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Sample records for allan hills meteorites

  1. Carbon-14 ages of Allan Hills meteorites and ice

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.; Norris, T.

    1982-01-01

    Allan Hills is a blue ice region of approximately 100 sq km area in Antarctica where many meteorites have been found exposed on the ice. The terrestrial ages of the Allan Hills meteorites, which are obtained from their cosmogenic nuclide abundances are important time markers which can reflect the history of ice movement to the site. The principal purpose in studying the terrestrial ages of ALHA meteorites is to locate samples of ancient ice and analyze their trapped gas contents. Attention is given to the C-14 and Ar-39 terrestrial ages of ALHA meteorites, and C-14 ages and trapped gas compositions in ice samples. On the basis of the obtained C-14 terrestrial ages, and Cl-36 and Al-26 results reported by others, it is concluded that most ALHA meteorites fell between 20,000 and 200,000 years ago.

  2. Exposure and terrestrial ages of four Allan Hills Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Kirsten, T.; Ries, D.; Fireman, E. L.

    1978-01-01

    Terrestrial ages of meteorites are based on the amount of cosmic-ray-produced radioactivity in the sample and the number of observed falls that have similar cosmic-ray exposure histories. The cosmic-ray exposures are obtained from the stable noble gas isotopes. Noble gas isotopes are measured by high-sensitivity mass spectrometry. In the present study, the noble gas contents were measured in four Allan Hill meteorites (No. 5, No. 6, No. 7, and No. 8), whose C-14, Al-26, and Mn-53 radioactivities are known. These meteorites are of particular interest because they belong to a large assemblage of distinct meteorites that lie exposed on a small (110 sq km) area of ice near the Allan Hills.

  3. Cosmic-ray-produced Cl-36 and Mn-53 in Allan Hills-77 meteorites

    NASA Technical Reports Server (NTRS)

    Nishiizumi, K.; Murrell, M. T.; Arnold, J. R.; Finkel, R. C.; Elmore, D.; Ferraro, R. D.; Gove, H. E.

    1981-01-01

    Cosmic-ray-produced Mn-53 has been determined by neutron activation in nine Allan Hills-77 meteorites. Additionally, Cl-36 has been measured in seven of these objects using tandem accelerator mass spectrometry. These results, along with C-14 and Al-26 concentrations determined elsewhere, yield terrestrial ages ranging from 10,000 to 700,000 years. Weathering was not found to result in Mn-53 loss.

  4. The natural thermoluminescence of meteorites. V - Ordinary chondrites at the Allan Hills ice fields

    NASA Technical Reports Server (NTRS)

    Benoit, Paul H.; Sears, Hazel; Sears, Derek W. G.

    1993-01-01

    Natural thermoluminescence (TL) data have been obtained for 167 ordinary chondrites from the ice fields in the vicinity of the Allan Hills in Victoria Land, Antarctica, in order to investigate their thermal and radiation history, pairing, terrestrial age, and concentration mechanisms. Natural TL values for meteorites from the Main ice field are fairly low, while the Farwestern field shows a spread with many values 30-80 krad, suggestive of less than 150-ka terrestrial ages. There appear to be trends in TL levels within individual ice fields which are suggestive of directions of ice movement at these sites during the period of meteorite concentration. These directions seem to be confirmed by the orientations of elongation preserved in meteorite pairing groups. The proportion of meteorites with very low natural TL levels at each field is comparable to that observed at the Lewis Cliff site and for modern non-Antarctic falls and is also similar to the fraction of small perihelia orbits calculated from fireball and fall observations. Induced TL data for meteorites from the Allan Hills confirm trends which show that a select group of H chondrites from the Antarctic experienced a different extraterrestrial thermal history to that of non-Antarctic H chondrites.

  5. Investigations into an unknown organism on the martian meteorite Allan Hills 84001

    NASA Technical Reports Server (NTRS)

    Steele, A.; Goddard, D. T.; Stapleton, D.; Toporski, J. K.; Peters, V.; Bassinger, V.; Sharples, G.; Wynn-Williams, D. D.; McKay, D. S.

    2000-01-01

    Examination of fracture surfaces near the fusion crust of the martian meteorite Allan Hills (ALH) 84001 have been conducted using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and has revealed structures strongly resembling mycelium. These structures were compared with similar structures found in Antarctic cryptoendolithic communities. On morphology alone, we conclude that these features are not only terrestrial in origin but probably belong to a member of the Actinomycetales, which we consider was introduced during the Antarctic residency of this meteorite. If true, this is the first documented account of terrestrial microbial activity within a meteorite from the Antarctic blue ice fields. These structures, however, do not bear any resemblance to those postulated to be martian biota, although they are a probable source of the organic contaminants previously reported in this meteorite.

  6. The Natural Thermoluminescence of Meteorites. Part 5; Ordinary Chondrites at the Allan Hills Ice Fields

    NASA Technical Reports Server (NTRS)

    Benoit, Paul H.; Sears, Hazel; Sears, Derek W. G.

    1993-01-01

    Natural thermoluminescence (TL) data have been obtained for 167 ordinary chondrites from the ice fields in the vicinity of the Allan Hills in Victoria Land, Antarctica, in order to investigate their thermal and radiation history, pairing, terrestrial age, and concentration mechanisms. Using fairly conservative criteria (including natural and induced TL, find location, and petrographic data), the 167 meteorite fragments are thought to represent a maximum of 129 separate meteorites. Natural TL values for meteorites from the Main ice field are fairly low (typically 5-30 krad, indicative of terrestrial ages of approx. 400 ka), while the Far western field shows a spread with many values 30-80 krad, suggestive of less then 150-ka terrestrial ages. There appear to be trends in TL levels within individual ice fields which are suggestive of directions of ice movement at these sites during the period of meteorite concentration. These directions seem to be confirmed by the orientations of elongation preserved in meteorite pairing groups. The proportion of meteorites with very low natural TL levels (less then 5 krad) at each field is comparable to that observed at the Lewis Cliff site and for modern non-Antarctic falls and is also similar to the fraction of small perihelia (less then 0.85 AU) orbits calculated from fireball and fall observations. Induced TL data for meteorites from the Allan Hills confirm trends observed for meteorites collected during the 1977/1978 and 1978/1979 field seasons which show that a select group of H chondrites from the Antarctic experienced a different extraterrestrial thermal history to that of non-Antarctic H chondrites.

  7. Element distribution and noble gas isotopic abundances in lunar meteorite Allan Hills A81005

    NASA Technical Reports Server (NTRS)

    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.

  8. Mineral Biomarkers in Martian Meteorite Allan Hills 84001?

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, K. L.; Bazylinski, D. A.; Wentworth, S. J.; McKay, D. S.; Golden, D. C.; Gibson, E. K., Jr.; Romanek, C. S.

    1998-01-01

    The occurrence of fine-grained magnetite in the Fe-rich rims surrounding carbonate globules in the martian meteorite ALH84001, originally described in , have been proposed as fossil remains of primitive martian organisms. Here we report observations on size and shape distributions of magnetites from ALH84001 and compare them to biogenic and inorganic magnetite crystals of terrestrial origin. While some magnetite morphology is not unequivocally diagnostic for its biogenicity, such as cubodial forms of magnetite, which are common in inorganically formed magnetites, other morphologies of magnetite (parallel-epiped or elongated prismatic and arrowhead forms) are more likely signatures of biogenic activity. Some ALH 84001 magnetite particles described below have unique morphology and length-to-width ratios that are indistinguishable from a variety of terrestrial biogenic magnetite and distinct from all known inorganic forms of magnetite.

  9. Allan Hills 76005 Polymict Eucrite Pairing Group: Curatorial and Scientific Update on a Jointly Curated Meteorite

    NASA Technical Reports Server (NTRS)

    Righter, K.

    2011-01-01

    Allan Hills 76005 (or 765) was collected by the joint US-Japan field search for meteorites in 1976-77. It was described in detail as "pale gray in color and consists of finely divided macrocrystalline pyroxene-rich matrix that contains abundant clastic fragments: (1) Clasts of white, plagioclase-rich rocks. (2) Medium-gray, partly devitrified, cryptocrystalline. (3) Monomineralic fragments and grains of pyroxene, plagioclases, oxide minerals, sulfides, and metal. In overall appearance it is very similar to some lunar breccias." Subsequent studies found a great diversity of basaltic clast textures and compositions, and therefore it is best classified as a polymict eucrite. Samples from the 1976-77, 77-78, and 78-79 field seasons (76, 77, and 78 prefixes) were split between US and Japan (NIPR). The US specimens are currently at NASA-JSC, Smithsonian Institution, or the Field Museum in Chicago. After this initial finding of ALH 76005, the next year s team recovered one additional mass ALH 77302, and then four additional masses were found during the third season ALH 78040 and ALH 78132, 78158 and 78165. The joint US-Japan collection effort ended after three years and the US began collecting in the Trans-Antarctic Mountains with the 1979-80 and subsequent field seasons. ALH 79017 and ALH 80102 were recovered in these first two years, and then in 1981-82 field season, 6 additional masses were recovered from the Allan Hills. Of course it took some time to establish pairing of all of these specimens, but altogether the samples comprise 4292.4 g of material. Here will be summarized the scientific findings as well as some curatorial details of how specimens have been subdivided and allocated for study. A detailed summary is also presented on the NASA-JSC curation webpage for the HED meteorite compendium.

  10. Carbonates in fractures of Martian meteorite Allan Hills 84001: petrologic evidence for impact origin

    NASA Technical Reports Server (NTRS)

    Scott, E. R.; Krot, A. N.; Yamaguchi, A.

    1998-01-01

    Carbonates in Martian meteorite Allan Hills 84001 occur as grains on pyroxene grain boundaries, in crushed zones, and as disks, veins, and irregularly shaped grains in healed pyroxene fractures. Some carbonate disks have tapered Mg-rich edges and are accompanied by smaller, thinner and relatively homogeneous, magnesite microdisks. Except for the microdisks, all types of carbonate grains show the same unique chemical zoning pattern on MgCO3-FeCO3-CaCO3 plots. This chemical characteristic and the close spatial association of diverse carbonate types show that all carbonates formed by a similar process. The heterogeneous distribution of carbonates in fractures, tapered shapes of some disks, and the localized occurrence of Mg-rich microdisks appear to be incompatible with growth from an externally derived CO2-rich fluid that changed in composition over time. These features suggest instead that the fractures were closed as carbonates grew from an internally derived fluid and that the microdisks formed from a residual Mg-rich fluid that was squeezed along fractures. Carbonate in pyroxene fractures is most abundant near grains of plagioclase glass that are located on pyroxene grain boundaries and commonly contain major or minor amounts of carbonate. We infer that carbonates in fractures formed from grain boundary carbonates associated with plagiociase that were melted by impact and dispersed into the surrounding fractured pyroxene. Carbonates in fractures, which include those studied by McKay et al. (1996), could not have formed at low temperatures and preserved mineralogical evidence for Martian organisms.

  11. Bulk and stable isotopic compositions of carbonate minerals in Martian meteorite Allan Hills 84001: no proof of high formation temperature.

    PubMed

    Treiman, A H; Romanek, C S

    1998-07-01

    Understanding the origin of carbonate minerals in the Martian meteorite Allan Hills (ALH) 84001 is crucial to evaluating the hypothesis that they contain traces of ancient Martian life. Using arguments based on chemical equilibria among carbonates and fluids, an origin at >650 degrees C (inimical to life) has been proposed. However, the bulk and stable isotopic compositions of the carbonate minerals are open to multiple interpretations and so lend no particular support to a high-temperature origin. Other methods (possibly less direct) will have to be used to determine the formation temperature of the carbonates in ALH84001. PMID:11543073

  12. Bulk and Stable Isotopic Compositions of Carbonate Minerals in Martian Meteorite Allan Hills 84001: No Proof of High Formation Temperature

    NASA Technical Reports Server (NTRS)

    Treiman, Allan H.; Romanek, Christopher S.

    1998-01-01

    Understanding the origin of carbonate minerals in the Martian meteorite Allan Hills (ALH) 84001 is crucial to evaluating the hypothesis that they contain traces of ancient Martian life. Using arguments based on chemical equilibria among carbonates and fluids, an origin at greater than 650 C (inimical to life) has been proposed. However, the bulk and stable isotopic compositions of the carbonate minerals are open to multiple interpretations and so lend no particular support to a high-temperature origin. Other methods (possibly less direct) will have to be used to determine the formation temperature of the carbonates in ALH 84001.

  13. Thermoluminescence survey of 12 meteorites collected by the European 1988 Antarctic meteorite expedition to Allan Hills and the importance of acid washing for thermoluminescence sensitivity measurements

    NASA Technical Reports Server (NTRS)

    Benoit, P. H.; Sears, H.; Sears, D. W. G.

    1991-01-01

    Natural and induced thermoluminescence (TL) data are reported for 12 meteorites recovered from the Allan Hills region of Antarctica by the European field party during the 1988/1989 field season. The samples include one with extremely high natural TL, ALH88035, suggestive of exposure to unusually high radiation doses (i.e., low degrees of shielding), and one, ALH88034, whose low natural TL suggests reheating within the last 100,000 years. The remainder have natural TL values suggestive of terrestrial ages similar to those of other meteorites from Allan Hills. ALH88015 (L6) has induced TL data suggestive of intense shock. TL sensitivities of these meteorites are generally lower than observed falls of their petrologic types, as is also observed for Antarctic meteorites in general. Acid-washing experiments indicate that this is solely the result of terrestrial weathering rather than a nonterrestrial Antarctic-non-Antarctic difference. However, other TL parameters, such as natural TL and induced peak temperature-width, are unchanged by acid washing and are sensitive indicators of a meteorite's metamorphic and recent radiation history.

  14. Thermoluminescence survey of 12 meteorites collected by the European 1988 Antarctic meteorite expedition to Allan Hills and the importance of acid washing for thermoluminescence sensitivity measurements

    SciTech Connect

    Benoit, P.H.; Sears, H.; Sears, D.W.G. )

    1991-06-01

    Natural and induced thermoluminescence (TL) data are reported for 12 meteorites recovered from the Allan Hills region of Antarctica by the European field party during the 1988/1989 field season. The samples include one with extremely high natural TL, ALH88035, suggestive of exposure to unusually high radiation doses (i.e., low degrees of shielding), and one, ALH88034, whose low natural TL suggests reheating within the last 100,000 years. The remainder have natural TL values suggestive of terrestrial ages similar to those of other meteorites from Allan Hills. ALH88015 (L6) has induced TL data suggestive of intense shock. TL sensitivities of these meteorites are generally lower than observed falls of their petrologic types, as is also observed for Antarctic meteorites in general. Acid-washing experiments indicate that this is solely the result of terrestrial weathering rather than a nonterrestrial Antarctic-non-Antarctic difference. However, other TL parameters, such as natural TL and induced peak temperature-width, are unchanged by acid washing and are sensitive indicators of a meteorite's metamorphic and recent radiation history. 16 refs.

  15. Isotopic evidence for a terrestrial source of organic compounds found in martian meteorites Allan Hills 84001 and Elephant Moraine 79001.

    PubMed

    Jull, A J; Courtney, C; Jeffrey, D A; Beck, J W

    1998-01-16

    Stepped-heating experiments on martian meteorites Allan Hills 84001 (ALH84001) and Elephant Moraine 79001 (EETA79001) revealed low-temperature (200 to 430 degrees Celsius) fractions with a carbon isotopic composition delta13C between -22 and -33 per mil and a carbon-14 content that is 40 to 60 percent of that of modern terrestrial carbon, consistent with a terrestrial origin for most of the organic material. Intermediate-temperature (400 to 600 degrees Celsius) carbonate-rich fractions of ALH84001 have delta13C of +32 to +40 per mil with a low carbon-14 content, consistent with an extraterrestrial origin, whereas some of the carbonate fraction of EETA79001 is terrestrial. In addition, ALH84001 contains a small preterrestrial carbon component of unknown origin that combusts at intermediate temperatures. This component is likely a residual acid-insoluble carbonate or a more refractory organic phase. PMID:9430584

  16. Magnesian anorthositic granulites in lunar meteorites Allan Hills A81005 and Dhofar 309: Geochemistry and global significance

    NASA Astrophysics Data System (ADS)

    Treiman, Allan H.; Maloy, Amy K.; Shearer, Charles K.; Gross, Juliane

    2010-02-01

    Fragments of magnesian anorthositic granulite are found in the lunar highlands meteorites Allan Hills (ALH) A81005 and Dhofar (Dho) 309. Five analyzed clasts of meteoritic magnesian anorthositic granulite have Mg' [molar Mg/(Mg+Fe)]=81-87 FeO~5%wt Al2O3~22% wt; rare earth elements abundances~0.5-2×CI (except Eu~10×CI) and low Ni and Co in a non-chondritic ratio. The clasts have nearly identical chemical compositions, even though their host meteorites formed at different places on the Moon. These magnesian anorthositic granulites are distinct from other highlands materials in their unique combination of mineral proportions, Mg', REE abundances and patterns, Ti/Sm ratio, and Sc/Sm ratio. Their Mg' is too high for a close relationship to ferroan anorthosites, or to have formed as flotation cumulates from the lunar magma ocean. Compositions of these magnesian anorthositic granulites cannot be modeled as mixtures of, or fractionates from, known lunar rocks. However, compositions of lunar highlands meteorites can be represented as mixtures of magnesian anorthositic granulite, ferroan anorthosite, mare basalt, and KREEP. Meteoritic magnesian anorthositic granulite is a good candidate for the magnesian highlands component inferred from Apollo highland impactites: magnesian, feldspathic, and REE-poor. Bulk compositions of meteorite magnesian anorthositic granulites are comparable to those inferred for parts of the lunar farside (the Feldspathic Highlands Terrane): ~4.5 wt% FeO; ~28 wt% Al2O3; and Th<1ppm. Thus, magnesian anorthositic granulite may be a widespread and abundant component of the lunar highlands.

  17. Fine-Grained Rims in the Allan Hills 81002 and Lewis Cliff 90500 CM2 Meteorites: Their Origin and Modification

    NASA Technical Reports Server (NTRS)

    Hua, X.; Wang, J.; Buseck, P. R.

    2002-01-01

    Antarctic CM meteorites Allan Hills (ALH) 8 1002 and Lewis Cliff (LEW) 90500 contain abundant fine-grained rims (FGRs) that surround a variety of coarse-grained objects. FGRs from both meteorites have similar compositions and petrographic features, independent of their enclosed objects. The FGRs are chemically homogeneous at the 10 m scale for major and minor elements and at the 25 m scale for trace elements. They display accretionary features and contain large amounts of volatiles, presumably water. They are depleted in Ca, Mn, and S but enriched in P. All FGRs show a slightly fractionated rare earth element (REE) pattern, with enrichments of Gd and Yb and depletion of Er. Gd is twice as abundant as Er. Our results indicate that those FGRs are not genetically related to their enclosed cores. They were sampled from a reservoir of homogeneously mixed dust, prior to accretion to their parent body. The rim materials subsequently experienced aqueous alteration under identical conditions. Based on their mineral, textural, and especially chemical similarities, we conclude that ALH 8 1002 and LEW 90500 likely have a similar or identical source.

  18. Cation diffusion in calcite: determining closure temperatures and the thermal history for the Allan Hills 84001 meteorite.

    PubMed

    Fisler, D K; Cygan, R T

    1998-07-01

    The presence of zoned Fe, Mg, Ca, and Mn in the carbonate phases associated with the cracks and inclusions of the Allan Hills (ALH) 84001 meteorite provides evidence for constraining the thermal history of the meteorite. Using self- and tracer-diffusion coefficients obtained from laboratory experiments on natural calcite, cooling rates are calculated for various temperatures and diffusion distances to assist in the evaluation of the compositional zoning associated with the carbonate phases in ALH 84001. The closure temperature model provides the average temperature below which compositional zoning will be preserved for a given cooling rate, that is, the temperature at which diffusion will be ineffective in homogenizing the phase. The validity of various theories for the formation of the carbonate globules may be examined, therefore, in view of the diffusion-limited kinetic constraints. Experiments using a thin film-mineral diffusion couple and ion microprobe for depth profiling analysis were performed for the temperature range of 550-800 degrees C to determine self- and tracer-diffusion coefficients for Ca and Mg and in calcite. The resulting activation energies for Ca (Ea(Ca) = 271 +/- 80 kJ/mol) and for Mg (Ea(Mg) = 284 +/- 74 kJ/mol) were used then to calculate a series of cooling rate, grain size, and closure temperature curves. The data indicate, for example, that by the diffusion of Mg in calcite, a 10 micrometers compositional zone would be completely homogenized at a temperature of 300 degrees C for cooling rates <100 K/Ma. These data provide no constraint on formation models that propose a low-temperature fluid precipitation mechanism; however, they indicate that the carbonate globules were not exposed to a high-temperature environment for long time scales following formation. PMID:11543076

  19. Cation diffusion in calcite: determining closure temperatures and the thermal history for the Allan Hills 84001 meteorite.

    PubMed

    Fisler, D K; Cygan, R T

    1998-07-01

    The presence of zoned Fe, Mg, Ca, and Mn in the carbonate phases associated with the cracks and inclusions of the Allan Hills (ALH) 84001 meteorite provides evidence for constraining the thermal history of the meteorite. Using self- and tracer-diffusion coefficients obtained from laboratory experiments on natural calcite, cooling rates are calculated for various temperatures and diffusion distances to assist in the evaluation of the compositional zoning associated with the carbonate phases in ALH 84001. The closure temperature model provides the average temperature below which compositional zoning will be preserved for a given cooling rate, that is, the temperature at which diffusion will be ineffective in homogenizing the phase. The validity of various theories for the formation of the carbonate globules may be examined, therefore, in view of the diffusion-limited kinetic constraints. Experiments using a thin film-mineral diffusion couple and ion microprobe for depth profiling analysis were performed for the temperature range of 550-800 degrees C to determine self- and tracer-diffusion coefficients for Ca and Mg and in calcite. The resulting activation energies for Ca (Ea(Ca) = 271 +/- 80 kJ/mol) and for Mg (Ea(Mg) = 284 +/- 74 kJ/mol) were used then to calculate a series of cooling rate, grain size, and closure temperature curves. The data indicate, for example, that by the diffusion of Mg in calcite, a 10 micrometers compositional zone would be completely homogenized at a temperature of 300 degrees C for cooling rates <100 K/Ma. These data provide no constraint on formation models that propose a low-temperature fluid precipitation mechanism; however, they indicate that the carbonate globules were not exposed to a high-temperature environment for long time scales following formation.

  20. Age of Allan Hills 82102, a meteorite found inside the ice

    NASA Technical Reports Server (NTRS)

    Nishiizumi, K.; Jull, A. J. T.; Bonani, G.; Suter, M.; Woelfli, W.

    1989-01-01

    The terrestrial age of a meteorite that was recovered from below the surface of Antarctic ice is reported, and it is argued that this represents a measurement of the age of the ice itself. The cosmogenic radionuclides Be-10, C-14, Al-26, Cl-36, and Mn-53 are measured in the meteorite and Be-10 and Cl-36 in the ice. A terrestrial age of 11,000 yr is obtained for the meteorite, which suggests that the snow accumulation area where it fell was only a few tens of km away.

  1. Cosmogenic Radionuclide Contents of Antarctic Meteorites from Allan Hills Having High Natural Thermoluminescence

    NASA Astrophysics Data System (ADS)

    Mokos, J.; Vogt, S.; Lipschutz, M. E.

    1996-03-01

    Cosmic ray bombardment produces stable and radioactive nuclides, as well as thermoluminescence (TL). Concentrations of long-lived radionuclides have been measured in fifteen Antarctic H-chondrites with high TL levels. Sears et al. studied these fifteen meteorites and postulated an unusual history. They noted that two have a young terrestrial age. We decided to examine their irradiation histories by measuring long-lived cosmogenic radionuclides in the fifteen H4-6 chondrites by accelerator mass spectrometry (AMS). The radionuclide concentration, TL data, and petrographic type, supports the idea that these meteorites originated from a single source with a unique orbital history.

  2. Olivine in Martian Meteorite Allan Hills 84001: Evidence for a High-Temperature Origin and Implications for Signs of Life

    NASA Technical Reports Server (NTRS)

    Shearer, C. K.; Leshin, L. A.; Adcock, C. T.

    1999-01-01

    Olivine from Martian meteorite Allan Hills (ALH) 84001 occurs as clusters within orthopyroxene adjacent to fractures containing disrupted carbonate globules and feldspathic shock glass. The inclusions are irregular in shape and range in size from approx. 40 microns to submicrometer. Some of the inclusions are elongate and boudinage-like. The olivine grains are in sharp contact with the enclosing orthopyroxene and often contain small inclusions of chromite The olivine exhibits a very limited range of composition from Fo(sub 65) to Fo(sub 66) (n = 25). The delta(sup 18)O values of the olivine and orthopyroxene analyzed by ion microprobe range from +4.3 to +5.3% and are indistinguishable from each other within analytical uncertainty. The mineral chemistries, O-isotopic data, and textural relationships indicate that the olivine inclusions were produced at a temperature greater than 800 C. It is unlikely that the olivines formed during the same event that gave rise to the carbonates in ALH 84001, which have more elevated and variable delta(sup 18)O values, and were probably formed from fluids that were not in isotopic equilibrium with the orthopyroxene or olivine The reactions most likely instrumental in the formation of olivine could be either the dehydration of hydrous silicates that formed during carbonate precipitation or the reduction of orthopyroxene and spinel If the olivine was formed by either reaction during a postcarbonate beating event, the implications are profound with regards to the interpretations of McKay et al. Due to the low diffusion rates in carbonates, this rapid, high-temperature event would have resulted in the preservation of the fine-scale carbonate zoning' while partially devolatilizing select carbonate compositions on a submicrometer scale. This may have resulted in the formation of the minute magnetite grains that McKay et al attributed to biogenic activity.

  3. Sulfur isotopic systematics in alteration assemblages in martian meteorite Allan Hills 84001

    SciTech Connect

    Shearer, C.K.; Layne, G.D.; Papike, J.J.; Spilde, M.N.

    1996-08-01

    ALH84001 is a coarse-grained, clastic orthopyroxenite meteorite related to the SNC meteorite group (shergottites, nakhlites, Chassigny). Superimposed upon the orthopyroxene-dominant igneous mineral assemblage is a hydrothermal signature. This hydrothermal overprint consists of carbonate assemblages occurring in spheroidal aggregates and fine-grained carbonate-sulfide vug-filling. The sulfide in this assemblage has been identified as pyrite, an unusual sulfide in meteorites. Previously, Burgess et al. (1989) reported a bulk {delta} {sup 34}S for a SNC group meteorite (Shergotty) of -0.5 {+-} 1.5%. Here, we report the first martian {delta} {sup 34}S values from individual sulfide grains. Using newly developed ion microprobe techniques, we were able to determine {delta} {sup 34}S of the pyrite in ALH84001 with a 1 {alpha} precision of better than {+-}0.5%. The {delta} {sup 34}S values for the pyrite range from +4.8 to +7.8%. Within the stated uncertainties, the pyrite from ALH84001 exhibits a real variability in {delta} {sup 34}S in this alteration assemblage. In addition, these sulfides are demonstrably enriched in {sup 34}S relative to Canon Diablo troilite and sulfides from most other meteorites. This signature implies that the planetary body represented by ALH 84001 experienced processes capable of fractionating sulphur isotopes and that hydrothermal conditions changed during pyrite precipitation (T, pH, fluid composition, etc.). These new data are not consistent with the pyrite recording either biogenic activity or atmospheric fractionation of sulphur through nonthermal escape mechanisms or oxidation processes. This study also demonstrates the usefulness of ion microprobe measurements of sulphur isotopes in constraining conditions on other planetary bodies.

  4. Sulfur isotopic systematics in alteration assemblages in martian meteorite Allan Hills 84001

    NASA Astrophysics Data System (ADS)

    Shearer, C. K.; Layne, G. D.; Papike, J. J.; Spilde, M. N.

    1996-08-01

    ALH84001 is a coarse-grained, clastic orthopyroxenite meteorite related to the SNC meteorite group ( shergottites, nakhlites, Chassigny). Superimposed upon the orthopyroxene-dominant igneous mineral assemblage is a hydrothermal signature. This hydrothermal overprint consists of carbonate assemblages occurring in spheroidal aggregates and fine-grained carbonate-sulfide vug-filling. The sulfide in this assemblage has been identified as pyrite, an unusual sulfide in meteorites. Previously, Burgess et al. (1989) reported a bulk δ 34S for a SNC group meteorite (Shergotty) of -0.5 ± 1.5‰. Here, we report the first martian δ 34S values from individual sulfide grains. Using newly developed ion microprobe techniques, we were able to determine δ 34S of the pyrite in ALH84001 with a 1 a precision of better than ±0.5‰. The δ 34S values for the pyrite range from +4.8 to +7.8‰. Within the stated uncertainties, the pyrite from ALH84001 exhibits a real variability in δ 34S in this alteration assemblage. In addition, these sulfides are demonstrably enriched in 34S relative to Canon Diablo troilite and sulfides from most other meteorites. This signature implies that the planetary body represented by ALH84001 experienced processes capable of fractionating sulphur isotopes and that hydrothermal conditions changed during pyrite precipitation (T, pH, fluid composition, etc.). The fractionated signature of the sulphur in the pyrite is most likely attributed to either conditions of pyrite precipitation (low temperature, reduced (low fo 2) and moderately alkaline (pH > 8) environment) or enrichment of fluids in 34S by surface processes (weathering or impact processes) prior to precipitation. These new data are not consistent with the pyrite recording either biogenic activity or atmospheric fractionation of sulphur through nonthermal escape mechanisms or oxidation processes. This study also demonstrates the usefulness of ion microprobe measurements of sulphur isotopes in

  5. Carbonates in the Martian meteorite Allan Hills 84001 formed at 18 ± 4 °C in a near-surface aqueous environment

    PubMed Central

    Halevy, Itay; Fischer, Woodward W.; Eiler, John M.

    2011-01-01

    Despite evidence for liquid water at the surface of Mars during the Noachian epoch, the temperature of early aqueous environments has been impossible to establish, raising questions of whether the surface of Mars was ever warmer than today. We address this problem by determining the precipitation temperature of secondary carbonate minerals preserved in the oldest known sample of Mars’ crust—the approximately 4.1 billion-year-old meteorite Allan Hills 84001 (ALH84001). The formation environment of these carbonates, which are constrained to be slightly younger than the crystallization age of the rock (i.e., 3.9 to 4.0 billion years), has been poorly understood, hindering insight into the hydrologic and carbon cycles of earliest Mars. Using “clumped” isotope thermometry we find that the carbonates in ALH84001 precipitated at a temperature of approximately 18 °C, with water and carbon dioxide derived from the ancient Martian atmosphere. Furthermore, covarying carbonate carbon and oxygen isotope ratios are constrained to have formed at constant, low temperatures, pointing to deposition from a gradually evaporating, subsurface water body—likely a shallow aquifer (meters to tens of meters below the surface). Despite the mild temperatures, the apparently ephemeral nature of water in this environment leaves open the question of its habitability. PMID:21969543

  6. Carbonates in the Martian meteorite Allan Hills 84001 formed at 18 +/- 4 degrees C in a near-surface aqueous environment.

    PubMed

    Halevy, Itay; Fischer, Woodward W; Eiler, John M

    2011-10-11

    Despite evidence for liquid water at the surface of Mars during the Noachian epoch, the temperature of early aqueous environments has been impossible to establish, raising questions of whether the surface of Mars was ever warmer than today. We address this problem by determining the precipitation temperature of secondary carbonate minerals preserved in the oldest known sample of Mars' crust--the approximately 4.1 billion-year-old meteorite Allan Hills 84001 (ALH84001). The formation environment of these carbonates, which are constrained to be slightly younger than the crystallization age of the rock (i.e., 3.9 to 4.0 billion years), has been poorly understood, hindering insight into the hydrologic and carbon cycles of earliest Mars. Using "clumped" isotope thermometry we find that the carbonates in ALH84001 precipitated at a temperature of approximately 18 °C, with water and carbon dioxide derived from the ancient Martian atmosphere. Furthermore, covarying carbonate carbon and oxygen isotope ratios are constrained to have formed at constant, low temperatures, pointing to deposition from a gradually evaporating, subsurface water body--likely a shallow aquifer (meters to tens of meters below the surface). Despite the mild temperatures, the apparently ephemeral nature of water in this environment leaves open the question of its habitability. PMID:21969543

  7. Carbonates in the Martian meteorite Allan Hills 84001 formed at 18 +/- 4 degrees C in a near-surface aqueous environment.

    PubMed

    Halevy, Itay; Fischer, Woodward W; Eiler, John M

    2011-10-11

    Despite evidence for liquid water at the surface of Mars during the Noachian epoch, the temperature of early aqueous environments has been impossible to establish, raising questions of whether the surface of Mars was ever warmer than today. We address this problem by determining the precipitation temperature of secondary carbonate minerals preserved in the oldest known sample of Mars' crust--the approximately 4.1 billion-year-old meteorite Allan Hills 84001 (ALH84001). The formation environment of these carbonates, which are constrained to be slightly younger than the crystallization age of the rock (i.e., 3.9 to 4.0 billion years), has been poorly understood, hindering insight into the hydrologic and carbon cycles of earliest Mars. Using "clumped" isotope thermometry we find that the carbonates in ALH84001 precipitated at a temperature of approximately 18 °C, with water and carbon dioxide derived from the ancient Martian atmosphere. Furthermore, covarying carbonate carbon and oxygen isotope ratios are constrained to have formed at constant, low temperatures, pointing to deposition from a gradually evaporating, subsurface water body--likely a shallow aquifer (meters to tens of meters below the surface). Despite the mild temperatures, the apparently ephemeral nature of water in this environment leaves open the question of its habitability.

  8. An abiotic origin for hydrocarbons in the Allan Hills 84001 martian meteorite through cooling of magmatic and impact-generated gases

    NASA Technical Reports Server (NTRS)

    Shock, E. L.

    2000-01-01

    Thermodynamic calculations of metastable equilibria were used to evaluate the potential for abiotic synthesis of aliphatic and polycyclic aromatic hydrocarbons (PAHs) in the martian meteorite Allan Hills (ALH) 84001. The calculations show that PAHs and normal alkanes could form metastably from CO, CO2, and H2 below approximately 250-300 degrees C during rapid cooling of trapped magmatic or impact-generated gases. Depending on temperature, bulk composition, and oxidation-reduction conditions, PAHs and normal alkanes can form simultaneously or separately. Moreover, PAHs can form at lower H/C ratios, higher CO/CO2 ratios, and higher temperatures than normal alkanes. Dry conditions with H/C ratios less than approximately 0.01-0.001 together with high CO/CO2 ratios also favor the formation of unalkylated PAHs. The observed abundance of PAHs, their low alkylation, and a variable but high aromatic to aliphatic ratio in ALH 84001 all correspond to low H/C and high CO/CO2 ratios in magmatic and impact gases and can be used to deduce spatial variations of these ratios. Some hydrocarbons could have been formed from trapped magmatic gases, especially if the cooling was fast enough to prevent reequilibration. We propose that subsequent impact heating(s) in ALH 84001 could have led to dissociation of ferrous carbonates to yield fine-grain magnetite, formation of a CO-rich local gas phase, reduction of water vapor to H2, reequilibration of the trapped magmatic gases, aromatization of hydrocarbons formed previously, and overprinting of the synthesis from magmatic gases, if any. Rapid cooling and high-temperature quenching of CO-, H2-rich impact gases could have led to magnetite-catalyzed hydrocarbon synthesis.

  9. Mineralization of Bacteria in Terrestrial Basaltic Rocks: Comparison With Possible Biogenic Features in Martian Meteorite Allan Hills 84001

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, K. L.; McKay, D. S.; Wentworth, S. J.; Stevens, T. O.; Taunton, A. E.; Allen, C. C.; Gibson, E. K., Jr.; Romanek, C. S.

    1998-01-01

    The identification of biogenic features altered by diagenesis or mineralization is important in determining whether specific features in terrestrial rocks and in meteorites may have a biogenic origin. Unfortunately, few studies have addressed the formation of biogenic features in igneous rocks, which may be important to these phenomena, including the controversy over possible biogenic features in basaltic martian meteorite ALH84001. To explore the presence of biogenic features in igneous rocks, we examined microcosms growing in basaltic small-scale experimental growth chambers or microcosms. Microbial communities were harvested from aquifers of the Columbia River Basalt (CRB) group and grown in a microcosm containing unweathered basalt chips and groundwater (technique described in. These microcosms simulated natural growth conditions in the deep subsurface of the CRB, which should be a good terrestrial analog for any putative martian subsurface ecosystem that may have once included ALH84001. Here we present new size measurements and photomicrographs comparing the putative martian fossils to biogenic material in the CRB microcosms. The range of size and shapes of the biogenic features on the CRB microcosm chips overlaps with and is similar to those on ALH84001 chips. Although this present work does not provide evidence for the biogenicity of ALH84001 features, we believe that, based on criteria of size, shape, and general morphology, a biogenic interpretation for the ALH84001 features remains plausible.

  10. Possible Meteorites in the Martian Hills

    NASA Technical Reports Server (NTRS)

    2006-01-01

    From its winter outpost at 'Low Ridge' inside Gusev Crater, NASA's Mars Exploration Rover Spirit took this spectacular, color mosaic of hilly, sandy terrain and two potential iron meteorites. The two light-colored, smooth rocks about two-thirds of the way up from the bottom of the frame have been labeled 'Zhong Shan' and 'Allan Hills.'

    The two rocks' informal names are in keeping with the rover science team's campaign to nickname rocks and soils in the area after locations in Antarctica. Zhong Shang is an Antarctic base that the People's Republic of China opened on Feb. 26, 1989, at the Larsemann Hills in Prydz Bay in East Antarctica. Allan Hills is a location where researchers have found many Martian meteorites, including the controversial ALH84001, which achieved fame in 1996 when NASA scientists suggested that it might contain evidence for fossilized extraterrestrial life. Zhong Shan was the given name of Dr. Sun Yat-sen (1866-1925), known as the 'Father of Modern China.' Born to a peasant family in Guangdong, Sun moved to live with his brother in Honolulu at age 13 and later became a medical doctor. He led a series of uprisings against the Qing dynasty that began in 1894 and eventually succeeded in 1911. Sun served as the first provisional president when the Republic of China was founded in 1912.

    The Zhong Shan and Allan Hills rocks, at the left and right, respectively, have unusual morphologies and miniature thermal emission spectrometer signatures that resemble those of a rock known as 'Heat Shield' at the Meridiani site explored by Spirit's twin, Opportunity. Opportunity's analyses revealed Heat Shield to be an iron meteorite.

    Spirit acquired this approximately true-color image on the rover's 872nd Martian day, or sol (June 16, 2006), using exposures taken through three of the panoramic camera's filters, centered on wavelengths of 600 nanometers, 530 nanometers, and 480 nanometers.

  11. Uranium series dating of Allan Hills ice

    NASA Astrophysics Data System (ADS)

    Fireman, E. L.

    1986-03-01

    Uranium-238 decay series nuclides dissolved in Antarctic ice samples were measured in areas of both high and low concentrations of volcanic glass shards. Ice from the Allan Hills site (high shard content) had high Ra-226, Th-230 and U-234 activities but similarly low U-238 activities in comparison with Antarctic ice samples without shards. The Ra-226, Th-230 and U-234 excesses were found to be proportional to the shard content, while the U-238 decay series results were consistent with the assumption that alpha decay products recoiled into the ice from the shards. Through this method of uranium series dating, it was learned that the Allen Hills Cul de Sac ice is approximately 325,000 years old.

  12. Uranium series dating of Allan Hills ice

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.

    1986-01-01

    Uranium-238 decay series nuclides dissolved in Antarctic ice samples were measured in areas of both high and low concentrations of volcanic glass shards. Ice from the Allan Hills site (high shard content) had high Ra-226, Th-230 and U-234 activities but similarly low U-238 activities in comparison with Antarctic ice samples without shards. The Ra-226, Th-230 and U-234 excesses were found to be proportional to the shard content, while the U-238 decay series results were consistent with the assumption that alpha decay products recoiled into the ice from the shards. Through this method of uranium series dating, it was learned that the Allen Hills Cul de Sac ice is approximately 325,000 years old.

  13. A comparison of the iddingsite alteration products in two terrestrial basalts and the Allan Hills 77005 martian meteorite using Raman spectroscopy and electron microprobe analyses

    NASA Astrophysics Data System (ADS)

    Kuebler, Karla E.

    2013-04-01

    We document the secondary mineral assemblages in two occurrences of terrestrial iddingsite, Lunar Crater, Nevada (LC) and Mauna Kea, Hawaii (MK), and compare these with the iddingsite in Allan Hills (ALHA) 77005. Short Raman spectroscopic traverses across olivine alteration fronts provide information about changes in mineralogy with alteration. Data from the Raman traverses are combined with electron microprobe (EMP) traverses at the same locations which provide information regarding element mobility and confirm mineral identifications made by Raman spectroscopy. This information is used with petrographic observations to argue for the martian origin of the iddingsite and jarosite, infer the sequence of alteration, and deliberate on the conditions and settings of alteration. Raman spectra indicate the presence of different iron oxides/oxyhydroxides in each sample (goethite in LC, maghemite in MK, and akaganéite in ALHA), and the terrestrial samples show different element mobility trends (loss of MgO and SiO2, retention of FeO) than ALHA (loss of MgO and FeO, influx of SiO2), whose trends reflect the deposition of jarosite. Altered olivine occur throughout the LC samples but only in the exteriors of the MK samples. The LC and MK alteration products formed by surface alteration, but ALHA 77005 is a lherzolite, and the olivine hosting the iddingsite are enclosed by orthopyroxene (appear to be restricted to the light lithology), suggesting that it formed at depth during magma consolidation. The ALHA iddingsite is an example of "deuteric alteration" (reaction with fluids that separated from the magma as crystallization progressed towards completion).

  14. A new kind of primitive chondrite, Allan Hills 85085

    NASA Technical Reports Server (NTRS)

    Scott, Edward R. D.

    1988-01-01

    Allan Hills (ALH) 85085, a chemically and mineralogically unique chondrite whose components have suffered little metamorphism or alteration, is discussed. It is found that ALH 85085 has 4 wt pct chondrules (mean diameter 16 microns), 36 wt pct Fe, Ni, 56 wt pct lithic and mineral silicate fragments, and 2 wt pct trolite. It is suggested that, with the exception of matrix lumps, the components of ALH 85085 formed and accreted in the solar nebula. It is shown that ALH 85085 does not belong to any of the nine chondrite groups and is very different from Kakangari. Similarities between ALH 85085 and Bencubbin and Weatherford suggest that the latter two primitive meteorites may be chondrites with high metal abundances and very large, partly fragmented chondrules.

  15. The history of Allan Hills 84001 revised: multiple shock events.

    PubMed

    Treiman, A H

    1998-07-01

    The geologic history of Martian meteorite Allan Hills (ALH) 84001 is more complex than previously recognized, with evidence for four or five crater-forming impacts onto Mars. This history of repeated deformation and shock metamorphism appears to weaken some arguments that have been offered for and against the hypothesis of ancient Martian life in ALH 84001. Allan Hills 84001 formed originally from basaltic magma. Its first impact event (I1) is inferred from the deformation (D1) that produced the granular-textured bands ("crush zones") that transect the original igneous fabric. Deformation D1 is characterized by intense shear and may represent excavation or rebound flow of rock beneath a large impact crater. An intense thermal metamorphism followed D1 and may be related to it. The next impact (I2) produced fractures, (Fr2) in which carbonate "pancakes" were deposited and produced feldspathic glass from some of the igneous feldspars and silica. After I2, carbonate pancakes and globules were deposited in Fr2 fractures and replaced feldspathic glass and possibly crystalline silicates. Next, feldspars, feldspathic glass, and possibly some carbonates were mobilized and melted in the third impact (I3). Microfaulting, intense fracturing, and shear are also associated with I3. In the fourth impact (I4), the rock was fractured and deformed without significant heating, which permitted remnant magnetization directions to vary across fracture surfaces. Finally, ALH 84001 was ejected from Mars in event I5, which could be identical to I4. This history of multiple impacts is consistent with the photogeology of the Martian highlands and may help resolve some apparent contradictions among recent results on ALH 84001. For example, the submicron rounded magnetite grains in the carbonate globules could be contemporaneous with carbonate deposition, whereas the elongate magnetite grains, epitaxial on carbonates, could be ascribed to vapor-phase deposition during I3. PMID:11543074

  16. Noble gases in twenty Yamato H-chondrites: Comparison with Allan Hills chondrites and modern falls

    NASA Technical Reports Server (NTRS)

    Loeken, TH.; Scherer, P.; Schultz, L.

    1993-01-01

    Concentration and isotopic composition of noble gases have been measured in 20 H-chrondrites found on the Yamato Mountains ice fields in Antarctica. The distribution of exposure ages as well as of radiogenic He-4 contents is similar to that of H-chrondrites collected at the Allan Hills site. Furthermore, a comparison of the noble gas record of Antarctic H-chrondrites and finds or falls from non-Antarctic areas gives no support to the suggestion that Antarctic H-chrondrites and modern falls derive from differing interplanetary meteorite populations.

  17. Possible Meteorites in the Martian Hills (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    From its winter outpost at 'Low Ridge' inside Gusev Crater, NASA's Mars Exploration Rover Spirit took this spectacular, color mosaic of hilly, sandy terrain and two potential iron meteorites. The two light-colored, smooth rocks about two-thirds of the way up from the bottom of the frame have been labeled 'Zhong Shan' and 'Allan Hills.'

    The two rocks' informal names are in keeping with the rover science team's campaign to nickname rocks and soils in the area after locations in Antarctica. Zhong Shang is an Antarctic base that the People's Republic of China opened on Feb. 26, 1989, at the Larsemann Hills in Prydz Bay in East Antarctica. Allan Hills is a location where researchers have found many Martian meteorites, including the controversial ALH84001, which achieved fame in 1996 when NASA scientists suggested that it might contain evidence for fossilized extraterrestrial life. Zhong Shan was the given name of Dr. Sun Yat-sen (1866-1925), known as the 'Father of Modern China.' Born to a peasant family in Guangdong, Sun moved to live with his brother in Honolulu at age 13 and later became a medical doctor. He led a series of uprisings against the Qing dynasty that began in 1894 and eventually succeeded in 1911. Sun served as the first provisional president when the Republic of China was founded in 1912.

    The Zhong Shan and Allan Hills rocks, at the left and right, respectively, have unusual morphologies and miniature thermal emission spectrometer signatures that resemble those of a rock known as 'Heat Shield' at the Meridiani site explored by Spirit's twin, Opportunity. Opportunity's analyses revealed Heat Shield to be an iron meteorite.

    Spirit acquired this false-color image on the rover's 872nd Martian day, or sol (June 16, 2006), using exposures taken through three of the panoramic camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers. The image is presented in false color to emphasize differences among

  18. Petrogenetic relationship between Allan Hills 77005 and other achondrites

    NASA Technical Reports Server (NTRS)

    Mcsween, H. Y., Jr.; Taylor, L. A.; Stolper, E. M.; Muntean, R. A.; Okelley, G. D.; Eldridge, J. S.; Biswas, S.; Ngo, H. T.; Lipschutz, M. E.

    1979-01-01

    The paper presents chemical and petrologic data relating the Allan Hills (ALHA) 77005 achondrite from Antarctica and explores their petrogenetic relationship with the shergottites. Petrologic similarities with the latter in terms of mineralogy, oxidation state, inferred source region composition, and shock ages suggest a genetic relationship, also indicated by volatile to involatile element ratios and abundances of other trace elements. ALHA 77005 may be a cumulate crystallized from a liquid parental to materials from which the shergottites crystallized or a sample of peridotite from which shergottite parent liquids were derived. Chemical similarities with terrestrial ultramafic rocks suggest that it provides an additional sample of the only other solar system body with basalt source origins chemically similar to the upper earth mantle.

  19. Allan Hills 88019: an Antarctic H-chondrite with a very long terrestrial age.

    NASA Astrophysics Data System (ADS)

    Scherer, P.; Schultz, L.; Neupert, U.; Knauer, M.; Neumann, S.; Leya, I.; Michel, R.; Mokos, J.; Lipschutz, M. E.; Metzler, K.; Suter, M.; Kubik, P. W.

    1997-11-01

    We have measured the concentrations of the cosmogenic radionuclides 10Be, 26Al and 36Cl (half-lives 1.51 Ma, 716 ka, 300 ka, respectively) in two different laboratories by AMS techniques, as well as concentrations and isotopic compositions of stable helium, neon and argon in the Antarctic H-chondrite Allan Hills 88019. In addition, nuclear track densities were measured. From these results it is concluded that the meteoroid ALH 88019 had a pre-atmospheric radius of (20 ( 5) cm and a shielding depth for the analyzed samples of between 4 and 8 cm. Using calculated and experimentally determined production rates of cosmogenic nuclides, an exposure age of about 40 Ma is obtained from cosmogenic 21Ne and 38Ar. The extremely low concentrations of radionuclides are explained by a very long terrestrial age for this meteorite of (2.2 ( 0.4) Ma. A similarly long terrestrial age was found so far only for the Antarctic L-chondrite Lewis Cliff 86360. Such long ages establish one boundary condition for the history of meteorites in Antarctica.

  20. Antarctic Meteorite Location Map Series

    NASA Technical Reports Server (NTRS)

    Schutt, John (Editor); Fessler, Brian (Editor); Cassidy, William (Editor)

    1989-01-01

    Antarctica has been a prolific source of meteorites since meteorite concentrations were discovered in 1969. The Antarctic Search For Meteorites (ANSMET) project has been active over much of the Trans-Antarctic Mountain Range. The first ANSMET expedition (a joint U.S.-Japanese effort) discovered what turned out to be a significant concentration of meteorites at the Allan Hills in Victoria Land. Later reconnaissance in this region resulted in the discovery of meteorite concentrations on icefields to the west of the Allan Hills, at Reckling Moraine, and Elephant Moraine. Antarctic meteorite location maps (reduced versions) of the Allan Hills main, near western, middle western, and far western icefields and the Elephant Moraine icefield are presented. Other Antarctic meteorite location maps for the specimens found by the ANSMET project are being prepared.

  1. Compositions of Three Lunar Meteorites: Meteorite Hills 01210, Northeast Africa 001, and Northwest Africa 3136

    NASA Technical Reports Server (NTRS)

    Korotev, R. L.; Irving, A. J.

    2005-01-01

    We report on compositions obtained by instrumental neutron activation analysis on three new lunar meteorites, MET 01210 (Meteorite Hills, Antarctica; 23 g), NEA 001 (Northeast Africa, Sudan; 262 g), and NWA 3136 (Northwest Africa, Algeria or Morocco; 95 g). As in previous similar studies, we divided our samples into many (8-9) small (approximately 30 mg) subsamples prior to analysis.

  2. Rubidium-Strontium Formation Age of Allan Hills 84001 Carbonates

    NASA Technical Reports Server (NTRS)

    Borg, L. E.; Nyquist, L. E.; Shih, C.-Y.; Weismann, H.; Reese, Y.; Connelly, J. N.

    1998-01-01

    Our preferred age for the formation of carbonates in the martian meteorite ALH 84001 is 3.90 plus or minus 0.04 Ga for Lambda (Rubidium 87) equals 0.01402 Ga (exp -1), or 3.85 plus or minus 0.04 Ga for Lambda (Rubidium 87) = 0.0142 Ga(exponent -1). This age is determined by a three-point Rb-Sr isochron defined by leachates of high-graded carbonate-rich material. Major cation and especially phosphorous analyses of the leachates permit contributions from igneous whitlockite to be recognized for low-acidity leachates, and the corresponding data are omitted from the isochron. Data for the two highest acidity leachates plot close to the preferred isochron, but are omitted because we believe they contain contributions leached from the pyroxene substrate on which most of the carbonates are found. Nevertheless, the isochron age for all five highest-acidity leachates is 3.94 plus or minus 0.04 Ga, and is within error of the age obtained for the more restricted data set. All leachates used to define the isochron have major cation compositions that are singular to those obtained by microprobe analyses of the carbonate rosettes and are consistent with progressive digestion of the carbonates according to their composition. The age thus obtained for the carbonates is about 600 m.y. younger than the crystalization age of ALH 84001 determined by Sm-Nd analyses but is within error limits of the age of impact metamorphism inferred from the Rb-Sr and Ar-Ar systematics of silicates. which yield ages of 3.85 plus or minus 0.05 Ga and 4.05- 3.80 Ga to 4.3-3.8 Ga, respectively. Similarities between the carbonate crystallization age and the age of impact metamorphism as determined by Ar-Ar and Rb-Sr suggest that the carbonate formation is impact-related. Nevertheless, both high and low- temperature scenarios for the origin of the carbonates are possible.

  3. Radioactivities in returned lunar materials and in meteorites

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.

    1984-01-01

    Carbon 14 terrestial ages were determined with low level minicomputers and accelerator mass spectrometry on 1 Yamato and 18 Allan Hills and nearby sited meteorites. Techniques for an accelerator mass spectrometer which make C(14) measurements on small samples were developed. Also Be(10) concentrations were measured in Byrd core and Allan Hills ice samples.

  4. Meteorites and microbes: meteorite collection and ice sampling at Patriot Hills, Thiel Mountains, and South Pole, Antarctica

    NASA Astrophysics Data System (ADS)

    Sipiera, Paul P.; Hoover, Richard B.; Jerman, Gregory A.

    2000-12-01

    In 1998, the Patriot Hills area of the Ellsworth Mountains of Antarctica was selected by the Planetary Studies Foundation (PSF) of Algonquin, Illinois USA as a potential site for the collection of meteorites. The eight person expedition searched several sites in and around the Patriot Hills, but met with little success in finding meteorites. In January 2000, the PSF chose to continue its efforts in the Thiel Mountains, an area of known meteorite concentrations. The goal was to collect as many meteorites as possible by extending the previously searched blue ice areas at the Moulton Escarpment. Earlier search teams collectively recovered 36 meteorites. In the five days of fieldwork at the Moulton Escarpment, the PSF team collected 19 confirmed stone meteorites, and 2 possible achondrites. Upon return to Patriot Hills another small stone meteorite, consisting of 6 small fragments totalling 1.7 grams, was collected in the Morris Moraine where a 23 mg meteorite fragment was found in 1998. In addition, ice samples were collected at Patriot Hills, Thiel Mountains, and the South Pole. The presence of several micro-organisms has been identified in these samplings and will be evaluated as possible contaminants of Antarctic meteorites.

  5. A nitrogen and argon stable isotope study of Allan Hills 84001: implications for the evolution of the Martian atmosphere.

    PubMed

    Grady, M M; Wright, I P; Pillinger, C T

    1998-07-01

    The abundances and isotopic compositions of N and Ar have been measured by stepped combustion of the Allan Hills 84001 (ALH 84001) Martian orthopyroxenite. Material described as shocked is N-poor ([N] approximately 0.34 ppm; delta 15N approximately +23%); although during stepped combustion, 15N-enriched N (delta 15N approximately +143%) is released in a narrow temperature interval between 700 degrees C and 800 degrees C (along with 13C-enriched C (delta 13C approximately +19%) and 40Ar). Cosmogenic species are found to be negligible at this temperature; thus, the isotopically heavy component is identified, in part, as Martian atmospheric gas trapped relatively recently in the history of ALH84001. The N and Ar data show that ALH84001 contains species from the Martian lithosphere, a component interpreted as ancient trapped atmosphere (in addition to the modern atmospheric species), and excess 40Ar from K decay. Deconvolution of radiogenic 40Ar from other Ar components, on the basis of end-member 36Ar/14N and 40Ar/36Ar ratios, has enabled calculation of a K-Ar age for ALH 84001 as 3.5-4.6 Ga, depending on assumed K abundance. If the component believed to be Martian palaeoatmosphere was introduced to ALH 84001 at the time the K-Ar age was set, then the composition of the atmosphere at this time is constrained to: delta 15N > or = +200%, 40Ar/36Ar < or = 3000 and 36Ar/14N > or = 17 x 10(-5). In terms of the petrogenetic history of the meteorite, ALH 84001 crystallised soon after differentiation of the planet, may have been shocked and thermally metamorphosed in an early period of bombardment, and then subjected to a second event. This later process did not reset the K-Ar system but perhaps was responsible for introducing (recent) atmospheric gases into ALH 84001; and it might mark the time at which ALH 84001 suffered fluid alteration resulting in the formation of the plagioclase and carbonate mineral assemblages. PMID:11543078

  6. Meteorites and Microbes: Meteorite Collection and Ice Sampling at Patriot Hills, Thiel Mountains, and South Pole, Antarctica

    NASA Technical Reports Server (NTRS)

    Sipiera, Paul P.; Hoover, Richard B.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    During the Antarctica 2000 Expedition, sponsored by the Planetary Studies Foundation, meteorites and ice microbiota were collected from the Patriot Hills, and Thiel Mountains of Antarctica and snow samples were at the South Pole. Psychrophilic and psychrotrophic microbiota were obtained from blue ice, cryoconite and ice-bubble systems. Twenty frozen meteorites were collected using aseptic techniques from the blue ice fields near the Moulton Escarpment of the Thiel Mountains (85 S, 94 W) and from the Morris Moraine of the Patriot Hills (80 S, 81 W) Ellsworth Mountains. These ice and meteorite samples are of potential significance to Astrobiology. They may help refine chemical and morphological biomarkers and refine characteristics of microbial life in one of the harshest environments on Earth. We discuss the Antarctica 2000 Expedition and provide preliminary results of the investigation of the meteorites and ice microbiota recovered.

