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115 results on '"Tokar, R."'

2. Compositions of coarse and fine particles in martian soils at gale: A window into the production of soils

Author

Cousin, A., Meslin, P.Y., Wiens, R.C., Rapin, W., Mangold, N., Fabre, C., Gasnault, O., Forni, O., Tokar, R., Ollila, A., Schröder, S., Lasue, J., Maurice, S., Sautter, V., Newsom, H., Vaniman, D., Le Mouélic, S., Dyar, D., Berger, G., Blaney, D., Nachon, M., Dromart, G., Lanza, N., Clark, B., Clegg, S., Goetz, W., Berger, J., Barraclough, B., and Delapp, D.

Published
2015
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4. Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars

Author

Meslin, P.-Y., Gasnault, O., Forni, O., Schröder, S., Cousin, A., Berger, G., Clegg, S. M., Lasue, J., Maurice, S., Sautter, V., Le Mouélic, S., Wiens, R. C., Fabre, C., Goetz, W., Bish, D., Mangold, N., Ehlmann, B., Lanza, N., Harri, A.-M., Anderson, R., Rampe, E., McConnochie, T. H., Pinet, P., Blaney, D., Léveillé, R., Archer, D., Barraclough, B., Bender, S., Blake, D., Blank, J. G., Bridges, N., Clark, B. C., DeFlores, L., Delapp, D., Dromart, G., Dyar, M. D., Fisk, M., Gondet, B., Grotzinger, J., Herkenhoff, K., Johnson, J., Lacour, J.-L., Langevin, Y., Leshin, L., Lewin, E., Madsen, M. B., Melikechi, N., Mezzacappa, A., Mischna, M. A., Moores, J. E., Newsom, H., Ollila, A., Perez, R., Renno, N., Sirven, J.-B., Tokar, R., de la Torre, M., d'Uston, L., Vaniman, D., and Yingst, A.

Published
2013
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5. The dust halo of Saturn's largest icy moon, Rhea

Author

Jones, G.H., Roussos, E., Krupp, N., Beckmann, U., Coates, A.J., Crary, F., Dandouras, I., Dikarev, V., Dougherty, M.K., Garnier, P., Hansen, C.J., Hendrix, A.R., Hospodarsky, G.B., Johnson, R.E., Kempf, S., Khurana, K.K., Krimigis, S.M., Kruger, H., Kurth, W.S., Lagg, A., McAndrews, H.J., Mitchell, D.G., Paranicas, C., Postberg, F., Russell, C.T., Saur, J., Seiss, M., Spahn, F., Srama, R., Strobel, D.F., Tokar, R., Wahlund, J.-E., Wilson, R.J., Woch, J., and Young, D.

Subjects
Satellites -- Observations, Saturn (Planet) -- Magnetic properties
Published
2008

6. Distribution of hydrogen in the near surface of Mars: evidence for subsurface ice deposits. (Reports)

Author

Boynton, W.V., Feldman, W.C., Squyres, S.W., Prettyman, T.H., Bruckner, J., Evans, L.G., Reedy, R.C., Starr, R., Arnold, J.R., Drake, D.M., Englert, P.A.J., Metzger, A.E., Mitrofanov, Igor, Trombka, J.I., d'Uston, C., Wanke, H., Gasnault, O., Hamara, D.K., Janes, D.M., Marcialis, R.L., Maurice, S., Mikheeva, I., Taylor, G.J., Tokar, R., and Shinohara, C.

Subjects
Planets -- Discovery and exploration, Water, Underground -- Discovery and exploration, Mars (Planet) -- Discovery and exploration, Science and technology, Discovery and exploration
Abstract

Using the Gamma-Ray Spectrometer on the Mars Odyssey, we have identified two regions near the poles that are enriched in hydrogen. The data indicate the presence of a subsurface layer enriched in hydrogen overlain by a hydrogenpoor layer. The thickness of the upper layer decreases with decreasing distance to the pole, ranging from a column density of about 150 grams per square centimeter at -42° latitude to about 40 grams per square centimeter at -77°. The hydrogen-rich regions correlate with regions of predicted ice stability. We suggest that the host of the hydrogen in the subsurface layer is ice, which constitutes 35 ± 15% of the layer by weight., There is ample evidence that water has been important in shaping the martian surface (1, 2) and that water is present on Mars today in the north polar residual cap [...]

