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1. A diversity of temperature and pressure conditions recorded by zircon within suevite from Ries crater, Germany.

Author

Stadermann, A. C., Erickson, T. M., Seifert, L. B., Chang, Y., Zeszut, Z., Zega, T. J., Michels, Z. D., and Barnes, J. J.

Subjects
ZIRCON, CRATERING, MINERALS, TEMPERATURE, REFRACTORY materials, IMPACT craters
Abstract

The temperature and pressure conditions experienced by rocks during an impact event can be constrained using petrologic and microstructural analysis and is crucial to providing ground truth to the impact cratering process. Suevite is a polymict, impact melt‐bearing breccia, specific to Ries crater in Germany. There are competing models for suevite formation and emplacement, such as clastic flows pushed out of the crater rim or ejecta plume fallback. Knowledge of the temperature and pressure pathways recorded by grains within the suevite can help distinguish between these and other models. The accessory phase zircon (ZrSiO4) and its high‐pressure polymorph reidite are particularly useful in such circumstances as they are highly refractory minerals that can record the high‐temperature and/or high‐pressure conditions of an impact event. Here, we present evidence for a wide array of temperature and pressure conditions recorded in zircon grains within a single thin section of suevite. Zircons in this study range from unshocked to highly shocked (>53 GPa), and record temperatures more than 1673°C. These findings confirm previous studies concluding that suevites contain material exposed to very diverse pressure and temperature conditions during initial shock compression and excavation but do not, as a whole, experience extreme temperatures (>1673°C) or pressures (>30 GPa). [ABSTRACT FROM AUTHOR]

Published
2024
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2. Isotopic and Microstructural Analyses of Opaque Mineral Assemblages and Their Alteration Products Hosted in a Refractory Inclusion

Author

Mane, P, Zega, T. J, Nguyen, A. N, and Simon, J. I

Subjects
Space Sciences (General)
Abstract

Calcium-aluminum-rich inclusions (CAIs) hosted in primitive meteorites are the oldest solids formed in the Solar System. Some CAIs contain metal nuggets that are complex assemblages of Fe-Ni alloys, along with rare ultra-refractory metals such as platinum group elements (PGEs), and their alteration products such as magnetite, sulfides, and phosphates. Three possible mechanisms proposed to explain the origin of these metal nuggets include condensation in circumstellar settings, condensation in the solar nebula within the CAI-forming region, or crystallization from immiscible metal-silicate melt. However, secondary alteration processes may have also affected some of these assemblages. Additionally, similar metal assemblages observed in chondrules and chondritic matrix indicate that all of these metal nuggets could share common high-temperature origins. These metal assemblages record early Solar System conditions that are reflected in their distinctive chemical composition, mineralogy and microstructures. Here we report a detailed mineralogical, microstructural and oxygen isotopic study of one such metal assemblage hosted in a CAI to understand the physical and chemical settings in which it formed.

Published
2020

4. Volatiles, vesicles, and vugs: Unraveling the magmatic and eruptive histories of Steno crater basalts.

Author

Wilbur, Z. E., Barnes, J. J., Eckley, S. A., Ong, I. J., Brounce, M., Crow, C. A., Erickson, T., Kent, J. J., Boyce, J. W., Mosenfelder, J. L., Hahn, T., McCubbin, F. M., and Zega, T. J.

Subjects
BASALT, LUNAR craters, LAVA flows, PETROLOGY, MINERALOGY, APATITE
Abstract

In 1972, Apollo 17 astronauts returned 170.4 kg of lunar material. Within 1 month of their return, a subset of those samples was specially curated with the forethought that future analytical techniques would offer new insight into the formation and evolution of the Moon. Of interest in this work is sample 71036, a basalt collected from the rim of Steno crater in the Taurus–Littrow Valley, which was stored frozen and was processed and released for study 50 years later. We report, for the first time, the detailed mineralogy and petrology of 71036 and its companion samples 71035, 71037, and 71055 using a novel combination of 2‐D and 3‐D methods. We investigate lunar volatiles through in situ measurements of apatite and 3‐D measurements of vesicles to understand the degassing histories of the Steno crater basalts. Our coupled 2‐D petrography and 3‐D tomography data sets support a model of the Steno crater basalts crystallizing in the upper crust of a mare lava flow. Apatite F and OH chemistry and the late‐stage deformation of voids and formation of smaller vesicles provide evidence supporting coeval degassing of volatiles and crystallization of mesostasis apatite in Apollo 17 basalts. This work helps to close knowledge gaps surrounding the origin, magmatic evolution, emplacement, and crystallization history of high‐titanium basalts. [ABSTRACT FROM AUTHOR]

Published
2023
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5. Properties of Rubble-Pile Asteroid (101955) Bennu from OSIRIS-REx Imaging and Thermal Analysis

Author

DellaGiustina, D. N, Emery, J. P, Golish, D. R, Rozitis, B, Bennett, C. A, Burke, K. N, Ballouz, R.-L, Becker, K. J, Christensen, P. R, Drouet d’Aubigny, C. Y, Hamilton, V. E, Reuter, D. C, Rizk, B, Simon, A. A, Asphaug, E, Bandfield, J. L, Barnouin, O. S, Barucci, M. A, Binzel, R. P, Bottke, W. F, Bowles, N. E, Campins, H, Clark, B. C, Clark, B. E, Connolly, H. C., Jr, Daly, M. G, de Leon, J, Delbo, M, Deshapriya, J. D. P, Fornasier, S, Hergenrother, C. W, Jawin, E. R, Howell, E. S, Kaplan, H. H, Kareta, T. R, Corre, L. Le, Li, J.-Y, Licandro, J, Lim, L. F, Michel, P, Molaro, J, Nolan, M. C, Popescu, M, Rizos Garcia, J. L, Ryan, A, Schwartz, S. R, Shultz, N, Siegler, M. A, Smith, P. H, Tatsumi, E, Thomas, C. A, Walsh, K. J, Wolner, C. W. V, Zou, X.-D, Lauretta, D. S, Highsmith, D. E, Small, J, Vokrouhlick, D, Brown, E, Hanna, K. L. Donaldson, Warren, T, Brunet, C, Chicoine, R. A, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, D. L, Bayron, J, Golubov, O, Sánchez, P, Stromberg, J, Hirabayashi, M, Hartzell, C. M, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, McGraw, L, Ghent, R, Al Asad, M. M, Johnson, C. L, Philpott, L, Susorney, H. C. M, Cloutis, E. A, Hanna, R. D, Ciceri, F, Hildebrand, A. R, Ibrahim, E.-M, Breitenfeld, L, Glotch, T, Rogers, A. D, Ferrone, S, Fernandez, Y, Chang, W, Cheuvront, A, Trang, D, Tachibana, S, Yurimoto, H, Brucato, J. R, Poggiali, G, Pajola, M, Dotto, E, Mazzotta Epifani, E, Crombie, M. K, Lantz, C, Izawa, M. R. M, Leon, J. de, Clemett, S, Thomas-Keprta, K, Van wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Chesley, S. R, Elder, C. M, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, J. M, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, B, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Bierhaus, E. B, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, M. E, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhl, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Audi, E, Bandrowski, R, Becker, T. L, Bendall, S, Bloomenthal, H, Blum, D, Boynton, W. V, Brodbeck, J, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, Dean, D, Diallo, B, Drinnon, D, Drozd, K, Enos, H. L, Enos, R, Fellows, C, Ferro, T, Fisher, M. R, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Huettner, E, Janakus, A, Jones, J, Kidd, J, Kingsbury, K, Balram-Knutson, S. S, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Maleszewski, C. K, Malhotra, R, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Roper, H. L, Salazar, S, Selznick, S, Stewart, S, Sutton, S, Swindle, T, Tang, Y. H, Westermann, M, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Pino Munoz, D, Watanabe, S.-I, Sandford, S. A, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Dworkin, J. P, Cook, J. Elsila, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, E. M, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, L. P, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, R. W, Le Corre, L, Molaro, J. L, Palmer, E. E, Tricarico, P, Weirich, J. R, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Haberle, C. W, Mehall, G, Rios, K, Franchi, I, Beddingfield, C. B, Marshall, J, Brack, D. N, French, A. S, McMahon, J. W, Scheeres, D. J, McCoy, T. J, Russell, S, Killgore, M, Chodas, M, Lambert, M, Masterson, R. A, Freemantle, J, Seabrook, J. A, Craft, K, Daly, R. T, Ernst, C, Espiritu, R. C, Holdridge, M, Jones, M, Nair, A. H, Nguyen, L, Peachey, J, Perry, M. E, Plescia, J, Roberts, J. H, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Libourel, G, Thuillet, F, and Marty, B

Subjects
Lunar And Planetary Science And Exploration
Abstract

Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces. Using images and thermal data from NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft, we show that asteroid (101955) Bennu's surface is globally rough, dense with boulders, and low in albedo. The number of boulders is surprising given Bennu's moderate thermal inertia, suggesting that simple models linking thermal inertia to particle size do not adequately capture the complexity relating these properties. At the same time, we find evidence for a wide range of particle sizes with distinct albedo characteristics. Our findings imply that ages of Bennu's surface particles span from the disruption of the asteroid's parent body (boulders) to recent in situ production (micrometre-scale particles).