  7. Over 5,600 Japanese collection of Antarctic meteorites: Recoveries, curation and distribution

    NASA Technical Reports Server (NTRS)

    Yanai, K.; Kojima, H.

    1986-01-01

    The history of recovery of meteorite fragments in the Yamato Mountains, Allan Hills, and Victoria Land, Antarctica is reviewed. The Japanese collection of Antarctic meteorites were numbered, weighed, photographed, identified, and classified. Sample distribution of the Japanese Antarctic meteorites is described.

  8. The Natural Thermoluminescence Survey of Antarctic Meteorites: Ordinary Chondrites at the Grosvenor Mountains, Macalpine Hills, Pecora Escarpment and Queen Alexandra Range, and New Data for the Elephant Moraine, Ice Fields

    NASA Technical Reports Server (NTRS)

    Benoit, Paul H.; Sears, Derek W. G.

    1999-01-01

    The natural TL (Thermoluminescence) survey of Antarctic meteorites was started in 1987 at the request of the Antarctic Meteorite Working Group in order to provide an initial description of radiation and thermal histories. It was intended to be a complement to the mineralogical and petrographic surveys performed at the Johnson Space Center and the Smithsonian Institution. All ANSMET (Antarctic Search for Meteorites) samples recovered since then, besides those that were heated throughout by atmospheric passage, have been measured. To date this amounts to about 1200 samples. As the data for each ice field reaches a significant level, we have been conducting a thorough examination of the data for that field with a view to identifying pairing, providing an estimate of terrestrial age and residence time on the ice surface, looking for differences in natural TL between ice fields, looking for variations in natural TL level with location on the ice, looking for meteorites with natural TL levels outside the normal range. Pairing is a necessary first step in ensuring the most productive use of the collection, while geographical variations could perhaps provide clues to concentration mechanisms. Samples with natural TL values outside the normal range are usually inferred to have had either small perihelia or recent changes in orbital elements. In addition, induced TL data have enabled us to look for evidence for secular variation in the nature of the flux of meteorites to Earth, and look for petrologically unusual meteorites, such as particularly primitive ordinary chondrites, heavily shocked meteorites, or otherwise anomalous meteorites. To date we have published studies of the TL properties of 167 ordinary chondrites from Allan Hills, 107 from Elephant Moraine and 302 from Lewis Cliff and we have discussed the TL properties of fifteen H chondrites collected at the Allan Hills by Euromet after a storm during the 1988 season. We now have additional databases for a reasonable

  9. Terrestrial ages of Antarctic meteorites: Implications for concentration mechanisms

    NASA Technical Reports Server (NTRS)

    Schultz, L.

    1986-01-01

    Antarctic meteorites differ from meteorites fallen in other places in their mean terrestrial ages. Boeckl estimated the terrestrial half-life for the disintegration of stone meteorites by weathering under the climatic conditions of the Western United States to be about 3600 years. Antarctic meteorites, however, have terrestrial ages up to 70000 years, indicating larger weathering half-lives. The terrestrial ages of meteorites are determined by their concentration of cosmic-ray-produced radionuclides with suitable half-lives (C-14, Al-26, and Cl-36). These radionuclides have yielded reliable ages for the Antarctic meteorites. The distribution of terrestrial ages of Allan Hills and Yamato meteorites are examined.

  10. The Natural Thermoluminescence Survey of Antarctic Meteorites: Ordinary Chondrites at the Grosvenor Mountains, MacAlpine Hills, Pecora Escarpment and Queen Alexandra Range, and New Data New Data for the Elephant Moraine, Ice Fields

    NASA Technical Reports Server (NTRS)

    Benoit, Paul H.; Sears, Derek W. G.

    2000-01-01

    The natural TL survey of Antarctic meteorites was started in 1987 at the request of the Antarctic Meteorite Working Group in order to provide an initial description of radiation and thermal histories. It was intended to be a complement to the mineralogical and petrographic surveys performed at the Johnson Space Center and the Smithsonian Institution. All ANSMET samples recovered since then, besides those that were heated throughout by atmospheric passage, have been measured. To date this amounts to about 1200 samples. As the data for each ice field reaches a significant level, we have been conducting a thorough examination of the data for that field with a view to (1) identifying pairing, (2) providing an estimate of terrestrial age and residence time on the ice surface, (3) looking for differences in natural TL between ice fields, (4) looking for variations in natural TL level with location on the ice, (5) looking for meteorites with natural TL levels outside the normal range. Pairing is a necessary first step in ensuring the @ost productive use of the collection, while geographical variations could perhaps provide clues to concentration mechanisms. Samples with natural TL values outside the normal range are usually inferred to have had either small perihelia or recent changes in orbital elements. In addition, induced TL data have enabled us to (5) look for evidence for secular variation in the nature of the flux of meteorites to Earth, and (6) look for petrologically unusual meteorites, such as particularly primitive ordinary chondrites, heavily shocked meteorites, or otherwise anomalous meteorites. To date we have published studies of the TL properties of 167 ordinary chondrites from Allan Hills, 107 from Elephant Moraine and 302 from Lewis Cliff and we have discussed the TL properties of fifteen H chondrites collected at the Allan Hills by Euromet after a storm during the 1988 season. We now have additional databases for a reasonable number of ordinary

  11. Meteorites and the Antarctic ice sheet

    NASA Technical Reports Server (NTRS)

    Cassidy, W. A.

    1986-01-01

    The majority of the meteorite finds were located in the Allan Hills site. All the expected goals involving the recovery of rare or previously unknown types of meteorites, and even the recovery of lunar ejecta, were realized. The relationship between these remarkable concentrations of meteorites and the Antarctic ice sheet itself were less well documented. Ice flow vector studies were made and concentration models were proposed. Earlier estimates of the abundances of meteorite types were based on the number of falls in the world collections. The accumulated data and the future collected data will allow more reliable estimates of the source region of most meteorites.

  12. PYTi-NiCr Signatures in the Columbia Hills are Present in Certain Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Clark, B. C.; Gellert, R.; Ming, D. W.; Morris, R. V.; Mittlefehldt, D. W.; Squyres, S. W.

    2006-01-01

    Uniquely high levels of phosphorus and titanium were observed in several samples [1-3] by the APXS x-ray fluorescence measurements as the MER Spirit rover climbed Husband Hill (Columbia Hills, Gusev crater, Mars). A careful study of many such samples and their geochemical variability has revealed additional elements in this pattern, and that the derived multi-element signature is also unambiguously manifested in several martian meteorites.

  13. MacAlpine Hills 88104 and 88105 lunar highland meteorites: General description and consortium overview

    SciTech Connect

    Lindstrom, M.M. ); Schwarz, C.; Score, R. ); Mason, B. )

    1991-11-01

    MacAlpine Hills 88104 and 88105 are new lunar meteorites returned from Antarctica by the 1988-1989 US meteorite collection team. The two specimens were found in nearby locations and, based on field and laboratory evidence, are thought to be pieces of the same meteorite. MAC88105 is the largest lunar meteorite yet found (662 g). MAC88104/5 is an anorthositic breccia consisting of numerous small clasts in a glassy matrix. An origin on the Moon is supported by mineral, bulk, and oxygen isotope compositions. A consortium of twenty research groups has studied these meteorites. Samples were prepared at the NASA Johnson Space Center meteorite processing laboratory. Details of consortium plans and allocations are documented herein. A summary list of lunar meteorites and an overview of consortium research is presented. Discussions in this and the following consortium papers involve the issue of paired meteorites and paired ejecta, and what new information about the nature and evolution of the lunar crust is provided by the lunar meteorites.

  14. Meteorite infall as a function of mass - Implications for the accumulation of meteorites on Antarctic ice

    NASA Technical Reports Server (NTRS)

    Huss, Gary R.

    1990-01-01

    Antarctic meteorites are considerably smaller, on average, than those recovered elsewhere in the world, and seem to represent a different portion of the mass distribution of infalling meteorites. When an infall rate appropriate to the size of Antarctic meteorites is used (1000 meteorites 10 grams or larger/sq km/1 million years), it is found that direct infall can produce the meteorite accumulations found on eight ice fields in the Allan Hills region in times ranging from a few thousand to nearly 200,000 years, with all but the Allan Hills Main and Near Western ice fields requiring less than 30,000 years. Meteorites incorporated into the ice over time are concentrated on the surface when the ice flows into a local area of rapid ablation. The calculated accumulation times, which can be considered the average age of the exposed ice, agree well with terrestrial ages for the meteorites and measured ages of exposed ice. Since vertical concentration of meteorites through removal of ice by ablation is sufficient to explain the observed meteorite accumulations, there is no need to invoke mechanisms to bring meteorites from large areas to the relatively small blue-ice patches where they are found. Once a meteorite is on a bare ice surface, freeze-thaw cycling and wind break down the meteorite and remove it from the ice. The weathering lifetime of a 100-gram meteorite on Antarctic ice is on the order of 10,000 + or - 5,000 years.

  15. Antarctic Meteorite Newsletter, volume 6, number 2

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Meteorites from the 1981 and 1982 Antarctic collection are listed showing classification, weight, degree of weathering, degree of fractionation, % Fa, and % Fs. Physical and petrigraphic characteristics are described for 23 samples from the Allan Hills, Thiel Mountains, the Pecora Escarpment, and the Elephant Moraine locations.

  16. Geochemistry and petrography of the MacAlpine Hills lunar meteorites

    NASA Technical Reports Server (NTRS)

    Lindstrom, Marilyn M.; Mckay, David S.; Wentworth, Susan J.; Martinez, Rene R.; Mittlefehldt, David W.; Wang, Ming-Sheng; Lipschutz, Michael E.

    1991-01-01

    MacAlpine Hills 88104 and 88105, anorthositic lunar meteorites recovered form the same area in Antartica, are characterized. Petrographic studies show that MAC88104/5 is a polymict breccia dominated by impact melt clasts. It is better classified as a fragmental breccia than a regolith breccia. The bulk composition is ferroan and highly aluminous (Al2O3-28 percent).

  17. Geochemistry and petrography of the MacAlpine Hills lunar meteorites

    SciTech Connect

    Lindstrom, M.M.; McKay, D.S. ); Wentworth, S.J.; Martinez, R.R.; Mittlefehldt, D.W. ); Wang, Mingsheng; Lipschutz, M.E. )

    1991-11-01

    MacAlpine Hills 88104 and 88105 are anorthositic lunar meteorites recovered from the same area in Antarctica which are demonstrated to be paired samples of the same fall. Petrographic studies of matrix and clasts show that mAC88104/5 is a polymict breccia dominated by impact melt clasts. It contains a small amount of highland impact glass and very few regolith glass spherules. It is better classified as a fragmental breccia than a regolith breccia. The bulk composition is ferroan (mg{prime} = 63) and highly aluminous (Al{sub 2}O{sub 3} = 28%). REE and other incompatible element concentrations are very low. Compositions of anorthositic, granulitic, and impact melt breccia clasts are very similar to, but distinct from, matrix composition. MAC88104/5 is very similar in composition to the other anorthositic lunar meteorites, but each of the meteorites is distinct. The anorthositic lunar meteorites, especially MAC88104/5 and Y82192/3/86032, are very similar to North Ray Crater feldspathic fragmental breccias in composition and petrography. These fragmental lunar meteorites may have been ancient, deeply buried breccias from the megaregolith. Comparisons of chemical petrographic features and exposure histories suggest that the twelve lunar meteorites were derived from two to nine, but probably four to seven, impact onto the lunar surface. Discrepancies between the proportions of lunar meteorites and results of Apollo missions may be due to unrepresentative sampling. Lunar meteorites provide valuable new information on the nature of the lunar crust.

  18. The 1984-1985 Antarctic Search for Meteorites (ANSMET) Field Program

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.

    1986-01-01

    The purpose of the 1984-1985 ANSMET (Antarctic Search for Meteorites) expedition was to recover meteorites from the Main, Near Western, Middle Western, and Far Western icefields in the Allan Hills area and to carry out a reconnaissance of other nearby blue icefields. A brief summary of the locations and maps visited are provided.

  19. Terrestrial Ages of Antarctic Meteorites- Update 1999

    NASA Technical Reports Server (NTRS)

    Nishiizumi, Kunihiko; Welten, K. C.; Caffee, Marc W.

    1999-01-01

    We are continuing our ongoing study of cosmogenic nuclides in Antarctic meteorites. In addition to the studies of exposure histories of meteorites, we study terrestrial ages and pairing of Antarctic meteorites and desert meteorites. Terrestrial ages of Antarctic meteorites provide information on meteorite accumulation mechanisms, mean weathering lifetimes, and influx rates. The determination of Cl-36(half-life=3.01 x 10(exp 5) y) terrestrial ages is one of our long-term on-going projects, however, in many instances neither Cl-36 or C-14 (5,730 y) yields an accurate terrestrial age. Using Ca-14 (1.04 x 10(exp 5) y) for terrestrial age determinations solves this problem by filling the c,ap in half-life between 14-C and Cl-36 ages. We are now applying the new Ca-41- Cl-36 terrestrial age method as well as the Cl-36-Be-10 method to Antarctic meteorites. Our measurements and C-14 terrestrial age determinations by the University of Arizona group are always complementary. We have measured Cl-36 in over 270 Antarctic meteorites since our previous compilation of terrestrial ages. Since a large number of meteorites have been recovered from many different icefields in Antarctica, we continue to survey the trends of terrestrial ages for different icefields. We have also measured detailed terrestrial ages vs. sample locations for Allan Hills, Elephant Moraine, and Lewis Cliff Icefields, where meteorites have been found with very long ages. The updated histograms of terrestrial ages of meteorites from the Allan Hills Main Icefield and Lewis Cliff Icefield are shown. These figures include C-14 ages obtained by the University of Arizona group. Pairs of meteorites are shown as one object for which the age is the average of all members of the same fall. The width of the bars represents 70,000 years, which was a typical uncertainty for Cl-36 ages. We reduced the uncertainty of terrestrial age determinations to approx. 40,000 years by using pairs of nuclides such as Ca-41-Cl-36 or Cl

  20. Extreme metamorphism in a firn core from the Allan Hills, Antarctica, as an analogue for glacial conditions

    NASA Astrophysics Data System (ADS)

    Dadic, Ruzica; Schneebeli, Martin; Bertler, Nancy; Schwikowski, Margit; Matzl, Margret

    2015-04-01

    Understanding processes in near-zero accumulation areas can help to better understand the ranges of isotopic composition in ice cores, particularly during ice ages, when accumulation rates were lower than today. Snow metamorphism is a primary driver of the transition from snow to ice and can be accompanied by altered isotopic compositions and chemical species concentration. High degree snow metamorphism, which results in major structural changes, is little-studied but has been identified in certain places in Antarctica. Here we report on a 5-m firn core collected adjacent to a blue-ice field in the Allan Hills, Antarctica. We determined the physical properties of the snow using computer tomography (microCT) and measured the isotopic composition of δD and δ18O, as well as 210Pb activity. The core shows a high degree of snow metamorphism and an exponential decrease in specific surface area (SSA), but no clear densification, with depth. The micro-CT measurements show a homogenous and stable structure throughout the entire core, with obvious erosion features in the near-surface, where high-resolution data is available. The observed firn structure is likely caused by a combination of unique depositional and post-depositional processes. The defining depositional process is the impact deposition under high winds and with a high initial density. The defining post-depositional processes are a) increased moisture transport due to forced ventilation and high winds and b) decades of temperature-gradient driven metamorphic growth in the near surface due to prolonged exposure to seasonal temperature cycling. Both post-processes are enhanced in low accumulation regions where snow stays close to surface for a long time. We observe an irregular signal in δD and δ18O that does not follow the stratigraphic sequence. The isotopic signal is likely caused by the same post-depositional processes that are responsible for the firn structure, and that are driven by local climate

  1. Terrestrial Kr-81-Kr ages of Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Freundel, M.; Schultz, L.; Reedy, R. C.

    1986-01-01

    The production rate of Ar-38 in meteorites P(38), has been determined, as a function of the sample's chemical composition, from Kr-81-Kr exposure ages of four eucrite falls. The cosmogenic Kr-78/Kr-83 ratio is used to estimate the shielding dependence of P(38). From the 'true' Ar-38 exposure ages and the apparent Kr-81-Kr exposure ages of nine Antarctic eucrite finds, terrestrial ages are calculated. They range from about 300,000 ages (Pecora Escarpment 82502) to very recent falls (Thiel Mountains 82502). Polymict eucrites from the Allan Hills (A78132, A79017, and A81009) have within the limits of error the same exposure age (15.2 x 10 to the 6th ages) and the same terrestrial age (110,000 ages). This is taken as strong evidence that these meteorites are fragments of the same fall. A similar case is the Elephant Moraine polymict eucrites A79005, A79006, and 82600 with an exposure age of 26 x 10 to the 6th ages and a terrestrial age of 180,000 ages. EETA 79004 may be different from this group because its exposure age and terrestrial age are 21 x 10 to the 6th ages and 250,000 ages, respectively. The distribution of terrestrial ages of Allan Hills meteorites is discussed. Meteorites from this blue ice field have two sources: directly deposited falls and meteorites transported to the Allen Hills inside the moving Antarctic ice sheet. During the surface residence time meteorites decompose due to weathering processes. The weathering 'half-life' is about 160,000 ages. From the different age distributions of Allan Hills and Yamato meteorites, it is concluded that meteorite concentrations of different Antarctic ice fields need different explanations.

  2. Workshop on the Issue Martian Meteorites: Where do we Stand and Where are we Going?

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The presentations in this workshop discuss the composition of Martian meteorites. Many of the talks were on a specific meteorite, i.e., Allan Hills 84001 (ALH84001). The discovery earlier of carbonates in ALH84001 lead some researchers to suggest that there was evidence of martian life. Other possible explanations for this phenomena are given. Other papers discuss methods to sterilize martian samples, the existence of water on Mars, the facilities of the Meteorite Processing Laboratory at Johnson Space Center, comparative analyses of geologic processes and the gathering of meteorites.

  3. Negative δ 18O values in Allan Hills 84001 carbonate: Possible evidence for water precipitation on mars

    NASA Astrophysics Data System (ADS)

    Holland, G.; Saxton, J. M.; Lyon, I. C.; Turner, G.

    2005-03-01

    The Martian meteorite ALH84001 contains ˜1% by weight of carbonate formed by secondary processes on the Martian surface or in the shallow subsurface. The major form of this carbonate is chemically and isotopically zoned rosettes which have been well documented elsewhere. This study concentrates upon carbonate regions ˜200 μm across which possess previously unobserved magnesium rich inner cores, interpreted here as rosette fragments, surrounded by a later stage cement containing rare Ca-rich carbonates (up to Ca 81Mg 07Fe 04Mn 07) intimately associated with feldspar. High spatial resolution ion probe analyses of Ca-rich carbonate surrounding rosette fragments have δ 18O V-SMOW values as low as -10 ‰. These values are not compatible with deposition from a global Martian atmosphere invoked to explain ALH84001 rosettes. The range of δ 18O values are also incompatible with a fluid that has equilibrated with the Martian crust at high temperature or from remobilisation of carbonate of rosette isotopic composition. At Martian atmospheric temperatures, the small CO 2(gas)-CO 2(ice) fractionation makes meteoric CO 2 an unlikely source for -10 ‰ carbonates. In contrast, closed system Rayleigh fractionation of H 2O can generate δ 18O H2O -30 ‰, as observed at high latitudes on Earth. We suggest that atmospheric transport and precipitation of H 2O in a similar fashion to that on Earth provides a source of suitably 18O depleted water for generation of carbonate with δ 18O V-SMOW = -10 ‰.

  4. Meteorites

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter

    2015-08-01

    Meteorites have long been known to offer a unique window into planetary formation processes at the time of solar system formation and into the materials that rained down on Earth at the time of the origin of life. Their material properties determine the impact hazard of Near Earth Asteroids. Some insight into how future laboratory studies of meteorites and laboratory astrophysics simulations of relevant physical processes can help address open questions in these areas and generate new astronomical observations, comes from what was learned from the recent laboratory studies of freshly fallen meteorites. The rapid recovery of Almahata Sitta (a polymict Ureilite), Sutter's Mill (a CM chondrite regolith breccia), Novato (an L6 chondrite), and Chelyabinsk (an LL5 chondrite) each were followed by the creation of a meteorite consortium, which grew to over 50 researchers in the case of Chelyabinsk. New technologies were used to probe the organic content of the meteorites as well as their magnetic signatures, isotopic abundances, trapped noble gasses, and cosmogenic radio nucleides, amongst others. This has resulted in fascinating insight into the nature of the Ureilite parent body, the likely source region of the CM chondrites in the main asteroid belt, and the collisional environment of the CM parent body. This work has encouraged follow-up in the hope of catching more unique materials. Rapid response efforts are being developed that aim to recover meteorites as pristinely as possible from falls for which the approach orbit was measured. A significant increase in the number of known approach orbits for different meteorite types will help tie meteorite types to their asteroid family source regions. Work so far suggests that future laboratory studies may recognize multiple source regions for iron-rich ordinary chondrites, for example. Hope is that these source regions will give insight into the material properties of impacting asteroids. At least some future laboratory

  5. Measurements of Cl-36 in Antarctic meteorites and Antarctic ice using a Van de Graaff accelerator

    NASA Technical Reports Server (NTRS)

    Nishiizumi, K.; Arnold, J. R.; Finkel, R. C.; Elmore, D.; Ferraro, R. D.; Gove, H. E.; Beukens, R. P.; Chang, K. H.; Kilius, L. R.

    1979-01-01

    The paper presents measurements of cosmic-ray produced (Cl-36) in Antarctic meteorites and ice using a Van de Graaff accelerator as an ultrasensitive mass spectrometer. Results from this ion counting technique are used to support a two-stage irradiation model for the Yamato-7301 and Allan Hills-76008 meteorites and to show a long terrestrial age for Allan Hills-77002. Yamato-7304 has a terrestrial age of less than 0.1 m.y., and the (Cl-36) content of the Antarctic ice sample from the Yamato mountain is consistent with levels expected in currently depositing snow implying that the age of the ice cap at this site is less than on (Cl-36) half-life.

  6. Carbon-14 in lunar soil and in meteorites

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.

    1978-01-01

    C-14 was measured in grain-size fractions of lunar soil 10084 and in samples of the Bruderheim chondrite and of several meteorites recently found in Antarctica (Allan Hills no. 5, 6, and 8). Temperature-release patterns were investigated. It was found that C-14 is released at temperatures below melting from small soil grains (less than 74 microns), but not from meteorites or from large soil grains. Below-melting C-14 contents increase with decreasing grain size in a manner similar to solar-wind-implanted rare-gas isotope contents (Eberhardt et al., 1970), whereas the C-14 released above melting temperatures is independent of grain size, suggesting that below-melting C-14 is solar-wind-implanted and above-melting C-14 is the result of cosmic ray spallations. The activity of C-14 in lunar samples is half that measured in the Bruderheim meteorite, which fell on May 4, 1970. No C-14 activity was observed in the Allan Hills chondrites; the C-14 limits suggest that these meteorites fell more than 25,000 years ago.

  7. Chemical compositional study of 35 iron meteorites and its application in taxonomy

    NASA Technical Reports Server (NTRS)

    Wang, D.; Malvin, D. J.; Wasson, J. T.

    1985-01-01

    Structural and compositional data are reported as a guide to the classification of 35 iron meteorites. The Xinjiang iron meteorite, previously classified as III AB, is reclassified as III E on the basis of its lower Ga/Ni and Ge/Ni ratios, its wider, swollen kamacite bands, and the ubiquitous presence of haxonite, (Fe,Ni)22C. The Dongling (III CD) appears not to be a new meteorite, but to be paired with the Nantan. Four Antarctic iron meteorites, IAB Allan Hills A77250, A77263, A77289, and A77290, are classified as a paired meteorite because of their similarities in structure and in concentrations of various elements. It is shown that Cu shares certain properties with Ga and Ge, which makes them excellent taxonomic parameters.

  8. Martian "microfossils" in lunar meteorites?

    PubMed

    Sears, D W; Kral, T A

    1998-07-01

    One of the five lines of evidence used by McKay et al. (1996) for relic life in the Martian meteorite Allan Hills (ALH) 84001 was the presence of objects thought to be microfossils. These ovoid and elongated forms are similar to structures found in terrestrial rocks and described as "nanobacteria" (Folk, 1993; McBride et al., 1994). Using the same procedures and apparatus as McKay et al. (1996), we have found structures on internal fracture surfaces of lunar meteorites that cannot be distinguished from the objects described on similar surfaces in ALH 84001. The lunar surface is currently a sterile environment and probably always has been. However, the lunar and Martian meteorites share a common terrestrial history, which includes many thousands of years of exposure to Antarctic weathering. Although we do not know the origin of these ovoid and elongated forms, we suggest that their presence on lunar meteorites indicates that the objects described by McKay et al. (1996) are not of Martian biological origin.

  9. Martian "microfossils" in lunar meteorites?

    PubMed

    Sears, D W; Kral, T A

    1998-07-01

    One of the five lines of evidence used by McKay et al. (1996) for relic life in the Martian meteorite Allan Hills (ALH) 84001 was the presence of objects thought to be microfossils. These ovoid and elongated forms are similar to structures found in terrestrial rocks and described as "nanobacteria" (Folk, 1993; McBride et al., 1994). Using the same procedures and apparatus as McKay et al. (1996), we have found structures on internal fracture surfaces of lunar meteorites that cannot be distinguished from the objects described on similar surfaces in ALH 84001. The lunar surface is currently a sterile environment and probably always has been. However, the lunar and Martian meteorites share a common terrestrial history, which includes many thousands of years of exposure to Antarctic weathering. Although we do not know the origin of these ovoid and elongated forms, we suggest that their presence on lunar meteorites indicates that the objects described by McKay et al. (1996) are not of Martian biological origin. PMID:11543077

  10. Martian "microfossils" in lunar meteorites?

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.; Kral, Timothy A.

    1998-07-01

    One of the five lines of evidence used by McKay et al. (1996) for relic life in the martian meteorite Allan Hills (ALH) 84001 was the presence of objects thought to be microfossils. These ovoid and elongated forms are similar to structures found in terrestrial rocks and described as "nanobacteria" (Folk, 1993; McBride et al., 1994). Using the same procedures and apparatus as McKay et al. (1996), we have found structures on internal fracture surfaces of lunar meteorites that cannot be distinguished from the objects described on similar surfaces in ALH 84001. The lunar surface is currently a sterile environment, and probably always has been. However, the lunar and martian meteorites share a common terrestrial history, including many thousands of years of exposure to Antarctic weathering. While we do not know the origin of these ovoid and elongated forms, we suggest that their presence on lunar meteorites indicates that the objects described by McKay et al. (1996) are not of martian biological origin.

  11. Antarctic Meteorite Location and Mapping Project (AMLAMP): Antarctic meteorite location map series explanatory text and user's guide to AMLAMP data

    NASA Technical Reports Server (NTRS)

    Schutt, J.; Fessler, B.; Cassidy, W. A.

    1993-01-01

    This technical report is an update to LPI Technical Report 89-02, which contained data and information that was current to May 1987. Since that time approximately 4000 new meteorites have been collected, mapped, and characterized, mainly from the numerous ice fields in the Allan Hills-David Glacier region, from the Pecora Escarpment and Moulton Escarpment in the Thiel Mountains-Patuxent region, the Wisconsin Range region, and from the Beardmore region. Meteorite location maps for ice fields from these regions have been produced and are available. This report includes explanatory texts for the maps of new areas and provides information on updates of maps of the areas covered in LPI Technical Report 89-02. Sketch maps and description of locales that have been searched and have yielded single or few meteorites are also included. The meteorite listings for all the ice fields have been updated to include any classification changes and new meteorites recovered from ice fields in the Allan Hills-David Glacier region since 1987. The text has been reorganized and minor errors in the original report have been corrected. Computing capabilities have improved immensely since the early days of this project. Current software and hardware allow easy access to data over computer networks. With various commercial software packages, the data can be used many different ways, including database creation, statistics, and mapping. The databases, explanatory texts, and the plotter files used to produce the meteorite location maps are available through a computer network. Information on how to access AMLAMP data, its formats, and ways it can be used are given in the User's Guide to AMLAMP Data section. Meteorite location maps and thematic maps may be ordered from the Lunar and Planetary Institute. Ordering information is given in Appendix A.

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

    SciTech Connect

    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 /sup 26/Al, /sup 10/Be and /sup 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 /sup 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 /sup 26/Al results of the Battelle Northwest group which indicated a disturbed profile down to 17 g/cm/sup 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 /sup 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 /sup 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.

  13. The natural thermoluminescence of meteorites. 7: Ordinary chondrites from the Elephant Moraine region, Antarctica

    NASA Technical Reports Server (NTRS)

    Benoit, P. H.; Roth, J.; Sears, H.; Sears, D. W. G.

    1994-01-01

    We report natural and induced thermoluminescence (TL) measurements for meteorites from the Elephant Moraine region (76 deg 17 min S, 157 deg 20 min E) of Antarctica. We use our data to identify fragmented meteorites (i.e., 'pairings'); our dataset of 107 samples represents at most 73 separate meteorite falls. Pairing groups are generally confined to single icefields, or to adjacent icefields, but a small proportion cross widely separated icefields in the region, suggesting that the fields can be considered as a single unit. Meteorites from this region have high natural TL levels, which indicates that they have small terrestrial surface exposure ages (less than 12,500 years). There do not appear to be significant differences in natural TL levels (and hence surface exposure ages) between individual blue icefields in the region. The proportion of reheated meteorites from the Elephant Moraine region is similar to that of other Antarctic sites and modern falls, consistent with the uniformity of the meteoritic flux in this regard. An unusual subset of H-chondrites, with high induced TL peak temperatures, is absent among the data for meteorites collected in the Elephant Moraine region, which stresses their similarity to modern falls. We suggest that the Elephant Moraine region, which stresses their similarity to modern falls. We suggest that the Elephant Moraine icefields formed through shallow ablation of the ice. Unlike the Allan Hills sites to the south, lateral transport is probably less important relative to the infall of meteorites in concentrating meteorites on these icefields.

  14. Combining meteorites and missions to explore Mars.

    PubMed

    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 (< 1.3 Ga), the spread of whole rock isotopic compositions results from crystallization of a magma ocean > 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.

  15. Combining meteorites and missions to explore Mars.

    PubMed

    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 (< 1.3 Ga), the spread of whole rock isotopic compositions results from crystallization of a magma ocean > 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. PMID:21969535

  16. Combining meteorites and missions to explore Mars

    PubMed Central

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

    2011-01-01

    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 (< 1.3 Ga), the spread of whole rock isotopic compositions results from crystallization of a magma ocean > 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. PMID:21969535

  17. The MacAlpine Hills lunar meteorite and implications of the lunar meteorites collectively for the composition and origin of the moon

    NASA Technical Reports Server (NTRS)

    Warren, Paul H.; Kallemeyn, Gregory W.

    1991-01-01

    The MAC88104/105 meteorite, a lunar highlands regolith breccia, is described. The rock and a number of its component clasts are characterized. One of the clasts is considered to be a rare pristine nonmare rock containing extraordinarily Fe-rich (Fo40) olivine; the other has silicate compositions that extend the range of the Mg-suite in the direction of the high-mg* end of the ferroan-anorthositic suite. For the major element composition of the crust, the highlands meteorites confirm that the two low-Th central nearside sites, Luna 20 and Apollo 16, are approximately representative. The high Al2O3 composition indicated for the upper crusts supports the magmasphere hypothesis. For the trace-element composition of the crust, the highlands meteorites indicate that the central nearside Apollo and Luna sites are in several respects grossly unrepresentative.

  18. Clay-mineraloid weathering products in Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Gooding, James L.

    1986-01-01

    The production of clay mineraloids (CMs) in the weathering of stony meteorites recovered in the Allan Hills and Elephant Moraine areas of Antarctica is investigated, applying electron microbeam analysis, pyrolysis/mass spectroscopy, X-ray diffractometry, and differential scanning calorimetry to whole-rock chips from two eucrites, two diogenites, and an H5 chondrite. The data are presented in tables, graphs, and photomicrographs and characterized in detail. Massive to incipient-vermicular CM formations with smectitelike or micalike compositions and indications of poor crystallization are observed and attributed to hydrocryogenic diagenesis (with little or no liquid water) on time scales of 10-1000 kyr. The need to take the compositional effects of weathering into account before attempting to reconstruct the preterrestrial histories of meteorites is stressed.

  19. The MacAlpine Hills lunar meteorite and implications of the lunar meteorites collectively for the composition and origin of the Moon

    SciTech Connect

    Warren, P.H.; Kallemeyen, G.W. )

    1991-11-01

    The MAC88104/MAC88105 meteorite is a lunar highlands regolith breccia even more anorthositic than previously available samples of highlands regolith. Clasts studied include two unusual pristine rocks. One, a 2.5-mm, slightly granulitic clast rated as probably pristine, contains extraordinarily Fe-rich (Fo{sub 40}) olivine. The other, a 5-mm clast with clear vestiges of a poikilitic cumulate texture, has silicate compositions that extend the range of the Mg-suite in the direction of the high-mg end of the ferroan-anorthositic suite. The pyroxene of the latter clast is relatively Ca-rich and poorly equilibrated by lunar cumulate standards, suggesting that it may have formed in an uncommonly shallow intrusion. The consistently high-Al{sub 2}O{sub 3} composition indicated for the upper crust supports the magmasphere hypothesis. For the trace-element composition of the crust, the highlands meteorites indicate that the central nearside Apollo and Luna sites are in several respects grossly unrepresentative. Concentrations of siderophile elements are far lower in highlands-meteoritic regolith breccias than in their central nearside counterparts. The high overall siderophile levels and hyperchondritic Ni/Ir and Au/Ir ratios characteristic of highlands materials from Apollo 16 and Apollo 14 are evidently idiosyncracies of the central nearside. Concentrations of incompatible elements, including K, Th, and U, are far lower in the highlands meteorites than in regolith samples from the central nearside. This trend implies that certain lower limits on the bulk-Moon content of U (and associated refractory lithophile elements) should be relaxed. Models of lunar origin implying large enrichments of refractory lithophile elements are not favored by the new constraints from these meteorites.

  20. Antarctic Meteorite Newsletter, Volume 28, Number 2

    NASA Technical Reports Server (NTRS)

    Righter, Kevin (Editor); Satterwhite, Cecilia (Editor)

    2005-01-01

    This newsletter contains classifications for 274 new meteorites from the 2003 and 2004 ANtarctic Search for METeorites (ANSMET) collections. They include samples from the Cumulus Hills, Larkman Nunatak, LaPaz Ice Field, MacAlpine Hills, Dominion Range, Miller Range, Roberts Massif, and Sandford Cliffs. Tables are provided of the newly classified Antarctic meteorites, meteorites classified by type, and tentative pairings petrographic descriptions.

  1. The Antarctic environment and its effect upon the total carbon and sulfur abundances in recovered meteorites

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Andrawes, F. F.

    1980-01-01

    Total carbon and sulfur abundances have been measured for 25 meteorites recovered from the Allan Hills area of Antarctica. The majority (greater than 67%) of the meteorites analyzed do not contain enriched carbon abundances resulting from weathering processes. The presence of secondary carbonates in samples which give no apparent evidence of weathering was noted during pyrolysis experiments, despite the 'normal' total carbon abundances. In selected cases, the surfaces of weathered samples may contain up to a factor of two greater carbon content than the interior. Variations in carbon abundances may reflect the degree of weathering and the amount of secondary minerals present. One of the surprises of this study is that the majority of the Antarctic meteorites studied do not exhibit total carbon and sulfur abundances outside the ranges previously observed for falls.

  2. Meteoritic event recorded in Antarctic ice

    SciTech Connect

    Harvey, R.P.; Dunbar, N.W.; McIntosh, W.C.; Esser, R.P.; Nishiizumi, Kuni; Taylor, S.; Caffee, M.W.

    1998-07-01

    During systematic sampling of volcanic ash (tephra) layers at a well-known Antarctic meteorite collection site (the Allan Hills main ice field), a band of unusually dark and rounded (many spheroidal) particles was discovered. This debris layer (BIT-58) extends parallel to the stratigraphy of the ice established from the tephra bands, apparently marking a single depositional event. The shapes, internal texture, major element composition, and levels of cosmogenic nuclides of particles from within BIT-58 all strongly suggest that this material represents ablation debris from the passage of a large H-group ordinary chondrite. Preliminary cosmogenic isotope dating suggests an age of 2.8 Ma, implying that the East Antarctic ice sheet has been stable since that time. The relationship of the Bit-58 layer to known impact events is not clear.

  3. Allan Hills 84025 - The second brachinite, far more differentiated than brachina, and an ultramafic achondritic clast from L chondrite Yamato 75097

    NASA Technical Reports Server (NTRS)

    Warren, P. H.; Kallemeyn, G. W.

    1989-01-01

    New bulk-compositional and petrographic data tend to confirm that dunitic-wehrlitic meteorite ALH84025 is a second brachinite. It is suggested here that ALH84025 originated as an olivine heteradcumulate, whereas Brachina, or ALH84025, originated as an olivine orthocumulate. The tendency for pyroxenes among brachinites to be high-Ca may be a consequence of a relatively low MgO/FeO ratio, and/or high Na/Ca and K/Ca ratios in the bulk parent body. New data for a 2.5-cm dunite-melatroctolite clast from L6 chondrite Y75097 are reported. This clast has experience depletion of middle REE, except for a large (+) Eu anomaly. The clast as a whole is enriched in phosphates, but almost exclusively in its least-metamorphosed 'core' portion, whereas the analyzed samples represent phosphate-poor portions. It is suggested that this bizarre assemblage probably originated as an achondrite containing cumulus olivine, plagioclase, and phosphate, not necessarily all from a single igneous source rock.

  4. Petrology and chemistry of hyperferroan anorthosites and other clasts from lunar meteorite ALHA81005

    SciTech Connect

    Goodrich, C.A.; Taylor, G.J.

    1984-11-15

    The results of petrographic and chemical studies of 11 previously undescribed clasts from the lunar meteorite Allan Hills A81005 are reported. The majority of lithic clasts in this regolith breccia are granular to cataclastic polymict breccias that are mixtures of ferroan anorthosites and troctolitic Mg-suite plutonic rocks with mg greater than 84, An 97, and REE abundances consistent with those of known Mg-suite rocks. Clasts of appropriate Mg-suite end members have not been found in 81005, although magnesian olivine fragments are present. Impact-melt clasts similar in composition to bulk 81005 also occur. AH81005 is low in KREEP.

  5. The Acapulco meteorite - Chemistry, mineralogy and irradiation effects

    NASA Astrophysics Data System (ADS)

    Palme, H.; Schultz, L.; Spettel, B.; Weber, H. W.; Wanke, H.; Michel-Levy, M. C.; Lorin, J. C.

    1981-05-01

    The mineralogy, chemical composition and radiation exposure history of the Acapulco meteorite, an object with a chondritic composition but achondritic texture which fell in August, 1976, are investigated. Sections of the meteorite were examined by optical and scanning electron microscopy and analyzed by electron microprobe and X-ray energy dispersive analysis; bulk samples were analyzed to yield concentrations of 50 elements, as well as light and heavy rare gas components and cosmic ray and fission track densities. A high degree of recrystallization and the mineral composition indicate meteorite formation under redox conditions intermediate between those of H and E chondrites at 1100 C, with cooling at a rate greater than 10 C/million years. The major element composition is within the range of H chondrites, however depletions in chalcophile elements and enrichments in Cr, P, U, light rare earth elements, volatile elements, planetary noble gases, and refractory siderophile are found. An old K-Ar age (4.7 billion years) and high Pu-244 track densities suggest that Acapulco may represent a rock formed in the early stages of melting of a chondritic parent body. Oxygen isotope and chemical data are then used to distinguish three groups of such reduced chondritic meteorites, comprising: (1) Acapulco, Lodran and Allan Hills A 77081; (2) Pontlyfini, Mount Morris, Winona and silicate inclusions in IAB meteorites; and (3) Kakangari.

  6. Meteorite Infall and Transport in Antarctica: An Analysis of Icefields as Accumulation Surfaces

    NASA Technical Reports Server (NTRS)

    Benoit, P. H.; Sears, D. W. G.

    1997-01-01

    Over 10,000 meteorite fragments have been collected on only a dozen or so small icefields in Antarctica. The terrestrial history of these meteorites is important, both from the perspective of the effects of their ambient environment on the meteorites themselves, and on the information that can be derived in relation to ice flow and ice stability over periods of time up to 1 million years. We discuss the relative importance of meteorite infall, and ice and aeolian transport in creating meteorite accumulations and the importance of ice and aeolian transport and weathering in removing meteorites at various icefields in Antarctica. The present analysis is confined to equibrated ordinary chondrites. We use the natural thermoluminescence (TL) to to examine the effects of weathering. Natural TL is used in combination with size analysis to gauge the effects of aeolian transport. Some icefields, especially the Lewis Cliff Ice Tongue, are dominated by wind-transported fragments, while others, including the Far Western field at Allan Hills, have lost fragments. It appears that most Antarctic icefields preserve meteorite collections on time scales of a few tens of thousands of years.

  7. A search for endogenous amino acids in martian meteorite ALH84001.

    PubMed

    Bada, J L; Glavin, D P; McDonald, G D; Becker, L

    1998-01-16

    Trace amounts of glycine, serine, and alanine were detected in the carbonate component of the martian meteorite ALH84001 by high-performance liquid chromatography. The detected amino acids were not uniformly distributed in the carbonate component and ranged in concentration from 0.1 to 7 parts per million. Although the detected alanine consists primarily of the L enantiomer, low concentrations (<0.1 parts per million) of endogenous D-alanine may be present in the ALH84001 carbonates. The amino acids present in this sample of ALH84001 appear to be terrestrial in origin and similar to those in Allan Hills ice, although the possibility cannot be ruled out that minute amounts of some amino acids such as D-alanine are preserved in the meteorite. PMID:9430583

  8. A search for endogenous amino acids in martian meteorite ALH84001

    NASA Technical Reports Server (NTRS)

    Bada, J. L.; Glavin, D. P.; McDonald, G. D.; Becker, L.

    1998-01-01

    Trace amounts of glycine, serine, and alanine were detected in the carbonate component of the martian meteorite ALH84001 by high-performance liquid chromatography. The detected amino acids were not uniformly distributed in the carbonate component and ranged in concentration from 0.1 to 7 parts per million. Although the detected alanine consists primarily of the L enantiomer, low concentrations (<0.1 parts per million) of endogenous D-alanine may be present in the ALH84001 carbonates. The amino acids present in this sample of ALH84001 appear to be terrestrial in origin and similar to those in Allan Hills ice, although the possibility cannot be ruled out that minute amounts of some amino acids such as D-alanine are preserved in the meteorite.

  9. A recent meteorite shower in Antarctica with an unusual orbital history

    NASA Technical Reports Server (NTRS)

    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. The quantum Allan variance

    NASA Astrophysics Data System (ADS)

    Chabuda, Krzysztof; Leroux, Ian D.; Demkowicz-Dobrzański, Rafał

    2016-08-01

    The instability of an atomic clock is characterized by the Allan variance, a measure widely used to describe the noise of frequency standards. We provide an explicit method to find the ultimate bound on the Allan variance of an atomic clock in the most general scenario where N atoms are prepared in an arbitrarily entangled state and arbitrary measurement and feedback are allowed, including those exploiting coherences between succeeding interrogation steps. While the method is rigorous and general, it becomes numerically challenging for large N and long averaging times.

  11. Allan Sillitoe's Lonely Hero.

    ERIC Educational Resources Information Center

    Obst, Jennifer

    1969-01-01

    The hero of Allan Sillitoe's novel, "The Loneliness of the Long-Distance Runner," differs in many ways from the typical modern existential hero. Unlike the anti-hero, Smith is not searching for values, for he understands what life is and accepts it. He follows a code of honesty and hates "phonies." He is aware of class distinctions and sees the…

  12. Mineralogic and petrologic studies of lunar samples and meteorites

    NASA Technical Reports Server (NTRS)

    Wood, J. A.

    1980-01-01

    Experimental and thermodynamic research on the pressure temperature limits of the stability of the mineral assemblages found in pristine, spinel bearing lunar highland lithologies demonstrated the likelihood that the minerals originated in the lower stratigraphic levels of the primordial crust. The phase equilibrium in silicate solid/liquid systems of planetary importance were thermochemically interpreted in order to model the early formation of the crusts and maneles of Earth and Moon sized planets. The petrography and chemical composition of coarse grained gabbro, the chemical analysis and age dating of clasts from Apollo 16 breccia, the analysis of glass particles from Apollo 16 soil samples, the study of Allende and Mokoia meteorites as a source of information about events in the solar nebula, and the hydrothermal alteration of amorphous materials were also investigated. The capabilities of a model for addressing the problem of the origin of the Earth's moon by the disruptive capture mechanism are examined as well as models of the thermal evolution of hypothetical meteorite bodies. Progress in determining the composition of stony meteorite specimens collected at the Allan Hills site during the Antarctic field exploration is reported.

  13. Radioactivities in returned lunar materials and in meteorites

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.

    1986-01-01

    A preliminary C-14 study on lunar soil was carried out with the University of Toronto Iso Trace accelerator mass spectrometer. This accelerator was recommended for C-14 work by Dr. R. Schneider of A.S. and E., who was the field engineer during the assemblage and start-up operation of the accelerator. After the preliminary study using CO2 from 10084,937 soil, which had previously been counted with low-level mini-proportional counters, it became clear that the Toronto accelerator could carry out C-14/C-13/C-12 ratio measurements on 1 gram meteorite and lunar samples and that the C-14 measurements are done with higher precision and better reliability than elsewhere. A collaborative program with the University of Toronto Iso Trace accelerator group, which is expected to be scientifically fruitful. Arrangements have been made for Dr. R.P. Beukens of the Toronto Accelerator Group to extract the carbon compounds from Antarctic meteorite and lunar samples and to convert the compounds to CO2. During the past two years, a uranium-series dating method was developed for polar ice, which method is being applied to ice from the Allan Hills site, Byrd core, and the Beardsmore glacier.

  14. Record of fluid-rock interactions on Mars from the meteorite ALH84001.

    PubMed

    Romanek, C S; Grady, M M; Wright, I P; Mittlefehldt, D W; Socki, R A; Pillinger, C T; Gibson, E K

    1994-12-15

    Allan Hills (ALH) 84001 is the most recently recognized member of a suite of meteorites--the SNCs--that almost certainly originated on Mars. Several factors distinguish ALH84001 from the other SNC meteorites. Preliminary studies suggest that it may be older than other martian meteorites. Moreover, it contains abundant, zoned domains of calcium-iron-magnesium carbonate that are indigenous to the sample and thus may hold important clues regarding near-surface processes on Mars and the evolution of the martian atmosphere. We report here analyses of the carbon and oxygen stable-isotope compositions of the carbonates that place constraints on their formation conditions. Our results imply the presence of at least two chemically distinct carbonates--one Ca,Fe-rich, the other Mg-rich--that are enriched in 13C relative to terrestrial carbonates (delta 13C approximately +41/1000), consistent with martian atmospheric CO2 as the carbon source. The oxygen isotope compositions of the carbonates indicate that they precipitated from a low-temperature fluid in the martian crust. Combined with textural and bulk geochemical considerations, the isotope data suggest that carbonate deposition took place in an open-system environment in which the ambient temperature fluctuated. PMID:7990956

  15. Petrogenesis of the SNC (shergottites, nakhlites, chassignites) meteorites - Implications for their origin from a large dynamic planet, possibly Mars

    NASA Technical Reports Server (NTRS)

    Smith, M. R.; Laul, J. C.; Ma, M. S.; Huston, T.; Verkouteren, R. M.; Lipschutz, M. E.; Schmitt, R. A.

    1984-01-01

    Comprehensive chemical data are presented on the shergottites Shergotty, Zagami, Allan Hills (ALHA) 77005, and the new member Elephant Moraine (EETA) 79001 using results of sequential instrumental and radiochemical neutron activation analysis. The close relationship of the Antarctic shergotites indicates that ALHA 77005 is a residual source produced by incongruent melting of a source similar in bulk composition to EETA 79001A and that EETA 79001B and the interstitial phases in EETA 79001A are the melts produced by such melting episodes. The large ion lithophile LIL) trace element abundanced of the shergottites require variable but extensive degrees of nomodal melting of isotopically constrained parent sources. The SNG sources are consistent with their derivation by extensive fractionation of a primitive magma initially produced from a source having chondritic refractory LIL trace element abundances. Petrogenetic and age relationships among SNC meteorites suggest a single complex-provenance on a dynamic planet not unlike earth, probably Mars.

  16. Edgar Allan Poe and neurology.

    PubMed

    Teive, Hélio Afonso Ghizoni; Paola, Luciano de; Munhoz, Renato Puppi

    2014-06-01

    Edgar Allan Poe was one of the most celebrated writers of all time. He published several masterpieces, some of which include references to neurological diseases. Poe suffered from recurrent depression, suggesting a bipolar disorder, as well as alcohol and drug abuse, which in fact led to his death from complications related to alcoholism. Various hypotheses were put forward, including Wernicke's encephalopathy.

  17. Allan Bloom, America, and Education.

    ERIC Educational Resources Information Center

    West, Thomas

    2000-01-01

    Refutes the claims of Allan Bloom that the source of the problem with today's universities is modern philosophy, that the writings and ideas of Hobbes and Locke planted the seeds of relativism in American culture, and that the cure is Great Books education. Suggests instead that America's founding principles are the only solution to the failure of…

  18. Polycyclic aromatic hydrocarbons (PAHs) in Antarctic Martian meteorites, carbonaceous chondrites, and polar ice.

    PubMed

    Becker, L; Glavin, D P; Bada, J L

    1997-01-01

    Recent analyses of the carbonate globules present in the Martian meteorite ALH84001 have detected polycyclic aromatic hydrocarbons (PAHs) at the ppm level (McKay et al., 1996). The distribution of PAHs observed in ALH84001 was interpreted as being inconsistent with a terrestrial origin and were claimed to be indigenous to the meteorite, perhaps derived from an ancient martian biota. We have examined PAHs in the Antarctic shergottite EETA79001, which is also considered to be from Mars, as well as several Antarctic carbonaceous chondrites. We have found that many of the same PAHs detected in the ALH84001 carbonate globules are present in Antarctic carbonaceous chondrites and in both the matrix and carbonate (druse) component of EETA79001. We also investigated PAHs in polar ice and found that carbonate is an effective scavenger of PAHs in ice meltwater. Moreover, the distribution of PAHs in the carbonate extract of Antarctic Allan Hills ice is remarkably similar to that found in both EETA79001 and ALH84001. The reported presence of L-amino acids of apparent terrestrial origin in the EETA79001 druse material (McDonald and Bada, 1995) suggests that this meteorite is contaminated with terrestrial organics probably derived from Antarctic ice meltwater that had percolated through the meteorite. Our data suggests that the PAHs observed in both ALH84001 and EETA79001 are derived from either the exogenous delivery of organics to Mars or extraterrestrial and terrestrial PAHs present in the ice meltwater or, more likely, from a mixture of these sources. It would appear that PAHs are not useful biomarkers in the search for extinct or extant life on Mars. PMID:11541466

  19. Polycyclic aromatic hydrocarbons (PAHs) in Antarctic Martian meteorites, carbonaceous chondrites, and polar ice.

    PubMed

    Becker, L; Glavin, D P; Bada, J L

    1997-01-01

    Recent analyses of the carbonate globules present in the Martian meteorite ALH84001 have detected polycyclic aromatic hydrocarbons (PAHs) at the ppm level (McKay et al., 1996). The distribution of PAHs observed in ALH84001 was interpreted as being inconsistent with a terrestrial origin and were claimed to be indigenous to the meteorite, perhaps derived from an ancient martian biota. We have examined PAHs in the Antarctic shergottite EETA79001, which is also considered to be from Mars, as well as several Antarctic carbonaceous chondrites. We have found that many of the same PAHs detected in the ALH84001 carbonate globules are present in Antarctic carbonaceous chondrites and in both the matrix and carbonate (druse) component of EETA79001. We also investigated PAHs in polar ice and found that carbonate is an effective scavenger of PAHs in ice meltwater. Moreover, the distribution of PAHs in the carbonate extract of Antarctic Allan Hills ice is remarkably similar to that found in both EETA79001 and ALH84001. The reported presence of L-amino acids of apparent terrestrial origin in the EETA79001 druse material (McDonald and Bada, 1995) suggests that this meteorite is contaminated with terrestrial organics probably derived from Antarctic ice meltwater that had percolated through the meteorite. Our data suggests that the PAHs observed in both ALH84001 and EETA79001 are derived from either the exogenous delivery of organics to Mars or extraterrestrial and terrestrial PAHs present in the ice meltwater or, more likely, from a mixture of these sources. It would appear that PAHs are not useful biomarkers in the search for extinct or extant life on Mars.

  20. Polycyclic aromatic hydrocarbons (PAHs) in Antarctic Martian meteorites, carbonaceous chondrites, and polar ice

    SciTech Connect

    Becker, L. |; Glavin, D.P.; Bada, J.L.

    1997-01-01

    Recent analyses of the carbonate globules present in the Martian meteorite ALH84001 have detected polycyclic aromatic hydrocarbons (PAHs) at the ppm level. The distribution of PAHs observed in ALH84001 was interpreted as being inconsistent with a terrestrial origin and were claimed to be indigenous to the meteorite, perhaps derived from an ancient martian biota. We have examined PAHs in the Antarctic shergottite EETA79001, which is also considered to be from Mars, as well as several Antarctic carbonaceous chondrites. We have found that many of the same PAHs detected in the ALH84001 carbonate globules are present in Antarctic carbonaceous chondrites and in both the matrix and carbonate (druse) component of EETA79001. We also investigated PAHs in polar ice and found that carbonate is an effective scavenger of PAHs in ice meltwater. Moreover, the distribution of PAHs in the carbonate extract of Antarctic Allan Hills ice is remarkably similar to that found in both EETA79001 and ALH84001. The reported presence of L-amino acids of apparent terrestrial origin in the EETA79001 druse material suggests that this meteorite is contaminated with terrestrial organics probably derived from Antarctic ice meltwater that had percolated through the meteorite. Our data suggests that the PAHs observed in both ALH84001 and EETA79001 are derived from either the exogenous delivery of organics to Mars or extraterrestrial and terrestrial PAHs present in the ice meltwater or, more likely, from a mixture of these sources. It would appear that PAHs are not useful biomarkers in the search for extinct or extant life on Mars. 33 refs., 3 figs., 1 tab.

