaltic rock fragments but can be fit by a mixture of 60% basaltic rock fragments and 40% meteoritic material. The meteoritic influx they calculate is sufficient to provide most or all of the material required by the Clark and Baird model. Particles in the mass range from 10 -7 to 10 -3 g, about 60-1,200 μm in diameter, contribute 80% of the total mass flux of meteoritic material in the 10 -13 to 10 6 g mass range at Earth. On Earth atmospheric entry all but the smallest particles (generally ≤ 50 μm in diameter) in the 10 -7 to 10 -3 g mass range are heated sufficiently to melt or vaporize. Mars, because of its lower escape velocity and larger atmospheric scale height, is a much more favorable site for unmelted survival of micrometeorites on atmospheric deceleration. They calculate that a significant fraction of particles throughout the 60-1,200 μm diameter range will survive Mars atmospheric entry unmelted

  6. Abundances of presolar silicon carbide grains in primitive meteorites determined by NanoSIMS

    Science.gov (United States)

    Davidson, Jemma; Busemann, Henner; Nittler, Larry R.; Alexander, Conel M. O.'D.; Orthous-Daunay, François-Régis; Franchi, Ian A.; Hoppe, Peter

    2014-08-01

    It has been suggested that the matrices of all chondrites are dominated by a common material with Ivuna-like (CI) abundances of volatiles, presolar grains and insoluble organic matter (IOM) (e.g., Alexander, 2005). However, matrix-normalized abundances of presolar silicon carbide (SiC) grains estimated from their noble gas components show significant variations in even the most primitive chondrites (Huss and Lewis, 1995; Huss et al., 2003), in contradiction to there being a common chondrite matrix material. Here we report presolar SiC abundances determined by NanoSIMS raster ion imaging of IOM extracted from primitive members of different meteorite groups. We show that presolar SiC abundance determinations are comparable between NanoSIMS instruments located at three different institutes, between residues prepared by different demineralization techniques, and between microtomed and non-microtomed samples. Our derived SiC abundances in CR chondrites are comparable to those found in the CI chondrites (∼30 ppm) and are much higher than previously determined by noble gas analyses. The revised higher CR SiC abundances are consistent with the CRs being amongst the most primitive chondrites in terms of the isotopic compositions and disordered nature of their organic matter. Similar abundances between CR1, CR2, and CR3 chondrites indicate aqueous alteration on the CR chondrite parent body has not progressively destroyed SiC grains in them. A low SiC abundance for the reduced CV3 RBT 04133 can be explained by parent body thermal metamorphism at an estimated temperature of ∼440 °C. Minor differences between primitive members of other meteorite classes, which did not experience such high temperatures, may be explained by prolonged oxidation at lower temperatures under which SiC grains formed outer layers of SiO2 that were not thermodynamically stable, leading to progressive degassing/destruction of SiC.

  7. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.

    Science.gov (United States)

    2010-10-01

    ... Antarctica. 674.4 Section 674.4 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research purposes. ...

  8. Determination of refractory trace elements in Chinese meteorites by RNAA

    International Nuclear Information System (INIS)

    Kraehenbuehl, U.; Burger, M.

    1989-01-01

    Some refractory trace elements are important target elements for spallation reactions in meteorites. These elements also serve to characterize the investigated meteorites. The elements Ti, Y, Zr, Hf, W and Ta were measured after radiochemical separation in chondrites from China. After acid digestion of the irradiated samples, the group separations were obtained by precipitation reactions. The necessary radiochemical purification of the pure β emitter Y was realized on a Lewatite OC 1026 column. For all the other elements discrete gamma radiation was measured. (orig.)

  9. The Organic Content of the Tagish Lake Meteorite

    Science.gov (United States)

    Pizzarello, Sandra; Huang, Yongsong; Becker, Luann; Poreda, Robert J.; Nieman, Ronald A.; Cooper, George; Williams, Michael

    2001-01-01

    The Tagish Lake meteorite felt last year on a frozen take in Canada and may provide the most pristine material of its kind. Analyses have now shown this carbonaceous chondrite to contain a suite of soluble organic compounds (approximately 100 parts per million) that includes mono- and dicarboxylic acids, dicarboximides, pyridine carboxylic acids, a sulfonic acid, and both aliphatic and aromatic hydrocarbons. The insoluble carbon exhibits exclusive aromatic character, deuterium enrichment, and fullerenes containing 'planetary' helium and argon. The findings provide insight into an outcome of early solar chemical evolution that differs from any seen so far in meteorites.

  10. Preferential occupation of pyroxene sites by iron in diogenite meteorites

    International Nuclear Information System (INIS)

    Verma, H. C.; Tewari, V. C.; Paliwal, B. S.; Tripathi, R. P.

    2008-01-01

    Three diogenite meteorites ALHA77256-121, Tatahounie and Bilanga are studied using Moessbauer spectroscopy to look at the iron occupancy in the two inequivalent pyroxene sites. Though the three meteorites belong to three different conditions, one is an Antarctica find, one is 75 years old fall and one is a recent fall, the iron occupancy in pyroxene sites is very similar. Fe 2+ occupies only the less distorted site and hence a single sharp doublet is observed in the Moessbauer spectra of all these samples. In contrast eucrites show a distribution of iron ions in the two sites of pyroxenes.

  11. Robust Foregrounds Removal for 21-cm Experiments

    Science.gov (United States)

    Mertens, F.; Ghosh, A.; Koopmans, L. V. E.

    2018-05-01

    Direct detection of the Epoch of Reionization via the redshifted 21-cm line will have unprecedented implications on the study of structure formation in the early Universe. To fulfill this promise current and future 21-cm experiments will need to detect the weak 21-cm signal over foregrounds several order of magnitude greater. This requires accurate modeling of the galactic and extragalactic emission and of its contaminants due to instrument chromaticity, ionosphere and imperfect calibration. To solve for this complex modeling, we propose a new method based on Gaussian Process Regression (GPR) which is able to cleanly separate the cosmological signal from most of the foregrounds contaminants. We also propose a new imaging method based on a maximum likelihood framework which solves for the interferometric equation directly on the sphere. Using this method, chromatic effects causing the so-called ``wedge'' are effectively eliminated (i.e. deconvolved) in the cylindrical (k⊥, k∥) power spectrum.

  12. Halogens in chondritic meteorites and terrestrial accretion

    Science.gov (United States)

    Clay, Patricia L.; Burgess, Ray; Busemann, Henner; Ruzié-Hamilton, Lorraine; Joachim, Bastian; Day, James M. D.; Ballentine, Christopher J.

    2017-11-01

    Volatile element delivery and retention played a fundamental part in Earth’s formation and subsequent chemical differentiation. The heavy halogens—chlorine (Cl), bromine (Br) and iodine (I)—are key tracers of accretionary processes owing to their high volatility and incompatibility, but have low abundances in most geological and planetary materials. However, noble gas proxy isotopes produced during neutron irradiation provide a high-sensitivity tool for the determination of heavy halogen abundances. Using such isotopes, here we show that Cl, Br and I abundances in carbonaceous, enstatite, Rumuruti and primitive ordinary chondrites are about 6 times, 9 times and 15-37 times lower, respectively, than previously reported and usually accepted estimates. This is independent of the oxidation state or petrological type of the chondrites. The ratios Br/Cl and I/Cl in all studied chondrites show a limited range, indistinguishable from bulk silicate Earth estimates. Our results demonstrate that the halogen depletion of bulk silicate Earth relative to primitive meteorites is consistent with the depletion of lithophile elements of similar volatility. These results for carbonaceous chondrites reveal that late accretion, constrained to a maximum of 0.5 ± 0.2 per cent of Earth’s silicate mass, cannot solely account for present-day terrestrial halogen inventories. It is estimated that 80-90 per cent of heavy halogens are concentrated in Earth’s surface reservoirs and have not undergone the extreme early loss observed in atmosphere-forming elements. Therefore, in addition to late-stage terrestrial accretion of halogens and mantle degassing, which has removed less than half of Earth’s dissolved mantle gases, the efficient extraction of halogen-rich fluids from the solid Earth during the earliest stages of terrestrial differentiation is also required to explain the presence of these heavy halogens at the surface. The hydropilic nature of halogens, whereby they track

  13. Magnesium isotope systematics in Martian meteorites

    Science.gov (United States)

    Magna, Tomáš; Hu, Yan; Teng, Fang-Zhen; Mezger, Klaus

    2017-09-01

    Magnesium isotope compositions are reported for a suite of Martian meteorites that span the range of petrological and geochemical types recognized to date for Mars, including crustal breccia Northwest Africa (NWA) 7034. The δ26Mg values (per mil units relative to DSM-3 reference material) range from -0.32 to -0.11‰; basaltic shergottites and nakhlites lie to the heavier end of the Mg isotope range whereas olivine-phyric, olivine-orthopyroxene-phyric and lherzolitic shergottites, and chassignites have slightly lighter Mg isotope compositions, attesting to modest correlation of Mg isotopes and petrology of the samples. Slightly heavier Mg isotope compositions found for surface-related materials (NWA 7034, black glass fraction of the Tissint shergottite fall; δ26Mg > -0.17‰) indicate measurable Mg isotope difference between the Martian mantle and crust but the true extent of Mg isotope fractionation for Martian surface materials remains unconstrained. The range of δ26Mg values from -0.19 to -0.11‰ in nakhlites is most likely due to accumulation of clinopyroxene during petrogenesis rather than garnet fractionation in the source or assimilation of surface material modified at low temperatures. The rather restricted range in Mg isotope compositions between spatially and temporally distinct mantle-derived samples supports the idea of inefficient/absent major tectonic cycles on Mars, which would include plate tectonics and large-scale recycling of isotopically fractionated surface materials back into the Martian mantle. The cumulative δ26Mg value of Martian samples, which are not influenced by late-stage alteration processes and/or crust-mantle interactions, is - 0.271 ± 0.040 ‰ (2SD) and is considered to reflect δ26Mg value of the Bulk Silicate Mars. This value is robust taking into account the range of lithologies involved in this estimate. It also attests to the lack of the Mg isotope variability reported for the inner Solar System bodies at current

  14. Estimation of radioactive contaminants in Cm242 and Cm244 isotopic fuels

    International Nuclear Information System (INIS)

    Terent'ev, V.P.; Makarenko, A.I.

    1972-01-01

    The radiation properties of Cm 242 and Cm 244 preparations and the effect on them of possible contaminants are considered. One of the most important requirements for K alpha active fuels for radioisotope thermoelectric batteries is ensuring a low ionizing radiation background. In determining the effect of impurities on the radiation properties of a preparation, quantitative evaluation of certain factors is sufficient. In a Cm 242 preparation it is possible to show that Am 241 and Cm 243 are undesirable impurities. The presence of Am 241 increases the soft gamma output by 20%. The presence of Cm 243 may double the dose rate from an unshielded preparation and increase the hard gamma output 10-fold. The properties of Cm 242 preparations deteriorate when Am 243 and Cm 243 are present

  15. CM Net heterogeneous local network of microcomputers

    International Nuclear Information System (INIS)

    Gutche, R.Kh.

    1988-01-01

    Realization of the CM Net heterogeneous local network for the PDP-11 type computers with the RT-11 operational system control is described. The main advantage of the network is the realization of virtual disks in general form including a system unit. the network can be used everywhere, where the problem on computer connection by simple interfaces is stated. 6 refs

  16. Neutron resonance parameters of CM isotopes

    International Nuclear Information System (INIS)

    Belanova, T.S.; Kolesov, A.G.; Poruchikov, V.A.

    1977-01-01

    The total neutron cross sections of isotopes 244, 245, 246, 248 Curium have been measured on reactor CM-2 using the time-of-flight method. Single-level Breit-Wigner resonance parameters: energy E 0 , neutron width 2g GITAn, total width GITA, total neutron cross section in resonance sigma 0 have been obtained by the shape and area methods

  17. THE CULTURAL HISTORY OF THE INNAANGANEQ/ CAPE YORK METEORITE

    DEFF Research Database (Denmark)

    Appelt, Martin; Jensen, Jens Fog; Myrup, Mikkel

    2015-01-01

    can be used to detect buried even deeply buried iron meteorites, and that the background noise is significantly less than the expected. The additional scannings done in 2014 indicate that the anomalies are more likely to be the result of terrestial rather than extraterrestial phenomenons....

  18. The Kosice meteorite fall: Recovery and strewn field

    Czech Academy of Sciences Publication Activity Database

    Toth, J.; Svoreň, J.; Borovička, Jiří; Spurný, Pavel; Igaz, A.; Kornos, L.; Vereš, P.; Husárik, M.; Koza, J.; Kučera, A.; Zigo, P.; Gajdoš, Š.; Világi, J.; Čapek, David; Krisandova, Z.; Tomko, D.; Šilha, J.; Schunová, E.; Bodnárová, M.; Búzová, Diana; Krejčová, T.

    2015-01-01

    Roč. 50, č. 5 (2015), s. 853-863 ISSN 1086-9379 R&D Projects: GA ČR(CZ) GAP209/11/1382 Institutional support: RVO:67985815 ; RVO:67179843 Keywords : Kosice meteorite * fragments * impact Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; EI - Biotechnology ; Bionics (UEK-B) Impact factor: 2.819, year: 2015

  19. Magnetic, in situ, mineral characterization of Chelyabinsk meteorite thin section

    Science.gov (United States)

    Nabelek, Ladislav; Mazanec, Martin; Kdyr, Simon; Kletetschka, Gunther

    2015-06-01

    Magnetic images of Chelyabinsk meteorite's (fragment F1 removed from Chebarkul lake) thin section have been unraveled by a magnetic scanning system from Youngwood Science and Engineering (YSE) capable of resolving magnetic anomalies down to 10-3 mT range from about 0.3 mm distance between the probe and meteorite surface (resolution about 0.15 mm). Anomalies were produced repeatedly, each time after application of magnetic field pulse of varying amplitude and constant, normal or reversed, direction. This process resulted in both magnetizing and demagnetizing of the meteorite thin section, while keeping the magnetization vector in the plane of the thin section. Analysis of the magnetic data allows determination of coercivity of remanence (Bcr) for the magnetic sources in situ. Value of Bcr is critical for calculating magnetic forces applicable during missions to asteroids where gravity is compromised. Bcr was estimated by two methods. First method measured varying dipole magnetic field strength produced by each anomaly in the direction of magnetic pulses. Second method measured deflections of the dipole direction from the direction of magnetic pulses. Bcr of magnetic sources in Chelyabinsk meteorite ranges between 4 and 7 mT. These magnetic sources enter their saturation states when applying 40 mT external magnetic field pulse.

  20. The Prevailing Catalytic Role of Meteorites in Formamide Prebiotic Processes.

    Science.gov (United States)

    Saladino, Raffaele; Botta, Lorenzo; Di Mauro, Ernesto

    2018-02-22

    Meteorites are consensually considered to be involved in the origin of life on this Planet for several functions and at different levels: (i) as providers of impact energy during their passage through the atmosphere; (ii) as agents of geodynamics, intended both as starters of the Earth's tectonics and as activators of local hydrothermal systems upon their fall; (iii) as sources of organic materials, at varying levels of limited complexity; and (iv) as catalysts. The consensus about the relevance of these functions differs. We focus on the catalytic activities of the various types of meteorites in reactions relevant for prebiotic chemistry. Formamide was selected as the chemical precursor and various sources of energy were analyzed. The results show that all the meteorites and all the different energy sources tested actively afford complex mixtures of biologically-relevant compounds, indicating the robustness of the formamide-based prebiotic chemistry involved. Although in some cases the yields of products are quite small, the diversity of the detected compounds of biochemical significance underlines the prebiotic importance of meteorite-catalyzed condensation of formamide.

  1. The Prevailing Catalytic Role of Meteorites in Formamide Prebiotic Processes

    Directory of Open Access Journals (Sweden)

    Raffaele Saladino

    2018-02-01

    Full Text Available Meteorites are consensually considered to be involved in the origin of life on this Planet for several functions and at different levels: (i as providers of impact energy during their passage through the atmosphere; (ii as agents of geodynamics, intended both as starters of the Earth’s tectonics and as activators of local hydrothermal systems upon their fall; (iii as sources of organic materials, at varying levels of limited complexity; and (iv as catalysts. The consensus about the relevance of these functions differs. We focus on the catalytic activities of the various types of meteorites in reactions relevant for prebiotic chemistry. Formamide was selected as the chemical precursor and various sources of energy were analyzed. The results show that all the meteorites and all the different energy sources tested actively afford complex mixtures of biologically-relevant compounds, indicating the robustness of the formamide-based prebiotic chemistry involved. Although in some cases the yields of products are quite small, the diversity of the detected compounds of biochemical significance underlines the prebiotic importance of meteorite-catalyzed condensation of formamide.

  2. JESENICE (L6)-A RECENT METEORITE FALL FROM SLOVENIA

    Czech Academy of Sciences Publication Activity Database

    Bischoff, A.; Jersek, M.; Grau, T.; Mirtic, B.; Ott, U.; Kučera, Jan; Horstmann, M.; Laubenstein, M.; Herrmann, S.; Řanda, Zdeněk; Weber, M.; Heusser, G.

    2010-01-01

    Roč. 45, Suppl. S (2010), A15-A15 ISSN 1086-9379. [73rd Annual Meeting of the Meteoritical-Society. 26.07.2010-30.07.2010, New York] Institutional research plan: CEZ:AV0Z10480505 Keywords : SHOCK METAMORPHISM Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  3. Geochemistry of Lunar Highland Meteorites Mil, 090034, 090036 AND 090070

    Science.gov (United States)

    Shirai, N.aoki; Ebihara, M.; Sekimoto, S.; Yamaguchi, A.; Nyquist, L.; Shih, C.-Y.; Park, J.; Nagao, K.

    2012-01-01

    Apollo and Luna samples were collected from a restricted area on the near side of the Moon, while the source craters of the lunar meteorites are randomly distributed. For example, Takeda et al. [1] and Yamaguchi et al. [2] found a variety of lithic clasts in Dho 489 and Y 86032 which were not represented by Apollo samples, and some of these clasts have lower rare earth elements (REE) and FeO abundances than Apollo anorthosites, respectively. Takeda et al. [1] and Yamaguchi et al. [2] concluded that Dho 489 and Y 86032 originated from the lunar farside. Therefore, lunar meteorites provide an opportunity to study lunar surface rocks from areas not sampled by Apollo and Luna missions. Three lunar anorthitic breccias (MIL 090034, 090036 and 090070) were found on the Miller Range Ice Field in Antarctica during the 2009-2010 ANSMET season [3]. In this study, we determined elemental abudnances for MIL 090034, 090036 and 090070 by using INAA and aimed to characterize these meteorites in chemical compositions in comparison with those for other lunar meteorites and Apollo samples.

  4. Meteorite Fall Detection and Analysis via Weather Radar: Worldwide Potential for Citizen Science

    Science.gov (United States)

    Fries, M.; Bresky, C.; Laird, C.; Reddy, V.; Hankey, M.

    2017-12-01

    Meteorite falls can be detected using weather radars, facilitating rapid recovery of meteorites to minimize terrestrial alteration. Imagery from the US NEXRAD radar network reveals over two dozen meteorite falls where meteorites have been recovered, and about another dozen that remain unrecovered. Discovery of new meteorite falls is well suited to "citizen science" and similar outreach activities, as well as automation of computational components into internet-based search tools. Also, there are many more weather radars employed worldwide than those in the US NEXRAD system. Utilization of weather radars worldwide for meteorite recovery can not only expand citizen science opportunities but can also lead to significant improvement in the number of freshly-fallen meteorites available for research. We will discuss the methodologies behind locating and analyzing meteorite falls using weather radar, and how to make them available for citizen science efforts. An important example is the Aquarius Project, a Chicago-area consortium recently formed with the goal of recovering meteorites from Lake Michigan. This project has extensive student involvement geared toward development of actual hardware for recovering meteorites from the lake floor. Those meteorites were identified in weather radar imagery as they fell into the lake from a large meteor on 06 Feb 2017. Another example of public interaction is the meteor detection systems operated by the American Meteor Society (AMS). The AMS website has been developed to allow public reporting of meteors, effectively enabling citizen science to locate and describe significant meteor events worldwide.

  5. The dimension added by 3D scanning and 3D printing of meteorites

    Science.gov (United States)

    de Vet, S. J.

    2016-01-01

    An overview for the 3D photodocumentation of meteorites is presented, focussing on two 3D scanning methods in relation to 3D printing. The 3D photodocumention of meteorites provides new ways for the digital preservation of culturally, historically or scientifically unique meteorites. It has the potential for becoming a new documentation standard of meteorites that can exist complementary to traditional photographic documentation. Notable applications include (i.) use of physical properties in dark flight-, strewn field-, or aerodynamic modelling; (ii.) collection research of meteorites curated by different museum collections, and (iii.) public dissemination of meteorite models as a resource for educational users. The possible applications provided by the additional dimension of 3D illustrate the benefits for the meteoritics community.

  6. Searching for Extraterrestrial Amino Acids in a Contaminated Meteorite: Amino Acid Analyses of the Canakkale L6 Chondrite

    Science.gov (United States)

    Burton, A. S.; Elsila, J. E.; Glavin, D. P.; Dworkin, J. P.; Ornek, C. Y.; Esenoglu, H. H.; Unsalan, O.; Ozturk, B.

    2016-01-01

    Amino acids can serve as important markers of cosmochemistry, as their abundances and isomeric and isotopic compositions have been found to vary predictably with changes in parent body chemistry and alteration processes. Amino acids are also of astrobiological interest because they are essential for life on Earth. Analyses of a range of meteorites, including all groups of carbonaceous chondrites, along with H, R, and LL chondrites, ureilites, and a martian shergottite, have revealed that amino acids of plausible extraterrestrial origin can be formed in and persist after a wide range of parent body conditions. However, amino acid analyses of L6 chondrites to date have not provided evidence for indigenous amino acids. In the present study, we performed amino acid analysis on larger samples of a different L6 chondite, Canakkale, to determine whether or not trace levels of indigenous amino acids could be found. The Canakkale meteor was an observed fall in late July, 1964, near Canakkale, Turkey. The meteorite samples (1.36 and 1.09 g) analyzed in this study were allocated by C. Y. Ornek, along with a soil sample (1.5 g) collected near the Canakkale recovery site.

  7. The evolution of meteorites and planets from a hot nebula

    Directory of Open Access Journals (Sweden)

    Donald H. Tarling

    2015-06-01

    Full Text Available Meteorites have a hot origin as planetary materials derive from a supernova, similar to SN1987A, and were acquired by a nearby nova, the Sun. The supernova plasmas became zoned around the nova, mainly by their electromagnetic properties. Carbon and carbide dusts condensed first, followed, within the Inner Planetary Zone, by Ca–Mg–Al oxides and then by iron and nickel metal droplets. In the inner Asteroid Belt, the metals aggregated into clumps as they solidified but over a much longer time in the Inner Zone. ‘Soft’ collisions formed larger (<∼20 km objects in the Asteroid Belt; in the Inner Zone these aggregated forming proto-planetary cores during inwards orbital migration. In the Asteroid Belt, glassy olivines condensed, followed more open lattice minerals growing grew primarily by diffusion. Brittle silicate crystals were comminuted and only aggregated into the carbonaceous meteorites when water–ices formed. The inner planets differentiated by at least 4.4 Ga. Jupiter and the outer planets grew on asteroidal bodies thrown out into freezing water vapours and only formed by 4.1 Ga, resulting in the Late Heavy Bombardment, initially by meteoritic materials and later supplemented by ices from, and beyond, the Asteroid Belt. Critical factors are the properties of very high temperature supernova plasmas, the duration of the molten iron phase in the inner zone. Evidence usually quoted for a cold origin derives from late stage processes in hot meteorite evolution. While highly speculative, it is shown that meteorites and planets can be formed by known processes as supernova plasmas cool.

  8. The Tianlai 21cm intensity mapping experiment

    Science.gov (United States)

    Chen, Xuelei

    2015-08-01

    The Tianlai 21cm intensity mapping experiment is aimed at surveying the northern sky 21cm intensity at mid-redshifts, thus map out the neutral hydrogen distribution. The experiment is named "Tianlai" which means "heavenly sound" in classic Chinese, because its ultimate goal is to use the baryon acoustic oscillation (BAO) feature in the correlation function or power spectrum of large scale structure to constrain the cosmic expansion rate, and determine the nature of dark energy.The pathfinder experiment consists three cylinder reflectors of 15m wide x 40m long, and 16 dishes of 6 meter aperture, for testing the basic principle and key technologies. A radio-quiet site in Hongliuxia, Xinjiang of north-west China is selected, currently the facilities are under construction, and the prototype is expected to start commissioning later this year. The experiment is run by NAOC, with members from France, USA and Canada.

  9. Carbothermic synthesis of (Cm,Pu)N

    International Nuclear Information System (INIS)

    Takano, Masahide; Itoh, Akinori; Akabori, Mitsuo; Ogawa, Toru; Numata, Masami; Okamoto, Hisato

    2001-01-01

    Nitrides are being considered as fuel candidates for the transmutation of minor actinides. Carbothermic reduction of oxides is an effective method to fabricate nitride fuels. In this study, (Cm 0.40 ,Pu 0.60 )N was synthesized by the carbothermic reduction of the mixed oxide in N 2 . By applying excess carbon, an oxide-free nitride was obtained at 1773 K. The lattice parameter of the oxide-free sample was 0.4948 nm, and that of the nitride with oxides was 0.4974 nm. The former value agreed well with that estimated from the literature values for CmN and PuN. The larger lattice parameter of the latter sample is considered to be due to the oxygen dissolved in the nitride. (authors)

  10. Representasi Persahabatan dalam Film 5 Cm

    OpenAIRE

    Handayani, Intan Murni; Lukmantoro, Triyono; Naryoso, Agus

    2013-01-01

    Representasi Persahabatan dalam Film 5 cmSkripsiDisusun untuk memenuhi persyaratan menyelesaikanPendidikan Strata-1Jurusan IlmumKomunikasi Fakultas Ilmu Sosial dan Ilmu PolitikUniversitas DiponegoroPenyusunNama: Intan Murni HandayaniNIM: D2C 009 034JURUSAN ILMU KOMUNIKASIFAKULTAS ILMU SOSIAL DAN ILMU POLITIKUNIVERSITAS DIPONEGOROSEMARANG2013ABSTRAKSIFilm merupakan salah satu media massa yang menjadi wadah bagi parapembuat film untuk menyampaikan pesan serta nilai-nilai yang dimiliki olehpara ...

  11. 21-cm Fluctuations from Charged Dark Matter

    OpenAIRE

    Muñoz, Julian B.; Dvorkin, Cora; Loeb, Abraham

    2018-01-01

    The epoch of the formation of the first stars, known as the cosmic dawn, has emerged as a new arena in the search for dark matter. In particular, the first claimed 21-cm detection exhibits a deeper global absorption feature than expected, which could be caused by a low baryonic temperature. This has been interpreted as a sign for electromagnetic interactions between baryons and dark matter. However, in order to remain consistent with the rest of cosmological observations, only part of the dar...

  12. 57Fe Moessbauer Spectroscopy Studies of Meteorites: Implications for Weathering Rates, Meteorite Flux, and Early Solar System Processes

    International Nuclear Information System (INIS)

    Bland, P. A.; Berry, F. J.; Jull, A. J. T.; Smith, T. B.; Bevan, A. W. R.; Cadogan, J. M.; Sexton, A. S.; Franchi, L. A.; Pillinger, C. T.

    2002-01-01

    Ordinary chondrite finds, terrestrial age dated using 14 C analyses, from different meteorite accumulation sites, have been examined by Moessbauer spectroscopy to quantitatively determine terrestrial oxidation. We observe differences in weathering rates between sites, and also between different chondrite groups. A comparison of weathering over time, and its effect in 'eroding' meteorites, together with the number and mass distribution of meteorites in each region, enables us to derive estimates of the number of meteorite falls over a given mass per year. Studies of how the oxygen isotopic composition of samples varies with weathering indicate that incipient alteration may occur without a pronounced isotopic effect, possibly due to weathering of silicates to topotactically oriented smectite confined spaces where the water volume is limited. This finding has profound implications for the use of oxygen isotopes as a tool in understanding water-rock interaction. It also may reconcile previously contradictory data regarding the nebular or asteroidal location of pre-terrestrial aqueous alteration. Finally, Moessbauer spectroscopy is also found to be a useful tool in determining mineral abundance in carbonaceous chondrites, where a fine-grained matrix makes traditional approaches inapplicable. Again, the results have implications for the modification of chondritic materials in the early solar system.

  13. Physics at 1034 cm-2 s-1

    International Nuclear Information System (INIS)

    Diebold, R.; Wagner, R.

    1984-01-01

    Most of the detector studies at Snowmass-84 have rightfully concentrated on detailed studies of individual interactions - their rates, signatures, and backgrounds. Depending on the physics and the detector components, there seems to be agreement that general-purpose detectors will likely be able to accept luminosities up to 10 32-33 cm -2 s -1 . The purpose of this paper is to show how the physics reach of the SSC is extended by going to a luminosity of 10 34 cm -2 s -1 , to take a first look at what sort of detector could be used at this luminosity, and to discuss how one might trigger on interesting events in the presence of many overlapping minimum bias events. We will assume that the SSC turns on at 10 31 or 10 32 cm -2 s -1 , with an increase of luminosity to 10 33 over a period of a few years as the machine and detectors become better understood. Thus, the lower mass scale will have been explored and we can set our thresholds high when running 10 34

  14. Laboratory spectroscopy of meteorite samples at UV-vis-NIR wavelengths: Analysis and discrimination by principal components analysis

    Science.gov (United States)

    Penttilä, Antti; Martikainen, Julia; Gritsevich, Maria; Muinonen, Karri

    2018-02-01

    Meteorite samples are measured with the University of Helsinki integrating-sphere UV-vis-NIR spectrometer. The resulting spectra of 30 meteorites are compared with selected spectra from the NASA Planetary Data System meteorite spectra database. The spectral measurements are transformed with the principal component analysis, and it is shown that different meteorite types can be distinguished from the transformed data. The motivation is to improve the link between asteroid spectral observations and meteorite spectral measurements.

  15. The Acapulco Parent Planetesimal: An Early Collisional History in the Solar System

    Science.gov (United States)

    Marti, K.; Kim, Y.

    2007-05-01

    The Acapulco, Mexico, meteorite was recovered in 1976 from a crater of approx. 30 cm diameter. An old crystallization age of 4.60 (error 0.03) Ga (Prinzhofer et al., 1992) establishes that its parent object is one of the oldest known planetesimals in the solar system, although not in a pristine form. Other dating systems indicated somewhat younger ages and isotopic variabilities in several elements documented a complex early history. The younger ages date the closure times in secondary minerals. The initial parent object was in a partially molten state when isotopically distinct foreign matter invaded the chondritic parent and some of the isotopic signatures survived. Nitrogen in the primitive achondrite Acapulco was found to have distinct isotopic signatures for the metal and silicate phases and also in different morphologies of graphites (El Goresy, 1995, 2005). The delayed collisional event probably disrupted the parent object, as Acapulco cooled very rapidly. Nitrogen in the injected metal and graphite did not isotopically exchange with the host silicates. We observed nitrogen isotopic signatures of several separated mineral phases which cover a range of delta 15N values from -150 permil to +13 permil. The lightest nitrogen signatures observed in metal separates are comparable to those in some morphologies of Acapulco graphites. The heavy N signatures observed in several silicate minerals are consistent with each other, while nitrogen in chromite is distinctly light (delta 15N of -80 permil), intermediate between those of metal and silicates. The incipient rapid cooling history is well documented down to approx. 120° C, as recorded by U/Th-4He ages in phosphates (Min et al., 2003). The history of the Acapulco parent object was uneventful after its early evolution in an environment where no perturbation by collisions occurred, until the meteorite's recent (6.0 Ma ago) injection into an earth-crossing orbit. References: El Goresy, A., Zinner, E., and Marti, K

  16. Isotopic Evidence for Multi-stage Cosmic-ray Exposure Histories of Lunar Meteorites: Long Residence on the Moon and Short Transition to the Earth

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, Hiroshi; Sakuma, Keisuke [Department of Earth and Planetary Sciences, Nagoya University Nagoya 464-8601 (Japan); Nishiizumi, Kunihiko [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Yoneda, Shigekazu, E-mail: hidaka@eps.nagoya-u.ac.jp [Department of Science and Engineering, National Museum of Nature and Science Tsukuba 305-0005 (Japan)

    2017-06-01

    It is known that most lunar meteorites have complicated cosmic-ray exposure experiences on the Moon and in space. In this study, cosmic-ray irradiation histories of six lunar meteorites, Dhofar 489, Northwest Africa 032 (NWA 032), NWA 479, NWA 482, NWA 2995, and NWA 5000, were characterized from neutron-captured isotopic shifts of Sm and Gd, and from the abundances of long-lived cosmogenic radionuclides like {sup 10}Be, {sup 26}Al, {sup 36}Cl, and {sup 41}Ca. Sm and Gd isotopic data of all of six meteorites show significant isotopic shifts of {sup 149}Sm–{sup 150}Sm and {sup 157}Gd–{sup 158}Gd caused by accumulation of neutron capture reactions due to cosmic-ray irradiation, corresponding to the neutron fluences of (1.3–9.6) × 10{sup 16} n cm{sup −2}. In particular, very large Sm and Gd isotopic shifts of NWA 482 are over those of a lunar regolith 70002, having the largest isotopic shifts among the Apollo regolith samples, corresponding to cosmic-ray exposure duration over 800 million years in the lunar surface (2 π irradiation). Meanwhile, the concentrations of cosmogenic radionuclides for individual six meteorites show the short irradiation time less than one million years as their bodies in space (4 π irradiation). Our data also support the results of previous studies, revealing that most of lunar meteorites have long exposure ages at shallow depths on the Moon and short transit times from the Moon to the Earth.