Published
2019
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6. Simulating Space Weathering in the Transmission Electron Microscope via Dynamic in Situ Heating and Helium Irradiation of Olivine

Author

Thompson, M. S, Haenecour, P, Howe, J. Y, Laczniak, D. L, Zega, T. J, Hu, J, Chen, W, Keller, L. P, and Christoffersen, R

Subjects
Space Sciences (General)
Abstract

The chemical composition, microstructure, and optical properties of grains on the surfaces of airless bodies are predominantly altered by micrometeorite impacts and solar wind irradiation. These processes drive space weathering and result in the formation of features including chemically-altered, amorphous grain rims, Fe nanoparticles (npFe), and vesiculated grain textures. These characteristics have been identified in returned samples from the surfaces of the Moon and asteroid Itokawa. In order to advance our understanding of the formation of these microstructural and chemical features in returned samples, we have simulated space weathering processes for a variety of materials via laboratory experiments. These experiments include ion irradiation to simulate solar wind exposure and laser irradiation and in situ heating to simulate micrometeorite impacts. While these experiments have provided considerable insight into the formation mechanisms of many space weathering features, they are predominantly static and typically performed separately. Here we present results from the simulated space weathering of olivine grains via He irradiation and dynamic heating, both performed in situ inside the transmission electron microscope (TEM). These experiments allow for the real-time observation of chemical and microstructural changes resulting from the superposed effects of ion irradiation and pulsed heating.

Published
2019

7. The CAESAR New Frontiers Mission: 1. Expected Nature of the Returned Comet Sample

Author

Lauretta, D. S, Squyres, S. W, Bermudez, L, Blake, G, Canham, J. S, Chu, P. C, Clemett, S, Dworkin, J. P, Furukawa, Y, Gerakines, P. A, Glavin, D. P, Herd, C. D. K, Houghton, M. B, Kimura, Y, Lorentson, C. C, Makowski, J. M, Messenger, S, Milam, S, Mumma, M, Nakamura-Messenger, K, Nakamura, T, Nguyen, A, Oberg, D, Pace, L. F, Spring, J. W, Takigawa, A, Violet, M, Zacny, K, and Zega, T. J

Subjects
Lunar And Planetary Science And Exploration
Abstract

Comets are time capsules from the birth of our Solar System that record pre-solar history, the initial stages of planet formation, and the sources of prebiotic organics and volatiles for the origin of life. These capsules can only be opened in laboratories on Earth. CAESAR (Comet Astrobiology Exploration Sample Return)’s sample analysis objectives are to understand the nature of Solar System starting materials and how these components came together to form planets and give rise to life. Examination of these comet nucleus surface samples in laboratories around the world will also provide ground truth to remote observations of the innumerable icy bodies of the Solar System.

Published
2019

8. Coordinated Microanalysis of Phosphates in High-Titanium Lunar Basalts

Author

Barnes, J. J, Thompson, M. S, Mccubbin, F. M, Howe, J. Y, Rahman, Z, Messenger, S, and Zega, T

Subjects
Space Sciences (General)
Abstract

Laboratory studies of lunar apatite [Ca5(PO4)3(F,Cl,OH)] have been important for determining the volatile inventory of the interior and the roles volatiles played during the magmatic evolution of the Moon. It has been suggested that high-Ti mare basalts sample volatiles from a distinct reservoir in the lunar mantle. However, there is still debate surrounding the crystallization and post-crystallization history of apatite in those basalts. This information is required before we can use apatite to characterize the abundance or isotopic composition of volatiles in melts or magmatic source regions. Our goal is to investigate the mineral chemistry, crystal structure, and volatile inventory of phosphates in high-Ti basalts from Apollo 11, which will allow us to determine the crystallization history of apatite in these rocks and identify any potential secondary processes that have changed the volatile composition that apatite acquired from the melt.

Published
2018

9. The Caesar New Frontiers Mission: 2. Sample Science

Author

Lauretta, D. S, Squyres, S. W, Messenger, S, Nakamura-Messenger, D, Nakamura, T, Glavin, D. P, Dworkin, J. P, Nguyen, A, Clemett, S, Furukawa, Y, Kimura, Y, Takigawa, A, Blake, G, Zega, T. J, Mumma, M, Milam, S, and Herd, C. D. K

Subjects
Lunar And Planetary Science And Exploration
Published
2018

10. Craters, boulders and regolith of (101955) Bennu indicative of an old and dynamic surface

Author

Walsh, KJ, Jawin, ER, Ballouz, R-L, Barnouin, OS, Bierhaus, EB, Jr, CHC, Molaro, JL, McCoy, TJ, Delbo', M, Hartzell, CM, Pajola, M, Schwartz, SR, Trang, D, Asphaug, E, Becker, KJ, Beddingfield, CB, Bennett, CA, Bottke, WF, Burke, KN, Clark, BC, Daly, MG, Dellagiustina, DN, Dworkin, JP, Elder, CM, Golish, DR, Hildebrand, AR, Malhotra, R, Marshall, J, Michel, P, Nolan, MC, Perry, ME, Rizk, B, Ryan, A, Sandford, SA, Scheeres, DJ, Susorney, HCM, Thuillet, F, Lauretta, DS, Highsmith, DE, Small, J, Vokrouhlicky, D, Bowles, NE, Brown, E, Hanna, KLD, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, DL, Bayron, J, Golubov, O, Sanchez, P, Stromberg, J, Hirabayashi, M, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, Emery, JP, McGraw, L, Ghent, R, Binzel, RP, Asad, MM, Johnson, CL, Philpott, L, Cloutis, EA, Hanna, RD, Ciceri, F, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Clark, BE, Ferrone, S, Thomas, CA, Campins, H, Fernandez, Y, Chang, W, Cheuvront, A, Tachibana, S, Yurimoto, H, Brucato, JR, Poggiali, G, Dotto, E, Epifani, EM, Crombie, MK, Lantz, C, Izawa, MRM, De Leon, J, Licandro, J, Garcia, JLR, Clemett, S, Thomas-Keprta, K, Van Wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Chesley, SR, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, JM, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Barucci, MA, Deshapriya, JDP, Fornasier, S, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Audi, E, Bandrowski, R, Becker, TL, Bendall, S, Bloomenthal, H, Blum, D, Boynton, WV, Brodbeck, J, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, D'Aubigny, CYD, Dean, D, Diallo, B, Drinnon, D, Drozd, K, Enos, HL, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Hergenrother, CW, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Howell, ES, Huettner, E, Janakus, A, Jones, J, Kareta, TR, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Maleszewski, CK, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Roper, HL, Salazar, S, Selznick, S, Shultz, N, Smith, PH, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CWV, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S-I, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Lim, LF, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, EM, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Reuter, DC, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Simon, AA, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, LP, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, RW, Le Corre, L, Li, J-Y, Palmer, EE, Siegler, MA, Tricarico, P, Weirich, JR, Zou, X-D, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Christensen, PR, Haberle, CW, Mehall, G, Rios, K, Franchi, I, Rozitis, B, Brack, DN, French, AS, McMahon, JW, Russell, S, Killgore, M, Hamilton, VE, Kaplan, HH, Bandfield, JL, Chodas, M, Lambert, M, Masterson, RA, Freemantle, J, Seabrook, JA, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo, M, Libourel, G, Marty, B, Team, O-R, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), ASU School of Earth and Space Exploration (SESE), Arizona State University [Tempe] (ASU), IHU-LIRYC, Université Bordeaux Segalen - Bordeaux 2-CHU Bordeaux [Bordeaux], NASA Goddard Space Flight Center (GSFC), National Dairy Research Institute, SETI Institute, Institute of Northern Engineering, 455 Duckering Bldg, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Centre de Mise en Forme des Matériaux (CEMEF), Centre National de la Recherche Scientifique (CNRS)-PSL Research University (PSL)-MINES ParisTech - École nationale supérieure des mines de Paris, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and ANR-15-IDEX-0001,UCA JEDI,Idex UCA JEDI(2015)

Subjects
Near-Earth object, 010504 meteorology & atmospheric sciences, Mass movement, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Geomorphology, 010502 geochemistry & geophysics, 01 natural sciences, Billion years, Regolith, Astrobiology, [SPI]Engineering Sciences [physics], Asteroids comets and Kuiper belt, Impact crater, Asteroid, General Earth and Planetary Sciences, Asteroid belt, Early solar system, Geology, 0105 earth and related environmental sciences
Abstract

著者人数: 38名ほか (The OSIRIS-REx Team: 所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): Van wal, S; 吉川, 真; 渡邊, 誠一郎), Number of authors: 38 and The OSIRIS-REx Team (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Van wal, S; Yoshikawa, Makoto; Watanabe, Sei-icihro), Accepted: 2019-02-11, 資料番号: SA1190038000

Published
2019
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11. Nanoscale Analysis of Space-Weathering Features in Soils from Itokawa

Author

Thompson, M. S, Christoffersen, R, Zega, T. J, and Keller, L. P

Subjects
Lunar And Planetary Science And Exploration
Abstract

Space weathering alters the spectral properties of airless body surface materials by redden-ing and darkening their spectra and attenuating characteristic absorption bands, making it challenging to characterize them remotely [1,2]. It also causes a discrepency between laboratory analysis of meteorites and remotely sensed spectra from asteroids, making it difficult to associate meteorites with their parent bodies. The mechanisms driving space weathering include mi-crometeorite impacts and the interaction of surface materials with solar energetic ions, particularly the solar wind. These processes continuously alter the microchemical and structural characteristics of exposed grains on airless bodies. The change of these properties is caused predominantly by the vapor deposition of reduced Fe and FeS nanoparticles (npFe(sup 0) and npFeS respectively) onto the rims of surface grains [3]. Sample-based analysis of space weathering has tra-ditionally been limited to lunar soils and select asteroidal and lunar regolith breccias [3-5]. With the return of samples from the Hayabusa mission to asteroid Itoka-wa [6], for the first time we are able to compare space-weathering features on returned surface soils from a known asteroidal body. Analysis of these samples will contribute to a more comprehensive model for how space weathering varies across the inner solar system. Here we report detailed microchemical and microstructal analysis of surface grains from Itokawa.