  1. A possible high-temperature origin for the carbonates in the martian meteorite ALH84001.

    PubMed

    Harvey, R P; McSween, H Y

    1996-07-01

    The meteorite Allan Hills (ALH) 84001, commonly accepted to be of martian origin, is unique among known martian meteorites in containing abundant, zoned, pre-terrestrial carbonate minerals. Previous studies of the oxygen isotope compositions of these minerals have suggested that they precipitated from a low-temperature (0-80 degrees C) aqueous fluid in the martian crust--perhaps in a near-surface hydrothermal system. Here we report analyses of the major-element compositions of the carbonates, which provide an independent constraint on the composition and temperature of the fluid from which they formed. We argue that the most likely explanation for the observed compositions, and for the absence of co-existing hydrons minerals, is that the carbonates were formed by reactions between hot (> 650 degrees C), CO2-rich fluids and the ultramatic host rock during an impact event. Impact processes on the martian surface can produce both the hot, CO2-rich fluid (by volatilization of surface carbonates or other CO2 sources) and--by brecciation--the condults through which it flowed. Impact metasomatism is also consistent with the observed oxygen isotope disequillbrium, sequence of mineral formation, and carbonate mineral zoning, reflecting carbonate formation during rapid cooling from high temperatures rather than prolonged exposure to low-temperature fluids. PMID:8657303

  2. A possible high-temperature origin for the carbonates in the martian meteorite ALH84001.

    PubMed

    Harvey, R P; McSween, H Y

    1996-07-01

    The meteorite Allan Hills (ALH) 84001, commonly accepted to be of martian origin, is unique among known martian meteorites in containing abundant, zoned, pre-terrestrial carbonate minerals. Previous studies of the oxygen isotope compositions of these minerals have suggested that they precipitated from a low-temperature (0-80 degrees C) aqueous fluid in the martian crust--perhaps in a near-surface hydrothermal system. Here we report analyses of the major-element compositions of the carbonates, which provide an independent constraint on the composition and temperature of the fluid from which they formed. We argue that the most likely explanation for the observed compositions, and for the absence of co-existing hydrons minerals, is that the carbonates were formed by reactions between hot (> 650 degrees C), CO2-rich fluids and the ultramatic host rock during an impact event. Impact processes on the martian surface can produce both the hot, CO2-rich fluid (by volatilization of surface carbonates or other CO2 sources) and--by brecciation--the condults through which it flowed. Impact metasomatism is also consistent with the observed oxygen isotope disequillbrium, sequence of mineral formation, and carbonate mineral zoning, reflecting carbonate formation during rapid cooling from high temperatures rather than prolonged exposure to low-temperature fluids.

  3. A Younger Age for the Oldest Martian Meteorite

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2010-05-01

    The Allan Hills (ALH) 84001 Martian meteorite is famous for containing fiercely-disputed evidence for fossil life. Equally important to many cosmochemists, the meteorite also contains important information about the construction of the Martian crust by magmas derived from the interior, and the subsequent modification of those igneous rocks by large impacts and circulating water. A surprising feature of ALH 84001 has been its extremely ancient age, 4.50 billion years, as determined by samarium-neodymium (Sm-Nd) and rubidium-strontium (Rb-Sr) isotopic dating. If correct, the ancient age implies that the magma in which ALH 84001 formed intruded the primordial crust, perhaps forming in a deep ocean of magma that surrounded Mars during its initial differentiation into metallic core, rocky mantle, and primary crust. New age determinations by Thomas Lapen (University of Houston) and colleagues there and at the Johnson Space Center, the Lunar and Planetary Institute, the University of Wisconsin, and the University of Brussels, Belgium, indicate that the rock crystallized in a magma 4.091 billion years ago. They used lutetium-hafnium (Lu-Hf) isotopes in determining the new age. This isotopic system has the advantage of not being affected as readily by impact heating and water alteration as are Sm-Nd and Rb-Sr. The new age is consistent with igneous activity throughout Martian history and with a period of heavy bombardment between 4.2 and 4.1 billion years as inferred from the ages of large impact basins on Mars.

  4. Antarctic Meteorite Newsletter, Volume 29, Number 1

    NASA Technical Reports Server (NTRS)

    Satterwhite, Cecilia (Editor); Righter, Kevin (Editor)

    2006-01-01

    This newsletter contains classifications for 597 new meteorites from the 2003 and 2004 ANtarctic Search for METeorites (ANSMET) seasons. They include samples from the Cumulus Hills, Dominion Range, Grosvenor Mountains, LaPaz Icefield, MacAlpine Hills, and the Miller Range. Macroscopic and petrographic descriptions are given for 25 of the new meteorites: 1 acapulcoite/Iodranite, 1 howardite, 1 diogenite, 2 eucrites, 1 enstatite chondrite, four L3 and two H3 chondrites, 2 CM, 3 CK and 1 CV chondrites, three R chondrites, and four impact melt breccias (with affinities for H and L). Likely the most interesting sample announced in this newsletter is LAP04840, with affinity to R chondrites. This meteorite contains approximately 15% horneblende, and has mineral compositional ranges and oxygen isotopic values similar to those of R chondrites. The presence of an apparently hydrous phase in this petrologic grade 6 chondrite is very unusual, and should be of great interest to many meteoriticists.

  5. Edgar Allan Poe's Physical Cosmology

    NASA Astrophysics Data System (ADS)

    Cappi, Alberto

    1994-06-01

    In this paper I describe the scientific content of Eureka, the prose poem written by Edgar Allan Poe in 1848. In that work, starting from metaphysical assumptions, Poe claims that the Universe is finite in an infinite Space, and that it was originated from a primordial Particle, whose fragmentation under the action of a repulsive force caused a diffusion of atoms in space. I will show that his subsequently collapsing universe represents a scientifically acceptable Newtonian model. In the framework of his evolving universe, Poe makes use of contemporary astronomical knowledge, deriving modern concepts such as a primordial atomic state of the universe and a common epoch of galaxy formation. Harrison found in Eureka the first, qualitative solution of the Olbers' paradox; I show that Poe also applies in a modern way the anthropic principle, trying to explain why the Universe is so large.

  6. The natural thermoluminescence of meteorites. III - Lunar and basaltic meteorites

    NASA Technical Reports Server (NTRS)

    Sears, Derek W. G.; Benoit, Paul H.; Sears, Hazel; Batchelor, J. D.; Symes, Steve

    1991-01-01

    Natural thermoluminescence (TL) data were obtained to investigate recent thermal and radiation histories of the lunar meteorite MacAlpine Hills 88104/5 and 65 eucrites, howardites, diogenites, and mesosiderites. All these meteorites have low levels of natural TL compared to chondrites, which is primarily because they display anomalous fading. Some meteorites have especially low natural TL which must reflect heating within the last 100,000-1,000,000 y. The parameters for TL decay were determined assuming plausible values for cosmic ray dose rate and that the natural TL of MAC88104/5 was totally drained by ejection from the moon. The obtained parameters for TL decay suggest that the moon-earth transit times for MAC88104 and MAC88105 were 2,000 and 1,800 y, respectively, compared with 19,000 and 2,500 y for Y791197 and ALHA81005, respectively.

  7. Iron Meteorite

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    A meteorite composed mainly of nickel-iron, with traces of other metals; also referred to simply as an iron, and formerly known as a siderite. Irons account for over 6% of all known meteorite specimens. They are the easiest type to identify, being heavy, magnetic and rust-colored; their metallic sheen tarnishes quickly on the Earth's surface, but otherwise irons show better resistance to weatheri...

  8. Meteorite craters

    NASA Technical Reports Server (NTRS)

    Ivanov, B. A.; Bazilevskiy, A. T.

    1986-01-01

    The origin and formation of various types of craters, both on the Earth and on other planetary bodies, are discussed. Various models are utilized to depict various potential causes of the types and forms of meteorite craters in our solar system, and the geological structures are also discussed.

  9. John A. Scigliano Interviews Allan B. Ellis.

    ERIC Educational Resources Information Center

    Scigliano, John A.

    2000-01-01

    This interview with Allan Ellis focuses on a history of computer applications in education. Highlights include work at the Harvard Graduate School of Education; the New England Education Data System; and efforts to create a computer-based distance learning and development program called ISVD (Information System for Vocational Decisions). (LRW)

  10. The Curious Mind of Allan Bloom.

    ERIC Educational Resources Information Center

    Gardner, Martin

    1988-01-01

    This article reviews Allan Bloom's 1987 book, THE CLOSING OF THE AMERICAN MIND: HOW HIGHER EDUCATION HAS FAILED DEMOCRACY AND IMPOVERISHED THE SOULS OF TODAY'S CHILDREN. Compares Bloom's book with THE HIGHER LEARNING IN AMERICA, a 1930s book by Mortimer Adler and Robert Hutchins. (JDH)

  11. Survey on Cosmogenic 26Al in Lewis Cliff Meteorites

    NASA Astrophysics Data System (ADS)

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

    1992-07-01

    INTRODUCTION: We have embarked upon a ^26Al gamma-ray survey of meteorites selected from about 2000 samples recently recovered from the Lewis Cliff Ice Fields (84 degrees 18'S/161 degrees 20'E). Due to its 705-ka half-life ^26Al can be used for estimating terrestrial ages and thus contribute to further characterization of Antarctic meteorites in addition to their classification and thermoluminescence (TL) properties. The ^26Al survey is also useful for identifying meteorites with unusual exposure histories, which merit additional measurements of cosmogenic radionuclides (by AMS) and noble gases. In addition, it provides clues on possible pairings. METHOD: Low-level gamma-ray spectroscopy is well suited for ^26Al survey work, since bulk meteorite samples can be measured routinely and nondestructively without any previous sample preparation. The required size of the samples (30-500 g) makes the method relatively independent of depth effects and compositional inhomogeneities. The use of a high-resolution GeLi detector also allows the determination of the natural ^40K activity and thus the K content of the samples, which can be used as an additional pairing criterion for ordinary chondrites. Also ^137Cs, a fall-out surface contamination [1], is simultaneously measured; low values may be characteristic for meteorites recently fallen or released from the ablating ice. For the detector an efficiency calibration curve has been made that adequately accounts for differences in size and shape of the meteorite samples. RESULTS and DISCUSSION: TERRESTRIAL AGES: So far, we have measured over 30 Lewis Cliff equilibrated H and L chondrites, collected from widely differing locations. Normalized to L-chondrite composition, the ^26Al contents range from 27 to 110 dpm/kg with peaks around 43 and 53 dpm/kg. This bimodal ^26Al distribution is reminiscent of that observed for Allan Hills ordinary chondrites [2]. Tentative terrestrial ages, calculated on the basis of ^26Al saturation

  12. International Workshop on Antarctic Meteorites

    NASA Technical Reports Server (NTRS)

    Annexstad, J. O.; Schultz, L.; Waenke, H.

    1986-01-01

    Topics addressed include: meteorite concentration mechanisms; meteorites and the Antarctic ice sheet; iron meteorites; iodine overabundance in meteorites; entrainment, transport, and concentration of meteorites in polar ice sheets; weathering of stony meteorites; cosmic ray records; radiocarbon dating; element distribution and noble gas isotopic abundances in lunar meteorites; thermoanalytical characterization; trace elements; thermoluminescence; parent sources; and meteorite ablation and fusion spherules in Antarctic ice.

  13. The chlorine isotopic composition of Martian meteorites 1: Chlorine isotope composition of Martian mantle and crustal reservoirs and their interactions

    NASA Astrophysics Data System (ADS)

    Williams, J. T.; Shearer, C. K.; Sharp, Z. D.; Burger, P. V.; McCubbin, F. M.; Santos, A. R.; Agee, C. B.; McKeegan, K. D.

    2016-05-01

    The Martian meteorites record a wide diversity of environments, processes, and ages. Much work has been done to decipher potential mantle sources for Martian magmas and their interactions with crustal and surface environments. Chlorine isotopes provide a unique opportunity to assess interactions between Martian mantle-derived magmas and the crust. We have measured the Cl-isotopic composition of 17 samples that span the range of known ages, Martian environments, and mantle reservoirs. The 37Cl of the Martian mantle, as represented by the olivine-phyric shergottites, NWA 2737 (chassignite), and Shergotty (basaltic shergottite), has a low value of approximately -3.8‰. This value is lower than that of all other planetary bodies measured thus far. The Martian crust, as represented by regolith breccia NWA 7034, is variably enriched in the heavy isotope of Cl. This enrichment is reflective of preferential loss of 35Cl to space. Most basaltic shergottites (less Shergotty), nakhlites, Chassigny, and Allan Hills 84001 lie on a continuum between the Martian mantle and crust. This intermediate range is explained by mechanical mixing through impact, fluid interaction, and assimilation-fractional crystallization.

  14. Polycyclic Aromatic Hydrocarbons in the Martian (SNC) Meteorite ALH 84001: Hydrocarbons from Mars, Terrestrial Contaminants, or Both?

    NASA Astrophysics Data System (ADS)

    Thomas, K. L.; Clemett, S. J.; Romanek, C. S.; Macheling, C. R.; Gibson, E. K.; McKay, D. S.; Score, R.; Zare, R. N.

    1995-09-01

    Previous work has shown that pre-terrestrial polycyclic aromatic hydrocarbons (PAHs) exist in interplanetary dust particles (IDPs) and certain meteorites [1-3]. We previously reported the first observation of PAHs in the newest member of the SNC group, Allan Hills 84001 [4] and determined that particular types of organic compounds are indigenous to ALH 84001 because they are associated with certain mineralogical features [4]. We also analyzed two diogenites from Antarctica: one showed no evidence for aromatic hydrocarbons while the other contained PAHs with the same major peaks as those in ALH 84001[4]. PAHs in the diogenite meteorite are not associated with mineral features on the analyzed surface and the most abundant PAHs in the diogenite are lower by a factor of 3 than those in ALH 84001. Furthermore, ALH 84001 contains a number of minor PAHs not found in the diogenite or typical terrestrial soils [4]. In this study we are analyzing a more complete group of Antarctic and non-Antarctic meteorites, including SNCs, to determine: (1) PAHs abundance and diversity in Antarctic meteorites and (2) the contribution of PAHs in SNCs from martian and, possibly, terrestrial sources. ALH 84001 is an unusual orthopyroxenite which contains abundant carbonate spheroids which are ~100-200 micrometers in diameter and range in composition from magnesite to ferroan magnesite [5-7]. These spheroids are not the result of terrestrial contamination: oxygen isotopic compositions indicate that the carbonates probably precipitated from a low-temperature fluid within the martian crust [5] and carbon isotopic abundances are consistent with martian atmospheric CO2 as the carbon source [5]. PAHs may coexist with other low-temperature carbon-bearing phases in a subsurface martian environment. Samples: We are analyzing freshly-fractured meteorite samples, or chips, which have been extracted from the internal regions of the following meteorites: ALH 84001 (crush and uncrush zones), EETA79001

  15. The Cosmology of Edgar Allan Poe

    NASA Astrophysics Data System (ADS)

    Cappi, Alberto

    2011-06-01

    Eureka is a ``prose poem'' published in 1848, where Edgar Allan Poe presents his original cosmology. While starting from metaphysical assumptions, Poe develops an evolving Newtonian model of the Universe which has many and non casual analogies with modern cosmology. Poe was well informed about astronomical and physical discoveries, and he was influenced by both contemporary science and ancient ideas. For these reasons, Eureka is a unique synthesis of metaphysics, art and science.

  16. [The medical history of Edgar Allan Poe].

    PubMed

    Miranda C, Marcelo

    2007-09-01

    Edgar Allan Poe, one of the best American storytellers and poets, suffered an episodic behaviour disorder partially triggered by alcohol and opiate use. Much confusion still exists about the last days of his turbulent life and the cause of his death at an early age. Different etiologies have been proposed to explain his main medical problem, however, complex partial seizures triggered by alcohol, poorly recognized at the time when Poe lived, seems to be one of the most acceptable hypothesis, among others discussed.

  17. Survey on Cosmogenic 26Al in Lewis Cliff Meteorites

    NASA Astrophysics Data System (ADS)

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

    1992-07-01

    INTRODUCTION: We have embarked upon a ^26Al gamma-ray survey of meteorites selected from about 2000 samples recently recovered from the Lewis Cliff Ice Fields (84 degrees 18'S/161 degrees 20'E). Due to its 705-ka half-life ^26Al can be used for estimating terrestrial ages and thus contribute to further characterization of Antarctic meteorites in addition to their classification and thermoluminescence (TL) properties. The ^26Al survey is also useful for identifying meteorites with unusual exposure histories, which merit additional measurements of cosmogenic radionuclides (by AMS) and noble gases. In addition, it provides clues on possible pairings. METHOD: Low-level gamma-ray spectroscopy is well suited for ^26Al survey work, since bulk meteorite samples can be measured routinely and nondestructively without any previous sample preparation. The required size of the samples (30-500 g) makes the method relatively independent of depth effects and compositional inhomogeneities. The use of a high-resolution GeLi detector also allows the determination of the natural ^40K activity and thus the K content of the samples, which can be used as an additional pairing criterion for ordinary chondrites. Also ^137Cs, a fall-out surface contamination [1], is simultaneously measured; low values may be characteristic for meteorites recently fallen or released from the ablating ice. For the detector an efficiency calibration curve has been made that adequately accounts for differences in size and shape of the meteorite samples. RESULTS and DISCUSSION: TERRESTRIAL AGES: So far, we have measured over 30 Lewis Cliff equilibrated H and L chondrites, collected from widely differing locations. Normalized to L-chondrite composition, the ^26Al contents range from 27 to 110 dpm/kg with peaks around 43 and 53 dpm/kg. This bimodal ^26Al distribution is reminiscent of that observed for Allan Hills ordinary chondrites [2]. Tentative terrestrial ages, calculated on the basis of ^26Al saturation

  18. Formation of Carbonate Minerals in Martian Meteorite ALH 84001 from Cool Water Near the Surface of Mars

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2011-12-01

    Carbonate minerals in the Allan Hills 84001 meteorite are important because they ought to contain information about the chemistry and temperature of the water they formed in. They are also an important part of testing the idea that the meteorite contains evidence of past life on Mars. Hypotheses for the origin of the carbonates are impressively varied. A key test of the ideas is to determine the temperature at which the carbonates formed. Estimates up to now range from a bit below freezing to 700 oC, too big a range to test anything! To address the problem Itay Halevy, Woodward Fischer, and John Eiler (Caltech) used an approach that involves "clumped" isotope thermometry, which makes comparisons among different isotopic compositions of extracted CO2. This allowed the investigators to use the isotopic abundances of both carbon and oxygen. The results indicate that the carbonates formed at 18 ± 4 oC from a shallow subsurface (upper few meters to tens of meters) pool of water that was gradually evaporating. The wet episode did not last long, leading Halevy and his colleagues to conclude that the environment may have been too transient for life to have emerged here from scratch. On the other hand, if life already existed on the Martian surface this wet near-surface environment would have provided a happy home. An impact blasted the Martian home of ALH 84001, causing a transient heating event, perhaps disturbing the isotopic record...or perhaps not because the event was so short. In any case, the clumped isotope thermometry approach seems to have given a good measurement of the temperature at which the carbonate minerals formed.

  19. Antarctic Meteorite Newsletter, Volume 31, No. 1

    NASA Technical Reports Server (NTRS)

    Satterwhite, Cecilia (Editor); Righter, Kevin (Editor)

    2008-01-01

    This newsletter reports 418 new meteorites from the 2004 and 2006 ANSMET seasons from the Cumulus Hills (CMS), LaPaz Ice Field (LAP), Graves Nunataks (GRA), Grosvenor Mountains (GRO), Larkman Nunatak (LAR), MacAlpine Hills (MAC), Miller Range (MIL), Roberts Massif (RBT), and Scott Glacier (SCO). These new samples include one iron, 1 eucrite, 1 mesosiderite, 6 CK chondrites (2 with pairing), 2 CV3 chondrites, 1 CM1, 7 CM2 (4 with pairing), 3 CR2 (2 with pairing), and one each of a type 3 L and H chondrites. The CK6 chondrites (LAR 06869, 06872, 06873) are unusual in that they have no discernable chondrules, extremely fine-grained texture, and are full of veins. This newsletter represents a break from recent newsletters in which we have announced many unusual and popular samples, including new lunar and martian meteorites, an unusual achondrite (GRA 06128 and 06129 the topic of a special session at this years LPSC).

  20. Black Hills

    Atmospheric Science Data Center

    2014-05-15

    article title:  Drought in the Black Hills     View ... and western South Dakota remain in the midst of a severe drought. This set of images and maps from NASA's Multi-angle Imaging ... the 2000 and 2004 dates. As the vegetation faded with the drought, the  albedo  at the surface increased. Albedo measures the ...

  1. The natural thermoluminescence of meteorites: III. Lunar and basaltic meteorites

    SciTech Connect

    Sears, D.W.G.; Benoit, P.H.; Sears, H.; Batchelor, J.D.; Symes, S. )

    1991-11-01

    Natural thermoluminescence (TL) data have been obtained for the lunar meteorite MacAlpine Hills 88104/5 and for 65 eucrites, howardites, diogenites, and mesosiderites in order to investigate their recent thermal and radiation histories. All these meteorites have low levels of natural TL compared to chondrites, which is primarily because they display anomalous fading (i.e., fading by non-classical mechanisms). However, some have especially low natural TL (<5 krad at 250C in the glow curve) which cannot be attributed to anomalous fading or thermal fading over especially large terrestrial ages, and which must reflect heating within the last 10{sup 5}-10{sup 6} y. The fraction of basaltic meteorites thought to have had small perihelia (about 20%) is comparable to the fraction of chondrites with low natural TL and to the fraction of observed falls and fireballs with small perihelia. This may imply ejection from the asteroid belt via similar mechanisms. Assuming plausible values for cosmic ray dose rate, and that the natural TL of MAC88104/5 was totally drained by ejection form the moon, the parameters for TL decay determined in the present study suggest that the Moon-Earth transit times for MAC88104 and MAC88105, were 2,00 and 1.800 y, respectively, compared with 19,000 and 2,500 y for Y791197 and ALHA81005 were ejected from the moon by the same event should be considered, since diverse rock types are found in close proximity on the lunar surface. The natural TL data confirm most previous published pairings among basaltic meteorites and suggest others.

  2. Rediscovery of Polish meteorites

    NASA Astrophysics Data System (ADS)

    Tymiński, Z.; Stolarz, M.; Żołądek, P.; Wiśniewski, M.; Olech, A.

    2016-01-01

    The total number of Polish registered meteorites (by July 2016) including the meteoritical artifacts as Czestochowa Raków I and II is 22. Most of them are described by the pioneer of Polish Meteoritics Jerzy Pokrzywnicki who also identified the meteorite fall locations. In recent years prospectors found impressive specimens of known Polish meteorites such as Morasko: 34 kg, 50 kg, 164 kg, 174 kg and 261 kg or Pultusk: 1578 g, 1576 g, 1510 g, 610 g and 580 g expanding and determining precisely the known meteorite strewn fields.

  3. Meteorite Falls in Morocco

    NASA Astrophysics Data System (ADS)

    Chennaoui Aoudjehane, H.

    2016-08-01

    The number of meteorite falls reported in Morocco since 2000 is highest than any other place compared to the other countries in the world, that call into question the efficiency of the randomly meteorite falls on Earth.

  4. Searching for Meteorites

    NASA Video Gallery

    This lesson combines a series of activities to provide students with an understanding of how meteorites can unlock answers to the early history of the solar system and how meteorites and their big ...

  5. Obituary: Allan R. Sandage (1926-2010)

    NASA Astrophysics Data System (ADS)

    Devorkin, David

    2011-12-01

    Allan Rex Sandage died of pancreatic cancer at his home in San Gabriel, California, in the shadow of Mount Wilson, on November 13, 2010. Born in Iowa City, Iowa, on June 18, 1926, he was 84 years old at his death, leaving his wife, former astronomer Mary Connelly Sandage, and two sons, David and John. He also left a legacy to the world of astronomical knowledge that has long been universally admired and appreciated, making his name synonymous with late 20th-Century observational cosmology. The only child of Charles Harold Sandage, a professor of advertising who helped establish that academic specialty after obtaining a PhD in business administration, and Dorothy Briggs Sandage, whose father was president of Graceland College in Iowa, Allan Sandage grew up in a thoroughly intellectual, university oriented atmosphere but also a peripatetic one taking him to Philadelphia and later to Illinois as his father rose in his career. During his 2 years in Philadelphia, at about age eleven, Allan developed a curiosity about astronomy stimulated by a friend's interest. His father bought him a telescope and he used it to systematically record sunspots, and later attempted to make a larger 6-inch reflector, a project left uncompleted. As a teenager Allan read widely, especially astronomy books of all kinds, recalling in particular The Glass Giant of Palomar as well as popular works by Eddington and Hubble (The Realm of the Nebulae) in the early 1940s. Although his family was Mormon, of the Reorganized Church, he was not practicing, though he later sporadically attended a Methodist church in Oxford, Iowa during his college years. Sandage knew by his high school years that he would engage in some form of intellectual life related to astronomy. He particularly recalls an influential science teacher at Miami University in Oxford, Ohio named Ray Edwards, who inspired him to think critically and "not settle for any hand-waving of any kind." [Interview of Allan Rex Sandage by Spencer

  6. Three-dimensional Allan fault plane analysis

    SciTech Connect

    Hoffman, K.S.; Taylor, D.R.; Schnell, R.T.

    1994-12-31

    Allan fault-plane analysis is a useful tool for determining hydrocarbon migration paths and the location of possible traps. While initially developed for Gulf coast deltaic and interdeltaic environments, fault-plane analysis has been successfully applied in many other geologic settings. Where the geology involves several intersecting faults and greater complexity, many two-dimensional displays are required in the investigation and it becomes increasingly difficult to accurately visualize both fault relationships and migration routes. Three-dimensional geospatial fault and structure modeling using computer techniques, however, facilitates both visualization and understanding and extends fault-plane analysis into much more complex situations. When a model is viewed in three dimensions, the strata on both sides of a fault can be seen simultaneously while the true structural character of one or more fault surfaces is preserved. Three-dimensional analysis improves the speed and accuracy of the fault plane methodology.

  7. Petrography of Lunar Meteorite MET 01210, A New Basaltic Regolith Breccia

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    Lunar meteorite MET 01210 (hereafter referred to as MET) is a 22.8 g breccia collected during the 2001 field season in the Meteorite Hills, Antarctica. Although initially classified as an anorthositic breccia, MET is a regolith breccia composed predominantly of very-low-Ti (VLT) basaltic material. Four other brecciated lunar meteorites (NWA 773, QUE 94281, EET 87/96, Yamato 79/98) with a significant VLT basaltic component have been identified. We present here the petrography and bulk major element composition of MET and compare it to previously studied basaltic lunar meteorite breccias.

  8. 32. SCIENTISTS ALLAN COX (SEATED), RICHARD DOELL, AND BRENT DALRYMPLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. SCIENTISTS ALLAN COX (SEATED), RICHARD DOELL, AND BRENT DALRYMPLE AT CONTROL PANEL, ABOUT 1965. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

  9. Squeezing Meteorites to Reveal the Martian Mantle

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2006-12-01

    A piece of a Martian lava flow, Antarctic meteorite Yamato-980459, appears to represent the composition of a magma produced by partial melting of the Martian interior. That's the view of researchers Don Musselwhite, Walter Kiefer, and Allan Treiman (Lunar and Planetary Institute, Houston) and Heather Dalton (Arizona State University). Musselwhite and his colleagues determined that this basaltic Martian meteorite represented a primary melt from the mantle. This was an important discovery because magma produced inside a planet contains significant clues to the composition of the region of the interior in which it formed. The lava flows that decorate the surface of planets tell us about the mantle, the rocky region beneath the crust and above the metallic core. The researchers used apparatus at the Johnson Space Center to determine what minerals are present when samples with the composition of Y-980459 are heated to a range of temperatures and squeezed to a range of pressures like those that planetary scientists expect to exist in the interior of Mars. The results indicate that the magma represented by this special meteorite formed at a depth of about 100 kilometers and a temperature of about 1540 degrees C. From the high temperature and high ratio of magnesium to iron in the magma, Musselwhite and his colleagues infer that the amount of melting to produce the Y-980459 parent magma was high, which suggests that the temperature at the boundary between the metallic core and the rocky mantle was higher than previous estimates. This work gives us clues to the composition and dynamics of the Martian interior--all from a rock chipped off a lava flow on Mars and flung to Earth by an impact.

  10. Antarctic Meteorite Newsletter

    NASA Technical Reports Server (NTRS)

    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).

  11. Fluorine in meteorites

    NASA Technical Reports Server (NTRS)

    Allen, R. O., Jr.; Clark, P. J.

    1977-01-01

    Microanalysis using a resonant nuclear reaction was used to measure F concentrations in USGS standard rocks and 21 meteorites. The F appears to be a moderately depleted element, but there were significant variations within each sample. Measurements on separated metal phases suggest that about 20% of meteoritic F is in the metal or in a phase closely associated with it. Simultaneous measurements of F, Mg, Na, Al and Si in the nonmagnetic fractions of meteorites suggest plagioclase as a F containing phase.

  12. Foundations of Forensic Meteoritics

    NASA Astrophysics Data System (ADS)

    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

  13. Magnetism in meteorites

    NASA Technical Reports Server (NTRS)

    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.

  14. Fullerenes in Allende Meteorite

    NASA Technical Reports Server (NTRS)

    Becker, L.; Bada, J. L.; Winans, R. E.; Bunch, T. E.

    1994-01-01

    The detection of fullerenes in deposits from meteor impacts has led to renewed interest in the possibility that fullerenes are present in meteorites. Although fullerenes have not previously been detected in the Murchison and Allende meteorites, the Allende meteorite is known to contain several well-ordered graphite particles which are remarkably similar in size and appearance to the fullerene-related structures carbon onions and nanotubes. We report that fullerenes are in fact present in trace amounts in the Allende meteorite. In addition to fullerenes, we detected many polycyclic aromatic hydrocarbons (PAHs) in the Allende meteorite, consistent with previous reports. In particular, we detected benzofluoranthene and corannulene (C20H10), five-membered ring structures which have been proposed as precursors to the formation of fullerene synthesis, perhaps within circumstellar envelopes or other sites in the interstellar medium.

  15. Organic compounds in meteorites

    NASA Technical Reports Server (NTRS)

    Anders, E.; Hayatsu, R.; Studier, M. H.

    1973-01-01

    The problem of whether organic compounds originated in meteorites as a primary condensate from a solar gas or whether they were introduced as a secondary product into the meteorite during its residence in a parent body is examined by initially attempting to reconstruct the physical conditions during condensation (temperature, pressure, time) from clues in the inorganic matrix of the meteorite. The condensation behavior of carbon under these conditions is then analyzed on the basis of thermodynamic calculations, and compounds synthesized in model experiments on the condensation of carbon are compared with those actually found in meteorites. Organic compounds in meteorites seem to have formed by catalytic reactions of carbon monoxide, hydrogen, and ammonia in the solar nebula at 360 to 400 K temperature and about 3 to 7.6 microtorr pressure. The onset of these reactions was triggered by the formation of suitable catalysts (magnetite, hydrated silicates) at these temperatures.

  16. Obituary: Allan R. Sandage (1926-2010)

    NASA Astrophysics Data System (ADS)

    Devorkin, David

    2011-12-01

    Allan Rex Sandage died of pancreatic cancer at his home in San Gabriel, California, in the shadow of Mount Wilson, on November 13, 2010. Born in Iowa City, Iowa, on June 18, 1926, he was 84 years old at his death, leaving his wife, former astronomer Mary Connelly Sandage, and two sons, David and John. He also left a legacy to the world of astronomical knowledge that has long been universally admired and appreciated, making his name synonymous with late 20th-Century observational cosmology. The only child of Charles Harold Sandage, a professor of advertising who helped establish that academic specialty after obtaining a PhD in business administration, and Dorothy Briggs Sandage, whose father was president of Graceland College in Iowa, Allan Sandage grew up in a thoroughly intellectual, university oriented atmosphere but also a peripatetic one taking him to Philadelphia and later to Illinois as his father rose in his career. During his 2 years in Philadelphia, at about age eleven, Allan developed a curiosity about astronomy stimulated by a friend's interest. His father bought him a telescope and he used it to systematically record sunspots, and later attempted to make a larger 6-inch reflector, a project left uncompleted. As a teenager Allan read widely, especially astronomy books of all kinds, recalling in particular The Glass Giant of Palomar as well as popular works by Eddington and Hubble (The Realm of the Nebulae) in the early 1940s. Although his family was Mormon, of the Reorganized Church, he was not practicing, though he later sporadically attended a Methodist church in Oxford, Iowa during his college years. Sandage knew by his high school years that he would engage in some form of intellectual life related to astronomy. He particularly recalls an influential science teacher at Miami University in Oxford, Ohio named Ray Edwards, who inspired him to think critically and "not settle for any hand-waving of any kind." [Interview of Allan Rex Sandage by Spencer

  17. The Thermal and Radiation Exposure History of Lunar Meteorites

    NASA Technical Reports Server (NTRS)

    Benoit, Paul H.; Sears, Derek W. G.; Symes, Steven J. K.

    1996-01-01

    We have measured the natural and induced thermoluminescence (TL) of seven lunar meteorites in order to examine their crystallization, irradiation, and recent thermal histories. Lunar meteorites have induced TL properties similar to Apollo samples of the same provenance (highland or mare), indicating similar crystallization and metamorphic histories. MacAlplne Hills 88104/5 has experienced the greatest degree of impact/regolith processing among the highland-dominated meteorites. The basaltic breccia QUE 94281 is dominated by mare component but may also contain a significant highland component. For the mare-dominated meteorites, EET 87521 may have a significant highland impact-melt component, while Asuka 881757 and Y-793169 have been heavily shocked. The thermal history of Y-793169 included slow cooling, either during impact processing or during its initial crystallization. Our natural TL data indicate that most lunar meteorites have apparently been irradiated in space a few thousand years, with most less than 15,000 a. Elephant Moraine 87521 has the lowest irradiation exposure time, being less than 1,000 a. Either the natural TL of ALHA81005, Asuka 881757 and Y-82192 was only partially reset by lunar ejection or these meteorites were in small perihelia orbits (less than or equal to 0.7 AU).

  18. The mineralogy of meteorites.

    NASA Technical Reports Server (NTRS)

    Mason, B.

    1972-01-01

    Of particular interest among minerals recently discovered in meteorites are five phosphate minerals, three of them unknown in terrestrial rocks; a chromium nitride and a silicon oxynitride; lonsdaleite and chaoite, new polymorphs of carbon; ringwoodite and majorite, the spinel and garnet analogs of olivine and pyroxene, respectively; a number of calcium- and aluminum-rich silicates in the Allende meteorite, a type III carbonaceous chondrite which fell in 1969; and several alkali-rich silicates found as inclusions in iron meteorites. Knowledge of the compositional range of the common minerals olivine, pyroxene, and plagioclase has also been greatly increased by recent researches.

  19. Radiocarbon datings of Yamato meteorites

    NASA Technical Reports Server (NTRS)

    Kigoshi, K.; Matsuda, E.

    1986-01-01

    The terrestrial ages of five Yamato Meteorites were measured by the content of cosmic-ray-produced carbon-14. Three Yamato Meteorites Y-74013, Y-74097, and Y-74136, which are all diogenites, were found at sites from one to two kilometers apart from each other. Evidence is presented for these three meteorites being a single meteorite. Also presented is a method adopted in the experimental procedure which includes a check for modern carbon contamination in the meteorites.

  20. Fracture Characterization of Meteorites

    NASA Astrophysics Data System (ADS)

    Bryson, K. L.; Agrawal, P.; Ostrowski, D. R.; Sears, D. W. G.

    2015-07-01

    NASA ARC has been tasked with understanding the behavior of ~100m asteroids entering the atmosphere and quantifying the impact hazard. As part of this task, we report the initial results of a survey of the fracture properties of meteorites.

  1. Antimony in iron meteorites

    NASA Technical Reports Server (NTRS)

    Willis, J.

    1981-01-01

    Sb concentrations determined by radiochemical neutron activation analysis in 60 iron meteorites range from 0.2 ng/g to 36 microg/g. The meteorites with the highest Sb concentrations are those of the nonmagmatic groups IAB and IIICD, while meteorites with the lowest Sb concentrations are found in groups IVA and IVB. In all groups Sb is positively correlated with Ni; slopes on log Sb vs log Ni plots decrease with increasing Ni. This decrease may reflect an increasing tendency to avoid schreibersite during the analysis of high-Ni meteorites because Sb partitions strongly into schreibersite. It is found that schreibersite from New Westville is enriched in Cr, Ni, Ge, As, Sb, and Au and depleted in Fe, Co, Ir; the Sb content in schreibersite is 540 times higher than the bulk metal value.

  2. Cumberland Falls chondritic inclusions: III. Consortium study of relationship to inclusions in Allan Hills 78113 aubrite

    SciTech Connect

    Lipschutz, M.E.; Verkouteren, R.M. ); Sears, D.W.G.; Hasan, F.A. ); Prinz, M.; Weisberg, M.K.; Nehru, C.E.; Delaney, J.S. ); Grossman, L.; Boily, M. )

    1988-07-01

    The authors describe the mineralogy and report contents of Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Sb, Se, Te, Tl, U and Zn determined by RNAA in three primitive chondritic inclusions from the ALH A78113 aubrite. Comparison of these data with those for large, petrologic type 3 chondritic clasts from the Cumberland Falls aubrite and the discovery of small clasts in it like those in ALH A78113 indicate that all constitute a single chondritic suite. They report thermoluminescence data for Cumberland Falls chondritic inclusions and achondritic host. These results, together with mineralogic, major, minor and trace element information, demonstrate that aubrite inclusions represent a different sort of type 3 chondrite, not an LL3 chondrite altered during equilibration with aubrite host. Instead, the aubrite inclusions represent a distinct chondrite class. These inclusions reflect nebular condensation/accretion over a broad redox range and at temperatures relatively high compared with those at which other type 3 chondrites formed. Limited metamorphism and reduction occurred during condensation/accretion, prior to incorporation into aubrite host. During the impact of the chondritic parent body with the aubrite parent body, chondrite fragments were strongly shocked and cooled rapidly. They then mixed with aubrite host, possibly in a regolith, so that these aubrites now represent impact breccias.

  3. Rare Potassium-Bearing Mica in Allan Hills 84001: Additional Constraints on Carbonate Formation

    NASA Technical Reports Server (NTRS)

    Brearley, A. J.

    1998-01-01

    There have been presented several intriguing observations suggesting evidence of fossil life in martian orthopyroxenite ALH 84001. These exciting and controversial observations have stimulated extensive debate over the origin and history of ALH 84001, but many issues still remain unresolved. Among the most important is the question of the temperature at which the carbonates, which host the putative microfossils, formed. Oxygen- isotopic data, while showing that the carbonates are generally out of isotopic equilibria with the host rock, cannot constrain their temperature of formation. Both low- and high-temperature scenarios are plausible depending on whether carbonate growth occurred in an open or closed system. Petrographic arguments have generally been used to support a high-temperature origin but these appear to be suspect because they assume equilibrium between carbonate compositions that are not in contact. Some observations appear to be consistent with shock mobilization and growth from immiscible silicate-carbonate melts at high temperatures. Proponents of a low-temperature origin for the carbonates are hampered by the fact that there is currently no evidence of hydrous phases that would indicate low temperatures and the presence of a hydrous fluid during the formation of the carbonates. However, the absence of hydrous phases does not rule out carbonate formation at low temperatures, because the carbonate forming fluids may have been extremely CO2 rich, such that hydrous phases would not have been stabilized. In this study, I have carried out additional Transmission electron microscopy (TEM) studies of ALH-84001 and have found evidence of very rare phyllosilicates, which appear to be convincingly of pre-terrestrial origin. At present these observations are limited to one occurrence: further studies are in progress to determine if the phyllosilicates are more widespread.

  4. The Self According to Allan Bloom and Charles Reich.

    ERIC Educational Resources Information Center

    Aspy, David N.; Aspy, Cheryl B.

    1998-01-01

    Discusses the works of Charles Reich and Allan Bloom that have helped to shape current social and political debate concerning self theory. Both Reich and Bloom were concerned with the relationship between self and environment. Argues that it is important to insure that its cultural role of self theory is clearly interpreted and applied. (MKA)

  5. Biotechnology Symposium - In Memoriam, the Late Dr. Allan Zipf

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A one-day biotechnology symposium was held at Alabama A&M University (AAMU), Normal, AL on June 4, 2004 in memory of the late Dr. Allan Zipf (Sept 1953-Jan 2004). Dr. Zipf was a Research Associate Professor at the Department of Plant and Soil Sciences, AAMU, who collaborated extensively with ARS/MS...

  6. Allan Sandage : L'architecte de l'expansion

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.

    1998-07-01

    Il fut de cette poignee de pionniers qui ouvrirent le monde extragalactique. Depuis pres de 50 ans, Allan Sandage poursuit la quete amorcee par le "maitre" Edwin Hubble : mesurer le taux d'expansion de l'Univers. Rencontre avec une legende vivante de la cosmologie...

  7. Meteorite Seymchan structure

    NASA Astrophysics Data System (ADS)

    Hontsova, S. S.; Petrova, E. V.; Muftahetdinova, R. F.; Chulanova, V. N.; Grokhovsky, V. I.

    2016-09-01

    The meteorite Seymchan specimen was studied using optical microscopy and scanning electron microscopy. Olivine grains have roundish shapes, which was formed during matter cooling. Different features of the metal structure such as plessite structure and Neimann bands were observed. The oxide edges were observed in the boundaries between phases. The oxides were formed in the terrestrial conditions. The boundary regions between metal and olivine in the meteorite contain grains of troilite, schreibersite, and chromite.

  8. Meteorites, Microfossils and Exobiology

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.

    1997-01-01

    The discovery of evidence for biogenic activity and possible microfossils in a Martian meteorite may have initiated a paradigm shift regarding the existence of extraterrestrial microbial life. Terrestrial extremophiles that live in deep granite and hydrothermal vents and nanofossils in volcanic tuffs have altered the premise that microbial life and microfossils are inconsistent with volcanic activity and igneous rocks. Evidence for biogenic activity and microfossils in meteorites can no longer be dismissed solely because the meteoritic rock matrix is not sedimentary. Meteorite impact-ejection and comets provide mechanisms for planetary cross-contamination of biogenic chemicals, microfossils, and living microorganisms. Hence, previously dismissed evidence for complex indigenous biochemicals and possible microfossils in carbonaceous chondrites must be re-examined. Many similar, unidentifiable, biological-like microstructures have been found in different carbonaceous chondrites and the prevailing terrestrial contaminant model is considered suspect. This paper reports the discovery of microfossils indigenous to the Murchison meteorite. These forms were found in-situ in freshly broken, interior surfaces of the meteorite. Environmental Scanning Electron Microscope (ESEM) and optical microscopy images indicate that a population of different biological-like forms are represented. Energy Dispersive Spectroscopy reveals these forms have high carbon content overlaying an elemental distribution similar to the matrix. Efforts at identification with terrestrial microfossils and microorganisms were negative. Some forms strongly resemble bodies previously isolated in the Orgueil meteorite and considered microfossils by prior researchers. The Murchison forms are interpreted to represent an indigenous population of the preserved and altered carbonized remains (microfossils) of microorganisms that lived in the parent body of this meteorite at diverse times during the past 4.5 billion

  9. Organic Molecules in Meteorites

    NASA Astrophysics Data System (ADS)

    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 (<30%) consists of a rich organic inventory of soluble organic compounds, including key compounds important in terrestrial biochemistry [2-4]. Different carbonaceous 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

  10. Thermoluminescence and Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Sears, D. W. G.; Hasan, F. A.

    1986-01-01

    The level of natural thermoluminescence (TL) in meteorites is the result of competition between build-up, due to exposure to cosmic radiation, and thermal decay. Antarctic meteorites tend to have lower natural TL than non-Antarctic meteorites because of their generally larger terrestrial ages. However, since a few observed falls have low TL due to a recent heating event, such as passage within approximately 0.7 astronomical units of the Sun, this could also be the case for some Antarctic meteorites. Dose rate variations due to shielding, heating during atmospheric passage, and anomalous fading also cause natural TL variations, but the effects are either relatively small, occur infrequently, or can be experimentally circumvented. The TL sensitivity of meteorites reflects the abundance and nature of the feldspar. Thus intense shock, which destroys feldspar, causes the TL sensitivity to decrease by 1 to 2 orders of magnitude, while metamorphism, which generates feldspar through the devitrification of glass, causes TL sensitivity to increase by a factor of approximately 10000. The TL-metamorphism relationship is particularly strong for the lowest levels of metamorphism. The order-disorder transformation in feldspar also affect the TL emission characteristics and thus TL provides a means of paleothermometry.

  11. Meteorite fusion crust variability.

    NASA Astrophysics Data System (ADS)

    Thaisen, Kevin G.; Taylor, Lawrence A.

    2009-06-01

    Two assumptions commonly employed in meteorite interpretation are that fusion crust compositions represent the bulk-rock chemistry of the interior meteorite and that the vesicles within the fusion crust result from the release of implanted solar wind volatiles. Electron microprobe analyses of thin sections from lunar meteorite Miller Range (MIL) 05035 and eucrite Bates Nunataks (BTN) 00300 were performed to determine if the chemical compositions of the fusion crust varied and/or represented the published bulk rock composition. It was determined that fusion crust compositions are significantly influenced by the incorporation of fragments from the substrate, and by the composition and grain size of those minerals. Because of compositional heterogeneities throughout the meteorite, one cannot assume that fusion crust composition represents the bulk rock composition. If the compositional variability within the fusion crust and mineralogical differences among thin sections goes unnoticed, then the perceived composition and petrogenetic models of formation will be incorrect. The formation of vesicles within these fusion crusts were also compared to current theories attributing vesicles to a solar wind origin. Previous work from the STONE-5 experiment, where terrestrial rocks were exposed on the exterior of a spacecraft heatshield, produced a vesicular fusion crust without prolonged exposure to solar wind suggesting that the high temperatures experienced by a meteorite during passage through the Earth's atmosphere are sufficient to cause boiling of the melt. Therefore, the assumption that all vesicles found within a fusion crust are due to the release of implanted volatiles of solar wind may not be justified.

  12. Meteorites on Mars observed with Mars Exploration Rovers

    USGS Publications Warehouse

    Schroder, C.; Rodionov, D.S.; McCoy, T.J.; Jolliff, B.L.; Gellert, Ralf; Nittler, L.R.; Farrand, W. H.; Johnson, J. R.; Ruff, S.W.; Ashley, James W.; Mittlefehldt, D. W.; Herkenhoff, K. E.; Fleischer, I.; Haldemann, A.F.C.; Klingelhofer, G.; Ming, D. W.; Morris, R.V.; de Souza, P.A.; Squyres, S. W.; Weitz, C.; Yen, A. S.; Zipfel, J.; Economou, T.

    2008-01-01

    Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density of meteorites on the surface of Mars compared to Earth. Several meteorites were identified among the rocks investigated during Opportunity's traverse across the sandy Meridiani plains. Heat Shield Rock is a IAB iron meteorite and has been officially recognized as 'Meridiani Planum.' Barberton is olivine-rich and contains metallic Fe in the form of kamacite, suggesting a meteoritic origin. It is chemically most consistent with a mesosiderite silicate clast. Santa Catarina is a brecciated rock with a chemical and mineralogical composition similar to Barberton. Barberton, Santa Catarina, and cobbles adjacent to Santa Catarina may be part of a strewn field. Spirit observed two probable iron meteorites from its Winter Haven location in the Columbia Hills in Gusev Crater. Chondrites have not been identified to date, which may be a result of their lower strengths and probability to survive impact at current atmospheric pressures. Impact craters directly associated with Heat Shield Rock, Barberton, or Santa Catarina have not been observed, but such craters could have been erased by eolian-driven erosion. Copyright 2008 by the American Geophysical Union.

  13. The Meteoritical Bulletin, No. 101

    NASA Astrophysics Data System (ADS)

    Ruzicka, Alex; Grossman, Jeffrey; Bouvier, Audrey; Herd, Christopher D. K.; Agee, Carl B.

    2015-09-01

    Meteoritical Bulletin 101 contains 2639 meteorites accepted by the Nomenclature Committee in 2012, including 1 fall (Battle Mountain), with 2308 ordinary chondrites, 156 carbonaceous chondrites, 63 HED achondrites, 17 relict meteorites, 16 Rumuruti chondrites, 15 enstatite chondrites, 15 ureilites, 10 iron meteorites, 9 lunar meteorites, 9 primitive achondrites, 8 ungrouped achondrites, 7 mesosiderites, 4 Martian meteorites, and 2 Pallasites, and with 1812 from Antarctica, 437 from Asia, 301 from Africa, 43 from South America, 21 from Europe (including Russia), 21 from North America, 3 from Oceania, and 1 from unknown. Information about approved meteorites can be obtained from the Meteoritical Bulletin Database (MBD) available on line at http://www.lpi.usra.edu/meteor/.

  14. Antarctic Meteorite Newsletter. Volume 20

    NASA Technical Reports Server (NTRS)

    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.

  15. The relict magnetism of meteorites

    NASA Technical Reports Server (NTRS)

    Cisowski, S. M.; Hood, L. L.

    1991-01-01

    Meteorite paleomagnetic studies are reviewed and evaluated. Possible mechanisms for producing early solar system magnetic fields that could have been responsible for the magnetization of some or all meteorite classes are explored. A detailed review of paleointensity results derived from the various classes of meteorites is given, and the likelihood that the results might related to solar or nebulawide magnetic fields is considered. The implications of meteorite magnetism for early solar system evolution are discussed.

  16. Organic Chemistry of Meteorites

    NASA Technical Reports Server (NTRS)

    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.

  17. Primordial material in meteorites

    NASA Technical Reports Server (NTRS)

    Kerridge, J. F.

    1986-01-01

    Primordial is a term which applied to material that entered the solar system early and became incorporated into a meteorite without totally losing its identity. Identification of such material surviving in meteorites is so far solely through recognition of anomalous isotopic compositions of generally macroscopic entities contained within those meteorites. Isotopic anomalies are, by definition, isotopic compositions which differ from the canonical solar system abundances in ways which cannot be explained in terms of local processes such as mass dependent fractionation, cosmic ray induced spallation or decay of radionuclides. A comprehensive account of isotopic anomalies is impractical here, so it is necessary to be selective. Issues which are potentially addressable through the study of such primordial material are examined. Those issues will be illustrated with specific, but not exhaustive, examples.

  18. Organics In Meteorites

    NASA Technical Reports Server (NTRS)

    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.

  19. Meteorites and their parent planets

    NASA Astrophysics Data System (ADS)

    McSween, Harry Y.

    This book explores the origins of meteorites by tracing them back to their parent bodies, which are the sites of various geological processes. Recent discoveries are reviewed which reveal that the chemical and physical properties of meteorites contain a record of the processes that formed the solar system. How meteorites escape their parent bodies and find their way to earth is explained.

  20. Iron Meteorite on Mars

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA's Mars Exploration Rover Opportunity has found an iron meteorite on Mars, the first meteorite of any type ever identified on another planet. The pitted, basketball-size object is mostly made of iron and nickel. Readings from spectrometers on the rover determined that composition. Opportunity used its panoramic camera to take the images used in this approximately true-color composite on the rover's 339th martian day, or sol (Jan. 6, 2005). This composite combines images taken through the panoramic camera's 600-nanometer (red), 530-nanometer (green), and 480-nanometer (blue) filters.

  1. Microfossils in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.

    2009-01-01

    Microfossils of large filamentous trichomic prokaryotes have been detected during in-situ investigations of carbonaceous meteorites. This research has been carried out using the Field Emission Scanning Electron Microscope (FESEM) to examine freshly fractured interior surfaces of the meteorites. The images obtained reveal that many of these remains are embedded in the meteorite rock matrix. Energy Dispersive X-Ray Spectroscopy (EDS) studies establish that the filamentous microstructures have elemental compositions consistent with the meteorite matrix, but are often encased within carbon-rich electron transparent sheath-like structures infilled with magnesium sulfate. This is consistent with the taphonomic modes of fossilization of cyanobacteria and sulphur bacteria, since the life habits and processes of these microorganisms frequently result in distinctive chemical biosignatures associated with the properties of their cell-walls, trichomes, and the extracellular polymeric substances (EPS) of the sheath. In this paper the evidence for biogenicity presented includes detailed morphological and morphometric data consistent with known characteristics of uniseriate and multiseriate cyanobacteria. Evidence for indigeneity includes the embedded nature of the fossils and elemental compositions inconsistent with modern biocontaminants.

  2. Carbon in primitive meteorites

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.

    1990-01-01

    No meteorites are truly primitive, in the sense of being pristine collections of interstellar grains or solar-nebular condensates. Nonetheless, some chrondritic meteorites have been so little altered by secondary processing that they are commonly termed primitive and it is almost a definition of such chondrites that they contain significant quantities of carbon. Most of that carbon is of apparently local, i.e., solar-system, origin but a proportion that ranges from trace, in some cases, to minor, in others, is believed to be exotic, i.e., of circumstellar or interstellar origin, and it is upon such material that researchers focus here. The nature of the meteoritic samples and the techniques used to analyse them are briefly discussed and the observational record is surveyed. Clearly, the study of exotic carbon preserved in meteorites has been informative about sites of nucleosynthesis, processes of nucleation and growth of grains in stellar outflows, grain survival in the interstellar medium, and many other topics of astrophysical significance. Much more work, particularly of an interdisciplinary nature remains to be done, however.

  3. Microfossils in carbonaceous meteorites

    NASA Astrophysics Data System (ADS)

    Hoover, Richard B.

    2009-08-01

    Microfossils of large filamentous trichomic prokaryotes have been detected during in-situ investigations of carbonaceous meteorites. This research has been carried out using the Field Emission Scanning Electron Microscope (FESEM) to examine freshly fractured interior surfaces of the meteorites. The images obtained reveal that many of these remains are embedded in the meteorite rock matrix. Energy Dispersive X-Ray Spectroscopy (EDS) studies establish that the filamentous microstructures have elemental compositions consistent with the meteorite matrix, but are often encased within carbon-rich electron transparent sheath-like structures infilled with magnesium sulfate. This is consistent with the taphonomic modes of fossilization of cyanobacteria and sulphur bacteria, since the life habits and processes of these microorganisms frequently result in distinctive chemical biosignatures associated with the properties of their cell-walls, trichomes, and the extracellular polymeric substances (EPS) of the sheath. In this paper the evidence for biogenicity presented includes detailed morphological and morphometric data consistent with known characteristics of uniseriate and multiseriate cyanobacteria. Evidence for indigeneity includes the embedded nature of the fossils and elemental compositions inconsistent with modern bio-contaminants.

  4. Geochemistry of the Martian meteorite ALH84001, revisited

    NASA Astrophysics Data System (ADS)

    Barrat, Jean-Alix; Bollinger, Claire

    2010-04-01

    Major and trace element abundances were determined on powders prepared from four distinct chips from Allan Hills (ALH) 84001 to constrain the bulk rock composition, and to assess the trace element abundances of orthopyroxenes and phosphates. Our new determinations were used to evaluate the composition of the parental melt of this stone. An unrealistic light rare earth element (REE)-enriched parental melt is calculated from the composition of the orthopyroxene and relevant equilibrium partition coefficients. The involvement of a small amount of trapped melt and subsolidus reequilibrations between orthopyroxene and the interstitial phases can account for this discrepancy. A parental melt that displays a trace element pattern (REE, Zr, and Hf) that closely resembles enriched shergottites such as Zagami or Los Angeles is calculated if these effects are taken into account. These results suggest that some shergottitic melts were already erupted on Mars during the Noachian.

  5. Mineralogy of Meteorite Groups

    NASA Technical Reports Server (NTRS)

    Rubin, Alan E.