  17. I-Xe and 40Ar-39Ar dating of silicate from Weekeroo Station and Netschaevo IIE iron meteorites

    International Nuclear Information System (INIS)

    Niemeyer, S.

    1980-01-01

    Silicate inclusions from two IIE iron meteorites were dated by the I-Xe and 40 Ar- 39 Ar techniques. Weekeroo Station, a 'normal' IIE iron, shows no loss of radiogenic 40 Ar at low temperature, and the well defined 40 Ar- 39 Ar plateau yields an age of 4.54 +- 0.03 Byr. The xenon data define a good I-Xe correlation with an age of + 10.9 +- 0.5 Myr relative to Bjurbole. Despite its relatively young age, Weekeroo Station's ( 129 Xe/ 132 Xe)sub(trapped) ratio (= 0.84 +- 0.05) lies significantly below the solar value. Netschaevo silicate has a chondritic composition, unlike 'normal' IIE silicate which is more differentiated. Nevertheless Netschaevo gives a 40 Ar- 39 Ar plateau-age of only 3.79 +- 0.03 Byr, with the xenon data failing to define an I-Xe isochron. Only irons from the IAB and IIE groups contain silicate inclusions, but these two groups differ in many other respects, mostly suggesting that IAB meteorites are more primitive. The I-Xe chronology supports this suggestion inasmuch as Weekeroo Station formed well after IAB silicates. The four silicate-bearing IIE irons which have now been dated can be subdivided into distinct pairs: Weekeroo Station and Colomera formed near the beginning of the solar system, while Netschaevo and Kodaikanal both formed only 3.8 Byr ago. A review of other properties of these meteorites generally supports this subdivision. This work underscores the complexity of the history of IIE meteorites; in particular, an adequate model must account for the formation of two IIE irons at 3.8 Byr without disturbing rare gases in Weekeroo Station. All formation models are quite speculative, but the one which seems best to fit the available evidence postulates two parent bodies: the 3.8 Byr old silicate formed on one parent body, all other IIE material resided in a separate body, and subsequent collision(s) mixed the young silicate with IIE metal. (author)

  18. Element Abundances in Meteorites and the Earth: Implication for the Accretion of Planetary Bodies

    Science.gov (United States)

    Mezger, K.; Vollstaedt, H.; Maltese, A.

    2017-12-01

    Essentially all known inner solar system materials show near chondritic relative abundances of refractory elements and depletion in volatile elements. To a first approximation volatile element depletion correlates with the respective condensation temperature (TC) of the elements. Possible mechanisms for this depletion are incomplete condensation and partial loss by evaporation caused by heating prior to or during the planetesimal accretion. The stable isotope compositions of almost all moderately volatile elements in different meteorite classes show only minor, or no evidence for a Rayleigh-type fractionation that could be attributed to partial condensation or evaporation. The different classes of meteorites also show that the degree of depletion in their parent bodies (i.e. mostly planetesimals) is quite variable, but nevertheless systematic. For primitive and least disturbed carbonaceous chondrites the element depletion pattern is a smooth function of TC. The accessible silicate Earth also shows this general depletion pattern, but in detail it is highly complex and requires differentiation processes that are not solely controlled by TC. If only highly lithophile elements are considered the depletion pattern of the silicate Earth reveals a step function that shows that moderately volatile lithophile elements have abundances that are ca. 0.1 times the chondritic value, irrespective of their TC. This element pattern observed for bulk silicate Earth can be modelled as a mixture of two distinct components: ca. 90% of a strongly reduced planetary body that is depleted in highly volatile elements and ca. 10% of a more volatile element rich and oxidized component. This mixture can account for the apparent Pb- paradox observed in melts derived from the silicate Earth and provides a time constraint for the mixing event, which is ca. 70 My after the beginning of the solar system. This event corresponds to the giant impact that also formed the Moon.

  19. Petrogenesis of Igneous-Textured Clasts in Martian Meteorite Northwest Africa 7034

    Science.gov (United States)

    Santos, A. R.; Agee, C. B.; Humayun, M.; McCubbin, F. M.; Shearer, C. K.

    2016-01-01

    The martian meteorite Northwest Africa 7034 (and pairings) is a breccia that samples a variety of materials from the martian crust. Several previous studies have identified multiple types of igneous-textured clasts within the breccia [1-3], and these clasts have the potential to provide insight into the igneous evolution of Mars. One challenge presented by studying these small rock fragments is the lack of field context for this breccia (i.e., where on Mars it formed), so we do not know how many sources these small rock fragments are derived from or the exact formation his-tory of these sources (i.e., are the sources mantle de-rived melt or melts contaminated by a meteorite impactor on Mars). Our goal in this study is to examine specific igneous-textured clast groups to determine if they are petrogenetically related (i.e., from the same igneous source) and determine more information about their formation history, then use them to derive new insights about the igneous history of Mars. We will focus on the basalt clasts, FTP clasts (named due to their high concentration of iron, titanium, and phosphorous), and mineral fragments described by [1] (Fig. 1). We will examine these materials for evidence of impactor contamination (as proposed for some materials by [2]) or mantle melt derivation. We will also test the petrogenetic models proposed in [1], which are igneous processes that could have occurred regardless of where the melt parental to the clasts was formed. These models include 1) derivation of the FTP clasts from a basalt clast melt through silicate liquid immiscibility (SLI), 2) derivation of the FTP clasts from a basalt clast melt through fractional crystallization, and 3) a lack of petrogenetic relationship between these clast groups. The relationship between the clast groups and the mineral fragments will also be explored.

  20. Intrinsic magnetic properties of L1(0) FeNi obtained from meteorite NWA 6259

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, E; Pinkerton, FE; Kubic, R; Mishra, RK; Bordeaux, N; Mubarok, A; Lewis, LH; Goldstein, JI; Skomski, R; Barmak, K

    2015-05-07

    FeNi having the tetragonal L1(0) crystal structure is a promising new rare-earth-free permanent magnet material. Laboratory synthesis is challenging, however, tetragonal L1(0) FeNi-the mineral "tetrataenite"-has been characterized using specimens found in nickel-iron meteorites. Most notably, the meteorite NWA 6259 recovered from Northwest Africa is 95 vol.% tetrataenite with a composition of 43 at.% Ni. Hysteresis loops were measured as a function of sample orientation on a specimen cut from NWA 6259 in order to rigorously deduce the intrinsic hard magnetic properties of its L1(0) phase. Electron backscatter diffraction showed that NWA 6259 is strongly textured, containing L1(0) grains oriented along any one of the three equivalent cubic directions of the parent fcc structure. The magnetic structure was modeled as a superposition of the three orthonormal uniaxial variants. By simultaneously fitting first-quadrant magnetization data for 13 different orientations of the sample with respect to the applied field direction, the intrinsic magnetic properties were estimated to be saturation magnetization 4 pi M-s = 14.7 kG and anisotropy field H-a = 14.4 kOe. The anisotropy constant K = 0.84 MJ/m(3) is somewhat smaller than the value K = 1.3 MJ/m(3) obtained by earlier researchers from nominally equiatomic FeNi prepared by neutron irradiation accompanied by annealing in a magnetic field, suggesting that higher Ni content (fewer Fe antisite defects) may improve the anisotropy. The fit also indicated that NWA 6259 contains one dominant variant (62% by volume), the remainder of the sample being a second variant, and the third variant being absent altogether. (C) 2015 AIP Publishing LLC.

  1. Intrinsic magnetic properties of L1{sub 0} FeNi obtained from meteorite NWA 6259

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, Eric [MEDA Engineering and Technical Services, Southfield, Michigan 48075 (United States); Pinkerton, Frederick E., E-mail: frederick.e.pinkerton@gm.com; Kubic, Robert; Mishra, Raja K. [Chemical Sciences and Materials Systems Lab, GM R and D Center, Warren, Michigan 48090 (United States); Bordeaux, Nina; Lewis, Laura H. [Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115 (United States); Mubarok, Arif; Goldstein, Joseph I. [Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Skomski, Ralph [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); Barmak, Katayun [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2015-05-07

    FeNi having the tetragonal L1{sub 0} crystal structure is a promising new rare-earth-free permanent magnet material. Laboratory synthesis is challenging, however, tetragonal L1{sub 0} FeNi—the mineral “tetrataenite”—has been characterized using specimens found in nickel-iron meteorites. Most notably, the meteorite NWA 6259 recovered from Northwest Africa is 95 vol. % tetrataenite with a composition of 43 at. % Ni. Hysteresis loops were measured as a function of sample orientation on a specimen cut from NWA 6259 in order to rigorously deduce the intrinsic hard magnetic properties of its L1{sub 0} phase. Electron backscatter diffraction showed that NWA 6259 is strongly textured, containing L1{sub 0} grains oriented along any one of the three equivalent cubic directions of the parent fcc structure. The magnetic structure was modeled as a superposition of the three orthonormal uniaxial variants. By simultaneously fitting first-quadrant magnetization data for 13 different orientations of the sample with respect to the applied field direction, the intrinsic magnetic properties were estimated to be saturation magnetization 4πM{sub s} = 14.7 kG and anisotropy field H{sub a} = 14.4 kOe. The anisotropy constant K = 0.84 MJ/m{sup 3} is somewhat smaller than the value K = 1.3 MJ/m{sup 3} obtained by earlier researchers from nominally equiatomic FeNi prepared by neutron irradiation accompanied by annealing in a magnetic field, suggesting that higher Ni content (fewer Fe antisite defects) may improve the anisotropy. The fit also indicated that NWA 6259 contains one dominant variant (62% by volume), the remainder of the sample being a second variant, and the third variant being absent altogether.

  2. Intrinsic magnetic properties of L10 FeNi obtained from meteorite NWA 6259

    International Nuclear Information System (INIS)

    Poirier, Eric; Pinkerton, Frederick E.; Kubic, Robert; Mishra, Raja K.; Bordeaux, Nina; Lewis, Laura H.; Mubarok, Arif; Goldstein, Joseph I.; Skomski, Ralph; Barmak, Katayun

    2015-01-01

    FeNi having the tetragonal L1 0 crystal structure is a promising new rare-earth-free permanent magnet material. Laboratory synthesis is challenging, however, tetragonal L1 0 FeNi—the mineral “tetrataenite”—has been characterized using specimens found in nickel-iron meteorites. Most notably, the meteorite NWA 6259 recovered from Northwest Africa is 95 vol. % tetrataenite with a composition of 43 at. % Ni. Hysteresis loops were measured as a function of sample orientation on a specimen cut from NWA 6259 in order to rigorously deduce the intrinsic hard magnetic properties of its L1 0 phase. Electron backscatter diffraction showed that NWA 6259 is strongly textured, containing L1 0 grains oriented along any one of the three equivalent cubic directions of the parent fcc structure. The magnetic structure was modeled as a superposition of the three orthonormal uniaxial variants. By simultaneously fitting first-quadrant magnetization data for 13 different orientations of the sample with respect to the applied field direction, the intrinsic magnetic properties were estimated to be saturation magnetization 4πM s  = 14.7 kG and anisotropy field H a  = 14.4 kOe. The anisotropy constant K = 0.84 MJ/m 3 is somewhat smaller than the value K = 1.3 MJ/m 3 obtained by earlier researchers from nominally equiatomic FeNi prepared by neutron irradiation accompanied by annealing in a magnetic field, suggesting that higher Ni content (fewer Fe antisite defects) may improve the anisotropy. The fit also indicated that NWA 6259 contains one dominant variant (62% by volume), the remainder of the sample being a second variant, and the third variant being absent altogether

  3. A 6-cm deep sky survey

    International Nuclear Information System (INIS)

    Fomalont, E.B.; Kellermann, K.I.; Wall, J.V.

    1983-01-01

    In order to extend radio source counts to lower flux density, the authors have used the VLA to survey a small region of sky at 4.885 GHz (6 cm) to a limiting flux density of 50 μJy. Details of this deep survey are given in the paper by kellermann et al. (these proceedings). In addition, they have observed 10 other nearby fields to a limiting flux density of 350 μJy in order to provide better statistics on sources of intermediate flux density. (Auth.)

  4. REDUNDANT ARRAY CONFIGURATIONS FOR 21 cm COSMOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, Joshua S.; Parsons, Aaron R., E-mail: jsdillon@berkeley.edu [Department of Astronomy, UC Berkeley, Berkeley, CA (United States)

    2016-08-01

    Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being designed and built to meet these challenges, drawing lessons from first-generation experiments that showed the benefits of densely packed, highly redundant arrays—in which the same mode on the sky is sampled by many antenna pairs—for achieving high sensitivity, precise calibration, and robust foreground mitigation. In this work, we focus on the Hydrogen Epoch of Reionization Array (HERA) as an interferometer with a dense, redundant core designed following these lessons to be optimized for 21 cm cosmology. We show how modestly supplementing or modifying a compact design like HERA’s can still deliver high sensitivity while enhancing strategies for calibration and foreground mitigation. In particular, we compare the imaging capability of several array configurations, both instantaneously (to address instrumental and ionospheric effects) and with rotation synthesis (for foreground removal). We also examine the effects that configuration has on calibratability using instantaneous redundancy. We find that improved imaging with sub-aperture sampling via “off-grid” antennas and increased angular resolution via far-flung “outrigger” antennas is possible with a redundantly calibratable array configuration.

  5. Separation and recovery of Cm from Cm-Pu mixed oxide samples containing Am impurity

    International Nuclear Information System (INIS)

    Hirokazu Hayashi; Hiromichi Hagiya; Mitsuo Akabori; Yasuji Morita; Kazuo Minato

    2013-01-01

    Curium was separated and recovered as an oxalate from a Cm-Pu mixed oxide which had been a 244 Cm oxide sample prepared more than 40 years ago and the ratio of 244 Cm to 240 Pu was estimated to 0.2:0.8. Radiochemical analyses of the solution prepared by dissolving the Cm-Pu mixed oxide in nitric acid revealed that the oxide contained about 1 at% of 243 Am impurity. To obtain high purity curium solution, plutonium and americium were removed from the solution by an anion exchange method and by chromatographic separation using tertiary pyridine resin embedded in silica beads with nitric acid/methanol mixed solution, respectively. Curium oxalate, a precursor compound of curium oxide, was prepared from the purified curium solution. 11.9 mg of Cm oxalate having some amounts of impurities, which are 243 Am (5.4 at%) and 240 Pu (0.3 at%) was obtained without Am removal procedure. Meanwhile, 12.0 mg of Cm oxalate (99.8 at% over actinides) was obtained with the procedure including Am removals. Both of the obtained Cm oxalate sample were supplied for the syntheses and measurements of the thermochemical properties of curium compounds. (author)

  6. Spectral reflectance "deconstruction" of the Murchison CM2 carbonaceous chondrite and implications for spectroscopic investigations of dark asteroids

    Science.gov (United States)

    Cloutis, Edward A.; Pietrasz, Valerie B.; Kiddell, Cain; Izawa, Matthew R. M.; Vernazza, Pierre; Burbine, Thomas H.; DeMeo, Francesca; Tait, Kimberly T.; Bell, James F.; Mann, Paul; Applin, Daniel M.; Reddy, Vishnu

    2018-05-01

    Carbonaceous chondrites (CCs) are important materials for understanding the early evolution of the solar system and delivery of volatiles and organic material to the early Earth. Presumed CC-like asteroids are also the targets of two current sample return missions: OSIRIS-REx to asteroid Bennu and Hayabusa-2 to asteroid Ryugu, and the Dawn orbital mission at asteroid Ceres. To improve our ability to identify and characterize CM2 CC-type parent bodies, we have examined how factors such as particle size, particle packing, and viewing geometry affect reflectance spectra of the Murchison CM2 CC. The derived relationships have implications for disc-resolved examinations of dark asteroids and sampleability. It has been found that reflectance spectra of slabs are more blue-sloped (reflectance decreasing toward longer wavelengths as measured by the 1.8/0.6 μm reflectance ratio), and generally darker, than powdered sample spectra. Decreasing the maximum grain size of a powdered sample results in progressively brighter and more red-sloped spectra. Decreasing the average grain size of a powdered sample results in a decrease in diagnostic absorption band depths, and redder and brighter spectra. Decreasing porosity of powders and variations in surface texture result in spectral changes that may be different as a function of viewing geometry. Increasing thickness of loose dust on a denser powdered substrate leads to a decrease in absorption band depths. Changes in viewing geometry lead to different changes in spectral metrics depending on whether the spectra are acquired in backscatter or forward-scatter geometries. In backscattered geometry, increasing phase angle leads to an initial increase and then decrease in spectral slope, and a general decrease in visible region reflectance and absorption band depths, and frequent decreases in absorption band minima positions. In forward scattering geometry, increasing phase angle leads to small non-systematic changes in spectral slope

  7. The fate or organic matter during planetary accretion - Preliminary studies of the organic chemistry of experimentally shocked Murchison meteorite

    Science.gov (United States)

    Tingle, Tracy N.; Tyburczy, James A.; Ahrens, Thomas J.; Becker, Christopher H.

    1992-01-01

    The fate of organic matter in carbonaceous meteorites during hypervelocity (1-2 km/sec) impacts is investigated using results of experiments in which three samples of the Murchison (CM2) carbonaceous chondrite were shocked to 19, 20, and 36 GPa and analyzed by highly sensitive thermal-desorption photoionization mass spectrometry (SALI). The thermal-desorptive SALI mass spectra of unshocked CM2 material revealed presence of indigenous aliphatic, aromatic, sulfur, and organosulfur compounds, and samples shocked to about 20 GPa showed little or no loss of organic matter. On the other hand, samples shocked to 36 GPa exhibited about 70 percent loss of organic material and a lower alkene/alkane ratio than did the starting material. The results suggest that it is unlikely that the indigenous organic matter in carbonaceous chondritelike planetesimals could have survived the impact on the earth in the later stages of earth's accretion.

  8. Nucleation of the Widmanstatten Pattern in Iron Meteorites

    Science.gov (United States)

    Yang, J.; Goldstein, J. I.

    2004-01-01

    The Widmanstatten pattern develops at low temperatures during the evolution of the asteroids. We have studied the origin of the Widmanstatten pattern in order to obtain metallographic cooling rates in the temperature range (approx. 700 to 300 deg C). This paper summarizes our recent evaluation of the various mechanisms for the formation of the Widmanstatten pattern. All chemical groups of the iron meteorites are considered. We also propose a new mechanism for the formation of the Widmanstatten pattern in the low P metal phase of iron, stony-iron and stony meteorites. The results of this evaluation enables us to more accurately determine metallographic cooling rates particularly when incorporated with other recent advances in Fe-Ni and Fe-Ni (P saturated) phase diagrams and interdiffusion coefficients.

  9. Chemical Structure of Insoluble Organic Matter of Meteorites

    Science.gov (United States)

    Derenne, S.; Robert, F.; Binet, L.; Gourier, D.; Rouzaud, J.-N.; Largeau, C.

    A detailed knowledge of the insoluble organic matter (IOM) of the meteorites is essential to estimate to what extent the interstellar organic matter was preserved during the formation of the solar system and to decipher the synthetic pathways of this matter in space. Although predominant, the insoluble organic fraction has been much less extensively studied than soluble one due to specific analytical difficulties. The present work reports the examination of the IOM of two carbonaceous meteorites, Orgueil and Murchison through a number of various spectroscopic and microscopic methods, i. e. XANES for sulphur, carbon and nitrogen, solid state 13C NMR, electron paramagnetic resonance, electron nuclear double resonance and high resolution transmission electron microscopy.

  10. Stardust from meteorites an introduction to presolar grains

    CERN Document Server

    Lugaro, Maria

    2005-01-01

    The study of presolar meteoritic grains is a new inter-disciplinary field that brings together topics from nuclear physics to astronomy and chemistry. Traditionally, most of the information about the cosmos has been gathered by observing light through telescopes. However, with the recent discovery that some dust grains extracted from primitive meteorites were produced in stellar environments, we now have the opportunity to gather information about stars and our Galaxy from the laboratory analysis of tiny pieces of stardust. Stellar grains represent a unique and fascinating subject of study. Their analysis is a breakthrough in research on stellar nucleosynthesis and the origin of the elements. While a number of specialized reviews exist on the topic, this book is the first work that brings together in a unified and accessible manner the background knowledge necessary for the study of presolar grains together with up-to-date discoveries in the field. The book includes exercise questions and answers, an extensiv...

  11. Pairing Relationships Among Feldspathic Lunar Meteorites from Miller Range, Antarctica

    Science.gov (United States)

    Zeigler, Ryan A.; Korotev, R. L.; Jolliff, B. L.

    2012-01-01

    The Miller Range ice fields have been amongst the most prolific for lunar meteorites that ANSMET has searched [1-3]. Six different stones have been recovered during the 2005, 2007, and 2009 field seasons: MIL 05035 (142 g), MIL 07006 (1.4 g), MIL 090034 (196 g), MIL 090036 (245 g), MIL 090070 (137 g), and MIL 090075 (144 g). Of these, the five stones collected during the 2007 and 2009 seasons are feldspathic breccias. Previous work on the Miller Range feldspathic lunar meteorites (FLMs) has suggested that they are not all paired with each other [4-5]. Here we examine the pairing relationships among the Miller Range FLMs using petrography in concert with traceand major-element compositions.

  12. Chladniite: A New Mineral Honoring the Father of Meteoritics

    Science.gov (United States)

    McCoy, T. J.; Steele, I. M.; Keil, K.; Leonard, B. F.; Endress, M.

    1993-07-01

    The IIICD irons are a small group of meteorites, three of which (Maltahohe, Carlton, and Dayton) contain silicate-bearing inclusions rich in troilite, graphite, schreibersite, and phosphates [1]. The Na,Ca,Mg-rich phosphates bnanite and panethite were first described in Dayton [2]. We have discovered a new mineral, Na(sub)2CaMg(sub)7(PO(sub)4)(sub)6, as a single grain within a silicate-bearing inclusion in the Carlton (IIICD) iron meteorite. The mineral and mineral name have been approved by the Commission on New Minerals and Mineral Names of the International Mineralogical Association. Chladniite occurs as a single grain near the edge of a silicate-bearing inclusion in polished section USNM 2707. This inclusion is dominated by chlorapatite and contains olivine, pyroxene, plagioclase, schreibersite, and troilite. Chladniite occurs as a single, massive grain (975 x 175 micrometers) and is cross-cut by hydrated iron oxides of terrestrial origin. In polished section, it is gray, dark, and weakly anisotropic. Cleavage is rhomboidal in plan and very likely rhombohedral in three dimension. The formula for chladniite (derived from five microprobe analyses) is Na(sub)1.77Si(sub)0.08 Ca(sub)0.98(Mg(sub)6.96Fe(sub)0.26Mn(sub)0.04)(sub)Sigma = 7.26(Po(sub)0.98 O(sub)4)(sub)6. The idealized formula is Na(sub)2CaMg(sub)7(PO(sub)4)(sub)6. Chladniite is related to two rare minerals, fillowite [3] and johnsomervilleite [4], where fillowite is the Mn-dominated and johnsomervilleite the Fe-dominated analog of chladniite. The unique occurrence of chladniite, the relatively small size of the grain, and the presence of terrestrial weathering veins all presented challenges for removing material for X-ray studies. A 30-micrometer-diameter spindle of material was removed after microdrilling a shallow trench and breaking the spindle with a surgical scalpel. Studies were performed using both a Gandolfi camera to obtain a powder pattern and a four-circle diffractometer to determine the unit

  13. Long-lived magnetism on chondrite parent bodies

    Science.gov (United States)

    Shah, Jay; Bates, Helena C.; Muxworthy, Adrian R.; Hezel, Dominik C.; Russell, Sara S.; Genge, Matthew J.

    2017-10-01

    We present evidence for both early- and late-stage magnetic activity on the CV and L/LL parent bodies respectively from chondrules in Vigarano and Bjurböle. Using micro-CT scans to re-orientate chondrules to their in-situ positions, we present a new micron-scale protocol for the paleomagnetic conglomerate test. The paleomagnetic conglomerate test determines at 95% confidence, whether clasts within a conglomerate were magnetized before or after agglomeration, i.e., for a chondritic meteorite whether the chondrules carry a pre- or post-accretionary remanent magnetization. We found both meteorites passed the conglomerate test, i.e., the chondrules had randomly orientated magnetizations. Vigarano's heterogeneous magnetization is likely of shock origin, due to the 10 to 20 GPa impacts that brecciated its precursor material on the parent body and transported it to re-accrete as the Vigarano breccia. The magnetization was likely acquired during the break-up of the original body, indicating a CV parent body dynamo was active ∼9 Ma after Solar System formation. Bjurböle's magnetization is due to tetrataenite, which transformed from taenite as the parent body cooled to below 320 °C, when an ambient magnetic field imparted a remanence. We argue either the high intrinsic anisotropy of tetrataenite or brecciation on the parent body manifests as a randomly orientated distribution, and a L/LL parent body dynamo must have been active at least 80 to 140 Ma after peak metamorphism. Primitive chondrites did not originate from entirely primitive, never molten and/or differentiated parent bodies. Primitive chondrite parent bodies consisted of a differentiated interior sustaining a long-lived magnetic dynamo, encrusted by a layer of incrementally accreted primitive meteoritic material. The different ages of carbonaceous and ordinary chondrite parent bodies might indicate a general difference between carbonaceous and ordinary chondrite parent bodies, and/or formation location in the

  14. Investigations on Important Properties of the 10 cm x 10 cm GEM Prototype

    CERN Document Server

    Saenboonruang, Kiadtisak; Kulasri, Kittipong; Ritthirong, Anawat

    2015-01-01

    The Gas Electron Multiplier (GEM) detector is one of promising particle and radiation detectors that has been improved greatly from previous gas detectors. The improvement includes better spatial resolutions, higher detection rate capabilities, and flexibilities in designs. In particular, the 10 cm x 10 cm GEM prototype is designed and provided by the Gas Detectors Development group (GDD) at CERN, Switzerland. With its simplicity in operations and designs, while still maintaining high qualities, the GEM prototype is suitable for both start-up and advanced researches. This article aims to report the investigations on some important properties of the 10 cm x 10 cm GEM detector using current measurement and signal counting. Results have shown that gains of the GEM prototype exponentially increase as voltage supplied to the detector increases, while the detector reaches full efficiency (plateau region) when the voltage is greater than 4100 V. In terms of signal sharing between X and Y strips of the readout, X str...

  15. Compact modular BWR (CM-BWR)

    International Nuclear Information System (INIS)

    Fennern, Larry; Boardman, Charles; Carroll, Douglas G.; Hida, Takahiko

    2003-01-01

    A preliminary assessment has shown that a small 350 MWe BWR reactor can be placed within a close fitting steel containment vessel that is 7.1 meters inside diameter. This allows the technology and manufacturing capability currently used to fabricate large ABWR reactor vessels to be used to provide a factory fabricated containment vessel for a 350 MWe BWR. When a close fitted steel containment is combined with a passive closed loop isolation condenser system and a natural circulating reactor system that contains a large water inventory, primary system leaks cannot uncover the core. This eliminates many of the safety systems needed in response to a LOCA that are common to large, conventional plant designs including. Emergency Core Flooding, Automatic Depressurization System, Active Residual Heat Removal, Safety Related Auxiliary Cooling, Safety Related Diesel Generators, Hydrogen Re-Combiners, Ex-vessel Core Retention and Cooling. By fabricating the containment in a factory and eliminating most of the conventional safety systems, the construction schedule is shortened and the capital cost reduced to levels that would not otherwise be possible for a relatively small modular BWR. This makes the CM-BWR a candidate for applications where smaller incremental power additions are desired relative to a large ALWR or where the local infrastructure is not able to accommodate a conventional ALWR plant rated at 1350 MWe or more. This paper presents a preliminary design description of a Compact Modular BWR (CM-BWR) whose design features dramatically reduce the size and cost of the reactor building and associated safety systems. (author)

  16. Preliminary Study of Meteorite and Tektite using Nuclear Techniques

    International Nuclear Information System (INIS)

    Khaweerat, Sasiphan; Tangpitayakul, Pisarn; Pimjun, Surapong; Chongkum, Somporn; Sangsuriya, Sineenart; Wiseatsri, Pojanee

    2003-06-01

    The discoveries of suspicious meteorite or tektite around Chaiyapum province and surrounding area were sent to Physics Division, Office of Atoms for Peace (OAP). Fourteen samples were analyzed by 3 nuclear techniques; the measurement of natural radiation, x-ray fluorescence analysis and neutron activation analysis. The result shows that the samples can be classified according to the level of natural radiation, the elemental composition and there quantity

  17. Alteration of Sedimentary Clasts in Martian Meteorite Northwest Africa 7034

    Science.gov (United States)

    McCubbin, F. M.; Tartese, R.; Santos, A. R.; Domokos, G.; Muttik, N.; Szabo, T.; Vazquez, J.; Boyce, J. W.; Keller, L. P.; Jerolmack, D. J.; hide

    2014-01-01

    The martian meteorite Northwest Africa (NWA) 7034 and pairings represent the first brecciated hand sample available for study from the martian surface [1]. Detailed investigations of NWA 7034 have revealed substantial lithologic diversity among the clasts [2-3], making NWA 7034 a polymict breccia. NWA 7034 consists of igneous clasts, impact-melt clasts, and "sedimentary" clasts represented by prior generations of brecciated material. In the present study we conduct a detailed textural and geochemical analysis of the sedimentary clasts.

  18. Isotopes produced by galactic cosmic rays in iron meteorites

    International Nuclear Information System (INIS)

    Birck, J.L.; Allegre, C.J.

    1985-01-01

    The elements Li, Mg, K, Ca, Ti, V, Cr have been investigated in the iron meteorites Grant and Carbo. Their isotopic ratios show clearly the effects of spallation by galactic cosmic rays. Our experimental technique allows us to determine the concentration of spallation products with a precision close to 1 per mil for a number of isotopes. The effects of shielding are clearly evidenced in the calcium data and the exposure ages are calculated by using the 40 K measurements

  19. PF120916 Piecki fireball and Reszel meteorite fall

    Science.gov (United States)

    Olech, A.; Żołądek, P.; Tymiński, Z.; Stolarz, M.; Wiśniewski, M.; Bęben, M.; Lewandowski, T.; Polak, K.; Raj, A.; Zaręba, P.

    2017-06-01

    On September 12, 2016, at 21:44:07 UT, a -9.2±0.5 mag fireball appeared over northeastern Poland. The precise orbit and atmospheric trajectory of the event are presented, based on the data collected by six video stations of the Polish Fireball Network (PFN). The PF120916 Piecki fireball entered the Earth's atmosphere with the velocity of 16.7±0.3 km/s and started to shine at a height of 81.9 ± 0.3 km. Clear deceleration started after first three seconds of the flight, and the terminal velocity of the meteor was only 5.0±0.3 km/s at a height of 26.0 ± 0.2 km. Such a low value of the terminal velocity indicates that fragments with the total mass of around 10-15 kg could survive the atmospheric passage and cause fall of the meteorites. The predicted area of possible meteorite impact is computed and it is located south of Reszel city at the Warmian-Masurian region. The impact area was extensively searched by experienced groups of meteorite hunters, but without any success.

  20. Indigenous Carbonaceous Matter in the Nakhla Mars Meteorite

    Science.gov (United States)

    Clemett, S. J.; Thomas-Keprta, K. L.; Rahman, Z.; Le, L.; Wentworth, S. J.; Gibson, E. K.; McKay, D. S.