Published
2014

12. Microchemical and Structural Evidence for Space Weathering in Soils from Asteroid Itokawa

Author

Thompson, M. S, Christoffersen, R, and Zega, T. J

Subjects
Chemistry And Materials (General), Geophysics, Lunar And Planetary Science And Exploration
Abstract

The chemistry, microstructure and optical properties of grains on the surfaces of airless bodies are continu-ously modified due to their interactions predominantly with solar energetic ions and micrometeorite impacts. Collectively known as space weathering, this phenomenon results in a discrepancy between remotely sensed spectra from asteroids and those ac-quired directly from meteorites. The return of pristine samples from the asteroid Itokawa provides insight into surface processes on airless bodies and will help in correlating remote sensing data with laboratory analysis of meteorites. Samples and Methods: We examined Itokawa samples RA-QD02-0042-01 and RA-QD-02-0042-02, ultramicrotomed sec-tions of a singular grain prepared by the Hayabusa sample cura-tion team. We analyzed these slices using a 200 keV JEOL 2010F transmission electron microscope (TEM) at Arizona State Uni-versity and a 200 keV JEOL 2500SE TEM at NASA JSC. Both field emission TEMs are equipped with energy-dispersive X-ray spectrometers (EDS) and scanning TEM (STEM) detectors. Results and Discussion: TEM observations reveal that the sectioned grain predominantly consists of a single crystal of low-Ca orthopyroxene, with subsidiary smaller regions of olivine, Fe-Ni sulfide, and Fe-Ni metal. EDS-spectrum imaging and high-resolution TEM (HRTEM) show local, nanocrystalline regions of the outermost 2 to 5 nm of the pyroxene are composed of an Fe-Mg-S-rich and Si- and O-depleted layer that is underlain by a 2- to 5-nm thick amorphous zone enriched in Si. These layers occur in multiple microtome slices and have uniform thicknesses. We also observe localized 'islands' of material on the surface of the pyroxene which HRTEM imaging indicates are amorphous and EDS measurements show are compositionally heterogeneous. A 10- to 60-nm thick partially amorphous zone occurs below the compositionally distinct rim. While this this zone is associated with the compositionally heterogeneous outer layer, it also occurs as a local stand-alone feature on the exterior rim of the grain. Ar-eas of the pyroxene grain rim also exhibit a vesicular texture. The TEM data indicate a complex history of space weather-ing for samples RA-QD02-0042-01 and -02. The outermost layer of nanocrystalline material with varied composition is consistent with previously suggested [3-4] chemical and structural pro-cessing by solar wind ions, with a possible additional role for im-pact vapor deposition [3-4]. The amorphous and compositionally distinct islands on the surface of this grain, similar to lunar glasses, suggest formation through vapor deposition via micrometeor-ite impact events. In comparison, the amorphization and vesicula-tion textures are likely a product of radiation damage from the solar wind. The depth and degree of amorphization, in conjunction with model calculations, will help provide an upper limit on exposure time for these particles.

Published
2013

13. FIB-TEM Investigations of Fe-NI-Sulfides in the CI Chondrites Alais and Orgueil

Author

Berger, Eve L, Lauretta, D. S, Zega, T. J, and Keller, L. P

Subjects
Lunar And Planetary Science And Exploration
Abstract

The CI chondrites are primitive meteorites with bulk compositions matching the solar photosphere for all but the lightest elements. They have been extensively aqueously altered, and are composed primarily of fine-grained phyllosilicate matrix material which is host to carbonates, sulfates, sulfides, and minor amounts of olivine and pyroxene. The alteration, while extensive, is heterogeneous. For example, CI-chondrite cubanite and carbonate grains differ on mm to sub-mm scales, demonstrating multiple aqueous episodes. CI-chondrite variability is also evidenced by degree of brecciation, abundance and size of coarse-grained phyllosilicates, olivine and pyroxene abundance, as well as Ni-content and size of sulfide grains. Our previous work revealed Orgueil sulfide grains with variable Ni-contents, metal:S ratios, crystal structures and textures. We continue to explore the variability of CI-chondrite pyrrhotite (Po, (FeNi)1-xS) and pentlandite (Pn, (Fe,Ni)9S8) grains. We investigate the microstructure of sulfides within and among CI-chondrite meteorites in order to place constraints on the conditions under which they formed.

Published
2013

14. Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Author

Hamilton, VE, Simon, AA, Christensen, PR, Reuter, DC, Clark, BE, Barucci, MA, Bowles, NE, Boynton, WV, Brucato, JR, Cloutis, EA, Jr, CHC, Hannah, KLD, Emery, JP, Enos, HL, Fornasier, S, Haberle, CW, Hanna, RD, Howell, ES, Kaplan, HH, Keller, LP, Lantz, C, Li, J-Y, Lim, LF, McCoy, TJ, Merlins, F, Nolan, MC, Praet, A, Rozitis, B, Sandford, SA, Schrader, DL, Thomas, CA, Zou, X-D, Lauretta, DS, Highsmith, DE, Small, J, Vokrouhlicky, D, Brown, E, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Bayron, J, Golubov, O, Sanchez, P, Stromberg, J, Hirabayashi, M, Hartzell, CM, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, McGraw, L, Ghent, R, Binzel, RP, Al Asad, MM, Johnson, CL, Philpott, L, Susorney, HCM, Ciceri, F, Hildebrand, AR, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Ferrone, S, Campins, H, Fernandez, Y, Chang, W, Cheuvront, A, Trang, D, Tachibana, S, Yurimoto, H, Poggiali, G, Pajola, M, Dotto, E, Epifani, EM, Crombie, MK, Izawa, MRM, De Leon, J, Licandro, J, Garcia, JLR, Clemett, S, Thomas-Keprta, K, Van Wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Chesley, SR, Elder, CM, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, JM, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Deshapriya, JDP, Fulchignoni, M, Hasselmann, P, Merlin, F, Bierhaus, EB, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Asphaug, E, Audi, E, Ballouz, R-L, Bandrowski, R, Becker, KJ, Becker, TL, Bendall, S, Bennett, CA, Bloomenthal, H, Blum, D, Brodbeck, J, Burke, KN, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, D'Aubigny, CYD, Dean, D, Dellagiustina, DN, Diallo, B, Drinnon, D, Drozd, K, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Golish, DR, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Hergenrother, CW, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Huettner, E, Janakus, A, Jones, J, Kareta, TR, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Maleszewski, CK, Malhotra, R, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Rizk, B, Roper, HL, Salazar, S, Schwartz, SR, Selznick, S, Shultz, N, Smith, PH, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CWV, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S-I, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Dworkin, JP, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, EM, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, RW, Le Corre, L, Molaro, JL, Palmer, EE, Siegler, MA, Tricarico, P, Weirich, JR, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Mehall, G, Rios, K, Franchi, I, Beddingfield, CB, Marshall, J, Brack, DN, French, AS, McMahon, JW, Scheeres, DJ, Jawin, ER, Russell, S, Killgore, M, Bottke, WF, Walsh, KJ, Bandfield, JL, Clark, BC, Chodas, M, Lambert, M, Masterson, RA, Daly, MG, Freemantle, J, Seabrook, JA, Barnouin, OS, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Perry, ME, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo, M, Libourel, G, Michel, P, Ryan, A, Thuillet, F, Marty, B, Team, O-R, Southwest Research Institute [Boulder] (SwRI), ASU School of Earth and Space Exploration (SESE), Arizona State University [Tempe] (ASU), NASA Goddard Space Flight Center (GSFC), Ithaca College, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Department of Geography [Winnipeg], University of Winnipeg, Department of Physics, Rowan University, Glassboro, Rowan University, Department of Earth and Planetary Sciences [Knoxville], The University of Tennessee [Knoxville], Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin [Austin], The Swiss Light Source (SLS) (SLS-PSI), Paul Scherrer Institute (PSI), NASA Johnson Space Center (JSC), NASA, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris-Sud - Paris 11 (UP11), Planetary Science Institute [Tucson] (PSI), Smithsonian Institution, National Museum of Natural History, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), The Open University [Milton Keynes] (OU), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Center for Meteorite Studies [Tempe], Northern Arizona University [Flagstaff], Centre de Mise en Forme des Matériaux (CEMEF), Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), University of Oxford [Oxford], Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris Sud Orsay, and MINES ParisTech - École nationale supérieure des mines de Paris

Subjects
Mineral hydration, Thermal infrared, 010504 meteorology & atmospheric sciences, Comets and Kuiper belt, Astronomy and Astrophysics, Mineralogy, 01 natural sciences, Article, Asteroids, Astrobiology, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI]Engineering Sciences [physics], Asteroid, Chondrite, Meteoritics, 0103 physical sciences, Early solar system, Spectral data, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract

著者人数: 33名ほか (The OSIRIS-REx Team: 所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): Van wal, S; 吉川, 真; 渡邊, 誠一郎), Number of authors: 33 and The OSIRIS-REx Team (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Van wal, S; Yoshikawa, Makoto; Watanabe, Sei-icihro), Accepted: 2019-02-12, 資料番号: SA1190036000

Published
2019
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15. The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