    1997-01-01

    Approximately 275 mineral species have been identified in meteorites, reflecting diverse redox environments, and, in some cases, unusual nebular formation conditions. Anhydrous ordinary, carbonaceous and R chondrites contain major olivine, pyroxene and plagioclase; major opaque phases include metallic Fe-Ni, troilite and chromite. Primitive achondrites are mineralogically similar. The highly reduced enstatite chondrites and achondrites contain major enstatite, plagioclase, free silica and kamacite as well as nitrides, a silicide and Ca-, Mg-, Mn-, Na-, Cr-, K- and Ti-rich sulfides. Aqueously altered carbonaceous chondrites contain major amounts of hydrous phyllosilicates, complex organic compounds, magnetite, various sulfates and sulfides, and carbonates. In addition to kamacite and taenite, iron meteorites contain carbides, elemental C, nitrides, phosphates, phosphides, chromite and sulfides. Silicate inclusions in IAB/IIICD and lIE iron meteorites consist of mafic silicates, plagioclase and various sulfides, oxides and phosphates. Eucrites, howardites and diogenites have basaltic to orthopyroxenitic compositions and consist of major pyroxene and calcic plagioclase and several accessory oxides. Ureilttes .are made up mainly of calcic, chromian olivine and low-Ca clinopyroxene embedded in a carbonaceous matrix; accessory phases include the C polymorphs graphite, diamond, lonsdaleite and chaoite as well as metallic Fe-Ni, troilite and halides. Angrites are achondrites rich in fassaitic pyroxene (i.e. , AI-Ti diopside); minor olivine with included magnesian kirschsteinite is also present. Martian meteorites comprise basalts, Iherzolites, a dunite and an orthopyroxenite. Major phases include various pyroxenes and olivine; minor to accessory phases include various sulfides, magnetite, chromite and Ca-phosphates. Lunar meteorites comprise mare basalts with major augite and calcic plagioclase and anorthositic breccias with major calcic plagioclase. Several meteoritic

  6. The Meteoritical Bulletin, No. 102

    NASA Astrophysics Data System (ADS)

    Ruzicka, Alex; Grossman, Jeffrey; Bouvier, Audrey; Herd, Christopher D. K.; Agee, Carl B.

    2015-09-01

    Meteoritical Bulletin 102 contains 3141 meteorites including 12 falls (Boumdeid (2003), Boumdeid (2011), Braunschweig, Chelyabinsk, Dongyang, Draveil, Heyetang, Indian Butte, Katol, Ladkee, Ouadangou, Xining), with 2611 ordinary chondrites, 264 HED achondrites, 124 carbonaceous chondrites, 30 ureilites, 20 Martian meteorites, 16 primitive achondrites, 16 Rumuruti chondrites, 15 mesosiderites, 12 iron meteorites, 10 lunar meteorites, 9 enstatite chondrites, 4 enstatite achondrites, 4 Pallasites, 4 ungrouped achondrites, and 2 angrites, and with 1708 from Antarctica, 956 from Africa, 294 from South America, 126 from Asia, 47 from North America, 6 from Europe (including Russia), and 4 from Oceania. Information about approved meteorites can be obtained from the Meteoritical Bulletin Database (MBD) available on line at http://www.lpi.usra.edu/meteor/.

  7. Huge waves of meteorite origin

    NASA Astrophysics Data System (ADS)

    Pelinovsky, Efim; Kozelkov, Andrey; Kurkin, Andrey

    2016-04-01

    Asteroid and meteorite risk is now actively investigated in various aspects. If the meteorite falls in the ocean it can generate huge waves with heights exceeded 10 m. For whole history about 10-20 events related with entry of meteorite in water are known. The last event occurred on February 15, 2013 when the meteorite exploded in sky of Chelyabinsk (Russia) and its big piece entered in the Chebarkul Lake. Very often, huge waves of meteorite origin are computed using the conception of equivalent (parametrical) source, whose parameters are determined through meteorite characteristics. Recently, direct methods based on numerical simulations of the Reynolds-averaged Navier-Stokes equations (RANS) have been applied to study wave processes generated by the entry of meteorite. These approaches and their applications to the historic events are discussed in paper.

  8. Chiral Biomarkers in Meteorites

    NASA Technical Reports Server (NTRS)

    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

  9. Hydrocarbon components in carbonaceous meteorites

    NASA Astrophysics Data System (ADS)

    Kissin, Y. V.

    2003-05-01

    Currently, the presence of free n-alkanes and isoprenoid alkanes in carbonaceous meteorites is usually explained either by microbial contamination during the period between the meteorite fall and collection or by contamination from the environment of analytical laboratories and museums. The goal of this research was to repeat analysis of hydrocarbon components in meteorites and to investigate possible meteorite contamination routes discussed in the literature. Experimental analysis of free organic constituents in five carbonaceous meteorites by infrared spectroscopy (IR) and gas chromatographic (GC) methods confirmed the presence of extractable aliphatic components, n-alkanes in the C 15H 32-C 27H 56 range and isoprenoid alkanes (phytane, pristane, and norpristane), in some of these meteorites. The contents of these compounds vary depending on the source. Insoluble organic components of two meteorites (meteorite kerogens) were isolated, and their composition was analyzed by IR and cracking/GC methods. Comparison with the data on several terrestrial contamination sources proposed in the literature shows that the presence of free saturated hydrocarbons in meteorites and the composition of the meteorite kerogen could not be explained either by microbial contamination or by contamination from the laboratory environment. The types of the hydrocarbons in meteorites resemble those typical of ancient terrestrial deposits of organic-rich sediments, except for the absence of lighter hydrocarbons, which apparently slowly evaporated in space, and multi-ring naphthenic compounds of the biologic origin, steranes, terpanes, etc. The prevailing current explanation for the presence of free linear saturated hydrocarbons in carbonaceous meteorites, apart from contamination, is the abiotic route from hydrogen and carbon monoxide. However, the data on the structure of meteorite kerogens require a search for different routes that initially produce complex polymeric structures containing

  10. Recent documented meteorite falls, a review of meteorite - asteroid links

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.

    2014-07-01

    Since the previous Meteoroids 2010 meeting, 25 confirmed meteorite falls have been reported, and one additional meteorite was linked tentatively to an observed fireball. All but two of those are classified as ordinary chondrites. Sutter's Mill is a rare carbonaceous chondrite, while Martian meteorite Tissint is a Shergotite. For 18 of these falls the associated fireball was observed, but only four provided a pre-atmospheric orbit derived from video and photographic records. Results were published for Sutter's Mill, Novato, and Chelyabinsk, providing insight into the asteroid belt source regions for CM2, L and LL type chondrites, respectively. Proposed meteorite-asteroid links are discussed.

  11. Organic chemistry in meteorites

    NASA Astrophysics Data System (ADS)

    Botta, Oliver

    2002-11-01

    Carbonaceous chondrites contain a suite of soluble organic compounds that possess characteristics that help to understand their formation and to trace back the early history of the solar system. Relative amino acid abundances can be used to discriminate between different parent bodies. The Tagish Lake meteorite is a unique sample from a new type of solar system object that will help to further constrain the physical and chemical conditions found on parent bodies. Enantiomeric excesses have been detected in nonbiological amino acids in the Murchison and Murray meteorites that are still difficult to explain in the current scenario for the synthesis of extraterrestrial amino acids. Finally, new classes of compounds, dipeptides and sugar-related molecules, have been detected in CM carbonaceous chondrites.

  12. Pragmatics: The State of the Art: An Online Interview with Keith Allan

    ERIC Educational Resources Information Center

    Allan, Keith; Salmani Nodoushan, Mohammad Ali

    2015-01-01

    This interview was conducted with Professor Keith Allan with the aim of providing a brief but informative summary of the state of the art of pragmatics. In providing answers to the interview questions, Professor Allan begins with a definition of pragmatics as it is practiced today, i.e., the study of the meanings of utterances with attention to…

  13. The dynamic Allan Variance IV: characterization of atomic clock anomalies.

    PubMed

    Galleani, Lorenzo; Tavella, Patrizia

    2015-05-01

    The number of applications where precise clocks play a key role is steadily increasing, satellite navigation being the main example. Precise clock anomalies are hence critical events, and their characterization is a fundamental problem. When an anomaly occurs, the clock stability changes with time, and this variation can be characterized with the dynamic Allan variance (DAVAR). We obtain the DAVAR for a series of common clock anomalies, namely, a sinusoidal term, a phase jump, a frequency jump, and a sudden change in the clock noise variance. These anomalies are particularly common in space clocks. Our analytic results clarify how the clock stability changes during these anomalies.

  14. The dynamic Allan Variance IV: characterization of atomic clock anomalies.

    PubMed

    Galleani, Lorenzo; Tavella, Patrizia

    2015-05-01

    The number of applications where precise clocks play a key role is steadily increasing, satellite navigation being the main example. Precise clock anomalies are hence critical events, and their characterization is a fundamental problem. When an anomaly occurs, the clock stability changes with time, and this variation can be characterized with the dynamic Allan variance (DAVAR). We obtain the DAVAR for a series of common clock anomalies, namely, a sinusoidal term, a phase jump, a frequency jump, and a sudden change in the clock noise variance. These anomalies are particularly common in space clocks. Our analytic results clarify how the clock stability changes during these anomalies. PMID:25965674

  15. Antarctic meteorite descriptions, 1980

    NASA Technical Reports Server (NTRS)

    Score, R.; Schwarz, C. M.; Mason, B.; Bogard, D. D.

    1982-01-01

    Specimens found in the Alan Hills area include 361 ordinary chondrites, 4 carbonaceous chondrites, 6 achondrites, and 2 irons. Thirteen specimens measured over 11 cm in diameter and 69 between 5 to 10 cm in diameter are reported. The remainder of the finds were small, and many were paired. One of the irons was estimated to weigh about 20 kilograms.

  16. Hexagonal diamonds in meteorites: implications.

    PubMed

    Hanneman, R E; Strong, H M; Bundy, F P

    1967-02-24

    A new polymorph of carbon, hexagonal diamond, has been discovered in the Canyon Diablo and Goalpara meteorites. This phase had been synthesized recently under specific high-pressure conditions in the laboratory. Our results: provide strong evidence that diamonds found in these meteorites were produced by intense shock pressures acting on crystalline graphite inclusions present within the meteorite before impact, rather than by disintegration of larger, statically grown diamonds, as some theories propose. PMID:17830485

  17. Meteorites from Cluj-Napoca

    NASA Astrophysics Data System (ADS)

    Radu, Gelu; Pop, Dana

    2003-04-01

    The article represents an interview of the journalist Gelu Radu with the director of the Meteorites Museum from the Geological Faculty of the Cluj-Napoca University (Romania) Dana Pop concerning the History, Collection and Actual state of an unique in Romania Meteorites Museum, founded in 1882 after the fall of the Mociu Meteorit (Cluj County) on 3 february 1882. One discusses about the collection of the Museum and the policy of changes with other similar museums throughout the world.

  18. Iron Meteorites and Upwelling in Antarctica

    NASA Astrophysics Data System (ADS)

    Gourlay, B. S.; Behr, E.; Mardon, A.; Behr, E.

    2016-09-01

    In Antarctica, a meteorite stranding zone, stone meteorites are more common than iron. Dr. Evatt's team suggests that the heat conductivity of iron may be opposing the upwelling effects so iron meteorites sink under the ice unlike the stone ones.

  19. David Keynes Hill.

    PubMed

    Huxley, Andrew

    2003-01-01

    David Hill followed his father, A.V. Hill FRS, into the study of muscular contraction. Using a wide range of experimental techniques, he made several important advances of which the most important was the discovery of the 'short-range elastic component', a phenomenon which implied that even in the resting state there was an interaction between the thick (myosin) and thin (actin) filaments. He also studied physical changes in nerve when stimulated.

  20. Amino and fatty acids in carbonaceous meteorites

    NASA Technical Reports Server (NTRS)

    Kvenvolden, K. A.

    1974-01-01

    Analyses of two carbonaceous meteorites have provided much of the latest evidence which seems to support Oparin's theory on the origin of life. The meteorites involved are the Murray meteorite, which fell in 1950, and the Murchison meteorite, which fell in 1969. The amino acids in the two meteorites are similar in composition. Eight of the twenty amino acids found belong to amino acids present in proteins. A number of monocarboxylic and dicarboxylic fatty acids were also found in the meteorites.

  1. The Merna, Nebraska Meteorite Crater

    NASA Astrophysics Data System (ADS)

    Povenmire, H.

    1995-09-01

    This crater-like structure was recognized by geomorphologist, Wakefield Dort in 1992 while examining topographic maps [1]. Using the same tradition as for meteorite discoveries, he named it after the nearest town with a post office, Merna, Nebraska, Zip code, 68856. This researcher has made two extensive field trips to the crater. The f1rst was to examine and confirm its nature and the second to field check the results after a computer simulation of the impacting projectile. This area is characterized by low rolling hills which are under cultivation. This area is unglaciated and the closest recent glacial approach was about 240 km. The prevailing winds are from the northwest and there are many parallel eolian features which have an azimuth of approximately 300 degrees. The predominate erosional factors are snowmelt and the spring rains. Most of the 53 cm annual precipitation occurs from March to May. The soil is predominantly Peoria loess with an estimated depth of approximately 260 m.[2]. This is probably underlaid with limestone bedrock. Well records of the area have not been very helpful in resolving this question. The Merna Crater is an approximately 1.6 km diameter, 23 m deep, well preserved depression with a flat bottom. It is located about 18 km west of and 2.4 km south of Merna, Nebraska. This site is on the U.S.G.S. 7.'5 Callaway N.W., Nebraska 1951 topographic map. The crater covers most of section 9 and the eastern portion of section 8. The coordinates of the crater center are approximately longitude 99 degrees 58' 20"W and latitude 41 degrees 27' 30" N. A significant landmark on section 9 is the Cliff Union Church and Cemetery which is on the eastern rim of the crater. Even though the land has been plowed for more than 150 years, the general topographic features have not been seriously disturbed. It is believed that the crater was caused by an air blast similar to Tunguska but of a much larger magnitude. It is therefore believed that there never was a

  2. Princess Marie Bonaparte, Edgar Allan Poe, and psychobiography.

    PubMed

    Warner, S L

    1991-01-01

    Princess Marie Bonaparte was a colorful yet mysterious member of Freud's inner circle of psychoanalysis. In analysis with Freud beginning in 1925 (she was then 45 years old), she became a lay analyst and writer of many papers and books. Her most ambitious task was a 700-page psychobiography of Edgar Allan Poe that was first published in French in 1933. She was fascinated by Poe's gothic stories--with the return to life of dead persons and the eerie, unexpected turns of events. Her fascination with Poe can be traced to the similarity of their early traumatic life experiences. Bonaparte had lost her mother a month after her birth. Poe's father deserted the family when Edgar was two years old, and his mother died of tuberculosis when he was three. Poe's stories helped him to accommodate to these early traumatic losses. Bonaparte vicariously shared in Poe's loss and the fantasies of the return of the deceased parent in his stories. She was sensitive and empathetic to Poe's inner world because her inner world was similar. The result of this psychological fit between Poe and Bonaparte was her psychobiography, The Life and Works of Edgar Allan Poe. It was a milestone in psychobiography but limited in its psychological scope by its strong emphasis on early childhood trauma. Nevertheless it proved Bonaparte a bona fide creative psychoanalyst and not a dilettante propped up by her friendship with Freud.

  3. Meteorite Atmospheric Entry Reproduced in Plasmatron

    NASA Astrophysics Data System (ADS)

    Pittarello, L.; McKibbin, S.; Goderis, S.; Soens, B.; Bariselli, F.; Barros Dias, B. R.; Zavalan, F. L.; Magin, T.; Claeys, Ph.

    2016-08-01

    Plasmatron facility allows experimental conditions that reproduce atmospheric entry of meteorites. Tests on basalt, as meteorite analogue, have been performed. Preliminary results have highlighted melting and evaporation effects.

  4. Comets, meteorites and atmospheres.

    PubMed

    Owen, T; Bar-Nun, A

    1996-01-01

    The relatively low value of Xe/Kr in the atmospheres of Earth and Mars seems to rule out meteorites as the major carriers of noble gases to the inner planets. Laboratory experiments on the trapping of gases in ice forming at low temperatures suggest that comets may be a better choice. It is then possible to develop a model for the origin of inner planet atmospheres based on volatiles delivered by comets added to volatiles originally trapped in planetary rocks. The model will be tested by results from the Galileo Entry Probe.

  5. Meteorite regolithic breccias

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Rajan, R. S.

    1988-01-01

    In addition to endogenic processes such as heating and aqueous activity, meteorite parent bodies were subjected also to exogenic processing brought about by the impact of the other solar-system objects. Such impacts can produce a variety of effects, ranging from shock metamorphism of individual mineral grains to production of breccias; i.e., rocks consisting of mixtures of disparate lithic units. The present paper reviews recent studies of such breccias, which have generated significant information about the accretional growth of parent bodies, as well as their evolution, composition, stratigraphy, and geological processing.

  6. Stardust in meteorites

    PubMed Central

    Davis, Andrew M.

    2011-01-01

    Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in exquisite detail with modern analytical tools. The properties of stardust grains are used to constrain models of nucleosynthesis in red giant stars and supernovae, the dominant sources of dust grains that are recycled into the interstellar medium by stars. PMID:22106261

  7. Stardust in meteorites.

    PubMed

    Davis, Andrew M

    2011-11-29

    Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in exquisite detail with modern analytical tools. The properties of stardust grains are used to constrain models of nucleosynthesis in red giant stars and supernovae, the dominant sources of dust grains that are recycled into the interstellar medium by stars. PMID:22106261

  8. Comets, meteorites and atmospheres

    NASA Technical Reports Server (NTRS)

    Owen, T.; Bar-Nun, A.

    1996-01-01

    The relatively low value of Xe/Kr in the atmospheres of Earth and Mars seems to rule out meteorites as the major carriers of noble gases to the inner planets. Laboratory experiments on the trapping of gases in ice forming at low temperatures suggest that comets may be a better choice. It is then possible to develop a model for the origin of inner planet atmospheres based on volatiles delivered by comets added to volatiles originally trapped in planetary rocks. The model will be tested by results from the Galileo Entry Probe.

  9. Stardust in meteorites.

    PubMed

    Davis, Andrew M

    2011-11-29

    Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in exquisite detail with modern analytical tools. The properties of stardust grains are used to constrain models of nucleosynthesis in red giant stars and supernovae, the dominant sources of dust grains that are recycled into the interstellar medium by stars.

  10. Magnetic record in chondrite meteorites

    NASA Technical Reports Server (NTRS)

    Wasilewski, P. J.; Faris, J. L.; Obryan, M. V.

    1993-01-01

    What we know about the magnetic record in chondrite meteorites based on new data and previously published results is summarized. Strips from thin slabs of chondrite meteorites were cut into near cubical subsamples (several mm on edge) numbering approximately 60 to approximately 120 per meteorite. A common orientation was assigned to each subsample from a given meteorite in order to ensure that we could discover the vector makeup of the bulk meteorite. The new data set includes: Shaw (L7), Roy (L5/6), Claytonville (L5), Plainview (H5), Etter (H5), Leoville (C3V), and Allende (C3V). In addition to these new results, literature data of sufficient detail, e.g. Bjurbole (L4), ALH769 (L6), Abee (E4), Allende (C3V), and Olivenza (L5), is considered.

  11. The Mbale meteorite shower

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Betlem, Hans; Betlem, Jan; Barifaijo, Erasmus; Schluter, Thomas; Hampton, Craig; Laubenstien, Matthias; Kunz, Joachim; Heusser, Gerd

    1994-01-01

    On 1992 August 14 at 12:40 UTC, an ordinary chondrite of type L5/6 entered the atmosphere over Mbale, Uganda, broke up, and caused a strewn field of size 3 x 7 km. Shortly after the fall, an expedition gathered eye witness accounts and located the position of 48 impacts of masses between 0.19 and 27.4 kg. Short-lived radionuclide data were measured for two specimens, one of which was only 12 days after the fall. Subsequent recoveries of fragements has resulted in a total of 863 mass estimates by 1993 October. The surfaces of all fragments contain fusion crust. The meteorite shower caused some minor inconveniences. Most remarkably, a young boy was hit on the head by a small specimen. The data interpreted as to indicate that the meteorite had an initial mass between 400-1000 kg (most likely approximately 1000 kg) and approached Mbale from AZ = 185 +/- 15, H = 55 +/- 15, and V(sub infinity) = 13.5 +/- 1.5/s. Orbital elements are given. Fragmentation of the initial mass started probably above 25 km altitude, but the final catastrophic breakup occurred at an altitude of 10-14 km. An estimated 190 +/- 40 kg reached the Earth's surface minutes after the final breakup of which 150 kg of material has been recovered.

  12. Meteoritic Sulfur Isotopic Analysis

    NASA Technical Reports Server (NTRS)

    Thiemens, Mark H.

    1996-01-01

    Funds were requested to continue our program in meteoritic sulfur isotopic analysis. We have recently detected a potential nucleosynthetic sulfur isotopic anomaly. We will search for potential carriers. The documentation of bulk systematics and the possible relation to nebular chemistry and oxygen isotopes will be explored. Analytical techniques for delta(sup 33), delta(sup 34)S, delta(sup 36)S isotopic analysis were improved. Analysis of sub milligram samples is now possible. A possible relation between sulfur isotopes and oxygen was detected, with similar group systematics noted, particularly in the case of aubrites, ureilites and entstatite chondrites. A possible nucleosynthetic excess S-33 has been noted in bulk ureilites and an oldhamite separate from Norton County. High energy proton (approximately 1 GeV) bombardments of iron foils were done to experimentally determine S-33, S-36 spallogenic yields for quantitation of isotopic measurements in iron meteorites. Techniques for measurement of mineral separates were perfected and an analysis program initiated. The systematic behavior of bulk sulfur isotopes will continue to be explored.

  13. Meteors and meteorites spectra

    NASA Astrophysics Data System (ADS)

    Koukal, J.; Srba, J.; Gorková, S.; Lenža, L.; Ferus, M.; Civiš, S.; Knížek, A.; Kubelík, P.; Kaiserová, T.; Váňa, P.

    2016-01-01

    The main goal of our meteor spectroscopy project is to better understand the physical and chemical properties of meteoroids. Astrometric and spectral observations of real meteors are obtained via spectroscopic CCD video systems. Processed meteor data are inserted to the EDMOND database (European viDeo MeteOr Network Database) together with spectral information. The fully analyzed atmospheric trajectory, orbit and also spectra of a Leonid meteor/meteoroid captured in November 2015 are presented as an example. At the same time, our target is the systematization of spectroscopic emission lines for the comparative analysis of meteor spectra. Meteoroid plasma was simulated in a laboratory by laser ablation of meteorites samples using an (ArF) excimer laser and the LIDB (Laser Induced Dielectric Breakdown) in a low pressure atmosphere and various gases. The induced plasma emissions were simultaneously observed with the Echelle Spectrograph and the same CCD video spectral camera as used for real meteor registration. Measurements and analysis results for few selected meteorite samples are presented and discussed.

  14. The Kosice meteorite

    NASA Astrophysics Data System (ADS)

    Toth, J.; Svoren, J.

    2012-01-01

    The glare of the bolide on the night of February 28, 2010, illuminated streets and interiors of apartments at some location in eastern Slovakia and northern Hungary. In addition, cannon-like bursts or series of low frequency blasts were heard. Due to bad weather, cloudy skies, and scattered showers, the Central European Fireball Network (operated by Dr. Pavel Spurny of the Czech Academy of Sciences) did not take direct optical records of the bolide and the Slovak Video Meteor Network (operated by the first author) was not operational that night. So, at first sight, it seemed that there were no scientific records of this event. Fortunately, fast photoelectric sensors on seven automated fireball stations in the Czech Republic (6) and Austria (1) detected the illumination of the sky caused by the bolide, which made it possible to determine exact time and duration of the bolide and estimate its brightness. The bolide reached its maximum brightness of at least magnitude -18 in one huge flare. Later on, several surveillance camera data were published showing the moment when the night turned into day for a second, but only two videos from Hungary (Orkeny village, Fazzi Daniella and Vass Gabor; Telki village, contact persons Sarneczky Krisztian, and Kiss Laszlo) actually captured the fireball itself. Thanks to calibration of videos by several members of the Hungarian Astronomical Association (MCSE, http://www.mcse.hu) contributing (in particular, Antal Igaz) and a trajectory analysis by Dr. Jiri Borovicka of the Czech Academy of Sciences gave the hope that significant numbers of meteorite fragments reached the surface. He also calculated the impact area, near the town of Kosice in eastern Slovakia. The data from the Local Seismic Network of Eastern Slovakia (project led by Professor Moczo of Comenius University) confirmed the atmospheric trajectory as well. The expedition consisting of scientists and graduate students of the Astronomical Institute of the Slovak Academy of

  15. Allan Deviation Plot as a Tool for Quartz-Enhanced Photoacoustic Sensors Noise Analysis.

    PubMed

    Giglio, Marilena; Patimisco, Pietro; Sampaolo, Angelo; Scamarcio, Gaetano; Tittel, Frank K; Spagnolo, Vincenzo

    2016-04-01

    We report here on the use of the Allan deviation plot to analyze the long-term stability of a quartz-enhanced photoacoustic (QEPAS) gas sensor. The Allan plot provides information about the optimum averaging time for the QEPAS signal and allows the prediction of its ultimate detection limit. The Allan deviation can also be used to determine the main sources of noise coming from the individual components of the sensor. Quartz tuning fork thermal noise dominates for integration times up to 275 s, whereas at longer averaging times, the main contribution to the sensor noise originates from laser power instabilities.

  16. Oxygen Isotopes in Meteorites

    NASA Astrophysics Data System (ADS)

    Clayton, R. N.

    2003-12-01

    Oxygen isotope abundance variations in meteorites are very useful in elucidating chemical and physical processes that occurred during the formation of the solar system (Clayton, 1993). On Earth, the mean abundances of the three stable isotopes are 16O: 99.76%, 17O: 0.039%, and 18O: 0.202%. It is conventional to express variations in abundances of the isotopes in terms of isotopic ratios, relative to an arbitrary standard, called SMOW (for standard mean ocean water), as follows:The isotopic composition of any sample can then be represented by one point on a "three-isotope plot," a graph of δ17O versus δ18O. It will be seen that such plots are invaluable in interpreting meteoritic data. Figure 1 shows schematically the effect of various processes on an initial composition at the center of the diagram. Almost all terrestrial materials lie along a "fractionation" trend; most meteoritic materials lie near a line of "16O addition" (or subtraction). (4K)Figure 1. Schematic representation of various isotopic processes shown on an oxygen three-isotope plot. Almost all terrestrial materials plot along a line of "fractionation"; most primitive meteoritic materials plot near a line of "16O addition." The three isotopes of oxygen are produced by nucleosynthesis in stars, but by different nuclear processes in different stellar environments. The principal isotope, 16O, is a primary isotope (capable of being produced from hydrogen and helium alone), formed in massive stars (>10 solar masses), and ejected by supernova explosions. The two rare isotopes are secondary nuclei (produced in stars from nuclei formed in an earlier generation of stars), with 17O coming primarily from low- and intermediate-mass stars (<8 solar masses), and 18O coming primarily from high-mass stars (Prantzos et al., 1996). These differences in type of stellar source result in large observable variations in stellar isotopic abundances as functions of age, size, metallicity, and galactic location ( Prantzos

  17. The 45th Annual Meteoritical Society Meeting

    NASA Technical Reports Server (NTRS)

    Jones, P. (Compiler); Turner, L. (Compiler)

    1982-01-01

    Impact craters and shock effects, chondrite formation and evolution, meteorites, chondrules, irons, nebular processes and meteorite parent bodies, regoliths and breccias, antarctic meteorite curation, isotopic studies of meteorites and lunar samples, organics and terrestrial weathering, refractory inclusions, cosmic dust, particle irradiations before and after compaction, and mineralogic studies and analytical techniques are discussed.

  18. Seizures in the life and works of Edgar Allan Poe.

    PubMed

    Bazil, C W

    1999-06-01

    Edgar Allan Poe, one of the most celebrated of American storytellers, lived through and wrote descriptions of episodic unconsciousness, confusion, and paranoia. These symptoms have been attributed to alcohol or drug abuse but also could represent complex partial seizures, prolonged postictal states, or postictal psychosis. Complex partial seizures were not well described in Poe's time, which could explain a misdiagnosis. Alternatively, he may have suffered from complex partial epilepsy that was complicated or caused by substance abuse. Even today, persons who have epilepsy are mistaken for substance abusers and occasionally are arrested during postictal confusional states. Poe was able to use creative genius and experiences from illness to create memorable tales and poignant poems.

  19. The dynamic Allan variance II: a fast computational algorithm.

    PubMed

    Galleani, Lorenzo

    2010-01-01

    The stability of an atomic clock can change with time due to several factors, such as temperature, humidity, radiations, aging, and sudden breakdowns. The dynamic Allan variance, or DAVAR, is a representation of the time-varying stability of an atomic clock, and it can be used to monitor the clock behavior. Unfortunately, the computational time of the DAVAR grows very quickly with the length of the analyzed time series. In this article, we present a fast algorithm for the computation of the DAVAR, and we also extend it to the case of missing data. Numerical simulations show that the fast algorithm dramatically reduces the computational time. The fast algorithm is useful when the analyzed time series is long, or when many clocks must be monitored, or when the computational power is low, as happens onboard satellites and space probes.

  20. Antarctic Meteorite Newsletter. Volume 22

    NASA Technical Reports Server (NTRS)

    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.

  1. Impact Crater Particulates: Microscopic Meteoritic Material Surrounding Meteorite Craters

    NASA Astrophysics Data System (ADS)

    Smith, Toby Russell

    1995-01-01

    The influx of extraterrestrial matter onto the Earth is a ongoing process. Every year 40,000 metric tons of extraterrestrial matter is accreted by the Earth (Love 1993). A small fraction of this material arrives at Earth as objects large enough to survive the passage through atmosphere. Some of this material is completely melted as it passes through the atmosphere and arrives at the surface of the Earth as cosmic spherules. Cosmic spherules formed from metallic cosmic material undergoes changes in its elemental abundance as it passes through the atmosphere. The oxidation of the spherules results in the concentration of more refractory elements like Ni and Co into the metallic phase. Cosmic spherules are also formed by the passage of large meteorites through the atmosphere and their resulting impact onto the Earth. I found that the cosmic spherules from a wide variety of sources show a very similar trend in the elemental abundance patterns of their metallic phases. This trend is most obvious in the spherules recovered from the deep -sea and the spherules imbedded in impactite glass recovered from iron meteorite impact crater sites. The metallic spherules recovered from the soil surrounding impact craters do not show the high degree of elemental fractionation found in the deep-sea and impactite spherules. The composition of these spherules indicate that they are a mixture of meteoritic and target material. Metallic spherules are not the only meteoritic material to be found in the soil surrounding meteorite craters. I found that small fragments of the parent meteorite are an ubiquitous component of the soil surrounding the Odessa and Dalgaranga meteorite craters. These fragments occurred as small (most less than 400 mu m in size) heavily weathered fragments of meteoritic metal. The total calculated mass of these fragments is an order of magnitude larger than the mass of ponderable meteorites recovered from the site but 1 to 2 orders of magnitude smaller than the

  2. Organic compounds in meteorites

    NASA Technical Reports Server (NTRS)

    Lawless, J. G.

    1980-01-01

    Recent studies of carbonaceous chondrites provide evidence that certain organic compounds are indigenous and the result of an abiotic, chemical synthesis. The results of several investigators have established the presence of amino acids and precursors, mono- and dicarboxylic acids, N-heterocycles, and hydrocarbons as well as other compounds. For example, studies of the Murchison and Murray meteorites have revealed the presence of at least 40 amino acids with nearly equal abundances of D and L isomers. The population consists of both protein and nonprotein amino acids including a wide variety of linear, cyclic, and polyfunctional types. Results show a trend of decreasing concentration with increasing carbon number, with the most abundant being glycine (41 n Moles/g). These and other results to be reviewed provide persuasive support for the theory of chemical evolution and provide the only natural evidence for the protobiological subset of molecules from which life on earth may have arisen.

  3. An Adulterated Martian Meteorite

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    1999-07-01

    Martian meteorite, Elephant Moraine EETA79001, is composed of two distinct rock types. Scientists have thought that both formed from magmas, hence are igneous rocks and contain important information about the interior of Mars, the nature of lava flows on its surface, and the timing of igneous events on Mars. All that is now open to question, as a group of investigators at Lockheed Martin Space Operations and the Johnson Space Center led by David Mittlefehldt (Lockheed) has shown that one of the rock types making up EETA79001, designated lithology A, is almost certainly a melted mixture of other rocks. Mittlefehldt and coworkers suggest that formation by impact melting is the most likely explanation for the chemical and mineralogical features seen in the rock. If confirmed by other investigations, this may change the way we view the igneous evolution of Mars.

  4. Allan-Herndon-Dudley syndrome with unusual profound sensorineural hearing loss.

    PubMed

    Gagliardi, Lucia; Nataren, Nathalie; Feng, Jinghua; Schreiber, Andreas W; Hahn, Christopher N; Conwell, Louise S; Coman, David; Scott, Hamish S

    2015-08-01

    The Allan-Herndon-Dudley syndrome is caused by mutations in the thyroid hormone transporter, Monocarboxylate transporter 8 (MCT8). It is characterized by profound intellectual disability and abnormal thyroid function. We report on a patient with Allan-Herndon-Dudley syndrome (AHDS) with profound sensorineural hearing loss which is not usually a feature of AHDS and which may have been due to a coexisting nonsense mutation in Microphthalmia-associated transcription factor (MITF).

  5. Meteorite concentration mechanisms in Antarctica

    NASA Technical Reports Server (NTRS)

    Annexstad, J. O.

    1986-01-01

    The location of most Antarctic meteorite finds is on stagnant, highly ablative surfaces known as blue ice. The role of blue ice as transporter, concentrator, and preserver of specimens from the time of fall until find is discussed.

  6. Interstellar organic matter in meteorites

    NASA Technical Reports Server (NTRS)

    Yang, J.; Epstein, S.

    1983-01-01

    Deuterium-enriched hydrogen is present in organic matter in such meteorites as noncarbonaceous chondrites. The majority of the unequilibrated primitive meteorites contain hydrogen whose D/H ratios are greater than 0.0003, requiring enrichment (relative to cosmic hydrogen) by isotope exchange reactions taking place below 150 K. The D/H values presented are the lower limits for the organic compounds derived from interstellar molecules, since all processes subsequent to their formation, including terrestrial contamination, decrease their D/H ratios. In contrast, the D/H ratios of hydrogen associated with hydrated silicates are relatively uniform for the meteorites analyzed. The C-13/C-12 ratios of organic matter, irrespective of D/H ratio, lie well within those observed for the earth. Present findings suggest that other interstellar material, in addition to organic matter, is preserved and is present in high D/H ratio meteorites.

  7. On the application of Allan variance method for Ring Laser Gyro performance characterization

    SciTech Connect

    Ng, L.C.

    1993-10-15

    This report describes the method of Allan variance and its application to the characterization of a Ring Laser Gyro`s (RLG) performance. Allan variance, a time domain analysis technique, is an accepted IEEE standard for gyro specifications. The method was initially developed by David Allan of the National Bureau of Standards to quantify the error statistics of a Cesium beam frequency standard employed as the US Frequency Standards in 1960`s. The method can, in general, be applied to analyze the error characteristics of any precision measurement instrument. The key attribute of the method is that it allows for a finer, easier characterization and identification of error sources and their contribution to the overall noise statistics. This report presents an overview of the method, explains the relationship between Allan variance and power spectral density distribution of underlying noise sources, describes the batch and recursive implementation approaches, validates the Allan variance computation with a simulation model, and illustrates the Allan variance method using data collected from several Honeywell LIMU units.

  8. James Smithson (1765-1829): Smithsonian Institution Founder And Its First Meteorite Investigator

    NASA Astrophysics Data System (ADS)

    Clarke, R. S., Jr.; Ewing, H. P.

    2005-12-01

    The Englishman James Smithson's bequest led to the founding of the Smithsonian Institution in Washington in 1846. He had never visited the US and his motivations are unclear. His archive and meteorite-containing mineral collection were also donated but were tragically lost in the Smithsonian fire in 1865. Only a tantalizing quotation remains: "the cabinet also contained a valuable suite of meteoritic stones, which appear to be . . . the important meteorites which have fallen in Europe during several centuries." Smithson's life spanned late 18th century Enlightenment skepticism concerning meteorites to their acceptance in the early decades of the 19th century. New research reveals Smithson as an active participant at the birth of modern meteoritics. Smithson was well educated, well connected, financially independent, and one of the youngest men ever to be elected a FRS. He spent much of his life in Europe associating with the scientific leaders there, and he was a sought after chemical analyst. William Thomson (1761-1806), an Oxford mentor and a lifelong friend, took up residence in Naples in 1790. He was monitoring Mt. Vesuvius's, an interest shared with Smithson, when it erupted on June 15, 1794. The next day the Siena meteorite fell 200 km to the north. Smithson, then residing in Florence, went immediately over the Chianti Hills to investigate the fall. Welcomed with awed respect by the local savants, the twenty nine year old Smithson investigated the fall and described it in a letter to his mentor Henry Cavendish (1731-1810) for dissemination in London. William Thomson provided a mineralogical description of the Siena stones for the published description. The Siena meteorite fall marked the beginning of a decade of investigation by scientists that led to the acceptance of meteorites. Smithson was there throughout these investigations and the political and social unrest that accompanied them.

  9. 'Scarecrow' Descends Hill

    NASA Technical Reports Server (NTRS)

    2007-01-01

    An engineering model for NASA's Mars Science Laboratory makes its way up a hill in the Mars Yard testing area at NASA's Jet Propulsion Laboratory. The model, called 'Scarecrow' because it does not include a computer brain, is used for tests of mobility and landing.

    The Mars Science Laboratory rover is in development for launch in 2009. JPL, a division of the California Institute of Technology, Pasadena, manages the mission for the NASA Science Mission Directorate, Washington.

  10. Nose Hill Artifacts

    ERIC Educational Resources Information Center

    Hansen, Vivian

    2008-01-01

    A Blackfoot woman, caught in the act of adultery, was condemned at this site to have her nose cut off as a penalty for her actions. People do not know her story. The tribe cast it on the ground. And so She, Nose Hill, was named. John Laurie Boulevard holds her mound in a circlet of asphalt, defining the map of her "terra incognita." She is a park…

  11. Radial forcing and Edgar Allan Poe's lengthening pendulum

    NASA Astrophysics Data System (ADS)

    McMillan, Matthew; Blasing, David; Whitney, Heather M.

    2013-09-01

    Inspired by Edgar Allan Poe's The Pit and the Pendulum, we investigate a radially driven, lengthening pendulum. We first show that increasing the length of an undriven pendulum at a uniform rate does not amplify the oscillations in a manner consistent with the behavior of the scythe in Poe's story. We discuss parametric amplification and the transfer of energy (through the parameter of the pendulum's length) to the oscillating part of the system. In this manner, radial driving can easily and intuitively be understood, and the fundamental concept applied in many other areas. We propose and show by a numerical model that appropriately timed radial forcing can increase the oscillation amplitude in a manner consistent with Poe's story. Our analysis contributes a computational exploration of the complex harmonic motion that can result from radially driving a pendulum and sheds light on a mechanism by which oscillations can be amplified parametrically. These insights should prove especially valuable in the undergraduate physics classroom, where investigations into pendulums and oscillations are commonplace.

  12. Antarctic Meteorite Classification and Petrographic Database

    NASA Technical Reports Server (NTRS)

    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

  13. The Meteoritical Bulletin, no. 85, 2001 September

    USGS Publications Warehouse

    Grossman, J.N.; Zipfel, J.

    2001-01-01

    Meteoritical Bulletin No. 85 lists information for 1376 newly classified meteorites, comprising 658 from Antarctica, 409 from Africa, 265 from Asia (262 of which are from Oman), 31 from North America, 7 from South America, 3 from Australia, and 3 from Europe. Information is provided for 11 falls (Dergaon, Dunbogan, Gujba, Independence, Itqiy, Mora??vka, Oued el Hadjar, Sayama, Sologne, Valera, and Worden). Noteworthy non-Antarctic specimens include 5 martian meteorites (Dar al Gani 876, Northwest Africa 480 and 817, and Sayh al Uhaymir 051 and 094); 6 lunar meteorites (Dhofar 081, 280, and 287, and Northwest Africa 479, 482, and 773); an ungrouped enstatite-rich meteorite (Itqiy); a Bencubbin-like meteorite (Gujba); 9 iron meteorites; and a wide variety of other interesting stony meteorites, including CH, CK, CM, CO, CR, CV, R, enstatite, and unequilibrated ordinary chondrites, primitive achondrites, HED achondrites, and ureilites.

  14. How do the Properties of Allan Hills 84001 Compare With Accepted Criteria for Evidence of Ancient Life?

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; McKay, D. S.; Thomas-Keprta, K.; Westall, F.; Romanek, C. A.

    1998-01-01

    Criteria for Past Life: To be confident that any sample contains evidence of past life or biogenic activity, one must determine beyond a shadow of a doubt that certain well-established features or biomarker signatures are present in the sample. In the case of martian samples, the criteria for past life have not been established because if life existed on the planet, we have no way of knowing its detailed characteristics. Lacking independent evidence about the nature of possible past life on Mars, the scientific community must use, for the time being, the criteria established for ancient samples from the Earth: (1) Do we know the geologic context of the sample? Is it compatible with past life? (2) Do we know the age of the sample and its stratigraphic location? Are they understood enough to relate possible life to geologic history? (3) Does the sample contain evidence of cellular morphology? (4) What structural remains of colonies or communities exist within the samples? (5) Is there any evidence of biominerals showing chemical or mineral disequilibria? (6) Is there any evidence of stable isotope patterns unique to biology? (7) Are there any organic biomarkers present? (8) Are the features indigenous to the sample? For acceptance of past life in a geologic sample, essentially all of these criteria must he met.

  15. Online estimation of Allan variance coefficients based on a neural-extended Kalman filter.

    PubMed

    Miao, Zhiyong; Shen, Feng; Xu, Dingjie; He, Kunpeng; Tian, Chunmiao

    2015-01-01

    As a noise analysis method for inertial sensors, the traditional Allan variance method requires the storage of a large amount of data and manual analysis for an Allan variance graph. Although the existing online estimation methods avoid the storage of data and the painful procedure of drawing slope lines for estimation, they require complex transformations and even cause errors during the modeling of dynamic Allan variance. To solve these problems, first, a new state-space model that directly models the stochastic errors to obtain a nonlinear state-space model was established for inertial sensors. Then, a neural-extended Kalman filter algorithm was used to estimate the Allan variance coefficients. The real noises of an ADIS16405 IMU and fiber optic gyro-sensors were analyzed by the proposed method and traditional methods. The experimental results show that the proposed method is more suitable to estimate the Allan variance coefficients than the traditional methods. Moreover, the proposed method effectively avoids the storage of data and can be easily implemented using an online processor. PMID:25625903

  16. A Capitol Hill Perspective

    NASA Astrophysics Data System (ADS)

    Sheppard, Christal

    2006-04-01

    Relatively few women receive advanced degrees in the sciences, and relatively few scientists find their way into staff positions on Capitol Hill. Yet in this staffer's experience, I count more female science Ph.D.s in my circle of colleagues than I counted female classmates in physics graduate school. Why, at least anecdotally, does it seem that women with advanced degrees in science are more likely than their male peers to leave the laboratory and join the policy lobby? My observations are based on my own work in energy and environmental policy as a staffer in both the U.S. Senate and the U.S. House of Representatives.

  17. KISATCHIE HILLS WILDERNESS, LOUISIANA.

    USGS Publications Warehouse

    Haley, Boyd R.; Ryan, George S.

    1984-01-01

    A mineral-resource survey of the Kisatchie Hills Wilderness, Louisiana indicated little promise for the occurrence of mineral resources. There is insufficient data on oil and gas producing formations that underlie the area to evaluate the oil and gas resource potential. All the oil fields of Wilcox age are less than 40 acres in extent; therefore, closer spaced deeper wells might find additional fields in sediments of Wilcox age. Oil and natural gas have been produced from older reservoirs (Cretaceous age) to the northwest of the wilderness, and deeper wells might find oil and natural gas in sediments of Cretaceous and older age in the vicinity of the wilderness.

  18. Organic Chemistry of Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    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.

  19. Fossil Meteorite Unearthed From Crater

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.

    2006-06-01

    A team of scientists lead by Wolf Maier (University of Quebec, Canada and University of Pretoria, South Africa and soon at University of Western Australia, Perth) and Marco Andreoli (University of the Witwatersrand and South African Nuclear Energy Corp.) and colleagues who also hail from Canada, South Africa, the United Kingdom, and the United States, have announced the discovery of a 25-centimeter-wide chondritic meteorite unearthed from the 145-million-year-old Morokweng impact crater in South Africa. Found within the crater's impact melt sheet about 770 meters (half a mile) down a drilling borehole, the hefty meteorite's existence would seem improbable given its low chance of surviving the high shock pressures and temperatures normally associated with large impact events. Its unusual composition could mean it is a sample from a previously unknown part of the LL chondrite parent body or maybe it is from an entirely different asteroid population than other known meteorites.

  20. The Magnetization of Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Herndon, James Herndon

    1974-01-01

    Alternating field demagnetization experiments have been conducted on representative samples of the carbonaceous meteorites (carbonaceous chondrites and ureilites). The results indicate that many, if not all, of these meteorites possess an intense and stable magnetic moment of extraterrestrial origin. Thermomagnetic analyses have been conducted on samples of all known carbonaceous meteorites. In addition to yielding quantitative magnetite estimates, these studies indicate the presence of a thermally unstable component, troilite, which reacts with gaseous oxygen to form magnetite. It is proposed that the magnetite found in some carbonaceous chondrites resulted from the oxidation of troilite during the early history of the solar system. The formation of pyrrhotite is expected as a natural consequence of magnetite formation via this reaction. Consideration is given to the implications of magnetite formation on paleointensity studies.

  1. The Meteoritical Bulletin, No. 88, 2004 July

    USGS Publications Warehouse

    Russell, S.S.; Folco, L.; Grady, M.M.; Zolensky, M.E.; Jones, R.; Righter, K.; Zipfel, J.; Grossman, J.N.

    2004-01-01

    The Meteoritical Bulletin No. 88 lists information for 1610 newly classified meteorites, comprising 753 from Antarctica, 302 from Africa, 505 from Asia (495 of which are from Oman), 40 from North America, 5 from South America, 4 from Europe, and 1 of unknown origin. Information is provided for 9 falls (Alby sur Che??ran, Al Zarnkh, Devgaon, Kamioka, Kendrapara, Maromandia, New Orleans, Sivas, and Villalbeto de la Pen??a). Noteworthy specimens include a eucrite fall (Alby sur Che??ran), 6 martian meteorites, 13 lunar meteorites, and 12 irons including one weighing 3 metric ions (Dronino). ?? Meteoritical Society, 2004.

  2. HYDROGEN CYANIDE IN THE MURCHISON METEORITE

    SciTech Connect

    Pizzarello, Sandra

    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.

  3. Mysterious iodine-overabundance in Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    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.

  4. Application of Allan Deviation to Assessing Uncertainties of Continuous-measurement Instruments, and Optimizing Calibration Schemes

    NASA Astrophysics Data System (ADS)

    Jacobson, Gloria; Rella, Chris; Farinas, Alejandro

    2014-05-01

    Technological advancement of instrumentation in atmospheric and other geoscience disciplines over the past decade has lead to a shift from discrete sample analysis to continuous, in-situ monitoring. Standard error analysis used for discrete measurements is not sufficient to assess and compare the error contribution of noise and drift from continuous-measurement instruments, and a different statistical analysis approach should be applied. The Allan standard deviation analysis technique developed for atomic clock stability assessment by David W. Allan [1] can be effectively and gainfully applied to continuous measurement instruments. As an example, P. Werle et al has applied these techniques to look at signal averaging for atmospheric monitoring by Tunable Diode-Laser Absorption Spectroscopy (TDLAS) [2]. This presentation will build on, and translate prior foundational publications to provide contextual definitions and guidelines for the practical application of this analysis technique to continuous scientific measurements. The specific example of a Picarro G2401 Cavity Ringdown Spectroscopy (CRDS) analyzer used for continuous, atmospheric monitoring of CO2, CH4 and CO will be used to define the basics features the Allan deviation, assess factors affecting the analysis, and explore the time-series to Allan deviation plot translation for different types of instrument noise (white noise, linear drift, and interpolated data). In addition, the useful application of using an Allan deviation to optimize and predict the performance of different calibration schemes will be presented. Even though this presentation will use the specific example of the Picarro G2401 CRDS Analyzer for atmospheric monitoring, the objective is to present the information such that it can be successfully applied to other instrument sets and disciplines. [1] D.W. Allan, "Statistics of Atomic Frequency Standards," Proc, IEEE, vol. 54, pp 221-230, Feb 1966 [2] P. Werle, R. Miicke, F. Slemr, "The Limits

  5. Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, Grorge

    2001-01-01

    Carbonaceous meteorites are relatively enriched in soluble organic compounds. To date, these compounds provide the only record available to study a range of organic chemical processes in the early Solar System chemistry. The Murchison meteorite is the best-characterized carbonaceous meteorite with respect to organic chemistry. The study of its organic compounds has related principally to aqueous meteorite parent body chemistry and compounds of potential importance for the origin of life. Among the classes of organic compounds found in Murchison are amino acids, amides, carboxylic acids, hydroxy acids, sulfonic acids, phosphonic acids, purines and pyrimidines (Table 1). Compounds such as these were quite likely delivered to the early Earth in asteroids and comets. Until now, polyhydroxylated compounds (polyols), including sugars (polyhydroxy aldehydes or ketones), sugar alcohols, sugar acids, etc., had not been identified in Murchison. Ribose and deoxyribose, five-carbon sugars, are central to the role of contemporary nucleic acids, DNA and RNA. Glycerol, a three-carbon sugar alcohol, is a constituent of all known biological membranes. Due to the relative lability of sugars, some researchers have questioned the lifetime of sugars under the presumed conditions on the early Earth and postulated other (more stable) compounds as constituents of the first replicating molecules. The identification of potential sources and/or formation mechanisms of pre-biotic polyols would add to the understanding of what organic compounds were available, and for what length of time, on the ancient Earth.

  6. Extraterrestrial Organic Compounds in Meteorites

    NASA Technical Reports Server (NTRS)

    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.

  7. Indigenous microfossils in carbonaceous meteorites

    NASA Astrophysics Data System (ADS)

    Hoover, Richard B.; Jerman, Gregory; Rozanov, Alexei Y.; Sipiera, Paul P.

    2004-11-01

    Indigenous embedded microbial filaments, bacterial cells and other microfossils were found in the Orgueil, Ivuna (CI1), Murchison, and Bells (CM2) carbonaceous meteorites. Biominerals, biofilms, framboids, magnetite platelets, and curious elemental iron ovoids covered with minute fibrils and carbon sheaths were also found. The S-4100 Hitachi Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray Analysis (EDAX) were used for in situ investigations of freshly fractured interior meteorite surfaces. EDAX x-ray spectra shows the microfossils bear signatures of the meteorite matrix and possess elemental ratios indicating they are indigenous and not recent microbial contaminants. Many of the well-preserved biogenic remains in the meteorites are encased within carbon-rich, sometimes electron transparent, sheaths. Their size, morphology and ultra microstructure are comparable to microfossils known from the phosphorites of Khubsughul, Mongolia and to some of the living cyanobacteria and other sulfur- and sulfate-reducing bacteria known from the halophilic Microcoleus mats of Sivash Lagoon, Crimea and from Mono Lake in California.

  8. Analysis of the Farmville Meteorite

    NASA Astrophysics Data System (ADS)

    Ferm, Megan

    2011-10-01

    Meteoroids are objects that are constantly bombarded by cosmic rays in outer space. Through spallation reactions between cosmic rays and meteoroid matter, radioactive nuclides, such as 26Al, are produced. 26Al is a positron emitter, meaning that the positron annihilates within a cubic millimeter of the sample. This results in the release of two 511 keV photons, in addition to an 1809 keV gamma ray from the decay to the 26Mg ground state. This study focuses on the detection of 26Al in the Farmville meteorite, which fell in North Carolina in 1934. The meteorite has been centered in our sensitive apparatus, and the conditions for detection require a triple gamma coincidence which greatly reduced background. With the radioisotopes measured within the sample, Monte Carlo transport simulations (using the package Geant4) will be performed to determine the amount of 26Al in the meteorite. With this information, it may be possible to determine the time the meteorite entered Earth's atmosphere (which should be consistent with the reported find time), the time period that the meteoroid was exposed to the cosmic rays, the pre-atmospheric size of the meteoroid and the intensity of cosmic rays in the inner solar system.

  9. Lunar sample analysis. [Allende meteorite

    NASA Technical Reports Server (NTRS)

    Housley, R. M.

    1985-01-01

    Recent results on the antarctic meteorite ALPHA 77003 which contribute to understanding the alteration processes which produced matrix in unequilibrated chondrites are presented. Also included are additional scanning electron microscope results confirming that the matrix in Allende was formed by in situ alteration.

  10. Antarctic Meteorite Classification and Petrographic Database Enhancements

    NASA Technical Reports Server (NTRS)

    Todd, N. S.; Satterwhite, C. E.; Righter, K.

    2012-01-01

    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. This paper describes enhancements that have been made to the database and to the data and photo acquisition process to provide the meteorite community with faster access to meteorite data concurrent with the publication of the Antarctic Meteorite Newsletter twice a year.

  11. Recent meteorite falls in South Korea

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Kim, M.; Byun, Y.; Yi, H.; Chang, S.; Choi, J.; Sohn, J.; Moon, H.; Park, J.

    2014-07-01

    In the evening of March 9, 2014, a fireball falling from north to south was observed in South Korea. Multiple explosions were heard and multiple videos recorded in cars from various places, suggesting that the fireball was separated into several pieces. Immediately thereafter, a series of discovery reports about meteorites from the southern part of South Korea followed and, as of today, three meteorites were confirmed and one meteorite, with a mass of about 20 kg, is pending. This discovery of a meteorite in South Korea occurs for the first time in 70 years. The overall trajectory of the fireball matches the area where meteorites were discovered. According to the preliminary analyses, the meteorite is an ordinary chondrite. The origin of the meteorite and its surface properties will be studied.

  12. The Meteoritical Bulletin, No. 100, 2014 June

    NASA Astrophysics Data System (ADS)

    Ruzicka, Alex; Grossman, Jeffrey N.; Garvie, Laurence

    2014-08-01

    Meteoritical Bulletin 100 contains 1943 meteorites including 8 falls (Boumdeid [2011], Huaxi, Košice, Silistra, Sołtmany, Sutter's Mill, Thika, Tissint), with 1575 ordinary chondrites, 139 carbonaceous chondrites, 96 HED achondrites, 25 ureilites, 18 primitive achondrites, 17 iron meteorites, 15 enstatite chondrites, 11 lunar meteorites, 10 mesosiderites, 10 ungrouped achondrites, 8 pallasites, 8 Martian meteorites, 6 Rumuruti chondrites, 3 enstatite achondrites, and 2 angrites, and with 937 from Antarctica, 592 from Africa, 230 from Asia, 95 from South America, 44 from North America, 36 from Oceania, 6 from Europe, and 1 from an unknown location. This will be the last Bulletin published in the current format. Information about approved meteorites can be obtained from the Meteoritical Bulletin Database (MBD) available online at http://www.lpi.usra.edu/meteor/

  13. Lost Hills, California Interferogram

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This figure shows a comparison of interferograms from four different years mapping the rapid ground subsidence over the Lost Hills oil field in California. Lost Hills is located about 60 km (40 miles) northwest of Bakersfield in the San Joaquin Valley. The oil field is about 1.5 km (1mile) wide and 6 km (3.5 miles) long.

    Each interferogram was created using pairs of images taken by synthetic aperture radar that have been combined to measure surface deformation or changes that may have occurred in the time between when data for the two images were taken. The images were collected by the European Space Agency's Remote Sensing satellites (ERS-1 and ERS-2) in two months of each year shown (1995, 1996, 1998 and 1999) and were combined to produce these image maps of the apparent surface deformation, or changes.

    The interferometric measurements that show the changes, primarily vertical subsidence of the surface, are rendered in color with purple indicating no motion and the brightest red showing rapid subsidence. The white areas are where the radar measurements could not be obtained, mostly in the agricultural fields around the oil fields where plant growth or plowing altered the radar properties of the surface.

    These radar data show that parts of the oil field were subsiding unusually rapidly, more than 3 centimeters (1.2 inches) a month, in 1995 and 1996. They also reveal that while the ground subsidence rate decreased in the center part of the oil field, it increased in the northern part between 1995 and 1996 and 1998 and 1999.

    Subsidence maps like these combined with records of oil and water extraction and injection will help scientist understand how the rocks within an oil field are behaving, leading to improvements in oil field operations.