    2016-01-01

    Detailed microanalysis of the Martian meteorite Nakhla has shown there are morphologically distinct carbonaceous features spatially associated with low-T aqueous alteration phases including salts and id-dingsite. A comprehensive suite of analytical instrumentation including optical microscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, focused ion beam (FIB) microscopy, transmission electron microscopy (TEM), two-step laser mass spectrometry (mu-L(sup 2)MS), laser mu-Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and nanoscale secondary ion mass spectrometry (NanoSIMS) are being used to characterize the carbonaceous matter and host mineralogy. The search for carbonaceous matter on Mars has proved challenging. Viking Landers failed to unambiguously detect simple organics at either of the two landing sites although the Martian surface is estimated to have acquired at least 10(exp15) kg of C as a consequence of meteoritic accretion over the last several Ga. The dearth of organics at the Martian surface has been attributed to various oxidative processes including UV photolysis and peroxide activity. Consequently, investigations of Martian organics need to be focused on the sub-surface regolith where such surface processes are either severely attenuated or absent. Fortuitously since Martian meteorites are derived from buried regolith materials they provide a unique opportunity to study Martian organic geochemistry.

  1. Sparking young minds with Moon rocks and meteorites

    Science.gov (United States)

    Taylor, G. Jeffrey; Lindstrom, Marilyn M.

    1993-01-01

    What could be more exciting than seeing pieces of other worlds? The Apollo program left a legacy of astounding accomplishments and precious samples. Part of the thrill of those lunar missions is brought to schools by the lunar sample educational disks, which contain artifacts of six piloted trips to the Moon. Johnson Space Center (JSC) is preparing 100 new educational disks containing pieces of meteorites collected in Antarctica. These represent chunks of several different asteroids, that were collected in one of the most remote, forbidding environments on Earth. These pieces of the Moon and asteroids represent the products of basic planetary processes (solar nebular processes, initial differentiation, volcanism, and impact), and, in turn, these processes are controlled by basic physical and chemical processes (energy, energy transfer, melting, buoyancy, etc.). Thus, the lunar and meteorite sample disks have enormous educational potential. New educational materials are being developed to accompany the disks. Present materials are not as effective as they could be, especially in relating samples to processes and to other types of data such as spectral studies and photogeology. Furthermore, the materials are out of date. New background materials will be produced for teachers, assembling slide sets with extensive captions, and devising numerous hands-on classroom activities to do while the disks are at a school and before and after they arrive. The classroom activities will be developed by teams of experienced teachers working with lunar and meteorite experts.

  2. Magnetic properties of tetrataenite-rich meteorites. Pt. 2

    International Nuclear Information System (INIS)

    Nagata, T.; Funaki, M.; Danon, J.

    1985-01-01

    Magnetic hysteresis and thermomagnetic characteristics of St. Severin (LL 6 ), Appley Bridge (LL 6 ) and Tuxtuac (LL 5 ) chondrites, which contain tetrataenite in their metallic components, are measured and analyzed in comparison with another tetrataenite-rich chondrite, Yamato 74160. The magnetic properties of tetrataenite-rich meteorites are characterized by (a) high magnetic coercive force (H sub(C)) which amounts to 520 Oe for St. Severin and 160 Oe for Appley Bridge, (b) essential flatness up to about 500 0 C and then a sharp irreversible drop down to Curie point of the first-run heating thermomagnetic curve. Both characteristic features are broken down to the ordinary features of disordered taenite by a breakdown of tetrataenite structure at elevated temperatures beyond the order-disorder transition temperature. The natural remanent magnetization (NRM) of tetrataenite-rich meteorites is extremely stable against AF-demagnetization and other magnetic disturbances because of the high magnetic coercivity of tetrataenite. The breakdown processes of ordered tetrataenite structure by heat treatments are experimentally pursued for the purpose of research of a possible formation process of tetrataenite phase in meteorites. (Author) [pt

  3. Molecular Asymmetry in Prebiotic Chemistry: An Account from Meteorites

    Directory of Open Access Journals (Sweden)

    Sandra Pizzarello

    2016-04-01

    Full Text Available Carbonaceous Chondrite (CC meteorites are fragments of asteroids, solar planetesimals that never became large enough to separate matter by their density, like terrestrial planets. CC contains various amounts of organic carbon and carry a record of chemical evolution as it came to be in the Solar System, at the time the Earth was formed and before the origins of life. We review this record as it pertains to the chiral asymmetry determined for several organic compounds in CC, which reaches a broad molecular distribution and enantiomeric excesses of up to 50%–60%. Because homochirality is an indispensable attribute of extant polymers and these meteoritic enantiomeric excesses are still, to date, the only case of chiral asymmetry in organic molecules measured outside the biosphere, the possibility of an exogenous delivery of primed prebiotic compounds to early Earth from meteorites is often proposed. Whether this exogenous delivery held a chiral advantage in molecular evolution remains an open question, as many others regarding the origins of life are.

  4. Irradiated Benzene Ice Provides Clues to Meteoritic Organic Chemistry

    Science.gov (United States)

    Callahan, Michael Patrick; Gerakines, Perry Alexander; Martin, Mildred G.; Hudson, Reggie L.; Peeters, Zan

    2013-01-01

    Aromatic hydrocarbons account for a significant portion of the organic matter in carbonaceous chondrite meteorites, as a component of both the low molecular weight, solvent-extractable compounds and the insoluble organic macromolecular material. Previous work has suggested that the aromatic compounds in carbonaceous chondrites may have originated in the radiation-processed icy mantles of interstellar dust grains. Here we report new studies of the organic residue made from benzene irradiated at 19 K by 0.8 MeV protons. Polyphenyls with up to four rings were unambiguously identified in the residue by gas chromatography-mass spectrometry. Atmospheric pressure photoionization Fourier transform mass spectrometry was used to determine molecular composition, and accurate mass measurements suggested the presence of polyphenyls, partially hydrogenated polyphenyls, and other complex aromatic compounds. The profile of low molecular weight compounds in the residue compared well with extracts from the Murchison and Orgueil meteorites. These results are consistent with the possibility that solid phase radiation chemistry of benzene produced some of the complex aromatics found in meteorites.

  5. Purple Salt and Tiny Drops of Water in Meteorites

    Science.gov (United States)

    Taylor, G. J.

    1999-12-01

    Some meteorites, especially those called carbonaceous chondrites, have been greatly affected by reaction with water on the asteroids in which they formed. These reactions, which took place during the first 10 million years of the Solar System's history, formed assorted water-bearing minerals, but nobody has found any of the water that caused the alteration. Nobody, that is, until now. Michael Zolensky and team of scientists from the Johnson Space Center in Houston and Virginia Tech (Blacksburg, Virginia) discovered strikingly purple sodium chloride (table salt) crystals in two meteorites. The salt contains tiny droplets of salt water (with some other elements dissolved in it). The salt is as old as the Solar System, so the water trapped inside the salt is also ancient. It might give us clues to the nature of the water that so pervasively altered carbonaceous chondrites and formed oceans on Europa and perhaps other icy satellites. However, how the salt got into the two meteorites and how it trapped the water remains a mystery - at least for now.

  6. A Method for Estimating Meteorite Fall Mass from Weather Radar Data

    Science.gov (United States)

    Laird, C.; Fries, M.; Matson, R.

    2017-01-01

    Techniques such as weather RADAR, seismometers, and all-sky cameras allow new insights concerning the physics of meteorite fall dynamics and fragmentation during "dark flight", the period of time between the end of the meteor's luminous flight and the concluding impact on the Earth's surface. Understanding dark flight dynamics enables us to rapidly analyze the characteristics of new meteorite falls. This analysis will provide essential information to meteorite hunters to optimize recovery, increasing the frequency and total mass of scientifically important freshly-fallen meteorites available to the scientific community. We have developed a mathematical method to estimate meteorite fall mass using reflectivity data as recorded by National Oceanic and Atmospheric Administration (NOAA) Next Generation RADAR (NEXRAD) stations. This study analyzed eleven official and one unofficial meteorite falls in the United States and Canada to achieve this purpose.

  7. Utilizing Weather RADAR for Rapid Location of Meteorite Falls and Space Debris Re-Entry

    Science.gov (United States)

    Fries, Marc D.

    2016-01-01

    This activity utilizes existing NOAA weather RADAR imagery to locate meteorite falls and space debris falls. The near-real-time availability and spatial accuracy of these data allow rapid recovery of material from both meteorite falls and space debris re-entry events. To date, at least 22 meteorite fall recoveries have benefitted from RADAR detection and fall modeling, and multiple debris re-entry events over the United States have been observed in unprecedented detail.

  8. A Raman Study of Carbonates and Organic Contents in Five CM Chondrites

    Science.gov (United States)

    Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Farley, C.; Cheung, J. C. H.

    2016-01-01

    Carbonates comprise the second most abundant class of carbon-bearing phases in carbonaceous chondrites after organic matter (approximately 2 wt.%), followed by other C-bearing phases such as diamond, silicon carbide, and graphite. Therefore, understanding the abundances of carbonates and the associated organic matter provide critical insight into the genesis of major carbonaceous components in chondritic materials. Carbonates in CM chondrites mostly occur as calcite (of varying composition) and dolomite. Properly performed, Raman spectroscopy provides a non-destructive technique for characterizing meteorite mineralogy and organic chemistry. It is sensitive to many carbonaceous phases, allows the differentiation of organic from inorganic materials, and the interpretation of their spatial distribution. Here, with the use of Raman spectroscopy, we determine the structure of the insoluble organic matter (IOM) in the matrix and carbonate phases in five CM chondrites: Jbilet Winselwan, Murchison, Nogoya, Santa Cruz, and Wisconsin Range (WIS) 91600, and interpret the relative timing of carbonate precipitation and the extent of the associated alteration events.

  9. Asteroids and Meteorites from Venus? Only the Earth Goddess Knows

    Science.gov (United States)

    Dones, Henry; Zahnle, Kevin J.; Alvarellos, José L.

    2018-04-01

    No meteorites from Venus have been found; indeed, some find theirexistence unlikely because of the perceived difficulty of launchingrocks at speeds above 10 km/s and traversing the planet's 93 baratmosphere. [1] Nonetheless, we keep hope alive, since cosmochemistssay they can identify Cytherean meteorites, should candidates be found[2]. Gladman et al. [3] modeled the exchange of impact ejecta betweenthe terrestrial planets, but did not consider meteorites launched fromVenus in any detail. At the time of Gladman's work, no asteroids thatremained entirely within Earth's orbit were known. 14 suchEarth-interior objects with good orbits have now been discovered, andare known as Atiras, for the Pawnee goddess of the Earth. The largestknown member of the class is 163693 Atira, a binary whose componentshave diameters of approximately 4.8 and 1 km. Discovery of Atiras isvery incomplete because they can only be seen at small solarelongations [4]. Greenstreet et al. [5] modeled the orbitaldistribution of Atiras from main-belt asteroidal and cometary sourceregions, while Ribeiro et al. [6] mapped the stability region ofhypothetical Atiras and integrated the orbits of clones of 12 realAtiras for 1 million years. 97% of the clones survived for 1 Myrimpact with Venus was the most common fate of those that met theirends. We have performed orbital integrations of 1000 clones of each ofthe known Atiras, and of hypothetical ejecta that escape Venus afterasteroid impacts, for 10-100 Myr. The latter calculations usetechniques like those of Alvarellos et al. [7] and Zahnle et al. [8]for transfer amongst Jupiter's galilean satellites. Our goals are toestimate the fraction of Atiras that are ejecta launched from Venus,the time spent in space by hypothetical meteorites from Venus, and therate at which such meteorites strike the Earth.[1] Gilmore M., et al (2017). Space Sci. Rev. 212, 1511. [2] JourdanF., Eroglu E. (2017). MAPS 52, 884. [3] Gladman B.J., etal. (1996). Science 271, 1387. [4

  10. Calcium and titanium isotopes in refractory inclusions from CM, CO, and CR chondrites

    Science.gov (United States)

    Kööp, Levke; Davis, Andrew M.; Krot, Alexander N.; Nagashima, Kazuhide; Simon, Steven B.

    2018-05-01

    Previous studies have shown that CV and CM chondrites incorporated Ca, Al-rich inclusions (CAIs) with different isotopic characteristics, which may represent different snapshots in the isotopic evolution of the early Solar System. To better understand how the isotopic characteristics of CAIs vary between different chondrite groups, we have studied calcium and titanium isotopes in CAIs from CM, CO, and CR chondrites. We show that all three chondrite groups contain CAIs with large anomalies in 48Ca and/or 50Ti (10s of ‰ or 100s of ε-units) as well as CAIs with no anomalies resolved beyond measurement uncertainties. Isotopically, the anomalous CO and CR chondrite CAIs resemble the platy hibonite crystals (PLACs) from CM chondrites, but they are more mineralogically complex. The new data are consistent with the well-established mutual exclusivity relationship between incorporation of 26Al and the presence of large anomalies in 48Ca and 50Ti. The two highly anomalous CO chondrite CAIs have correlated anomalies in 46Ti and 50Ti, while most other highly anomalous CAIs do not. This result could indicate that the reservoir with coupled 46Ti and 50Ti that was sampled by bulk meteorites and CV chondrite CAIs already existed before arrival and/or homogeneous distribution of 26Al in the protoplanetary disk. Among the studied CM chondrite CAIs are ten spinel-hibonite inclusions (SHIBs) with known oxygen isotopic compositions. Our results show that these objects sampled a reservoir that was well-mixed in oxygen, calcium, and titanium isotopes. We further show that SHIBs tend to be slightly enriched in the heavy calcium isotopes, suggesting that their formation history was different from CV chondrite CAIs.

  11. A complex of meteorite-forming bodies (the Innisfree - Ridgedale family).

    Science.gov (United States)

    Shestaka, I. S.

    1994-12-01

    For the first time a swarm of meteorite-forming bodies was identified. Yearly this swarm's orbit approaches the Earth's orbit in early February. This swarm contains the Innisfree and Ridgedale fireballs, 9 small meteoric swarms, several asteroids and 12 fireballs photographed by the cameras of the Prairie Network and Canadian Meteorite Observation and Discovery Project. The discovery of this complex, intensive bombardments of the Moon's surface recorded by means of seismographs left on the Moon, the analysis of the time distributions of meteorite falls on the Earth and other established facts confirm the existence of swarms of meteorite-forming bodies which are crossing the Earth's orbit.

  12. A Peltier-based freeze-thaw device for meteorite disaggregation

    Science.gov (United States)

    Ogliore, R. C.

    2018-02-01

    A Peltier-based freeze-thaw device for the disaggregation of meteorite or other rock samples is described. Meteorite samples are kept in six water-filled cavities inside a thin-walled Al block. This block is held between two Peltier coolers that are automatically cycled between cooling and warming. One cycle takes approximately 20 min. The device can run unattended for months, allowing for ˜10 000 freeze-thaw cycles that will disaggregate meteorites even with relatively low porosity. This device was used to disaggregate ordinary and carbonaceous chondrite regoltih breccia meteorites to search for micrometeoroid impact craters.

  13. Probing the use of spectroscopy to determine the meteoritic analogues of meteors

    Science.gov (United States)

    Drouard, A.; Vernazza, P.; Loehle, S.; Gattacceca, J.; Vaubaillon, J.; Zanda, B.; Birlan, M.; Bouley, S.; Colas, F.; Eberhart, M.; Hermann, T.; Jorda, L.; Marmo, C.; Meindl, A.; Oefele, R.; Zamkotsian, F.; Zander, F.

    2018-05-01

    Context. Determining the source regions of meteorites is one of the major goals of current research in planetary science. Whereas asteroid observations are currently unable to pinpoint the source regions of most meteorite classes, observations of meteors with camera networks and the subsequent recovery of the meteorite may help make progress on this question. The main caveat of such an approach, however, is that the recovery rate of meteorite falls is low (100) within a reasonable time frame (10-20 years), the optimal solution may be the spatial extension of existing fireball observation networks. The movie associated to this article is available at http://www.aanda.org

  14. Morphometric study of uninvolved rectal mucosa 10 cm and 20 cm away from the malignant tumor.

    Science.gov (United States)

    Despotović, Sanja Z; Milićević, Novica M; Milosević, Dragoslav P; Despotović, Nebojsa; Erceg, Predrag; Bojić, Bozidar; Bojić, Danijela; Svorcan, Petar; Mihajlović, Gordana; Dorđević, Jelena; Lalić, Ivana M; Milićević, Zivana

    2014-02-01

    Recently, many details of the interplay between tumor cells and tumor-associated stromal elements leading to the progression of malignant disease were elucidated. In contrast, little is known about the role of uninvolved stromal tissue in the remote surrounding of the malignant tumor. Therefore, we performed a computer-aided morphometric study of rectal mucosa in samples taken 10 cm and 20 cm away from the malignant tumor during endoscopic examination of 23 patients older than 60 years. The samples of rectal mucosa from 10 healthy persons of corresponding age subjected to diagnostic rectoscopy during active screening for asymptomatic cancer were used as control. All structural elements of the rectal mucosa were studied and the number of nucleated cells in the lamina propria per 0.1 mm² of tissue was assessed. Our study revealed a reduced number of cells in the lamina propria of the rectal mucosa 10 cm and 20 cm away from the tumor lesion in both male and female patients. The decreased mucosal height and increased crypt number were registered in female patients 10 cm away from the tumor. The connective tissue of lamina propria showed a disorderly organization: the collagen fibers were frail, loosely arranged and signs of tissue edema were present. Small blood vessels and capillaries were much more frequently seen than in healthy tissue. Our results demonstrate the complex interactions between the cancer and remote mucosal tissue of the affected organ.

  15. Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites

    Science.gov (United States)

    Vinogradoff, V.; Le Guillou, C.; Bernard, S.; Binet, L.; Cartigny, P.; Brearley, A. J.; Remusat, L.

    2017-09-01

    Unravelling the origin of organic compounds that were accreted into asteroids requires better constraining the impact of asteroidal hydrothermal alteration on their isotopic signatures, molecular structures, and spatial distribution. Here, we conducted a multi-scale/multi-technique comparative study of the organic matter (OM) from two CM chondrites (that originate from the same parent body or from identical parent bodies that accreted the same mixture of precursors) and underwent a different degree of hydrothermal alteration: Paris (a weakly altered CM chondrite - CM 2.8) and Murchison (a more altered one - CM 2.5). The Paris insoluble organic matter (IOM) shows a higher aliphatic/aromatic carbon ratio, a higher radical abundance and a lower oxygen content than the Murchison IOM. Analysis of the OM in situ shows that two texturally distinct populations of organic compounds are present within the Paris matrix: sub-micrometric individual OM particles and diffuse OM finely distributed within phyllosilicates and amorphous silicates. These results indicate that hydrothermal alteration on the CM parent body induced aromatization and oxidation of the IOM, as well as a decrease in radical and nitrogen contents. Some of these observations were also reported by studies of variably altered fragment of Tagish Lake (C2), although the hydrothermal alteration of the OM in Tagish Lake was apparently much more severe. Finally, comparison with data available in the literature suggests that the parent bodies of other chondrite petrologic groups could have accreted a mixture of organic precursors different from that accreted by the parent body of CMs.

  16. Core Problem: Does the CV Parent Body Magnetization require differentiation?

    Science.gov (United States)

    O'Brien, T.; Tarduno, J. A.; Smirnov, A. V.

    2016-12-01

    Evidence for the presence of past dynamos from magnetic studies of meteorites can provide key information on the nature and evolution of parent bodies. However, the suggestion of a past core dynamo for the CV parent body based on the study of the Allende meteorite has led to a paradox: a core dynamo requires differentiation, evidence for which is missing in the meteorite record. The key parameter used to distinguish core dynamo versus external field mechanisms is absolute field paleointensity, with high values (>>1 μT) favoring the former. Here we explore the fundamental requirements for absolute field intensity measurement in the Allende meteorite: single domain grains that are non-interacting. Magnetic hysteresis and directional data define strong magnetic interactions, negating a standard interpretation of paleointensity measurements in terms of absolute paleofield values. The Allende low field magnetic susceptibility is dominated by magnetite and FeNi grains, whereas the magnetic remanence is carried by an iron sulfide whose remanence-carrying capacity increases with laboratory cycling at constant field values, indicating reordering. The iron sulfide and FeNi grains are in close proximity, providing mineralogical context for interactions. We interpret the magnetization of Allende to record the intense early solar wind with metal-sulfide interactions amplifying the field, giving the false impression of a higher field value in some prior studies. An undifferentiated CV parent body is thus compatible with Allende's magnetization. Early solar wind magnetization should be the null hypothesis for evaluating the source of magnetization for chondrites and other meteorites.

  17. The Insoluble Carbonaceous Material of CM Chondrites as Possible Source of Discrete Organics During the Asteroidal Aqueous Phase

    Science.gov (United States)

    Yabuta, H.; Williams, L.; Cody, G.; Pizzarello, S.

    2005-01-01

    The larger portion of the organic carbon in carbonaceous chondrites (CC) is present as a complex and heterogeneous macromolecular material that is insoluble in acids and most solvents (IOM). So far, it has been analyzed only as a whole by microscopy (TEM) and spectroscopy (IR, NMR, EPR), which have offered and overview of its chemical nature, bonding, and functional group composition. Chemical or pyrolytic decomposition has also been used in combination with GC-MS to identify individual compounds released by these processes. Their value in the recognition of the original IOM structure resides in the ability to properly interpret the decomposition pathways for any given process. We report here a preliminary study of IOM from the Murray meteorite that combines both the analytical approaches described above, under conditions that would realistically model the IOM hydrothermal exposure in the meteorite parent body. The aim is to document the possible release of water and solvent soluble organics, determine possible changes in NMR spectral features, and ascertain, by extension, the effect of this loss on the frame of the IOM residue. Additional information is included in the original extended abstract.

  18. A sub-cm micromachined electron microscope

    Science.gov (United States)

    Feinerman, A. D.; Crewe, D. A.; Perng, D. C.; Shoaf, S. E.; Crewe, A. V.

    1993-01-01

    A new approach for fabricating macroscopic (approximately 10x10x10 mm(exp 3)) structures with micron accuracy has been developed. This approach combines the precision of semiconductor processing and fiber optic technologies. A (100) silicon wafer is anisotropically etched to create four orthogonal v-grooves and an aperture on each 10x12 mm die. Precision 308 micron optical fibers are sandwiched between the die to align the v-grooves. The fiber is then anodically bonded to the die above and below it. This procedure is repeated to create thick structures and a stack of 5 or 6 die will be used to create a miniature scanning electron microscope (MSEM). Two die in the structure will have a segmented electrode to deflect the beam and correct for astigmatism. The entire structure is UHV compatible. The performance of an SEM improves as its length is reduced and a sub-cm 2 keV MSEM with a field emission source should have approximately 1 nm resolution. A low voltage high resolution MSEM would be useful for the examination of biological specimens and semiconductors with a minimum of damage. The first MSEM will be tested with existing 6 micron thermionic sources. In the future a micromachined field emission source will be used. The stacking technology presented in this paper can produce an array of MSEMs 1 to 30 mm in length with a 1 mm or larger period. A key question being addressed by this research is the optimum size for a low voltage MSEM which will be determined by the required spatial resolution, field of view, and working distance.

  19. Determination of Am-241, Cm-242 and Cm-244 in environmental samples

    International Nuclear Information System (INIS)

    Afsar, M.; Schuettelkopf, H.

    1988-01-01

    An analytical procedure for the determination of Am and Cm in environmental, liquid and gaseous effluent samples was developed. It is based on extraction chromatography with subsequent anion and cation exchange to remove matrix elements and to purify Am and Cm, which are then electrode posited from an oxalate/HCl medium. The mean value of the chemical yield is about 90%. A detection limit of 7 μBq/g is achieved. The decontamination factors for important α emitters are > 10 4 . Four analyses/week can be performed by one technician. (orig./RB) [de

  20. Detection and rapid recovery of the Sutter's Mill meteorite fall as a model for future recoveries worldwide

    Science.gov (United States)

    Fries, Marc; Le Corre, Lucille; Hankey, Mike; Fries, Jeff; Matson, Robert; Schaefer, Jake; Reddy, Vishnu

    2014-11-01

    The Sutter's Mill C-type meteorite fall occurred on 22 April 2012 in and around the town of Coloma, California. The exact location of the meteorite fall was determined within hours of the event using a combination of eyewitness reports, weather radar imagery, and seismometry data. Recovery of the first meteorites occurred within 2 days and continued for months afterward. The recovery effort included local citizens, scientists, and meteorite hunters, and featured coordination efforts by local scientific institutions. Scientific analysis of the collected meteorites revealed characteristics that were available for study only because the rapid collection of samples had minimized terrestrial contamination/alteration. This combination of factors—rapid and accurate location of the event, participation in the meteorite search by the public, and coordinated scientific investigation of recovered samples—is a model that was widely beneficial and should be emulated in future meteorite falls. The tools necessary to recreate the Sutter's Mill recovery are available, but are currently underutilized in much of the world. Weather radar networks, scientific institutions with interest in meteoritics, and the interested public are available globally. Therefore, it is possible to repeat the Sutter's Mill recovery model for future meteorite falls around the world, each for relatively little cost with a dedicated researcher. Doing so will significantly increase the number of fresh meteorite falls available for study, provide meteorite material that can serve as the nuclei of new meteorite collections, and will improve the public visibility of meteoritics research.

  1. Studying Antarctic Ordinary Chondrite (OC) and Miller Range (MIL) Nakhlite Meteorites to Assess Carbonate Formation on Earth and Mars

    Science.gov (United States)

    Evans, Michael Ellis

    Carbonates are found in meteorites collected from Antarctica. The stable isotope composition of these carbonates records their formation environment on either Earth or Mars. The first research objective of this dissertation is to characterize the delta18O and delta 13C values of terrestrial carbonates formed on Ordinary Chondrites (OCs) collected in regions near known martian meteorites. The second objective is to characterize the delta18O and delta13C values of martian carbonates from Nakhlites collected from the Miller Range (MIL). The third objective is to assess environmental changes on Mars since the Noachian period. The OCs selected had no pre-terrestrial carbonates so any carbonates detected are presumed terrestrial in origin. The study methodology is stepped extraction of CO2 created from phosphoric acid reaction with meteorite carbonate. Stable isotope results show that two distinct terrestrial carbonate species (Ca-rich and Fe/Mg-rich) formed in Antarctica on OCs from a thin-film of meltwater containing dissolved CO2. Carbon isotope data suggests the terrestrial carbonates formed in equilibrium with atmospheric CO2 delta 13C = -7.5‰ at >15°C. The wide variation in delta 18O suggests the carbonates did not form in equilibrium with meteoric water alone, but possibly formed from an exchange of oxygen isotopes in both water and dissolved CO2. Antarctica provides a model for carbonate formation in a low water/rock ratio, near 0°C environment like modern Mars. Nakhlite parent basalt formed on Mars 1.3 billion years ago and the meteorites were ejected by a single impact approximately 11 million years ago. They traveled thru space before eventually falling to the Earth surface 10,000-40,000 years ago. Nakhlite samples for this research were all collected from the Miller Range (MIL) in Antarctica. The Nakhlite stable isotope results show two carbonate species (Ca-rich and Fe/Mg-rich) with a range of delta18O values that are similar to the terrestrial OC

  2. The role of sulfides in the fractionation of highly siderophile and chalcophile elements during the formation of martian shergottite meteorites

    Science.gov (United States)

    Baumgartner, Raphael J.; Fiorentini, Marco L.; Lorand, Jean-Pierre; Baratoux, David; Zaccarini, Federica; Ferrière, Ludovic; Prašek, Marko K.; Sener, Kerim

    2017-08-01

    The shergottite meteorites are ultramafic to mafic igneous rocks whose parental magmas formed from partial melting of the martian mantle. This study reports in-situ laser ablation inductively coupled plasma mass spectrometry analyses for siderophile and chalcophile major and trace elements (i.e., Co, Ni, Cu, As, Se, Ag, Sb, Te, Pb, Bi, and the highly siderophile platinum-group elements, PGE: Os, Ir, Ru, Rh, Pt and Pd) of magmatic Fe-Ni-Cu sulfide assemblages from four shergottite meteorites. They include three geochemically similar incompatible trace element- (ITE-) depleted olivine-phyric shergottites (Yamato-980459, Dar al Gani 476 and Dhofar 019) that presumably formed from similar mantle and magma sources, and one distinctively ITE-enriched basaltic shergottite (Zagami). The sulfides in the shergottites have been variably modified by alteration on Earth and Mars, as well as by impact shock-shock related melting/volatilization during meteorite ejection. However, they inherit and retain their magmatic PGE signatures. The CI chondrite-normalized PGE concentration patterns of sulfides reproduce the whole-rock signatures determined in previous studies. These similarities indicate that sulfides exerted a major control on the PGE during shergottite petrogenesis. However, depletions of Pt (and Ir) in sulfide relative to the other PGE suggest that additional phases such discrete Pt-Fe-Ir alloys have played an important role in the concentration of these elements. These alloys are expected to have enhanced stability in reduced and FeO-rich shergottite magmas, and could be a common feature in martian igneous systems. A Pt-rich PGM was found to occur in a sulfide assemblage in Dhofar 019. However, its origin may be related to impact shock-related sulfide melting and volatilisation during meteorite ejection. In the ITE-depleted olivine-phyric shergottites, positive relationships exist between petrogenetic indicators (e.g., whole-rock Mg-number) and most moderately to

  3. 77 FR 8877 - ICD-9-CM Coordination and Maintenance (C&M) Committee Meeting

    Science.gov (United States)

    2012-02-15

    ...), Classifications and Public Health Data Standards Staff, announces the following meeting. Name: ICD-9-CM... proposed modifications to the International Classification of Diseases, Ninth-Revision, Clinical... Infusion of Glucarpidase ICD-10 Updates: ICD-10 MS-DRG Update ICD-10 HAC Translation List Impact of ICD-10...

  4. Oral histories in meteoritics and planetary science—XXV: Vagn F. Buchwald

    Science.gov (United States)

    Sears, Derek W. G.

    2014-07-01

    Vagn Buchwald (Fig. 1) was born in Copenhagen where he attended school and college. Then after 18 months of military service, he assumed a position at the Technical University of Copenhagen. A few years later, he was presented with a piece of the Cape York meteorite, which led to an interest in iron meteorites. Through a campaign of informed searching, Vagn found the 20 ton Agpalilik meteorite (part of the Cape York shower) on 31st July 1963 and by September 1967 had arranged its transport to Copenhagen. After sorting and describing the Danish collection, which included application of the Fe-Ni-P phase diagram to iron meteorite mineralogy, Vagn was invited to sort and describe other iron meteorite collections. This led to a 7 yr project to write his monumental Handbook of Iron Meteorites. Vagn spent 3 yr in the United States and visited most of the world's museums, the visit to Berlin being especially important since the war had left their iron meteorites in bad condition and without labels. During a further decade or more of iron meteorite research, he documented natural and anthropomorphic alterations experienced by iron meteorites, discovered five new minerals (roaldite, carlsbergite, akaganeite, hibbingite, and arupite); had a mineral (buchwaldite, NaCaPO4) and asteroid (3209 Buchwald 1982 BL1) named after him; and led expeditions to Chile, Namibia, and South Africa in search of iron meteorites and information on them. Vagn then turned his attention to archeological metal artifacts. This work resulted in many papers and culminated in two major books on the subject published in 2005 and 2008, after his retirement in 1998. Vagn Buchwald has received numerous Scandinavian awards and honors, and served as president of the Meteoritical Society in 1981-1982.

  5. Micro-mapping Meteorite Surfaces on Mars using Microscopic Imager Mosaics — A Tool for Unraveling Weathering History at Meridiani Planum

    Science.gov (United States)

    Ashley, J. W.; Herkenhoff, K. E.; Golombek, M. P.; Johnson, J. R.