Author

Scheeres, DJ, McMahon, JW, French, AS, Brack, DN, Chesley, SR, Farnocchia, D, Takahashi, Y, Leonard, JM, Geeraert, J, Page, B, Antreasian, P, Getzandanner, K, Rowlands, D, Mazarico, EM, Small, J, Highsmith, DE, Moreau, M, Emery, JP, Rozitis, B, Hirabayashi, M, Sanchez, P, Van Wal, S, Tricarico, P, Ballouz, R-L, Johnson, CL, Asad, MM, Susorney, HCM, Barnouin, OS, Daly, MG, Seabrook, JA, Gaskell, RW, Palmer, EE, Weirich, JR, Walsh, KJ, Jawin, ER, Bierhaus, EB, Michel, P, Bottke, WF, Nolan, MC, Jr, CHC, Lauretta, DS, Vokrouhlicky, D, Bowles, NE, Brown, E, Hanna, KLD, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, DL, Bayron, J, Golubov, O, Stromberg, J, Hartzell, CM, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, McGraw, L, Ghent, R, Binzel, RP, Philpott, L, Cloutis, EA, Hanna, RD, Ciceri, F, Hildebrand, AR, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Clark, BE, Ferrone, S, Thomas, CA, Campins, H, Fernandez, Y, Chang, W, Cheuvront, A, Trang, D, Tachibana, S, Yurimoto, H, Brucato, JR, Poggiali, G, Pajola, M, Dotto, E, Epifani, EM, Crombie, MK, Lantz, C, Izawa, MRM, De Leon, J, Licandro, J, Garcia, JL, Clemett, S, Thomas-Keprta, K, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Elder, CM, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Velez, D, Yetter, K, Thayer, C, Adam, C, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Hoffman, J, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Barucci, MA, Deshapriya, JDP, Fornasier, S, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Asphaug, E, Audi, E, Bandrowski, R, Becker, KJ, Becker, TL, Bendall, S, Bennett, CA, Bloomenthal, H, Blum, D, Boynton, WV, Brodbeck, J, Burke, KN, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, D'Aubigny, CYD, Dean, D, Dellagiustina, DN, Diallo, B, Drinnon, D, Drozd, K, Enos, HL, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Golish, DR, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Hergenrother, CW, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Howell, ES, Huettner, E, Janakus, A, Jones, J, Kareta, TR, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Maleszewski, CK, Malhotra, R, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Rizk, B, Roper, HL, Salazar, S, Schwartz, SR, Selznick, S, Shultz, N, Smith, PH, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CWV, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S-I, Sandford, SA, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Dworkin, JP, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Lim, LF, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mink, R, Moore, W, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Reuter, DC, Rhoads, L, Rieger, S, Sallitt, D, Scroggins, A, Shaw, G, Simon, AA, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, LP, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Le Corre, L, Li, J-Y, Molaro, JL, Siegler, MA, Zou, X-D, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Christensen, PR, Haberle, CW, Mehall, G, Rios, K, Franchi, I, Beddingfield, CB, Marshall, J, McCoy, TJ, Russell, S, Killgore, M, Hamilton, VE, Kaplan, HH, Bandfield, JL, Clark, BC, Chodas, M, Lambert, M, Masterson, RA, Freemantle, J, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Perry, ME, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo', M, Libourel, G, Ryan, A, Thuillet, F, Marty, B, Team, The OSIRIS-REx, USDA Agricultural Research Service [Maricopa, AZ] (USDA), United States Department of Agriculture (USDA), Dipartimento di Matematica, University of Pisa - Università di Pisa, Department of Geophysics [Sendai], Tohoku University [Sendai], KinetX Aerospace Inc., Institut de Recherche Interdisciplinaire sur les enjeux Sociaux - sciences sociales, politique, santé (IRIS), Université Paris 13 (UP13)-École des hautes études en sciences sociales (EHESS)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris sciences et lettres (PSL), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), The Open University [Milton Keynes] (OU), National Institute of Polar Research [Tokyo] (NiPR), IHU-LIRYC, Université Bordeaux Segalen - Bordeaux 2-CHU Bordeaux [Bordeaux], Planetary Science Institute [Tucson] (PSI), Institute of Northern Engineering, 455 Duckering Bldg, Centre de Mise en Forme des Matériaux (CEMEF), Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), ANR-15-IDEX-0001,UCA JEDI,Idex UCA JEDI(2015), Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Sorbonne Paris Cité (USPC)-École des hautes études en sciences sociales (EHESS)-Université Paris 13 (UP13), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and MINES ParisTech - École nationale supérieure des mines de Paris

Subjects
010504 meteorology & atmospheric sciences, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Physics, Spin rate, Equator, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy and Astrophysics, Geophysics, Astronomy and planetary science, biology.organism_classification, 01 natural sciences, Article, [SPI]Engineering Sciences [physics], Engineering, Asteroid, 0103 physical sciences, Roche lobe, Osiris, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract

著者人数: 41名ほか (The OSIRIS-REx Team: 所属. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS): Van wal, Stefaan; 吉川, 真; 渡邊, 誠一郎), Number of authors: 41 and The OSIRIS-REx Team (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS): Yoshikawa, Makoto; Watanabe, Sei-ichiro), Accepted: 2019-02-11, 資料番号: SA1180379000

Published
2019
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17. Nanometer-Scale Measurements of Ferrous-Ferric Ratios in Chondritic Cronstedtite

Author

Zega, T. J, Garvie, L. A. J, and Buseck, P. R

Subjects
Lunar And Planetary Science And Exploration
Abstract

We have determined the ferrous-ferric ratio in chondritic cronstedtite at the nanometer scale using electron energy-loss spectroscopy and transmission electron microscopy. Additional information is contained in the original extended abstract.

Published
2002

22. Opaque Minerals in the Matrix of the Bishunpur (LL3.1) Chondrite: Constraints on the Chondrule Formation Environment

Author

Lauretta, D. S, Buseck, P. R, and Zega, T. J

Subjects
Lunar And Planetary Science And Exploration
Abstract

The chemistry and mineralogy of a group of opaque mineral assemblages in the matrix of the Bishunpur LL3.1 ordinary chondrite provide insight into the nebular environment in which they formed. The assemblages consist of a kamacite (Fe,Ni) core that is rimmed by troilite (FeS) and fayalite (Fe2Si04). Accessory phases in the rims include silica (Si02), chromite (FeCr204), whitlockite (Ca3(P04)2), maricite (FeNaP04), magnetite (Fe304), and tetrataenite (FeNi). We suggest that the metal melted in and equilibrated with an igneous chondrule under high- temperature, reducing conditions. In this environment the molten alloys incorporated varied amounts of Si, Ni, P, Cr, and Co, depending on the oxygen fugacity and temperature of the melt. Some of the metal was subsequently expelled from the chondrule interiors into the surrounding nebular gas. As the temperature dropped, the alloy solidified and volatile elements corroded the metal. The main reaction products were troilite and fayalite. Thermodynamic equilibrium calculations are used to constrain the conditions under which these two phases can form simultaneously in the solar nebula. Kinetic factors are used to place a lower limit on the formation temperature. We determine that the metal corroded between 1173 and 1261 K at a total pressure in the range of 1025.0 to 1024.1 bars and a dust/gas ratio of 302 to 355 x relative to solar composition. These conditions are consistent with our model that the metal corroded in a dust- rich region of the solar nebula that was cooling after a chondrule formation event.

Published
2001
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25. The operational environment and rotational acceleration of asteroid (101955) Bennu from OSIRIS-REx observations