  14. Lost Hills, California Interferogram

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This figure shows a comparison of interferograms from four different years mapping the rapid ground subsidence over the Lost Hills oil field in California. Lost Hills is located about 60 km (40 miles) northwest of Bakersfield in the San Joaquin Valley. The oilfield is about 1.5 km (1 mile) wide and 6 km (3.5 miles) long. Each interferogram was created using pairs of images taken by synthetic aperture radar that have been combined to measure surface deformation or changes that may have occurred in the time between when data for the two images were taken. The images were collected by the European Space Agency's Remote Sensing satellites (ERS-1 and ERS-2) in two months of each year shown (1995, 1996, 1998 and 1999) and were combined to produce these image maps of the apparent surface deformation, or changes. The interferometric measurements that show the changes, primarily vertical subsidence of the surface, are rendered in color with purple indicating no motion and the brightest red showing rapid subsidence. The white areas are where the radar measurements could not be obtained, mostly in the agricultural fields around the oilfields where plant growth or plowing altered the radar properties of the surface. These radar data show that parts of the oilfield were subsiding unusually rapidly, more than 3 centimenters (1.2 inches) a month, in 1995 and 1996. They also reveal that while the ground subsidence rate decreased in the center part of the oilfield, it increased in the northern part between 1995 and 1996 and 1998 and 1999. Subsidence maps like these combined with records of oil and water extraction and injection will help scientist understand how the rocks within an oilfield are behaving, leading to improvements in oilfield operations. For more information, read Radar Helps Monitor Oil Fields. Images courtesy Eric Fielding, NASA Jet Propulsion Laboratory

  15. 16. Interior view of Cherry Hill lettuce shed looking up ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Interior view of Cherry Hill lettuce shed looking up at the trusses of the second floor - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  16. 6. Oblique view of Cherry Hill lettuce shed looking northeast, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Oblique view of Cherry Hill lettuce shed looking northeast, with chute building to the right - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  17. 22. View of second floor of the Cherry Hill lettuce ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. View of second floor of the Cherry Hill lettuce shed looking at double doors - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  18. 21. View of second floor of the Cherry Hill lettuce ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. View of second floor of the Cherry Hill lettuce shed looking towards window - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  19. 18. View of the second floor of the Cherry Hill ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. View of the second floor of the Cherry Hill lettuce shed looking at door - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  20. 9. View of Cherry Hill lettuce shed looking north, with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. View of Cherry Hill lettuce shed looking north, with chute building on the left - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  1. 3. View of Cherry Hill lettuce shed looking southeast; parking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of Cherry Hill lettuce shed looking southeast; parking lot in foreground - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  2. 12. Partial view of Cherry Hill lettuce shed looking northwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Partial view of Cherry Hill lettuce shed looking northwest showing office - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  3. 20. View of second floor to the Cherry Hill lettuce ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. View of second floor to the Cherry Hill lettuce shed looking at floor area - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  4. 15. Interior view of Cherry Hill lettuce shed showing posts ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Interior view of Cherry Hill lettuce shed showing posts looking towards the chute building - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  5. 14. Interior view of Cherry Hill lettuce shed looking towards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Interior view of Cherry Hill lettuce shed looking towards chute building - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  6. 19. View of second floor of the Cherry Hill lettuce ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. View of second floor of the Cherry Hill lettuce shed looking at door to stairwell - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  7. 2. Oblique view of Cherry Hill lettuce shed looking south; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Oblique view of Cherry Hill lettuce shed looking south; chute building is in background - Richmond Hill Plantation, Cherry Hill Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  8. A ferroan region of the lunar highlands as recorded in meteorites MAC88104 and MAC88105

    SciTech Connect

    Jolliff, B.L.; Korotev, R.L.; Haskin, L.A. )

    1991-11-01

    MacAlpine Hills 88104 and 88105 (MAC88104/5) are paired meteorites of noritic anorthosite composition from the lunar highlands. MAC88105 is a breccia composed mainly of melt-breccia clasts in a fine-grained, fragmental, and partly glassy matrix. The most abundant melt lithologies are feldspathic and are similar in composition to the bulk meteorite. Other melt lithologies include feldspathic melt rocks, mafic melt breccias, and a rare melt breccia relatively enriched in incompatible trace elements. Subordinate lithic clasts are granulitic breccias and ferroan (relatively low Mg/(Mg + Fe)) igneous lithologies, including troctolitic anorthosite, anorthositic norite, gabbronorite, and anorthosite. Igneous clasts having mafic mineral compositions more magnesian than Fo{sub 55} and En{sub 60} were not observed. Rare fragments of glass spheres and shards as well as glass clasts indicate that the meteorite was derived from an immature regolith. The bulk composition of MAC88105 is characterized by a molar Mg/(Mg + Fe) ratio of 0.62, at the extreme low end of the range for meteorites from the lunar highlands. Its low concentrations of incompatible trace elements and feldspathic bulk composition (29% Al{sub 2}O{sub 3}), suggests that it, like the other lunar meteorites, formed at a site far removed from the areas sampled by the Apollo missions. Similarities in mineral compositions among the different lithologies of the breccia and the distribution of mineral fragments suggest that most components of the meteorite were derived from a crustal section dominated by material with a noritic anorthosite composition and an affinity of the ferroan suite of plutonic rocks.

  9. Allan Bloom, Mike Rose, and Paul Goodman: In Search of a Lost Pedagogical Synthesis.

    ERIC Educational Resources Information Center

    Smith, Jeff

    1993-01-01

    Discusses and compares two recent books on American higher education: "The Closing of the American Mind" by Allan Bloom, and "Lives on the Boundary" by Mike Rose. Develops a view which synthesizes those of Bloom and Rose. Considers this view as comparable to that of Paul Goodman. (HB)

  10. Observation, Inference, and Imagination: Elements of Edgar Allan Poe's Philosophy of Science

    ERIC Educational Resources Information Center

    Gelfert, Axel

    2014-01-01

    Edgar Allan Poe's standing as a literary figure, who drew on (and sometimes dabbled in) the scientific debates of his time, makes him an intriguing character for any exploration of the historical interrelationship between science, literature and philosophy. His sprawling "prose-poem" "Eureka" (1848), in particular, has…

  11. Where Were the Whistleblowers? The Case of Allan McDonald and Roger Boisjoly.

    ERIC Educational Resources Information Center

    Stewart, Lea P.

    Employees who "blow the whistle" on their company because they believe it is engaged in practices that are illegal, immoral, or harmful to the public, often face grave consequences for their actions, including demotion, harassment, forced resignation, or termination. The case of Allan McDonald and Roger Boisjoly, engineers who blew the whistle on…

  12. Horror from the Soul--Gothic Style in Allan Poe's Horror Fictions

    ERIC Educational Resources Information Center

    Sun, Chunyan

    2015-01-01

    Edgar Allan Poe made tremendous contribution to horror fiction. Poe's inheritance of gothic fiction and American literature tradition combined with his living experience forms the background of his horror fictions. He inherited the tradition of the gothic fictions and made innovations on it, so as to penetrate to subconsciousness. Poe's horror…

  13. European Studies as Answer to Allan Bloom's "The Closing of the American Mind."

    ERIC Educational Resources Information Center

    Macdonald, Michael H.

    European studies can provide a solution to several of the issues raised in Allan Bloom's "The Closing of the American Mind." European studies pursue the academic quest for what is truth, what is goodness, and what is beauty. In seeking to answer these questions, the Greeks were among the first to explore many of humanity's problems and their…

  14. Allan deviation computations of a linear frequency synthesizer system using frequency domain techniques

    NASA Technical Reports Server (NTRS)

    Wu, Andy

    1995-01-01

    Allan Deviation computations of linear frequency synthesizer systems have been reported previously using real-time simulations. Even though it takes less time compared with the actual measurement, it is still very time consuming to compute the Allan Deviation for long sample times with the desired confidence level. Also noises, such as flicker phase noise and flicker frequency noise, can not be simulated precisely. The use of frequency domain techniques can overcome these drawbacks. In this paper the system error model of a fictitious linear frequency synthesizer is developed and its performance using a Cesium (Cs) atomic frequency standard (AFS) as a reference is evaluated using frequency domain techniques. For a linear timing system, the power spectral density at the system output can be computed with known system transfer functions and known power spectral densities from the input noise sources. The resulting power spectral density can then be used to compute the Allan Variance at the system output. Sensitivities of the Allan Variance at the system output to each of its independent input noises are obtained, and they are valuable for design trade-off and trouble-shooting.

  15. Allan M. Freedman, LLB: a lawyer’s gift to Canadian chiropractors

    PubMed Central

    Brown, Douglas M.

    2007-01-01

    This paper reviews the leadership role, contributions, accolades, and impact of Professor Allan Freedman through a 30 year history of service to CMCC and the chiropractic profession in Canada. Professor Freedman has served as an educator, philanthropist and also as legal counsel. His influence on chiropractic organizations and chiropractors during this significant period in the profession is discussed. PMID:18060008

  16. The Art of George Morrison and Allan Houser: The Development and Impact of Native Modernism

    ERIC Educational Resources Information Center

    Montiel, Anya

    2005-01-01

    The idea for a retrospective on George Morrison and Allan Houser as one of the inaugural exhibitions at the National Museum of the American Indian (NMAI) came from the NMAI curator of contemporary art, Truman Lowe. An artist and sculptor himself, Lowe knew both artists personally and saw them as mentors and visionaries. Lowe advised an exhibition…

  17. An Interview with Allan Wigfield: A Giant on Research on Expectancy Value, Motivation, and Reading Achievement

    ERIC Educational Resources Information Center

    Bembenutty, Hefer

    2012-01-01

    This article presents an interview with Allan Wigfield, professor and chair of the Department of Human Development and distinguished scholar-teacher at the University of Maryland. He has authored more than 100 peer-reviewed journal articles and book chapters on children's motivation and other topics. He is a fellow of Division 15 (Educational…

  18. Image of the Mundrabilla Meteorite

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This is a macro photograph of an etched surface of the Mundrabilla meteorite, a small piece of the approximately 3.9 billion-year-old meteorite that was first discovered in Western Australia in 1911. Two more giant chunks, together weighing about 17 tons, were found in 1966. Researchers can learn much from this natural crystal growth experiment since it has spent several hundred million years cooling, and would be impossible to emulate in a lab. This single slice, taken from a 6 ton piece recovered in 1966, measures only 2 square inches. The macro photograph shows a metallic iron-nickel alloy phase of kamcite (38% Ni) and taenite (6% Ni) at bottom right, bottom left, and top left. The darker material is an iron sulfide (FeS or troilite) with a parallel precipitates of duabreelite (iron chromium sulfide (FeCr2S4).

  19. Interstellar Precursors of Meteoritic Organics

    NASA Technical Reports Server (NTRS)

    Charnley, S. B.

    2003-01-01

    The organic inventory initially available to protostellar disks is the first step on the long chemical path to the development of Life. The early earth may have obtained most its volatile material from the arrival of meteorites and comets at its surface. Determining the most likely distribution of meteoritic and cometary organic molecules that could seed primitive planets is a major goal since it sets the initial conditions for, at least part of, the phase of prebiotic chemical evolution. Observations and measurements of the chemical composition of primitive Solar System organics, and of dense molecular clouds, should allow the construction of coherent theoretical picture of the development of organic complexity from interstellar biogenic material to the beginning of prebiotic evolution.

  20. Cosmogenic radionuclides in stone meteorites

    NASA Technical Reports Server (NTRS)

    Cressy, P. J., Jr.

    1976-01-01

    This document presents the techniques and compilation of results of cosmogenic Al-26 measurements at Goddard Space Flight Center on 91 samples of 76 stone meteorites. Short-lived radionuclides, including Na-22, Sc-46, Mn-54, and Co-60, were measured in 13 of these meteorites. About one-third of these data has not previously been published. The results are discussed briefly in terms of (1) depletion of Al-26 and natural potassium due to weathering, (2) possible exposure of several chondrites to an unusually high cosmic-ray flux, (3) comparison of Al-26, Na-22, Sc-46, and Mn5-54 in chondrites with the spallation Ne-22/Ne-21 ratio as a shielding indicator, and (4) comparison of (Al-26)-(Ne-22)/Ne-21 data for achondrite classes with the chondrite trend.

  1. Antigravity hills are visual illusions.

    PubMed

    Bressan, Paola; Garlaschelli, Luigi; Barracano, Monica

    2003-09-01

    Antigravity hills, also known as spook hills or magnetic hills, are natural places where cars put into neutral are seen to move uphill on a slightly sloping road, apparently defying the law of gravity. We show that these effects, popularly attributed to gravitational anomalies, are in fact visual illusions. We re-created all the known types of antigravity spots in our laboratory using tabletop models; the number of visible stretches of road, their slant, and the height of the visible horizon were systematically varied in four experiments. We conclude that antigravity-hill effects follow from a misperception of the eye level relative to gravity, caused by the presence of either contextual inclines or a false horizon line.

  2. New Insights in Preservation of Meteorites in Hot Deserts: The Oldest Hot Desert Meteorite Collection.

    NASA Astrophysics Data System (ADS)

    Hutzler, A.; Rochette, P.; Bourlès, D.; Gattacceca, J.; Merchel, S.; Jull, A. J. T.; Valenzuela, M.

    2016-08-01

    Terrestrial ages of a subset of a chilean meteorite collection have been determined with cosmogenic nuclides. We show here that provided the environnement is favorable enough, hot desert meteorites can survive over a million year.

  3. Trapped noble gases in meteorites

    NASA Technical Reports Server (NTRS)

    Swindle, Timothy D.

    1988-01-01

    The trapped noble gases in meteorites come in two main varieties, usually referred to as solar and planetary. The solar noble gases are implanted solar-wind or solar-flare materials, and thus their relative elemental abundances provide a good estimate of those of the sun. The planetary noble gases have relative elemental abundances similar to those in the terrestrial atmosphere, but there are also important distinctions. At least one other elemental pattern (subsolar) and several isotopic patterns have also been identified.

  4. No `nanofossils' in martian meteorite

    NASA Astrophysics Data System (ADS)

    Bradley, J. P.; Harvey, R. P.; McSween, H. Y.; Gibson, Everett; Thomas-Keprta, Kathie; Vali, H.

    1997-12-01

    Elongated, segmented forms found on fracture surfaces within the martian meteorite ALH84001 have been proposed to be martian `nanofossils', even though they appear too small to be fossilized bacteria. We have examined similar forms and find that the majority are (non-biological) lamellar growth steps on pyroxene and carbonate crystals. Their segmented surface microstructures are laboratory artefacts resulting from the deposition of conductive heavy-metal coatings.

  5. Cohenite in meteorites: A proposed origin

    USGS Publications Warehouse

    Brett, R.

    1966-01-01

    Cohenite [(Fe, Ni)3C] is found almost exclusively in meteorites containing from 6 to 8 percent nickel (by weight). On the basis of iron-nickel-carbon phase diagrams at 1 atmosphere and of kinetic data, the occurrence of cohenite within this narrow composition range as a low-pressure metastable phase and the nonoccurrence of cohenite in meteorites outside the range 6 to 8 percent nickel can be explained. Cohenite formed in meteorites containing less than 6 to 8 percent nickel decomposed to metal and graphite during cooling; it cannot form in meteorites containing more than about 8 percent. The presence of cohenite in meteorites cannot be used as an indicator of pressure of formation. However, the absence of cohenite in meteorites containing the assemblage, metal plus graphite, requires low pressures during cooling.

  6. The Meteoritical Bulletin, No. 82, 1998 July

    USGS Publications Warehouse

    Grossman, J.N.

    1998-01-01

    Meteoritical Bulletin No. 82 lists information for 974 new meteorites, including 521 finds from Antarctica, 401 finds from the Sahara, 21 finds from the Nullarbor region of Australia, and 7 falls (Ban Rong Du, Burnwell, Fermo, Jalanash, Juancheng, Monahans (1998), and Silao). Many rare types of meteorites are reported: counting pairing groups as one, these include one CR chondrite, two CK chondrites, two CO chondrites, four CV chondrites, one CH chondrite or Bencubbin-like, six C2 (unclassified) chondrites, two EH chondrites, two EL chondrites, three R chondrites, thirty unequilibrated ordinary chondrites, one ungrouped chondrite, three eucrites, six howardites, one diogenite, eleven ureilites, nine iron meteorites, one mesosiderite, two brachinites, one lodranite, one winonaite, and two lunar meteorites (Dar al Gani 400 and EET 96008). All italicized abbreviations refer to addresses tabulated at the end of this document. ?? Meteoritical Society, 1998.

  7. Chlorine Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Bogard, D.D.; Garrison, D.H.; Park, J.

    2009-01-01

    Chlorine measurements made in martian surface rocks by robotic spacecraft typically give Chlorine (Cl) abundances of approximately 0.1-0.8%. In contrast, Cl abundances in martian meteorites appear lower, although data is limited, and martian nakhlites were also subjected to Cl contamination by Mars surface brines. Chlorine abundances reported by one lab for whole rock (WR) samples of Shergotty, ALH77005, and EET79001 range 108-14 ppm, whereas Cl in nakhlites range 73-1900 ppm. Measurements of Cl in various martian weathering phases of nakhlites varied 0.04-4.7% and reveal significant concentration of Cl by martian brines Martian meteorites contain much lower Chlorine than those measured in martian surface rocks and give further confirmation that Cl in these surface rocks was introduced by brines and weathering. It has been argued that Cl is twice as effective as water in lowering the melting point and promoting melting at shallower martian depths, and that significant Cl in the shergottite source region would negate any need for significant water. However, this conclusion was based on experiments that utilized Cl concentrations more analogous to martian surface rocks than to shergottite meteorites, and may not be applicable to shergottites.

  8. Cosmogenic records in Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Goswami, J. N.; Nishiizumi, K.

    1983-01-01

    Aliquot samples of 29 Antarctic L and H chondrites are analyzed for their nuclear track records and Mn-53 activities. The track density in the analyzed samples ranges from 10 to the 4th to approximately 6 x 10 to the 6th per sq cm. A significant finding is the observation of track-rich grains in a set of four L3 chondrites (ALHA 77215, 77216, 77217, and 77252), suspected of belonging to the same fall based on petrographic observations. An additional sample, ALHA 78105, an L6 chondrite, also has track-rich grains. Mn-53 activity is at near saturation level in approximately 65 percent of the analyzed samples, suggesting exposure ages of greater than 10 m.y. in these cases. Very few H chondrites from the 7-m.y. exposure age peak are apparently sampled among the ones investigated in this study. Approximately 6 percent and 4 percent, respectively, of the Antarctic H and L chondrites analyzed thus far for their cosmogenic records have precompaction irradiation features. A combined analysis of Mn-53 and nuclear track data makes it possible to confirm or rule out the proposed pairing of several sets of Antarctic meteorites and to estimate the preatmospheric sizes of some of these meteorites. The results suggest that most of the small Antarctic meteorites (less than 1 kg) have suffered high (greater than 95 percent) ablation mass-loss.

  9. Electrical conductivity of chondritic meteorites

    NASA Technical Reports Server (NTRS)

    Duba, AL; Didwall, E. M.; Burke, G. J.; Sonett, C. P.

    1987-01-01

    The electrical conductivity of samples of the Murchison and Allende carbonaceous chondrites is 4 to 6 orders of magnitude greater than rock forming minerals such as olivine for temperatures up to 700 C. The remarkably high electrical conductivity of these meteorites is attributed to carbon at the grain boundaries. Much of this carbon is produced by pyrolyzation of hydrocarbons at temperatures in excess of 150 C. As the temperature increases, light hydrocarbons are driven off and a carbon-rich residue or char migrates to the grain boundaries enhancing electrical conductivity. Assuming that carbon was present at the grain boundaries in the material which comprised the meteorite parent bodies, the electrical heating of such bodies was calculated as a function of body size and solar distance during a hypothetical T-Tauri phase of the sun. Input conductivity data for the meteorite parent body were the present carbonaceous chondrite values for temperatures up to 840 C and the electrical conductivity values for olivine above 840 C.

  10. Meteoritic material on the moon

    NASA Technical Reports Server (NTRS)

    Morgan, J. W.; Ganapathy, R.; Higuchi, H.; Anders, E.

    1977-01-01

    Three types of meteoritic material are found on the moon: micrometeorites, ancient planetesimal debris from the "early intense bombardment," and debris of recent, craterforming projectiles. Their amounts and compositions have been determined from trace element studies. The micrometeorite component is uniformly distributed over the entire lunar surface, but is seen most clearly in mare soils. It has a primitive, C1-chondrite-like composition, and comprises 1 to 1.5 percent of mature soils. Apparently it represents cometary debris. The ancient component is seen in highland breccias and soils. Six varieties have been recognized, differing in their proportions of refractories (Ir, Re), volatiles (Ge, Sb), and Au. All have a fractionated composition, with volatiles depleted relative to siderophiles. The abundance patterns do not match those of the known meteorite classes. These ancient meteoritic components seem to represent the debris of an extinct population of bodies (planetisimals, moonlets) that produced the mare basins during the first 700 Myr of the moon's history. On the basis of their stratigraphy and geographic distribution, five of the six groups are tentatively assigned to specific mare basins: Imbrium, Serenitatis, Crisium, Nectaris, and Humorum or Nubium.

  11. Oxygen isotope relationships in iron meteorites

    NASA Technical Reports Server (NTRS)

    Clayton, R. N.; Mayeda, T. K.; Olsen, E. J.; Prinz, M.

    1983-01-01

    Iron meteorites with oxygen-bearing phases can be classified in terms of their oxygen isotopic abundances. These iron meteorite classes are isotopically similar to various stony meteorite classes, which may indicate a common origin. The group IAB and IIICD irons may be related to the winonaites; group IIE irons may be related to H chondrites; group IVA irons may be related to L or LL chondrites.

  12. Cliftonite in meteorites: A proposed origin

    USGS Publications Warehouse

    Brett, R.; Higgins, G.T.

    1967-01-01

    Cliftonite, a polycrystalline aggregate of graphite with cubic morphology, is known in ten meteorites. Some workers have considered it to be a pseudomorph after diamond, and have used the proposed diamond ancestry as evidence of a meteoritic parent body of at least lunar dimensions. We have synthesized cliftonite in Fe-Ni-C alloys in vacuum, as a product of decomposition of cohenite [(Fe,Ni)3C]. We therefore suggest that a high pressure origin is unnecessary for meteorites which contain cliftonite, and that these meteorites were formed at low pressures. This conclusion is in agreement with other recent evidence.

  13. Antarctic Meteorite Newsletter, Volume 8, Number 2

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Requests for samples are welcomed from research scientists of all countries, regardless of their current state of funding for meteorite studies. All sample requests will be reviewed by the Meteorite Working Group (MWG), a peer-review committee that guides the collection, curation, allocation, and distribution of the U.S. Antarctic meteorites. Issurance of samples does not imply a commitment by any agency to fund the proposed research. Requests for financial support must be submitted separately to the appropriate funding agencies. As a matter of policy, U.S. Antarctic meteorites are the property of the National Science Foundation and all allocations are subject to recall.

  14. Soufriere Hills Volcano

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit.

    This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is

  15. Mineralogical investigations of lunar samples and meteorites

    NASA Technical Reports Server (NTRS)

    Marvin, U. B.

    1985-01-01

    Electron microprobe analysis was employed to study north ray crater breccia 67015 from the Moon. The melting history of lunar troctolite 130-9 was investigated, along with the presence of Mg-26 in anorthite grains recovered from the Vaca Meurta mesosiderite. Geographic distributions of meteorites in Antarctica were plotted. The Allende meteorite was analyzed with the electron microprobe method.

  16. Meteoritics and Planetary Science Supplement. Volume 35

    NASA Technical Reports Server (NTRS)

    Sears, Derek W. G. (Editor); Binzel, Richard P. (Editor); Gaffey, Michael J. (Editor); Kraehenbuehl, Urs (Editor); Pieters, Carle M. (Editor); Shaw, Denis (Editor); Wieler, Rainer (Editor); Brownlee, Donald E. (Editor); Goldstein, Joseph I. (Editor); Lyon, Ian C. (Editor)

    2000-01-01

    This special supplement of the Meteoritics and Planetary Science Society Journal contains the abstracts of 324 technical presentations, and the presentations of awards during the Annual meeting of the Meteoritical Society. The abstracts review current research on meteors and planetary sciences.

  17. Martian Alteration in Unique Meteorite NWA 8159?

    NASA Astrophysics Data System (ADS)

    Hallis, L. J.; Simpson, S.; Mark, D.; Lee, M. R.

    2016-08-01

    This study aims to determine if the olivine alteration in martian meteorite NWA 8159 has a martian origin. If so, the unique nature of this meteorite presents evidence for aqueous processes at a new time and location on the martian surface.

  18. Meteoritic basalts. Final report, 1986-1989

    SciTech Connect

    Treiman, A.H.

    1989-10-01

    The objectives were to: explain the abundances of siderophile elements in the SNC meteorite suite, of putative Martian origin; discover the magmatic origins and possibly magma compositions behind the Nakhla meteorite, one of the SNC meteorites; and a re-evaluation of the petrology of Angra dos Reis, a unique meteorite linked to the earliest planetary bodies of the solar nebula. A re-evaluation of its petrography showed that the accepted scenario for its origin, as a cumulate igneous rock, was not consistent with the meteorite's textures (Treiman). More likely is that the meteorite represents a prophyritic igneous rock, originally with magma dominant. Studies of the Nakhla meteorite, of possible Martian origin, although difficult, were successful. It became necessary to reject the basic categorization of Nakhla: that is was a cumulate igneous rock. Detailed studies of the chemical zoning of Nakhlas' minerals, coupled with the failure of experimental studies to yield expected results, forced the conclusion that Nakhla is not a cumulate rock in the usual sense: a rock composed of igneous crystals and intercrystal magma. Study of the siderophile element abundances in the SNC meteorite groups involved trying to find reasonable core formation processes and parameters that would reproduce the observed abundances. Modelling was successful, and delimited a range of models which overlap with those reasonable from geophysical constraints.

  19. The Meteoritical Bulletin, No. 96, September 2009

    USGS Publications Warehouse

    Weisberg, M.K.; Smith, C.; Benedix, G.; Herd, C.D.K.; Righter, K.; Haack, H.; Yamaguchi, A.; Chennaoui, Aoudjehane H.; Grossman, J.N.

    2009-01-01

    The Meteoritical Bulletin No. 96 contains a total of 1590 newly approved meteorite names with their relevant data. These include 12 from specific locations within Africa, 76 from northwest Africa, 9 from the Americas, 13 from Asia, 1 from Australia, 2 from Europe, 950 from Antarctica recovered by the Chinese Antarctic Research Expedition (CHINARE), and 527 from the American Antarctic program (ANSMET). Among these meteorites are 4 falls, Almahata Sitta (Sudan), Sulagiri (India), Ash Creek (United States), and Maribo (Denmark). Almahata Sitta is an anomalous ureilite and is debris from asteroid 2008 TC3 and Maribo is a CM2 chondrite. Other highlights include a lunar meteorite, a CM1 chondrite, and an anomalous IVA iron. ?? The Meteoritical Society, 2009.

  20. Amino acids in the Tagish Lake Meteorite

    NASA Technical Reports Server (NTRS)

    Kminek, G.; Botta, O.; Glavin, D. P.; Bada, J. L.

    2002-01-01

    High-performance liquid chromatography (HPLC) based amino acid analysis of a Tagish Lake meteorite sample recovered 3 months after the meteorite fell to Earth have revealed that the amino acid composition of Tagish Lake is strikingly different from that of the CM and CI carbonaceous chondrites. We found that the Tagish Lake meteorite contains only trace levels of amino acids (total abundance = 880 ppb), which is much lower than the total abundance of amino acids in the CI Orgueil (4100 ppb) and the CM Murchison (16 900 ppb). Because most of the same amino acids found in the Tagish Lake meteorite are also present in the Tagish Lake ice melt water, we conclude that the amino acids detected in the meteorite are terrestrial contamination. We found that the exposure of a sample of Murchison to cold water lead to a substantial reduction over a period of several weeks in the amount of amino acids that are not strongly bound to the meteorite matrix. However, strongly bound amino acids that are extracted by direct HCl hydrolysis are not affected by the leaching process. Thus even if there had been leaching of amino acids from our Tagish Lake meteorite sample during its 3 month residence in Tagish Lake ice and melt water, a Murchison type abundance of endogenous amino acids in the meteorite would have still been readily detectable. The low amino acid content of Tagish Lake indicates that this meteorite originated fiom a different type of parent body than the CM and CI chondrites. The parent body was apparently devoid of the reagents such as aldehyldes/ketones, HCN and ammonia needed for the effective abiotic synthesis of amino acids. Based on reflectance spectral measurements, Tagish Lake has been associated with P- or D-type asteroids. If the Tagish Lake meteorite was indeed derived fiom these types of parent bodies, our understanding of these primitive asteroids needs to be reevaluated with respect to their potential inventory of biologically important organic compounds.

  1. Annual Occurrence of Meteorite-Dropping Fireballs

    NASA Astrophysics Data System (ADS)

    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.

  2. Stardust silicates from primitive meteorites.

    PubMed

    Nagashima, Kazuhide; Krot, Alexander N; Yurimoto, Hisayoshi

    2004-04-29

    Primitive chondritic meteorites contain material (presolar grains), at the level of a few parts per million, that predates the formation of our Solar System. Astronomical observations and the chemical composition of the Sun both suggest that silicates must have been the dominant solids in the protoplanetary disk from which the planets of the Solar System formed, but no presolar silicates have been identified in chondrites. Here we report the in situ discovery of presolar silicate grains 0.1-1 microm in size in the matrices of two primitive carbonaceous chondrites. These grains are highly enriched in 17O (delta17O(SMOW) > 100-400 per thousand ), but have solar silicon isotopic compositions within analytical uncertainties, suggesting an origin in an oxygen-rich red giant or an asymptotic giant branch star. The estimated abundance of these presolar silicates (3-30 parts per million) is higher than reported for other types of presolar grains in meteorites, consistent with their ubiquity in the early Solar System, but is about two orders of magnitude lower than their abundance in anhydrous interplanetary dust particles. This result is best explained by the destruction of silicates during high-temperature processing in the solar nebula.

  3. The Chelyabinsk Fireball and Meteorite.

    NASA Astrophysics Data System (ADS)

    Galimov, E. M.; Kolotov, V. P.; Nazarov, M. A.; Kostitsyn, Yu. A.; Kubrakova, I. V.; Kononkova, N. N.; Alekseev, I. A.; Koshkarov, L. L.; Badyukov, D. D.; Sevastyanov, V. S.; Pillinger, C. T.; Greenwood, R. C.; Verchovsky, A. B.; Johnson, D.; Tindle, A. G.; Buikin, A.

    2013-09-01

    On 15th February 2013 an extraordinarily large fireball detonated in the atmosphere over Chelyabinsk, Russia, with a total energy equivalent to 440 kilotons of TNT. It was the most energetic natural atmospheric occurrence since the Tunguska incident in 1908 and caused many injuries and extensive property damage. Geochemical and isotopic data show that the meteorite samples recovered after the event are LL5 type ordinary chondrites with a S4 shock history. The many thousands of small fragments comprise either of two distinct lithologies: a hondrule-rich light coloured material (~66%) or a less-abundant (~34%) dark shock-melt rather than mixtures. The break-up of the object, i.e. the explosion, appears to have been dictated by the object's pre-entry two component structure, which probably formed during a major collision in the asteroid belt 290 My ago. The Chelyabinsk event demonstrates that effective asteroid-hazard mitigation requires structural knowledge of threatening body similar to that obtained by the Hayabusa spacecraft at asteroid Itokawa. The observations made for Chelyabinsk suggest that the Tunguska bolide may also have been a structurally weakened object. Studies of the samples are still at an early stage. A full petrological description of the meteorite lithologies, geochemical and isotopic analyses, chronological data and fission track information will be available by the time of the conference

  4. Stardust silicates from primitive meteorites.

    PubMed

    Nagashima, Kazuhide; Krot, Alexander N; Yurimoto, Hisayoshi

    2004-04-29

    Primitive chondritic meteorites contain material (presolar grains), at the level of a few parts per million, that predates the formation of our Solar System. Astronomical observations and the chemical composition of the Sun both suggest that silicates must have been the dominant solids in the protoplanetary disk from which the planets of the Solar System formed, but no presolar silicates have been identified in chondrites. Here we report the in situ discovery of presolar silicate grains 0.1-1 microm in size in the matrices of two primitive carbonaceous chondrites. These grains are highly enriched in 17O (delta17O(SMOW) > 100-400 per thousand ), but have solar silicon isotopic compositions within analytical uncertainties, suggesting an origin in an oxygen-rich red giant or an asymptotic giant branch star. The estimated abundance of these presolar silicates (3-30 parts per million) is higher than reported for other types of presolar grains in meteorites, consistent with their ubiquity in the early Solar System, but is about two orders of magnitude lower than their abundance in anhydrous interplanetary dust particles. This result is best explained by the destruction of silicates during high-temperature processing in the solar nebula. PMID:15118720

  5. Measurements of Ultra-Stable Oscillator (USO) Allan Deviations in Space

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna G.; Klipstein, William M.; Wang, Rabi T.; Dunn, Charles E.

    2013-01-01

    Researchers have used data from the GRAIL mission to the Moon to make the first in-flight verification of ultra-stable oscillators (USOs) with Allan deviation below 10 13 for 1-to-100-second averaging times. USOs are flown in space to provide stable timing and/or navigation signals for a variety of different science and programmatic missions. The Gravity Recovery and Interior Laboratory (GRAIL) mission is flying twin spacecraft, each with its own USO and with a Ka-band crosslink used to measure range fluctuations. Data from this crosslink can be combined in such a way as to give the relative time offsets of the two spacecrafts USOs and to calculate the Allan deviation to describe the USOs combined performance while orbiting the Moon. Researchers find the first direct in-space Allan deviations below 10(exp -13) for 1-to-100-second averaging times comparable to pre-launch data, and better than measurements from ground tracking of an X-band carrier coherent with the USO. Fluctuations in Earth s atmosphere limit measurement performance in direct-to-Earth links. Inflight USO performance verification was also performed for GRAIL s parent mission, the Gravity Recovery and Climate Experiment (GRACE), using both Kband and Ka-band crosslinks.

  6. On the Design of Attitude-Heading Reference Systems Using the Allan Variance.

    PubMed

    Hidalgo-Carrió, Javier; Arnold, Sascha; Poulakis, Pantelis

    2016-04-01

    The Allan variance is a method to characterize stochastic random processes. The technique was originally developed to characterize the stability of atomic clocks and has also been successfully applied to the characterization of inertial sensors. Inertial navigation systems (INS) can provide accurate results in a short time, which tend to rapidly degrade in longer time intervals. During the last decade, the performance of inertial sensors has significantly improved, particularly in terms of signal stability, mechanical robustness, and power consumption. The mass and volume of inertial sensors have also been significantly reduced, offering system-level design and accommodation advantages. This paper presents a complete methodology for the characterization and modeling of inertial sensors using the Allan variance, with direct application to navigation systems. Although the concept of sensor fusion is relatively straightforward, accurate characterization and sensor-information filtering is not a trivial task, yet they are essential for good performance. A complete and reproducible methodology utilizing the Allan variance, including all the intermediate steps, is described. An end-to-end (E2E) process for sensor-error characterization and modeling up to the final integration in the sensor-fusion scheme is explained in detail. The strength of this approach is demonstrated with representative tests on novel, high-grade inertial sensors. Experimental navigation results are presented from two distinct robotic applications: a planetary exploration rover prototype and an autonomous underwater vehicle (AUV).

  7. On the Design of Attitude-Heading Reference Systems Using the Allan Variance.

    PubMed

    Hidalgo-Carrió, Javier; Arnold, Sascha; Poulakis, Pantelis

    2016-04-01

    The Allan variance is a method to characterize stochastic random processes. The technique was originally developed to characterize the stability of atomic clocks and has also been successfully applied to the characterization of inertial sensors. Inertial navigation systems (INS) can provide accurate results in a short time, which tend to rapidly degrade in longer time intervals. During the last decade, the performance of inertial sensors has significantly improved, particularly in terms of signal stability, mechanical robustness, and power consumption. The mass and volume of inertial sensors have also been significantly reduced, offering system-level design and accommodation advantages. This paper presents a complete methodology for the characterization and modeling of inertial sensors using the Allan variance, with direct application to navigation systems. Although the concept of sensor fusion is relatively straightforward, accurate characterization and sensor-information filtering is not a trivial task, yet they are essential for good performance. A complete and reproducible methodology utilizing the Allan variance, including all the intermediate steps, is described. An end-to-end (E2E) process for sensor-error characterization and modeling up to the final integration in the sensor-fusion scheme is explained in detail. The strength of this approach is demonstrated with representative tests on novel, high-grade inertial sensors. Experimental navigation results are presented from two distinct robotic applications: a planetary exploration rover prototype and an autonomous underwater vehicle (AUV). PMID:26800535

  8. Stratigraphic Relationships on Husband Hill, Mars

    NASA Astrophysics Data System (ADS)

    Cole, S. B.; Watters, W. A.; Squyres, S. W.

    2011-03-01

    We measure bedding plane orientations of outcrops on Cumberland Ridge in the Columbia Hills. Our measurements are consistent with the hypotheses that the outcrops (1) form a stratigraphic section, and (2) drape the Husband Hill edifice.

  9. Meteorites. Earth Science Curriculum Project Pamphlet Series PS-10.

    ERIC Educational Resources Information Center

    Moore, Carleton B.

    Discussed are meteors from an historical and astronomical viewpoint; then presented is the chemical makeup of iron meteorites, stony meteorites, and stony-iron meteorites. Age determination, moon craters, and tektites are also treated. The interested observer learns how to identify meteorites and to describe how they fall. (Author/RE)

  10. 'Columbia Hills' Color Elevation Map

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: Spirit's Long Journey, Sol 450

    This elevation map shows the region of the 'Columbia Hills' where NASA's Mars Exploration Rover Spirit has been working since mid-2004. Areas colored blue are lower in elevation and areas colored yellow are higher in elevation. The map imagery is from the Mars Orbiter Camera on NASA's Mars Global Surveyor orbiter.

    Spirit's Long Journey, Sol 450 More than 15 months after landing on Mars, NASA's Spirit rover is still going strong, having traveled a total of 4,276 meters (2.66 miles) as of martian day, or sol, 450 (April 8, 2005). This elevation map shows the traverse followed by Spirit since arriving at the 'Columbia Hills' in June, 2004. The areas colored blue are low in elevation and areas colored yellow are high in elevation. The blue area at the foot of the 'Columbia Hills' is approximately 20 meters (66 feet) higher in elevation than the site where Spirit landed in Gusev Crater. The highest peak is on the order of 80 meters (262 feet) higher still. In other words, the hills Spirit is exploring are more than 250 feet high. The map imagery is from the Mars Orbiter Camera on NASA's Mars Global Surveyor.

  11. Coming Down from the Hill

    ERIC Educational Resources Information Center

    Frank, Fiona

    2009-01-01

    Lancaster University's Department of Continuing Education has a long tradition of engagement with older learners. Its latest innovation aims to reach out to older people sometimes suspicious of the "university on the hill". This article discusses how Lancaster University develops a "Senior Learner' Programme", which is continuing as one of the…

  12. Lunar and Planetary Science XXXV: Meteorites

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Meteorites" included the following reports:Description of a New Stony Meteorite Find from Bulloch County, Georgia; Meteorite Ablation Derived from Cosmic Ray Track Data Dhofar 732: A Mg-rich Orthopyroxenitic Achondrite Halogens, Carbon and Sulfur in the Tagish Lake Meteorite: Implications for Classification and Terrestrial Alteration; Electromagnetic Scrape of Meteorites and Probably Columbia Tiles; Pre-Atmospheric Sizes and Orbits of Several Chondrites; Research of Shock-Thermal History of the Enstatite Chondrites by Track, Thermoluminescence and Neutron-Activation (NAA) Methods; Radiation and Shock-thermal History of the Kaidun CR2 Chondrite Glass Inclusions; On the Problem of Search for Super-Heavy Element Traces in the Meteorites: Probability of Their Discovery by Three-Prong Tracks due to Nuclear Spontaneous Fission Trace Element Abundances in Separated Phases of Pesyanoe, Enstatite Achondrite; Evaluation of Cooling Rate Calculated by Diffusional Modification of Chemical Zoning: Different Initial Profiles for Diffusion Calculation; Mineralogical Features and REE Distribution in Ortho- and Clinopyroxenes of the HaH 317 Enstatite Chondrite Dhofar 311, 730 and 731: New Lunar Meteorites from Oman; The Deuterium Content of Individual Murchison Amino Acids; Clues to the Formation of PV1, an Enigmatic Carbon-rich Chondritic Clast from the Plainview H-Chondrite Regolith Breccia ;Numerical Simulations of the Production of Extinct Radionuclides and ProtoCAIs by Magnetic Flaring.

  13. Meteoritic Microfossils in Eltanin Impact Deposits

    NASA Technical Reports Server (NTRS)

    Kyte, Frank T.; Gersonde, Rainer; Kuhn, Gerhard

    2006-01-01

    We report the unique occurrence of microfossils composed largely of meteoritic ejecta particles from the late Pliocene (2.5 Ma) Eltanin impact event. These deposits are unique, recording the only known km-sized asteroid impact into a deep-ocean (5 km) basin. First discovered as in Ir anomaly in sediment cores that were collected in 1965, the deposits contain nun-sized shock-melted asteroidal material, unmelted meteorite fragments (named the Eltanin meteorite), and trace impact spherules. Two oceanographic expeditions by the FS Polarstern in 1995 and 2001 explored approximately 80,000 sq-km. of the impact region, mapping the distribution of meteoritic ejecta, disturbance of seafloor sediments by the impact, and collected 20 new cores with impact deposits in the vicinity of the Freeden Seamounts (57.3S, 90.5W). Analyses of sediment cores show that the impact disrupted sediments on the ocean floor, redepositing them as a chaotic jumble of sediment fragments overlain by a sequence of laminated sands, silts and clays deposited from the water column. Overprinted on this is a pulse of meteoritic ejecta, likely transported ballistically, then settled through the water column. At some localities, meteoritic ejecta was as much as 0.4 to 2.8 g/cm2. This is the most meteorite-rich locality known on Earth.

  14. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Chalk Hill. 9.52 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved...

  15. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Chalk Hill. 9.52 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved...

  16. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Chalk Hill. 9.52 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved...

  17. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Chalk Hill. 9.52 Section 9... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved...

  18. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Chalk Hill. 9.52 Section 9... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved...

  19. Silicate mineralogy of martian meteorites

    NASA Astrophysics Data System (ADS)

    Papike, J. J.; Karner, J. M.; Shearer, C. K.; Burger, P. V.

    2009-12-01

    Basalts and basaltic cumulates from Mars (delivered to Earth as meteorites) carry a record of the history of that planet - from accretion to initial differentiation and subsequent volcanism, up to recent times. We provide new microprobe data for plagioclase, olivine, and pyroxene from 19 of the martian meteorites that are representative of the six types of martian rocks. We also provide a comprehensive WDS map dataset for each sample studied, collected at a common magnification for easy comparison of composition and texture. The silicate data shows that plagioclase from each of the rock types shares similar trends in Ca-Na-K, and that K 2O/Na 2O wt% of plagioclase multiplied by the Al content of the bulk rock can be used to determine whether a rock is "enriched" or "depleted" in nature. Olivine data show that meteorite Y 980459 is a primitive melt from the martian mantle as its olivine crystals are in equilibrium with its bulk rock composition; all other olivine-bearing Shergottites have been affected by fractional crystallization. Pyroxene quadrilateral compositions can be used to isolate the type of melt from which the grains crystallized, and minor element concentrations in pyroxene can lend insight into parent melt compositions. In a comparative planetary mineralogy context, plagioclase from Mars is richer in Na than terrestrial and lunar plagioclase. The two most important factors contributing to this are the low activity of Al in martian melts and the resulting delayed nucleation of plagioclase in the crystallizing rock. Olivine from martian rocks shows distinct trends in Ni-Co and Cr systematics compared with olivine from Earth and Moon. The trends are due to several factors including oxygen fugacity, melt compositions and melt structures, properties which show variability among the planets. Finally, Fe-Mn ratios in both olivine and pyroxene can be used as a fingerprint of planetary parentage, where minerals show distinct planetary trends that may have been

  20. Martian Meteorites Record Surface Temperatures on Mars

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2005-07-01

    Using published data for argon (Ar) released when Martian meteorites are heated, David Shuster (California Institute of Technology, now at Berkeley Geochronology Center, Berkeley, CA) and Benjamin Weiss (Massachusetts Institute of Technology) show that the nakhlite group of Martian meteorites and unique Martian meteorite ALH 84001 were probably not heated above about 0 degree C for most of their histories. This indicates that the surface of Mars has been cold for almost four billion years. If a warm, wet environment existed on Mars (inferred from previous studies of surface features and geochemical parameters), it occurred before four billion years ago.

  1. The Mazapil meteorite: From paradigm to periphery

    NASA Astrophysics Data System (ADS)

    Beech, Martin

    2002-05-01

    The remarkable fact about the Mazapil meteorite is that it fell on the same night, in 1885, that the Andromedid meteor shower underwent a spectacular outburst. The simultaneity of these two events has driven speculation ever since. From circa 1886 to circa 1950 the circumstances of the Mazapil fall were taken, by a number of researchers, as the paradigm that demonstrated the fact that comets were actually swarms of meteoritic boulders. Beginning circa 1950, however, most researchers began to adopted the stance that the timing of the Mazapil fall was nothing more than pure coincidence. The reason behind this change in interpretation stemmed from, amongst other factors, the fact that none of the prominent annual meteor showers could be clearly shown to deliver meteorites. Also, with the introduction of the icy-conglomerate model for cometary nuclei, by F. Whipple in the early 1950s, it became increasingly clear that only exceptional circumstances would allow for the presence of large meteoritic bodies in cometary streams. Further, by the mid 1960s it had been shown that meteorites could, in fact, be delivered to the Earth from the main belt asteroid region via gravitational resonances. With the removal of the dynamical 'barrier' against the delivery of meteorites from the asteroid region, the idea that the Mazapil meteorite could have been part of the Andromedid stream fell into complete disfavor. This being said, we nonetheless present the results of a study concerning the possible properties of the parent object to the Mazapil meteorite based upon the assumption that it was a member of the Andromedid stream. This study is presented to illustrate the point that while cometary showers do not yield meteorites on the ground, this does not, in fact, substantiate the argument that no meteoritic bodies reside in cometary streams. Indeed, we find no good reason to suppose that an object with the characteristics of the Mazapil meteorite could not have been delivered from

  2. Moessbauer spectroscopy of the SNC meteorite Zagami

    NASA Technical Reports Server (NTRS)

    Agerkvist, D. P.; Vistisen, L.

    1993-01-01

    We have performed Mossbauer spectroscopy on two different pieces of the meteorite Zagami belonging to the group of SNC meteorites. In one of the samples we found a substantial amount of olivine inter grown with one kind of pyroxene, and also another kind of pyroxene very similar to the pyroxene in the other sample we examined. Both samples showed less than 1 percent of Fe(3+) in the silicate phase. The group of SNC meteorites called shergottites, to which Zagami belongs, are achondrites whose texture, mineralogy and composition resembles those of terrestrial diabases. The results from the investigation are presented.

  3. Microfossils in CI and CO Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Rozanov, Alexei Y.; Jerman, Gregory; Costen, James

    2003-01-01

    Secondary and backscatter electron images and x-ray spectral data of selected CI (Alais, Orgueil, and Tagish Lake) and CO3 (Rainbow and Dar a1 Gani 749) carbonaceous meteorites have recently been obtained using Field Emission and Environmental Scanning Electron Microscopes These studies indicate the presence of a large assemblage of biomarkers and complex lithified and carbonized remains of bodies that we interpret as indigenous microfossils. We discuss the meteorites, provide images of many of the biogenic forms found embedded in the freshly fractured meteorite surfaces.

  4. The Kunashak meteorite: New data on mineralogy

    NASA Astrophysics Data System (ADS)

    Erokhin, Yu. V.; Koroteev, V. A.; Khiller, V. V.; Burlakov, E. V.; Ivanov, K. S.; Kleimenov, D. A.

    2015-10-01

    Add info about the mineral composition of the Kunashak meteorite that fell in the Chelyabinsk region in 1949. It was found that the cosmic substance is composed of olivine (chrysolite), orthopyroxene (bronzite), clinopyroxene (augite), plagioclase (albite), maskelynite, chromite, magnetite, wustite, ilmenite, metals iron and nickel (kamacite and taenite), sulphides (troilite and pentlandite), chlorapatite and merrillite. This augite, ilmenite, pentlandite and chlorapatite identified in the Kunashak meteorite for the first time. For all minerals presents data on the chemical composition. Himself meteorite is an ordinary chondrite stone and belongs to petrological type L5-L6.

  5. Weathering of stony meteorites in Antarctica

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1986-01-01

    Weathering produces undesirable physical, chemical, and isotopic changes that might disturb the records of cosmochemical evolution that are sought in meteorites. Meteorites are physically disintegrated by crack propagation phenomena, including ice riving and secondary mineral riving, and are probably abraded by wind that is laden with ice crystals or dust particles. Chemical weathering proceeds by oxidation, hydration, carbonation, and solution and produces a variety of secondary minerals and mineraloids. Differential weathering under freezing conditions is discussed, as well as, the mineralogy of weathering products. Furthermore, the use of Antarctic alteration of meteorites could be used as an excellent analog for weathering on Mars or on cometary bodies.

  6. Magnetic minerals of the chelyabinsk meteorite

    NASA Astrophysics Data System (ADS)

    Markov, G. P.; Pecherskii, D. M.; Tsel'movich, V. A.

    2015-09-01

    Eight samples of the Chelyabinsk meteorite were studied using thermomagnetic and electron microprobe analyses; the hysteresis loop characteristics were also measured. The main magnetic minerals of the meteorite are represented by two groups of Fe-Ni alloys (native Fe minerals) with various concentrations of nickel and iron sulfides. A small number of magnetite balls were found. They are probably formed due to oxidation of troilite and other Fe sulfides as a result of melting of the meteorite due to passage through the Earth's atmosphere. The observed effect of the primary hysteresis loop constriction is probably connected with prolonged annealing of a celestial body before its transition into the meteoroid state.

  7. Measured microwave scattering cross sections of three meteorite specimens

    NASA Technical Reports Server (NTRS)

    Hughes, W. E.

    1972-01-01

    Three meteorite specimens were used in a microwave scattering experiment to determine the scattering cross sections of stony meteorites and iron meteorites in the frequency range from 10 to 14 GHz. The results indicate that the stony meteorites have a microwave scattering cross section that is 30 to 50 percent of their projected optical cross section. Measurements of the iron meteorite scattering were inconclusive because of specimen surface irregularities.

  8. Zirconium and hafnium in meteorites

    NASA Technical Reports Server (NTRS)

    Ehmann, W. D.; Chyi, L. L.

    1974-01-01

    The abundances of zirconium and hafnium have been determined in nine stony meteorites by a new, precise neutron-activation technique. The Zr/Hf abundance ratios for the chondrites vary in a rather narrow range, consistent with previously published observations from our group. Replicate analyses of new, carefully selected clean interior samples of the Cl chondrite Orgueil yield mean zirconium and hafnium abundances of 5.2 and 0.10 ppm, respectively. These abundances are lower than we reported earlier for two Cl chondrite samples which we now suspect may have suffered contamination. The new Cl zirconium and hafnium abundances are in closer agreement with predictions based on theories of nucleosynthesis than the earlier data.

  9. On the origin of Hill's causal criteria.

    PubMed

    Morabia, A

    1991-09-01

    The rules to assess causation formulated by the eighteenth century Scottish philosopher David Hume are compared to Sir Austin Bradford Hill's causal criteria. The strength of the analogy between Hume's rules and Hill's causal criteria suggests that, irrespective of whether Hume's work was known to Hill or Hill's predecessors, Hume's thinking expresses a point of view still widely shared by contemporary epidemiologists. The lack of systematic experimental proof to causal inferences in epidemiology may explain the analogy of Hume's and Hill's, as opposed to Popper's, logic.

  10. Comparison of lunar rocks and meteorites: Implications to histories of the moon and parent meteorite bodies

    NASA Technical Reports Server (NTRS)

    Prinz, M.; Fodor, R. V.; Keil, K.

    1977-01-01

    There are many similarities between lunar samples and stone meteorites. Lunar samples, especially from the highlands, indicate that they have been affected by complex and repeated impact processes. Similar complex and repeated impact processes have also been operative on the achondritic and chondritic meteorites. Similarities between lunar and meteoritic rocks are discussed as follows: (1) Monomict and polymict breccias occur in lunar rocks, as well as in achondritic and chondritic meteorites, having resulted from complex and repeated impact processes; (2) Chondrules are present in lunar meteorites, as well as in a few achondritic and most chondritic meteorites. They apparently crystallized spontaneously from molten highly supercooled droplets which may have formed from impact melts or, perhaps, volcanic processes (as well as from the solar nebula, in the case of meteoritic chondrites); (3) Lithic fragments vary from little modified (relative to the apparent original texture) to partly or completely melted and recrystallized lithic fragments. Their detailed study allows conclusions to be drawn about their parent rock types and their origin, thereby gaining insight into preimpact histories of lunar and meteoritic breccias. There is evidence that cumulate rocks were involved in the early history of both moon and parent meteorite bodies.

  11. The natural thermoluminescence of meteorites. II - Meteorite orbits and orbital evolution

    NASA Technical Reports Server (NTRS)

    Benoit, P. H.; Sears, D. W. G.; Mckeever, S. W. S.

    1991-01-01

    The present consideration of natural thermoluminescence (TL) data for 26 meteorites leads to calculation results for equilibrium natural TL level in ordinary chondrites that are indicative of TL's usefulness as an indicator of perihelion. Comparisons of data with cosmic ray exposure ages shows natural TL levels to be partly related to exposure age; meteorites with high exposure ages have generally lower ranges of natural TL than those with low ages, perhaps reflecting orbital evolution in light of the evolution of mature meteorite orbits to lower perihelia. It is confirmed that only a small proportion of meteorites have had low-perihelia orbits over the most recent 100,000 years.

  12. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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....

  13. Allan Variance Computed in Space Domain: Definition and Application to InSAR Data to Characterize Noise and Geophysical Signal.

    PubMed

    Cavalié, Olivier; Vernotte, François

    2016-04-01

    The Allan variance was introduced 50 years ago for analyzing the stability of frequency standards. In addition to its metrological interest, it may be also considered as an estimator of the large trends of the power spectral density (PSD) of frequency deviation. For instance, the Allan variance is able to discriminate different types of noise characterized by different power laws in the PSD. The Allan variance was also used in other fields than time and frequency metrology: for more than 20 years, it has been used in accelerometry, geophysics, geodesy, astrophysics, and even finances. However, it seems that up to now, it has been exclusively applied for time series analysis. We propose here to use the Allan variance on spatial data. Interferometric synthetic aperture radar (InSAR) is used in geophysics to image ground displacements in space [over the synthetic aperture radar (SAR) image spatial coverage] and in time thanks to the regular SAR image acquisitions by dedicated satellites. The main limitation of the technique is the atmospheric disturbances that affect the radar signal while traveling from the sensor to the ground and back. In this paper, we propose to use the Allan variance for analyzing spatial data from InSAR measurements. The Allan variance was computed in XY mode as well as in radial mode for detecting different types of behavior for different space-scales, in the same way as the different types of noise versus the integration time in the classical time and frequency application. We found that radial Allan variance is the more appropriate way to have an estimator insensitive to the spatial axis and we applied it on SAR data acquired over eastern Turkey for the period 2003-2011. Spatial Allan variance allowed us to well characterize noise features, classically found in InSAR such as phase decorrelation producing white noise or atmospheric delays, behaving like a random walk signal. We finally applied the spatial Allan variance to an InSAR time

  14. Allan Variance Computed in Space Domain: Definition and Application to InSAR Data to Characterize Noise and Geophysical Signal.