    2012-12-01

    Meteorites found on Mars provide valuable insights into martian surface processes. During the course of Mars Exploration Rover (MER) extended missions, Spirit and Opportunity have identified 17 confirmed and candidate meteorites on Mars, most of which are irons. The iron meteorites exhibit morphologies and coatings that communicate complex post-fall exposure histories relevant to an understanding of climate near the martian equator [1-4]. Both chemical and mechanical weathering effects are represented. Among the more significant of these are: 1) cm-scale hollowing, 2) surficial rounding, 3) mass excavation/dissolution and removal, 4) differential etching of kamacite plates and taenite lamellae, revealing Widmanstätten patterns, 5) discontinuous iron oxide coatings, and 6) the effects of cavernous weathering, which often penetrate to rock interiors. Determining the nature, magnitude, and timing of each process and its associated features is a complex problem that will be aided by laboratory experiments, image processing, and careful surface evaluation. Because some features appear to superpose others in ways analogous to stratigraphic relationships, Microscopic Imager (MI) mosaics are useful for sketching "geologic maps" of meteorite surfaces. Employing the techniques of conventional planetary mapping [5], each map was drafted manually using full-resolution MI mosaics and Adobe Photoshop software. Units were selected to represent the oxide coating, dust-coated surfaces, sand-coated surfaces, taenite lamellae, and uncoated metal. Also included are areas in shadow, and regions of blooming caused by specular reflection of metal. Regmaglypt rim crests are presented as lineations. As with stratigraphic relationships, noting embayments and other cross-cutting relationships assists with establishing the relative timing for observed weathering effects. In addition to suggesting alternating sequences of wind and water exposure [1], patterns in oxide coating occurrence show

  6. Accuracy of free energies of hydration using CM1 and CM3 atomic charges.

    Science.gov (United States)

    Udier-Blagović, Marina; Morales De Tirado, Patricia; Pearlman, Shoshannah A; Jorgensen, William L

    2004-08-01

    Absolute free energies of hydration (DeltaGhyd) have been computed for 25 diverse organic molecules using partial atomic charges derived from AM1 and PM3 wave functions via the CM1 and CM3 procedures of Cramer, Truhlar, and coworkers. Comparisons are made with results using charges fit to the electrostatic potential surface (EPS) from ab initio 6-31G* wave functions and from the OPLS-AA force field. OPLS Lennard-Jones parameters for the organic molecules were used together with the TIP4P water model in Monte Carlo simulations with free energy perturbation theory. Absolute free energies of hydration were computed for OPLS united-atom and all-atom methane by annihilating the solutes in water and in the gas phase, and absolute DeltaGhyd values for all other molecules were computed via transformation to one of these references. Optimal charge scaling factors were determined by minimizing the unsigned average error between experimental and calculated hydration free energies. The PM3-based charge models do not lead to lower average errors than obtained with the EPS charges for the subset of 13 molecules in the original study. However, improvement is obtained by scaling the CM1A partial charges by 1.14 and the CM3A charges by 1.15, which leads to average errors of 1.0 and 1.1 kcal/mol for the full set of 25 molecules. The scaled CM1A charges also yield the best results for the hydration of amides including the E/Z free-energy difference for N-methylacetamide in water. Copyright 2004 Wiley Periodicals, Inc.

  7. A Stranger in the Midst: Searching for Relict Grains from Rare Meteorite Types in Mid-Ordovician Limestone Strata

    Science.gov (United States)

    Martin, E.; Schmitz, B.

    2016-08-01

    A layer of Mid-Ordovician limestone harbors exceptional amounts of L-chondritic chromite grains. The layer also contains grains from potentially rarer types of meteorites, following the discovery of the fossil meteorite Österplana 065.

  8. Lunar and Meteorite Sample Education Disk Program — Space Rocks for Classrooms, Museums, Science Centers, and Libraries

    Science.gov (United States)

    Allen, J.; Luckey, M.; McInturff, B.; Huynh, P.; Tobola, K.; Loftin, L.

    2010-03-01

    NASA’s Lunar and Meteorite Sample Education Disk Program has Lucite disks containing Apollo lunar samples and meteorite samples that are available for trained educators to borrow for use in classrooms, museums, science center, and libraries.

  9. The Rosetta Stones of Mars — Should Meteorites be Considered as Samples of Opportunity for Mars Sample Return?

    Science.gov (United States)

    Tait, A. W.; Schröder, C.; Ashley, J. W.; Velbel, M. A.; Boston, P. J.; Carrier, B. L.; Cohen, B. A.; Bland, P. A.

    2018-04-01

    We summarize insights about Mars gained from investigating meteorites found on Mars. Certain types of meteorites can be considered standard probes inserted into the martian environment. Should they be considered for Mars Sample Return?

  10. The Meteoritical Quincentennial: The Stone of Ensisheim 1492-1992

    Science.gov (United States)

    Marvin, U. B.

    1992-07-01

    This year marks the 500th anniversary of the fall of a meteorite at Ensisheim in Alsace. In at least two respects this event is unique in the history of meteoritics. First, this was the earliest witnessed meteorite fall in the West from which pieces are preserved. Second, it is the only meteorite of which a continuous five-century public record exists in manuscripts and books. Beginning with newsheets printed in 1492, writings about this event illuminate the evolution of ideas from a 15th century belief that stones from the sky were of miraculous origin, to an 18th century conviction that stones do not fall from the sky, to our present view that they fall in abundance, originating in interplanetary space (Marvin, 1992). This paper will highlight certain previously unexamined aspects of the story and address problems inherent in historical analysis. Unusable Maps. The fall of the stone was heralded by an explosion which, according to Sebastian Brant (1492), was heard along the valleys of the Danube, Neckar, Aare, Ill, and Rhine and in the alpine cantons of Schwyz and Uri. Contemporary maps, such as that published in The Nuremberg Chronicle of 1493, so distorted the regional geography that a fireball trajectory cannot be reconstructed on them. On modern maps, however, the areas Brant listed stretch about 150 km to the southeast of Ensisheim, a distance well within the range of sounds reported from other exploding fireballs. Newton (1891) and Marvin (1992) worked out possible trajectories that could account for the sound being heard in all named localities. This suggests that, far from exaggerating distances for dramatic effect, Brant's description may well have been accurate. If so, he compiled his information from word-of-mouth reports without reference to the rudimentary maps available in his time. The Language of Wonder. A document mounted beside the stone in the Ensisheim church stated that learned men did not know what it was: it must be supernatural, a wonder

  11. Case study of chondrule alteration with IR spectroscopy in NWA 2086 CV3 meteorite

    Science.gov (United States)

    Kereszturi, A.; Gyollai, I.; Szabó, M.

    2015-02-01

    Analyzing the alteration in an olivine chondrule of the NWA 2086 CV3 meteorite, infrared spectral, electron microprobe and optical microscopic observations were correlated to each other. The intensity and wavelength positions of olivine peaks changed characteristically with the progression of alteration and related Fe/Mg substitution inward of the chondrule. Moderate to good correlations were identified between Fo% composition and positions of 830 and 860 cm-1 IR peaks. The disappearance of 1020 cm-1 peak by structural change happens already at a low level alteration without changing the optical appearance of the mineral. The existence of the 980 cm-1 peak is found to be an indicator of the intact phase of olivine. While profiles perpendicular to the chondrule's perimeter showed that the alteration progressed 15-20 μm distance inward without observable fractures (probablly by some diffusion related process), the "alteration distance" from various obvious fractures inside the chondrule was only 3-5 μm distance. These observations suggest that the substitution was more effective close to the matrix, and also related to some fluids that although were able to circulate along the large internal fractures too, did not produce such strong substitution there, like what happened close to the matrix. It was also demonstrated that the poorly exploited contact mode observations with ATR based reflection method in infrared spectroscopy provide a useful tool to analyze the alteration at micrometer scale without much sample preparation, and enable identifying alterations already at such a low level where the olivines still look optically intact.

  12. Authenticating the recovery location of meteorites: The case of Castenaso

    Science.gov (United States)

    Folco, Luigi; D'Orazio, Massimo; Perchiazzi, Natale

    2007-03-01

    This forensic work aims to authenticate the recovery location of Castenaso, a 120 g ordinary chondritic (L5) meteorite reportedly found in 2003 along the sandy bank of the Idice Stream, near the village of Castenaso (Bologna, Emilia-Romagna, Italy). Using the hypothesis that Castenaso was instead a hot-desert meteorite, we conducted a comparative mineralogical and geochemical study of major weathering effects on European and Saharan ordinary chondrites as potential markers of the environment where Castenaso resided during its terrestrial lifetime.Inductively coupled plasma-mass spectrometry (ICP-MS) data reveals that Castenaso is significantly enriched in Sr, Ba, Tl, and U, and suggests geochemical alteration in a hot-desert environment. The alteration is minor: Castenaso is not coated by desert varnish and does not show significant light rare earth element (LREE) enrichment or loss of Ni and Co.The apparent contrast in size, morphology, and composition between the soil particles filling the external fractures of Castenaso and those from the bank of the Idice Stream observed under the scanning electron microscope (SEM) suggests that Castenaso did not reside at the reported find location. Abraded quartz grains (up to 1 mm in size) in Castenaso are undoubtedly from a hot-desert eolian environment: they are well-rounded and show external surfaces characterized by the presence of dish-shaped concavities and upturned silica plates that have been subject to solution-precipitation and subsequent smoothing.We therefore conclude that Castenaso is one of the many hot-desert ordinary chondrite finds, probably from the Sahara, that is currently available on the market. This forensic work provides the scientific grounds for changing the name of this meteorite.

  13. Moessbauer studies on the paramagnetic porton of alkidirat meteorite

    International Nuclear Information System (INIS)

    Kamal, Huda Mohamed

    1995-11-01

    This work was performed on a sample from alkidirat meteorite which fell west of Sudan by means of Moessbauer effect spectrometer. results showed the absence of transition temperature from the paramagnetic state to the magnetic state in the temperature range from 300K down to 16K. Also, it was found that olivine and ortho pyroxene exist together in site M 1 , while clinothyroxene exists alone in site M 2 . Formula for the composition of ortho pyroxene in the sample were also obtained and they were in good agreement with previous studies. The disorder parameter was also calculated and it showed that the pyroxene present in the sample is well-ordered.(Author)

  14. Large meteorite impacts: The K/T model

    Science.gov (United States)

    Bohor, B. F.

    1992-01-01

    The Cretaceous/Tertiary (K/T) boundary event represents probably the largest meteorite impact known on Earth. It is the only impact event conclusively linked to a worldwide mass extinction, a reflection of its gigantic scale and global influence. Until recently, the impact crater was not definitively located and only the distal ejecta of this impact was available for study. However, detailed investigations of this ejecta's mineralogy, geochemistry, microstratigraphy, and textures have allowed its modes of ejection and dispersal to be modeled without benefit of a source crater of known size and location.

  15. The common property of isotope anomalies in meteorites

    International Nuclear Information System (INIS)

    Robert, F.

    2004-01-01

    The treatment proposed to account for the non-mass-dependent isotopic fractionation effect observed for oxygen isotopes during the synthesis of ozone (Robert and Camy-Peyret 2001) is applied to other chemical elements. A numerical treatment to calculate isotopic reaction rate ratios is proposed. This treatment yields non-mass-dependent isotopic effects in other chemical elements, qualitatively similar to those observed in some of the high temperature minerals found in the carbonaceous meteorites. This treatment may reflect the numerical consequences of an unrecognized quantum mechanical effect, linked to a property of chemical reactions involving indistinguishable isotopes. (author)

  16. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    Science.gov (United States)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  17. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    Science.gov (United States)

    Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

    1997-01-01

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  18. The Nature of C Asteroid Regolith from Meteorite Observations

    Science.gov (United States)

    Zolensky, M.; Mikouchi, T.; Hagiya, K.; Ohsumi, K.; Komatsu, M.; Jenniskens, P.; Le, L.; Yin, Q.-Z; Kebukawa, Y.; Fries, M.

    2013-01-01

    Regolith from C (and related) asteroid bodies are a focus of the current missions Dawn at Ceres, Hayabusa 2 and OSIRIS REx. An asteroid as large as Ceres is expected to be covered by a mature regolith, and as Hayabusa demonstrated, flat and therefore engineeringly-safe ponded deposits will probably be the sampling sites for both Hayabusa 2 and OSIRIS REx. Here we examine what we have learned about the mineralogy of fine-grained asteroid regolith from recent meteorite studies and the examination of the samples harvested from asteroid Itokawa by Hayabusa.

  19. Solar nebula magnetic fields recorded in the Semarkona meteorite

    DEFF Research Database (Denmark)

    Fu, Roger R.; Weiss, Benjamin P.; Lima, Eduardo A.

    2014-01-01

    on the intensity of these fields. Here we show that dusty olivine-bearing chondrules from the Semarkona meteorite were magnetized in a nebular field of 54 ± 21 microteslas. This intensity supports chondrule formation by nebular shocks or planetesimal collisions rather than by electric currents, the x......-wind, or other mechanisms near the Sun. This implies that background magnetic fields in the terrestrial planet-forming region were likely 5 to 54 microteslas, which is sufficient to account for measured rates of mass and angular momentum transport in protoplanetary disks....

  20. Determination of {sup 10}Be, {sup 26}Al, and {sup 36}Cl in meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Merchel, S.; Herpers [Koeln Univ. (Germany); Neumann, S.; Michel, R. [Hannover Univ. (Germany); Kubik, P.W.; Synal, H.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Suter, M. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Long-lived cosmogenic radionuclides were determined in stony ({sup 10}Be, {sup 26}Al) and iron ({sup 10}Be, {sup 26}Al, {sup 36}Cl) meteorites using AMS after radiochemical separation. A selection of these data is briefly discussed with respect to exposure histories of the meteorites and is compared to model calculations. (author) 2 figs., 5 refs.

  1. Meteoritic Input of Amino Acids and Nucleobases: Methodology and Implications for the Origins of Life

    Science.gov (United States)

    Burton, Aaron S.; Stern, Jennifer C.; Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-01-01

    The discoveries of amino acids of extraterrestrial origin in many meteorites over the last 40 years have revolutionized the Astrobiology field. A variety of non-terrestrial amino acids similar to those found in life on Earth have been detected in meteorites. A few amino acids have even been found with chiral excesses, suggesting that meteorites could have contributed to the origin of homochirality in life on Earth. In addition to amino acids, which have been productively studied for years, sugar-like molecules, activated phosphates, and nucleobases have also been determined to be indigenous to numerous meteorites. Because these molecules are essential for life as we know it, and meteorites have been delivering them to the Earth since accretion, it is plausible that the origin(s) of life on Earth were aided by extraterrestrially-synthesized molecules. Understanding the origins of life on Earth guides our search for life elsewhere, helping to answer the question of whether biology is unique to Earth. This tutorial review focuses on meteoritic amino acids and nucleobases, exploring modern analytical methods and possible formation mechanisms. We will also discuss the unique window that meteorites provide into the chemistry that preceded life on Earth, a chemical record we do not have access to on Earth due to geologic recycling of rocks and the pervasiveness of biology across the planet. Finally, we will address the future of meteorite research, including asteroid sample return mIssIons.

  2. Pre-Entry Size and Cosmic History of the Annama Meteorite

    Czech Academy of Sciences Publication Activity Database

    Kohout, Tomáš; Meier, M.M.M.; Maden, C.; Busemann, H.; Welten, K.C.; Laubenstein, M.; Caffee, M. W.; Gritsevich, M.; Grokhovsky, V.

    2016-01-01

    Roč. 51, SI Supplement 1 (2016), A380-A380 ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /79./. 07.08.2016-12.08.2016, Berlin] Institutional support: RVO:67985831 Keywords : noble gases * cosmogenic radionuclides chondrite * meteorite * Annama Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  3. Crystal-field spectra of fassaite from the Angra dos Reis meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Mao, H K; Bell, P M; Virgo, D [Carnegie Institution of Washington, D.C. (USA)

    1977-06-01

    Fassaitic pyroxene from the Angra dos Reis meteorite has striking spectral properties. The /sup 57/Fe Moessbauer spectra show no Fe/sup 3 +/, and thus the absorption is thought to originate from a complex charge-transfer process. Intense absorption at 480 nm dominates the spectrum of the meteorite and may be important in the interpretation of telescope spectra of objects in space.

  4. Thermal and radiation history of meteorites as revealed by their thermoluminescence records

    International Nuclear Information System (INIS)

    Bhandari, N.

    1985-01-01

    Attempts are described to derive information about important parameters of the thermal and radiation history of meteorites from a study of depth profile of thermoluminescence coupled to appropriate annealing studies. In this review some possibilities are examined, emphasizing various factors cardinal to any meaningful application of TL in meteoritics. (author)

  5. Magnetic particles extracted from manganese nodules: Suggested origin from stony and iron meteorites

    Science.gov (United States)

    Finkelman, R.B.

    1970-01-01

    On the basis of x-ray diffraction and electron microprobe data, spherical and ellipsoidal particles extracted from manganese nodules were divided into three groups. Group I particles are believed to be derived from iron meteorites, and Group II particles from stony meteorites. Group III particles are believed to be volcanic in origin.

  6. Condensation time of the solar nebula from extinct I-129 in primitive meteorites

    Science.gov (United States)

    Lewis, R. S.; Anders, E.

    1975-01-01

    Mineral separates from five carbonaceous chondrites were dated by extinct 16 million year I-129, in an attempt to establish the condensation time of the solar nebula. Two Fe3O4 or Fe3O4-FeS samples from the Murchison and Orgueil meteorites are older than any other material dated thus far, and apparently formed within 200,000 years of each other. The great age, close isochronism, and primitive nature of the samples suggest that the event recorded was the condensation stage of the solar nebula. It provides a suitable zero point for the chronology of the early solar system. The I-129/I-127 ratio during condensation of the nebula was (1.46 plus or minus 0.04) times 0.0001. The recrystallized C4 chondrite Karoonda began to retain Xe-129 1.8 plus or minus 0.5 million years after the above event. This short cooling time implies rapid accretion (not exceeding 1 million years) and a shallow origin (not exceeding 10 km) below the surface of its parent body.-

  7. Condensation time of the solar nebula from extinct 129I in primitive meteorites

    International Nuclear Information System (INIS)

    Lewis, R.S.; Anders, E.

    1975-01-01

    Mineral separates from five carbonaceous chondrites were dated by extinct 16 million year 129 I, in an attempt to establish the condensation time of the solar nebula. Two Fe 3 O 4 or Fe 3 O 4 --FeS samples from the Murchison and Orgueil meteorites are older than any other material dated thus far, and apparently formed within 2 x 10 5 years of each other. The great age, close isochronism, and primitive nature of the samples suggest that the event recorded was the condensation stage of the solar nebula. It provides a suitable zero point for the chronology of the early solar system. The 129 I/ 127 I ratio during condensation of the nebula was (1.46 +- 0.04) x 10 -4 . The recrystallized C4 chondrite Karoonda began to retain 129 Xe 1.8 +- 0.5 million years after the above event. This short cooling time implies rapid accretion (less than or equal to 1 million years) and a shallow origin (less than or equal to 10 km) below the surface of its parent body. (U.S.)

  8. Evidence for a meteoritic origin of the September 15, 2007, Carancas crater

    Science.gov (United States)

    Le Pichon, A.; Antier, K.; Cansi, Y.; Hernandez, B.; Minaya, E.; Burgoa, B.; Drob, D.; Evers, L. G.; Vaubaillon, J.

    2008-11-01

    On September 15th, 2007, around 11:45 local time in Peru, near the Bolivian border, the atmospheric entry of a meteoroid produced bright lights in the sky and intense detonations. Soon after, a crater was discovered south of Lake Titicaca. These events have been detected by the Bolivian seismic network and two infrasound arrays operating for the Comprehensive Nuclear-Test-Ban Treaty Organization, situated at about 80 and 1620 km from the crater. The localization and origin time computed with the seismic records are consistent with the reported impact. The entry elevation and azimuthal angles of the trajectory are estimated from the observed signal time sequences and back-azimuths. From the crater diameter and the airwave amplitudes, the kinetic energy, mass and explosive energy are calculated. Using the estimated velocity of the meteoroid and similarity criteria between orbital elements, an association with possible parent asteroids is attempted. The favorable setting of this event provides a unique opportunity to evaluate physical and kinematic parameters of the object that generated the first actual terrestrial meteorite impact seismically recorded.

  9. Meteorite Falls Observed in U.S. Weather Radar Data in 2015 and 2016 (To Date)

    Science.gov (United States)

    Fries, Marc; Fries, Jeffrey; Hankey, Mike; Matson, Robert

    2016-01-01

    To date, over twenty meteorite falls have been located in the weather radar imagery of the National Oceanic and Atmospheric Administration (NOAA)'s NEXRAD radar network. We present here the most prominent events recorded since the last Meteoritical Society meeting, covering most of 2015 and early 2016. Meteorite Falls: The following events produced evidence of falling meteorites in radar imagery and resulted in meteorites recovered at the fall site. Creston, CA (24 Oct 2015 0531 UTC): This event generated 218 eyewitness reports submitted to the American Meteor Society (AMS) and is recorded as event #2635 for 2015 on the AMS website. Witnesses reported a bright fireball with fragmentation terminating near the city of Creston, CA, north of Los Angeles. Sonic booms and electrophonic noise were reported in the vicinity of the event. Weather radar imagery records signatures consistent with falling meteorites in data from the KMUX, KVTX, KHNX and KVBX. The Meteoritical Society records the Creston fall as an L6 meteorite with a total recovered mass of 688g. Osceola, FL (24 Jan 2016 1527 UTC): This daytime fireball generated 134 eyewitness reports on AMS report number 266 for 2016, with one credible sonic boom report. The fireball traveled roughly NE to SW with a terminus location north of Lake City, FL in sparsely populated, forested countryside. Radar imagery shows distinct and prominent evidence of a significant meteorite fall with radar signatures seen in data from the KJAX and KVAX radars. Searchers at the fall site found that recoveries were restricted to road sites by the difficult terrain, and yet several meteorites were recovered. Evidence indicates that this was a relatively large meteorite fall where most of the meteorites are unrecoverable due to terrain. Osceola is an L6 meteorite with 991 g total mass recovered to date. Mount Blanco, TX (18 Feb 2016 0343 UTC): This event produced only 39 eyewitness reports and is recorded as AMS event #635 for 2016. No

  10. Do the age differences given by relative or absolute chronologies of the most ancient meteorites correspond to real age differences

    International Nuclear Information System (INIS)

    Pellas, P.

    1982-01-01

    Recent results from absolute and relative chronologies of the most ancient meteorites are reviewed in order to analyze if they are significant or not. Use of the various chronometers to analyze the same meteoritic sample is shown to be an interesting approach to retrace the prehistory of meteorites and their environments. (orig.)

  11. The Enantiomeric Ratios of Meteoritic Organic Compounds: Their Possible Roles in the Origin of Life

    Science.gov (United States)

    Cooper, George

    2012-01-01

    This talk will give an overview of the enantiomer (mirror-image) ratios of organic compounds in meteorites and also describe the results of the present work in my lab. The primary focus will be on sugar derivatives (sugar acids) of carbonaceous meteorites. Our work begins to address questions associated with chirality, i.e., the origins of homochirality. On Earth, biological monomers (amino acids, sugars, etc.) are usually found with one of the enantiomers more abundant than the other. However, biological polymers (proteins, nucleic acids, etc.) are only composed of one enantiomer i.e., they are homochiral. There are hints in meteorites that some organic molecules may also exist in homochiral forms. The talk will address questions such as: did extraterrestrial sources aid in the beginning of this homochirality? Do the increasing size and apparent enantiomer excesses of some meteoritic compounds also extend to larger meteoritic compounds and polymers?

  12. Parenting Perfectionism and Parental Adjustment

    OpenAIRE

    Lee, Meghan A.; Schoppe-Sullivan, Sarah J.; Kamp Dush, Claire M.

    2012-01-01

    The parental role is expected to be one of the most gratifying and rewarding roles in life. As expectations of parenting become ever higher, the implications of parenting perfectionism for parental adjustment warrant investigation. Using longitudinal data from 182 couples, this study examined the associations between societal- and self-oriented parenting perfectionism and new mothers’ and fathers’ parenting self-efficacy, stress, and satisfaction. For mothers, societal-oriented parenting perf...

  13. MULTIPLE ORIGINS OF NITROGEN ISOTOPIC ANOMALIES IN METEORITES AND COMETS

    International Nuclear Information System (INIS)

    Aleon, Jerome

    2010-01-01

    Isotopic fractionation and mixing calculations compared with coupled hydrogen and nitrogen isotopic composition of organic molecules from primitive chondrites, interplanetary dust particles (IDPs), and comets C/1995 O1 (Hale-Bopp) and 81P/Wild2 reveal that meteoritic and cometary organic matter contains three different isotopic components of different origins. (1) A major component of carbonaceous chondrites, IDPs, and comets Hale-Bopp and Wild2 shows correlated H and N isotopic compositions attributable to isotope exchange between an organic matter of solar composition and a reservoir formed by ion-molecule reactions at T 15 N-rich component having identical 15 N and D enrichments relative to the protosolar gas. Temperatures > 100 K deduced from the low D/H ratio and an anti-correlation between the abundance of this component and meteoritic age indicate a late origin in the solar protoplanetary disk. N 2 self-shielding and the non-thermal nucleosynthesis of 15 N upon irradiation are possible but unlikely sources of this component, and a chemical origin is preferred. (3) An interstellar component with highly fractionated hydrogen isotopes and unfractionated nitrogen isotopes is present in ordinary chondrites. A dominantly solar origin of D and 15 N excesses in primitive solar system bodies shows that isotopic anomalies do not necessarily fingerprint an interstellar origin and implies that only a very small fraction of volatile interstellar matter survived the events of solar system formation.

  14. Structural Characterization of Iron Meteorites through Neutron Tomography

    Directory of Open Access Journals (Sweden)

    Stefano Caporali

    2016-02-01

    Full Text Available In this communication, we demonstrate the use of neutron tomography for the structural characterization of iron meteorites. These materials prevalently consist of metallic iron with variable nickel content. Their study and classification is traditionally based on chemical and structural analysis. The latter requires cutting, polishing and chemical etching of large slabs of the sample in order to determine the average width of the largest kamacite lamellae. Although this approach is useful to infer the genetical history of these meteorites, it is not applicable to small or precious samples. On the base of different attenuation coefficient of cold neutrons for nickel and iron, neutron tomography allows the reconstruction of the Ni-rich (taenite and Ni-poor (kamacite metallic phases. Therefore, the measure of the average width of the largest kamacite lamellae could be determined in a non-destructive way. Furthermore, the size, shape, and spatial correlation between kamacite and taenite crystals were obtained more efficiently and accurately than via metallographic investigation.

  15. Meteor Crater (Barringer Meteorite Crater), Arizona: Summary of Impact Conditions

    Science.gov (United States)

    Roddy, D. J.; Shoemaker, E. M.

    1995-09-01

    Meteor Crater in northern Arizona represents the most abundant type of impact feature in our Solar System, i.e., the simple bowl-shaped crater. Excellent exposures and preservation of this large crater and its ejecta blanket have made it a critical data set in both terrestrial and planetary cratering research. Recognition of the value of the crater was initiated in the early 1900's by Daniel Moreau Barringer, whose 27 years of exploration championed its impact origin [1]. In 1960, Shoemaker presented information that conclusively demonstrated that Meteor Crater was formed by hypervelocity impact [2]. This led the U.S. Geological Survey to use the crater extensively in the 1960-70's as a prime training site for the Apollo astronauts. Today, Meteor Crater continues to serve as an important research site for the international science community, as well as an educational site for over 300,000 visitors per year. Since the late 1950's, studies of this crater have presented an increasingly clearer view of this impact and its effects and have provided an improved view of impact cratering in general. To expand on this data set, we are preparing an upgraded summary on the Meteor Crater event following the format in [3], including information and interpretations on: 1) Inferred origin and age of the impacting body, 2) Inferred ablation and deceleration history in Earth's atmosphere, 3) Estimated speed, trajectory, angle of impact, and bow shock conditions, 4) Estimated coherence, density, size, and mass of impacting body, 5) Composition of impacting body (Canyon Diablo meteorite), 6) Estimated kinetic energy coupled to target rocks and atmosphere, 7) Terrain conditions at time of impact and age of impact, 8) Estimated impact dynamics, such as pressures in air, meteorite, and rocks, 9) Inferred and estimated material partitioning into vapor, melt, and fragments, 10) Crater and near-field ejecta parameters, 11) Rock unit distributions in ejecta blanket, 12) Estimated far

  16. Investigations of Al-Dalang and Al-Hawashat meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, A. M., E-mail: abbasher@squ.edu.om [Sultan Qaboos University, College of Science (Oman); Abdallah, S. B. [University of Khartoum, Department of Geology, Faculty of Science (Sudan); Al-Rawas, A. D.; Al-Mabsali, F. N.; Widatallah, H. M.; Elzain, M. E.; Yousif, A. A. [Sultan Qaboos University, College of Science (Oman); Ericsson, T. [Uppsala University, Department of Physics and Material Sciences (Sweden); Annersten, H. [Uppsala University, Department of Earth Sciences (Sweden)

    2016-12-15

    Mössbauer spectroscopy, X-ray diffraction (XRD) measurements, and electron microprobe analysis (EMPA) have been performed on two meteorites named Al-Dalang and Al-Hawashat after identifying their falling sites in the Western region of Sudan. These two meteorites are ordinary chondrites with similar mineralogy. XRD and EMPA show that the two specimens consist of primary olivine, ortho-pyroxene and later crystallising clino-pyroxene as reaction rims against plagioclase. Fe-metal phases are dominated by kamacite (≈6 wt.% Ni) and minor amounts of tetrataenite (≈52 wt.% Ni). Troilite (FeS) and alabandite (MnS) are optically observed as sulphide phases. The Mössbauer measurements at 295 and 78 K are in agreement with the above characterizations, showing at least two paramagnetic doublets which are assigned to olivine and pyroxene and magnetic sextets assigned to kamacite (hyperfine field ≈33.5 T) and troilite FeS (hyperfine field ≈31 T).

  17. Trace Element Geochemistry of Martian Iddingsite in the Lafayette Meteorite

    Science.gov (United States)

    Treiman, Allan H.; Lindstrom, David J.

    1997-01-01

    The Lafayette meteorite contains abundant iddingsite, a fine-grained intergrowth of smectite clay, ferrihydrite, and ionic salt minerals. Both the meteorite and iddingsite formed on Mars. Samples of iddingsite, olivine, and augite pyroxene were extracted from Lafayette and analyzed for trace elements by instrumental neutron activation. Our results are comparable to independent analyses by electron and ion microbeam methods. Abundances of most elements in the iddingsite do not covary significantly. The iddingsite is extremely rich in Hg, which is probably terrestrial contamination. For the elements Si, Al, Fe, Mn, Ni, Co, and Zn, the composition of the iddingsite is close to a mixture of approximately 50% Lafayette olivine + approximately 40% Lafayette siliceous glass + approximately 1O% water. Concordant behavior among these elements is not compatible with element fractionations between smectite and water, but the hydrous nature and petrographic setting of the iddingsite clearly suggest an aqueous origin. These inferences are both consistent, however, with deposition of the iddingsite originally as a silicate gel, which then crystallized (neoformed) nearly isochemically. The iddingsite contains significantly more magnesium than implied by the model, which may suggest that the altering solutions were rich in Mg(2+).

  18. A "Mesosiderite" Rock from Northern Siberia, Russia: Not a Meteorite

    Science.gov (United States)

    Treiman, Allan H.; Lindstrom, David J.; Schwandt, Craig S.; Franchi, Ian A.; Morgan, Matthew L.

    2002-01-01

    A possible mesosiderite meteorite was found in the area of the Putorana Plateau, Noril'sk district, Siberia, Russia. Although this rock resembles a mesosiderite in its hand-sample aspect and in having Ni-bearing iron metal, it is not a meteorite. This inference is based on the lack of a fusion crust, the lack of cosmogenic nuclides, oxygen with terrestrial isotope ratios, and several mineral chemical criteria. Most likely, the rock is from the iron-metal-bearing basalts of the Siberian Trap basalt sequence, which are mined for their base and platinum-group metals. Mesosiderite imposters like this may be recognized by: (1) the presence of Cu metal in hand sample or as microscopic blebs in the low-Ni metal (kamacite), (2) the absence of high-Ni metal (taenite), and (3) the presence of iron carbide (cohenite) enclosing the kamacite. Even if these macroscopic tests are inconclusive, isotopic and mineral chemical tests will also distinguish rocks like this from mesosiderites.

  19. Remote TL and OSL for asteroid and meteorite study

    International Nuclear Information System (INIS)

    Takaki, Shunji; Ikeya, Motoji; Yamanaka, Chihiro

    1997-01-01

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) of the Allende meteorite have been studied using infrared CO 2 laser light as a heat source and He-Ne laser light to excite the material, respectively from a long distance. New techniques of remote TL (R-TL) and remote OSL (R-OSL) have been developed for future remote dating from a long distance in a planetary survey. The upper limits of the distance for R-TL and R-OSL were estimated using the laboratory TL signal of the meteorite peaking at 320 o C: about 400 photons s -1 for the R-TL and 60 photons s -1 for R-OSL at a distance of 1 km using a laser beam with the divergence of 0.1 mrad at powers of 100 and 1 W, respectively. An age limit of 10 5 or 10 6 years due to the signal saturation and the objects heterogeneity, as expected from previous studies, may make the asteroid survey difficult but would still help to investigate the surface activities of icy planets and satellites in outer planet worlds. (author)

  20. Mineralogical characterization of a meteorite impact in Carancas, Puno

    International Nuclear Information System (INIS)

    Ceron Loayza, Maria L.; Bravo Cabrejos, Jorge A.

    2009-01-01

    We report the results of the study of a meteorite that impacted an inhabited zone in the neighborhood of the town of Carancas, Puno Region, about 1,300 km south of Lima. The analysis carried out by X ray diffractometry, transmission Moessbauer spectroscopy (at room temperature and at 4,2 K), and by energy dispersive X ray fluorescence reveal the presence in the meteorite simple of magnetic sites assigned to the Fe-Ni and troilite (Fe,S) phases, and of 3 paramagnetic doublets, two of them assigned to Fe 2+ , one associated to olivine and the other to pyroxene, and the third one due to a site occupied by Fe 3+ , which can be associated to oxides in a superparamagnetic state and/or by an Fe hydroxide. The soil samples from the crater reveal a composition that consists mainly of quartz, albite and impactites such as coesite and stishovite (SiO 2 ). The occurrence of these phases with a high content of SiO 2 in the crater soils strengthens the hypothesis of their origin induced by impact; we observe also the presence of the Fe oxide hematite, of aluminum silicates such as illite and montmorillonite, and an unassigned phase of Fe 3+ . In general, the results obtained by these techniques complement each other rather well and allow the verification of the origin of the studied simples. (author).