Author

Hergenrother, CW, Maleszewski, CK, Nolan, MC, Li, J-Y, d'Aubigny, CYD, Shelly, FC, Howell, ES, Kareta, TR, Izawa, MRM, Barucci, MA, Bierhaus, EB, Campins, H, Chesley, SR, Clark, BE, Christensen, EJ, DellaGiustina, DN, Fornasier, S, Golish, DR, Hartzell, CM, Rizk, B, Scheeres, DJ, Smith, PH, Zou, X-D, Lauretta, DS, Highsmith, DE, Small, J, Vokrouhlicky, D, Bowles, NE, Brown, E, Hanna, KLD, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, DL, Bayron, J, Golubov, O, Sanchez, P, Stromberg, J, Hirabayashi, M, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, Emery, JP, McGraw, L, Ghent, R, Binzel, RP, Al Asad, MM, Johnson, CL, Philpott, L, Susorney, HCM, Cloutis, EA, Hanna, RD, Connolly, HC, Ciceri, F, Hildebrand, AR, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Ferrone, S, Thomas, CA, Fernandez, Y, Chang, W, Cheuvront, A, Trang, D, Tachibana, S, Yurimoto, H, Brucato, JR, Poggiali, G, Pajola, M, Dotto, E, Epifani, EM, Crombie, MK, Lantz, C, de Leon, J, Licandro, J, Rizos Garcia, JL, Clemett, S, Thomas-Keprta, K, Van Wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Elder, CM, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, JM, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Deshapriya, JDP, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Asphaug, E, Audi, E, Ballouz, R-L, Bandrowski, R, Becker, KJ, Becker, TL, Bendall, S, Bennett, CA, Bloomenthal, H, Blum, D, Boynton, W, Brodbeck, J, Burke, KN, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, Dean, D, Diallo, B, Drinnon, D, Drozd, K, Enos, HL, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Huettner, E, Janakus, A, Jones, J, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Malhotra, R, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Roper, HL, Salazar, S, Schwartz, SR, Selznick, S, Shultz, N, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CW, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S, Sandford, SA, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Dworkin, JP, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Lim, LF, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, EM, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Reuter, DC, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Simon, AA, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, LP, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, RW, Le Corre, L, Molaro, JL, Palmer, EE, Siegler, MA, Tricarico, P, Weirich, JR, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Christensen, PR, Haberle, CW, Mehall, G, Rios, K, Franchi, I, Rozitis, B, Beddingfield, CB, Marshall, J, Brack, DN, French, AS, McMahon, JW, Jawin, ER, McCoy, TJ, Russell, S, Killgore, M, Bottke, WF, Hamilton, VE, Kaplan, HH, Walsh, KJ, Bandfield, JL, Clark, BC, Chodas, M, Lambert, M, Masterson, RA, Daly, MG, Freemantle, J, Seabrook, JA, Barnouin, OS, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Perry, ME, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo, M, Libourel, G, Michel, P, Ryan, A, Thuillet, F, Marty, B, Hergenrother, CW, Maleszewski, CK, Nolan, MC, Li, J-Y, d'Aubigny, CYD, Shelly, FC, Howell, ES, Kareta, TR, Izawa, MRM, Barucci, MA, Bierhaus, EB, Campins, H, Chesley, SR, Clark, BE, Christensen, EJ, DellaGiustina, DN, Fornasier, S, Golish, DR, Hartzell, CM, Rizk, B, Scheeres, DJ, Smith, PH, Zou, X-D, Lauretta, DS, Highsmith, DE, Small, J, Vokrouhlicky, D, Bowles, NE, Brown, E, Hanna, KLD, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, DL, Bayron, J, Golubov, O, Sanchez, P, Stromberg, J, Hirabayashi, M, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, Emery, JP, McGraw, L, Ghent, R, Binzel, RP, Al Asad, MM, Johnson, CL, Philpott, L, Susorney, HCM, Cloutis, EA, Hanna, RD, Connolly, HC, Ciceri, F, Hildebrand, AR, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Ferrone, S, Thomas, CA, Fernandez, Y, Chang, W, Cheuvront, A, Trang, D, Tachibana, S, Yurimoto, H, Brucato, JR, Poggiali, G, Pajola, M, Dotto, E, Epifani, EM, Crombie, MK, Lantz, C, de Leon, J, Licandro, J, Rizos Garcia, JL, Clemett, S, Thomas-Keprta, K, Van Wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Elder, CM, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, JM, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Deshapriya, JDP, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Asphaug, E, Audi, E, Ballouz, R-L, Bandrowski, R, Becker, KJ, Becker, TL, Bendall, S, Bennett, CA, Bloomenthal, H, Blum, D, Boynton, W, Brodbeck, J, Burke, KN, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, Dean, D, Diallo, B, Drinnon, D, Drozd, K, Enos, HL, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Huettner, E, Janakus, A, Jones, J, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Malhotra, R, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Roper, HL, Salazar, S, Schwartz, SR, Selznick, S, Shultz, N, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CW, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S, Sandford, SA, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Dworkin, JP, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Lim, LF, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, EM, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Reuter, DC, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Simon, AA, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, LP, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, RW, Le Corre, L, Molaro, JL, Palmer, EE, Siegler, MA, Tricarico, P, Weirich, JR, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Christensen, PR, Haberle, CW, Mehall, G, Rios, K, Franchi, I, Rozitis, B, Beddingfield, CB, Marshall, J, Brack, DN, French, AS, McMahon, JW, Jawin, ER, McCoy, TJ, Russell, S, Killgore, M, Bottke, WF, Hamilton, VE, Kaplan, HH, Walsh, KJ, Bandfield, JL, Clark, BC, Chodas, M, Lambert, M, Masterson, RA, Daly, MG, Freemantle, J, Seabrook, JA, Barnouin, OS, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Perry, ME, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo, M, Libourel, G, Michel, P, Ryan, A, Thuillet, F, and Marty, B

Abstract

During its approach to asteroid (101955) Bennu, NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft surveyed Bennu's immediate environment, photometric properties, and rotation state. Discovery of a dusty environment, a natural satellite, or unexpected asteroid characteristics would have had consequences for the mission's safety and observation strategy. Here we show that spacecraft observations during this period were highly sensitive to satellites (sub-meter scale) but reveal none, although later navigational images indicate that further investigation is needed. We constrain average dust production in September 2018 from Bennu's surface to an upper limit of 150 g s-1 averaged over 34 min. Bennu's disk-integrated photometric phase function validates measurements from the pre-encounter astronomical campaign. We demonstrate that Bennu's rotation rate is accelerating continuously at 3.63 ± 0.52 × 10-6 degrees day-2, likely due to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, with evolutionary implications.

Published
2019

29. Extreme 13C,15N and 17O isotopic enrichment in the young planetary nebula K4-47.

Author

Schmidt, D. R., Woolf, N. J., Zega, T. J., and Ziurys, L. M.

Abstract

Carbon, nitrogen and oxygen are the three most abundant elements in the Galaxy after hydrogen and helium. Whereas hydrogen and helium were created in the Big Bang, carbon, nitrogen and oxygen arise from nucleosynthesis in stars. Of particular interest1,2 are the isotopic ratios 12C/13C, 14N/15N and 16O/17O because they are effective tracers of nucleosynthesis and help to benchmark the chemical processes that occurred in primitive interstellar material as it evolved into our Solar System3. However, the origins of the rare isotopes 15N and 17O remain uncertain, although novae and very massive stars that explode as supernovae are postulated4-6 to be the main sources of 15N. Here we report millimetre-wavelength observations of the young bipolar planetary nebula K4-47 that indicate another possible source for these isotopes. We identify various carbon-bearing molecules in K4-47 that show that this object is carbon-rich, and find unusually high enrichment in rare carbon (13C), oxygen (17O) and nitrogen (15N) isotopes: 12C/13C = 2.2 ± 0.8, 16O/17O = 21.4 ± 10.3 and 14N/15N = 13.6 ± 6.5 (uncertainties are three standard deviations); for comparison, the corresponding solar ratios7 are 89.4 ± 0.2, 2,632 ± 7 and 435 ± 57. One possible interpretation of these results is that K4-47 arose from a J-type asymptotic giant branch star that underwent a helium-shell flash (an explosive nucleosynthetic event that converts large quantities of helium to carbon and other elements), enriching the resulting planetary nebula in 15N and 17O and creating its bipolar geometry. Other possible explanations are that K4-47 is a binary system or that it resulted from a white dwarf merger, as has been suggested for object CK Vul8. These results suggest that nucleosynthesis of carbon, nitrogen and oxygen is not well understood and that the classification of certain stardust grains must be reconsidered. Millimetre-wavelength observations of the bipolar planetary nebula K4-47 show very high abundances of the rare isotopes 13C, 15N and 17O, providing clues about the possible origin of the nebula. [ABSTRACT FROM AUTHOR]

Published
2018
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30. Secondary ion mass spectrometry and x-ray absorption near-edge structure spectroscopy of isotopically anomalous organic matter from CR1 chondrites GRO 95577

Author

Busemann, H., Zega, T. J., Alexander, C. M. O'D., Cody, G. D., Kilcoyne, A. L. D., Nittler, L. R., Stroud, R. M., and Yabuta, H.

Abstract

We located interstellar organics from a CR1 chondrite with NanoSIMS and analyzed FIB-extracted sections with XANES. D-rich material appears not associated with a functional group, whereas 15N-rich matter shows some affinity to nitrile functionality.

Published
2007

31. Correlated analyses of D- and 15N-rich carbon grains from CR2 chondrite EET 92042

Author

Busemann, H., Alexander, C. M. O'D., Nittler, L. R., Zega, T. J., Stroud, R. M., Bajt, S., Cody, G. D., and Yabuta, H.

Abstract

Extract from introduction: Insoluble organic matter (IOM) and matrix from primitive carbonaceous chondrites carry isotope enrichments (?D?20000', ?15N?3200�) that are comparable to those in interplanetary dust particles [1, this work]. Hence, primitive organics that formed in the protosolar cloud (PSC) – or maybe in the cold outer regions of the protoplanetary disk – survived accretion and planetary processing on the asteroids, the parent bodies of the chondrites.

Published
2006

32. Mineralogy and petrology of Comet Wild-2 nucleus samples - Final results of the preliminary examination team

Author

Zolensky, M, Bland, P, Bradley, J, Brearley, A, Brennan, S, Bridges, J, Brownlee, D, Butterworth, A, Dai, ZR, Ebel, D, Genge, M, Gounelle, M, Graham, G, Grossman, J, Grossman, L, Harvey, R, Ishii, H, Kearsley, A, Keller, L, Krot, A, Langenhorst, F, Lanzirotti, A, Leroux, H, Matrajt, G, Messenger, K, Mikouchi, T, Nakamura, T, Ohsumi, K, Okudaira, K, Perronnet, M, Rietmeijer, F, Simon, S, Stephan, T, Stroud, R, Taheri, M, Tomeoka, K, Toppani, A, Tsou, P, Tsuchiyama, A, Velbel, M, Weber, I, Weisberg, M, Westphal, A, Yano, H, Zega, T, and Stardust Mineralogy Petrology

Abstract

Accepted version

Published
2006

34. Correlated Microscale Isotope and Scanning Transmission X-Ray Analyses of Isotopically Anomalous Organic Matter from the CR2 Chondrite EET 92042

Author

Busemann, H., Alexander, C. M. O'D., Nittler, L. R., Zega, T. J., Stroud, R. M., Cody, G. D., Yabuta, H., and Hoppe, P.

Abstract

We discuss correlated examinations of organic matter from the CR2 chondrite EET 92042, using SIMS, STXM and other methods. We found a large, isotopically highly anomalous region of probable presolar origin that is C- and 13C-poor and 15N-rich.

Published
2006

36. Band-Edge Excitons in PbSe Nanocrystals and Nanorods

Author

NAVAL RESEARCH LAB WASHINGTON DC, Tischler, J. G., Kennedy, T. A., Glaser, E. R., Efros, A. L., Foos, E. E., Boercker, J. E., Zega, T. J., Stroud, R. M., Erwin, S. C., NAVAL RESEARCH LAB WASHINGTON DC, Tischler, J. G., Kennedy, T. A., Glaser, E. R., Efros, A. L., Foos, E. E., Boercker, J. E., Zega, T. J., Stroud, R. M., and Erwin, S. C.