    PubMed

    Cavalié, Olivier; Vernotte, François

    2016-04-01

    The Allan variance was introduced 50 years ago for analyzing the stability of frequency standards. In addition to its metrological interest, it may be also considered as an estimator of the large trends of the power spectral density (PSD) of frequency deviation. For instance, the Allan variance is able to discriminate different types of noise characterized by different power laws in the PSD. The Allan variance was also used in other fields than time and frequency metrology: for more than 20 years, it has been used in accelerometry, geophysics, geodesy, astrophysics, and even finances. However, it seems that up to now, it has been exclusively applied for time series analysis. We propose here to use the Allan variance on spatial data. Interferometric synthetic aperture radar (InSAR) is used in geophysics to image ground displacements in space [over the synthetic aperture radar (SAR) image spatial coverage] and in time thanks to the regular SAR image acquisitions by dedicated satellites. The main limitation of the technique is the atmospheric disturbances that affect the radar signal while traveling from the sensor to the ground and back. In this paper, we propose to use the Allan variance for analyzing spatial data from InSAR measurements. The Allan variance was computed in XY mode as well as in radial mode for detecting different types of behavior for different space-scales, in the same way as the different types of noise versus the integration time in the classical time and frequency application. We found that radial Allan variance is the more appropriate way to have an estimator insensitive to the spatial axis and we applied it on SAR data acquired over eastern Turkey for the period 2003-2011. Spatial Allan variance allowed us to well characterize noise features, classically found in InSAR such as phase decorrelation producing white noise or atmospheric delays, behaving like a random walk signal. We finally applied the spatial Allan variance to an InSAR time

  15. Life on Mars: Evidence from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    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.

  16. The Meteoritical Bulletin, No. 87, 2003 July

    USGS Publications Warehouse

    Russell, S.S.; Zipfel, J.; Folco, L.; Jones, R.; Grady, M.M.; McCoy, T.; Grossman, J.N.

    2003-01-01

    Meteoritical Bulletin No. 87 lists information for 1898 newly classified meteorites, comprising 1048 from Antarctica, 462 from Africa, 356 from Asia (355 of which are from Oman), 18 from North America, 5 from South America, 5 from Europe, and 3 from Australia. Information is provided for 10 falls (Beni M'hira, Elbert, Gasseltepaoua, Hiroshima, Kilabo, Neuschwanstein, Park Forest, Pe??, Pe??te??lkole??, and Thuathe). Two of these-Kilabo and Thuathe-fell on the same day. Orbital characteristics could be calculated for Neuschwanstein. Noteworthy specimens include 8 Martian meteorites (5 from Sahara, 2 from Oman and 1 from Antarctica), 13 lunar meteorites (all except one from Oman), 3 irons, 3 pallasites, and many carbonaceous chondrites and achondrites.

  17. Origin of Isotopically Light Nitrogen in Meteorites

    NASA Astrophysics Data System (ADS)

    Verchovsky, A. B.

    2016-08-01

    Carrier of planetary noble gases, Q, also contains isotopically light N with d15N < -150‰ and is responsible for the appearance of the light N in many types of meteorites such as CR, CO, CM and ureilites.

  18. Consortium Study of the Chelyabinsk Meteorite

    NASA Technical Reports Server (NTRS)

    Righter, K.; Fries, M. D.; Gibson, E. K.; Harrington, R.; Keller, L. P.; McCoy, T. J.; Morris, R. V.; Nagao, K.; Nakamura-Messenger, K.; Niles, P.; Nyquist, L.; Park, J.; Peng, Z. X.; Shih, C.-Y.; Simon, J. I.; Zeigler, R. A.

    2013-01-01

    On February 15, 2013 approximately 17 m asteroid hit Earth, causing shock waves and air blasts over a portion of Russia. A significant amount of material has been recovered from this meteorite fall, officially named Chelyabinsk.

  19. Frequency Spectra of Magnetoacoustic Emission in Meteorites

    NASA Astrophysics Data System (ADS)

    Ivanchenko, S. V.; Grokhovsky, V. I.; Kolchanov, N. N.

    2016-08-01

    We analyzed the magnetoacoustic emission spectra of iron meteorites and their industrial analogs. The revealed differences in signal amplitude, position and width of the peaks are associated with the features of structure and the magnetic texture.

  20. Microfossils, biominerals, and chemical biomarkers in meteorites

    NASA Astrophysics Data System (ADS)

    Hoover, Richard B.; Rozanov, Alexei Y.

    2003-01-01

    The discovery of biominerals, chemical biomarkers and evidence of microfossils in the Mars meteorite (ALH84001) stimulated research into biomarkers, microbial extremophiles and provided impetus to the newly emerging fields of Astrobiology and Bacterial Paleontology. The debate following the ALH84001 results has highlighted the importance of developing methodologies for recognition of mineral and elemental bioindicators, chemical biomarkers and microfossils in terrestrial rocks and meteorites prior to sample return missions to comets, asteroids, and Mars. Comparative studies of living and fossil micro-organisms and biomarkers are vital to developing expertise needed to recognize indigenous biosignatures and recent contaminants. This paper reviews elemental and mineral bioindicators, chemical biomarkers and keropgen in terrestrial rocks and meteorites. Electron Microscopy images of hyperthermophilic nanobacteria, sulfur and sulfate reducing bacteria, and mineralized microfossils and kerogen found in-situ in carbonaceous meteorite rock matrix are presented.

  1. The Meteoritical Bulletin, No. 81, 1997 July

    USGS Publications Warehouse

    Grossman, J.N.

    1997-01-01

    Meteoritical Bulletin, No. 81 lists 181 new meteorites. Noteworthy among these are a new lunar meteorite (Dar al Gani 262), four observed falls (Dong Ujimqin Qi, Galkiv, Mount Tazerzait, and Piplia Kalan), four irons (Albion, Great Sand Sea 003, Hot Springs, and Mont Dieu), two mesosiderites (Dong Ujimqin Qi and Lamont), an acapulcoite (FRO 95029), a eucrite (Piplia Kalan), two probably-paired ureilites (Dar al Gani 164 and 165), an R chondrite (Hammadah al Hamra 119), an ungrouped type-3 chondrite (Hammadah al Hamra 180), a highly unequilibrated ordinary chondrite (Wells, LL3.3), and a variety of carbonaceous and unequilibrated ordinary chondrites from Libya and Antarctica. All italicized abbreviations refer to addresses listed in the appendix. ?? Meteoritical Society, 1997.

  2. Myelination Delay and Allan-Herndon-Dudley Syndrome Caused by a Novel Mutation in the SLC16A2 Gene.

    PubMed

    La Piana, Roberta; Vanasse, Michel; Brais, Bernard; Bernard, Genevieve

    2015-09-01

    Allan-Herndon-Dudley syndrome is an X-linked disease caused by mutations in the solute carrier family 16 member 2 (SLC16A2) gene. As SLC16A2 encodes the monocarboxylate transporter 8 (MCT8), a thyroid hormone transporter, patients with Allan-Herndon-Dudley syndrome present a specific altered thyroid hormone profile. Allan-Herndon-Dudley syndrome has been associated with myelination delay on the brain magnetic resonance imaging (MRI) of affected subjects. We report a patient with Allan-Herndon-Dudley syndrome characterized by developmental delay, hypotonia, and delayed myelination caused by a novel SLC16A2 mutation (p.L291R). The thyroid hormones profile in our patient was atypical for Allan-Herndon-Dudley syndrome. The follow-up examinations showed that the progression of the myelination was not accompanied by a clinical improvement. Our paper suggests that SLC16A2 mutations should be investigated in patients with myelination delay even when the thyroid function is not conclusively altered.

  3. Antarctic Meteorite Newsletter, volume 8, number 1

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Preliminary descriptions and classifications of meteorites examined since the July 1984 newsletter are presented. Each macroscopic description summarizes features that were visible to the eye (with, at most, 50X magnification). Each thin section description represents features that were found in a survey-level examination of a polished thin section that was prepared from a small (usually extrior) chip of the meteorite. Classification is based on microscopic petrography and reconnaissance-level electron-probe microanalyses.

  4. Spallogenic origin of nuclei in meteorites

    NASA Technical Reports Server (NTRS)

    Zanda, B.; Audouze, J.

    1985-01-01

    Results obtained from a model built to evaluate the different interactions between cosmic rays and meteorites are presented. The model, computes, fluxes as a function of depth inside the meteorite, taking into account energy losses by ionization and spallation reactions which induce both particle destruction and production. This procedure, in which particle fluxes and cross sections are treated independently from each other, differs significantly from the thick target approach based on the measurement of spallation products generated in accelerator experiments.

  5. The Old Woman, California, IIAB iron meteorite

    NASA Astrophysics Data System (ADS)

    Plotkin, Howard; Clarke, Roy S.; McCoy, Timothy J.; Corrigan, Catherine M.

    2012-05-01

    The Old Woman meteorite, discovered in March 1976 by two prospectors searching for a fabled lost Spanish gold mine in mountains ˜270 km east of Los Angeles, has achieved the status of a legend among meteorite hunters and collectors. The question of the ownership of the 2753 kg group IIAB meteorite, the second largest ever found in the United States (34°28'N, 115°14'W), gave rise to disputes involving the finders, the Bureau of Land Management, the Secretary of the Department of the Interior, the State of California, the California members of the U.S. Congress, various museums in California, the Smithsonian Institution, and the Department of Justice. Ultimately, ownership of the meteorite was transferred to the Smithsonian under the powers of the 1906 Antiquities Act, a ruling upheld in a U.S. District Court and a U.S. Court of Appeals. After additional debate, the Smithsonian removed a large cut for study and curation, and for disbursement of specimens to qualified researchers. The main mass was then returned to California on long-term loan to the Bureau of Land Management's Desert Discovery Center in Barstow. The Old Woman meteorite litigation served as an important test case for the ownership and control of meteorites found on federal lands. The Old Woman meteorite appears to be structurally unique in containing both hexahedral and coarsest octahedral structures in the same mass, unique oriented schreibersites within hexahedral areas, and polycrystalline parent austenite crystals. These structures suggest that different portions of the meteorite may have transformed via different mechanisms upon subsolidus cooling, making the large slices of Old Woman promising targets for future research.

  6. Noble Gases in the Chelyabinsk Meteorites

    NASA Technical Reports Server (NTRS)

    Haba, Makiko K.; Sumino, Hirochika; Nagao, Keisuke; Mikouchi, Takashi; Komatsu, Mutsumi; Zolensky, Michael E.

    2014-01-01

    The Chelyabinsk meteorite fell in Russia on February 15, 2013 and was classified as LL5 chondrite. The diameter before it entered the atmosphere has been estimated to be about 20 m [1]. Up to now, numerous fragments weighing much greater than 100 kg in total have been collected. In this study, all noble gases were measured for 13 fragments to investigate the exposure history of the Chelyabinsk meteorite and the thermal history of its parent asteroid.

  7. Estimated Optical Constants of Tagish Lake Meteorite

    NASA Technical Reports Server (NTRS)

    Roush, Ted L.; Fonda, Mark (Technical Monitor)

    2002-01-01

    The visible, near-infrared, and mid-infrared (0.3-25 micron) real and imaginary indices of refraction are derived from reflectance measurements of the Tagish Lake meteorite. These are compared to some real and imaginary indices of refraction of the individual minerals composing the Tagish Lake meteorite. From this comparison it is clear that the imaginary indices of several individual minerals contribute to the estimated imaginary index of the Tagish Lake.

  8. GEOCHEMISTRY OF MAJUBA HILL, NEVADA.

    USGS Publications Warehouse

    Wenrich, Karen J.; Mascarenas, Joseph F.; Silberman, Miles L.

    1984-01-01

    Majuba Hill is the erosional remnant of a mineralized volcanic complex of rhyolite porphyry stocks, dikes, sills and irregular masses of breccia intruded into Triassic(? ) argillites. Majuba Hill is best known for its Cu and Sn ore; in addition, it was mineralized with other metals of possible economic significance, most notably, Mo, Ag, and U. Although this is an intrusive complex with no evidence of any extrusive phases, it was intruded sufficiently near the surface to develop a porphyritic texture. Intense sericitic and argillic alteration affected all stages of intrusion. Fresh rocks were not available for K-Ar analyses. Several samples of feldspars and sericite from altered zones yielded K-Ar ages for the alteration of 24. 7 to 25. 5 m. y. The tight clustering of ages suggests that all stages of the complex were altered within less than 1 m. y.

  9. Keto-acids in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, G.; Chang, P. M.; Dugas, A.; Byrd, A.; Chang, P. M.; Washington, N.

    2005-01-01

    The Murchison and Murray meteorites are the best-characterized carbonaceous meteorites with respect to organic chemistry and are generally used as references for organic compounds in extraterrestrial material. Among the classes of organic compounds found in these meteorites are amino acids, carboxylic acids, hydroxy acids, purines, and pyrimidines. Such compounds, important in contemporary biochemistry, are thought to have been delivered to the early Earth in asteroids and comets and may have played a role in early life and/or the origin of life. Absent among (today's) critically important biological compounds reported in carbonaceous meteorites are keto acids, i.e., pyruvic acid, acetoacetic acid, and higher homologs. These compounds are key intermediates in such critical processes as glycolysis and the citric acid cycle. In this study several individual meteoritic keto acids were identified by gas chromatography-mass spectrometry (GC-MS) (see figure below). All compounds were identified as their trimethylsilyl (TMS), isopropyl ester (ISP), and tert-butyldimethylsilyl (tBDMS) derivatives. In general, the compounds follow the abiotic synthesis pattern of other known meteorite classes of organic compounds [1,2]: a general decrease in abundance with increasing carbon number within a class of compounds and many, if not all, possible isomers present at a given carbon number. The majority of the shown compounds was positively identified by comparison of their mass spectra to commercially available standards or synthesized standards.

  10. Lunar and Meteorite Sample Disk for Educators

    NASA Technical Reports Server (NTRS)

    Foxworth, Suzanne; Luckey, M.; McInturff, B.; Allen, J.; Kascak, A.

    2015-01-01

    NASA Johnson Space Center (JSC) has the unique responsibility to curate NASA's extraterrestrial samples from past and future missions. Curation includes documentation, preservation, preparation and distribution of samples for research, education and public outreach. Between 1969 and 1972 six Apollo missions brought back 382 kilograms of lunar rocks, core and regolith samples, from the lunar surface. JSC also curates meteorites collected from a US cooperative effort among NASA, the National Science Foundation (NSF) and the Smithsonian Institution that funds expeditions to Antarctica. The meteorites that are collected include rocks from Moon, Mars, and many asteroids including Vesta. The sample disks for educational use include these different samples. Active relevant learning has always been important to teachers and the Lunar and Meteorite Sample Disk Program provides this active style of learning for students and the general public. The Lunar and Meteorite Sample Disks permit students to conduct investigations comparable to actual scientists. The Lunar Sample Disk contains 6 samples; Basalt, Breccia, Highland Regolith, Anorthosite, Mare Regolith and Orange Soil. The Meteorite Sample Disk contains 6 samples; Chondrite L3, Chondrite H5, Carbonaceous Chondrite, Basaltic Achondrite, Iron and Stony-Iron. Teachers are given different activities that adhere to their standards with the disks. During a Sample Disk Certification Workshop, teachers participate in the activities as students gain insight into the history, formation and geologic processes of the moon, asteroids and meteorites.

  11. Update on terrestrial ages of Antarctic meteorites

    SciTech Connect

    Welten, K C; Nishiizumi, K; Caffee, M W

    2000-01-14

    Terrestrial ages of Antarctic meteorites are one of the few parameters that will help us to understand the meteorite concentration mechanism on blue-ice fields. Traditionally, terrestrial ages were determined on the basis of {sup 36}Cl in the metal phase, which has an uncertainty of about 70 ky. For young meteorites (< 40 ky), the terrestrial age is usually and most accurately determined using {sup 14}C in the stone phase. In recent years two methods have been developed which are independent of shielding effects, the {sup 10}Be-{sup 36}Cl/{sup 10}Be method and the {sup 41}Ca/{sup 36}Cl method. These methods have reduced the typical uncertainties in terrestrial ages by a factor of 2, to about 30 ky. The {sup 10}Be-{sup 36}Cl/{sup 10}Be method is quite dependent on the exposure age, which is unknown for most Antarctic meteorites. The authors therefore also attempt to use the relation between {sup 26}Al and {sup 36}Cl/{sup 26}Al to derive a terrestrial age less dependent on the exposure age. The authors have measured the concentrations of cosmogenic {sup 10}Be, {sup 26}Al and {sup 36}Cl in the metal phase of {approximately} 70 Antarctic meteorites, from more than 10 different ice-fields, including many new ones. They then discuss the trends in terrestrial ages of meteorites from different ice-fields.

  12. The organic inventory of primitive meteorites

    NASA Astrophysics Data System (ADS)

    Martins, Zita

    Carbonaceous meteorites are primitive samples that provide crucial information about the solar system genesis and evolution. This class of meteorites has also a rich organic inventory, which may have contributed the first prebiotic building blocks of life to the early Earth. We have studied the soluble organic inventory of several CR and CM meteorites, using high performance liquid chromatography with UV fluorescence detection (HPLC-FD), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Our target organic molecules include amino acids, nucleobases and polycyclic aromatic hydrocarbons (PAHs), among others. CR chondrites contain the highest amino acids concentration ever detected in a meteorite. The degree of aqueous alteration amongst this class of meteorites seems to be responsible for the amino acid distribution. Pioneering compound-specific carbon isotope measurements of nucleobases present in carbonaceous chondrites show that these compounds have a non-terrestrial origin. This suggests that components of the ge-netic code may have had a crucial role in life's origin. Investigating the abundances, distribution and isotopic composition of organic molecules in primitive meteorites significantly improves our knowledge of the chemistry of the early solar system, and the resources available for the first living organisms on Earth.

  13. Iron and Stony-iron Meteorites

    NASA Astrophysics Data System (ADS)

    Haack, H.; McCoy, T. J.

    2003-12-01

    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 and other terrestrial planets. This fact has been recognized since the work of Chladni (1794), who argued that stony-iron meteorites must have originated in outer space and fallen during fireballs and that they provide our closest analogue to the material that comprises our own planet's core. This chapter deals with our current knowledge of these meteorites. How did they form? What can they tell us about the early evolution of the solar system and its solid bodies? How closely do they resemble the materials from planetary interiors? What do we know and don't we know?Iron and stony-iron meteorites constitute ˜6% of meteorite falls (Grady, 2000). Despite their scarcity among falls, iron meteorites are our only samples of ˜75 of the ˜135 asteroids from which meteorites originate ( Keil et al., 1994; Scott, 1979; Meibom and Clark, 1999; see also Chapter 1.05), suggesting that both differentiated asteroids and the geologic processes that produced them were common.Despite the highly evolved nature of iron and stony-iron meteorites, their chemistry provides important

  14. Rocks of the Columbia Hills

    USGS Publications Warehouse

    Squyres, S. W.; Arvidson, R. E.; Blaney, D.L.; Clark, B. C.; Crumpler, L.; Farrand, W. H.; Gorevan, S.; Herkenhoff, K. E.; Hurowitz, J.; Kusack, A.; McSween, H.Y.; Ming, D. W.; Morris, R.V.; Ruff, S.W.; Wang, A.; Yen, A.

    2006-01-01

    The Mars Exploration Rover Spirit has identified five distinct rock types in the Columbia Hills of Gusev crater. Clovis Class rock is a poorly sorted clastic rock that has undergone substantial aqueous alteration. We interpret it to be aqueously altered ejecta deposits formed by impacts into basaltic materials. Wishstone Class rock is also a poorly sorted clastic rock that has a distinctive chemical composition that is high in Ti and P and low in Cr. Wishstone Class rock may be pyroclastic or impact in origin. Peace Class rock is a sedimentary material composed of ultramafic sand grains cemented by significant quantities of Mg- and Ca-sulfates. Peace Class rock may have formed when water briefly saturated the ultramafic sands and evaporated to allow precipitation of the sulfates. Watchtower Class rocks are similar chemically to Wishstone Class rocks and have undergone widely varying degrees of near-isochemical aqueous alteration. They may also be ejecta deposits, formed by impacts into Wishstone-rich materials and altered by small amounts of water. Backstay Class rocks are basalt/trachybasalt lavas that were emplaced in the Columbia Hills after the other rock classes were, either as impact ejecta or by localized volcanic activity. The geologic record preserved in the rocks of the Columbia Hills reveals a period very early in Martian history in which volcanic materials were widespread, impact was a dominant process, and water was commonly present. Copyright 2006 by the American Geophysical Union.

  15. Contemporary Inuit Traditional Beliefs Concerning Meteorites

    NASA Astrophysics Data System (ADS)

    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

  16. Allan C. Gotlib, DC, CM: A worthy Member of the Order of Canada

    PubMed Central

    Brown, Douglas M.

    2016-01-01

    On June 29, 2012, His Excellency the Right Honourable David Johnston, Governor General of Canada, announced 70 new appointments to the Order of Canada. Among them was Dr. Allan Gotlib, who was subsequently installed as a Member of the Order of Canada, in recognition of his contributions to advancing research in the chiropractic profession and its inter-professional integration. This paper attempts an objective view of his career, to substantiate the accomplishments that led to Dr. Gotlib receiving Canada’s highest civilian honour. PMID:27069273

  17. Investigation of Allan variance for determining noise spectral forms with application to microwave radiometry

    NASA Technical Reports Server (NTRS)

    Stanley, William D.

    1994-01-01

    An investigation of the Allan variance method as a possible means for characterizing fluctuations in radiometric noise diodes has been performed. The goal is to separate fluctuation components into white noise, flicker noise, and random-walk noise. The primary means is by discrete-time processing, and the study focused primarily on the digital processes involved. Noise satisfying the requirements was generated by direct convolution, fast Fourier transformation (FFT) processing in the time domain, and FFT processing in the frequency domain. Some of the numerous results obtained are presented along with the programs used in the study.

  18. PLANETARY SCIENCE: Enhanced: A Meteorite Falls on Ice.

    PubMed

    Grossman, J N

    2000-10-13

    Primitive meteorites provide a glimpse into the early history of our solar system, but some of the most primitive meteorites are also rarely found on Earth. In his Perspective, Grossman explains why the fall of the Tagish Lake meteorite on 18 January 2000 in British Columbia, Canada, was a lucky event for meteorite researchers. The first analysis of the meteorite is reported by Brown et al. Well-preserved organic matter in the meteorite provides a unique opportunity to study the nature and origin of organic matter that may have accreted on early Earth and played a role in the origin of life. PMID:17734110

  19. The Weathering of Antarctic Meteorites: Climatic Controls on Weathering Rates and Implications for Meteorite Accumulation

    NASA Technical Reports Server (NTRS)

    Benoit, P. H.; Akridge, J. M. C.; Sears, D. W. G.; Bland, P. A.

    1995-01-01

    Weathering of meteorites includes a variety of chemical and mineralogical changes, including conversion of metal to iron oxides, or rust. Other changes include the devitrification of glass, especially in fusion crust. On a longer time scale, major minerals such as olivine, pyroxene, and feldspar are partially or wholly converted to various phyllosilicates. The degree of weathering of meteorite finds is often noted using a qualitative system based on visual inspection of hand specimens. Several quantitative weathering classification systems have been proposed or are currently under development. Wlotzka has proposed a classification system based on mineralogical changes observed in polished sections and Mossbauer properties of meteorite powders have also been used. In the current paper, we discuss induced thermoluminescence (TL) as an indicator of degree of weathering of individual meteorites. The quantitative measures of weathering, including induced TL, suffer from one major flaw, namely that their results only apply to small portions of the meteorite.

  20. Guide to the US collection of antarctic meteorites 1976-1988 (everything you wanted to know about the meteorite collection). Antarctic Meteorite Newsletter, Volume 13, Number 1

    NASA Technical Reports Server (NTRS)

    Score, Roberta; Lindstrom, Marilyn M.

    1990-01-01

    The state of the collection of Antarctic Meteorites is summarized. This guide is intended to assist investigators plan their meteorite research and select and request samples. Useful information is presented for all classified meteorites from 1976 to 1988 collections, as of Sept. 1989. The meteorite collection has grown over 13 years to include 4264 samples of which 2754 have been classified. Most of the unclassified meteorites are ordinary chondrites because the collections have been culled for specimens of special petrologic type. The guide consists of two large classification tables. They are preceded by a list of sample locations and important notes to make the tables understandable.

  1. Meteorite Linked to Rock at Meridiani

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This meteorite, a basalt lava rock nearly indistinguishable from many Earth rocks, provided the first strong proof that meteorites could come from Mars. Originally weighing nearly 8 kilograms (17.6 pounds), it was collected in 1979 in the Elephant Moraine area of Antarctica. The side of the cube at the lower left in this image measures 1 centimeter (0.4 inches).

    This picture shows a sawn face of this fine-grained gray rock. (The vertical stripes are saw marks.) The black patches in the rock are melted rock, or glass, formed when a large meteorite hit Mars near the rock. The meteorite impact probably threw this rock, dubbed 'EETA79001,' off Mars and toward Antarctica on Earth. The black glass contains traces of martian atmosphere gases.

    The Mars Exploration Rover Opportunity has discovered that a rock dubbed 'Bounce' at Meridiani Planum has a very similar mineral composition to this meteorite and likely shares common origins. Bounce itself is thought to have originated outside the area surrounding Opportunity's landing site; an impact or collision likely threw the rock away from its primary home.

  2. Amino acids in the Martian meteorite Nakhla

    PubMed Central

    Glavin, Daniel P.; Bada, Jeffrey L.; Brinton, Karen L. F.; McDonald, Gene D.

    1999-01-01

    A suite of protein and nonprotein amino acids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, β-alanine, and γ-amino-n-butyric acid (γ-ABA) were the most abundant amino acids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The amino acid distribution in Nakhla, including the d/l ratios (values range from <0.1 to 0.5), is similar to what is found in bacterially degraded organic matter. The amino acids in Nakhla appear to be derived from terrestrial organic matter that infiltrated the meteorite soon after its fall to Earth, although it is possible that some of the amino acids are endogenous to the meteorite. The rapid amino acid contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth. PMID:10430856

  3. Amino acids in the Martian meteorite Nakhla

    NASA Technical Reports Server (NTRS)

    Glavin, D. P.; Bada, J. L.; Brinton, K. L.; McDonald, G. D.

    1999-01-01

    A suite of protein and nonprotein amino acids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, beta-alanine, and gamma-amino-n-butyric acid (gamma-ABA) were the most abundant amino acids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The amino acid distribution in Nakhla, including the D/L ratios (values range from <0.1 to 0.5), is similar to what is found in bacterially degraded organic matter. The amino acids in Nakhla appear to be derived from terrestrial organic matter that infiltrated the meteorite soon after its fall to Earth, although it is possible that some of the amino acids are endogenous to the meteorite. The rapid amino acid contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth.

  4. Meteorite Shower in Park Forest, Illinois

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.

    2004-08-01

    Steven Simon (University of Chicago) and seven colleagues from the University of Chicago, the Planetary Studies Foundation, Harper College, Pacific Northwest National Lab, and the Field Museum in Chicago have classified the meteorite fragments that fell on Chicago's southern suburbs on the night of March 26, 2003. Described as ".. the most densely populated region to be hit by a meteorite shower in modern times," the village of Park Forest is at the center of the strewnfield and fortuitously also happens to be home to the Simon family, who answered scores of phone calls from neighboring meteorite finders. No injuries were reported though plenty of roofs, windows, walls, and cars were hit, and the police department took individual fusion-crusted fragments into custody as evidence. Its chemical and mineralogical compositions establish the Park Forest meteorite as an L5 chondrite, one of the most primitive groups of known meteorites. It is a strongly shocked monomict breccia (a term applied to a breccia made of one kind of rock) with light-colored clasts in a very dark matrix. The team measured cosmic radionuclides in Park Forest and found nearly zero cobalt-56 and high cobalt-60, values that indicate a large preatmospheric mass. They estimate the meteoroid was at least 900 kilograms and possibly as large as 7000 kilograms before it broke apart in the atmosphere, of which only about 30 kilograms of fragments have been recovered.

  5. About 129Xe ∗ in meteoritic nanodiamonds

    NASA Astrophysics Data System (ADS)

    Fisenko, A. V.; Semjonova, L. F.

    2008-08-01

    The analysis of excess 129Xe in meteoritic nanodiamonds and the kinetics of its release during stepwise pyrolysis allow to suggest that (1) in the solar nebula 129I atoms were adsorbed onto nanodiamond grains and (or) chemisorbed by forming covalent bonds with carbon atoms. Most 129I atoms existed in a surface connected state, but a minor amount of them was in nanopores of the grains. At radioactive decay of 129I the formed 129Xe ( 129Xe ∗) was trapped by diamond grains due to nuclear recoil. (2) During thermal metamorphism or aqueous alteration, the surface-sited 129I atoms were basically lost. On the basis of these assumptions and calculated concentrations of 129Xe ∗ in meteoritic nanodiamonds it is shown that the minimum closing time of the I-Xe system for meteorites of different chemical classes and low petrologic types may be about one million years relative to the minimally thermally metamorphized CO3 meteorite ALHA 77307. With increasing metamorphic grade the closing time of the I-Xe system increases and can range up to several ten millions years. This tendency is in agreement with an onion-shell model of structure and cooling history of meteorite parent bodies where the temperature increases in the direction from surface to center of the asteroids.

  6. Keeping pace with Capitol Hill

    USGS Publications Warehouse

    Cooper, C.

    2007-01-01

    At the Capitol Hill, the legislative branch of the United States government, the work is always at pace. Working with Congress is a tough job yet, rewarding. The Congress worked hard together to serve the public interest but many big issues are one small part of what Congress does. However, many US news media do not report what the government does instead, the media report what the government argues about. The media reports the conflicts but story is always incomplete. In order for the people know what is happening to the government, contact the congressional representative to know the complete story.

  7. The Microbiological Contamination of Meteorites: A Null Hypothesis

    NASA Technical Reports Server (NTRS)

    Steele, A.; Toporski, J. K. W.; Westall, F. W.; Thomas-Keprta, K.; Gibson, E. K.; Avci, R.; Whitby, C.; McKay, D. S.; Griffin, C.

    2000-01-01

    Using 4 different techniques we have studied 9 meteorites including the Martian meteorites ALH84001 and Nakhla for terrestrial contamination in all 9 we have found evidence of terrestrial microorganisms.

  8. Meteorites and the Evolution of Our Solar System

    NASA Technical Reports Server (NTRS)

    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.

  9. Lunar and Planetary Science XXXV: Martian Meteorites: Chemical Weathering

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Martian Meteorites: Chemical Weathering" included the following reports:Chemical Weathering Records of Martian Soils Preserved in the Martian Meteorite EET79001; Synchrotron X-Ray Diffraction Analysis of Meteorites in Thin Section: Preliminary Results; A Survey of Olivine Alteration Products Using Raman Spectroscopy; and Rb-Sr and Sm-Nd Isotope Systematics of Shergottite NWA 856: Crystallization Age and Implications for Alteration of Hot Desert SNC Meteorites.

  10. Siderophile elements in brecciated HED meteorites and the nature of projectile materials in HED meteorites

    NASA Astrophysics Data System (ADS)

    Shirai, N.; Okamoto, C.; Yamaguchi, A.; Ebihara, M.

    2016-03-01

    Petrological, mineralogical and geochemical studies were performed on five brecciated HED meteorites (ALH 76005, EET 92003, LEW 85300, LEW 87026 and GRO 95633) in order to elucidate the nature of impactors on the HED parent body. Some brecciated HED meteorites contain exotic materials such as FeNi-metal grains with low Co/Ni ratios (ALH 76005, EET 92003 and GRO 95633) and carbonaceous chondrite clasts (LEW 85300) in a clastic and/or impact melt matrix. Such exotic materials were incorporated during brecciation. Platinum group element (PGE) abundances vary significantly (CI × 0.002-0.05), but are higher than those of pristine rocks from the HED parent body. The PGE ratios for the five HED meteorites are inconsistent with each other, implying that the impactor components of each HED meteorites are different from each other. The various PGE ratios are consistent with those for metals from chondrites and iron meteorites, and carbonaceous chondrites. This study provides the evidence that IAB and IVA iron meteorites, and carbonaceous chondrites (CM, CO, CV, CK, CB and CR), ordinary chondrites (L and H) and enstatite chondrite (EL) are candidates of the impactor materials on the HED parent body. It is highly probable that significant amounts of siderophile elements were incorporated into the inner solar system objects like the HED parent body from both chondritic materials and differentiated materials like iron meteorites during heavy bombardment. The HED meteorites in this study and metals from mesosiderite have different Pd/Ir ratios, probably implying that HED meteorites and mesosiderites formed either at distinct settings on one common parent body or on similar parent bodies.

  11. Concentrating Antarctic Meteorites on Blue ice Fields: The Frontier Mountain Meteorite Trap

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    The collection of meteorites in Antarctica has greatly stimulated advancement in the field of meteoritics by providing the community with significant numbers of rare and unique meteorites types and by yielding large numbers of meteorites that sample older infall epochs (Grady et al., 1998). The majority of Antarctic meteorites are found on blue ice fields, where they are thought to be concentrated by wind and glacial drift (cf. Cassidy et al., 1992). The basic "ice flow model" describes the concentration of meteorites by the stagnation or slowing of ice as it moves against a barrier located in a zone with low snow accumulation. However, our limited knowledge of the details of the actual concentration mechanisms prevents establishing firm conclusions concerning the past meteorite flux from the Antarctic record (Zolensky, 1998). The terrestrial ages of Antarctic meteorites indicate that their concentration occurs on time scales of tens to hundreds of thousands of years (Nishiizumi et al., 1989). It is a challenge to measure a mechanism that operates so slowly, and since such time scales can span more than one glacial epoch one cannot assume that the snow accumulation rates, ice velocities and directions, etc. that are measured today are representative of those extant over the age of the trap. Testing the basic "ice flow model" therefore requires the careful measurement of meteorite locations, glacialogical ice flow data, ice thicknesses, bedrock and surface topology, ice ablation and snow accumulation rates, and mass transport by wind over an extended period of time in a location where these quantities can be interpreted in the context of past glacialogical history.

  12. Meteorites: messengers from the early solar system.

    PubMed

    Hofmann, Beda A

    2010-01-01

    Meteorites are fragments from solar system bodies, dominantly asteroids. A small fraction is derived from the Moon and from Mars. These rocks tell a rich history of the early solar system and range from solids little changed since the earliest phases of solid matter condensation in the solar nebula (chondrites) to material representing asteroidal metamorphism and melting, impact processes on the Moon and even aqueous alteration near the surface of Mars. Meteorites are very rare. Currently many meteorites result from searches in Antarctica and the hot deserts of North Africa and Arabia. The present high find rate likely represents a unique short-term event, asking for a careful management of this scarce scientific resource.

  13. The source crater of martian shergottite meteorites.

    PubMed

    Werner, Stephanie C; Ody, Anouck; Poulet, François

    2014-03-21

    Absolute ages for planetary surfaces are often inferred by crater densities and only indirectly constrained by the ages of meteorites. We show that the <5 million-year-old and 55-km-wide Mojave Crater on Mars is the ejection source for the meteorites classified as shergottites. Shergottites and this crater are linked by their coinciding meteorite ejection ages and the crater formation age and by mineralogical constraints. Because Mojave formed on 4.3 billion-year-old terrain, the original crystallization ages of shergottites are old, as inferred by Pb-Pb isotope ratios, and the much-quoted shergottite ages of <600 million years are due to resetting. Thus, the cratering-based age determination method for Mars is now calibrated in situ, and it shifts the absolute age of the oldest terrains on Mars backward by 200 million years.

  14. Meteorites and the early solar system

    SciTech Connect

    Kerridge, J.F.; Matthews, M.S.

    1988-01-01

    The present work discusses topics in the source regions for meteorites, their secondary processing, irradiation effects on meteorites, solar system chronology, the early solar system, the chemistry of chondrites and the early solar system, magnetic fields in the early solar system, the nature of chondrules, micrometeorites, inhomogeneity of the nebula, the survival of presolar material in meteorites, nucleosynthesis, and the relationship between extinct radionuclides and nucleocosmochronology. Attention is given to igneous activity in the early solar system, principles of radiometric aging, the cosmochemical classification of the elements, highly labile elements, the potential significance of pristine material, the astrophysical implications of presolar grains, boundary conditions for the origin of the solar system, and iodine-xenon dating.

  15. Lafayette meteorite - Petrology and opaque mineralogy

    NASA Technical Reports Server (NTRS)

    Boctor, N. Z.; Meyer, H. O. A.; Kullerud, G.

    1976-01-01

    The Lafayette meteorite is a calcium-rich achondrite composed predominantly of cumulus clinopyroxene with minor iron-rich olivine and rare interstitial feldspar. The opaque oxide minerals are magnetite-ilmenite intergrowths, an apparently homogenous Cr-rich titaniferous magnetite, and discrete ilmenite. Pyrite, the major sulfide mineral, occasionally displays lamellar intergrowths of marcasite that appear to be of primary origin. Troilite occurs as inclusions in ilmenite or interstitial to the silicate minerals. Bulk chemical composition of the glass in the fusion crust is comparable with that of the Nakhla meteorite. The glass contains abundant skeletal crystals of magnetite as well as very rare, zoned magnetite grains with rims enriched in Mg and depleted in Ti relative to the cores. Although no brecciation is visible in the Lafayette meteorite, the presence of deformed twin lamellae in the clinopyroxene indicates some deformation has occurred.

  16. The r-PROCESS Record in Meteorites

    NASA Astrophysics Data System (ADS)

    Davis, Andrew M.

    2004-09-01

    The r-process record in bulk meteorites and components of primitive meteorites (including refractory inclusions and presolar grains) is reviewed. Small r-process excesses are seen in bulk meteorites and refractory inclusions. Large r-process enhancements have only been observed in presolar diamond. The unique properties and formation conditions of presolar diamond, high purity and high surface-to-volume ratio, may allow it to preserve an r-process signature. It is suggested that the conditions under which r-process matter is ejected from a nascent neutron star dictate that apart from diamonds, strong r-process enhancements are not to be expected in larger presolar grains and other solar system components.

  17. Workshop on Oxygen in Asteroids and Meteorites

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Contents include the following: Constraints on the detection of solar nebula's oxidation state through asteroid observation. Oxidation/Reduction Processes in Primitive Achondrites. Low-Temperature Chemical Processing on Asteroids. On the Formation Location of Asteroids and Meteorites. The Spectral Properties of Angritic Basalts. Correlation Between Chemical and Oxygen Isotopic Compositions in Chondrites. Effect of In-Situ Aqueous Alteration on Thermal Model Heat Budgets. Oxidation-Reduction in Meteorites: The Case of High-Ni Irons. Ureilite Atmospherics: Coming up for Air on a Parent Body. High Temperature Effects Including Oxygen Fugacity, in Pre-Planetary and Planetary Meteorites and Asteroids. Oxygen Isotopic Variation of Asteroidal Materials. High-Temperature Chemical Processing on Asteroids: An Oxygen Isotope Perspective. Oxygen Isotopes and Origin of Opaque Assemblages from the Ningqiang Carbonaceous Chondrite. Water Distribution in the Asteroid Belt. Comparative Planetary Mineralogy: V Systematics in Planetary Pyroxenes and fo 2 Estimates for Basalts from Vesta.

  18. Solar flare irradiation records in Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Goswami, J. N.

    1981-01-01

    The observation of tracks from solar flare heavy nuclei in Antarctic meteorite samples is reported. In an analysis of nuclear track densities in eight L and H chondrites of low metamorphic grade, it was found that two interior specimens of sample 77216, an L-3 chondrite, contain olivine grains with track densities much higher than the average track densities, indicating precompaction irradiation by solar flares in different shielding conditions. Preliminary data from mass spectroscopic analyses show a large excess of noble gases, with a Ne-20/Ne-22 ratio of greater than or equal to 10, indicating the presence of solar-type noble gas. Results of track density measurements in the other Antarctic meteorites range from 10,000 to 4,000,000/sq cm, which is within the range observed in non-Antarctic L-group meteorites

  19. Meteorites: messengers from the early solar system.

    PubMed

    Hofmann, Beda A

    2010-01-01

    Meteorites are fragments from solar system bodies, dominantly asteroids. A small fraction is derived from the Moon and from Mars. These rocks tell a rich history of the early solar system and range from solids little changed since the earliest phases of solid matter condensation in the solar nebula (chondrites) to material representing asteroidal metamorphism and melting, impact processes on the Moon and even aqueous alteration near the surface of Mars. Meteorites are very rare. Currently many meteorites result from searches in Antarctica and the hot deserts of North Africa and Arabia. The present high find rate likely represents a unique short-term event, asking for a careful management of this scarce scientific resource. PMID:21138163

  20. The source crater of martian shergottite meteorites.

    PubMed

    Werner, Stephanie C; Ody, Anouck; Poulet, François

    2014-03-21

    Absolute ages for planetary surfaces are often inferred by crater densities and only indirectly constrained by the ages of meteorites. We show that the <5 million-year-old and 55-km-wide Mojave Crater on Mars is the ejection source for the meteorites classified as shergottites. Shergottites and this crater are linked by their coinciding meteorite ejection ages and the crater formation age and by mineralogical constraints. Because Mojave formed on 4.3 billion-year-old terrain, the original crystallization ages of shergottites are old, as inferred by Pb-Pb isotope ratios, and the much-quoted shergottite ages of <600 million years are due to resetting. Thus, the cratering-based age determination method for Mars is now calibrated in situ, and it shifts the absolute age of the oldest terrains on Mars backward by 200 million years. PMID:24603150

  1. Analytical Carbon Probe Measurements on Iron Meteorites

    NASA Astrophysics Data System (ADS)

    Meibom, A.; Rasmussen, K. L.; Hornshoj, P.; Rud, N.; Heinemeier, J.

    1992-07-01

    Using a tandem accelerator the process ^12C(d,p)^13C reaction has been used to measure the carbon contents of stony meteorites (Oberheuser et al. 1983; Van der Stap et al. 1986). Carbon has been measured in iron meteorites primarily by combustion and subsequent determination of the amount of CO2 produced (Moore et al. 1969; Lewis and Moore 1971). We use a tandem accelerator and the ^12C(d,p)^13C reaction to non-destructively measure the carbon contents of iron meteorites. The precise measurement of carbon in iron meteorites might prove to be important for determination of metallographical cooling rates. The effect of the analogous element P on the Fe-Ni phase diagram and diffusion coefficients is pronounced, but investigations of the similar effects for carbon have never been undertaken due to lack of proper analytical tools with the needed detection limit and spatial resolution. Very low abundance levels can be expected. Our estimated detection limit for carbon is ca. 10 micrograms/g, although we have not yet achieved this level (Haack 1991). The surface contamination on the samples is a severe problem in such low concentration ranges. In order to remove surface contamination we use an argon sputter source to clean off the surface layer. We have prepared standards for irons as well as for silicates. References: Haack, H. (1991) Unpublished Thesis. Lewis, C.F. and Moore, C.B. (1971) Meteoritics, 6, 195-205. Moore, C.B., Lewis, C.F., and Nava, D. (1969) In: Meteorite Research (ed. P. Millman), 738-748. Oberheuser, G., Katherin, H., Demortier, G., Gonska, H., and Freund, F. (1983) Geochim. Cosmochim. Acta, 47, 1117-1129. Van der Stap, C.C.A.H., Heymann, D., Vis, R.D., and Verheul, H. (1986) Proc. LPSC 16th, JGR, 91, D373-D377.

  2. Nuclide production in (very) small meteorites

    NASA Technical Reports Server (NTRS)

    Arnold, J. R.; Nishiizumi, K.

    1986-01-01

    One of the most interesting open questions in the study of cosmic-ray effects in meteorites is the expected behavior of objects which are very small compared to the mean interaction length of primary galactic cosmic ray (GCR) particles. A reasonable limit might be a pre-atmospheric radius of 5 gram/cm(2), or 1.5 cm for chondrites. These are interesting for at least three reasons: (1) this is a limiting case for large objects, and can help us make better models; (2) this size is intermediate between usual meteorites and irradiated grams (spherules); and (3) these are the most likely objects to show solar cosmic ray (SCR) effects. Reedy (1984) has recently proposed a model for production by GCR of radioactive and stable nuclides in spherical meteorites. Very small objects are expected to deviate from this model in the direction of fewer secondary particles (larger spectral shape parameter), at all depths. The net effect will be significantly lower production of such low-energy products as Mn-53 and Al-26. The SCR production of these and other nuclides will be lower, too, because meteorite orbits extend typically out into the asteroid belt, and the mean SCR flux must fall off approximately as r(-2) with distance from the Sun. Kepler's laws insure that for such orbits most of the exposure time is spent near aphelion. None the less the equivalent mean exposure distance, R(exp), is slightly less than the semimajor axis A because of the weighting by R(-2). For the three meteorite orbits we have, R(exp) has a narrow range, from about 1.6 to 2.1 a.u. This is probably true for the great majority of meteorites.

  3. Amino Acid Degradation after Meteoritic Impact Simulation

    NASA Technical Reports Server (NTRS)

    Bertrand, M.; Westall, F.; vanderGaast, S.; Vilas, F.; Hoerz, F.; Barnes, G.; Chabin, A.; Brack, A.

    2008-01-01

    Amino acids are among the most important prebiotic molecules as it is from these precursors that the building blocks of life were formed [1]. Although organic molecules were among the components of the planetesimals making up the terrestrial planets, large amounts of primitive organic precursor molecules are believed to be exogenous in origin and to have been imported to the Earth via micrometeorites, carbonaceous meteorites and comets, especially during the early stages of the formation of the Solar System [1,2]. Our study concerns the hypothesis that prebiotic organic matter, present on Earth, was synthesized in the interstellar environment, and then imported to Earth by meteorites or micrometeorites. We are particularly concerned with the formation and fate of amino acids. We have already shown that amino acid synthesis is possible inside cometary grains under interstellar environment conditions [3]. We are now interested in the effects of space conditions and meteoritic impact on these amino acids [4-6]. Most of the extraterrestrial organic molecules known today have been identified in carbonaceous chondrite meteorites [7]. One of the components of these meteorites is a clay with a composition close to that of saponite, used in our experiments. Two American teams have studied the effects of impact on various amino acids [8,9]. [8] investigated amino acids in saturated solution in water with pressure ranges between 5.1 and 21 GPa and temperature ranges between 412 and 870 K. [9] studied amino acids in solid form associated with and without minerals (Murchison and Allende meteorite extracts) and pressure ranges between 3 and 30 GPa. In these two experiments, the amino acids survived up to 15 GPa. At higher pressure, the quantity of preserved amino acids decreases quickly. Some secondary products such as dipeptides and diketopiperazins were identified in the [8] experiment.

  4. Mineralogical Study of Reddish Olivine in Dhofar 307 Lunar Meteorite: Comparison with Brown Olivine in Martian Meteorites

    NASA Astrophysics Data System (ADS)

    Takenouchi, A.; Mikouchi, T.

    2016-08-01

    We compared reddish olivine in Dhofar 307 lunar meteorite to brown olivine in martian meteorites and indicate a possibility of its shock origin. This result suggests that olivine darkening may have widely occurred on the surface of large bodies.

  5. Workshop on Meteorites From Cold and Hot Deserts

    NASA Technical Reports Server (NTRS)

    Schultz, Ludolf (Editor); Annexstad, John O. (Editor); Zolensky, Michael E. (Editor)

    1994-01-01

    The current workshop was organized to address the following points: (1) definition of differences between meteorites from Antarctica, hot deserts, and modern falls; (2) discussion of the causes of these differences; (3) implications of possible different parent populations, infall rates, weathering processes, etc.; (4) collection, curation, and distribution of meteorites; and (5) planning and coordination of future meteorite searches.

  6. Meteorites and their parent bodies: Evidence from oxygen isotopes

    NASA Technical Reports Server (NTRS)

    Clayton, R. N.

    1978-01-01

    Isotopic abundance variations among meteorites are used to establish genetic associations between meteorite classes. Oxygen isotope distributions between group II E irons with H-group ordinary chondrites and enstatic meteorites indicate that the parent bodies were formed out of pre-solar material that was not fully mixed at the time condensation occurred within the solar nebula.

  7. Microfossils of Cyanobacteria in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.

    2007-01-01

    During the past decade, Environmental and Field Emission Scanning Electron Microscopes have been used at the NASA/Marshall Space Flight Center to investigate freshly fractured interior surfaces of a large number of different types of meteorites. Large, complex, microfossils with clearly recognizable biological affinities have been found embedded in several carbonaceous meteorites. Similar forms were notably absent in all stony and nickel-iron meteorites investigated. The forms encountered are consistent in size and morphology with morphotypes of known genera of Cyanobacteria and microorganisms that are typically encountered in associated benthic prokaryotic mats. Even though many coccoidal and isodiametric filamentous cyanobacteria have a strong morphological convergence with some other spherical and filamentous bacteria and algae, many genera of heteropolar cyanobacteria have distinctive apical and basal regions and cellular differentiation that makes it possible to unambiguously recognize the forms based entirely upon cellular dimensions, filament size and distinctive morphological characteristics. For almost two centuries, these morphological characteristics have historically provided the basis for the systematics and taxonomy of cyanobacteria. This paper presents ESEM and FESEM images of embedded filaments and thick mats found in-situ in the Murchison CM2 and Orgueil cn carbonaceous meteorites. Comparative images are also provided for known genera and species of cyanobacteria and other microbial extremophiles. Energy Dispersive X-ray Spectroscopy (EDS) studies indicate that the meteorite filaments typically exhibit dramatic chemical differentiation with distinctive difference between the possible microfossil and the meteorite matrix in the immediate proximity. Chemical differentiation is also observed within these microstructures with many of the permineralized filaments enveloped within electron transparent carbonaceous sheaths. Elemental distributions of

  8. Antarctic Meteorite Newsletter, volume 9, no. 2

    NASA Technical Reports Server (NTRS)

    Gooding, J. L. (Editor)

    1986-01-01

    Preliminary description and classifications of meteorites that were completed since publication of the February issue are contained. Most large (greater than 150 g) specimens (regardless of petrologic type) and all pebble sized (less than 150 g) specimens of special petrologic type are represented by separate descriptions. However, specimens of nonspecial petrologic type are listed only as single line entries. For convenience, new specimens are also recast by petrologic type. Each macroscopic description summarizes features that were visible to the eye at the time the meteorite was first examined. Classification is based on microscopic petrography and resonnaissance-level electron-probe microanalysis. The pairing list was updated.

  9. Enantiomer Ratios of Meteoritic Sugar Derivatives

    NASA Technical Reports Server (NTRS)

    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

  10. Zinc isotope anomalies. [In Allende meteorite

    SciTech Connect

    Volkening, J.; Papanastassiou, D.A. )

    1990-07-01

    The Zn isotope composition in refractory-element-rich inclusions of the Allende meteorite are determined. Typical inclusions contain normal Zn. A unique inclusion of the Allende meteorite shows an excess for Zn-66 of 16.7 + or - 3.7 eu (1 eu = 0.01 percent) and a deficit for Zn-70 of 21 + or - 13 eu. These results indicate the preservation of exotic components even for volatile elements in this inclusion. The observed excess Zn-66 correlates with excesses for the neutron-rich isotopes of Ca-48, Ti-50, Cr-54, and Fe-58 in the same inclusion. 32 refs.

  11. Computed tomographic analysis of meteorite inclusions.

    PubMed

    Arnold, J R; Testa, J P; Friedman, P J; Kambic, G X

    1983-01-28

    The discovery of isotopic anomalies in the calcium- and aluminum-rich inclusions of the Allende meteorite has improved our knowledge of the origin of the solar system. Inability to find more inclusions without destroying the meteorite has hampered further study. By using a fourth-generation computed tomographic scanner with modifications to the software only, the interior of heterogeneous materials such as Allende can be nondestructively probed. The regions of material with high and low atomic numbers are displayed quickly. The object can then be cut to obtain for analysis just the areas of interest.

  12. Chromium isotopic anomalies in the Allende meteorite

    NASA Technical Reports Server (NTRS)

    Papanastassiou, D. A.

    1986-01-01

    Abundances of the chromium isotopes in terrestrial and bulk meteorite samples are identical to 0.01 percent. However, Ca-Al-rich inclusions from the Allende meteorite show endemic isotopic anomalies in chromium which require at least three nucleosynthetic components. Large anomalies at Cr-54 in a special class of inclusions are correlated with large anomalies at Ca-48 and Ti-50 and provide strong support for a component reflecting neutron-rich nucleosynthesis at nuclear statistical equilibrium. This correlation suggests that materials from very near the core of an exploding massive star may be injected into the interstellar medium.

  13. The Petrography of Meteoritic Nano-Diamonds

    NASA Technical Reports Server (NTRS)

    Dai, Z. R.; Bradley, J. P.; Brownlee, D. E.; Joswiak, D. J.

    2003-01-01

    At least some meteoritic nanodiamonds are likely of presolar origin because of their association with anomalous Xe-HL and Te isotopic components indicative of a supernova (SN) origin. But the abundance of Xe is such that only approx. 1 in 10(exp 6) nano-diamonds contains a Xe atom, and the bulk C-13/C-12 composition of nano-diamond acid residues is chondritic (solar). Therefore, it is possible that a significant fraction of meteoritic nano-diamonds formed within the solar nebula. Nano-diamonds have recently been detected for the first time within the accretion discs of young stars by the Infrared Space Observatory (ISO). No comparable evidence of nanodiamonds in the interstellar medium has yet been found. We have identified nano-diamonds in acid etched thin-sections of meteorites, polar micrometeorites, and interplanetary dust particles (IDPs) with the goal of determining their distribution as a function of heliocentric distance. (It is assumed the meteorites and the polar micrometeorites are from asteroids at 2-4 AU and at least some of the IDPs are from comets at >50AU). We found that nano-diamonds are heterogeneously distributed throughout carbon-rich meteoritic materials (we identified them in some IDPs and not in others), and that their abundance may actually decrease with heliocentric distance, consistent with the hypothesis that some of them formed within the inner solar system and not in a presolar (SN) environment. In order to gain further insight about the origins of meteoritic nano-diamonds we are currently investigating their distribution in unetched thin-sections. We have examined a chondritic cluster IDP (U220GCA), fragments of the Tagish Lake (CM1) meteorite, and a SN graphite spherule (KE3d8) isolated from the Murchison (CM) meteorite. We selected U220GCA because its nano-diamond abundance (in acid etched thin-sections) appears to be as much as approx. 10X higher than in Murchison matrix, Tagish Lake because it has a higher reported nano

  14. Zinc isotope anomalies. [in Allende meteorite

    NASA Technical Reports Server (NTRS)

    Volkening, J.; Papanastassiou, D. A.

    1990-01-01

    The Zn isotope composition in refractory-element-rich inclusions of the Allende meteorite are determined. Typical inclusions contain normal Zn. A unique inclusion of the Allende meteorite shows an excess for Zn-66 of 16.7 + or - 3.7 eu (1 eu = 0.01 percent) and a deficit for Zn-70 of 21 + or - 13 eu. These results indicate the preservation of exotic components even for volatile elements in this inclusion. The observed excess Zn-66 correlates with excesses for the neutron-rich isotopes of Ca-48, Ti-50, Cr-54, and Fe-58 in the same inclusion.

  15. Comet and meteorite traditions of Aboriginal Australians

    NASA Astrophysics Data System (ADS)

    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.

  16. Meteorite Fractures and Scaling for Atmospheric Entry

    NASA Astrophysics Data System (ADS)

    Bryson, Kathryn L.; Ostrowski, Daniel R.

    2016-10-01

    We are attempting to understand the behavior of asteroids entering the atmosphere in order to help quantify the impact hazard. The strength of meteorites plays a critical role in determining the outcome of their impact events. Our objective is to scale fracture parameters in meteorites to their parent body.In this study over a thousand meteorite fragments in the Natural History Museums of Vienna and London (mostly hand-sized, some 40 or 50 cm across) were examined and fracture patterns in selected fragments were imaged. We identified six kinds of fracturing behavior. The density and length of the observed fractures were measured in hand specimens and thin sections. We assume that fracturing follows the Weibull distribution, where fractures are assumed to be randomly distributed through the target and the likelihood of encountering a fracture increases with distance. The images collected of the six fracture behaviors provide a two-dimensional view of the fractures. A relationship exists between the distributions of measured trace length and actual fracture size, where the slope of a log-log plot of trace length vs fracture density is proportional to α, the shape parameter. The value for α is unclear and a large range in α has been determined from light curve data. α can be used to scale strengths from the meteorite to the larger parent body.The majority of the meteorite fractures imaged displayed no particular sensitivity to meteorite texture. A value of α of 0.185 has been determined for a chondrite with a fracture pattern that shows no sensitivity to meteorite texture and has no point of origin. This study will continue to examine additional meteorites with similar fracture patterns along with the other 5 patterns to see if there is a correlation between fracture pattern and α. This may explain the variations in α determined from fireball data. Values of α will be used in models created by the Asteroid Threat Assessment Project to try to determine the

  17. Panspermia: Evidence from Astronomy to Meteorites

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, N. C.; Wallis, J.; Wallis, D. H.