  1. On the Maillard reaction of meteoritic amino acids

    Science.gov (United States)

    Kolb, Vera M.; Bajagic, Milica; Liesch, Patrick J.; Philip, Ajish; Cody, George D.

    2006-08-01

    We have performed the Maillard reaction of a series of meteoritic amino acids with sugar ribose under simulated prebiotic conditions, in the solid state at 65°C and at the room temperature. Many meteoritic amino acids are highly reactive with ribose, even at the room temperature. We have isolated high molecular weight products that are insoluble in water, and have studied their structure by the IR (infrared) and solid-state C-13 NMR (nuclear magnetic resonance) spectroscopic methods. The functional groups and their distribution were similar among these products, and were comparable to the previously isolated insoluble organic materials from the Maillard reaction of the common amino acids with ribose. In addition, there were some similarities with the insoluble organic material that is found on Murchison. Our results suggest that the Maillard products may contribute to the composition of the part of the insoluble organic material that is found on Murchison. We have also studied the reaction of sodium silicate solution with the Maillard mixtures, to elucidate the process by which the organic compounds are preserved under prebiotic conditions.

  2. Laboratory simulation of meteoritic noble gases. 2. Sorption of xenon on carbon: etching and heating experiments

    Energy Technology Data Exchange (ETDEWEB)

    Zadnik, M.G.; Wacker, J.F.; Lewis, R.S. (Chicago Univ., IL (USA). Enrico Fermi Inst.)

    1985-04-01

    Sixteen amorphous carbon (lampblack) samples that had been exposed to Xe/sup 127/ and pumped for > 9 hrs to remove the most labile gas were examined by etching with HNO/sub 3/, for comparison with the release pattern of meteoritic xenon. Samples originally exposed at 100 to 200 deg C lost 90% of their Xe very readily, when the surface had been etched to a mean depth of only approx. 0.2 A. This suggests that the Xe is adsorbed mainly at rare sites that are unusually reactive to HNO/sub 3/. The adsorbed Xe survived several months' storage in vacuum, but on exposure to air, part of it was lost within a few hours, while the remainder persisted without measurable exchange. Samples exposed at 800 to 1000 deg C had a similar adsorbed component, as well as a second, tightly bound component extending to a mean depth of up to 30 A; this component had apparently diffused into the carbon during exposure. The (microscopic) diffusion coefficient for graphitic crystallites is 5 x 10/sup -20/ cm/sup 2//sec at 1000 deg C. PVDC carbon lost its adsorbed Xe at about the same rate as lampblack on exposure to air or HNO/sub 3/, though it differs from lampblack in being non-graphitizable and more porous. It had only a small diffused component, however. The results are discussed.

  3. Multi scale imaging of the Cloudy Zone in the Tazewell IIICD Meteorite

    Science.gov (United States)

    Einsle, J. F.; Harrison, R. J.; Nichols, C. I. O.; Blukis, R.; Midgley, P. A.; Eggeman, A.; Saghi, Z.; Bagot, P.

    2015-12-01

    Paleomagnetic studies of iron and stony iron meteorites suggest that many small planetary bodies possessed molten cores resulting in the generation of a magnetic field. As these bodies cooled, Fe-Ni metal trapped within their mantle underwent a series of low-temperature transitions, leading to the familiar Widmanstatten intergrowth of kamacite and taenite. Adjacent to the kamacite/taenite interface is the so-called "cloudy zone" (CZ): a nanoscale intergrowth of tetrataenite islands in an Fe-rich matrix phase formed via spinodal decomposition. It has recently been shown (Bryson et al. 2015, Nature) that the CZ encodes a time-series record of the evolution of the magnetic field generated by the molten core of the planetary body. Extracting meaningful paleomagnetic data from the CZ relies, on a thorough understanding of the 3D chemical and magnetic properties of the intergrowth focsusing on the interactions between the magnetically hard tetrataenite islands and the magnetically soft matrix. Here we present a multi scale study of the chemical and crystallographic make up of the CZ in the Tazewell IIICD meteorite, using a range of advanced microscopy techniques. The results provide unprecedented insight into the architecture of the CZ, with implications for how the CZ acquires chemical transformation remanance during cooling on the parent body. Previous 2D transmission electron microscope studies of the CZ suggested that the matrix is an ordered Fe3Ni phase with the L12 structure. Interpretation of the electron diffraction patterns and chemical maps in these studies was hindered by a failure to resolve signals from overlapping island and matrix phases. Here we obtain high resolution electron diffraction and 3D chemical maps with near atomic resolution using a combination of scanning precession electron diffraction, 3D STEM EDS and atom probe tomography. Using this combined methodology we reslove for the first time the phenomena of secondary precipitation in the

  4. Fluids on differentiated asteroids: Evidence from phosphates in differentiated meteorites GRA 06128 and GRA 06129

    Science.gov (United States)

    Shearer, Charles K.; Burger, Paul V.; Papike, James J.; Sharp, Zachary D.; McKeegan, Kevin D.

    2011-09-01

    Abstract- Paired meteorites Graves Nunatak 06128 and 06129 (GRA) represent an ancient cumulate lithology (4565.9 Ma ± 0.3) containing high abundances of sodic plagioclase. Textures and stable isotope compositions of GRA indicate that superimposed on the igneous lithology is a complex history of subsolidus reequilibration and low-temperature alteration that may have extended over a period of 150 Myr. In GRA, apatite is halogen-rich with Cl between 4.5 and 5.5 wt% and F between 0.3 and 0.9 wt%. The Cl/(Cl+F+OH) ratio of the apatite is between 0.65 and 0.82. The Cl and F are negatively correlated and are heterogeneously distributed in the apatite. Merrillite is low in halogens with substantial Na in the 6-fold coordinated Na-site (≈2.5%) and Mg in the smaller octahedral site. The merrillite has a negative Eu anomaly, whereas the apatite has a positive Eu anomaly. The chlorine isotope composition of the bulk GRA leachate is +1.2‰ relative to standard mean ocean chloride (SMOC). Ion microprobe chlorine isotope analyses of the apatite range between -0.5 and +1.2‰. Textural relationships between the merrillite and apatite, and the high-Cl content of the apatite, suggest that the merrillite is magmatic in origin, whereas the apatite is a product of the interaction between merrillite and a Cl-rich fluid. If the replacement of merrillite by apatite occurred at approximately 800 °C, the fluid composition is f(HCl)/f(H2O) = 0.0383 and a HCl molality of 2.13 and f(HCl)/f(HF) = 50-100. It is anticipated that the calculated f(HCl)/f(H2O) and a HCl molality are minimum values due to assumptions made on the OH component in apatite and basing the calculations on the apatite with the lowest XCl. The bulk δ37Cl of GRA is a >2σ outlier from chondritic meteorites and suggests that parent body processes resulted in fractionation of the Cl isotopes.

  5. p-process xenon isotope anomalies in stardust grains from meteorites

    International Nuclear Information System (INIS)

    Ott, U.

    2013-01-01

    Full text: In measurements on 'bulk' samples of meteorites isotopic variations due to the p-process usually have taken a backseat compared to such in s- or r-isotopes, and, in the best case, can be qualitatively attributed to the p-process, with little to no inferences concerning detailed isotopic yields. The situation is different for grains of stardust that survived in primitive meteorites. In fact, isotopically strange xenon was the key feature that led to the first identification of a stardust mineral, nanodiamonds containing xenon with overabundances of up to a factor of ∼2 in both the r-only (≡H-Xe) and p-only (≡L-Xe) isotopes. Relative excesses of the two r-only isotopes ( 134 Xe, 136 Xe) as well as of the two p-only isotopes ( 124 Xe, 126 Xe) are not equal, hence the processes responsible for HL-xenon must differ from the 'average' r- and p-processes as reflected in solar system abundances. However, while considerable effort has been put into explaining H-Xe, there has been little work on the p-side (L-Xe). Relying on scarce nuclear data, Heymann and Dziczkaniec have studied photodisintegration reactions of Xe and Ba seeds in intermediate zones of supernovae and found that the relative production of the p-Xe isotopes depends sensitively on the yield of the (γ, α) reaction on 128 Ba. Another suggestion - applicable to both the r- and p-anomalies in diamond xenon - is that of a 'rapid separation' between stable Xe isotopes and radioactive precursors produced in the 'standard' p- (as well as r-) process. For the p-isotopes to work, this would require the bulk (87%) of 126 Xe to be produced via the 126 Ba precursor, with a half live of ∼100 minutes, in order to explain the high 124 Xe/ 126 Xe. In contrast to diamond xenon, xenon in silicon carbide contains - besides the component from the s-process in their parent AGB stars - 'almost normal' Xe, with indications for 124 Xe/ 126 Xe being few (∼8)% lower than in solar Xe.

  6. Worldwide Weather Radar Imagery May Allow Substantial Increase in Meteorite Fall Recovery

    Science.gov (United States)

    Fries, Marc; Matson, Robert; Schaefer, Jacob; Fries, Jeffery; Hankey, Mike; Anderson, Lindsay

    2014-01-01

    Weather radar imagery is a valuable new technique for the rapid recovery of meteorite falls, to include falls which would not otherwise be recovered (e.g. Battle Mountain). Weather radar imagery reveals about one new meteorite fall per year (18 falls since 1998), using weather radars in the United States alone. However, an additional 75 other nations operate weather radar networks according to the UN World Meteorological Organization (WMO). If the imagery of those radars were analyzed, the current rate of meteorite falls could be improved considerably, to as much as 3.6 times the current recovery rate based on comparison of total radar areal coverage. Recently, the addition of weather radar imagery, seismometry and internet-based aggregation of eyewitness reports has improved the speed and accuracy of fresh meteorite fall recovery [e.g. 1,2]. This was demonstrated recently with the radar-enabled recovery of the Sutter's Mill fall [3]. Arguably, the meteorites recovered via these methods are of special scientific value as they are relatively unweathered, fresh falls. To illustrate this, a recent SAO/NASA ADS search using the keyword "meteorite" shows that all 50 of the top search results included at least one named meteorite recovered from a meteorite fall. This is true even though only 1260 named meteorite falls are recorded among the >49,000 individual falls recorded in the Meteoritical Society online database. The US NEXRAD system used thus far to locate meteorite falls covers most of the United States' surface area. Using a WMO map of the world's weather radars, we estimate that the total coverage of the other 75 national weather radar networks equals about 3.6x NEXRAD's coverage area. There are two findings to draw from this calculation: 1) For the past 16 years during which 18 falls are seen in US radar data, there should be an additional 65 meteorite falls recorded in worldwide radar imagery. Also: 2) if all of the world's radar data could be analyzed, the

  7. Express delivery of fossil meteorites from the inner asteroid belt to Sweden

    Science.gov (United States)

    Nesvorný, David; Vokrouhlický, David; Bottke, William F.; Gladman, Brett; Häggström, Therese

    2007-06-01

    Our understanding of planet formation depends in fundamental ways on what we learn by analyzing the composition, mineralogy, and petrology of meteorites. Yet, it is difficult to deduce the compositional and thermal gradients that existed in the solar nebula from the meteoritic record because, in most cases, we do not know where meteorites with different chemical and isotopic signatures originated. Here we developed a model that tracks the orbits of meteoroid-sized objects as they evolve from the ν secular resonance to Earth-crossing orbits. We apply this model to determining the number of meteorites accreted on the Earth immediately after a collisional disruption of a D˜200-km-diameter inner-main-belt asteroid in the Flora family region. We show that this event could produce fossil chondrite meteorites found in an ≈470 Myr old marine limestone quarry in southern Sweden, the L-chondrite meteorites with shock ages ≈470 Myr falling on the Earth today, as well as asteroid-sized fragments in the Flora family. To explain the measured short cosmic-ray exposure ages of fossil meteorites our model requires that the meteoroid-sized fragments were launched at speeds >500 m s -1 and/or the collisional lifetimes of these objects were much shorter immediately after the breakup event than they are today.

  8. AMSNEXRAD-Automated detection of meteorite strewnfields in doppler weather radar

    Science.gov (United States)

    Hankey, Michael; Fries, Marc; Matson, Rob; Fries, Jeff

    2017-09-01

    For several years meteorite recovery in the United States has been greatly enhanced by using Doppler weather radar images to determine possible fall zones for meteorites produced by witnessed fireballs. While most fireball events leave no record on the Doppler radar, some large fireballs do. Based on the successful recovery of 10 meteorite falls 'under the radar', and the discovery of radar on more than 10 historic falls, it is believed that meteoritic dust and or actual meteorites falling to the ground have been recorded on Doppler weather radar (Fries et al., 2014). Up until this point, the process of detecting the radar signatures associated with meteorite falls has been a manual one and dependent on prior accurate knowledge of the fall time and estimated ground track. This manual detection process is labor intensive and can take several hours per event. Recent technological developments by NOAA now help enable the automation of these tasks. This in combination with advancements by the American Meteor Society (Hankey et al., 2014) in the tracking and plotting of witnessed fireballs has opened the possibility for automatic detection of meteorites in NEXRAD Radar Archives. Here in the processes for fireball triangulation, search area determination, radar interfacing, data extraction, storage, search, detection and plotting are explained.

  9. A recent meteorite shower in Antarctica with an unusual orbital history

    Science.gov (United States)

    Benoit, P. H.; Sears, D. W. G.

    1993-01-01

    The Antarctic meteorite collection has proved to be a source of many important discoveries, including a number of previously unknown or very rare meteorite types. A thermoluminescence (TL) survey of meteorite samples recovered by the 1988/89 European expedition and pre-1988 American expeditions to the Allan Hills Main blue ice field resulted in the discovery of 15 meteorites with very high TL levels (greater than 100 krad at 250 C in the glow curve). It is likely that these samples are fragments of a single meteoroid body which: (1) fell very recently and (2) experienced a decrease in orbital perihelia from greater than or equal to 1.1 AU to 1 AU within the last 10(exp 5) yr. Carbon-14 data for two of the samples confirm their young terrestrial age compared to most Antarctic meteorites. Studies of the cosmogenic isotopes in at least one non-Antarctic meteorite which also has very high natural TL, Jilin, indicate that the meteorite experienced a multi-stage irradiation history, the most recent stage being 0.4 Ma in duration following a major break-up of the object. These meteorites, and the few equivalent modern falls, are the only documented samples from bodies which were recently in Earth-approaching (Amor) orbits (i.e., with perihelion greater than 1.0 AU), as opposed to the Earth-crossing (Apollo) orbits which are the source of most other meteorites. Their rarity indicates that such rapid orbit changes are unusual for meteoroid bodies and may be the result of isolated, large break-up events.

  10. SNC Meteorites, Organic Matter and a New Look at Viking

    Science.gov (United States)

    Warmflash, David M.; Clemett, Simon J.; McKay, David S.

    2001-01-01

    Recently, evidence has begun to grow supporting the possibility that the Viking GC-MS would not have detected certain carboxylate salts that could have been present as metastable oxidation products of high molecular weight organic species. Additionally, despite the instrument's high sensitivity, the possibility had remained that very low levels of organic matter, below the instrument's detection limit, could have been present. In fact, a recent study indicates that the degradation products of several million microorganisms per gram of soil on Mars would not have been detected by the Viking GC-MS. Since the strength of the GC-MS findings was considered enough to dismiss the biology packet, particularly the LR results, any subsequent evidence suggesting that organic molecules may in fact be present on the Martian surface necessitates a re-evaluation of the Viking LR data. In addition to an advanced mass spectrometer to look for isotopic signatures of biogenic processes, future lander missions will include the ability to detect methane produced by methanogenic bacteria, as well as techniques based on biotechnology. Meanwhile, the identification of Mars samples already present on Earth in the form of the SNC meteorites has provided us with the ability to study samples of the Martian upper crust a decade or more in advance of any planned sample return missions. While contamination issues are of serious concern, the presence of indigenous organic matter in the form of polycyclic aromatic hydrocarbons has been detected in the Martian meteorites ALH84001 and Nakhla, while there is circumstantial evidence for carbonaceous material in Chassigny. The radiochronological ages of these meteorites are 4.5 Ga, 1.3 Ga, and 165 Ma respectively representing a span of time in Earth history from the earliest single-celled organisms to the present day. Given this perspective on organic material, a biological interpretation to the Viking LR results can no longer be ruled out. In the LR

  11. Basic nitrogen-heterocyclic compounds in the Murchison meteorite

    International Nuclear Information System (INIS)

    Stoks, P.G.; Schwartz, A.W.

    1982-01-01

    A fragment of the Murchison (C2) carbonaceous meteorite was analyzed for basic, N-heterocyclic compounds, by dual detector capillary gas chromatography as well as capillary gas chromatography/mass spectrometry, using two columns of different polarity. In the formic acid extract 2,4,6-trimethylpyridine, quinoline, isoquinoline, 2-methylquinoline and 4-methylquinoline were positively identified. In addition, a suite of alkylpyridines and quinolines and/or isoquinolines was tentatively identified from their mass spectra. The (iso)quinolines were found to contain methyl substituents exclusively. The distribution of the pyridines observed reveals a similarity to that observed from catalytic reactions of ammonia and simple aldehydes under conditions similar to those applied in Fischer-Tropsch type reactions. (author)

  12. Evidence for extreme Ti-50 enrichments in primitive meteorites

    International Nuclear Information System (INIS)

    Fahey, A.; Mckeegan, K.D.; Zinner, E.; Goswami, J.N.; Physical Research Lab., Ahmedabad, India)

    1985-01-01

    The results of the first high mass resolution ion microprobe study of Ti isotopic compositions in individual refractory grains from primitive carbonaceous meteorites are reported. One hibonite from the Murray carbonaceous chondrite has a 10 percent excess of Ti-50, 25 times higher than the maximum value previously reported for bulk samples of refractory inclusions from carbonaceous chondrites. The variation of the Ti compositions between different hibonite grains, and among pyroxenes from a single Allende refractory inclusion, indicates isotopic inhomogeneities over small scale lengths in the solar nebula and emphasizes the importance of the analysis of small individual phases. This heterogeneity makes it unlikely that the isotopic anomalies were carried into the solar system in the gas phase. 20 references

  13. Paleomagnetism. Solar nebula magnetic fields recorded in the Semarkona meteorite.

    Science.gov (United States)

    Fu, Roger R; Weiss, Benjamin P; Lima, Eduardo A; Harrison, Richard J; Bai, Xue-Ning; Desch, Steven J; Ebel, Denton S; Suavet, Clément; Wang, Huapei; Glenn, David; Le Sage, David; Kasama, Takeshi; Walsworth, Ronald L; Kuan, Aaron T

    2014-11-28

    Magnetic fields are proposed to have played a critical role in some of the most enigmatic processes of planetary formation by mediating the rapid accretion of disk material onto the central star and the formation of the first solids. However, there have been no experimental constraints on the intensity of these fields. Here we show that dusty olivine-bearing chondrules from the Semarkona meteorite were magnetized in a nebular field of 54 ± 21 microteslas. This intensity supports chondrule formation by nebular shocks or planetesimal collisions rather than by electric currents, the x-wind, or other mechanisms near the Sun. This implies that background magnetic fields in the terrestrial planet-forming region were likely 5 to 54 microteslas, which is sufficient to account for measured rates of mass and angular momentum transport in protoplanetary disks. Copyright © 2014, American Association for the Advancement of Science.

  14. Accelerator mass analyses of meteorites - carbon-14 terrestrial ages

    International Nuclear Information System (INIS)

    Miura, Y.; Rucklidge, J.; Beukens, R.; Fireman, E.

    1988-01-01

    Carbon-14 terrestrial ages of ten Antarctic meteorites have been measured by the IsoTrace accelerator mass spectrometry (AMS). The 14 C terrestrial age of 1 gram sample was determined from 14 C concentrations collected at melt and re-melt temperatures, compared with the 14 C concentration of the known Bruderheim chondrite. Yamato-790448 (LL3) chondrite was found to be the oldest terrestrial age of 3x10 4 years in the nine Yamato chondrites, whereas Yamato-791630 (L4) chondrite is considered to be the youngest chondrites less than thousand years. Allan Hills chondrite of ALH-77231 (L6) shows older terrestrial age than the nine Yamato chondrites. New accelerator data of the terrestrial age show higher accuracy with smaller sample than the previous counting method. (author)

  15. Phase analysis of Košice meteorite: Preliminary results

    Science.gov (United States)

    Sitek, J.; Dekan, J.; Degmová, J.; Sedlačková, K.

    2012-10-01

    Meteorite fall was observed by the Košice town in Slovakia in February 2010 and it was classified as an ordinary chondrite H5. The samples were prepared in powder form scratched from the surface. Mossbauer spectra were measured at room temperature and liquid nitrogen temperature. Spectra consist of components related to iron-bearing phases with different content. Non-magnetic part was fitted with three quadrupole doublets. According to its parameters, we identified olivine, pyroxene, and traces of Fe3+ phases. Magnetic part consists of an iron-rich Fe-Ni alloy with hyperfine magnetic field similar to kamacite α-Fe(Ni,Co) and troilite. Main elements were also determined by X-ray fluorescence spectroscopy.

  16. Investigation of Isotope Anomalies in Meteorites and their Components

    DEFF Research Database (Denmark)

    Holst, Jesper Christian

    Cosmochemistry aims to clarify the origin of our solar system and the preconditions for life as we know it. Through the study of meteorites, it is possible to constrain our Sun’s birth environment, the formation and the evolution of the protoplanetary disk of dust and gas that evolved...... then terminated their evolution either on the asymptotic giant branch (AGB) or in supernova explosions at the time when low mass stars like our Sun were forming. In this way, matter incorporated into the nascent solar system must have had diverse origins, some being old inherited presolar grains, others being...... the bulk solar system. Therefore, in order to establish a detailed history of the early solar system and processing of the protoplanetary disk, it is critical to ascertain the isotope variability of a large range of elements of different nucleosynthetic origin. In this thesis, we establish methods...

  17. Meteoritic Stardust and the Presolar History of the Solar Neighborhood

    Science.gov (United States)

    Nittler, Larry R.

    Presolar stardust is present at low levels in meteorites and cometary dust and identified as ancient stellar matter by unusual isotopic compositions reflecting nuclear processes in stellar interiors and galactic chemical evolution. Most grains originated in winds from asymptotic giant branch (AGB) stars and supernova and their isotopic compositions provide important constraints on models of evolution and nucleosynthesis in these environments. The presolar grains from AGB stars appear to have formed in a lower-mass population of stars than predicted by GCE models. A merger of the Milky Way with a dwarf galaxy some 1 Gyr before the birth of the Solar System may explain this and other grain observations and the data thus can provide a unique window into the presolar history of the solar neighborhood.

  18. Refractory metal particles in refractory inclusions in the Allende meteorite

    International Nuclear Information System (INIS)

    Fuchs, L.H.; Blander, M.

    1980-01-01

    An examination of refractory metal particles in five calcium-aluminum-rich inclusions in the Allende meteorite indicates a complex variety of compositions and large departures from equilibrium. These particles appear to have been primordial condensates which were isolated from the nebula and from each other at different times by cocondensing oxides. Selective diffusion and/or oxidation of the more oxidizable metals (Mo, W, Fe and Ni), phase segregations into different alloy phases (fcc, bcc, hcp and perhaps ordered phases) and the formation of metastable condensates appears to have been involved in the modification of these materials to their present state. Only a small fraction of our observations cannot be reconciled with this picture because of a lack of knowledge of some of the phase equilibria which might have bee involved

  19. Moessbauer studies on the paramagnetic porton of alkidirat meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, Huda Mohamed [Department of Physics, Faculty of Science, University of Khartoum, Khartoum (Sudan)

    1995-11-01

    This work was performed on a sample from alkidirat meteorite which fell west of Sudan by means of Moessbauer effect spectrometer. results showed the absence of transition temperature from the paramagnetic state to the magnetic state in the temperature range from 300K down to 16K. Also, it was found that olivine and ortho pyroxene exist together in site M{sup 1}, while clinothyroxene exists alone in site M{sup 2}. Formula for the composition of ortho pyroxene in the sample were also obtained and they were in good agreement with previous studies. The disorder parameter was also calculated and it showed that the pyroxene present in the sample is well-ordered.(Author) 37 refs. , 2 tabs. , 19 figs.

  20. Organic chemistry of Murchison meteorite: Carbon isotopic fractionation

    Science.gov (United States)

    Yuen, G. U.; Blair, N. E.; Desmarais, D. J.; Cronin, J. R.; Chang, S.

    1986-01-01

    The carbon isotopic composition of individual organic compounds of meteoritic origin remains unknown, as most reported carbon isotopic ratios are for bulk carbon or solvent extractable fractions. The researchers managed to determine the carbon isotopic ratios for individual hydrocarbons and monocarboxylic acids isolated from a Murchison sample by a freeze-thaw-ultrasonication technique. The abundances of monocarboxylic acids and saturated hydrocarbons decreased with increasing carbon number and the acids are more abundant than the hydrocarbon with the same carbon number. For both classes of compounds, the C-13 to C-12 ratios decreased with increasing carbon number in a roughly parallel manner, and each carboxylic acid exhibits a higher isotopic number than the hydrocarbon containing the same number of carbon atoms. These trends are consistent with a kinetically controlled synthesis of higher homologues for lower ones.

  1. Chemical fractionations in meteorites. IX. C3 chondrites

    Energy Technology Data Exchange (ETDEWEB)

    Anders, E; Higuchi, H; Ganapathy, R; Morgan, J W [Chicago Univ., Ill. (USA). Enrico Fermi Inst.

    1976-09-01

    Four C3V chondrites (Grosnaja, Kaba, Mokoia, Vigarano) and three C30 chondrites (Felic, Kainsaz, and Lance) were analyzed by radiochemical neutron activation for 17 trace elements. Both classes show a typical chondritic step pattern, reflecting loss of volatiles during chondrule formation. Elements condensing above 1300 K (U, Re, Ir, Ni) are present in essentially C1 chondrite proportions, while moderately volatile elements condensing between 1300 K and 800 K (Ge, Rb, Ag) are depleted by a factor of 0.44. However, elements condensing below 700 K (S, Cs, Bi, Tl, Br, Se, Te, In, Cd) are depleted to a still greater degree, and more so in the Ornans subclass (factor of 0.24, except Cd 0.007) than in the Vigarano subclass (factor of 0.29). This additional depletion may be due to a slight (less than 3-fold) dust-gas fractionation, by settling of dust to the median plane of the solar nebula. Among other chondrite classes, ordinary chondrites show a similar depletion, but C2 chondrites do not. Possibly the undepleted meteorites formed in one of the convection zones of the nebula predicted by Cameron and Pine, whereas the depleted meteorites formed in a quiescent region. The condensation of chalocophile elements as a function of H/sub 2/S partial pressure is discussed, in an attempt to explain the drastic difference in Cd abundance between the two subclasses. It appears that the H/sub 2/S/H/sub 2/ ratio is the key variable. C30's seem to have condensed in a region where enough metallic Fe was present to buffer the H/sub 2/S pressure, while C3V's condensed in a more oxidized region, where H/sub 2/S was in excess. Accretion temperatures, for an assumed nebular pressure of 10/sup -5/ atm, were between 415 and 430 K for C30's and less than 440 K for CeV's.

  2. Ar-Ar dating techniques for terrestrial meteorite impacts

    Science.gov (United States)

    Kelley, S. P.

    2003-04-01

    The ages of the largest (>100 km) known impacts on Earth are now well characterised. However the ages of many intermediate sized craters (20-100 km) are still poorly known, often the only constraints are stratigraphic - the difference between the target rock age and the age of crater filling sediments. The largest impacts result in significant melt bodies which cool to form igneous rocks and can be dated using conventional radiometric techniques. Smaller impacts give rise to thin bands of melted rock or melt clasts intimately mixed with country rock clasts in breccia deposits, and present much more of a challenge to dating. The Ar-Ar dating technique can address a wide variety of complex and heterogeneous samples associated with meteorite impacts and obtain reasonable ages. Ar-Ar results will be presented from a series of terrestrial meteorite impact craters including Boltysh (65.17±0.64 Ma, Strangways (646±42 Ma), and St Martin (220±32 Ma) and a Late Triassic spherule bed, possibly representing distal deposits from Manicouagan (214±1 Ma) crater. Samples from the Boltysh and Strangways craters demonstrate the importance of rapid cooling upon the retention of old ages in glassy impact rocks. A Late Triassic spherule bed in SW England is cemented by both carbonate and K-feldspar cements allowing Ar-Ar dating of fine grained cement to place a mimimum age upon the age of the associated impact. An age of 214.7±2.5 Ma places the deposit with errors of the age of the Manicouagan impact, raising the possibility that it may represent a distal deposit (the deposit lay around 2000 km away from the site of the Manicouagan crater during the Late Triassic). Finally the limits of the technique will be demonstrated using an attempt to date melt rocks from the St Martin Crater in Canada.

  3. Allochthonous Addition of Meteoritic Organics to the Lunar Regolith

    Science.gov (United States)

    Thomas-Keprta, K. L.; Clemett, S.; Ross, D. K.; Le, L.; Rahman, Z.; McKay, D. S.; Gibson, E. K.; Gonzalez, C.

    2013-01-01

    Preparation of lunar samples 74220,861 was discussed in detail in [3, 4]. Our analysis sequence was as follows: optical microscopy, UV fluorescence imaging, -Raman, FESEM-EDX imaging and mapping, FETEMEDX imaging and mapping of a Focused Ion Beam (FIB) extracted section, and NanoSIMs analysis. We observed fluffytextured C-rich regions of interest (ROI) on three different volcanic glass beads. Each ROI was several m2 in size and fluoresced when exposed to UV. Using FESEM/EDX, the largest ROI measured 36 m and was located on an edge of a plateau located on the uppermost surface of the bead. The ROI was covered on one edge by a siliceous filament emanating from the plateau surface indicating it was attached to the bead while on the Moon. EDX mapping of the ROI shows it is composed primarily of heterogeneously distributed C. Embedded with the carbonaceous phase are localized concentrations of Si, Fe, Al and Ti indicating the presence of glass and/or minerals grains. -Raman showed strong D- and G-bands and their associated second order bands; intensity and location of these bands indicates the carbonaceous matter is structurally disorganized. A TEM thin section was extracted from the surface of a glass bead using FIB microscopy. High resolution TEM imaging and selected area electron diffraction demonstrate the carbonaceous layer to be amorphous; it lacked any long or short range order characteristic of micro- or nanocrystalline graphite. Additionally TEM imaging also revealed the presence of submicron mineral grains, typically < 50 nm in size, dispersed within the carbonaceous layer. NanoSIMs data will be presented and discussed at the meeting. Given the noted similarities between the carbonaceous matter present on 74220 glass beads and meteoritic kerogen, we suggest the allochthonous addition of meteoritic organics as the most probable source for the C-rich ROIs.

  4. INAA of CAIs from the Maralinga CK4 chondrite: Effects of parent body thermal metamorphism

    Science.gov (United States)

    Lindstrom, D. J.; Keller, L. P.; Martinez, R. R.

    1993-01-01

    Maralinga is an anomalous CK4 carbonaceous chondrite which contains numerous Ca-, Al-rich inclusions (CAI's) unlike the other members of the CK group. These CAI's are characterized by abundant green hercynitic spinel intergrown with plagioclase and high-Ca clinopyroxene, and a total lack of melilite. Instrumental Neutron Activation Analysis (INAA) was used to further characterize the meteorite, with special focus on the CAI's. High sensitivity INAA was done on eight sample disks about 100-150 microns in diameter obtained from a normal 30 micron thin section with a diamond microcoring device. The CAI's are enriched by 60-70X bulk meteorite values in Zn, suggesting that the substantial exchange of Fe for Mg that made the spinel in the CAI's hercynitic also allowed efficient scavenging of Zn from the rest of the meteorite during parent body thermal metamorphism. Less mobile elements appear to have maintained their initial heterogeneity.

  5. Falling sky the science and history of meteorites and why we should learn to love them

    CERN Document Server

    Nield, Ted

    2011-01-01

    Did an enormous collision in the Asteroid Belt, orbiting the sun between Mars and Jupiter, bombard Earth with meteorites 470 million years ago? Astonishing new research suggests it did, and a revolutionary theory is emerging that this bombardment resulted in the single greatest increase in biological diversity on the planet since the origin of life. Introducing these discoveries to the general public for the first time, Ted Nield challenges the view that meteorites are bad news. Tracing the history of meteorites from the first recorded strike to the videos made routinely today, he reveals the fascinating ways in which meteorites have transformed from omens of doom to a stepping stone to Mars in twenty-first-century space exploration. The Falling Sky will shatter everything you thought you knew about one of the most terrifying forces in the universe.