Abstract

We investigate the fine structure of band-edge excitons in PbSe nanocrystals and nanorods using circularly polarized magnetophotoluminescence and optically detected magnetic resonance and, based on the results, propose a singlet-triplet model of exciton photoluminescence from nondegenerate conduction and valence bands. From the data and model we extract g-factors for electrons and holes of +1.2 and +0.8, respectively. The splitting of the triplet ground state, which is responsible for the low-temperature photoluminescence, is 88 eV for nanorods, and less than 20 eV for nanocrystals. The intervalley splitting of the electron and hole levels in the nanocrystals is much larger than the electron-hole exchange interaction., Published in Physical Review B, v82 n245303, p1-6, 2010.

Published
2010

37. Mineralogy and petrology of comet 81P/wild 2 nucleus samples

Author

Zolensky, M., Zega, T., Yano, H., Wirick, S., Westphal, A., Weisberg, M., Weber, I., Warren, J., Velbel, M., Tsuchiyama, A., Tsou, P., Toppani, A., Tomioka, N., Tomeoka, K., Teslich, N., Taheri, M., Susini, J., Stroud, R., Stephan, T., Stadermann, F., Snead, C., Simon, S., Simionovici, A., See, T., Robert, F., Rietmeijer, F., Rao, W., Perronnet, M., Papanastassiou, D., Okudaira, K., Ohsumi, K., Ohnishi, I., Nakamura-Messenger, K., Nakamura, T., Mostefaoui, S., Mikouchi, T., Meibom, A., Matrajt, G., Marcus, M., Leroux, H., Lemelle, L., Le, L., Lanzirotti, A., Langenhorst, F., Krot, A., Keller, L., Kearsley, A., Joswiak, D., Jacob, D., Ishii, H., Harvey, R., Hagiya, K., Grossman, L., Grossman, J., Graham, G., Gounelle, M., Gillet, P., Genge, M., Flynn, G., Ferroir, T., Fallon, S., Ebel, D., Dai, Z., Cordier, P., Clark, B., Chi, M., Butterworth, A., Brownlee, D., Bridges, J., Brennan, S., Brearley, A., Bradley, J., Bleuet, P., Bland, Phil, Bastien, R., Zolensky, M., Zega, T., Yano, H., Wirick, S., Westphal, A., Weisberg, M., Weber, I., Warren, J., Velbel, M., Tsuchiyama, A., Tsou, P., Toppani, A., Tomioka, N., Tomeoka, K., Teslich, N., Taheri, M., Susini, J., Stroud, R., Stephan, T., Stadermann, F., Snead, C., Simon, S., Simionovici, A., See, T., Robert, F., Rietmeijer, F., Rao, W., Perronnet, M., Papanastassiou, D., Okudaira, K., Ohsumi, K., Ohnishi, I., Nakamura-Messenger, K., Nakamura, T., Mostefaoui, S., Mikouchi, T., Meibom, A., Matrajt, G., Marcus, M., Leroux, H., Lemelle, L., Le, L., Lanzirotti, A., Langenhorst, F., Krot, A., Keller, L., Kearsley, A., Joswiak, D., Jacob, D., Ishii, H., Harvey, R., Hagiya, K., Grossman, L., Grossman, J., Graham, G., Gounelle, M., Gillet, P., Genge, M., Flynn, G., Ferroir, T., Fallon, S., Ebel, D., Dai, Z., Cordier, P., Clark, B., Chi, M., Butterworth, A., Brownlee, D., Bridges, J., Brennan, S., Brearley, A., Bradley, J., Bleuet, P., Bland, Phil, and Bastien, R.

Published
2006

38. Comet 81P/Wild 2 Under a Microscope

Author

Brownlee, D., Tsou, P., Aléon, J., Alexander, C., Araki, T., Bajt, S., Baratta, G., Bastien, R., Bland, Phil, Bleuet, P., Borg, J., Bradley, J., Brearley, A., Brenker, F., Brennan, S., Bridges, J., Browning, N., Brucato, J., Bullock, E., Burchell, M., Busemann, H., Butterworth, A., Chaussidon, M., Cheuvront, A., Chi, M., Cintala, M., Clark, B., Clemett, S., Cody, G., Colangeli, L., Cooper, G., Cordier, P., Daghlian, C., Dai, Z., D’Hendecourt, L., Djouadi, Z., Dominguez, G., Duxbury, T., Dworkin, J., Ebel, D., Economou, T., Fakra, S., Fairey, S., Fallon, S., Ferrini, G., Ferroir, T., Fleckenstein, H., Floss, C., Flynn, G., Franchi, I., Fries, M., Gainsforth, Z., Gallien, J., Genge, M., Gilles, M., Gillet, P., Gilmour, J., Glavin, D., Gounelle, M., Grady, M., Graham, G., Grant, P., Green, S., Grossemy, F., Grossman, L., Grossman, J., Guan, Y., Hagiya, K., Harvey, R., Heck, P., Herzog, G., Hoppe, P., Hörz, F., Huth, J., Hutcheon, I., Ignatyev, K., Ishii, H., Ito, M., Jacob, D., Jacobsen, C., Jacobsen, S., Jones, S., Joswiak, D., Jurewicz, A., Kearsley, A., Keller, L., Khodja, H., Kilcoyne, A., Kissel, J., Krot, A., Langenhorst, F., Lanzirotti, A., Le, L., Leshin, L., Leitner, J., Lemelle, L., Leroux, H., Liu, M., Luening, K., Lyon, I., MacPherson, G., Marcus, M., Marhas, K., Marty, B., Matrajt, G., McKeegan, K., Meibom, A., Mennella, V., Messenger, K., Messenger, S., Mikouchi, T., Mostefaoui, S., Nakamura, T., Newville, M., Nittler, L., Ohnishi, I., Ohsumi, K., Okudaira, K., Papanastassiou, D., Palma, R., Palumbo, M., Pepin, R., Perkins, D., Perronnet, M., Pianetta, P., Rao, W., Rietmeijer, F., Robert, F., Rost, D., Rotundi, A., Ryan, R., Sandford, S., Schwandt, C., See, T., Schlutter, D., Sheffield-Parker, J., Simionovici, A., Simon, S., Sitnitsky, I., Snead, C., Stephan, T., Stadermann, F., Steele, A., Stroud, R., Susini, J., Sutton, S., Suzuki, Y., Taheri, M., Taylor, S., Teslich, N., Tomeoka, K., Tomioka, N., Toppani, A., Trigo-Rodríguez, J., Troadec, D., Tsuchiyama, A., Tuzzolino, A., Tyliszczak, T., Uesugi, K., Velbel, M., Vellenga, J., Vicenzi, E., Vincze, L., Warren, J., Weber, I., Weisberg, M., Westphal, A., Wirick, S., Wooden, D., Wopenka, B., Wozniakiewicz, P., Wright, I., Yabuta, H., Yano, H., Young, E., Zare, R., Zega, T., Ziegler, K., Zimmerman, L., Zinner, E., Zolensky, M., Brownlee, D., Tsou, P., Aléon, J., Alexander, C., Araki, T., Bajt, S., Baratta, G., Bastien, R., Bland, Phil, Bleuet, P., Borg, J., Bradley, J., Brearley, A., Brenker, F., Brennan, S., Bridges, J., Browning, N., Brucato, J., Bullock, E., Burchell, M., Busemann, H., Butterworth, A., Chaussidon, M., Cheuvront, A., Chi, M., Cintala, M., Clark, B., Clemett, S., Cody, G., Colangeli, L., Cooper, G., Cordier, P., Daghlian, C., Dai, Z., D’Hendecourt, L., Djouadi, Z., Dominguez, G., Duxbury, T., Dworkin, J., Ebel, D., Economou, T., Fakra, S., Fairey, S., Fallon, S., Ferrini, G., Ferroir, T., Fleckenstein, H., Floss, C., Flynn, G., Franchi, I., Fries, M., Gainsforth, Z., Gallien, J., Genge, M., Gilles, M., Gillet, P., Gilmour, J., Glavin, D., Gounelle, M., Grady, M., Graham, G., Grant, P., Green, S., Grossemy, F., Grossman, L., Grossman, J., Guan, Y., Hagiya, K., Harvey, R., Heck, P., Herzog, G., Hoppe, P., Hörz, F., Huth, J., Hutcheon, I., Ignatyev, K., Ishii, H., Ito, M., Jacob, D., Jacobsen, C., Jacobsen, S., Jones, S., Joswiak, D., Jurewicz, A., Kearsley, A., Keller, L., Khodja, H., Kilcoyne, A., Kissel, J., Krot, A., Langenhorst, F., Lanzirotti, A., Le, L., Leshin, L., Leitner, J., Lemelle, L., Leroux, H., Liu, M., Luening, K., Lyon, I., MacPherson, G., Marcus, M., Marhas, K., Marty, B., Matrajt, G., McKeegan, K., Meibom, A., Mennella, V., Messenger, K., Messenger, S., Mikouchi, T., Mostefaoui, S., Nakamura, T., Newville, M., Nittler, L., Ohnishi, I., Ohsumi, K., Okudaira, K., Papanastassiou, D., Palma, R., Palumbo, M., Pepin, R., Perkins, D., Perronnet, M., Pianetta, P., Rao, W., Rietmeijer, F., Robert, F., Rost, D., Rotundi, A., Ryan, R., Sandford, S., Schwandt, C., See, T., Schlutter, D., Sheffield-Parker, J., Simionovici, A., Simon, S., Sitnitsky, I., Snead, C., Stephan, T., Stadermann, F., Steele, A., Stroud, R., Susini, J., Sutton, S., Suzuki, Y., Taheri, M., Taylor, S., Teslich, N., Tomeoka, K., Tomioka, N., Toppani, A., Trigo-Rodríguez, J., Troadec, D., Tsuchiyama, A., Tuzzolino, A., Tyliszczak, T., Uesugi, K., Velbel, M., Vellenga, J., Vicenzi, E., Vincze, L., Warren, J., Weber, I., Weisberg, M., Westphal, A., Wirick, S., Wooden, D., Wopenka, B., Wozniakiewicz, P., Wright, I., Yabuta, H., Yano, H., Young, E., Zare, R., Zega, T., Ziegler, K., Zimmerman, L., Zinner, E., and Zolensky, M.