    The theory of cometary panspermia is reviewed in relation to evidence from astronomy, biology, and recent studies of meteorites. The spectroscopic signatures in interstellar material within our galaxy and in external galaxies that have been known for many years most plausibly represent evidence for the detritus of life existing on a cosmic scale. Such spectral features discovered in galaxies of high redshift points to life arising at a very early stage in the history of the Universe. Evidence of fossils of microscopic life forms in meteorites that have been discussed over several decades, and augmented recently with new data, reaffirms the case for cometary panspermia.

  18. Panspermia: Evidence from Astronomy to Meteorites

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, N. C.; Wallis, J.; Wallis, D. H.

    2013-05-01

    The theory of cometary panspermia is reviewed in relation to evidence from astronomy, biology and recent studies of meteorites. The spectroscopic signatures in interstellar material within our galaxy and in external galaxies that have been known for many years most plausibly represent evidence for the detritus of life existing on a cosmic scale. Such spectral features discovered in galaxies of high redshift points to life arising at a very early stage in the history of the Universe. Evidence of fossils of microscopic life forms in meteorites that have been discussed over several decades, and augmented recently with new data, reaffirms the case for cometary panspermia.

  19. Fossil Diatoms in a New Carbonaceous Meteorite

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, N. C.; Wallis, J.; Wallis, D. H.; Samaranayake, Anil

    2013-01-01

    We report the discovery for the first time of diatom frustules in a carbonaceous meteorite that fell in the North Central Province of Sri Lanka on 29 December 2012. Contamination is excluded by the circumstance that the elemental abundances within the structures match closely with those of the surrounding matrix. There is also evidence of structures morphologically similar to red rain cells that may have contributed to the episode of red rain that followed within days of the meteorite fall. The new data on "fossil" diatoms provide strong evidence to support the theory of cometary panspermia.

  20. Solar proton produced neon in shergottite meteorites

    NASA Technical Reports Server (NTRS)

    Garrison, D. H.; Rao, M. N.; Bogard, D. D.

    1994-01-01

    Cosmogenic radionuclides produced by near-surface, nuclear interactions of energetic solar protons (approx. 10-100 MeV) were reported in several lunar rocks and a very small meteorites. We recently documented the existence and isotopic compositions of solar-produced (SCR) Ne in two lunar rocks. Here we present the first documented evidence for SCR Ne in a meteorite, ALH77005, which was reported to contain SCR radionuclides. Examination of literature data for other shergottites suggests that they may also contain a SCR Ne component. The existence of SCR Ne in shergottites may be related to a Martian origin.

  1. 7. Detail of balcony rail. August 1936. Joseph Hill, photographer, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Detail of balcony rail. August 1936. Joseph Hill, photographer, copied from small photo taken by survey member. - Jansonist Colony, Steeple Building, Main & Bishop Hill Streets, Bishop Hill, Henry County, IL

  2. 6. Detail of pilaster cap. Aug. 10, 1936. Joseph Hill, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail of pilaster cap. Aug. 10, 1936. Joseph Hill, photographer, copied from small photo taken by survey member. - Jansonist Colony, Steeple Building, Main & Bishop Hill Streets, Bishop Hill, Henry County, IL

  3. 3. West and south elevations. Joseph Hill, photographer, copied from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. West and south elevations. Joseph Hill, photographer, copied from photo lent by Evelyn S. Craig. August 1936. - Jansonist Colony, Steeple Building, Main & Bishop Hill Streets, Bishop Hill, Henry County, IL

  4. 1. Historic American Buildings Survey Joseph Hill, Photographer August 1936 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Joseph Hill, Photographer August 1936 FIRST ORIGINAL STORE AND POSTOFFICE, COPY OF AN EARLY PHOTOGRAPH. LENT BY EVELYN S. CRAIG - Jansonist Colony, Colony Store & Post Office, Main & Bishop Hill Streets, Bishop Hill, Henry County, IL

  5. The "House" in Half Hollow Hills

    ERIC Educational Resources Information Center

    Karnilow, Sheldon

    2006-01-01

    In this article, the author relates how he initiated a systemic improvement to Half Hollow Hills school district when he became its superintendent. He relates that although he came to Half Hollow Hills with a deep understanding of the models of systemic change, he did not bring with him a specific prescriptive plan for improvement. His plan for…

  6. Counseling Uses of the Hill Interaction Matrix.

    ERIC Educational Resources Information Center

    Boyd, Robert E.

    While the Hill Interaction Matrix was developed as a research instrument to assess interview process, it is also generally useful in any undertaking requiring the evaluation of verbal interaction and, hence, can be used as an aid in modifying communication in order to increase its therapeutic effect. The Hill Interaction Matrix with accompanying…

  7. Glaciated appalachian plateau: till shadows on hills.

    PubMed

    Coates, D R

    1966-06-17

    North slopes are twice as steep as south slopes on the hills of central New York. This asymmetry is caused by unequal till thickness-3.6 meters on north slopes and 27.6 meters on south slopes. Previous workers interpreted the hills as being of bedrock sculptured by glacial erosion, with till 0.9 to 3 meters thick.

  8. Leslie Pickney Hill's "Toussaint L'Ouverture."

    ERIC Educational Resources Information Center

    Ako, Edward O.

    1987-01-01

    In his 1928 play, the Harlem Renaissance writer Leslie Pickney Hill portrays Toussaint L'Ouverture, the leader of the Haitian slave rebellion, with historical accuracy. Hill's presentation was aimed at rehabilitating black pride, "A worthy literature reared upon authentic records of achievement is the present spiritual need of the race." (BJV)

  9. Colleges as Shining Cities on a Hill

    ERIC Educational Resources Information Center

    Townsend, Kathleen Kennedy

    2012-01-01

    In this article, the author proposes that the notion of America be reintroduced as the "shining city on a hill," that abiding image from American history. The image of the shining city on a hill captures the imagination because it reflects the abiding truth that people become fully human in society, not outside of it. People need one another to…

  10. Report on the Black Hills Alliance.

    ERIC Educational Resources Information Center

    Ryan, Joe

    1979-01-01

    A rally to save the Black Hills from coal- and uranium-greedy energy companies was held on July 6 and over 2,000 joined in a 15-mile walk on July 7 in Rapid City, South Dakota. The Black Hills Alliance, an Indian coalition concerned about energy development proposals in the Great Plains, sponsored the gathering. (NQ)

  11. Meteoritic Microfossils In Eltanin Impact Deposits

    NASA Astrophysics Data System (ADS)

    Kyte, F. T.; Wollenburg, J.; Gersonde, R.; Kuhn, G.

    2006-12-01

    Introduction: We report the unique occurrence of microfossils composed largely of meteoritic ejecta particles from the late Pliocene (2.5 Ma) Eltanin impact event. These deposits are unique, recording the only known km- sized asteroid impact into a deep-ocean (5 km) basin. First discovered as in Ir anomaly in sediment cores that were collected in 1965, the deposits contain mm-sized shock-melted asteroidal material, unmelted meteorite fragments (named the Eltanin meteorite), and trace impact spherules. Two oceanographic expeditions by the FS Polarstern in 1995 and 2001 explored 80,000 square km of the impact region, mapping the distribution of meteoritic ejecta, disturbance of seafloor sediments by the impact, and collected 20 new cores with impact deposits in the vicinity of the Freeden Seamounts (57.3S, 90.5W). Analyses of sediment cores show that the impact disrupted sediments on the ocean floor, redepositing them as a chaotic jumble of sediment fragments overlain by a sequence of laminated sands, silts and clays deposited from the water column. Overprinted on this is a pulse of meteoritic ejecta, likely transported ballistically, then settled through the water column. At some localities, meteoritic ejecta was as much as 5 to 50 kg per square meter. This is the most meteorite-rich locality known on Earth. Results: Two cores were taken in a basin near the top of the Freeden Seamounts at a water depth of 2.7 km. Sediments in this shallow basin are compositionally different than those at all other sites as they contain abundant calcareous microfossils. In deeper water sites (4 to 5 km depth), higher pressures and CO2 concentrations cause dissolution of calcite and sediments contain siliceous (opal) microfossils or are barren. An exception to this is a few sites in the immediate vicinity of the seamounts that contain calcareous sediments that flowed off the seamounts after being disturbed by the impact. At the top of the seamounts, sediments with meteoritic ejecta

  12. Solar Rossby Wave 'Hills' Identified As Supergranules

    NASA Technical Reports Server (NTRS)

    Williams, P. E.; Hathaway, David H.; Cuntz, M.

    2007-01-01

    We explore the nature of 'hills' observed on the solar surface which had previously been attributed to Rossby waves. We investigate the sol ar hills phenomenon by analyzing the output from a synthetic model ba sed solely on the observed solar photospheric convection spectrum. We show that the characteristics of these hills can be explained by the corrugation of the surface produced by the radial flows of the conve ction. The hills in our simulations are dominated by supergranules, a well-known component of solar convection. Rossby waves have been predicted to exist within the Sun and may play an important role in the d ynamics of the solar interior, including the Sun's differential rotat ion and magnetic dynamo. Our study suggests, however, that the hills observed at the solar limb do not confirm the existence of solar Ross by waves.

  13. Natural thermoluminescence of Antarctic meteorites and related studies

    NASA Technical Reports Server (NTRS)

    Benoit, Paul H.; Sears, Derek W. G.

    1998-01-01

    The natural thermoluminescence (TL) laboratory's primary purpose is to provide data on newly recovered Antarctic meteorites that can be included in discovery announcements and to investigate the scientific implications of the data. Natural TL levels of meteorites are indicators of recent thermal history and terrestrial history, and the data can be used to study the orbital/radiation history of groups of meteorites (e.g., H chondrites) or to study the processes leading to the concentration of meteorites at certain sites in Antarctica. An important application of these data is the identification of fragments, or "pairs" of meteorites produced during atmospheric passage or during terrestrial weathering. Thermoluminescence data are particularly useful for pairing within the most common meteorite classes, which typically exhibit very limited petrographic and chemical diversity. Although not originally part of the laboratory's objectives, TL data are also useful in the identification and classification of petrographically or mineralogically unusual meteorites, including unequilibrated ordinary chondrites and some basaltic achondrites. In support of its primary mission, the laboratory also engages in TL studies of modern falls, finds from hot deserts, and terrestrial analogs and conducts detailed studies of the TL properties of certain classes of meteorites. These studies include the measurement of TL profiles in meteorites, the determination of TL levels of finds from the Sahara and the Nullarbor region of Australia, and comparison of TL data to other indicators of irradiation or terrestrial history, such as cosmogenic noble gas and radionuclide abundances. Our current work can be divided into five subcategories, (a) TL survey of Antarctic meteorites, (b) pairing and field relations of Antarctic meteorites, (c) characterization of TL systematics of meteorites, (d) comparison of natural TL and other terrestrial age indicators for Antarctic meteorites, and for meteorites

  14. The multiple meteorite fall of Neuschwanstein: Circumstances of the event and meteorite search campaigns

    NASA Astrophysics Data System (ADS)

    Oberst, J.; Heinlein, D.; Köhler, U.; Spurný, P.

    2004-10-01

    A large meteorite fall in southern Germany on April 6, 2002 was captured by camera stations of the European Fireball Network (EN), which routinely monitors the night sky over central Europe. From analysis of the images, a prediction on the geographic location of the meteorite strewn field could be made. Following systematic ground searches in difficult high-mountain terrain, three fragments of a rare EL6 enstatite chondrite were recovered during search campaigns in the summers of 2002 and 2003. "Neuschwanstein" is the fourth meteorite fall in history that has been photographed by fireball networks and the fragments of which have been found subsequently. It is the first time since the beginning of the EN operation in the early sixties that the photographic observations have made a meteorite recovery possible.

  15. Antarctic meteorite newsletter. Volume 4: Number 1, February 1981: Antarctic meteorite descriptions, 1976, 1977, 1978, 1979

    NASA Technical Reports Server (NTRS)

    Stone, R.; Schwarz, C. M.; King, T. V. V.; Mason, B.; Bogard, D. D.; Gabel, E. M.

    1981-01-01

    This issue of the Newsletter is essentially a catalog of all antarctic meteorites in the collections of the Johnson Space Center Curation Facility and the Smithsonian except for 288 pebbles now being classed. It includes listings of all previously distributed data sheets plus a number of new ones for 1979. Indexes of samples include meteorite name/number, classification, and weathering category. Separate indexes list type 3 and 4 chondrites, all irons, all achondrites, and all carbonaceous chondrites.

  16. Layered Rocks in 'Columbia Hills'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This black-and-white image shows the first layered rocks scientists have seen close up in Gusev Crater, where NASA's Mars Exploration Rover Spirit landed Jan. 4, 2004. While Spirit's twin rover, Opportunity, reached the stadium-size Endurance Crater on the other side of Mars and began exploring its many layered outcrops in early May, Spirit traveled more than 3.5 kilometers (2.2 miles) to get to this layered bedrock in the 'Columbia Hills.' Scientists are planning to conduct a study of these rocks to determine if they are volcanic or sedimentary in origin, and if they have been chemically altered. Spirit's panoramic camera took this image on sol 217 (Aug. 13, 2004).

  17. Launch of martian meteorites in oblique impacts

    NASA Astrophysics Data System (ADS)

    Artemieva, Natalia; Ivanov, Boris

    2004-09-01

    A high-velocity oblique impact into the martian surface accelerates solid target material to escape velocity. A fraction of that material eventually falls as meteorites on Earth. For a long time they were called the SNC meteorites (Shergotty, Nakhla, and Chassigny). We study production of potential martian meteorites numerically within the frame of 3D hydrodynamic modeling. The ratio of the volume of escaping solid ejecta to projectile volume depends on the impact angle, impact velocity and the volatile content in the projectile and in the target. The size distribution of ejected fragments appears to be of crucial importance for the atmosphere-ejecta interaction in the case of a relatively small impact (with final crater size <3 km): 10-cm-sized particles are decelerated efficiently, while 30-50% of larger fragments could escape Mars. The results of numerical modeling are compared with shock metamorphic features in martian meteorites, their burial depth, and preatmospheric mass. Although it is impossible to accelerate ejected fragments to escape velocity without substantial compression (above 10 GPa), the maximum temperature increase in dunite (Chassigny) or ortopyroxenite (ALH84001) may be lower than 200 degree. This result is consistent with the observed chaotic magnetization of ALH84001. The probability of microbes' survival may be rather high even for the extreme conditions during the ejection process.

  18. The Meteoritical Bulletin, No. 80, 1996 July

    NASA Astrophysics Data System (ADS)

    Grossman, Jeffrey N.

    1996-07-01

    The Meteoritical Bulletin No. 80 lists data for 178 meteorites. Noteworthy are 3 HED meteorites (ALH 88102, Hammadah al Hamra (HaH) 059, and Monticello); 3 ureilites (HaH 064, HaH 126, and Dar al Gani (DaG) 084); 4 irons (Baygorria (IAB), Ste. Croix (IIIAB), Sargiin Gobi (IAB), and Tarahumara (IIE)); an unusual metal-rich meteorite (Vermillion); 8 carbonaceous chondrites (HaH 043 (C03), HaH 073 (C4), DaG 055 (C3) and 5 C03 chondrites (probably paired) from DaG); an R chondrite (DaG 013); and 6 unequilibrated ordinary chondrites (ALH 88105 (L3), Camel Donga 016 (L3), HaH 093 (LL3.9), HaH 096 (LL(L)3), Richfield (LL3.7), and Sarir Quattusah (LL(L)3)). Three recent falls of ordinary chondrites (Coleman (LL5), St. Robert (H5), and Tsukuba (H5-6)) are described.

  19. THE NITROGEN ISOTOPIC COMPOSITION OF METEORITIC HCN

    SciTech Connect

    Pizzarello, Sandra

    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.

  20. Dangerous Near-Earth Asteroids and Meteorites

    NASA Astrophysics Data System (ADS)

    Mickaelian, A. M.; Grigoryan, A. E.

    2015-07-01

    The problem of Near-Earth Objects (NEOs; Astreoids and Meteorites) is discussed. To have an understanding on the probablity of encounters with such objects, one may use two different approaches: 1) historical, based on the statistics of existing large meteorite craters on the Earth, estimation of the source meteorites size and the age of these craters to derive the frequency of encounters with a given size of meteorites and 2) astronomical, based on the study and cataloging of all medium-size and large bodies in the Earth's neighbourhood and their orbits to estimate the probability, angles and other parameters of encounters. Therefore, we discuss both aspects and give our present knowledge on both phenomena. Though dangerous NEOs are one of the main source for cosmic catastrophes, we also focus on other possible dangers, such as even slight changes of Solar irradiance or Earth's orbit, change of Moon's impact on Earth, Solar flares or other manifestations of Solar activity, transit of comets (with impact on Earth's atmosphere), global climate change, dilution of Earth's atmosphere, damage of ozone layer, explosion of nearby Supernovae, and even an attack by extraterrestrial intelligence.

  1. Origin of Excess 176Hf in Meteorites

    NASA Astrophysics Data System (ADS)

    Thrane, Kristine; Connelly, James N.; Bizzarro, Martin; Meyer, Bradley S.; The, Lih-Sin

    2010-07-01

    After considerable controversy regarding the 176Lu decay constant (λ176Lu), there is now widespread agreement that (1.867 ± 0.008) × 10-11 yr-1 as confirmed by various terrestrial objects and a 4557 Myr meteorite is correct. This leaves the 176Hf excesses that are correlated with Lu/Hf elemental ratios in meteorites older than ~4.56 Ga meteorites unresolved. We attribute 176Hf excess in older meteorites to an accelerated decay of 176Lu caused by excitation of the long-lived 176Lu ground state to a short-lived 176m Lu isomer. The energy needed to cause this transition is ascribed to a post-crystallization spray of cosmic rays accelerated by nearby supernova(e) that occurred after 4564.5 Ma. The majority of these cosmic rays are estimated to penetrate accreted material down to 10-20 m, whereas a small fraction penetrate as deep as 100-200 m, predicting decreased excesses of 176Hf with depth of burial at the time of the irradiation event.

  2. The Germanium Dichotomy in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Humayun, M.; Yang, S.; Righter, K.; Zanda, B.; Hewins, R. H.

    2016-01-01

    Germanium is a moderately volatile and siderophile element that follows silicon in its compatibility during partial melting of planetary mantles. Despite its obvious usefulness in planetary geochemistry germanium is not analyzed routinely, with there being only three prior studies reporting germanium abundances in Martian meteorites. The broad range (1-3 ppm) observed in Martian igneous rocks is in stark contrast to the narrow range of germanium observed in terrestrial basalts (1.5 plus or minus 0.1 ppm). The germanium data from these studies indicates that nakhlites contain 2-3 ppm germanium, while shergottites contain approximately 1 ppm germanium, a dichotomy with important implications for core formation models. There have been no reliable germanium abundances on chassignites. The ancient meteoritic breccia, NWA 7533 (and paired meteorites) contains numerous clasts, some pristine and some impact melt rocks, that are being studied individually. Because germanium is depleted in the Martian crust relative to chondritic impactors, it has proven useful as an indicator of meteoritic contamination of impact melt clasts in NWA 7533. The germanium/silicon ratio can be applied to minerals that might not partition nickel and iridium, like feldspars. We report germanium in minerals from the 3 known chassignites, 2 nakhlites and 5 shergottites by LAICP- MS using a method optimized for precise germanium analysis.

  3. Determination of Meteorite Porosity Using Liquid Nitrogen

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  5. Novel SLC16A2 mutations in patients with Allan-Herndon-Dudley syndrome.

    PubMed

    Shimojima, Keiko; Maruyama, Koichi; Kikuchi, Masahiro; Imai, Ayako; Inoue, Ken; Yamamoto, Toshiyuki

    2016-08-01

    Allan-Herndon-Dudley syndrome (AHDS) is an X-linked disorder caused by impaired thyroid hormone transporter. Patients with AHDS usually exhibit severe motor developmental delay, delayed myelination of the brain white matter, and elevated T3 levels in thyroid tests. Neurological examination of two patients with neurodevelopmental delay revealed generalized hypotonia, and not paresis, as the main neurological finding. Nystagmus and dyskinesia were not observed. Brain magnetic resonance imaging demonstrated delayed myelination in early childhood in both patients. Nevertheless, matured myelination was observed at 6 years of age in one patient. Although the key finding for AHDS is elevated free T3, one of the patients showed a normal T3 level in childhood, misleading the diagnosis of AHDS. Genetic analysis revealed two novel SLC16A2 mutations, p.(Gly122Val) and p.(Gly221Ser), confirming the AHDS diagnosis. These results indicate that AHDS diagnosis is sometimes challenging owing to clinical variability among patients. PMID:27672545

  6. Origin of igneous meteorites and differentiated asteroids

    NASA Astrophysics Data System (ADS)

    Scott, E.; Goldstein, J.; Asphaug, E.; Bottke, W.; Moskovitz, N.; Keil, K.

    2014-07-01

    Introduction: Igneously formed meteorites and asteroids provide major challenges to our understanding of the formation and evolution of the asteroid belt. The numbers and types of differentiated meteorites and non-chondritic asteroids appear to be incompatible with an origin by fragmentation of numerous Vesta-like bodies by hypervelocity impacts in the asteroid belt over 4 Gyr. We lack asteroids and achondrites from the olivine-rich mantles of the parent bodies of the 12 groups of iron meteorites and the ˜70 ungrouped irons, the 2 groups of pallasites and the 4--6 ungrouped pallasites. We lack mantle and core samples from the parent asteroids of the basaltic achondrites that do not come from Vesta, viz., angrites and the ungrouped eucrites like NWA 011 and Ibitira. How could core samples have been extracted from numerous differentiated bodies when Vesta's basaltic crust was preserved? Where is the missing Psyche family of differentiated asteroids including the complementary mantle and crustal asteroids [1]? Why are meteorites derived from far more differentiated parent bodies than chondritic parent bodies even though C and S class chondritic asteroids dominate the asteroid belt? New paradigm. Our studies of meteorites, impact modeling, and dynamical studies suggest a new paradigm in which differentiated asteroids accreted at 1--2 au less than 2 Myr after CAI formation [2]. They were rapidly melted by 26Al and disrupted by hit-and-run impacts [3] while still molten or semi-molten when planetary embryos were accreting. Metallic Fe-Ni bodies derived from core material cooled rapidly with little or no silicate insulation less than 4 Myr after CAI formation [4]. Fragments of differentiated planetesimals were subsequently tossed into the asteroid belt. Meteorite evidence for early disruption of differentiated asteroids. If iron meteorites were samples of Fe-Ni cores of bodies that cooled slowly inside silicate mantles over ˜50--100 Myr, irons from each core would have

  7. Meteorite and meteoroid: New comprehensive definitions

    USGS Publications Warehouse

    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

  8. Cobbles and Meteorites at Meridiani Planum, Mars.

    NASA Astrophysics Data System (ADS)

    Fleischer, Iris; Klingelhöfer, Göstar; Schroeder, Christian; Ashley, James

    The Mars Exploration Rover Opportunity landed on the plains of Meridiani Planum in January 2004 and has since covered a distance of more than 19 kilometers. The Meridiani plains are covered with basaltic sand, with frequent exposures of sulfate rich outcrop rock and a lag de-posit of hematite-rich spherules [1, 2]. Occasionally, Opportunity also encountered loose rocks scattered across the surface. To date, about a dozen of these "cobbles" with dimensions of a few centimeters have been analysed with Opportunity's contact instruments, providing information about elemental chemistry (Alpha Particle X-ray spectrometer, APXS), iron mineralogy and oxidation states (Müssbauer spectrometer, MB) and texture (Microscopic Imager, MI). Based on their chemistry and mineralogy, cobbles can be divided into three distinct groups. The first group comprises light toned fragments of the sulfate-rich bedrock, which are chemically and mineralogically indistinguishable from other outcrop rock. Among the remaining, dark-toned cobbles, two separate groups can be distinguished, referred to as "Barberton group", have high Ni and contain Fe-Ni metal phases and troilite, pointing to a meteoritic origin. They are prob-ably paired and may be mesosiderite fragments [3, 4]. "Arkansas group" cobbles appear to be related to soil and to Meridiani outcrop. They have brecciated textures, possibly pointing to an impact-related origin during which local bedrock and soil may have been mixed [5]. The groups were named after the first specimen of each group encountered by Opportunity. In addition, Opportunity encountered four iron meteorites. The first , "Heat Shield Rock", was encountered in January 2005 and officially recognized as the first iron meteorite on the martian surface with the name "Meridiani Planum" after the location of its find [3, 6, 7]. Three other iron meteorites were encountered between July and October 2009, separated by 10 km from Heat Shield Rock but less than 1 km from each other

  9. Chiral Biomarkers and Microfossils in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.

    2010-01-01

    Homochirality of the biomolecules (D-sugars of DNA and RNA and L-amino acids of proteins) is a fundamental property of all life on Earth. Abiotic mechanisms yield racemic mixtures (D/L=1) of chiral molecules and after the death of an organism, the enantiopure chiral biomolecules slowly racemize. Several independent investigators have now established that the amino acids present in CI1 and CM2 carbonaceous meteorites have a moderate to strong excess of the L-enantiomer. Stable isotope data have established that these amino acids are both indigenous and extraterrestrial. Carbonaceous meteorites also contain many other strong chemical biomarkers including purines and pyrimidines (nitrogen heterocycles of nucleic acids); pristine and phytane (components of the chlorophyll pigment) and morphological biomarkers (microfossils of filamentous cyanobacteria). Energy dispersive X-ray Spectroscopy (EDS) analysis reveals that nitrogen is below the detectability level in most of the meteorite filaments as well as in Cambrian Trilobites and filaments of 2.7 Gya Archaean cyanobacteria from Karelia. The deficiency of nitrogen in the filaments and the total absence of sugars, of twelve of the life-critical protein amino acids, and two of the nucleobases of DNA and RNA provide clear and convincing evidence that these filaments are not modern biological contaminants. This paper reviews the chiral, chemical biomarkers morphological biomarkers and microfossils in carbonaceous meteorites. This paper reviews chiral and morphological biomarkers and discusses the missing nitrogen, sugars, protein amino acids, and nucleobases as ?bio-discriminators? that exclude modern biological contaminants as a possible explanation for the permineralized cyanobacterial filaments found in the meteorites.

  10. The 10Be contents of SNC meteorites

    NASA Technical Reports Server (NTRS)

    Pal, D. K.; Tuniz, C.; Moniot, R. K.; Savin, W.; Vajda, S.; Kruse, T.; Herzog, G. F.

    1986-01-01

    Several authors have explored the possibility that the Shergottites, Nakhlites, and Chassigny (SNC) came from Mars. The spallogenic gas contents of the SNC meteorites have been used to: constrain the sizes of the SNC's during the last few million years; to establish groupings independent of the geochemical ones; and to estimate the likelihood of certain entries in the catalog of all conceivable passages from Mars to Earth. The particular shielding dependence of Be-10 makes the isotope a good probe of the irradiation conditions experienced by the SNC meteorites. The Be-10 contents of nine members of the group were measured using the technique of accelerator mass spectrometry. The Be-10 contents of Nakhla, Governador Valadares, Chassigny, and probably Lafayette, about 20 dpm/kg, exceed the values expected from irradiation of the surface of a large body. The Be-10 data therfore do not support scenario III of Bogard et al., one in which most of the Be-10 in the SNC meteorites would have formed on the Martian surface; they resemble rather the Be-10 contents found in many ordinary chondrites subjected to 4 Pi exposures. The uncertainties of the Be-10 contents lead to appreciable errors in the Be-10 ages, t(1) = -1/lambda ln(1 Be-10/Be-10). Nonetheless, the Be-10 ages are consistent with the Ne-21 ages calculated assuming conventional, small-body production rates and short terrestrial ages for the finds. It is believed that this concordance strengthens the case for at least 3 different irradiation ages for the SNC meteorites. Given the similar half-thicknesses of the Be-10 and Ne-21 production rates, the ratios of the Be-10 and Ne-21 contents do not appear consistent with common ages for any of the groups. In view of the general agreement between the Be-10 and Ne-21 ages it does not seem useful at this time to construct multiple-stage irradiation histories for the SNC meteorites.

  11. Terrestrial microbes in martian and chondritic meteorites

    NASA Astrophysics Data System (ADS)

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

    2007-08-01

    Good extraterrestrial analogs for microbiology are SNC meteorites as Mars analogs, and chondrites as early planet analogs. Chondrites and SNCs are used to trace processes in the early solar system and on Mars. Yet, questions about terrestrial contamination and its effects on the isotopic, chemical and mineral characteristics often arise. A wide biodiversity was found in 21 chondrites of groups CR, CV, CK, CO from ANSMET, CI and CM Falls, and 8 SNCs. Studies documented the alteration of meteorites by weathering and biology [1]-[6], and during aqueous extraction for oxygen isotopic analysis [7], visible biofilms grew in the meteorite solutions in days. To assess biological isotopic and chemical impacts, cultures were incubated 11 months and analyzed by PCR. The sequences for 2 isolates from EET 87770 and Leoville were of a good quality with long sequence reads. In EET 87770, the closest matches were in the genus Microbacterium. Soil and plant isolates were close relatives by sequence comparison. Bacillus, a common soil bacterial genus, grew in a Leoville culture. All SNCs exhibited biological activity measured independently by LAL but only 1 colony was successfully cultured from grains of the SNC Los Angeles. Isotopic analyses of samples with various amounts of microbial contamination could help quantified isotopic impact of microbes on protoplanetary chemistry in these rocks. References: [1] Gounelle, M.& Zolensky M. (2001) LPS XXXII, Abstract #999. [2] Fries, M. et al. (2005) Meteoritical Society Meeting 68, Abstract # 5201. [3] Burckle, L. H. & Delaney, J. S (1999) Meteoritics & Planet. Sci., 32, 475. [4] Whitby, C. et al. (2000) LPS XXXI, Abstract #1732. [5] Tyra M. et al., (2007) Geochim. Cosmochim. Acta, 71, 782 [6] Toporski, J. & Steele A., (2007) Astrobiology, 7, 389 [7]Airieau, S. et al (2005) Geochim. Cosmochim. Acta, 69, 4166.

  12. Search for fullerenes in stone meteorites

    NASA Astrophysics Data System (ADS)

    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.

  13. Chiral biomarkers and microfossils in carbonaceous meteorites

    NASA Astrophysics Data System (ADS)

    Hoover, Richard B.

    2010-09-01

    Homochirality of the biomolecules (D-sugars of DNA and RNA and L-amino acids of proteins) is a fundamental property of all life on Earth. Abiotic mechanisms yield racemic mixtures (D/L=1) of chiral molecules and after the death of an organism, the enantiopure chiral biomolecules slowly racemize. Several independent investigators have now established that the amino acids present in CI1 and CM2 carbonaceous meteorites have a moderate to strong excess of the L-enantiomer. Stable isotope data have established that these amino acids are both indigenous and extraterrestrial. Carbonaceous meteorites also contain many other strong chemical biomarkers including purines and pyrimidines (nitrogen heterocycles of nucleic acids); pristine and phytane (components of the chlorophyll pigment) and morphological biomarkers (microfossils of filamentous cyanobacteria). Energy dispersive X-ray Spectroscopy (EDS) analysis reveals that nitrogen is below the detectability level in most of the meteorite filaments as well as in Cambrian Trilobites and filaments of 2.7 Gya Archaean cyanobacteria from Karelia. The deficiency of nitrogen in the filaments and the total absence of sugars, of twelve of the life-critical protein amino acids, and two of the nucleobases of DNA and RNA provide clear and convincing evidence that these filaments are not modern biological contaminants. This paper reviews the chiral, chemical biomarkers morphological biomarkers and microfossils in carbonaceous meteorites. This paper reviews chiral and morphological biomarkers and discusses the missing nitrogen, sugars, protein amino acids, and nucleobases as "bio-discriminators" that exclude modern biological contaminants as a possible explanation for the permineralized cyanobacterial filaments found in the meteorites.

  14. Tracing meteorite source regions through asteroid spectroscopy

    NASA Astrophysics Data System (ADS)

    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

  15. Descent from the Summit of 'Husband Hill'

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for Descent from the Summit of 'Husband Hill' (QTVR)

    In late November 2005 while descending 'Husband Hill,' NASA's Mars Exploration Rover Spirit took the most detailed panorama so far of the 'Inner Basin,' the rover's next target destination. Spirit acquired the 405 individual images that make up this 360-degree view of the surrounding terrain using five different filters on the panoramic camera. The rover took the images on Martian days, or sols, 672 to 677 (Nov. 23 to 28, 2005 -- the Thanksgiving holiday weekend).

    This image is an approximately true-color rendering using camera's 750-, 530-, and 430-nanometer filters. Seams between individual frames have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

    'Home Plate,' a bright, semi-circular feature scientists hope to investigate, is harder to discern in this image than in earlier views taken from higher up the hill. Spirit acquired this more oblique view, known as the 'Seminole panorama,' from about halfway down the south flank of Husband Hill, 50 meters (164 feet) or so below the summit. Near the center of the panorama, on the horizon, are 'McCool Hill' and 'Ramon Hill,' named, like Husband Hill, in honor of the fallen astronauts of the space shuttle Columbia. Husband Hill is visible behind the rover, on the right and left sides of the panorama. An arc of rover tracks made while avoiding obstacles and getting into position to examine rock outcrops can be traced over a long distance by zooming in to explore the panorama in greater detail.

    Spirit is now significantly farther downhill toward the center of this panorama, en route to Home Plate and other enigmatic soils and outcrop rocks in the quest to uncover the history of Gusev Crater and the 'Columbia Hills.'

  16. Meteorite and meteoroid: New comprehensive definitions

    NASA Astrophysics Data System (ADS)

    Rubin, Alan E.; Grossman, Jeffrey 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-μm to 1-m-size natural solid object moving in interplanetary space. A micrometeoroid is a meteoroid 10μm to 2mm in size. A meteorite is a natural, solid object larger than 10μm 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 10μm and 2mm 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

  17. Hill-Climbing Attacks and Robust Online Signature Verification Algorithm against Hill-Climbing Attacks

    NASA Astrophysics Data System (ADS)

    Muramatsu, Daigo

    Attacks using hill-climbing methods have been reported as a vulnerability of biometric authentication systems. In this paper, we propose a robust online signature verification algorithm against such attacks. Specifically, the attack considered in this paper is a hill-climbing forged data attack. Artificial forgeries are generated offline by using the hill-climbing method, and the forgeries are input to a target system to be attacked. In this paper, we analyze the menace of hill-climbing forged data attacks using six types of hill-climbing forged data and propose a robust algorithm by incorporating the hill-climbing method into an online signature verification algorithm. Experiments to evaluate the proposed system were performed using a public online signature database. The proposed algorithm showed improved performance against this kind of attack.

  18. Cosmic-ray Exposure Ages of Meteorites

    NASA Astrophysics Data System (ADS)

    Herzog, G. F.

    2003-12-01

    The classic idea of a cosmic-ray exposure (CRE) age for a meteorite is based on a simple but useful picture of meteorite evolution, the one-stage irradiation model. The precursor rock starts out on a parent body, buried under a mantle of material many meters thick that screens out cosmic rays. At a time ti, a collision excavates a precursor rock - a "meteoroid." The newly liberated meteoroid, now fully exposed to cosmic rays, orbits the Sun until a time tf, when it strikes the Earth, where the overlying blanket of air (and possibly of water or ice) again shuts out almost all cosmic rays (cf. Masarik and Reedy, 1995). The quantity tf-ti is called the CRE age, t. To obtain the CRE age of a meteorite, we measure the concentrations in it of one or more cosmogenic nuclides (Table 1), which are nuclides that cosmic rays produce by inducing nuclear reactions. Many shorter-lived radionuclides excluded from Table 1 such as 22Na (t1/2=2.6 yr) and 60Co (t1/2=5.27 yr) can also furnish valuable information, but can be measured only in meteorites that fell within the last few half-lives of those nuclides (see, e.g., Leya et al. (2001) and references therein). Table 1. Cosmogenic nuclides used for calculating exposure ages NuclideHalf-lifea (Myr) Radionuclides 14C0.005730 59Ni0.076 41Ca0.1034 81Kr0.229 36Cl0.301 26Al0.717 10Be1.51 53Mn3.74 129I15.7 Stable nuclides 3He 21Ne 38Ar 83Kr 126Xe a http://www2.bnl.gov/ton. CRE ages have implications for several interrelated questions. From how many different parent bodies do meteorites come? How well do meteorites represent the population of the asteroid belt? How many distinct collisions on each parent body have created the known meteorites of each type? How often do asteroids collide? How big and how energetic were the collisions that produced meteoroids? What factors control the CRE age of a meteorite and how do meteoroid orbits evolve through time? We will touch on these questions below as we examine the data.By 1975, the CRE ages of

  19. Analysis of Chiral Carboxylic Acids in Meteorites

    NASA Technical Reports Server (NTRS)

    Burton, A. S.; Elsila, J. E.; Hein, J. E.; Aponte, J. C.; Parker, E. T.; Glavin, D. P.; Dworkin, J. P.

    2015-01-01

    Homochirality of amino acids in proteins and sugars in DNA and RNA is a critical feature of life on Earth. In the absence of a chiral driving force, however, reactions leading to the synthesis of amino acids and sugars result in racemic mixtures. It is currently unknown whether homochirality was necessary for the origins of life or if it was a product of early life. The observation of enantiomeric excesses of certain amino acids of extraterrestrial origins in meteorites provides evidence to support the hypothesis that there was a mechanism for the preferential synthesis or destruction of a particular amino acid enantiomer [e.g., 1-3]. The cause of the observed chiral excesses is un-clear, although at least in the case of the amino acid isovaline, the degree of aqueous alteration that occurred on the meteorite parent body is correlated to the isovaline L-enantiomeric excess [3, 4]. This suggests that chiral symmetry is broken and/or amplified within the meteorite parent bodies. Besides amino acids, there have been only a few reports of other meteoritic compounds found in enantiomeric excess: sugars and sugar acids [5, 6] and the hydroxy acid lactic acid [7]. Determining whether or not additional types of molecules in meteorites are also present in enantiomeric excesses of extraterrestrial information will provide insights into mechanisms for breaking chiral symmetry. Though the previous measurements (e.g., enantiomeric composition of lactic acid [7], and chiral carboxylic acids [8]) were made by gas chromatography-mass spectrometry, the potential for increased sensitivity of liquid chromatography-mass spectrometry (LC-MS) analyses is important because for many meteorite samples, only small sample masses are available for study. Furthermore, at least in the case of amino acids, many of the largest amino acid enantiomeric excesses were observed in samples that contained lower abundances (tens of ppb) of a given amino acid enantiomer. In the present work, we describe

  20. Meteorite heat capacities: Results to date

    NASA Astrophysics Data System (ADS)

    Consolmagno, G.; Macke, R.; Britt, D.

    2014-07-01

    Heat capacity is an essential thermal property for modeling asteroid internal metamorphism or differentiation, and dynamical effects like YORP or Yarkovsky perturbations. We have developed a rapid, inexpensive, and non-destructive method for measuring the heat capacity of meteorites at low temperature [1]. A sample is introduced into a dewar of liquid nitrogen and an electronic scale measures the amount of nitrogen boiled away as the sample is cooled from the room temperature to the liquid nitrogen temperature; given the heat of vaporization of liquid nitrogen, one can then calculate the heat lost from the sample during the cooling process. Note that heat capacity in this temperature range is a strong function of temperature, but this functional relation is essentially the same for all materials; the values we determine are equivalent to the heat capacity of the sample at 175 K. To correct for systematic errors, samples of laboratory-grade quartz are measured along with the meteorite samples. To date, more than 70 samples of more than 50 different meteorites have been measured in this way, including ordinary chondrites [1], irons [2], basaltic achondrites [3], and a limited number of carbonaceous chondrites [1]. In general, one can draw a number of important conclusions from these results. First, the heat capacity of a meteorite is a function of its mineral composition, independent of shock, metamorphism, or other physical state. Second, given this relation, heat capacity can be strongly altered by terrestrial weathering. Third, the measurement of heat capacity in small (less than 1 g) samples as done typically by commercial systems runs a serious risk of giving misleading results for samples that are heterogeneous on scales of tens of grams or more. Finally, we demonstrate that heat capacity is a useful tool for determining and classifying a sample, especially if used in conjunction with other intrinsic variables such as grain density and magnetic susceptibility

  1. Interstellar organic globules in meteorites and comets

    NASA Astrophysics Data System (ADS)

    Messenger, Scott; Nakamura-Messenger, Keiko; Keller, Lindsay

    Organic matter in primitive meteorites and interplanetary dust particles (IDPs) is often enriched in D/H and 15N/14N relative to terrestrial values [1-3] due to preservation of interstellar cold molecular cloud material [1]. Some meteorites and IDPs contain micrometer-size inclusions with extreme H and N isotopic anomalies [2-4], possibly due to preserved primordial organic grains. In the Tagish Lake meteorite the main carriers of these anomalies are sub-micrometer, hollow organic globules [5]. Similar objects have been observed in extracts of other chondritic meteorites, but little is known about their N and H isotopic compositions [6-8]. We have measured the H, C, and N isotopic compositions of organic globules in the Bells CM2 carbonaceous chondrite meteorite, NASA Stardust (comet Wild-2) mission samples, and in ‘cometary' IDPs. High-resolution TEM imaging and EELS show that the globules consist of structurally amorphous carbon lacking long range order or development of graphite-like domains. In almost all cases the organic globules have strong enrichments in D/H and 15N/14N. These isotopic anomalies likely resulted from low temperature ( 10 K) chemical reactions in a cold molecular cloud or at the outer regions of the protosolar nebula. These results show that microscopic organic grains were widespread constituents of the protoplanetary disk. Microscopic organic globules may thus have been a common form of prebiotic organic matter delivered to the early Earth by comets and meteorites. References: [1] Messenger S. and Walker R.M. in Astrophysical Implications of the Laboratory Study of Presolar Materials (1997), p.545. [2] Messenger S. (2000) Nature 404, 968. [3] Busemann H. et al. (2006), Science 312, 727. [4] Floss C. et al. (2004) Science 303, 1355. [5] Nakamura-Messenger K. et al. (2006) Science, 314, 1439. [6] Claus G. and Nagy B., (1961) Nature 192, 594 [7] Aoki T., Akai J., Makino K. (2003) Int Symp.Evol. of Solar System Materials 5 [8] Garvie L

  2. Processing of Antarctic Meteorites at NASA/Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Satterwhite, C. E.; McBridge, K. M.; Harrington, R. S.; Righter, K.

    2011-01-01

    Since the beginning of the Antarctic Search for Meteorites (ANSMET) program in 1976, over 18,000 meteorites have been processed in the Meteorite Processing Lab at Johnson Space Center in Houston, TX. The first step is to renumber the meteorites from field tag number to generic number and log all the information into the meteorite database. Initial processing involves drying the meteorites in a nitrogen glove box for 24 to 48 hours, photographing, measuring, weighing and writing an exterior description. Next step is to break the meteorite and obtain a good representative sample that will be sent to the Smithsonian institution for classification. Once all the processing is done and the meteorites have been classified, the information is published in the Antarctic meteorite newsletter. The newsletter is published twice yearly and is sent electronically to researchers around the world and is also available on line. Researchers are asked to fill out a request form. The bulk of this paper relates to the researcher's request for meteorite samples.

  3. Identifying meteorite source regions through near-Earth object spectroscopy

    NASA Astrophysics Data System (ADS)

    Thomas, Cristina A.; Binzel, Richard P.

    2010-02-01

    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 important 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 possible links 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-μm and 2-μm 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 four classes: H, L, LL and HED. For each NEO spectrum, we assign a set of probabilities for it being related to each of these four 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. While the ν6 resonance dominates the delivery for all four meteorite classes, an excess (significant at the 2.1-sigma level) source region signature is found for the H chondrites through the 3:1 mean motion resonance. This results suggest an H chondrite source with a higher than average delivery preference through the 3:1 resonance. A 3:1 resonance H chondrite source region is consistent with the short cosmic ray exposure ages known for H chondrites.

  4. Inside Beacon Hill: Bertrand Russell as Schoolmaster.

    ERIC Educational Resources Information Center

    Jespersen, Shirley

    1987-01-01

    The author describes the life and theories of Bertrand Russell, founder of Beacon Hill School. Russell's educational theories centered on the personal autonomy of the student and democratization of the learning process. (CH)

  5. A perspective on Capitol Hill

    NASA Astrophysics Data System (ADS)

    Hodges, Carroll Ann

    As the AGU Congressional Science Fellow for 1980-1981, I had a unique opportunity to witness the federal engine in action—a remarkable piece of machinery. The American Association for the Advancement of Science organized an excellent orientation program, introducing our class of science fellows (about 30) to the kinds of options available for a year's tenure on Capitol Hill. These include affiliation with a congressman's or senator's staff or with one of the hundred or so standing, select, or joint committees and subcommittees. I arranged to join the personal staff of Congressman Jim Santini (D, Nev.), largely because of his demonstrated interest in Department of Interior affairs in general and the minerals industry in particular. The position of fellow provides no guarantee of work in one's areas of expertise or inclination, however, and I found that my staff assignments included topics ranging from wild horses to peanut subsidies. My principal task involved evaluation of the Air Force proposal to deploy the MX missile in Nevada and the consequent impact of that incredible scheme on the physical and economic environments of the state and the nation, including effects on minerals exploration. I had not expected to become conversant with missile technology, but the exercise provided quite an education.

  6. The Igwisi Hills extrusive 'kimberlites'

    NASA Technical Reports Server (NTRS)

    Reid, A. M.; Donaldson, C. H.; Dawson, J. B.; Brown, R. W.; Ridley, W. I.

    1975-01-01

    The petrography and mineral chemistry of volcanic rocks from the Igwisi Hills in Tanzania are discussed. There is considerable evidence to suggest that the Igwisi rocks are extrusive kimberlites: a two-component nature with high P-T minerals in a low P-T matrix; the presence of chrome pyrope, Al enstatite, chrome diopside, chromite and olivine; a highly oxidized, volatile-rich matrix with serpentine, calcite, magnetite, perovskite; high Sr, Zr, and Nb contents; occurrence in a narrow isolated vent within a stable shield area. The Igwisi rocks differ from kimberlite in the lack of magnesian ilmenite, the scarcity of matrix phlogopite, and the overall low alkali content. They apparently contain material from phlogopite-bearing garnet peridotites with a primary mineral assemblage indicative of equilibrium at upper mantle temperatures and pressures. This primary assemblage was brought rapidly to the surface in a gas-charged, carbonate-rich fluid. Rapid upward transport, extrusion, and rapid cooling have tended to prevent reaction between inclusions and the carbonate-rich matrix that might otherwise have yielded a more typical kimberlite.

  7. Oblique View of Columbia Hills

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Annotated Version

    This perspective view looking toward the northeast shows part of the Columbia Hills range inside Gusev Crater. At the center is the winter campaign site of NASA's Mars Exploration Rover Spirit.

    On its 805th Martian day, or sol, (April 8, 2006), Spirit was parked on a slope tilting 11 degrees to the north to maximize sunlight on the solar panels during the southern winter season. Science observations were formulated to take advantage of the long time during which the rover was parked. The plan focused on two tasks: tracking atmospheric and surface dynamics by periodically surveying the surface and atmosphere; and extensively examining surrounding terrains, rocks and soils using the panoramic camera and the miniature thermal emission spectrometer, coupled with long duration measurements using the alpha particle X-ray and Moessbauer spectrometers of rock and soil targets. For reference, the feature known as 'Home Plate' is approximately 90 meters (295 feet) wide.

    An image from Mars Global Surveyor's Mars Orbital Camera, catalogued as E03_00012 and courtesy Malin Space Science Systems, was used as the base image for this figure. The perspective was generated using elevation data generated from analyses of the camera's stereo images by the U.S. Geological Survey, Flagstaff, Ariz.

  8. Comparison of lunar rocks and meteorites: Implications to histories of the moon and parent meteorite bodies

    NASA Technical Reports Server (NTRS)

    Prinz, M.; Fodor, R. V.; Keil, K.

    1974-01-01

    A number of similarities between lunar and meteoritic rocks are reported and suggest that the comparison is essential for a clear understanding of meteorites as probes of the early history of the solar systems: (1) Monomict and polymict breccias occur in lunar rocks, as well as in achondritic and chondritic meteorites, having resulted from complex and repeated impact processes. (2) Chondrules are present in lunar, as well as in a few achondritic and most chondritic meteorites. It is pointed out that because chondrules may form in several different ways and in different environments, a distinction between the different modes of origin and an estimate of their relative abundance is important if their significance as sources of information on the early history of the solar system is to be clearly understood. (3) Lithic fragments are very useful in attempts to understand the pre- and post-impact history of lunar and meteoritic breccias. They vary from little modified (relative to the apparent original texture), to partly or completely melted and recrystallized lithic fragments.

  9. Rochechouart meteorite crater - Identification of projectile

    NASA Technical Reports Server (NTRS)

    Janssens, M.-J.; Hertogen, J.; Takahashi, H.; Anders, E.; Lambert, P.

    1977-01-01

    Ten samples from the 20-km Rochechouart crater in France have been analyzed for the siderophile elements Ir, Os, Re, Au, Pd, Ni, and Ge by radiochemical neutron activation analysis. The up to 1000-fold enrichment of siderophiles correlates with shock effects, increasing in the following order from least to greatest: basement rocks, glass-free breccias, glassy breccias, impact melts. The abundance pattern of the meteorite was determined from interelement correlations. Several samples fell off the correlation lines, presumably due to recrystallization and weathering of impact glasses during the approximately 165-m.y. age of the crater. The most reliable diagnostic elements were Os, Ir, Ni, and Pd; their abundance ratios suggest that the Rochechouart meteorite was a IIA iron.

  10. The Chelyabinsk meteorite fall: Geochemistry and Mineralogy

    NASA Astrophysics Data System (ADS)

    Galimov, Eric

    Just after the Chelyabinsk meteorite fall, the Vernadsky Institute and the Committee on Meteorites of the Russian Academy of Sciences have organized an expedition to collect fragments of the meteorite shower. The collected material has been comprehensively studied for textural characteristics, mineral chemistry, major and trace elements, nuclear tracks, and isotopic composition. The texture, mineral chemistry, and major element contents indicate that the Chelyabinsk meteorite belongs to the LL5group of ordinary chondrites and was affected by a moderate degree of shock metamorphism (stage S4). The majority (2/3) of the collected stones is composed from a light lithology with a typical chondritic texture. Chondrules ( 63%) are readily delineated and set within a fragmental matrix. The chondrule glass is devitrified. The main phases are olivine and orthopyroxene. Olivine has mosaicism and planar fractures. Rare grains of augite and clinobronzite are present. Small and rare feldspar grains show undulutory extinction, planar deformation features, and are partly isotropic. Troilite (4 vol.%) and FeNi metal (1.3 vol.%) occur as irregularly shaped grains. Accessories are chromite, ilmenite, Cl-apatite, and native Cu. A significant portion (1/3) of the stones consists of a dark impact melt breccia containing mineral and chondrule fragments. Feldspar of the lithology is well developed and practically isotropic. No high-pressure phases were found in the impact melt. There are black colored thin shock veins in both light and dark lithologies. Olivine Fa 27.9±0.35, N=22; ortopyroxene Fs 22.8±0.79, Wo 1.30±0.26, N=17; feldspar Ab 86; chromite Fe/Fe+Mg=0.90, Cr/Cr+Al=0.85 (at.). Major element composition of the light lithology (wt%): Si=18.3, Ti=0.053, Al=1.12, Cr=0.40, Fe=19.8, Mn=0.26, Ca=1.43, Na=0.74, K=0.11, P=0.10, Ni=1.06, Co=0.046, S=1.7. The dark lithology has almost the same composition but it is distinctly higher in Ag, Pb, Bi. Sm-Nd isotopic characteristics

  11. Mineralogy and chemistry of planets and meteorites

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The data collection and the interpretation with respect to the mineralogy of meteoritic and terrestrial samples are summarized. The key conclusion is that the Moon underwent a series of melting episodes with complex crystal-liquid differentiation. It was not possible to determine whether the Moon melted completely or only partially. The stage is now set for a systematical geochemical and geophysical survey of the Moon. Emphasis was moved to meteorites in order to sort out their interrelationships from the viewpoint of mineral chemistry. Several parent bodies are needed for the achondrites with different chemical properties. Exploration of Mars is required to test ideas based on the possible assignment of shergottites, nakhlites and chassignite to this planet. Early rocks on the Earth have properties consistent with a heavy bombardment and strong volcanic activity prior to 4 billion years ago.

  12. Volatile compounds in shergottite and nakhlite meteorites

    NASA Technical Reports Server (NTRS)

    Gooding, James L.; Aggrey, Kwesi E.; Muenow, David W.

    1990-01-01

    Since discovery of apparent carbonate carbon in Nakhla, significant evidence has accumulated for occurrence of volatile compounds in shergotties and nakhlites. Results are presented from a study of volatile compounds in three shergottites, one nakhlite, and three eucrite control samples. Shergotties ALHA77005, EETA79001, and Shergotty, and the nakhlite Nakhla, all contain oxidized sulfur (sulfate) of preterrestrial origin; sulfur oxidation is most complete in EETA79001/Lith-C. Significant bulk carbonate was confirmed in Nakhla and trace carbonate was substantiated for EETA79001, all of which appears to be preterrestrial in origin. Chlorine covaries with oxidized sulfur, whereas carbonate and sulfate are inversely related. These volatile compounds were probably formed in a highly oxidizing, aqueous environment sometime in the late stage histories of the rocks that are now represented as meteorites. They are consistent with the hypothesis that shergottite and nakhlite meteorites originated on Mars and that Mars has supported aqueous geochemistry during its history.

  13. Reduced Martian Carbon: Evidence from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, SImon J.; Pillinger, COlin T.; Wright, Ian P.; Verchovsky, A. P.

    2010-01-01

    Identification of indigenous reduced carbon species on Mars has been a challenge since the first hypotheses about life on Mars were proposed. Ranging from the early astronomical measurements to analyses of samples from the Martian surface in the form of Martian meteorites. The first direct attempt to analyze the carbon species on the surface was in 1976 with the Viking GC-MS in-situ experiment which gave inconclusive results at two sites on Mars [1]. With the recognition in 1983 that samples of the Martian surface were already present on Earth in the form of Martian meteorites by Bogard and Johnson [2] new opportunities became available for direct study of Mars's samples in te rlraesbtrioalratories. Carbon isotopic compositional information suggested a reduced carbon component was present in the Martian meteorites [3-5]. Polycyclic aromatic hydrocarbons associated with carbonate globules in ALH84001 were later identified [6,7]. Jull et al [8] noted that an insoluble component was present within Nakhla and more than 75% of its C lacked any 14C, which is modern-day carbon contaminant. This carbon fraction was believed to be either indigenous (i..e. Martian) or ancient meteoritic carbon phase. Within the fractures of Nakhla and ALH84001, Fisk et al [9,10] identified reduced carbon-enriched areas. Gibson et al. [11] using a combination of NanoSIMS, Focused Electron microscopy, Laser Raman Spectroscopy and Stepped-Combustion Static Mass Spectrometry analyses the presence of possible indigenous reduced carbon components within the 1.3 Ga old Nakhla.

  14. Large Meteorite Impacts and Planetary Evolution

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The present volume of abstracts of conference papers discusses topics associated with the role of meteorite impacts on the Earth, the moon, and Titan. Particular attention is given to the description of the impact damage and the description of the actual craters. Attention is also given to the Sudbury structure, and the Chicxulub crater. Mineralogical, geophysical, petrographic, seismic and image data are described and discussed.

  15. Nature of Reduced Carbon in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    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

  16. Fractionation and Accretion of Meteorite Parent Bodies

    NASA Technical Reports Server (NTRS)

    Weidenschilling, Stuart J.