Published
2002

8. Modification of the Plasma in the Near-Vicinity of Enceladus by the Enveloping Dust

Author

Farrell, W. M, Kurth, W. S, Tokar, R. L, Wahlund, J-E, Gurnett, D. A, Wang, Z, MacDowall, R. J, Morooka, M. W, Johnson, R. E, and Waite, J. H., Jr

Subjects
Geophysics
Abstract

The plasma near Saturn's equator is quasi-corotating, but those fluid elements entering the near-vicinity of the moon Enceladus become uniquely modified. Besides the solid body, the Moon has a surrounding dust envelop that we show herein to be detected approx.20 Enceladus radii (1 R(sub E) = 252 km) both north and south of the body. Previous reports indicate that co rotating plasma slows down substantially in the near-vicinity of En eel ad us. We show herein that the commencement of this plasma slow down matches closely with Cassini's entry into the dense portions of the enveloping dust in the northern hemisphere above the Moon. We also examine in detail the source of the dust about 400 km above the south polar fissures. We find that a large positive potential must exist between the south pole of the moon and the spacecraft to account for ions streaming away from the pole on connecting magnetic field lines

Published
2010
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9. Saturn's Magnetosphere and Properties of Upstream Flow at Titan: Preliminary Results

Author

Sittler, E. C., Jr, Hartle, R. E, Cooper, J. F, Lipatov, A, Bertucci, C, Coates, A. J, Arridge, C, Szego, K, Shappirio, M, Simipson, D. G, Tokar, R, and Young, D. T

Subjects
Astrophysics
Abstract

Using Cassini Plasma Spectrometer (CAPS) Ion Mass Spectrometer (IMS) measurements, we present the ion fluid properties and its ion composition of the upstream flow for Titan's interaction with Saturn's magnetosphere. A 3D ion moments algorithm is used which is essentially model independent with only requirement is that ion flow is within the CAPS IMS 2(pi) steradian field-of-view (FOV) and that the ion 'velocity distribution function (VDF) be gyrotropic. These results cover the period from TA flyby (2004 day 300) to T22 flyby (2006 363). Cassini's in situ measurements of Saturn's magnetic field show it is stretched out into a magnetodisc configuration for Saturn Local Times (SLT) centered about midnight local time. Under those circumstances the field is confined near the equatorial plane with Titan either above or below the magnetosphere current sheet. Similar to Jupiter's outer magnetosphere where a magnetodisc configuration applies, one expects the heavy ions within Saturn's outer magnetosphere to be confined within a few degrees of the current sheet while at higher magnetic latitudes protons should dominate. We show that when Cassini is between dusk-midnight-dawn local time and spacecraft is not within the current sheet that light ions (H, 142) tend to dominate the ion composition for the upstream flow. If true, one may expect the interaction between Saturn's magnetosphere, locally devoid of heavy ions and Titan's upper atmosphere and exosphere to be significantly different from that for Voyager 1, TA and TB when heavy ions were present in the upstream flow. We also present observational evidence for Saturn's magnetosphere interaction with Titan's extended H and H2 corona which can extend approx. 1 Rs from Titan.

Published
2009

11. Cassini Observations of Saturn's Magnetotail Region: Preliminary Results

Author

Sittler, E. C, Arridge, C, Rymer, A, Coates, A, Krupp, N, Blanc, M, Richardson, J, Andre, N, Thomsen, M, Tokar, R. L, McAndrews, H. J, Henderson, Mike, Cooper, J. F, Burger, M, Simpson, D, Khurana, K. K, Russell, C, Dougherty, M, and Young, D. T

Subjects
Lunar And Planetary Science And Exploration
Abstract

Using Cassini thermal plasma, hot plasma and magnetic field observations for several intervals between the dawn meridian of Saturn's outer magnetosphere and Saturn's magnetotail region, we investigate the structure of the magnetotail, plasma and magnetic field properties within tail-like current sheet regions and ion flows within the magnetotail regions. We use Cassini Plasma Spectrometer (CAPS) Ion Mass Spectrometer (IMS), Electron Plasma Spectrometer (ELS) observations, MIMI LEMMS ion and electron observations and Cassini magnetometer data (MAG) to characterize the plasma environment. IMS observations are used to measure plasma flow velocities from which one can infer rotation versus convective flows. IMS composition measurements are used to trace the source of plasma from the inner magnetosphere (protons, H2+ and water group ions) versus an external solar wind source (protons and ~ e +i+on s). A critical parameter for both models is the strength of the convection electric field with respect to the rotational electric field for the large scale magnetosphere. For example, are there significant return flows (i.e., negative radial velocities, VR < 0) and/or plasmoids (V(sub R) > 0) within the magnetotail region? Initial preliminary evidence of such out flows and return flows was presented by Sittler et al. This talk complements the more global analysis by McAndrews et al.