Published
2006

39. Effects of the Heteroepitaxial Interface on Spin Injection in Fe/AlGaAs

Author

Zega, T. J., Stroud, R. M., Hanbicki, A. T., Kioseoglou, G., Van't Erve, O. M. J., Li, C. H., Jonker, B. T., Itskos, Grigorios, Mallory, R., Yasar, M., Petrou, Athos Chariton, and Itskos, Grigorios [0000-0003-3971-3801]

Subjects
Materials science, business.industry, Interface (Java), Optoelectronics, business, Spin injection, Instrumentation
Abstract

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

Published
2004
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43. Band-edge excitons in PbSe nanocrystals and nanorods

Author

Tischler, J. G., primary, Kennedy, T. A., additional, Glaser, E. R., additional, Efros, Al. L., additional, Foos, E. E., additional, Boercker, J. E., additional, Zega, T. J., additional, Stroud, R. M., additional, and Erwin, S. C., additional

Published
2010
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47. ALTERATION OF P-BEARING PHASES IN ALLAN HILLS 77307 AND MURCHISON METEORITES.

Author

Benner, M. C., Zega, T. J., and Ziurys, L. M.

Subjects
*APATITE, *CHROMITE, *METEORITES, *SCANNING electron microscopes, *NEUTRON capture, *TRANSMISSION electron microscopes, *ELECTRON probe microanalysis, *MARTIAN meteorites
Abstract

Introduction: Despite its biological and geological importance, it is unclear in what form phosphorus is delivered to the early solar nebula and how it is subsequently transformed. P is synthesized by neutron capture on silicon in massive stars (= 8 M?) and core-collapse supernovae (SNe) [1]. In the gas phase, P was reported in molecular form as PO, PN, CP, CCP, HCP, and PH3 [2] in circumstellar envelopes. In the solid state, the most abundant P-bearing minerals in meteorites are schreibersite ((Fe, Ni)3P), apatite (Ca5(PO4)3(Cl, F, OH)), and merrillite (Ca9NaMg(PO4)7) [3]. Equilibrium thermodynamic modeling of a cooling gas of solar composition predicts schreibersite to condense at ~1225 K and apatite/merrillite at ~700 K (10-4 bar) [4]. Here we report on the carrier phases of P in Allan Hills (ALHA) 77307 and Murchison, which represent pristine CO 3.0 and aqueously altered CM 2.0 chondrites, respectively. Our goal is to understand how P was delivered to the early solar nebula, in what forms it condensed into the solid state, how it subsequently evolved on meteorite parent bodies, and in what form it was delivered to the early Earth. Samples and Methods: Petrographic thin sections of Murchison and ALHA 77307 from the UofA collection were analyzed in the Kuiper Materials Imaging and Characterization Facility located at the Lunar and planetary Laboratory, University of Arizona. We mapped each sample for P, O, C, Fe, and S using the Cameca SX-100 electron microprobe. P-bearing regions of interest (ROIs) were down selected based on location, representative microstructure, and element maps acquired using the energy dispersive X-ray spectrometer (EDS) on the Hitachi S4800 scanning electron microscope (SEM). Chosen ROIs were cross sectioned, extracted, and thinned to electron transparency (=100 nm) using a ThermoFisher Helios NanoLab 660 G3 focused-ion-beam scanning electron microscope (FIB-SEM) with methods previously described [5]. FIB sections were analyzed for crystal chemistry and structure using a 200 keV Hitachi HF5000 Scanning Transmission Electron Microscope (S/TEM) equipped with a 3rd-order spherical aberration corrector for S/TEM mode, bright field (BF)- and dark field (DF)-STEM detectors, and an Oxford Instruments XMaxN 100 TLE EDS system with dual 100 mm2 windowless silicon-drift detectors (O = 2.0 sr). Results and discussion: We identified 29 P-bearing ROIs in ALHA 77307 and chose ROI 2 based on its isolated location in the matrix, making it a candidate for nebular dust. We extracted a FIB section measuring ~6.22 µm × 4.91 µm and thinned it to electron transparency. STEM-HAADF and BF images reveal a ~ 6 µm × 3 µm single crystal of schreibersite with a layered rim. The inner layer of the rim is composed of an Fe- and Na-bearing phosphate, whereas the outer layer is composed of Cr-bearing oxide, tentatively identified as ferroalluaudite (NaFe3PO12) and chromite (FeCr2O4), respectively. The matrix material of ALHA 77307 is heterogenous and largely consists of anhydrous minerals including olivine, pyroxene, and magnetite. In comparison, we identified 13 P-bearing ROIs in Murchison. ROI 3 of Murchison is ~170 µm long matrix grain that was selected based on SEM-EDS results maps, which reveal a P-bearing Fe-Ni sulfide phase. We extracted a FIB section from the interior of the grain. STEM-BF and HAADF imaging and STEM-EDS reveal that a Ca-phosphate phase occurs between grains of a P-bearing Fe-Ni sulfide. The P-bearing sulfide phase is nanocrystalline, as revealed by SAED patterns. Thermodynamic calculations that model a cooling gas of solar composition predict that schreibersite, apatite, and merrillite form in the solar nebula from gas-solid reactions [4,6]. The model includes nine gas species: P, P2, P4O6, PH, PH2, PH3, PN, PO, and PS [6]. The solid phases predicted in [4] are ideal solid solutions and represent endmember compositions. The single crystal of schreibersite located in the matrix of ALHA 77307 is generally consistent with equilibrium predictions. The presence of ferroalluaudite, chromite, and magnetite surrounding the schreibersite grain in ALHA 77307 is suggestive of a nebular metasomatic reaction of schreibersite. In comparison, P-bearing Fe-Ni sulfides were previously reported in CM 2.0 and CM 1/2 chondrites [9-11]. Such sulfides are not consistent with previous thermodynamic predictions [4,6], and are likely produced by secondary alteration on the parent body [10]. [ABSTRACT FROM AUTHOR]

Published
2022

48. PENTLANDITE IN CHONDRITES: A COMPOSITIONAL INDICATOR OF OXYGEN FUGACITY.

Author

Schrader, D. L., Zega, T. J., Davidson, J., McCoy, T. J., and Domanik, K. J.

Subjects
*CARBONACEOUS chondrites (Meteorites), *OXYGEN detectors, *CHONDRITES, *SMALL solar system bodies, *ASTEROIDS, *PLANETESIMALS, *PROTOPLANETARY disks, *FUGACITY
Abstract

Introduction: Fe-sulfides are ubiquitous in chondrites and are sensitive indicators of formation and alteration conditions in the protoplanetary disk and small Solar System bodies [e.g., 1-14]. We previously constrained a minimum oxygen fugacity (fO2) needed to form pentlandite, (Fe,Ni)9S8, [6,7] and identified trends with pentlandite compositions between distinct meteorite groups [6,7]. We also identified a relationship between the at.% Fe/S ratio of pyrrhotite group sulfides and the fO2 of formation, either in the protoplanetary disk or the parent body during aqueous alteration or thermal alteration [13]. Since pentlandite formed with pyrrhotite (they are typically intergrown in these chondrite groups [1-14]), fO2 may have influenced pentlandite compositions. To increase the information gained from individual mineral systems, here we report the chemical compositions of pentlandite in chondrites that experienced a wide range of formation and parent body alteration conditions (including fO2 [13]). This will allow us to investigate a potential trend(s) with the pyrrhotite at.% Fe/S ratio, and by extension fO2. Samples and Analytical Procedures: We determined the major and minor element compositions of pentlandite in each of the following 54 chondrites: CI (Alais), a C1-ungrouped (Miller Range [MIL] 090292), C2-ungrouped (Tarda and Tagish Lake), CY (Belgica [B]-7904), CM1/2 (Allan Hills [ALH] 83100 and Kolang [two lithologies]), unheated CM2s (Aguas Zarcas [multiple lithologies], Mighei, Queen Alexandra Range [QUE] 97990, Theil Mountains [TIL] 91722, and D'Angelo Bluff [DNG] 06004), stage I heated CM2 (Asuka [A]-881458), stage II heated CM2 (Yamato [Y]-793321), CM-like (Sutter's Mill), CO3.00 (Dominion Range [DOM] 08006), CR1 (Grosvenor Mountains [GRO] 95577), CR-an (Al Rais), CR2 (Elephant Moraine [EET] 87770, EET 92048, EET 96259, Gao-Guenie (b), Graves Nunatak [GRA] 95229, LaPaz Ice Field [LAP] 02342, LAP 04720, MIL 090657, Northwest Africa [NWA] 801, Pecora Escarpment [PCA] 91082, QUE 99177, Shişr 033, and Y-793495), shock-heated CR2 (GRO 03116), CV3OxA (Allende), CV3OxB (Bali), and CV3Red (Vigarano), CK4 (ALH 85002 and Karoonda), CK5 (Larkman Nunatak [LAR] 06868), CK6 (Lewis Cliff [LEW] 87009), L3.05 (EET 90161 and QUE 97008), LL3 (Semarkona and Vicencia), LL4 (Hamlet and Soko-Banja), LL5 (Chelyabinsk and Siena), LL6 (Appley Bridge and Saint-Séverin), R3 (MET 01149), R3.6 (LAP 031275), R5 (LAP 03639), and R6 (LAP 04840 and MIL 11207) chondrites. We acquired high-resolution backscatter electron images and quantitative chemical compositions with the JEOL-8530F Hyperprobe electron microprobe analyzer (EPMA) at Arizona State University (ASU) and the Cameca SX-100 EPMA at the Uni-versity of Arizona (UA) following [13]. Some pentlandite compositions were previously reported [6,7,10,11]. Results and Discussion: Our data show that there is a relationship between the at.% Fe/S of pyrrhotite (data from [13]) and pentlandite compositions. Since the at.% Fe/S ratio of pyrrhotite is a proxy for fO2 [13], this demonstrates that there is a relationship between fO2 and pentlandite composition. Therefore, pentlandite compositions were influ-enced by the fO2 of formation. This is true whether pentlandite formed: (1) during chondrule formation in the protoplanetary disk (i.e., during chondrule cooling, as previously noted by [6,8,10,11] for CR2, CO3.00, and LL3.00 chondrites), (2) during thermal alteration on the parent asteroid under relatively reducing (i.e., LL4-6 chondrites) or oxidizing (i.e., R4-6 and CK chondrites) conditions, or (3) during oxidizing aqueous alteration (i.e., as in CI, CM1, C1-ung, and C2-ung chondrites). Therefore, in addition to the at.% Fe/S ratio of pyrrhotite, the chemical compositions of pentlandite can also be used as a proxy for the fO2 of formation. This discovery has implications for the interpreta-tion of pentlandite compositions in meteorites and in asteroid returned samples from Ryugu and Bennu. [ABSTRACT FROM AUTHOR]