    2005-01-01

    Senior Scientist Stuart J. Weidenschilling presents his final administrative report for the research program on which he was the Principal Investigator. The research program resulted in the following publications: 1) Particle-gas dynamics and primary accretion. J. N. Cuzzi and S. J . Weidenschilling. To appear in Meteorites and the Early Solar System 11 (D. Lauretta et a]., Eds.), Univ. Arizona Press. 2005; 2) Timescales of the solar protoplanetary disk. S. Russell, L. Hartmann, J . N. Cuzzi, A. Krot, M. Gounelle and S. J. Weidenschilling. To appear in Meteorites and the Early Solar System II (D. Lauretta et al., Eds.), Univ. Arizona Press, 2005; 3) Nebula evolution of thermally processed solids: Reconciling astrophysical models and chondritic meteorites. J. N. Cuzzi, F. J. Ciesla, M. I. Petaev, A. N. Krot, E. R. D. Scott and S . J. Weidenschilling. To appear in Chondrites and the Protoplanetary Disk (A. Krot et a]., Eds.), ASP Conference Series, 2005; 4) Possible chondrule formation in planetesimal bow shocks: Physical processes in the near vicinity of the planetesimal. L. L. Hood, F. J. Ciesla and S. J. Weidenschilling. To appear in Chondrites and the Protoplanetary Disk (A. Krot et al., Eds.), ASP Conference Series, 2005; 5) From icy grains to comets. In Comets II (M. Festou et al., Eds.), Univ. Arizona Press, pp. 97- 104, 2005; 6) Evaluating planetesimal bow shocks as sites for chondrule formation. F. J . Ciesla, L. L. Hood and S. J. Weidenschilling. Meteoritics & Planetary Science 39, 1809-1 821, 2004; and 7) Radial drift of particles in the solar nebula: Implications for planetesimal formation. Icarus 165, 438-442, 2003.

  17. Phosphates and Carbon in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Mojzsis, Stephen J.

    2000-01-01

    This paper proposes tests for exobiological examination of samples prior to obtaining martian rocks of known provenance via future sample-return missions. If we assume that all of the secondary minerals in martian meteorite ET79001 were indeed cogenetic and originate from Mars, we list conclusions that can be drawn that are of exobiological interest. This work serves as a preamble for the subsequent work listed below.

  18. Mechanical Properties of Fe-Ni Meteorites

    NASA Astrophysics Data System (ADS)

    Roberta, Mulford; El Dasher, B.

    2010-10-01

    Iron-nickel meteorites exhibit a unique lamellar microstructure, Widmanstatten patterns, consisting of small regions with steep-iron-nickel composition gradients.1,2 The microstructure arises as a result of extremely slow cooling in a planetary core or other large mass. Mechanical properties of these structures have been investigated using microindentation, x-ray fluorescence, and EBSD. Observation of local mechanical properties in these highly structured materials supplements bulk measurements, which can exhibit large variation in dynamic properties, even within a single sample. 3 Accurate mechanical properties for meteorites may enable better modeling of planetary cores, the likely origin of these objects. Appropriate values for strength are important in impact and crater modeling and in understanding the consequences of observed impacts on planetary crusts. Previous studies of the mechanical properties of a typical iron-nickel meteorite, a Diablo Canyon specimen, indicated that the strength of the composite was higher by almost an order of magnitude than values obtained from laboratory-prepared specimens.4 This was ascribed to the extreme work-hardening evident in the EBSD measurements. This particular specimen exhibited only residual Widmanstatten structures, and may have been heated and deformed during its traverse of the atmosphere. Additional specimens from the Canyon Diablo fall (type IAB, coarse octahedrite) and examples from the Muonionalusta meteorite and Gibeon fall ( both IVA, fine octahedrite), have been examined to establish a range of error on the previously measured yield, to determine the extent to which deformation upon re-entry contributes to yield, and to establish the degree to which the strength varies as a function of microstructure. 1. A. Christiansen, et.al., Physica Scripta, 29 94-96 (1984.) 2. Goldstein and Ogilvie, Geochim Cosmochim Acta, 29 893-925 (1965.) 3. M. D. Furnish, M.B. Boslough, G.T. Gray II, and J.L. Remo, Int. J. Impact Eng

  19. Cosmochemistry and Mineralogy of Primitive Meteorites

    NASA Technical Reports Server (NTRS)

    Buseck, Peter R.

    2003-01-01

    We have produced significant research results during the grant period. These have been reported in five papers published in Geochimica et Cosmochimica Acta and Meteoritics and Planetary Science and several others are in review. We also presented 17 abstracted talks at professional meetings. The citations are given in section 2, and abstracts of the papers are provided in section 3. The full papers are available on request.

  20. Acritarchs in carbonaceous meteorites and terrestrial rocks

    NASA Astrophysics Data System (ADS)

    Rozanov, Alexei Y.; Hoover, Richard B.

    2013-10-01

    Acritarchs are a group of organic-walled, acid-resistant microfossils of uncertain or unknown origin. Some are thought to represent the cysts or resting stages of unicellular protists (possibly dinoflagellates), chrysophytes (green algae) or other planktonic eukaryotic algae. Acritarchs are found throughout the geologic column extending back as far at 3.2 Ga. The presence of large sphaeromorphs in the Archaean provides evidence that the eukaryotic lineage extends much farther back in time than previously thought possible. Acritarchs are abundant in the Paleoproterozoic shales (1.9-1.6 Ga) of the former Soviet Union and they have been extensively used for the investigation of Proterozoic and Paleozoic biostratigraphy and paleoenvironmental parameters. Scanning Electron Microscope studies have revealed the fossilized remains of organic-walled microfossils of unknown origin and exhibiting characteristics of acritarchs in a variety of carbonaceous meteorites. In many cases, these remains are black or brown in color and have Carbon/Oxygen ratios suggesting they have been diagenetically converted into kerogen. It is not feasible that the fossilized remains of organicwalled microfossils such as acritarchs represent biological contaminant that invaded and became embedded in the rock matrix of carbonaceous meteorites within the short time periods of their residence on Earth. Consequently, these groups of microfossils are considered to provide an additional line for the existence of indigenous extraterrestrial microbial remains in meteorites. This paper presents a brief review of acritarchs in terrestrial rocks and provides images of a number of similar morphotypes of uncertain origin found in freshly fractured samples of carbonaceous meteorites.

  1. EVIDENCE FOR COMET STORMS IN METEORITE AGES

    SciTech Connect

    Perlmutter, S.; Muller, R.A.

    1987-10-01

    Clustering of cosmic-ray exposure ages of H chondritic meteorites occurs at 7 {+-} 3 and 30 {+-} 6 Myr ago. There is independent evidence that comet storms have occurred at the same times, based on the fossil record of family and genus extinctions, impact craters and glass, and geomagnetic reversals. We suggest that H chondrites were formed by the impact of shower comets on asteroids. The duration of the most recent comet shower was {le} 4 Myr, in agreement with storm theory.

  2. The meteorite of Ensisheim - 1492 to 1992

    NASA Technical Reports Server (NTRS)

    Marvin, Ursula B.

    1992-01-01

    The history of the 127 kg stony meteorite that fell at Ensisheim in Alsace on November 7, 1492 is reviewed along with people's responses to it through the 500 years since the fall. Stories surrounding the various theories of the time are shown by poems, religious tracts, graphic illustrations and paintings, and broadsheets issued over various periods in the context of politics. Consideration is given to the Ensisheim Stone as analyzed in Paris and Berlin.

  3. Moessbauer spectroscopy and scanning electron microscopy of the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Brown, Christopher L.; Oliver, Frederick W.; Hammond, Ernest C., Jr.

    1989-01-01

    Meteorites provide a wealth of information about the solar system's formation, since they have similar building blocks as the Earth's crust but have been virtually unaltered since their formation. Some stony meteorites contain minerals and silicate inclusions, called chondrules, in the matrix. Utilizing Moessbauer spectroscopy, we identified minerals in the Murchison meteorite, a carbonaceous chondritic meteorite, by the gamma ray resonance lines observed. Absorption patterns of the spectra were found due to the minerals olivine and phyllosilicate. We used a scanning electron microscope to describe the structure of the chondrules in the Murchison meteorite. The chondrules were found to be deformed due to weathering of the meteorite. Diameters varied in size from 0.2 to 0.5 mm. Further enhancement of the microscopic imagery using a digital image processor was used to describe the physical characteristics of the inclusions.

  4. Antarctic Meteorite Newsletter, Volume 11, Number 2, August 1988

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Presented are classifications and descriptions of a large number of meteorites which include the last samples from the 1984 collection and the first samples from the 1987 collection. There is a particularly good selection of meteorites of special petrologic type in the 1987 collection. The achondrites include aubrites, ureilites, howardites, eucrites, and a diogenite. The howardites are particularly notable because of their size and previous scarcity in the Antarctic collection. Noteworthy among the 7 irons and 3 mesosiderities are 2 anamolous irons and 2 large mesosiderites. The carbonaceous chondrites include good suites of C2 and C4 meteorites, and 2 highly equilibrated carbonaceous chondrites tentatively identified as C5 and C6 meteorites. Also included are surveys of numerous meteorites for Al-26 and thermoluminescence. These studies provide information on the thermal and radiation histories of the meteorites and can be used as measures of their terrestrial ages.

  5. Cosmic-ray exposure records and origins of meteorites

    NASA Technical Reports Server (NTRS)

    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.

  6. Harvesting meteorites in the Omani desert: implications for astrobiology

    NASA Astrophysics Data System (ADS)

    Hofmann, Beda A.; Gnos, Edwin; Al-Kathriri, Ali

    2004-03-01

    Meteorites will remain the most accessible, most diverse and most abundant source of extraterrestrial materials for many years to come. New sources of large numbers of meteorites allow the recovery of rare types particularly relevant for astrobiology, including Martian and Lunar samples. Oman has become an important source of meteorites only since 1999. Conditions for search and recovery are particularly favourable in many areas here because of an abundance of flat, light-colored, sand- and vegetation-free surfaces. During search expeditions carried out in the central deserts of Oman in 2001-2003 large numbers of meteorites, including a Martian and a Lunar sample, were recovered. The mass of recovered meteorites is 1334 kg, corresponding to approximately 150 to 200 fall events. We aim to classify all recovered specimens and study pairing and weathering effects. Our expeditions demonstrate the possibility to recover meteorite samples with astrobiological relevance with modest investments of finances and manpower.

  7. The resonant orbit of the Lost City meteorite

    NASA Technical Reports Server (NTRS)

    Williams, J. G.

    1975-01-01

    An integration of the long-period perturbations of Jupiter and Saturn on the orbit of the Lost City meteorite shows that the average nodal rate of the meteorite was nearly the same as the nodal rates of Jupiter and Saturn. This near equality of rates led to a large resonant variation in the inclination of the meteorite's orbit with a period on the order of 1 million years. The resonance makes the orbital evolution too sensitive to the deficiencies of the perturbation calculations and to the values of the elements at impact to allow definitive calculations. It is shown that an orbit similar to the meteorite's orbit can spend approximately 88% of its time with an eccentricity too small to allow for intersections with the earth's orbit. The ordinary cosmic ray exposure age of the Lost City meteorite does not suggest that its collisional lifetime was unusual, but the role of resonances in determining the lifetime of typical meteorites is unknown.

  8. Hardness of kamacite and shock histories of 119 meteorites.

    NASA Technical Reports Server (NTRS)

    Jain, A. V.; Gordon, R. B.; Lipschutz, M. E.

    1972-01-01

    Use of metallographic and X-ray diffraction techniques to study the shock histories of 119 iron and stony-iron meteorites, and measurement of the hardness of kamacite in these specimens and in artificially shocked-unannealed and annealed meteorite specimens. Shock increases kamacite hardness, but complications introduced by other physical and chemical properties of meteorites limit its utility as a shock indicator. About 50% of the meteorites studied show evidence for preterrestrial shock loading to pressures of greater than or equal to 130 kb, and 40% have not been shocked to such high pressures. The remaining meteorites have been heat-altered in such a way that their shock histories cannot be determined explicitly. These results, together with those obtained previously, indicate that the plurality, if not the majority, of all iron and stony-iron meteorites sampled by the earth were shocked to pressures of greater than or equal to 130 kb during preterrestrial collisions between asteroidal-sized objects.

  9. Organic compounds in meteorites and their origins

    NASA Technical Reports Server (NTRS)

    Hayatsu, R.; Anders, E.

    1981-01-01

    The current investigation represents an extensively updated version of a review conducted by Anders et al. (1973). The investigation takes into account the literature through mid-1980. It is pointed out that Type 1 carbonaceous chondrites (C1) contain 6% of their cosmic complement of carbon, mainly in the form of organic matter. Most authors now agree that this material represents primitive prebiotic matter. The principal questions remaining are what abiotic processes formed the organic matter, and to what extent these processes took place in locales other than the solar nebula, such as interstellar clouds or meteorite parent bodes. The problem is approached in three stages. It is attempted to reconstruct the physical conditions during condensation from the clues contained in the inorganic matrix of the meteorite. The condensation behavior of carbon under these conditions is determined on the basis of thermodynamic calculations. Model experiments on the condensation of carbon are performed, and the synthesized compounds are compared with those actually found in meteorites.

  10. Samarium-neodymium evolution of meteorites

    NASA Technical Reports Server (NTRS)

    Prinzhofer, A.; Papanastassiou, D. A.; Wasserburg, G. J.

    1992-01-01

    The feasibility of using Sm-147 and Sm-146 as chronometers was investigated using Sm-Nd data obtained on three meteorites: Ibitira, Morristown, and Acapulco. The results of isotope analyses demonstrate the presence of in situ decay of short-lived Sm-146 in these meteorites with initial abundances of Sm-146/Sm-144 between 0.009 and 0.007 in different meteorites. Precisely defined Sm-147/Nd-143 internal isochrons were obtained yielding ages equal to 4.46 +/-0.02 AE for Ibitira, 4.47 +/-0.02 AE for Morristown, and 4.60 +/-0.03 AE for Acapulco. However, detailed examination of the coupled Sm-147/Nd-143 and Sm-146/Nd-142 parent-daughter systematics and of initial Nd-143/Nd-144 values indicated the presence of inconsistencies in the data in spite of the precise isochrons, indicating the need for care in the interpretation of the parent-daughter systematics, even when they appear well behaved.

  11. Multiple Cosmic Sources for Meteorite Macromolecules?

    PubMed Central

    Watson, Jonathan S.; Meredith, William; Love, Gordon D.; Gilmour, Iain; Snape, Colin E.

    2015-01-01

    Abstract The major organic component in carbonaceous meteorites is an organic macromolecular material. The Murchison macromolecular material comprises aromatic units connected by aliphatic and heteroatom-containing linkages or occluded within the wider structure. The macromolecular material source environment remains elusive. Traditionally, attempts to determine source have strived to identify a single environment. Here, we apply a highly efficient hydrogenolysis method to liberate units from the macromolecular material and use mass spectrometric techniques to determine their chemical structures and individual stable carbon isotope ratios. We confirm that the macromolecular material comprises a labile fraction with small aromatic units enriched in 13C and a refractory fraction made up of large aromatic units depleted in 13C. Our findings suggest that the macromolecular material may be derived from at least two separate environments. Compound-specific carbon isotope trends for aromatic compounds with carbon number may reflect mixing of the two sources. The story of the quantitatively dominant macromolecular material in meteorites appears to be made up of more than one chapter. Key Words: Abiotic organic synthesis—Carbonaceous chondrite—Cosmochemistry—Meteorites. Astrobiology 15, 779–786. PMID:26418568

  12. Magnetic remanence in the Murchison meteorite

    NASA Astrophysics Data System (ADS)

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

    2003-03-01

    The Murchison meteorite is a carbonaceous chondrite containing a small amount of chondrules, various inclusions, and matrix with occasional porphyroblasts of olivine and/or pyroxene. It also contains amino acids that may have served as the necessary components for the origin of life. Magnetic analyses of Murchison identify an ultrasoft magnetic component due to superparamagnetism as a significant part of the magnetic remanence. The rest of the remanence may be due to electric discharge in the form of lightning bolts that may have formed the amino acids. The level of magnetic remanence does not support this possibility and points to a minimum ambient field of the remanence acquisition. We support our observation by showing that normalized mineral magnetic acquisition properties establish a calibration curve suitable for rough paleofield determination. When using this approach, 1­2% of the natural remanence left in terrestrial rocks with TRM and/or CRM determines the geomagnetic field intensity irrespective of grain size or type of magnetic mineral (with the exception of hematite). The same method is applied to the Murchison meteorite where the measured meteorite remanence determines the paleofield minimum intensity of 200­2000 nT during and/or after the formation of the parent body.

  13. De Magnete et Meteorite: Cosmically Motivated Materials

    SciTech Connect

    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.

  14. The breakup of a meteorite parent body and the delivery of meteorites to earth

    NASA Technical Reports Server (NTRS)

    Benoit, Paul H.; Sears, D. W. G.

    1992-01-01

    Whether many of the 10,000 meteorites collected in the Antarctic are unlike those falling elsewhere is contentious. The Antarctic H chondrites, one of the major classes of stony meteorites, include a number of individuals with higher induced thermoluminescence peak temperatures than observed among non-Antarctic H chondrites. The proportion of such individuals decreases with the mean terrestrial age of the meteorites at the various ice fields. These H chondrites have cosmic-ray exposure ages of about 8 million years, experienced little cosmic-ray shielding, and suffered rapid postmetamorphic cooling. Breakup of the H chondrite parent body, 8 million years ago, may have produced two types of material with different size distributions and thermal histories. The smaller objects reached earth more rapidly through more rapid orbital evolution.

  15. Isotopic composition of tellurium in the Abee meteorite

    SciTech Connect

    Smith, C.L.; De Laeter, J.R.

    1986-03-01

    The research of Smith et al. (1978) and Oliver et al. (1981) on the Abee meteorite's possible negative tellurium anomaly is extended. Two sets of measurements of the tellurium isotopic composition of Abee are reported, and the meteoritic data are compared with a terrestrial tellurium standard. No isotopic anomalies can be distinguished within the error limits. However, further work on the isotopic composition of Te in residues from the Allende meteorite need to be pursued by accurate mass spectrometric analysis. 23 references

  16. Identifying Meteorite Source Regions Through Near-Earth Object Spectroscopy

    NASA Astrophysics Data System (ADS)

    Thomas, Cristina A.; Binzel, R. P.

    2007-10-01

    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 most likely gives the best representation of meteorite source bodies. By linking meteorites to NEOs, and linking NEOs to their most likely main-belt source regions, we seek to gain insight into the original solar system sources 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 (NEOs). We utilize meteorite spectra from the Reflectance Experiment Laboratory (RELAB) database and NEO data from the SpeX instrument on the NASA IRTF. Using the Modified Gaussian Model (MGM) (Sunshine et al. 1993, JGR 98, 9075) as a mathematical tool (with no mineralogy interpretation), 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). We fit the continuum as a linear function in wavenumber space. We choose to include the geometric center of the band in this study in order to examine the asymmetry of the bands. Using this numerical data we can examine the differences of 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 classes, yielding probability distributions for our NEO data set being related to H, L, LL, and HED meteorites. Our meteorite correlation distribution is then convolved with an NEO source region model (Bottke et al. 2002, Icarus 156, 399) to shed light on connections between these meteorite classes and their asteroid belt origins.

  17. What Lunar Meteorites Tell Us About the Lunar Highlands Crust

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    The first meteorite to be found1 that was eventually (1984) recognized to have originated from the Moon is Yamato 791197. The find date, November 20, 1979, was four days after the end of the first Conference on the Lunar Highland Crust. Since then, >75 other lunar meteorites have been found, and these meteorites provide information about the lunar highlands that was not known from studies of the Apollo and Luna samples

  18. Petrography and Geochemistry of Lunar Meteorite Miller Range 13317

    NASA Technical Reports Server (NTRS)

    Zeigler, R. A.; Korotev, R. L.

    2016-01-01

    Miller Range (MIL) 13317 is a 32-g lunar meteorite collected during the 2013-2014 ANSMET (Antarctic Search for Meteorites) field season. It was initially described as having 25% black fusion crust covering a light- to dark-grey matrix, with numerous clasts ranging in size up to 1 cm; it was tenta-tively classified as a lunar anorthositic breccia. Here we present the petrography and geochemistry of MIL 13317, and examine possible pairing relationships with previously described lunar meteorites.

  19. Drought in the Black Hills

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Annotated Color-Coded Map

    Despite good rainfall and record-setting snowstorms in the spring of 2005, most of northeastern Wyoming, the Black Hills, and western South Dakota remain in the midst of a severe drought. This set of images and maps from NASA's Multi-angle Imaging SpectroRadiometer (MISR) contrast the appearance of the Black Hills region of northwestern South Dakota on July 12, 2000 (left column), with views acquired four years later, on July 14, 2004 (right column). The natural-color images along the top are from MISR's nadir (downward-looking) camera. The browning that appears in 2004 compared with 2000 indicates that the vigor of green vegetation was significantly diminished in 2004.

    The color-coded maps (along the bottom) provide a quantitative measurement of the sunlight reflected from these surfaces, and the loss of sunlight-absorbing vegetation between the 2000 and 2004 dates. As the vegetation faded with the drought, the albedo at the surface increased. Albedo measures the fraction of incident sunlight that is reflected by a surface, and can vary between zero (if all the incident sunlight is absorbed and none is reflected) and one (if all sunlight is reflected and none is absorbed). Dense forest has a low albedo; bright desert, snow and clouds, have a high albedo. Here, albedo is provided for the wavelengths of sunlight that plants use for photosynthesis (400 - 700 nanometers). This measurement is known as the albedo for Photosynthetically Active Radiation (PAR). Surfaces with greater absorption of PAR appear here in blue hues, whereas surfaces with lower absorption appear as green, yellow, orange or red. Black pixels indicate areas where albedo could not be derived, usually due to the presence of clouds. In July 2004, low albedo areas (blue pixels) are notably reduced in extent, and higher albedo areas (yellow, orange and red pixels) have increased.

    Because incoming sunlight is

  20. Bunker Hill Sediment Characterization Study

    SciTech Connect

    Neal A. Yancey; Debby F. Bruhn

    2009-12-01

    The long history of mineral extraction in the Coeur d’Alene Basin has left a legacy of heavy metal laden mine tailings that have accumulated along the Coeur d’Alene River and its tributaries (U.S. Environmental Protection Agency, 2001; Barton, 2002). Silver, lead and zinc were the primary metals of economic interest in the area, but the ores contained other elements that have become environmental hazards including zinc, cadmium, lead, arsenic, nickel, and copper. The metals have contaminated the water and sediments of Lake Coeur d’Alene, and continue to be transported downstream to Spokane Washington via the Spokane River. In 1983, the EPA listed the Bunker Hill Mining and Metallurgical Complex on the National Priorities List. Since that time, many of the most contaminated areas have been stabilized or isolated, however metal contaminants continue to migrate through the basin. Designation as a Superfund site causes significant problems for the economically depressed communities in the area. Identification of primary sources of contamination can help set priorities for cleanup and cleanup options, which can include source removal, water treatment or no action depending on knowledge about the mobility of contaminants relative to water flow. The mobility of contaminant mobility under natural or engineered conditions depends on multiple factors including the physical and chemical state (or speciation) of metals and the range of processes, some of which can be seasonal, that cause mobilization of metals. As a result, it is particularly important to understand metal speciation (National Research Council, 2005) and the link between speciation and the rates of metal migration and the impact of natural or engineered variations in flow, biological activity or water chemistry.

  1. Preliminary Results on Magnetic Mineralogy and Elemental Composition of Meteorites from Geological Museum of Kazan University

    NASA Astrophysics Data System (ADS)

    Kuzina, D. M.; Nurgaliev, D. K.; Gareev, B. I.; Batalin, G. A.; Silantev, V. V.

    2016-08-01

    Thermomagnetic analysis (magnetic mineralogy) and Micro X-ray Fluorescence analysis (mapping) were made for collection of meteorites. As a result we have elements distribution on surface of meteorites and Fe-Ni presence in meteorites.

  2. The Orgueil meteorite: 150 years of history

    NASA Astrophysics Data System (ADS)

    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

  3. Samarium-neodymium evolution of meteorites

    SciTech Connect

    Prinzhofer, A.; Papanastassiou, D.A.; Wasserburg, G.J. )

    1992-02-01

    The authors have obtained Sm-Nd data on two differentiated meteorites, Ibitira, a eucrite with distinct basaltic texture and with evidence of crystallization; and Morristown, a group 3A mesosiderite; as well as on Acapulco, an unclassified meteorite with chondritic chemical composition and a highly recrystallized texture. They have demonstrated the presence of in situ decay of short-lived {sup 146}Sm in these meteorites with initial abundance of {sup 146}Sm/{sup 144}Sm from 0.009 to 0.007 for the different meteorites. Precisely defined {sup 147}Sm-{sup 143}Nd internal isochrons were obtained yielding ages of 4.60 {+-} 0.03 AE for Acapulco, 4.47 {+-} 0.02 AE for Morristown, and 4.46 {+-} 0.02 AE for Ibitira. The corresponding initial {sup 143}Nd/{sup 144}Nd values obtained were 0.2 {+-} 0.9, 2.1 {+-} 0.7, and 1.6 {+-} 0.8 {var epsilon}u (epsilon units). Detailed consideration of the coupled {sup 147}Sm-{sup 143}Nd and {sup 146}Sm-{sup 142}Nd systematics and of the elevated initial {sup 143}Nd/{sup 144}Nd values indicates the presence of inconsistencies in the data for the two Sm-Nd parent-daughter pairs in spiteof the precise isochrons. The authors present a model which provides an interpretation of the paired Sm-Nd systematics in terms of an impulsive disturbance. The results indicate that three meteorites studied are relatively ancient objects, formed within the first 50 to 100 m.y. of the solar system, by planetary differentiation and impact processes, and were subjected to late metamorphism. The time of late metamorphism is substantially younger than 4.4 AE and possibly as recent as {approximately}3.9 AE. This metamorphism has resulted in partial, very limited reequilibration between plagioclase and phosphate, resulting in the observed shifts in initial {sup 143}Nd/{sup 144}Nd, Sm-Nd model ages, and the {sup 142}Nd/{sup 144}Nd abundances, but preserving the major temporal structures of early original formation and later disturbances.

  4. The Kaidun Meteorite: Where Did It Come From?

    NASA Technical Reports Server (NTRS)

    Ivanov, Andrei; Zolensky, Michael

    2003-01-01

    The Kaidun meteorite, which fell on 3.12.1980 at lat. 15 deg N, long. 48.3 deg E, holds a special place in the world meteorite collection. Kaidun is characterized by an unprecedentedly wide variety of meteorite material in its makeup. The high degree of variability in this meteorite s material is evidenced by the richness of its mineral composition - nearly 60 minerals and mineral phases have been identified in Kaidun, including several never before found in nature, such as florenskiite FeTiP, the first known phosphide of a lithophilic element.

  5. Lunar and Planetary Science XXXV: Isotopes in Meteorites

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session"Isotopes in Meteorites" consisted of the following presentations:The Common Property of Isotopic Anomalies in Meteorites; Revised Production Rates for 22Na and 54Mn in Meteorites Using Cross Sections Measured for Neutron-induced Reactions; Modeling of 14C and 10Be Production Rates in Meteorites and Lunar Samples; Investigating Xenon Isotopic Fractionation During Rayleigh-type Distillation; The Mean Life Squared Relationship for Abundances of Extinct Radioactivities; and Magnesium Isotopic Fractionation of Forsterite During Evaporation from Different Crystallographic Surfaces.

  6. Martian Meteorite Ages and Implications for Martian Cratering History

    NASA Technical Reports Server (NTRS)

    Nyquist, Laurence E.

    2006-01-01

    New radiometrically determined ages of Martian meteorites add to the growing number with crystallization ages < 1.4 Ga. The observation of mainly geologically young ages for the Martian meteorites, the only exception being the 4.5 Ga ALH84001 [1], is paradoxical when viewed in context of a Martian surface thought to be mostly much older as inferred from the surface density of meteorite craters [2]. There appears to be at least a twofold difference between the observed ages of Martian meteorites and their expected ages as inferred from the ages of Martian surfaces obtained from crater densities.

  7. THE DEAD-LIVING-MOTHER: MARIE BONAPARTE'S INTERPRETATION OF EDGAR ALLAN POE'S SHORT STORIES.

    PubMed

    Obaid, Francisco Pizarro

    2016-06-01

    Princess Marie Bonaparte is an important figure in the history of psychoanalysis, remembered for her crucial role in arranging Freud's escape to safety in London from Nazi Vienna, in 1938. This paper connects us to Bonaparte's work on Poe's short stories. Founded on concepts of Freudian theory and an exhaustive review of the biographical facts, Marie Bonaparte concluded that the works of Edgar Allan Poe drew their most powerful inspirational force from the psychological consequences of the early death of the poet's mother. In Bonaparte's approach, which was powerfully influenced by her recognition of the impact of the death of her own mother when she was born-an understanding she gained in her analysis with Freud-the thesis of the dead-living-mother achieved the status of a paradigmatic key to analyze and understand Poe's literary legacy. This paper explores the background and support of this hypothesis and reviews Bonaparte's interpretation of Poe's most notable short stories, in which extraordinary female figures feature in the narrative.

  8. Observation, Inference, and Imagination: Elements of Edgar Allan Poe's Philosophy of Science

    NASA Astrophysics Data System (ADS)

    Gelfert, Axel

    2014-03-01

    Edgar Allan Poe's standing as a literary figure, who drew on (and sometimes dabbled in) the scientific debates of his time, makes him an intriguing character for any exploration of the historical interrelationship between science, literature and philosophy. His sprawling `prose-poem' Eureka (1848), in particular, has sometimes been scrutinized for anticipations of later scientific developments. By contrast, the present paper argues that it should be understood as a contribution to the raging debates about scientific methodology at the time. This methodological interest, which is echoed in Poe's `tales of ratiocination', gives rise to a proposed new mode of—broadly abductive—inference, which Poe attributes to the hybrid figure of the `poet-mathematician'. Without creative imagination and intuition, Science would necessarily remain incomplete, even by its own standards. This concern with imaginative (abductive) inference ties in nicely with his coherentism, which grants pride of place to the twin virtues of Simplicity and Consistency, which must constrain imagination lest it degenerate into mere fancy.

  9. Application of the Allan Variance to Time Series Analysis in Astrometry and Geodesy: A Review.

    PubMed

    Malkin, Zinovy

    2016-04-01

    The Allan variance (AVAR) was introduced 50 years ago as a statistical tool for assessing the frequency standards deviations. For the past decades, AVAR has increasingly been used in geodesy and astrometry to assess the noise characteristics in geodetic and astrometric time series. A specific feature of astrometric and geodetic measurements, as compared with clock measurements, is that they are generally associated with uncertainties; thus, an appropriate weighting should be applied during data analysis. In addition, some physically connected scalar time series naturally form series of multidimensional vectors. For example, three station coordinates time series X, Y, and Z can be combined to analyze 3-D station position variations. The classical AVAR is not intended for processing unevenly weighted and/or multidimensional data. Therefore, AVAR modifications, namely weighted AVAR (WAVAR), multidimensional AVAR (MAVAR), and weighted multidimensional AVAR (WMAVAR), were introduced to overcome these deficiencies. In this paper, a brief review is given of the experience of using AVAR and its modifications in processing astrogeodetic time series.

  10. Twenty-Five Years of Applications of the Modified Allan Variance in Telecommunications.

    PubMed

    Bregni, Stefano

    2016-04-01

    The Modified Allan Variance (MAVAR) was originally defined in 1981 for measuring frequency stability in precision oscillators. Due to its outstanding accuracy in discriminating power-law noise, it attracted significant interest among telecommunications engineers since the early 1990s, when it was approved as a standard measure in international standards, redressed as Time Variance (TVAR), for specifying the time stability of network synchronization signals and of equipment clocks. A dozen years later, the usage of MAVAR was also introduced for Internet traffic analysis to estimate self-similarity and long-range dependence. Further, in this field, it demonstrated superior accuracy and sensitivity, better than most popular tools already in use. This paper surveys the last 25 years of progress in extending the field of application of the MAVAR in telecommunications. First, the rationale and principles of the MAVAR are briefly summarized. Its adaptation as TVAR for specification of timing stability is presented. The usage of MAVAR/TVAR in telecommunications standards is reviewed. Examples of measurements on real telecommunications equipment clocks are presented, providing an overview on their actual performance in terms of MAVAR. Moreover, applications of MAVAR to network traffic analysis are surveyed. The superior accuracy of MAVAR in estimating long-range dependence is emphasized by highlighting some remarkable practical examples of real network traffic analysis.

  11. Novel SLC16A2 mutations in patients with Allan-Herndon-Dudley syndrome

    PubMed Central

    Shimojima, Keiko; Maruyama, Koichi; Kikuchi, Masahiro; Imai, Ayako; Inoue, Ken; Yamamoto, Toshiyuki

    2016-01-01

    Summary Allan-Herndon-Dudley syndrome (AHDS) is an X-linked disorder caused by impaired thyroid hormone transporter. Patients with AHDS usually exhibit severe motor developmental delay, delayed myelination of the brain white matter, and elevated T3 levels in thyroid tests. Neurological examination of two patients with neurodevelopmental delay revealed generalized hypotonia, and not paresis, as the main neurological finding. Nystagmus and dyskinesia were not observed. Brain magnetic resonance imaging demonstrated delayed myelination in early childhood in both patients. Nevertheless, matured myelination was observed at 6 years of age in one patient. Although the key finding for AHDS is elevated free T3, one of the patients showed a normal T3 level in childhood, misleading the diagnosis of AHDS. Genetic analysis revealed two novel SLC16A2 mutations, p.(Gly122Val) and p.(Gly221Ser), confirming the AHDS diagnosis. These results indicate that AHDS diagnosis is sometimes challenging owing to clinical variability among patients. PMID:27672545

  12. Power spectrum and Allan variance methods for calibrating single-molecule video-tracking instruments

    PubMed Central

    Lansdorp, Bob M.; Saleh, Omar A.

    2012-01-01

    Single-molecule manipulation instruments, such as optical traps and magnetic tweezers, frequently use video tracking to measure the position of a force-generating probe. The instruments are calibrated by comparing the measured probe motion to a model of Brownian motion in a harmonic potential well; the results of calibration are estimates of the probe drag, α, and spring constant, κ. Here, we present both time- and frequency-domain methods to accurately and precisely extract α and κ from the probe trajectory. In the frequency domain, we discuss methods to estimate the power spectral density (PSD) from data (including windowing and blocking), and we derive an analytical formula for the PSD which accounts both for aliasing and the filtering intrinsic to video tracking. In the time domain, we focus on the Allan variance (AV): we present a theoretical equation for the AV relevant to typical single-molecule setups and discuss the optimal manner for computing the AV from experimental data using octave-sampled overlapping bins. We show that, when using maximum-likelihood methods to fit to the data, both the PSD and AV approaches can extract α and κ in an unbiased and low-error manner, though the AV approach is simpler and more robust. PMID:22380133

  13. THE DEAD-LIVING-MOTHER: MARIE BONAPARTE'S INTERPRETATION OF EDGAR ALLAN POE'S SHORT STORIES.

    PubMed

    Obaid, Francisco Pizarro

    2016-06-01

    Princess Marie Bonaparte is an important figure in the history of psychoanalysis, remembered for her crucial role in arranging Freud's escape to safety in London from Nazi Vienna, in 1938. This paper connects us to Bonaparte's work on Poe's short stories. Founded on concepts of Freudian theory and an exhaustive review of the biographical facts, Marie Bonaparte concluded that the works of Edgar Allan Poe drew their most powerful inspirational force from the psychological consequences of the early death of the poet's mother. In Bonaparte's approach, which was powerfully influenced by her recognition of the impact of the death of her own mother when she was born-an understanding she gained in her analysis with Freud-the thesis of the dead-living-mother achieved the status of a paradigmatic key to analyze and understand Poe's literary legacy. This paper explores the background and support of this hypothesis and reviews Bonaparte's interpretation of Poe's most notable short stories, in which extraordinary female figures feature in the narrative. PMID:27194275

  14. Petrography, Geochemistry, and Pairing Relationships of Basaltic Lunar Meteorite Miller Range 13317

    NASA Astrophysics Data System (ADS)

    Zeigler, R. A.; Korotev, R. L.

    2016-08-01

    A petrographic and geochemical description of "new" lunar meteorite MIL 13317, an evolved lunar basaltic regolith breccia. The pairing relationships with previously described lunar meteorites are also explored.

  15. Spectral Measurements of Meteorite Powders: Implications for 433 Eros

    NASA Technical Reports Server (NTRS)

    Burbine, T. H.; McCoy, T. J.; Jarosewich, E.; Sunshine, J. M.

    2001-01-01

    One of the goals of the NEAR-Shoemaker mission to 433 Eros was to determine if it has a meteoritic analog. The primary means of making such a link are the X-ray/gamma-ray spectrometers, which measure elemental compositions of the surface, and the multi-spectral imager (MSI) and near-infrared spectrometer (NIS), which measure spectral reflectance. For determining meteoritic analogs using the X-ray/gamma-ray spectrometer data, the primary data used for comparison is the set of bulk chemical analyses of meteorites done by Jarosewich. These bulk chemical analyses were done on samples now found in the Smithsonian's Analyzed Meteorite Powder collection (USNM 7073). For determining meteoritic analogs using MSI/NIS spectral data, the primary data used for comparison is the set of meteoritic spectra compiled by Gaffey. To expand the set of meteoritic spectra available to the scientific community, we have initiated a spectral study of over 70 samples (primarily ordinary chondrites) found in the Smithsonian's Analyzed Meteorite Powder collection and an electron microprobe study of their corresponding thin sections. This set of spectral and compositional data should allow for better constraints on the distribution of meteorites in plots of band area ratios versus Band I centers and the usefulness of equations for deriving mineralogic compositions from band parameters. These spectral data can also be combined with previous spectral studies of other meteorite types such as the primitive achondrites, eucrites, and angrites to determine how useful the derived band parameters are for differentiating between different meteorite classes. These spectral data can also be used for testing the Modified Gaussian Model (MGM) for determining modal abundances and mafic mineral chemistries from reflectance spectra.

  16. Mechanical properties of several Fe-Ni meteorites

    SciTech Connect

    Mulford, Roberta N; El - Dasher, Bassem

    2010-10-28

    The strength and elastic constants of meteorites are of increasing interest as predictions of meteorite impacts on earth come within the realm of possibility. In addition, meteorite impacts on extraterrestrial bodies provide an excellent sampling tool for evaluation of planetary compositions and properties. Fe-Ni meteorites provide a well-defined group of materials of fairly uniform composition. Iron-nickel meteorites exhibit a unique lamellar microstructure, a Widmanstatten structure, consisting of small regions with steep-iron-nickel composition gradients. This microstructure is found in the Fe-Ni system only in meteorites, and is believed to arise as a result of slow cooling in a planetary core or other large mass. Meteorites with compositions consisting of between 5 and 17% nickel in iron are termed 'octahedrite,' and further characterized according to the width of the Ni-poor kamacite bands; 'fine,' (0.2-0.5 mm) 'medium,' (0.5-1.3 mm) and 'coarse,' (1.5-3.3 mm). Many meteorites have inclusions and structures indicating that the material has been shocked at some point early in its evolution. Several Iron-nickel meteorites have been examined using Vickers and spherical indentation, x-ray fluorescence, and EBSD. Direct observation of mechanical properties in these highly structured materials provides a valuable supplement to bulk measurements, which frequently exhibit large variation in dynamic properties, even within a single sample. Previous studies of the mechanical properties of a typical iron-nickel meteorite, a Diablo Canyon specimen, indicated that the strength of the composite was higher by almost an order of magnitude than values obtained from laboratory-prepared specimens. Additional meteorite specimens have been examined to establish a range of error on the previously measured yield, to determine the extent to which deformation upon re-entry contributes to yield, and to establish the degree to which the strength varies as a function of microstructure.

  17. Martian meteorite Dhofar 019: A new shergottite

    NASA Astrophysics Data System (ADS)

    Taylor, L. A.; Nazarov, M. A.; Shearer, C. K.; McSween, H. Y., Jr.; Cahill, J.; Neal, C. R.; Ivanova, M. A.; Barsukova, L. D.; Lentz, R. C.; Clayton, R. N.; Mayeda, T. K.

    2002-08-01

    Dhofar 019 is a new martian meteorite found in the desert of Oman. In texture, mineralogy, and major and trace element chemistry, this meteorite is classified as a basaltic shergottite. Olivine megacrysts are set within a groundmass composed of finer grained olivine, pyroxene (pigeonite and augite), and maskelynite. Minor phases are chromite-ulvöspinel, ilmenite, silica, K-rich feldspar, merrillite, chlorapatite, and pyrrhotite. Secondary phases of terrestrial origin include calcite, gypsum, celestite, Fe hydroxides, and smectite. Dhofar 019 is most similar to the Elephant Moraine (EETA) 79001 lithology A and Dar al Gani (DaG) 476/489 shergottites. The main features that distinguish Dhofar 019 from other shergottites are lack of orthopyroxene; lower Ni contents of olivine; the heaviest oxygen-isotopic bulk composition; and larger compositional ranges for olivine, maskelynite, and spinel, as well as a wide range for pyroxenes. The large compositional ranges of the minerals are indicative of relatively rapid crystallization. Modeling of olivine chemical zonations yield minimum cooling rates of 0.5-0.8 ?C/h. Spinel chemistry suggests that crystallization took place under one of the most reduced conditions for martian meteorites, at an oxygen fugacity of 3 log units below the quartz-fayalite-magnetite (QFM) buffer. The olivine megacrysts are heterogeneously distributed in the rock. Crystal size distribution analysis suggests that they constitute a population formed under steady-state conditions of nucleation and growth, although a few grains may be cumulates. The parent melt is thought to have been derived from partial melting of a light rare earth element- and platinum group element-depleted mantle source. Shergottites, EETA79001 lithology A, DaG 476/489, and Dhofar 019, although of different ages, comprise a particular type of martian rocks. Such rocks could have formed from chemically similar source(s) and parent melt(s), with their bulk compositions affected by

  18. Metamorphism of eucrite meteorites studied quantitatively using induced thermoluminescence

    NASA Technical Reports Server (NTRS)

    Batchelor, J. David; Sears, Derek W. G.

    1991-01-01

    Induced thermoluminescence studies provide a new and quantitative means of determining relative metamorphic intensities for eucrite meteorites, the simplest and most ancient products of basaltic volcanism. Using this technique, it is shown that the eucrites constitute a continuous metamorphic series and not, as commonly assumed, two groups of metamorphosed and nonmetamorphosed meteorites. It is suggested that the method may have applications to other basalts.

  19. Discovery of Biological Structures in the Tissint Mars Meteorite

    NASA Astrophysics Data System (ADS)

    Wallis, J.; Wickramasinghe, N. C.; Wallis, Daryl; Miyake, Nori; Wallis, Max; Di Gregorio, Barry; Mufti, Shirwan Al

    2012-03-01

    Preliminary SEM/EDAX studies of the Tissint meteorite shows projections of interior spherical globules rich in C and O. Such concentrations of carbonaceous material in a matrix of mineral grains poses a mystery if biological processes are excluded. They are consistent with remnants of biological structures, thus supporting earlier similar claims for the Mars meteorite ALH84001..

  20. Atom-Probe Measurements of Meteoritic Nanodiamonds and Terrestrial Standards

    NASA Astrophysics Data System (ADS)

    Lewis, J. B.; Isheim, D.; Floss, C.; Daulton, T. L.; Seidman, D. N.; Heck, P. R.; Davis, A. M.; Pellin, M. J.; Savina, M. R.; Hiller, J.; Mane, A.; Elam, J. W.; Stephan, T.

    2013-09-01

    We present new data from the novel application of atom-probe tomography to the study of nanodiamonds from the meteorite Allende. The mean meteoritic ^12C/^13C peak ratio is higher than that of our standards, but there are instrumental artifacts.

  1. Meteorites - The Significance of Collection and Curation and Future Developments

    NASA Astrophysics Data System (ADS)

    Smith, Caroline

    2015-03-01

    Meteorites are some of the most important and valuable rocks available for scientific study. Approximately 43,000 meteorites are known on Earth and are egeologicalf samples of extraterrestrial bodies - meteorites are known to originate from asteroids, the Moon, Mars and possibly comets. With expanding exploration of our Solar System, meteorites provide the eground truthf to compare data collected by robotic missions with results gained from a variety of more accurate and precise techniques using laboratories on Earth. This talk will give an introduction to the history of meteorite science and the importance of meteorite collections to the field of meteoritics, planetary and solar system science. Curation of extraterrestrial samples is a particularly pertinent issue, especially with regards to particularly rare samples such as those from Mars like the recent Tissint meteorite. Future sample return missions to asteroids and Mars also pose siginificant challenges around the curation of these precious materials. Issues surrounding the curation of samples and how curation and curatorial actions can influence scientific studies will also be discussed.

  2. A New Old Meteorite Find from Claromeco, Argentina

    NASA Astrophysics Data System (ADS)

    Acevedo, R. D.; Subías, I.

    2012-09-01

    Two reddish brown meteoritic stones of 13 kg each were found in 1963 leaning against a windmill in a farm at argentine pampas (38º 48" 16"" S, 60º 07" 23"" W), but they are the focus of attention just now. This meteorite could be classified as a LL ordinary chondrite.

  3. Carbonaceous meteorites contain a wide range of extraterrestrial nucleobases.

    PubMed

    Callahan, Michael P; Smith, Karen E; Cleaves, H James; Ruzicka, Josef; Stern, Jennifer C; Glavin, Daniel P; House, Christopher H; Dworkin, Jason P

    2011-08-23

    All terrestrial organisms depend on nucleic acids (RNA and DNA), which use pyrimidine and purine nucleobases to encode genetic information. Carbon-rich meteorites may have been important sources of organic compounds required for the emergence of life on the early Earth; however, the origin and formation of nucleobases in meteorites has been debated for over 50 y. So far, the few nucleobases reported in meteorites are biologically common and lacked the structural diversity typical of other indigenous meteoritic organics. Here, we investigated the abundance and distribution of nucleobases and nucleobase analogs in formic acid extracts of 12 different meteorites by liquid chromatography-mass spectrometry. The Murchison and Lonewolf Nunataks 94102 meteorites contained a diverse suite of nucleobases, which included three unusual and terrestrially rare nucleobase analogs: purine, 2,6-diaminopurine, and 6,8-diaminopurine. In a parallel experiment, we found an identical suite of nucleobases and nucleobase analogs generated in reactions of ammonium cyanide. Additionally, these nucleobase analogs were not detected above our parts-per-billion detection limits in any of the procedural blanks, control samples, a terrestrial soil sample, and an Antarctic ice sample. Our results demonstrate that the purines detected in meteorites are consistent with products of ammonium cyanide chemistry, which provides a plausible mechanism for their synthesis in the asteroid parent bodies, and strongly supports an extraterrestrial origin. The discovery of new nucleobase analogs in meteorites also expands the prebiotic molecular inventory available for constructing the first genetic molecules.

  4. On the Cometary Origin of the Polonnaruwa Meteorite

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, N. C.; Wallis, J.; Wallis, D. H.; Wallis, M. K.; Al-Mufti, S.; Wickramasinghe, J. T.; Samaranayake, Anil; Wickramarathne, K.

    2013-01-01

    The diatoms discovered in the Polonnaruwa meteorite are interpreted as originating in comets and the dust in interstellar space. The exceptionally porous structure of the Polonnaruwa meteorite points to it being a recently denuded cometary fragment. Microorganisms that were present in a freeze-dried state within pores and cavities may have survived entry to be added to the terrestrial biosphere.

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

    PubMed Central

    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 (exemplified 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 l-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. PMID:27413780

  6. Gold in meteorites and in the earth's crust

    USGS Publications Warehouse

    Jones, Robert Sprague

    1968-01-01

    The reported gold contents of meteorites range from 0.0003 to 8.74 parts per million. Gold is siderophilic, and the greatest amounts in meteorites are in the iron phases. Estimates ,of the gold content of the earth's crust are in the range of 0.001 to 0.006 parts per million.

  7. Fullerenes and Noble Gases in the Murchison and Allende Meteorites

    NASA Technical Reports Server (NTRS)

    Becker, Luann; Poreda, Robert J.; Bunch, Ted E.

    2000-01-01

    In this work we report the detection of fullerenes (C60 to C250) in the Murchison and Allende meteorites. By exploiting the unique ability of these molecules to trap noble gases, we have determined that fullerene is indeed a new carrier phase for noble gases in meteorites.

  8. Radioactivities in returned lunar materials and in meteorites

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.

    1982-01-01

    Carbon-14 measurements were made for meteorites with a Van der Graaf accelerator. Accelerator C-14 dating improved the precision by a factor of ten, allowed the use of smaller sample sizes, and gave speedier results than C-14 dating with counters. A methodology for determining the terrestrial ages of several antarctic meteorites is described and the results are listed.

  9. Antarctic meteorite descriptions 1976-1977-1978-1979

    NASA Technical Reports Server (NTRS)

    Score, R.; Schwarz, C. M.; King, T. V. V.; Mason, B.; Bogard, D. D.; Gabel, E. M.

    1981-01-01

    All previously distributed meteorite data sheets, plus a number of new ones for 1979 chondrites are included. A comprehensive sample index listing meteorite name/number, classification, and weathering category is also included. Separate indexes listing all petrologic type 3 and type 4 chondrites, all irons, all achondrites, and all carbonaceous chondrites in the collection is provided.

  10. Dynamical evidence regarding the relationship between asteroids and meteorites

    NASA Technical Reports Server (NTRS)

    Wetherill, G. W.

    1978-01-01

    Meteorites are fragments of small solar system bodies transferring into the vicinity of earth from the inner edge of the asteroid belt. Photometric measurements support an association between Apollo objects and chondritic meteorites. Dynamical arguments indicate that most Apollo objects are devolatilized comet residues, however; petrographic and cosmogonical reasons argue against this conclusion.

  11. Carbonaceous Meteorites Contain a Wide Range of Extraterrestrial Nucleobases

    NASA Technical Reports Server (NTRS)

    Callahan, Michael P.; Smith, Karen E.; Cleaves, H. James, II; Ruzicka, Josef; Stern, Jennifer C.; Glavin, Daniel P.; House, Christopher H.; Dworkin, Jason P.

    2011-01-01

    All terrestrial organisms depend on nucleic acids (RNA and DNA), which use pyrimidine and purine nucleobases to encode genetic information. Carbon-rich meteorites may have been important sources of organic compounds required for the emergence of life on the early Earth; however, the origin and formation of nuc1eobases in meteorites has been debated for over 50 y. So far, the few nuc1eobases reported in meteorites are biologically common and lacked the structural diversity typical of other indigenous meteoritic organics. Here, we investigated the abundance and distribution of nucleobases and nucleobase analogs in formic acid extracts of 12 different meteorites by liquid chromatography-mass spectrometry. The Murchison and Lonewolf Nunataks 94102 meteorites contained a diverse suite of nucleobases, which included three unusual and terrestrially rare nucleobase analogs; purine, 2,6-diminopurine, and 6,8-diaminopurine. In a parallel experiment, we found an identical suite of nucleobases and nucleobase analogs generated in reactions of ammonium cyanide. Additionally, these nucleobase analoge were not detected above our parts-per-billion detection limits in any of the procedural blanks, control samples, a terrestrial soil sample, and an Antarctic ice sample. Our results demonstrate that the purines detected in meteorites are consistent with products of ammonium cyanide chemistry, which provides a plausible mechanism for their synthesis in the asteroid parent bodies, and strongly supports an extraterrestrial origin. The discovery of new nucleobase analogs in meteorites also expands the prebiotic molecular inventory available for constructing the first genetic molecules.

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

    PubMed

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

    2016-06-22

    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 (exemplified 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 l-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. PMID:27413780

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

    PubMed

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

    2016-06-22

    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 (exemplified 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 l-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.

  14. Spectral Measurements of Meteorite Powders: Implications for 433 Eros

    NASA Technical Reports Server (NTRS)

    Burbine, T. H.; McCoy, T. J.; Jarosewich, E.; Sunshine, J. M.

    2002-01-01

    We are re-examining the regions defined by different meteorite classes in Band Area Ratio plots by measuring more meteorite samples. These data will allow us to better determine asteroid compositions from spectral measurements. Additional information is contained in the original extended abstract.

  15. Martian surface paleotemperatures from thermochronology of meteorites.

    PubMed

    Shuster, David L; Weiss, Benjamin P

    2005-07-22

    The temporal evolution of past martian surface temperatures is poorly known. We used thermochronology and published noble gas and petrographic data to constrain the temperature histories of the nakhlites and martian meteorite ALH84001. We found that the nakhlites have not been heated to more than 350 degrees C since they formed. Our calculations also suggest that for most of the past 4 billion years, ambient near-surface temperatures on Mars are unlikely to have been much higher than the present cold (<0 degrees C) state. PMID:16040703

  16. Martian Surface Paleotemperatures from Thermochronology of Meteorites

    NASA Astrophysics Data System (ADS)

    Shuster, David L.; Weiss, Benjamin P.

    2005-07-01

    The temporal evolution of past martian surface temperatures is poorly known. We used thermochronology and published noble gas and petrographic data to constrain the temperature histories of the nakhlites and martian meteorite ALH84001. We found that the nakhlites have not been heated to more than 350°C since they formed. Our calculations also suggest that for most of the past 4 billion years, ambient near-surface temperatures on Mars are unlikely to have been much higher than the present cold (<0°C) state.

  17. Zinc isotope anomalies in Allende meteorite inclusions

    NASA Technical Reports Server (NTRS)

    Loss, R. D.; Lugmair, G. W.

    1990-01-01

    The isotopic compositions of Zn, Cr, Ti, and Ca have been measured in a number of CAIs from the Allende meteorite. The aim was to test astrophysical models which predict large excesses of Zn-66 to accompany excesses in the neutron-rich isotopes of Ca, Ti, Cr, and Ni. Some of the CAIs show clearly resolved but small excesses for Zn-66 which are at least an order of magnitude smaller than predicted. This result may simply reflect the volatility and chemical behavior of Zn as compared to the other (more refractory) anomalous elements found in these samples. Alternatively, revision of parameters and assumptions used for the model calculations may be required.

  18. Nonprotein Amino Acids in the Murchison Meteorite

    PubMed Central

    Kvenvolden, Keith A.; Lawless, James G.; Ponnamperuma, Cyril

    1971-01-01

    Twelve nonprotein amino acids appear to be present in the Murchison meteorite. The identity of eight of them has been conclusively established as N-methylglycine, β-alanine, 2-methylalanine, α-amino-n-butyric acid, β-amino-n-butyric acid, γ-amino-n-butyric acid, isovaline, and pipecolic acid. Tentative evidence is presented for the presence of N-methylalanine, N-ethylglycine, β-aminoisobutyric acid, and norvaline. These amino acids appear to be extraterrestrial in origin and may provide new evidence for the hypothesis of chemical evolution. PMID:16591908

  19. Organic material: Asteroids, meteorites, and planetary satellites

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; Kerridge, John F.

    1992-01-01

    Telescopic observations in in situ spacecraft investigations over the last two decades have shown that many planetary satellites, asteroids, and comets have surfaces containing very dark material that is either neutral (black) or red in color. Although comets are not the focus of this paper, the possible relationship of comets to asteroids, meteorites, and interplanetary dust is briefly discussed in the context of their dark-matter component. The following topics are discussed with respect to their organic content: carbonaceous chondrites; asteroids; low-albedo planetary satellites; and Pluto, Charon, and Triton. Laboratory studies and a summary are also presented.

  20. Matching, maximizing, and hill-climbing

    PubMed Central

    Hinson, John M.; Staddon, J. E. R.

    1983-01-01

    In simple situations, animals consistently choose the better of two alternatives. On concurrent variable-interval variable-interval and variable-interval variable-ratio schedules, they approximately match aggregate choice and reinforcement ratios. The matching law attempts to explain the latter result but does not address the former. Hill-climbing rules such as momentary maximizing can account for both. We show that momentary maximizing constrains molar choice to approximate matching; that molar choice covaries with pigeons' momentary-maximizing estimate; and that the “generalized matching law” follows from almost any hill-climbing rule. PMID:16812350