  6. Minor bodies of the Solar system: meteorite orbits, relationship, mirror symmetry in C-distribution

    International Nuclear Information System (INIS)

    Terent'eva, A.K.

    1989-01-01

    Population of large meteor bodies having masses from several kilograms up to several tens of tons has been revealed by means of photographic observations of bright fireballs. 39 of 69 objects of this population is meteorites producing. A unique class of meteorite orbits of an extremely short period (the Earth's group) has been found. The analysis of the distributions of minor bodies by Tisserand constant C (the perturbing planet is Jupiter) allowed to make conclusions about possible genetic connections and families inside the complex of minor bodies - comets, asteroids, large meteor bodies including meteorites and meteor streams. About 8 per cent of meteorites and 15 per cent of asteroids of the Amour group may have a cometary origin. Mirror symmetry has been found in C-distribution of minor bodies relative to the gap in the center of which collinear points of libration are located

  7. Mineralogical Composition of the Mexican Ordinary Chondrite Type Meteorite: A Raman, Infrared and XRD Study

    Science.gov (United States)

    Ostrooumov, M.

    2016-08-01

    The Raman microprobe (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of seven mexican meteorites: Aldama, Cosina, El Pozo, Escalon, Nuevo Mercurio,Pacula, Zapotitlan Salinas.

  8. Constraining the Source Craters of the Martian Meteorites: Implications for Prioritiziation of Returned Samples from Mars

    Science.gov (United States)

    Herd, C. D. K.; Tornabene, L. L.; Bowling, T. J.; Walton, E. L.; Sharp, T. G.; Melosh, H. J.; Hamilton, J. S.; Viviano, C. E.; Ehlmann, B. L.

    2018-04-01

    We have made advances in constraining the potential source craters of the martian meteorites to a relatively small number. Our results have implications for Mars chronology and the prioritization of samples for Mars Sample Return.

  9. Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites.

    Science.gov (United States)

    Cooper, George; Rios, Andro C

    2016-06-14

    Biological polymers such as nucleic acids and proteins are constructed of only one-the d or l-of the two possible nonsuperimposable mirror images (enantiomers) of selected organic compounds. However, before the advent of life, it is generally assumed that chemical reactions produced 50:50 (racemic) mixtures of enantiomers, as evidenced by common abiotic laboratory syntheses. Carbonaceous meteorites contain clues to prebiotic chemistry because they preserve a record of some of the Solar System's earliest (∼4.5 Gy) chemical and physical processes. In multiple carbonaceous meteorites, we show that both rare and common sugar monoacids (aldonic acids) contain significant excesses of the d enantiomer, whereas other (comparable) sugar acids and sugar alcohols are racemic. Although the proposed origins of such excesses are still tentative, the findings imply that meteoritic compounds and/or the processes that operated on meteoritic precursors may have played an ancient role in the enantiomer composition of life's carbohydrate-related biopolymers.

  10. The Distinct Genetics of Carbonaceous and Non-Carbonaceous Meteorites Inferred from Molybdenum Isotopes

    Science.gov (United States)

    Budde, G.; Burkhardt, C.; Kleine, T.

    2017-07-01

    Mo isotope systematics manifest a fundamental dichotomy in the genetic heritage of carbonaceous and non-carbonaceous meteorites. We discuss its implications in light of the most recent literature data and new isotope data for primitive achondrites.

  11. Silver contents and Cu/Ag ratios in Martian meteorites and the implications for planetary differentiation

    Science.gov (United States)

    Wang, Zaicong; Becker, Harry

    2017-11-01

    Silver and Cu show very similar partitioning behavior in sulfide melt-silicate melt and metal-silicate systems at low and high pressure-temperature (P-T) experimental conditions, implying that mantle melting, fractional crystallization and core-mantle differentiation have at most modest (within a factor of 3) effects on Cu/Ag ratios. For this reason, it is likely that Cu/Ag ratios in mantle-derived magmatic products of planetary bodies reflect that of the mantle and, in some circumstances, also the bulk planet composition. To test this hypothesis, new Ag mass fractions and Cu/Ag ratios in different groups of Martian meteorites are presented and compared with data from chondrites and samples from the Earth's mantle. Silver contents in lherzolitic, olivine-phyric and basaltic shergottites and nakhlites range between 1.9 and 12.3 ng/g. The data display a negative trend with MgO content and correlate positively with Cu contents. In spite of displaying variable initial Ɛ143Nd values and representing a diverse spectrum of magmatic evolution and physiochemical conditions, shergottites and nakhlites display limited variations of Cu/Ag ratios (1080 ± 320, 1 s, n = 14). The relatively constant Cu/Ag suggests limited fractionation of Ag from Cu during the formation and evolution of the parent magmas, irrespectively of whether sulfide saturation was attained or not. The mean Cu/Ag ratio of Martian meteorites thus reflects that of the Martian mantle and constrains its Ag content to 1.9 ± 0.7 ng/g (1 s). Carbonaceous and enstatite chondrites display a limited range of Cu/Ag ratios of mostly 500-2400. Ordinary chondrites show a larger scatter of Cu/Ag up to 4500, which may have been caused by Ag redistribution during parent body metamorphism. The majority of chondrites have Cu/Ag ratios indistinguishable from the Martian mantle value, indicating that Martian core formation strongly depleted Cu and Ag contents, but probably did not significantly change the Cu/Ag ratio of the

  12. Uranium isotope ratios of Muonionalusta troilite and complications for the absolute age of the IVA iron meteorite core

    Science.gov (United States)

    Brennecka, Gregory A.; Amelin, Yuri; Kleine, Thorsten

    2018-05-01

    The crystallization ages of planetary crustal material (given by basaltic meteorites) and planetary cores (given by iron meteorites) provide fiducial marks for the progress of planetary formation, and thus, the absolute ages of these objects fundamentally direct our knowledge and understanding of planet formation and evolution. The lone precise absolute age of planetary core material was previously obtained on troilite inclusions from the IVA iron meteorite Muonionalusta. This previously reported Pb-Pb age of 4565.3 ± 0.1 Ma-assuming a 238U/235U =137.88-only post-dated the start of the Solar System by approximately 2-3 million years, and mandated fast cooling of planetary core material. Since an accurate Pb-Pb age requires a known 238U/235U of the sample, we have measured both 238U/235U and Pb isotopic compositions of troilite inclusions from Muonionalusta. The measured 238U/235U of the samples range from ∼137.84 to as low as ∼137.22, however based on Pb and U systematics, terrestrial contamination appears pervasive and has affected samples to various extents for Pb and U. The cause of the relative 235U excess in one sample does not appear to be from terrestrial contamination or the decay of short-lived 247Cm, but is more likely from fractionation of U isotopes during metal-silicate separation during core formation, exacerbated by the extreme U depletion in the planetary core. Due to limited Pb isotopic variation and terrestrial disturbance, no samples of this study produced useful age information; however the clear divergence from the previously assumed 238U/235U of any troilite in Muonionalusta introduces substantial uncertainty to the previously reported absolute age of the sample without knowledge of the 238U/235U of the sample. Uncertainties associated with U isotope heterogeneity do not allow for definition of a robust age of solidification and cooling for the IVA core. However, one sample of this work-paired with previous work using short

  13. Comparisons of PGA and INAA in the analyses of meteorite samples

    International Nuclear Information System (INIS)

    Wee Boon Siong; Ebihara, M.; Abdul Khalik Wood

    2010-01-01

    Prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA) are suitable methods for multi-elemental determinations in various samples. These two methods are complementary because PGA is capable of analyzing most major and minor elements in rock samples whereas INAA is more superior in determining minor and trace elements. Both PGA and INAA are essential for the study of rare samples such as meteorites because of non-destructivity and relatively being free from contaminations. Samples for PGA can be reused for INAA, which help to reduce the sample usage. This project aims to utilize PGA and INAA techniques for comparative study and apply them to meteorites. In this study, 11 meteorite samples received from the Meteorite Working Group of NASA were analyzed. The Allende meteorite powder was included as quality control material. Results from PGA and INAA for Allende showed good agreement with literature values, signifying the reliabilities of these two methods. Elements Al, Ca, Mg, Mn, Na and Ti were determined by both methods and their results are compared. Comparison of PGA and INAA data using linear regression analysis showed correlations coefficients r 2 > 0.90 for Al, Ca, Mn and Ti, 0.85 for Mg, and 0.38 for Na. The PGA results for Na using 472 keV were less accurate due to the interference from the broad B peak. Therefore, Na results from INAA method are preferred. For other elements (Al, Ca, Mg, Mn and Ti), PGA and INAA results can be used as cross-reference for consistency. The PGA and INAA techniques have been applied to meteorite samples and results are comparable to literature values compiled from previously analyzed meteorites. In summary, both PGA and INAA methods give reasonably good agreement and are indispensable in the study of meteorites. (author)

  14. Micro-Raman spectroscopy of plagioclase and maskelynite in Martian meteorites: Evidence of progressive shock metamorphism

    OpenAIRE

    Fritz,Jorg; Greshake,Ansgar; Stoffler,Dieter

    2005-01-01

    We present the first systematic Micro-Raman spectroscopic investigation of plagioclase of different degree of shock metamorphism in Martian meteorites. The equilibrium shock pressure of all plagioclase phases of seventeen unpaired Martian meteorites was determined by measuring the shock-induced reduction of the refractive index. Systematic variations in the recorded Raman spectra of the plagioclase phases correlate with increasing shock pressure. In general, the shock induced deformation of t...

  15. Qualitative Elemental Analyses of a Meteorite Sample Found in Turkey by Photo-activation Analysis Method

    International Nuclear Information System (INIS)

    Ertugay, C; Boztosun, I; Ozmen, S F; Dapo, H

    2015-01-01

    In this paper, a meteorite sample provided from TÜBITAK National Observatory found in Turkey has been investigated by using a clinical linear accelerator that has endpoint energy of 18 MeV, and a high purity Germanium detector for qualitative elemental analysis within photo-activation analysis method. 21 nuclei ranging from 24Na to 149Nd have been identified in the meteorite sample. (paper)

  16. Lunar Meteorites Sayh Al Uhaymir 449 and Dhofar 925, 960, and 961: Windows into South Pole

    Science.gov (United States)

    Ziegler, Ryan A.; Jolliff, B. L.; Korotev, R. L.

    2013-01-01

    In 2003, three lunar meteorites were collected in close proximity to each other in the Dhofar region of Oman: Dhofar 925 (49 g), Dhofar 960 (35 g), and Dhofar 961 (22 g). In 2006, lunar meteorite Sayh al Uhaymir (SaU) 449 (16.5 g) was found about 100 km to the NE. Despite significant differences in the bulk composition of Dhofar 961 relative to Dhofar 925/960 and SaU 449 (which are identical to each other), these four meteorites are postulated to be paired based on their find locations, bulk composition, and detailed petrographic analysis. Hereafter, they will collectively be referred to as the Dhofar 961 clan. Comparison of meteorite and component bulk compositions to Lunar Prospector 5-degree gamma-ray data suggest the most likely provenance of this meteorite group is within the South Pole-Aitken Basin. As the oldest, largest, and deepest recognizable basin on the Moon, the composition of the material within the SPA basin is of particular importance to lunar science. Here we review and expand upon the geochemistry and petrography of the Dhofar 961 clan and assess the likelihood that these meteorites come from within the SPA basin based on their bulk compositions and the compositions and characteristics of the major lithologic components found within the breccia.

  17. Carbon Isotope Analyses of Individual Hydrocarbon Molecules in Bituminous Coal, Oil Shale and Murchison Meteorite

    Directory of Open Access Journals (Sweden)

    Kyoungsook Kim

    1998-06-01

    Full Text Available To study the origin of organic matter in meteorite, terrestrial rocks which contain organic compounds similar to the ones found in carbonaceous chondrites are studied and compared with Murchison meteorite. Hydrocarbon molecules were extracted by benzene and methanol from bituminous coal and oil shale and the extracts were partitioned into aliphatic, aromatic, and polar fractions by silica gel column chromatography. Carbon isotopic ratios in each fractions were analysed by GC-C-IRMS. Molecular compound identifications were carried by GC-MS Engine. Bituminous coal and oil shale show the organic compound composition similar to that of meteorite. Oil shale has a wide range of δ(13C, -20.1%_0 - -54.4%_0 compared to bituminous coal, -25.2%_0 - -34.3%_0. Delta values of several molecular compounds in two terrestrial samples are different. They show several distinct distributions in isotopic ratios compared to those of meteorite; Murchison meteorite has a range of δ(13C from -13%_0 to +30%_0. These results provide interpretation for the source and the formation condition of each rock, in particular alteration and migration processes of organic matter. Especially, they show an important clue whether some hydrocarbon molecules observed in meteorite are indigenous or not.

  18. The Virtual Museum for Meteorites: an Online Tool for Researchers Educators and Students

    Science.gov (United States)

    Madiedo, J. M.

    2013-09-01

    The Virtual Museum for Meteorites (Figure 1) was created as a tool for students, educators and researchers [1, 2]. One of the aims of this online resource is to promote the interest in meteorites. Thus, the role of meteorites in education and outreach is fundamental, as these are very valuable tools to promote the public's interest in Astronomy and Planetary Sciences. Meteorite exhibitions reveal the fascination of students, educators and even researchers for these extraterrestrial rocks and how these can explain many key questions origin and evolution of our Solar System. However, despite the efforts related to the origin and evolution of our Solar System. However, despite the efforts of private collectors, museums and other institutions to organize meteorite exhibitions, the reach of these is usually limited. The Virtual Museum for Meteorites takes advantage of HTML and related technologies to overcome local boundaries and offer its contents for a global audience. A description of the recent developments performed in the framework of this virtual museum is given in this work.

  19. Magnetic susceptibility of 244Cm metal and 249Cf metal

    International Nuclear Information System (INIS)

    Fujita, D.K.; Parsons, T.C.; Edelstein, N.; Noe, M.; Peterson, J.R.

    1975-07-01

    The first magnetic susceptibility measurements made on the expanded fcc phase of 249 Cf metal are reported. Further measurements are needed on other Cf metal phases. Another measurement of the magnetic susceptibility of 244 Cm metal in a limited temperature range has been reported. The result does not agree with previously reported values. Further work is continuing on the synthesis of 244 Cm metal and 248 Cm metal and magnetic measurements on these samples. (auth)

  20. Effects of electron irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells

    Science.gov (United States)

    Nicoletta, C. A.

    1973-01-01

    One OHM-cm and 10 OHM-cm silicon solar cells were exposed to 1.0 MeV electrons at a fixed flux of 10 to the 11th power e/sq cm/sec and fluences of 10 to the 13th power, 10 to the 14th power and 10 to the 15th power e/sq.cm. 1-V curves of the cells were made at room temperature, - 63 C and + or - 143 C after each irradiation. A value of 139.5 mw/sq cm was used as AMO incident energy rate per unit area. The 10 OHM-cm cells appear more efficient than 1 OHM-cm cells after exposure to a fluence greater than 10 to the 14th power e/sq cm. The 1.0 MeV electron damage coefficients for both 1 OHM-cm and 10 OHM-cm cells are somewhat less than those for previously irradiated cells at room temperature. The values of the damage coefficients increase as the cell temperatures decrease. Efficiencies pertaining to maximum power output are about the same as those of n on p silicon cells evaluated previously.

  1. Educating the Public about Meteorites and Impacts through Virtual Field Trips and Classroom Experience Boxes

    Science.gov (United States)

    Ashcraft, Teresa; Hines, R.; Minitti, M.; Taylor, W.; Morris, M. A.; Wadhwa, M.

    2014-01-01

    With specimens representing over 2,000 individual meteorites, the Center for Meteorite Studies (CMS) at Arizona State University (ASU) is home to the world's largest university-based meteorite collection. As part of our mission to provide educational opportunities that expand awareness and understanding of the science of meteoritics, CMS continues to develop new ways to engage the public in meteorite and space science, including the opening of a new Meteorite Gallery, and expansion of online resources through upgrades to the CMS website, meteorites.asu.edu. In 2008, CMS was the recipient of a philanthropic grant to improve online education tools and develop loanable modules for educators. These modules focus on the origin of meteorites, and contain actual meteorite specimens, media resources, a user guide, and lesson plans, as well as a series of engaging activities that utilize hands-on materials geared to help students develop logical thinking, analytical skills, and proficiency in STEM disciplines. In 2010, in partnership with the ASU NASA Astrobiology Institute team, CMS obtained a NASA EPOESS grant to develop Virtual Field Trips (VFTs) complemented by loanable “Experience Boxes” containing lesson plans, media, and hands-on objects related to the VFT sites. One VFT-Box pair focuses on the record of the oldest multicellular organisms on Earth. The second VFT-Box pair focuses on the Upheaval Dome (UD) structure, a meteorite impact crater in Utah’s Canyonlands National Park. UD is widely accepted as the deeply eroded remnant of a ~5 kilometer impact crater (e.g. Kriens et al., 1999). The alternate hypothesis that the Dome was formed by the upwelling of salt from a deposit underlying the region (e.g. Jackson et al., 1998) makes UD an ideal site to learn not only about specific scientific principles present in the Next Generation Science Standards, but also the process of scientific inquiry. The VFTs are located on an interactive website dedicated to VFTs, vft

  2. Unmelted meteoritic debris in the Late Pliocene iridium anomaly - Evidence for the ocean impact of a nonchondritic asteroid

    Science.gov (United States)

    Kyte, F. T.; Brownlee, D. E.

    1985-01-01

    Ir-bearing particles have been recovered from two piston cores in the Antarctic Basin in the southeastern Pacific. In core E13-3, the particles closely correspond to the Late Pliocene Ir anomaly and have a fluence of about 100 mg/cm sq. In core E13-4, 120 km to the southwest, the particle fluence is about 4 mg/cm sq. Particles with diameters from 0.5 to 4 mm contain at least 35 percent of the Ir in this horizon. Three types of particles have been identified: (1) vesicular, (2) basaltic, and (3) metal. The vesicular particles appear to be shock-melted debris derived from the oceanic impact of a howarditic asteroid containing a minor metal component. These particles have recrystallized from a melt and impact into the ocean has resulted in the incorporation of Na, K, Cl, and radiogenic Sr from the ocean water target. The basaltic clasts appear to be unmelted fragments of the original asteroid which may have separated from the main body prior to impact. Combined vesicular and basaltic particles are believed to have formed by collisions in the debris cloud. Estimates of the diameter of the projectile range from 100 to 500 m. By many orders of magnitude, this is the most massive achondrite sampled by a single meteorite fall.

  3. RAPID TIMESCALES FOR MAGMA OCEAN CRYSTALLIZATION ON THE HOWARDITE-EUCRITE-DIOGENITE PARENT BODY

    International Nuclear Information System (INIS)

    Schiller, Martin; Paton, Chad; Bizzarro, Martin; Baker, Joel; Creech, John; Millet, Marc-Alban; Irving, Anthony

    2011-01-01

    Asteroid 4 Vesta has long been postulated as the source for the howardite-eucrite-diogenite (HED) achondrite meteorites. Here we show that Al-free diogenite meteorites record variability in the mass-independent abundance of 26 Mg ( 26 Mg*) that is correlated with their mineral chemistry. This suggests that these meteorites captured the Mg-isotopic evolution of a large-scale differentiating magma body with increasing 27 Al/ 24 Mg during the lifespan of the short-lived 26 Al nuclide (t 1/2 ∼ 730,000 yr). Thus, diogenites and eucrites represent crystallization products of a large-scale magma ocean associated with the differentiation and magmatic evolution of the HED parent body. The 26 Mg* composition of the most primitive diogenites requires onset of the magma ocean crystallization within 0.6 -0.4 +0.5 Myr of solar system formation. Moreover, 26 Mg* variations among diogenites and eucrites imply that near complete solidification of the HED parent body occurred within the following 2-3 Myr. Thermal models predict that such rapid cooling and magma ocean crystallization could only occur on small asteroids (<100 km), implying that 4 Vesta is not the source of the HED meteorites.

  4. 2-cm versus 4-cm surgical excision margins for primary cutaneous melanoma thicker than 2 mm: a randomised, multicentre trial

    DEFF Research Database (Denmark)

    Gillgren, Peter; Drzewiecki, Krzysztof T; Niin, Marianne

    2011-01-01

    Optimum surgical resection margins for patients with clinical stage IIA-C cutaneous melanoma thicker than 2 mm are controversial. The aim of the study was to test whether survival was different for a wide local excision margin of 2 cm compared with a 4-cm excision margin.......Optimum surgical resection margins for patients with clinical stage IIA-C cutaneous melanoma thicker than 2 mm are controversial. The aim of the study was to test whether survival was different for a wide local excision margin of 2 cm compared with a 4-cm excision margin....

  5. Effects of proton irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells

    Science.gov (United States)

    Nicoletta, C. A.

    1973-01-01

    The 1 ohm-cm and 10 ohm-cm silicon solar cells were exposed to 1.0 MeV protons at a fixed flux of 10 to the 9th power P/sq cm-sec and fluences of 10 to the 10th power, 10 to the 11th power, 10 to the 12th power and 3 X 10 to the 12th power P/sq cm. I-V curves of the cells were made at room temperature, 65 C and 165 C after each irradiation. A value of 139.5 mw/sq cm was taken as AMO incident energy rate per unit area. Degradation occurred for both uncovered 1 ohm-cm and 10 ohm-cm cells. Efficiencies are generally higher than those of comparable U.S. cells tested earlier. Damage (loss in maximum power efficiency) with proton fluence is somewhat higher for 10 ohm-cm cells, measured at the three temperatures, for fluences above 2 X 10 to the 11th power P/sq cm. Cell efficiency, as expected, changes drastically with temperature.

  6. The Panther Mountain circular structure, a possible buried meteorite crater

    Science.gov (United States)

    Isachsen, Y. W.; Wright, S. F.; Revetta, F. A.; Duneen, R. J.

    Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon.

  7. Effects of meteorite impacts on the atmospheric evolution of Mars.

    Science.gov (United States)

    Pham, Lê Binh San; Karatekin, Ozgür; Dehant, Véronique

    2009-01-01

    Early in its history, Mars probably had a denser atmosphere with sufficient greenhouse gases to sustain the presence of stable liquid water at the surface. Impacts by asteroids and comets would have played a significant role in the evolution of the martian atmosphere, not only by causing atmospheric erosion but also by delivering material and volatiles to the planet. We investigate the atmospheric loss and the delivery of volatiles with an analytical model that takes into account the impact simulation results and the flux of impactors given in the literature. The atmospheric loss and the delivery of volatiles are calculated to obtain the atmospheric pressure evolution. Our results suggest that the impacts alone cannot satisfactorily explain the loss of significant atmospheric mass since the Late Noachian (approximately 3.7-4 Ga). A period with intense bombardment of meteorites could have increased the atmospheric loss; but to explain the loss of a speculative massive atmosphere in the Late Noachian, other factors of atmospheric erosion and replenishment also need to be taken into account.

  8. Searching for Amino Acids in Meteorites and Comet Samples

    Science.gov (United States)

    Cook, Jamie Elsila

    2010-01-01

    Chemistry plays an important role in the interdisciplinary field of astrobiology, which strives to understand the origin, distribution, and evolution of life throughout the universe. Chemical techniques are used to search for and characterize the basic ingredients for life, from the elements through simple molecules and up to the more complex compounds that may serve as the ingredients for life. The Astrobiology Analytical Laboratory at NASA Goddard uses state-of-the-art laboratory analytical instrumentation in unconventional ways to examine extraterrestrial materials and tackle some of the big questions in astrobiology. This talk will discuss some of the instrumentation and techniques used for these unique samples, as well as some of our most interesting results. The talk will present two areas of particular interest in our laboratory: (1) the search for chiral excesses in meteoritic amino acids, which may help to explain the origin of homochirality in life on Earth; and (2) the detection of amino acids and amines in material returned by NASA's Stardust mission, which rendevouzed with a cornet and brought back cometary particles to the Earth.

  9. Evidence From Hydrogen Isotopes in Meteorites for a Martian Permafrost

    Science.gov (United States)

    Usui, T.; Alexander, C. M. O'D.; Wang, J.; Simon, J. I.; Jones, J. H.

    2014-01-01

    Fluvial landforms on Mars suggest that it was once warm enough to maintain persistent liquid water on its surface. The transition to the present cold and dry Mars is closely linked to the history of surface water, yet the evolution of surficial water is poorly constrained. We have investigated the evolution of surface water/ ice and its interaction with the atmosphere by measurements of hydrogen isotope ratios (D/H: deuterium/ hydrogen) of martian meteorites. Hydrogen is a major component of water (H2O) and its isotopes fractionate significantly during hydrological cycling between the atmosphere, surface waters, ground ice, and polar cap ice. Based on in situ ion microprobe analyses of three geochemically different shergottites, we reported that there is a water/ice reservoir with an intermediate D/H ratio (delta D = 1,000?2500 %) on Mars. Here we present the possibility that this water/ice reservoir represents a ground-ice/permafrost that has existed relatively intact over geologic time.

  10. Analysis of magnetic compounds of Kosice meteorite using Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Dekan, J.; Sitek, J.; Sedlackova, K.

    2013-01-01

    Meteorite fall was observed by the town Kosice in Slovakia in February 2010. The fall itself was imaged by three security video cameras from Hungary. Detailed bolide light curves were obtained through clouds by radiometers on seven cameras of the European Fireball Network. Records of sonic waves were found on six seismic and four infrasonic stations. chondrites in various works. Due to the high abundance of iron in the solar system and its chemical and physical properties, we can gain insight into the formation and evolution of planets through the study of iron compounds in the planetary bodies. These kinds of analyses can bring important knowledge about phases and compounds formed in extraterrestrial conditions, which have another features than their terrestrial analogues. The "5"7Fe Moessbauer spectroscopy is one of the most sensitive methods for such studies. In this work Moessbauer spectroscopy will be used for phase analysis of iron bearing compounds with the aim to identify magnetic fractions using magnetic separation. (authors)

  11. A Meteorite Dropping Superbolide from the Catastrophycally Disrupted Comet C1919Q2 Metcalf: A Pathway for Meteorites from Jupiter Family Comets

    Science.gov (United States)

    Trigo-Rodríguez, J. M.; Madiedo, J. M.; Williams, I. P.; Castro-Tirado, A. J.; Llorca, J.; Vítek, S.; Jelínek, M.

    2009-03-01

    A meter-sized meteoroid probably produced during the disintegration of comet C1919Q2 Metcalf was observed producing a -18 magn. bolide (MNRAS, in press).The progenitor meteoroid was sufficiently large and of high enough tensile strength to produce meteorites.

  12. Parenting Seminars for Divorcing Parents.

    Science.gov (United States)

    Frieman, Barry B.

    1995-01-01

    Profiles the parenting seminars and counseling services for divorcing parents offered by the Children of Separation and Divorce Center, a community service agency in Maryland. The seminars are designed to help parents adjust to divorce and understand the needs of their children during and after the divorce process. (MDM)

  13. The parent magma of xenoliths in shergottite EETA79001: Bulk and trace element composition inferred from magmatic inclusions

    Science.gov (United States)

    Treiman, Allan H.; Lindstrom, David J.; Martinez, Rene R.

    1994-01-01

    The SNC meteorites are samples of the Martian crust, so inferences about their origins and parent magmas are of wide planetologic significance. The EETA79001 shergottite, a basalt, contains xenoliths of pyroxene-olivine cumulate rocks which are possibly related to the ALHA77005 and LEW88516 SNC lherzolites. Olivines in the xenoliths contain magmatic inclusions, relics of magma trapped within the growing crystals. The magmatic inclusions allow a parent magma composition to be retrieved; it is similar to the composition reconstructed from xenolith pyroxenes by element distribution coefficients. The xenolith parent magma is similar but not identical to parent magmas for the shergottite lherzolites.

  14. Ernst Florens Friedrich Chladni (1756-1827) and the origins of modern meteorite research

    Science.gov (United States)

    Marvin, Ursula B.

    1996-09-01

    inaugurated internationally—although opposition lingered on until 1803 April, when nearly 3,000 stones fell at L'Aigle in Normandy and transformed the last skeptics into believers. Chladni immediately received full credit for his hypothesis of falls, but decades passed before his linking of falling bodies with fireballs received general acceptance. His hypothesis of their origin met with strong resistance from those who argued that stones formed within the Earth's atmosphere or were ejected by lunar volcanoes. After 1860, when both of these hypotheses were abandoned, there followed a century of debate between proponents of an interstellar vs. a planetary origin. Not until the 1950s did conclusive evidence of their elliptical orbits establish meteorite parent bodies as members of the solar system. Thus, nearly 200 years passed before the questions of origin that Chladni raised finally were resolved.

  15. Highly 15N-Enriched Chondritic Clasts in the Isheyevo Meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Bonal, L; Huss, G R; Krot, A N; Nagashima, K; Ishii, H A; Bradley, J P; Hutcheon, I D

    2009-01-14

    The metal-rich carbonaceous chondrites (CB and CH) have the highest whole-rock {sup 15}N enrichment ({delta}{sup 15}N up to +1500{per_thousand}), similar to {delta}{sup 15}N values reported in micron-sized regions (hotspots) of Interplanetary Dust Particles (IDPs) of possibly cometary origin and fine-grained matrices of unmetamorphosed chondrites. These {sup 15}N-rich hotspots are commonly attributed to low-temperature ion-molecule reactions in the protosolar molecular cloud or in the outer part of the protoplanetary disk. The nature of the whole-rock {sup 15}N enrichment of the metal-rich chondrites is not understood. We report a discovery of a unique type of primitive chondritic clasts in the CH/CB-like meteorite Isheyevo, which provides important constraints on the origin of {sup 15}N anomaly in metal-rich chondrites and nitrogen-isotope fractionation in the Solar System. These clasts contain tiny chondrules and refractory inclusions (5-15 {micro}m in size), and abundant ferromagnesian chondrule fragments (1-50 {micro}m in size) embedded in the partly hydrated, fine-grained matrix material composed of olivines, pyroxenes, poorly-organized aromatic organics, phyllosilicates and other hydrous phases. The mineralogy and oxygen isotope compositions of chondrules and refractory inclusions in the clasts are similar to those in the Isheyevo host, suggesting formation at similar heliocentric distances. In contrast to the previously known extraterrestrial samples, the fine-grained material in the clasts is highly and rather uniformly enriched in {sup 15}N, with bulk {delta}{sup 15}N values ranging between +1000 and +1300{per_thousand}; the {delta}{sup 15}N values in rare hotspots range from +1400 to +4000{per_thousand}. Since fine-grained matrices in the lithic clasts are the only component containing thermally unprocessed (during CAI and chondrule formation or during impact melting) materials that accreted into the metal rich chondrite parent body(ies), the {sup 15}N

  16. 2-cm versus 4-cm surgical excision margins for primary cutaneous melanoma thicker than 2 mm: a randomised, multicentre trial

    DEFF Research Database (Denmark)

    Gillgren, Peter; Drzewiecki, Krzysztof T; Niin, Marianne

    2011-01-01

    Optimum surgical resection margins for patients with clinical stage IIA-C cutaneous melanoma thicker than 2 mm are controversial. The aim of the study was to test whether survival was different for a wide local excision margin of 2 cm compared with a 4-cm excision margin....

  17. Multiple and fast: The accretion of ordinary chondrite parent bodies

    International Nuclear Information System (INIS)

    Vernazza, P.; Barge, P.; Zanda, B.; Hewins, R.; Binzel, R. P.; DeMeo, F. E.; Lockhart, M.; Hiroi, T.; Birlan, M.; Ricci, L.

    2014-01-01

    Although petrologic, chemical, and isotopic studies of ordinary chondrites and meteorites in general have largely helped establish a chronology of the earliest events of planetesimal formation and their evolution, there are several questions that cannot be resolved via laboratory measurements and/or experiments alone. Here, we propose the rationale for several new constraints on the formation and evolution of ordinary chondrite parent bodies (and, by extension, most planetesimals) from newly available spectral measurements and mineralogical analysis of main-belt S-type asteroids (83 objects) and unequilibrated ordinary chondrite meteorites (53 samples). Based on the latter, we suggest that spectral data may be used to distinguish whether an ordinary chondrite was formed near the surface or in the interior of its parent body. If these constraints are correct, the suggested implications include that: (1) large groups of compositionally similar asteroids are a natural outcome of planetesimal formation and, consequently, meteorites within a given class can originate from multiple parent bodies; (2) the surfaces of large (up to ∼200 km) S-type main-belt asteroids mostly expose the interiors of the primordial bodies, a likely consequence of impacts by small asteroids (D < 10 km) in the early solar system; (3) the duration of accretion of the H chondrite parent bodies was likely short (instantaneous or in less than ∼10 5 yr, but certainly not as long as 1 Myr); (4) LL-like bodies formed closer to the Sun than H-like bodies, a possible consequence of the radial mixing and size sorting of chondrules in the protoplanetary disk prior to accretion.