Published
2022

49. Experimental Insights Into the Formation of Fullerenes and Carbon Nanotubes in Interstellar Space.

Author

Bernal, J. J., Zega, T. J., and Ziurys, L. M.

Subjects
*FULLERENES, *POLYCYCLIC aromatic hydrocarbons, *MULTIWALLED carbon nanotubes, *CARBON nanotubes, *TRANSMISSION electron microscopes, *SCANNING electron microscopes, *CIRCUMSTELLAR matter
Abstract

Introduction: The detection of the fullerenes C60 and C70 in space has transformed our understanding of chemical complexity in the interstellar medium (ISM) [1]. It also raises the question of the origins of these large, carbonbearing species, as well as the possibility of even larger molecules in astrophysical environments. While the presence of C60, C60 +, and C70 in the ISM is well established, there is significant controversy concerning the formation mechanism of this new class of molecules in environments that are hydrogen-rich. Several mechanisms have been previously proposed to explain fullerene formation, including photoprocessing of polycyclic aromatic hydrocarbon (PAH) molecules and destruction of hydrogenated amorphous carbon (HAC) grains [e.g. 2-3]. Our previous work [4] demonstrated that fullerenes such as C60 form from thermal decomposition of silicon carbide (SiC) grains. Here we report on the follow-up analysis of SiC thermal decomposition. This work is part of an effort to identify larger carbon nanostructures in the ISM. Sample and Method: A 3C-SiC powder (the same polytype as presolar grains [5]) with a particle size < 80 nm was obtained from US Research Nanomaterials to serve as an analog presolar grain sample. The SiC sample was deposited onto a Norcada microelectromechanical systems (MEMS) chip (model HTN-0101H), which was then inserted into a Hitachi "Blaze" sample holder [6]. A controller box powers the MEMS chip, which is operated through a Labview interface. Variable ramp rates, set points, and isothermal holds are achievable with the Blaze holder and MEMS platform. The SiC sample was heated in-situ to 1050 oC using the 200 keV Hitachi HF5000 scanning transmission electron microscope (S/TEM) located at the Lunar and Planetary Laboratory (LPL). The HF5000 is equipped with a cold field-emission gun, a 3rd-order spherical-aberration corrector for STEM mode, bright field and dark-field STEM detectors and an Oxford Instruments X-Max N 100 TLE EDS system with dual 100 mm2 windowless silicon-drift detectors (O = 2.0 sr). These heating experiments are designed to simulate shocks occurring in post-AGB stellar envelopes, where fullerenes are observed. Results and discussion: Our newest experimental findings reveal that heating the analog SiC grains yields a growth of hemispherical C60-sized nanostructures perpendicular to the SiC crystal surface - additional evidence for C60 formation, as we previously found. The carbon hemispheres are < 1nm in diameter, and are single-walled. These nanobud structures, upon a heating duration greater than a few minutes, transform into multi-walled carbon nanotubes (MWCNTs). The MWCNTs observed in the TEM experiment are composed of >4 graphene layers, with dimensions of ~4 nm in length. The MWCNTs also are capped, with each graphene layer of the tube curved at the end. These structures are larger than any of the currently-observed interstellar fullerene species, both in overall size and number of constituent carbon atoms. These experimental results suggest that such MWCNTs are likely to form in post-AGB shocks. As the post-AGB wind impacts the dust envelope surrounding the star, we hypothesize that the Si atoms leech from the SiC crystal, first forming reduced carbon layers in the form of graphene on the SiC grain surface. Due to the surface curvature and imperfections in the SiC grains, the graphene sheets then distort to form the C60-sized carbon nanobuds. The nanobuds may form C60, which leaves the grain surface, or act as growth sites to form larger MWCNTs. The structures, along with the smaller fullerenes, are subsequently injected into the ISM, where they have high radiation stability [7]. We will discuss the implications of these findings to presolar grain studies and the potential for these nanostructures as carriers of the Diffuse Interstellar Bands (DIBs). [ABSTRACT FROM AUTHOR]

Published
2022

50. IN-SITU FORMATION OF HALITE IN THE SIDI EL HABIB 001 ORDINARY CHONDRITE.

Author

Che, S. and Zega, T. J.

Subjects
*APATITE, *CARBONACEOUS chondrites (Meteorites), *CHROMITE, *SALT, *SCANNING electron microscopes, *ELECTRON probe microanalysis, *ROCK concerts, *METAL sulfides
Abstract

Introduction: All ordinary chondrites (OCs) experienced secondary alteration on their parent asteroids which has produced a diverse suite of secondary phases [e.g., 1]. However, because most OCs are finds, they experienced varied amounts of terrestrial weathering that could have altered their primary and secondary phases. The effects of terrestrial weathering can be minimized by studying fresh samples that were recovered soon after their fall. Sidi El Habib 001 (SEH 001) is an H5-anomalous ordinary chondrite that was discovered in December 2020 in Bordj Badji Mokhtar, Algeria (24.298°N, 3.745°E). It is a possible fall, i.e., it may correlate with the witnessed bright fireball in western Algeria on December 20, 2020 (Meteoritical Bulletin Database). The broken surface of the rock shows relatively abundant bright blue to purple grains of halite (up to 1 mm in size). Here we report preliminary results on SEH 001, with the aim of revealing potential textural relationships between halite and other phases. Sample and methods: A one-inch round polished-thick section of SEH 001 from the Buseck Center for Meteoirte Studies at Arizona State University was prepared and kindly loaned to us by Prof. Laurence Garvie. We acquired reflected light optical images using a Keyence VHX-7000 Series 4K digital microscope as initial sample documentation. Wavelength dispersive X-ray maps of the section were then acquired on a Cameca SX-100 electron microprobe to determine the overall sample petrography. More detailed information on sample microstructure was acquired with a Hitachi S-4800 scanning electron microscope equipped with energy-dispersive X-ray spectrometry (EDS). Results: The reflected light images reveal abundant (modal abundance: ~5.5%), randomly distributed, light blue anhedral halite grains. The largest grain measures ~2.5×1.5 mm, and most grains clearly visible in the optical images are a few hundred micrometers in size. Several halite-free clasts occur in the sample, as unveiled by the Na and Cl Xray maps. Most of these clasts have roughly rounded shapes, except for one clast with a nearly rectangular shape (~8×4 mm). These clasts do not show significant differences in texture and mineralogy from the halite-rich matrix and their boundaries are otherwise obscure, although the rectangular clast contains a slightly higher abundance of metal and sulfides (~13.7%, compared with ~7.3% of the matrix). Backscattered electron (BSE) images show that the halite grains predominantly occur adjacent to olivine, pyroxene, and feldspar, and many protrude into the interstitial regions. Minor fine-grained inclusions of silicates (mainly olivine, but also pyroxene and feldspar), sulfides, and chromite occur in halite. We also observe rare occurrences of sylvite partially replacing halite along grain boundaries. The largest halite grain contains widespread sylvite inclusions (<15 µm), some of which have cubic or elongate shapes. We observe a replacement texture of Cl-apatite by halite. Relict Cl-apatite grains occur in halite, and they have embayed or corroded interfaces (Fig. 1). Merrilite intergrows with Cl-apatite, but it does not replace halite. Halite is virtually absent in chondrules, but the albitic mesostases are compositionally heterogeneous and contain Cl enrichments on the periphery of chondrules based on EDS analyses. Implications: SEH 001 represents the third meteorite sample, apart from Monahans (1998) and Zag, that contains ubiquitous halides [2, 3]. Our study provides unambiguous textural evidence for the in-situ formation of halite on OC parent bodies. A sequential replacement relationship is revealed: merrillite-Cl-apatite-halite. We hypothesize that this alteration process contributed Cl to chondrule mesostases. The halite-free clasts are texturally equilibrated with the matrix, which might imply that halite formed during aqueous alteration prior to metamorphic equilibration. Halite can be thermally stable without metamorphic reactions with albite up to ~700 °C at low pressures [e.g., 4], and therefore could have survived metamorphism. Post-peak metamorphism disruption of OC parent bodies, as described in a rubble-pile model [e.g., 5], could also facilitate the preservation of halite. [ABSTRACT FROM AUTHOR]

Published
2022

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