  18. The radiation age of meteorites; L'age des meteorites; Opredelenie vozrasta meteoritov s pomoshch'yu radiatsii; Edad de los meteoritos

    Energy Technology Data Exchange (ETDEWEB)

    Goebel, K; Schmidlin, P [European Organisation for Nuclear Research, Geneva (Switzerland)

    1962-01-15

    Radioisotopes produced by cosmic radiation in meteorites while travelling through space can be used to trace the history of these meteorites. The radioisotopes and the accumulated daughter-elements in the meteorite must be determined in order to evaluate how long the meteorite was exposed to cosmic radiation. (It must be assumed for this calculation that the flux of the cosmic radiation is constant with time.) Most often gaseous isotopes have been used for these measurements as they can be easily separated from the meteoric substance. In the reported work tritium and argon have been mainly used. From the ratio H{sup 3}/He{sup 3}, radiation ages from a few millions to several hundred millions of years have been found. The recent measurements made at the European Organisation for Nuclear Research (CERN) agree in principle with results from other sources. The probable errors from diffusion-losses of gas and the influence of shielding in the pre-atmospheric meteorite are discussed in the paper. By taking into consideration the measured cross-section for tritium production in the elements which form the meteorite, the values of the cosmic-ray flux in outer space can be determined. (author) [French] Les radioisotopes produits par les rayonnements cosmiques dans les meteorites circulant dans l'espace peuvent servir a reconstituer l'histoire de ces corps. Il faut mesurer les radioisotopes et les produits de filiation accumules dans la meteorite pour evaluer le temps pendant lequel la meteorite a ete exposee aux rayonnements cosmiques. (On considere alors que le flux des rayonnements cosmiques ne varie pas dans le temps.) Pour ces mesures, on se fonde le plus souvent sur les isotopes gazeux parce qu'il est facile de les separer de la substance meteorique. Dans les recherches qui font l'objet du present memoire, il s'agissait surtout du tritium et de l'argon. En partant du rapport {sup 3}H/{sup 3}He, on a pu evaluer des ages allant de quelques millions a plusieurs centaines

  19. Stress calculations for RTNS-iI 50-cm targets

    International Nuclear Information System (INIS)

    Schumacher, B.J.; House, P.A.

    1981-04-01

    Structural calculations made during design of a 50-cm target for the Rotating Target Neutron Source (RTNS-II) are detailed. The limited ability of the current 23-cm diameter target to dissipate the additional beam power required for a yield increase from 2 x 10 13 to 4 x 10 13 neutrons/second has resulted in the need for a larger target. The stresses of several design configurations for a 50-cm target were calculated. The stress contours that would occur in several different target designs with and without various types of structural reinforcement that reduce stress and deflection are presented

  20. Uncertainty Analysis of Consequence Management (CM) Data Products.

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, Brian D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eckert-Gallup, Aubrey Celia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cochran, Lainy Dromgoole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kraus, Terrence D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fournier, Sean Donovan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allen, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schetnan, Richard Reed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Simpson, Matthew D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Okada, Colin E. [Remote Sensing Lab. (RSL), Nellis AFB, Las Vegas, NV (United States); Bingham, Avery A. [Remote Sensing Lab. (RSL), Nellis AFB, Las Vegas, NV (United States)

    2018-01-01

    The goal of this project is to develop and execute methods for characterizing uncertainty in data products that are deve loped and distributed by the DOE Consequence Management (CM) Program. A global approach to this problem is necessary because multiple sources of error and uncertainty from across the CM skill sets contribute to the ultimate p roduction of CM data products. This report presents the methods used to develop a probabilistic framework to characterize this uncertainty and provides results for an uncertainty analysis for a study scenario analyzed using this framework.

  1. Biomarkers and Microfossils in the Murchison, Rainbow, and Tagish Lake meteorites

    Science.gov (United States)

    Hoover, Richard B.; Jerman, Gregory A.; Rozanov, Alexei Y.; Davies, Paul C.

    2003-02-01

    During the past six years, we have conducted extensive scanning electron and optical microscopy investigations and x-ray analysis to determine the morphology, life cycle processes, and elemental distributions in living and fossil cyanobacteria, bacteria, archaea, fungi, and algae sampled from terrestrial environments relevant to Astrobiology. Biominerals, pseudomorphs and microfossils have been studied for diverse microbial groups in various states of preservation in many types of rocks (e.g., oil shales, graphites, shungites, bauxites, limestones, pyrites, phosphorites, and hydrothermal vent chimneys). Results of these studies have been applied to the search for biosignatures in carbonaceous chondrites, stony, and nickel iron meteorites. We review important biomarkers found in terrestrial rocks and meteorites and present additional evidence for the existence of indigenous bacterial microfossils in-situ in freshly fractured surfaces of the Murchison, Rainbow and Tagish Lake carbonaceous meteorites. We provide secondary and backscatter electron images and spectral data obtained with Field Emission and Environmental Scanning Electron Microscopes of biominerals and microfossils. We discuss techniques for discriminating indigenous microfossils from recent terrestrial contaminants. Images are provided of framboidal magnetites in oil shales and meteorites and images and 2D x-ray maps are shown of bacterial microfossils embedded in the mineral matrix of the Murchison, Rainbow and Tagish Lake Carbonaceous Meteorites. These microfossils exhibit characteristics that preclude their interpretation as post-arrival contaminants and we interpret them as indigenous biogenic remains.

  2. The fall of a meteorite at Aegos Potami in 467/6 BC

    Science.gov (United States)

    Theodossiou, E. Th; Niarchos, P. G.; Manimanis, V. N.; Orchiston, W.

    2002-12-01

    Cosmic catastrophes have been associated from time to time with the fall of celestial objects to Earth. From the writings of ancient Greek authors we know that during the second year of the 78th Olympiad, that is the year corresponding to 467/6 BC, a very large meteorite fell at Aegos Potami, in the Gallipoli Peninsula (in Eastern Thrace). This event was predicted by Anaxagoras, and the meteorite was worshipped by the Cherronesites until at least the first Century AD. The fall of the Aegos Potami Meteorite was not associated with any cosmic catastrophe, but it was believed to have foretold the terminal defeat of the Athenians by the Spartans in 405 BC near Aegos Potami, which brought to an end the Peloponnesian War in favour of Sparta. In addition, according to the Latin author Pliny the Elder, during the first century AD the inhabitants of Avydus in Asia Minor worshipped another meteorite that was displayed in the city's sports centre, The fall of this meteorite is also said to have been predicted by Anaxagoras.

  3. CM Process Improvement and the International Space Station Program (ISSP)

    Science.gov (United States)

    Stephenson, Ginny

    2007-01-01

    This viewgraph presentation reviews the Configuration Management (CM) process improvements planned and undertaken for the International Space Station Program (ISSP). It reviews the 2004 findings and recommendations and the progress towards their implementation.

  4. One-cm-thick Si detector at LHe temperature

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, 44100 Ferrara (Italy)], E-mail: braggio@pd.infn.it; Bressi, G. [INFN, Sez. di Pavia, Via Bassi 6, 27100 Pavia (Italy); Carugno, G. [INFN, Sez. di Padova, Via Marzolo 8, 35131 Padova (Italy); Galeazzi, G. [Laboratori Nazionali di Legnaro, Via dell' Universita 1, 35020 Legnaro (Italy); Serafin, A. [Dipartimento di Fisica, Universita di Padova, Via Marzolo 8, 35131 Padova (Italy)

    2007-10-11

    A silicon p-i-n diode of thickness 1 cm has been studied experimentally at liquid helium temperature. This preliminary study is aimed at the construction of a much bigger detector to detect low energy neutrino events.

  5. One-cm-thick Si detector at LHe temperature

    International Nuclear Information System (INIS)

    Braggio, C.; Bressi, G.; Carugno, G.; Galeazzi, G.; Serafin, A.

    2007-01-01

    A silicon p-i-n diode of thickness 1 cm has been studied experimentally at liquid helium temperature. This preliminary study is aimed at the construction of a much bigger detector to detect low energy neutrino events

  6. The 21-cm Signal from the cosmological epoch of recombination

    Energy Technology Data Exchange (ETDEWEB)

    Fialkov, A. [Departement de Physique, Ecole Normale Superieure, CNRS, 24 rue Lhomond, Paris, 75005 (France); Loeb, A., E-mail: anastasia.fialkov@phys.ens.fr, E-mail: aloeb@cfa.harvard.edu [Department of Astronomy, Harvard University, 60 Garden Street, MS-51, Cambridge, MA, 02138 (United States)

    2013-11-01

    The redshifted 21-cm emission by neutral hydrogen offers a unique tool for mapping structure formation in the early universe in three dimensions. Here we provide the first detailed calculation of the 21-cm emission signal during and after the epoch of hydrogen recombination in the redshift range of z ∼ 500–1,100, corresponding to observed wavelengths of 100–230 meters. The 21-cm line deviates from thermal equilibrium with the cosmic microwave background (CMB) due to the excess Lyα radiation from hydrogen and helium recombinations. The resulting 21-cm signal reaches a brightness temperature of a milli-Kelvin, orders of magnitude larger than previously estimated. Its detection by a future lunar or space-based observatory could improve dramatically the statistical constraints on the cosmological initial conditions compared to existing two-dimensional maps of the CMB anisotropies.

  7. The 21-cm Signal from the cosmological epoch of recombination

    International Nuclear Information System (INIS)

    Fialkov, A.; Loeb, A.

    2013-01-01

    The redshifted 21-cm emission by neutral hydrogen offers a unique tool for mapping structure formation in the early universe in three dimensions. Here we provide the first detailed calculation of the 21-cm emission signal during and after the epoch of hydrogen recombination in the redshift range of z ∼ 500–1,100, corresponding to observed wavelengths of 100–230 meters. The 21-cm line deviates from thermal equilibrium with the cosmic microwave background (CMB) due to the excess Lyα radiation from hydrogen and helium recombinations. The resulting 21-cm signal reaches a brightness temperature of a milli-Kelvin, orders of magnitude larger than previously estimated. Its detection by a future lunar or space-based observatory could improve dramatically the statistical constraints on the cosmological initial conditions compared to existing two-dimensional maps of the CMB anisotropies

  8. Statistical 21-cm Signal Separation via Gaussian Process Regression Analysis

    Science.gov (United States)

    Mertens, F. G.; Ghosh, A.; Koopmans, L. V. E.

    2018-05-01

    Detecting and characterizing the Epoch of Reionization and Cosmic Dawn via the redshifted 21-cm hyperfine line of neutral hydrogen will revolutionize the study of the formation of the first stars, galaxies, black holes and intergalactic gas in the infant Universe. The wealth of information encoded in this signal is, however, buried under foregrounds that are many orders of magnitude brighter. These must be removed accurately and precisely in order to reveal the feeble 21-cm signal. This requires not only the modeling of the Galactic and extra-galactic emission, but also of the often stochastic residuals due to imperfect calibration of the data caused by ionospheric and instrumental distortions. To stochastically model these effects, we introduce a new method based on `Gaussian Process Regression' (GPR) which is able to statistically separate the 21-cm signal from most of the foregrounds and other contaminants. Using simulated LOFAR-EoR data that include strong instrumental mode-mixing, we show that this method is capable of recovering the 21-cm signal power spectrum across the entire range k = 0.07 - 0.3 {h cMpc^{-1}}. The GPR method is most optimal, having minimal and controllable impact on the 21-cm signal, when the foregrounds are correlated on frequency scales ≳ 3 MHz and the rms of the signal has σ21cm ≳ 0.1 σnoise. This signal separation improves the 21-cm power-spectrum sensitivity by a factor ≳ 3 compared to foreground avoidance strategies and enables the sensitivity of current and future 21-cm instruments such as the Square Kilometre Array to be fully exploited.

  9. [Parenting styles].

    Science.gov (United States)

    Torío López, Susana; Peña Calvo, José Vicente; Inda Caro, Mercedes

    2008-02-01

    Parental educational styles constitute one of the key elements of family socialization. The aim of the present essay is to present the results of a research project carried out in the Principality of Asturias (Spain) among 2,965 families with children of infant and primary-school age (5-8 years old). This research attempts to analyse, among other aspects, parental behaviour tendencies in child upbringing. The analysis of the results obtained allows us to: 1) identify the most common attitudinal and behavioural tendencies of parents in the upbringing of their children; 2) determine how many people have a well defined parental style, and delimit their socio-educational characteristics. Lastly, we consider the need to change some parental behaviour patterns and stress the importance of family education programmes, with the aim of promoting appropriate parenting models and modifying or improving current practices.

  10. Adoptive parenting.

    Science.gov (United States)

    Grotevant, Harold D; Lo, Albert Yh

    2017-06-01

    Challenges in adoptive parenting continue to emerge as adoption policies and practices evolve. We review three areas of research in adoptive parenting that reflect contemporary shifts in adoption. First, we highlight recent findings concerning openness in adoption contact arrangements, or contact between a child's families of birth and rearing. Second, we examine research regarding racial and cultural socialization in transracial and international adoptions. Finally, we review investigations of parenting experiences of lesbian and gay adoptive parents. Overall, parenting processes (e.g., supportive vs. problematic family interaction) are better predictors of child adjustment than are group differences (e.g., open vs. closed adoptions; adoption by heterosexual vs. same-sex parents). The distinctive needs of adopted children call for preparation of adoption-competent mental health, casework, education, and health care professionals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Peripartum Morbidity after Cesarean Delivery for Arrest of Dilation at 4 to 5 cm Compared with 6 to 10 cm.

    Science.gov (United States)

    Dahlke, Joshua D; Sperling, Jeffrey D; Has, Phinnara; Lovgren, Todd R; Connealy, Brendan D; Rouse, Dwight J

    2018-04-24

     Given that recent consensus guidelines established to decrease cesarean delivery (CD) rates use 6 cm to define the onset of the active phase of labor, our objective was to evaluate maternal and neonatal outcomes after CD for the indication of arrest of dilation at 4 to 5 cm compared with ≥ 6 cm.  We performed a secondary analysis using data from the Maternal Fetal-Medicine Units Network Cesarean Registry. We included nulliparous women with term, singleton, vertex gestations who underwent primary CD for arrest of dilation. We compared those who reached a maximum cervical dilation of 4 to 5 cm with those of ≥6 cm. Our primary outcome was composite maternal morbidity that included chorioamnionitis, endometritis, transfusion, wound complication, operative injury, intensive care unit admission, or death.  Of the 73,257 women in the dataset, 5,681 met the inclusion criteria. After adjusting for confounders, there was no difference in composite maternal (adjusted odds ratio [aOR]: 1.19; 95% confidence interval [CI]: 0.94-1.52) or neonatal morbidity (aOR: 0.94; 95% CI: 0.79-1.10) between the groups.  In this historical cohort, maternal and neonatal outcomes after CD for arrest of dilation ≥ 6 cm were comparable to those performed at 4 to 5 cm and support recent labor management guidelines. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  12. Leveraging the NLM map from SNOMED CT to ICD-10-CM to facilitate adoption of ICD-10-CM.

    Science.gov (United States)

    Cartagena, F Phil; Schaeffer, Molly; Rifai, Dorothy; Doroshenko, Victoria; Goldberg, Howard S

    2015-05-01

    Develop and test web services to retrieve and identify the most precise ICD-10-CM code(s) for a given clinical encounter. Facilitate creation of user interfaces that 1) provide an initial shortlist of candidate codes, ideally visible on a single screen; and 2) enable code refinement. To satisfy our high-level use cases, the analysis and design process involved reviewing available maps and crosswalks, designing the rule adjudication framework, determining necessary metadata, retrieving related codes, and iteratively improving the code refinement algorithm. The Partners ICD-10-CM Search and Mapping Services (PI-10 Services) are SOAP web services written using Microsoft's.NET 4.0 Framework, Windows Communications Framework, and SQL Server 2012. The services cover 96% of the Partners problem list subset of SNOMED CT codes that map to ICD-10-CM codes and can return up to 76% of the 69,823 billable ICD-10-CM codes prior to creation of custom mapping rules. We consider ways to increase 1) the coverage ratio of the Partners problem list subset of SNOMED CT codes and 2) the upper bound of returnable ICD-10-CM codes by creating custom mapping rules. Future work will investigate the utility of the transitive closure of SNOMED CT codes and other methods to assist in custom rule creation and, ultimately, to provide more complete coverage of ICD-10-CM codes. ICD-10-CM will be easier for clinicians to manage if applications display short lists of candidate codes from which clinicians can subsequently select a code for further refinement. The PI-10 Services support ICD-10 migration by implementing this paradigm and enabling users to consistently and accurately find the best ICD-10-CM code(s) without translation from ICD-9-CM. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Parental Bonding

    Directory of Open Access Journals (Sweden)

    T. Paul de Cock

    2014-08-01

    Full Text Available Estimating the early parent–child bonding relationship can be valuable in research and practice. Retrospective dimensional measures of parental bonding provide a means for assessing the experience of the early parent–child relationship. However, combinations of dimensional scores may provide information that is not readily captured with a dimensional approach. This study was designed to assess the presence of homogeneous groups in the population with similar profiles on parental bonding dimensions. Using a short version of the Parental Bonding Instrument (PBI, three parental bonding dimensions (care, authoritarianism, and overprotection were used to assess the presence of unobserved groups in the population using latent profile analysis. The class solutions were regressed on 23 covariates (demographics, parental psychopathology, loss events, and childhood contextual factors to assess the validity of the class solution. The results indicated four distinct profiles of parental bonding for fathers as well as mothers. Parental bonding profiles were significantly associated with a broad range of covariates. This person-centered approach to parental bonding has broad utility in future research which takes into account the effect of parent–child bonding, especially with regard to “affectionless control” style parenting.

  14. The cali meteorite fell: A new H/L ordinary chondrite

    Science.gov (United States)

    Rodriguez, J.M.T.; Llorca, J.; Rubin, A.E.; Grossman, J.N.; Sears, D.W.G.; Naranjo, M.; Bretzius, S.; Tapia, M.; Sepulveda, M.H.G.

    2009-01-01

    The fall of the Cali meteorite took place on 6 July 2007 at 16 h 32 ?? 1 min local time (21 h 32 ?? 1 min UTC). A daylight fireball was witnessed by hundreds of people in the Cauca Valley in Colombia from which 10 meteorite samples with a total mass of 478 g were recovered near 3??24.3'N, 76??30.6'W. The fireball trajectory and radiant have been reconstructed with moderate accuracy. From the computed radiant and from considering various plausible velocities, we obtained a range of orbital solutions that suggest that the Cali progenitor meteoroid probably originated in the main asteroid belt. Based on petrography, mineral chemistry, magnetic susceptibility, fhermoluminescence, and bulk chemistry, the Cali meteorite is classified as an H/L4 ordinary chondrite breccia.

  15. The distribution of chiral asymmetry in meteorites: An investigation using asymmetric autocatalytic chiral sensors

    Science.gov (United States)

    Kawasaki, Tsuneomi; Hatase, Kunihiko; Fujii, Yusuke; Jo, Kazumichi; Soai, Kenso; Pizzarello, Sandra

    2006-11-01

    We separated and analyzed several organic and inorganic phases of the carbonaceous chondrite matrix to determine whether they contained any inherent asymmetry. Our intent was to determine any possible foci of asymmetry besides the one determined for meteoritic amino acids. As a probe, we employed a very sensitive asymmetric autocatalytic reaction. We were able to determine that asymmetry still resides in powders after extraction with water and solvents as well as in the insoluble organic material (IOM) obtained after demineralization. Asymmetry is not found any longer in the IOM after hydrothermal treatment and in meteorite powders from which all organics had been removed by O 2 plasma at low temperature. The data are interpreted to indicate a diverse molecular asymmetry residing in yet unknown meteorite organics; these organics might have had an inductive effect on organic molecular evolution upon exogenous delivery to the early Earth.

  16. The Innisfree meteorite: Dynamical history of the orbit - Possible family of meteor bodies

    Science.gov (United States)

    Galibina, I. V.; Terent'eva, A. K.

    1987-09-01

    Evolution of the Innisfree meteorite orbit caused by secular perturbations is studied over the time interval of 500000 yrs (from the current epoch backwards). Calculations are made by the Gauss-Halphen-Gorjatschew method taking into account perturbations from the four outer planets - Jupiter, Saturn, Uranus and Neptune. In the above mentioned time interval the meteorite orbit has undergone no essential transformations. The Innisfree orbit intersected in 91 cases the Earth orbit and in 94 - the Mars orbit. A system of small and large meteor bodies (producing ordinary meteors and fireballs) which may be genetically related to the Innisfree meteorite has been found, i.e. there probably exists an Innisfree family of meteor bodies.

  17. Which fireballs are meteorites - A study of the Prairie Network photographic meteor data

    Science.gov (United States)

    Wetherill, G. W.; Revelle, D. O.

    1981-11-01

    With the exception of three recovered meteorites with photographic fireball data (Pribram, Lost City, Innisfree), there is generally little information regarding the location of meteorites in the solar system prior to their impact on the earth. An investigation is conducted with the objective to identify those fireballs (bright meteor) data from the Prairie Network. The investigation is based on the belief that many small ordinary chondrites must be present among the photographed bright fireballs. Observations of the recovered fireballs are used to identify characteristics of their dynamics while passing through the atmosphere. In this way criteria are established for identifying those fireballs with similar dynamical characteristics. On the basis of the studies, a catalog is provided of fireballs which have a high probability of being ordinary chondrites or other strong meteorites.

  18. Element distribution and noble gas isotopic abundances in lunar meteorite Allan Hills A81005

    International Nuclear Information System (INIS)

    Kraehenbuehl, U.; Eugster, O.; Niedermann, S.

    1986-01-01

    Antarctic meteorite ALLAN HILLS A81005, an anorthositic breccia, is recognized to be of lunar origin. The noble gases in this meteorite were analyzed and found to be solar-wind implanted gases, whose absolute and relative concentrations are quite similar to those in lunar regolith samples. A sample of this meteorite was obtained for the analysis of the noble gas isotopes, including Kr(81), and for the determination of the elemental abundances. In order to better determine the volume derived from the surface correlated gases, grain size fractions were prepared. The results of the instrumental measurements of the gamma radiation are listed. From the amounts of cosmic ray produced noble gases and respective production rates, the lunar surface residence times were calculated. It was concluded that the lunar surface time is about half a billion years

  19. Analysis of Košice Meteorite by Mössbauer Spectroscopy

    Science.gov (United States)

    Sitek, Jozef; Dekan, Július; Sedlačková, Katarína

    2016-07-01

    The 57Fe Mössbauer spectroscopy method was used to investigate iron-containing compounds in town Košice meteorite fallen on the territory of Slovakia in February 2010. The results showed that the Mössbauer spectra consisted of magnetic and non-magnetic components related to different iron-bearing phases. The non-magnetic phase includes olivine, pyroxene and traces of Fe3+ phase and the magnetic component comprises troilite (FeS) and iron-rich Fe-Ni alloy with hyperfine magnetic field typical for kamacite. Samples from meteorite were obtained in powder from different depths to inspect its heterogeneous composition. The content of kamacite increases to the detriment of troilite from the surface toward the centre of the sample. Measurements at liquid nitrogen temperature confirmed phase composition of investigated meteorite. Main constituent elements of studied samples were also determined by X-ray fluorescence analysis.

  20. Low γ activity measurement of meteorites using HPGe–NaI detector system

    Energy Technology Data Exchange (ETDEWEB)

    Colombetti, P. [Dipartimento di Fisica dell' Università di Torino (Italy); Osservatorio Astrofisico di Torino – INAF, Torino (Italy); Taricco, C., E-mail: carla.taricco@unito.it [Dipartimento di Fisica dell' Università di Torino (Italy); Osservatorio Astrofisico di Torino – INAF, Torino (Italy); Bhandari, N. [Basic Sciences Research Institute, Navrangpura, Ahmedabad (India); Sinha, N. [Department of Science, Wentworth Institute of Technology, Boston (United States); Di Martino, M.; Cora, A. [Osservatorio Astrofisico di Torino – INAF, Torino (Italy); Vivaldo, G. [Dipartimento di Fisica dell' Università di Torino (Italy)

    2013-08-01

    The radioactivity in natural samples like cosmogenic isotopes in meteorites, in Moon samples, in earth and ice in Antarctica, produced by protons, neutrons, μ mesons and other charged particles, is very low, usually below 0.001 disintegration per minute per gram. Therefore, very special techniques are required, particularly if the sample cannot be destroyed for chemical separation and system must have possibility of counting large amount of sample. For this purpose we have developed a highly selective Ge–NaI coincidence spectrometer, operating in the underground Laboratory of Monte dei Cappuccini (INAF) in Torino. We have then improved it by developing a multiparametric acquisition system, which allows better selectivity of the coincidence windows (e.g., in meteorites, to disentangle cosmogenic {sup 44}Ti signal from overlapping {sup 214}Bi, originated by naturally occurring {sup 238}U). Applications of this system to the study of meteorites (chondrite, achondrite and iron samples) are described.

  1. Tungsten isotopes in bulk meteorites and their inclusions-Implications for processing of presolar components in the solar protoplanetary disk

    DEFF Research Database (Denmark)

    Holst, Jesper Christian; Paton, Chad; Wielandt, Daniel Kim Peel

    2015-01-01

    We present high precision, low- and high-resolution tungsten isotope measurements of iron meteorites Cape York (IIIAB), Rhine Villa (IIIE), Bendego (IC), and the IVB iron meteorites Tlacotepec, Skookum, and Weaver Mountains, as well as CI chondrite Ivuna, a CV3 chondrite refractory inclusion (CAI...

  2. The statistical model calculation of prompt neutron spectra from spontaneous fission of {sup 244}Cm and {sup 246}Cm

    Energy Technology Data Exchange (ETDEWEB)

    Gerasimenko, B.F. [V.G. Khlopin Radium Inst., Saint Peterburg (Russian Federation)

    1997-03-01

    The calculations of integral spectra of prompt neutrons of spontaneous fission of {sup 244}Cm and {sup 246}Cm were carried out. The calculations were done by the Statistical Computer Code Complex SCOFIN applying the Hauser-Feschbach method as applied to the description of the de-excitation of excited fission fragments by means of neutron emission. The emission of dipole gamma-quanta from these fragments was considered as a competing process. The average excitation energy of a fragment was calculated by two-spheroidal model of tangent fragments. The density of levels in an excited fragment was calculated by the Fermi-gas model. The quite satisfactory agreement was reached between theoretical and experimental results obtained in frames of Project measurements. The calculated values of average multiplicities of neutron number were 2,746 for {sup 244}Cm and 2,927 for {sup 246}Cm that was in a good accordance with published experimental figures. (author)

  3. Nanoindenting the Chelyabinsk Meteorite to Learn about Impact Deflection Effects in asteroids

    Energy Technology Data Exchange (ETDEWEB)

    Moyano-Cambero, Carles E.; Trigo-Rodríguez, Josep M.; Martínez-Jiménez, Marina; Lloro, Ivan [Institute of Space Sciences (IEEC-CSIC), Meteorites, Minor Bodies and Planetary Sciences Group, Campus UAB Bellaterra, c/Can Magrans s/n, 08193 Cerdanyola del Vallès (Barcelona) (Spain); Pellicer, Eva [Departament de Física, Universitat Autónoma de Barcelona, E-08193 Bellaterra (Spain); Williams, Iwan P. [School of Physics and Astronomy, Queen Mary, University of London, 317 Mile End Road, E1 4NS London (United Kingdom); Blum, Jürgen [Institut für Geophysik und extraterrestrische Physik, Technische Universität Braunschweig, Mendelssohnstr. 3, D-38106 Braunschweig (Germany); Michel, Patrick [Lagrange Laboratory, University of Nice, CNRS, Côte d’Azur Observatory (France); Küppers, Michael [European Space Agency, European Space Astronomy Centre, P.O. Box 78, Villanueva de la Cañada E-28691 (Spain); Sort, Jordi, E-mail: moyano@ice.csic.es, E-mail: trigo@ice.csic.es [Institució Catalana de Recerca i Estudis Avançats (ICREA) and Departament de Física, Universitat Autónoma de Barcelona, E-08193 Bellaterra (Spain)

    2017-02-01

    The Chelyabinsk meteorite is a highly shocked, low porosity, ordinary chondrite, probably similar to S- or Q-type asteroids. Therefore, nanoindentation experiments on this meteorite allow us to obtain key data to understand the physical properties of near-Earth asteroids. Tests at different length scales provide information about the local mechanical properties of the minerals forming this meteorite: reduced Young’s modulus, hardness, elastic recovery, and fracture toughness. Those tests are also useful to understand the potential to deflect threatening asteroids using a kinetic projectile. We found that the differences in mechanical properties between regions of the meteorite, which increase or reduce the efficiency of impacts, are not a result of compositional differences. A low mean particle size, attributed to repetitive shock, can increase hardness, while low porosity promotes a higher momentum multiplication. Momentum multiplication is the ratio between the change in momentum of a target due to an impact, and the momentum of the projectile, and therefore, higher values imply more efficient impacts. In the Chelyabinsk meteorite, the properties of the light-colored lithology materials facilitate obtaining higher momentum multiplication values, compared to the other regions described for this meteorite. Also, we found a low value of fracture toughness in the shock-melt veins of Chelyabinsk, which would promote the ejection of material after an impact and therefore increase the momentum multiplication. These results are relevant to the growing interest in missions to test asteroid deflection, such as the recent collaboration between the European Space Agency and NASA, known as the Asteroid Impact and Deflection Assessment mission.

  4. Nanoindenting the Chelyabinsk Meteorite to Learn about Impact Deflection Effects in asteroids

    International Nuclear Information System (INIS)

    Moyano-Cambero, Carles E.; Trigo-Rodríguez, Josep M.; Martínez-Jiménez, Marina; Lloro, Ivan; Pellicer, Eva; Williams, Iwan P.; Blum, Jürgen; Michel, Patrick; Küppers, Michael; Sort, Jordi

    2017-01-01

    The Chelyabinsk meteorite is a highly shocked, low porosity, ordinary chondrite, probably similar to S- or Q-type asteroids. Therefore, nanoindentation experiments on this meteorite allow us to obtain key data to understand the physical properties of near-Earth asteroids. Tests at different length scales provide information about the local mechanical properties of the minerals forming this meteorite: reduced Young’s modulus, hardness, elastic recovery, and fracture toughness. Those tests are also useful to understand the potential to deflect threatening asteroids using a kinetic projectile. We found that the differences in mechanical properties between regions of the meteorite, which increase or reduce the efficiency of impacts, are not a result of compositional differences. A low mean particle size, attributed to repetitive shock, can increase hardness, while low porosity promotes a higher momentum multiplication. Momentum multiplication is the ratio between the change in momentum of a target due to an impact, and the momentum of the projectile, and therefore, higher values imply more efficient impacts. In the Chelyabinsk meteorite, the properties of the light-colored lithology materials facilitate obtaining higher momentum multiplication values, compared to the other regions described for this meteorite. Also, we found a low value of fracture toughness in the shock-melt veins of Chelyabinsk, which would promote the ejection of material after an impact and therefore increase the momentum multiplication. These results are relevant to the growing interest in missions to test asteroid deflection, such as the recent collaboration between the European Space Agency and NASA, known as the Asteroid Impact and Deflection Assessment mission.

  5. Parental divorce and parental death

    DEFF Research Database (Denmark)

    Marcussen, Jette; Thuen, Frode; Poul, Bruun

    2015-01-01

    The aim of this review was to identify research on children and adolescents who experience double bereavement, i.e. the experience of loss through parental divorce followed by either parental death or critical illness with imminent death. This knowledge may identify evidence to underpin knowledge......; challenges in both custodial and non-custodial parental death; risk of mental health problems, and the need of support and interventions....

  6. 35 seasons of US antarctic meteorites (1976-2010) a pictorial guide to the collection

    CERN Document Server

    Righter, Kevin; McCoy, Timothy; Harvey, Ralph; Harvey, Ralph

    2014-01-01

    The US Antarctic meteorite collection exists due to a cooperative program involving the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the Smithsonian Institution.  Since 1976, meteorites have been collected by a NSF-funded field team, shipped for curation, characterization, distribution, and storage at NASA, and classified and stored for long term at the Smithsonian.  It is the largest collection in the world with many significant samples including lunar, martian, many interesting chondrites and achondrites, and even several unusual one-of-

  7. Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites

    OpenAIRE

    Cooper, George; Rios, Andro C.

    2016-01-01

    The majority of biological sugars and their derivatives contain higher abundances of the “d” mirror-image forms relative to the “l” forms. For example, nucleic acids are composed of only d sugars. Carbonaceous meteorites can potentially assist in understanding the long-sought origin of such phenomena; They preserve a record of the earliest (∼4.5 Gy) chemical processes in the Solar System. To date, there have been no systematic studies of d/l (i.e., enantiomer) ratios of meteoritic sugar deriv...

  8. The measurement of the uranium content of crystals, glasses and meteorites with the fission track method

    International Nuclear Information System (INIS)

    Vartanian, R.

    1977-04-01

    In the present investigation, work has been carried out regarding the measurement of the uranium content of minerals, crystals and meteoritic samples from different parts of Iran. In this paper the method of inducing tracks from the 235 U indigenous to the Solid State Nuclear Track Detectors (SSNTDS) is described and new results have been attained. These are summarized as follows: Apatite between (4.16+-0.27) and (10.54+-0.84) ppm, Wulfnite=(4.90+-0.37) ppm, Quartz=(0.15+-0.02) ppm and Meteorite=(0.026+-0.003) ppm. (author)

  9. Superheavy-element fission tracks in iron meteorites, and reply by Bull, R.K

    International Nuclear Information System (INIS)

    Runcorn, S.K.

    1980-01-01

    Comment is made on the lack of superheavy element (SHE) fission tracks observed in silicates from the class IA Odessa iron meteorite by Bull (Nature; 282:393 (1979)). Two explanations are suggested. Firstly, a thermal history for Odessa can be constructed in which the meteorite reaches track retention temperatures only after a time corresponding to many half lives for the SHEs (taken to be approximately 100 Myr) has elapsed and secondly that the IA irons never took up many SHEs. These suggestions are discussed in a reply by Bull. (U.K.)

  10. Backscatter measurements of 11-cm equatorial spread-F irregularities

    International Nuclear Information System (INIS)

    Tsunoda, R.T.

    1980-01-01

    In the equatorial F-region ionosphere, a turbulent cascade process has been found to exist that extends from irregularity spatial wavelengths longer than tens of kilometers down to wavelengths as short as 36 cm. To investigate the small-scale regime of wavelengths less than 36 cm, an equatorial radar experiment was conducted using a frequency of 1320 MHz that corresponds to an irregularity wavelength of 11 cm. The first observations of radar backscatter from 11-cm field-aligned irregularities (FAI) are described. These measurements extend the spatial wavelength regime of F-region FAI to lengths that approach both electron gyroradius and the Debye length. Agreement of these results with the theory of high-frequency drift waves suggests that these observations may be unique to the equatorial ionosphere. That is, the requirement of low electron densities for which the theroy calls may preclude the existence of 11-cm FAI elsewhere in the F-region ionosphere, except in equatorial plasma bubbles

  11. Error Analysis of CM Data Products Sources of Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, Brian D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eckert-Gallup, Aubrey Celia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cochran, Lainy Dromgoole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kraus, Terrence D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allen, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Beal, Bill [National Security Technologies, Joint Base Andrews, MD (United States); Okada, Colin [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States); Simpson, Mathew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-01

    This goal of this project is to address the current inability to assess the overall error and uncertainty of data products developed and distributed by DOE’s Consequence Management (CM) Program. This is a widely recognized shortfall, the resolution of which would provide a great deal of value and defensibility to the analysis results, data products, and the decision making process that follows this work. A global approach to this problem is necessary because multiple sources of error and uncertainty contribute to the ultimate production of CM data products. Therefore, this project will require collaboration with subject matter experts across a wide range of FRMAC skill sets in order to quantify the types of uncertainty that each area of the CM process might contain and to understand how variations in these uncertainty sources contribute to the aggregated uncertainty present in CM data products. The ultimate goal of this project is to quantify the confidence level of CM products to ensure that appropriate public and worker protections decisions are supported by defensible analysis.

  12. Parent Management

    DEFF Research Database (Denmark)

    Knudsen, Hanne

    2007-01-01

    and parents say given these assumptions? Which management responsibility is addressed through such training of the difficult conversation?  My conclusions are, briefly, that the difficult conversation is more correctly to be called an impossible conversation. It is an asking for the parent's consent...

  13. Search for Efficient Foreground Subtraction Method in 21cm Cosmology

    Science.gov (United States)

    Datta, Abhirup; Choudhury, Madhurima; Chakraborty, Arnab

    2017-06-01

    Observations of the HI 21 cm transition line promises to be an important probe into the cosmic Dark Ages and Epoch of Reionization. Detection of this redshifted 21 cm signal is one of the key science goal for several upcoming and future low frequency radio telescopes like Hydrogen Epoch of Reionization Array (HERA), Square Kilometer Array (SKA) and Dark Ages Radio Explorer (DARE). One of the challenges for the detection of this signal is the accuracy of the foreground source removal. Several novel techniques have been explored already to remove bright foregrounds from both interferometric as well as total power experiments. Here, we present preliminary results from our investigation on application of Artificial Neural Networks to detect faint 21cm global signal amidst the sea of bright galactic foreground.

  14. Evolution of the 21 cm signal throughout cosmic history

    International Nuclear Information System (INIS)

    Pritchard, Jonathan R.; Loeb, Abraham

    2008-01-01

    The potential use of the redshifted 21 cm line from neutral hydrogen for probing the epoch of reionization is motivating the construction of several low-frequency interferometers. There is also much interest in the possibility of constraining the initial conditions from inflation and the nature of the dark matter and dark energy by probing the power spectrum of density perturbations in three dimensions and on smaller scales than probed by the microwave background anisotropies. Theoretical understanding of the 21 cm signal has been fragmented into different regimes of physical interest. In this paper, we make the first attempt to describe the full redshift evolution of the 21 cm signal between 0 or approx. 25 before the first galaxies had formed, or to z < or approx. 6 when the residual pockets of hydrogen trace large-scale structure.

  15. CM-2 Environmental/Modal Testing of SPACEHAB Racks

    Science.gov (United States)

    McNelis, Mark E.; Goodnight, Thomas W.

    2001-01-01

    Combined environmental/modal vibration testing has been implemented at the NASA Glenn Research Center's Structural Dynamics Laboratory. The benefits of combined vibration testing are that it facilitates test article modal characterization and vibration qualification testing. The Combustion Module-2 (CM-2) is a space experiment that will launch on shuttle mission STS-107 in the SPACEHAB Research Double Module. The CM-2 flight hardware is integrated into a SPACEHAB single and double rack. CM-2 rack-level combined vibration testing was recently completed on a shaker table to characterize the structure's modal response and verify the random vibration response. Control accelerometers and limit force gauges, located between the fixture and rack interface, were used to verify the input excitation. Results of the testing were used to verify the loads and environments for flight on the shuttles.

  16. Multistage Core Formation in Planetesimals Revealed by Numerical Modeling and Hf-W Chronometry of Iron Meteorites

    Science.gov (United States)

    Neumann, W.; Kruijer, T. S.; Breuer, D.; Kleine, T.

    2018-02-01

    Iron meteorites provide some of the most direct insights into the processes and timescales of core formation in planetesimals. Of these, group IVB irons stand out by having one of the youngest 182Hf-182W model ages for metal segregation (2.9 ± 0.6 Ma after solar system formation), as well as the lowest bulk sulfur content and hence highest liquidus temperature. Here, using a new model for the internal evolution of the IVB parent body, we show that a single stage of metal-silicate separation cannot account for the complete melting of pure Fe metal at the relatively late time given by the Hf-W model age. Instead, a complex metal-silicate separation scenario is required that includes migration of partial silicate melts, formation of a shallow magma ocean, and core formation in two distinct stages of metal segregation. In the first stage, a protocore formed at ≈1.5 Ma via settling of metal particles in a mantle magma ocean, followed by metal segregation from a shallow magma ocean at ≈5.4 Ma. As these stages of metal segregation occurred at different times, the two metal fractions had different 182W compositions. Consequently, the final 182W composition of the IVB core does not correspond to a single differentiation event, but represents the average composition of early- and late-segregated core fractions. Our best fit model indicates an ≈100 km radius for the IVB parent body and provides an accretion age of ≈0.1-0.5 Ma after solar system formation. The computed solidification time is, furthermore, consistent with the Re-Os age for crystallization of the IVB core.

  17. 24 GHz cmWave Radio Propagation Through Vegetation

    DEFF Research Database (Denmark)

    Rodriguez, Ignacio; Abreu, Renato Barbosa; Portela Lopes de Almeida, Erika

    2016-01-01

    This paper presents a measurement-based analysis of cm-wave radio propagation through vegetation at 24 GHz. A set of dedicated directional measurements were performed with horn antennas located close to street level inside a densely-vegetated area illuminated from above. The full azimuth was exam......This paper presents a measurement-based analysis of cm-wave radio propagation through vegetation at 24 GHz. A set of dedicated directional measurements were performed with horn antennas located close to street level inside a densely-vegetated area illuminated from above. The full azimuth...

  18. Martian Pyroxenes in the Shergottite Meteorites; Zagami, SAU005, DAG476 and EETA79001

    Science.gov (United States)

    Stephen, N.; Benedix, G. K.; Bland, P.; Hamilton, V. E.

    2010-12-01

    The geology and surface mineralogy of Mars is characterised using remote sensing techniques such as thermal emission spectroscopy (TES) from instruments on a number of spacecraft currently orbiting Mars or gathered from roving missions on the Martian surface. However, the study of Martian meteorites is also important in efforts to further understand the geological history of Mars or to interpret mission data as they are believed to be the only available samples that give us direct clues as to Martian igneous processes [1]. We have recently demonstrated that the spectra of Martian-specific minerals can be determined using micro-spectroscopy [2] and that these spectra can be reliably obtained from thin sections of Martian meteorites [3]. Accurate modal mineralogy of these meteorites is also important [4]. In this study we are using a variety of techniques to build upon previous studies of these particular samples in order to fully characterise the nature of the 2 common pyroxenes found in Martian Shergottites; pigeonite and augite [5], [6]. Previous studies have shown that the Shergottite meteorites are dominated by pyroxene (pigeonite and augite in varying quantities) [4], [5], commonly but not always olivine, plagioclase or maskelynite/glass and also hydrous minerals, which separate the Martian meteorites from other achondrites [7]. Our microprobe study of meteorites Zagami, EETA79001, SAU005 and DAG476 in thin-section at the Natural History Museum, London shows a chemical variability within both the pigeonite and augite composition across individual grains in all thin sections; variation within either Mg or Ca concentration varies from core to rim within the grains. This variation can also be seen in modal mineralogy maps using SEM-derived element maps and the Photoshop® technique previously described [4], and in new micro-spectroscopy data, particularly within the Zagami meteorite. New mineral spectra have been gathered from the Shergottite thin-sections by

  19. Evolution of carbonaceous chondrite parent bodies: Insights into cometary nuclei

    International Nuclear Information System (INIS)

    McSween, H.Y. Jr.

    1989-01-01

    It is thought that cometary samples will comprise the most primitive materials that are able to be sampled. Although parent body alteration of such samples would not necessarily detract from scientists' interest in them, the possibility exists that modification processes may have affected cometary nuclei. Inferences about the kinds of modifications that might be encountered can be drawn from data on the evolution of carbonaceous chondrite parent bodies. Observations suggest that, of all the classes of chondrites, these meteorites are most applicable to the study of comets. If the proportion of possible internal heat sources such as Al-26 in cometary materials are similar to those in chondrites, and if the time scale of comet accretion was fast enough to permit incorporation of live radionuclides, comets might have had early thermal histories somewhat like those of carbonaceous chondrite parent bodies

  20. Operation of a Five-Stage 40,000-CM2-Area Insulator Stack at 158 KV/CM

    International Nuclear Information System (INIS)

    Anderson RA; Clark, Robert E; Corcoran, PA; Douglas, John W; Gilliland, TL; Horry, ML; Hughes, Thomas P; Ives, HC; Long, FW; Martin, TH; McDaniel, DH; Milton, Osborne; Mostrom, Michael A; Seamen, JF; Shoup, RW; Smith, ID; Smith, JW; Spielman, RB; Struve, KW; Stygar, WA; Vogtlin, George E; Wagoner, TC; Yamamoto, Osamu

    1999-01-01

    We have demonstrated successful operation of a 3.35- m-diameter insulator stack at 158 kV/cm on five consecutive Z-accelerator shots. The stack consisted of five +45 deg;-profile 5.715-cm-thick cross-linked-polystyrene (Rexolite- 1422) insulator rings, and four anodized- aluminum grading rings shaped to reduce the field at cathode triple junctions. The width of the voltage pulse at 89% of peak was 32 ns. We compare this result to a new empirical flashover relation developed from previous small-insulator experiments conducted with flat unanodized electrodes. The relation predicts a 50% flashover probability for a Rexolite insulator during an applied voltage pulse when E max e -0.27/d (t eff C) 1/10 = 224, where E max is the peak mean electric field (kV/cm), d is the insulator thickness (cm), t eff is the effective pulse width (ps), and C is the insulator circumference (cm). We find the Z stack can be operated at a stress at least 19% higher than predicted. This result, and previous experiments conducted by Vogtlin, suggest anodized electrodes with geometries that reduce the field at both anode and cathode triple junctions would improve the flashover strength of +45 deg; insulators

  1. Microstructures, mineral chemistry, noble gases and nitrogen in the recent fall, Bhuka iron (IAB) meteorite

    Science.gov (United States)

    Murty, S. V. S.; Ranjith, P. M.; Ray, Dwijesh; Ghosh, S.; Chattopadhyay, Basab; Shrivastava, K. L.

    2016-10-01

    We report some chemical, petrological and isotopic studies of the Bhuka iron meteorite that fell in Rajasthan, India in 2005. Numerous silicate and graphite inclusions are visible on the surface of the hand specimen. In the polished and etched surface studied, irregular patches of graphite are found as the most dominant inclusion and commonly associated with pure corundum (95 wt% Al2O3), spinel, feldspar and Si-rich phases. Apart from typical lamellar intergrowth with kamacite (i.e. the Widmänstatten pattern), taenites are also commonly found to occur as a rim of the graphite inclusions. P-rich (up to 10 wt%) taenites are also found locally within the recrystallised kamacite matrix. Based on mineralogy, texture and bulk composition, Bhuka resembles the low-Ni IAB subgroup (ungrouped). Noble gas isotope studies suggest He, Ne and Ar are mostly of cosmogenic origin, while Kr and Xe are a mixture of cosmogenic, radiogenic and trapped components. A pre-atmospheric radius of 10±1 cm and a cosmic ray exposure age of 346±52 Ma are derived based on depth dependant (3He/4He)c and 38Arc respectively, as per the production systematics of cosmogenic noble gas isotopes (Ammon et al., 2009). Cosmogenic 83Kr and 126Xe yield production rates of 12 and 0.335 (in 10-15ccSTP/g Ma) for 83Kr and 126Xe respectively. Presence of trapped Kr and Xe, with (84Kr/132Xe)t=2 and radiogenic 129Xe=120×10-12 ccSTP/g are due to presence of graphite/silicate inclusions in the analysed sample. Over 150% excess 131Xec than expected from spallation suggests contribution from (n,ɤ) reactions from Ba from inclusions and suggests irradiation of pre-atmospheric object in a larger body, indicative of complex irradiation. Trapped N of 24 ppm, with δ15N=-10.7±0.8‰ observed in Bhuka, is heavier than the range observed hither to in IAB irons.

  2. The Miller Range 090340 and 090206 meteorites: Identification of new brachinite-like achondrites with implications for the diversity and petrogenesis of the brachinite clan

    Science.gov (United States)

    Goodrich, Cyrena Anne; Kita, Noriko T.; Sutton, Stephen R.; Wirick, Sue; Gross, Juliane

    2017-05-01

    .07, respectively, similar to those of three brachinites also analyzed here (Brachina, Hughes 026, Nova 003). They are higher than those of olivine in ureilites, even those containing chromite. The valence systematics of MIL 090340, MIL 090206, and the three analyzed brachinites (lower Fo = more oxidized Cr) are consistent with previous evidence that brachinite-like parent bodies were inherently more oxidized than the ureilite parent body. The symplectic orthopyroxene + sulfide/metal assemblages in MIL 090340, MIL 090206, and many brachinite clan meteorites have superficial similarities to characteristic "reduction rims" in ureilites. However, they differ significantly in detail. They likely formed by reaction of olivine with S-rich fluids, with only minor reduction. MIL 090340 and the granoblastic area of MIL 090206 are similar in modal mineralogy and texture to most brachinites, but have higher Fo values typical of brachinite-like achondrites. The poikilitic pyroxene area of MIL 090206 is more typical of brachinite-like achondrites. The majority of their properties suggest that MIL 090340 and MIL 090206 are residues of low-degree partial melting. The poikilitic area of MIL 090206 could be a result of limited melt migration, with trapping and recrystallization of a small volume of melt in the residual matrix. These two samples are so similar in mineral compositions, Cr valence, and cosmic ray exposure ages that they could be derived from the same lithologic unit on a common parent body.

  3. How accurately can 21cm tomography constrain cosmology?

    Science.gov (United States)

    Mao, Yi; Tegmark, Max; McQuinn, Matthew; Zaldarriaga, Matias; Zahn, Oliver

    2008-07-01

    There is growing interest in using 3-dimensional neutral hydrogen mapping with the redshifted 21 cm line as a cosmological probe. However, its utility depends on many assumptions. To aid experimental planning and design, we quantify how the precision with which cosmological parameters can be measured depends on a broad range of assumptions, focusing on the 21 cm signal from 6noise, to uncertainties in the reionization history, and to the level of contamination from astrophysical foregrounds. We derive simple analytic estimates for how various assumptions affect an experiment’s sensitivity, and we find that the modeling of reionization is the most important, followed by the array layout. We present an accurate yet robust method for measuring cosmological parameters that exploits the fact that the ionization power spectra are rather smooth functions that can be accurately fit by 7 phenomenological parameters. We find that for future experiments, marginalizing over these nuisance parameters may provide constraints almost as tight on the cosmology as if 21 cm tomography measured the matter power spectrum directly. A future square kilometer array optimized for 21 cm tomography could improve the sensitivity to spatial curvature and neutrino masses by up to 2 orders of magnitude, to ΔΩk≈0.0002 and Δmν≈0.007eV, and give a 4σ detection of the spectral index running predicted by the simplest inflation models.

  4. Maribo—a new CM fall from Denmark

    DEFF Research Database (Denmark)

    Haack, Henning; Grau, Thomas; Bischoff, Addi

    2012-01-01

    Maribo is a new Danish CM chondrite, which fell on January 17, 2009, at 19:08:28 CET. The fall was observed by many eye witnesses and recorded by a surveillance camera, an all sky camera, a few seismic stations, and by meteor radar observatories in Germany. A single fragment of Maribo with a dry...

  5. 3 cm cryogenic electron linac for defectoscopy and medicine

    International Nuclear Information System (INIS)

    Androsov, V.V.; Saverskij, A.Ya.; Shchedrin, I.S.

    1979-01-01

    Comparative estimations of basic HF parameters of travelling and standing wave accelerating structures of cryogenic variants are given. A possibility for using liquid nitrogen as coolant has been considered. Changes in energy attenuation and storage along 1 m length for circular corrugated wavequide (CCW) when changing copper temperature from room to liquid nitrogen temperature has been considered as well. It is shown that nitrogen cooling does not result in significant energy gain for travelling wave CCW, however considerably decreases a share of power for attenuation in walls: electron efficiency of the accelerator may be increased at the expense of this share of power conserving energy storage a t the same level. Examination of the accelerating structure in the standing wave regime has shown that it is possible to gain considerably with respect to the field in comparison with 70 cm wave length when cooling 3 cm-wave length section with liquid nitrogen. At that, time of filling of the accele--rating cell with accelerating field reduces almost 3 times as compared to a ''hot'' 10 cm version. It is shown that liquid nitrogen consumption will amount not more than 2l/h for cooling of 1 m long 3 cm accelerating structure [ru

  6. Retrofit and acceptance test of 30-cm ion thrusters

    Science.gov (United States)

    Poeschel, R. L.

    1981-01-01

    Six 30 cm mercury thrusters were modified to the J-series design and evaluated using standardized test procedures. The thruster performance meets the design objectives (lifetime objective requires verification), and documentation (drawings, etc.) for the design is completed and upgraded. The retrofit modifications are described and the test data for the modifications are presented and discussed.

  7. Calorimetric determination of kQ factors for NE 2561 and NE 2571 ionization chambers in 5 cm x 5 cm and 10 cm x 10 cm radiotherapy beams of 8 MV and 16 MV photons.

    Science.gov (United States)

    Krauss, Achim; Kapsch, Ralf-Peter

    2007-10-21

    The relative uncertainty of the ionometric determination of the absorbed dose to water, D(w), in the reference dosimetry of high-energy photon beams is in the order of 1.5% and is dominated by the uncertainty of the calculated chamber- and energy-dependent correction factors k(Q). In the present investigation, k(Q) values were determined experimentally in 5 cm x 5 cm and 10 cm x 10 cm radiotherapy beams of 8 MV and 16 MV bremsstrahlung by means of a water calorimeter operated at 4 degrees C. Ionization chambers of the types NE 2561 and NE 2571 were calibrated directly in the water phantom of the calorimeter. The measurements were carried out at the linear accelerator of the Physikalisch-Technische Bundesanstalt. It is shown that the k(Q) factor of a single ionization chamber can be measured with a standard uncertainty of less than 0.3%. No significant variations of k(Q) were found for the different lateral sizes of the radiation fields used in this investigation.

  8. Observations of Isotope Fractionation in Prestellar Cores: Interstellar Origin of Meteoritic Hot Spot?

    Science.gov (United States)

    Milam, S. N.; Charnley, S. B.

    2011-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is thought, in some cases, to trace interstellar material that was incorporated into the solar system without undergoing significant processing. Here, we show the results of models and observations of the nitrogen and carbon fractionation in proto-stellar cores.

  9. Physical properties, structure and fracturing of the Chelyabinsk LL5 meteorite body

    Czech Academy of Sciences Publication Activity Database

    Grokhovsky, V. I.; Kohout, Tomáš; Gritsevich, M.; Koneva, E. V.

    2014-01-01

    Roč. 49, Special issue 1 (2014), pdf 5364-pdf 5364 ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /77./. 08.09.2014-13.09.2014, Casablanca] Institutional support: RVO:67985831 Keywords : Chelyabinsk * LL chondrite * physical properties * structure * mechanical properties * stress Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics http://www.hou.usra.edu/meetings/metsoc2014/pdf/5364.pdf

  10. What Do We Know About the "Carancas-Desaguadero" Fireball, Meteorite and Impact Crater?

    Science.gov (United States)

    Tancredi, G.; Ishitsuka, J.; Rosales, D.; Vidal, E.; Dalmau, A.; Pavel, D.; Benavente, S.; Miranda, P.; Pereira, G.; Vallejos, V.; Varela, M. E.; Brandstätter, F.; Schultz, P. H.; Harris, R. S.; Sánchez, L.

    2008-03-01

    On September 15, 2007, at noon local time, a fireball was observed and heard in the southern shore of the Lake Titicaca, close to the border between Peru and Bolivia. A crater was formed due to the impact of a chondrite meteorite weighing more than 2 tons.

  11. The New Peruvian Meteorite Carancas: Mössbauer Spectroscopy and X-Ray Diffraction Studies

    Science.gov (United States)

    Munayco, P.; Munayco, J.; Varela, M. E.; Scorzelli, R. B.

    2013-02-01

    The Carancas meteorite fell on 15 September 2007 approximately 10 km south of Desaguadero, near Lake Titicaca, Peru, producing bright lights, clouds of dust in the sky and intense detonations. The Carancas meteorite is classified as a H4-5 ordinary chondrite with shock stage S3 and a degree of weathering W0. The Carancas meteorite is characterized by well defined chondrules composed either of olivine or pyroxene. The Mössbauer spectra show an overlapping of paramagnetic and magnetic phases. The spectra show two quadrupole doublets associated to olivine and pyroxene; and two magnetic sextets, associated with the primary phases kamacite/taenite and Troilite (Fe2+). Metal particles were extracted from the bulk powdered samples exhibit only kamacite and small amounts of the intergrowth tetrataenite/antitaenite. X-Ray diffractogram shows the primary phases olivine, pyroxene, troilite, kamacite, diopside and albite. Iron oxides has not been detected by Mössbauer spectroscopy or XRD as can be expected for a meteorite immediately recovered after its fall.

  12. U-Pb systematics in iron meteorites: uniformity of primordial lead

    International Nuclear Information System (INIS)

    Goepel, C.; Manhes, G.; Allegre, C.J.

    1985-01-01

    Pb isotopic compositions and U-Pb abundances were determined in the metal phase of six iron meteorites: Canyon Diablo IA, Toluca IA, Odessa IA, Youndegin IA, Deport IA and Mundrabilla An. Prior to complete dissolution, samples were subjected to a series of leachings and partial dissolutions. Isotopic compositions and abundances of the etched Pb indicate a contamination by terrestrial Pb which is attributable to previous cutting of the meteorite. Pb isotopic compositions measured in the decontaminated samples are identical within 0.2% and essentially confirm the primordial Pb value defined by Tatsumoto et al. (1973). These data invalidate more radiogenic Pb isotopic compositions published for iron meteorites, which are the result of terrestrial Pb contamination introduced mainly by analytical procedure. Our results support the idea of a solar nebula which was isotopically homogeneous for Pb 4.55 Ga ago. The new upper limit for U-abundance in iron meteorites, 0.001 ppb, is in agreement with its expected thermodynamic solubility in the metal phase. (author)

  13. Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites

    Science.gov (United States)

    Cooper, George; Rios, Andro C.

    2016-06-01

    Biological polymers such as nucleic acids and proteins are constructed of only one—the d or l—of the two possible nonsuperimposable mirror images (enantiomers) of selected organic compounds. However, before the advent of life, it is generally assumed that chemical reactions produced 50:50 (racemic) mixtures of enantiomers, as evidenced by common abiotic laboratory syntheses. Carbonaceous meteorites contain clues to prebiotic chemistry because they preserve a record of some of the Solar System’s earliest (˜4.5 Gy) chemical and physical processes. In multiple carbonaceous meteorites, we show that both rare and common sugar monoacids (aldonic acids) contain significant excesses of the d enantiomer, whereas other (comparable) sugar acids and sugar alcohols are racemic. Although the proposed origins of such excesses are still tentative, the findings imply that meteoritic compounds and/or the processes that operated on meteoritic precursors may have played an ancient role in the enantiomer composition of life’s carbohydrate-related biopolymers.

  14. AMMONIA IN THE EARLY SOLAR SYSTEM: AN ACCOUNT FROM CARBONACEOUS METEORITES

    International Nuclear Information System (INIS)

    Pizzarello, S.; Williams, L. B.

    2012-01-01

    This study presents a survey of abundance distribution and isotopic composition of the ammonia found incorporated in the kerogen-like insoluble material of selected carbonaceous chondrite meteorites; the ammonia was released upon hydrothermal treatment at 300°C and 100 MPa. With the exception of Allende, a metamorphosed and highly altered stone, all the insoluble organic materials (IOM) of the meteorites analyzed released significant amounts of ammonia, which varied from over 4 μg mg –1 for the Orgueil IOM to 0.5 μg mg –1 for that of Tagish Lake; the IOM of the pristine Antarctica find GRA95229 remains the most rich in freeable ammonia with 10 μg mg –1 . While the amounts of IOM bound ammonia do not appear to vary between meteorites with a recognizable trend, a possible consequence of long terrestrial exposure of some of the stones, we found that the δ 15 N composition of the ammonia-carrying materials is clearly distinctive of meteorite types and may reflect a preservation of the original 15 N distribution of pre- and proto-solar materials.

  15. Ammonia in the Early Solar System: An Account from Carbonaceous Meteorites

    Science.gov (United States)

    Pizzarello, S.; Williams, L. B.

    2012-04-01

    This study presents a survey of abundance distribution and isotopic composition of the ammonia found incorporated in the kerogen-like insoluble material of selected carbonaceous chondrite meteorites; the ammonia was released upon hydrothermal treatment at 300°C and 100 MPa. With the exception of Allende, a metamorphosed and highly altered stone, all the insoluble organic materials (IOM) of the meteorites analyzed released significant amounts of ammonia, which varied from over 4 μg mg-1 for the Orgueil IOM to 0.5 μg mg-1 for that of Tagish Lake; the IOM of the pristine Antarctica find GRA95229 remains the most rich in freeable ammonia with 10 μg mg-1. While the amounts of IOM bound ammonia do not appear to vary between meteorites with a recognizable trend, a possible consequence of long terrestrial exposure of some of the stones, we found that the δ15N composition of the ammonia-carrying materials is clearly distinctive of meteorite types and may reflect a preservation of the original 15N distribution of pre- and proto-solar materials.

  16. AMMONIA IN THE EARLY SOLAR SYSTEM: AN ACCOUNT FROM CARBONACEOUS METEORITES

    Energy Technology Data Exchange (ETDEWEB)

    Pizzarello, S. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604 (United States); Williams, L. B., E-mail: pizzar@asu.edu [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States)

    2012-04-20

    This study presents a survey of abundance distribution and isotopic composition of the ammonia found incorporated in the kerogen-like insoluble material of selected carbonaceous chondrite meteorites; the ammonia was released upon hydrothermal treatment at 300 Degree-Sign C and 100 MPa. With the exception of Allende, a metamorphosed and highly altered stone, all the insoluble organic materials (IOM) of the meteorites analyzed released significant amounts of ammonia, which varied from over 4 {mu}g mg{sup -1} for the Orgueil IOM to 0.5 {mu}g mg{sup -1} for that of Tagish Lake; the IOM of the pristine Antarctica find GRA95229 remains the most rich in freeable ammonia with 10 {mu}g mg{sup -1}. While the amounts of IOM bound ammonia do not appear to vary between meteorites with a recognizable trend, a possible consequence of long terrestrial exposure of some of the stones, we found that the {delta}{sup 15}N composition of the ammonia-carrying materials is clearly distinctive of meteorite types and may reflect a preservation of the original {sup 15}N distribution of pre- and proto-solar materials.

  17. The instrumentally recorded fall of the Križevci meteorite, Croatia, February 4, 2011

    Czech Academy of Sciences Publication Activity Database

    Borovička, Jiří; Spurný, Pavel; Šegon, D.; Andreić, Z.; Kac, J.; Korlević, K.; Atanackov, J.; Kladnik, G.; Mucke, H.; Vida, D.; Novoselnik, F.

    2015-01-01

    Roč. 50, č. 7 (2015), s. 1244-1259 ISSN 1086-9379 R&D Projects: GA ČR(CZ) GAP209/11/1382 Institutional support: RVO:67985815 Keywords : innisfree meteorite * fragmentation * meteoroids Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.819, year: 2015

  18. Supply of the numerical simulation for the evaluation of the sonic boom of meteorites

    International Nuclear Information System (INIS)

    Henneton, Martin

    2013-01-01

    Within the framework of the Comprehensive Nuclear-Test-Ban Treaty, infra-sound is one survey technique monitoring nuclear explosions. These ones have to be distinguished from natural sources of infra-sound like atmospheric meteorite entries. With a view to investigate meteorites as an infra-sound source, finite volume simulations of the hypersonic flow are performed at sufficiently far distances to reach the acoustic regime. They are then matched to a nonlinear ray tracing method to propagate the signal within the atmosphere down to the ground. For perfect gases, this approach allows us to validate the theoretical model based on simplifying assumptions. More realistic simulations in real gases at thermochemical equilibrium, show a major modification of the pressure field in the near field but a moderate influence for infra-sound at the ground level. Numerical results are compared to infra-sound and seismic measurements in the case of the well-documented meteorite of Carancas (Peru, 2007). This confrontation highlights a good agreement for the spectrum of the waveform but a large overestimation of the overpressure at receptors located near the impact crater. This study also allowed us to propose a new entry trajectory for the meteorite, and to identify one of the recorded signals as a sonic boom. (author) [fr

  19. Magnetic paleofield estimates for chondrules extracted from Bjurbole (L4) meteorite

    Czech Academy of Sciences Publication Activity Database

    Kletetschka, Günther; Wasilewski, P.; Zila, V.

    2005-01-01

    Roč. 40, Supplement 9 (2005), s. 82-82 ISSN 0026-1114. [Annual Meeting of the Meteoritical Society /68./. 12.09.2005-16.09.2005, Gatlinburg] Institutional research plan: CEZ:AV0Z30130516 Keywords : paleomagnetism * solar nebula * chondrules Subject RIV: BM - Solid Matter Physics ; Magnetism

  20. Gamma-emissions of some meteorites and terrestrial rocks. Evaluation of lunar soil radioactivity

    International Nuclear Information System (INIS)

    Nordemann, D.

    1966-01-01

    The gamma-emissions of some terrestrial rocks and of the following meteorites: Bogou, Eagle-Station, Granes, and Dosso were studied by quantitative low background gamma spectrometry. These measurements and their interpretation lead to the evaluation of the possible gamma-emissions of several models of lunar soils. (author) [fr