Published
2007

12. Composition and Dynamics of Plasma in Saturn's Magnetosphere

Author

Young, D. T., Berthelier, J.-J., Blanc, M., Burch, J. L., Bolton, S., Coates, A. J., Crary, F. J., Goldstein, R., Grande, M., Hill, T. W., Johnson, R. E., Baragiola, R. A., Kelha, V., McComas, D. J., Mursula, K., Sittler, E. C., Svenes, K. R., Szegö, K., Tanskanen, P., Thomsen, M. F., Bakshi, S., Barraclough, B. L., Bebesi, Z., Delapp, D., Dunlop, M. W., Gosling, J. T., Furman, J. D., Gilbert, L. K., Glenn, D., Holmlund, C., Illiano, J.-M., Lewis, G. R., Linder, D. R., Maurice, S., McAndrews, H. J., Narheim, B. T., Pallier, E., Reisenfeld, D., Rymer, A. M., Smith, H. T., Tokar, R. L., Vilppola, J., and Zinsmeyer, C.

Published
2005

13. THE PLASMA ION AND ELECTRON INSTRUMENTS FOR THE GENESIS MISSION

Author

Barraclough, B. L., Dors, E. E., Abeyta, R. A., Alexander, J. F., Ameduri, F. P., Baldonado, J. R., Bame, S. J., Casey, P. J., Dirks, G., Everett, D. T., Gosling, J. T., Grace, K. M., Guerrero, D. R., Kolar, J. D., Kroesche, J. L., Jr, Lockhart, W. L., Mccomas, D. J., Mietz, D. E., Roese, J., Sanders, J., Steinberg, J. T., Tokar, R. L., Urdiales, C., and Wiens, R. C.

Published
2003

16. An Unusual Coronal Mass Ejection: First Solar Wind Electron, Proton, Alpha Monitor (SWEPAM) Results from the Advanced Composition Explorer

Author

McComas, D. J, Bame, S. J, Barker, P. L, Delapp, D. M, Gosling, J. T, Skoug, R. M, Tokar, R. L, Riley, P, Feldman, W. C, and Santiago, E

Subjects
Solar Physics
Abstract

This paper reports the first scientific results from the Solar Wind Electron Proton Alpha Monitor (SWEPAM) instrument on board the Advanced Composition Explorer (ACE) spacecraft. We analyzed a coronal mass ejection (CME) observed in the solar wind using data from early February, 1998. This event displayed several of the common signatures of CMEs, such as counterstreaming halo electrons and depressed ion and electron temperatures, as well as some unusual features. During a portion of the CME traversal, SWEPAM measured a very large helium to proton abundance ratio. Other heavy ions, with a set of ionization states consistent with normal (1 to 2x10(exp 6) K) coronal temperatures, were proportionately enhanced at this time. These observations suggest a source for at least some of the CME material, where heavy ions are initially concentrated relative to hydrogen and then accelerated up into the solar wind, independent of their mass and first ionization potential.

Published
2001

17. A Prolonged He(+) Enhancement within a Coronal Mass Ejection in the Solar Wind

Author

Skoug, R. M, Bame, S. J, Feldman, W. C, Gosling, J. T, McComas, D. J, Steinberg, J. T, Tokar, R. L, Riley, P, Burlaga, L. F, and Ness, N. F

Subjects
Solar Physics
Abstract

A coronal mass ejection and magnetic cloud containing an unusually large enhancement of He+ was observed in the solar wind by the plasma and magnetic field instruments on the Advanced Composition Explorer (ACE) spacecraft on May 2-4, 1998. The He+/He++ ratio during this event exceeded 0.5% for a period of more than 24 hours, and reached values as high as 100%. The high He+/He++ ratio indicates the presence of prominence material, and in fact a disappearing filament and prominence were observed at the Sun in association with this event. The prolonged observation of He+ indicates that prominence material extended through mu ch of this CME, the first such observation in a CME in the solar wind.

Published
2001

18. Multi-Spacecraft Observations of Interplanetary Shocks

Author

Smith, C. W, Tokar, R. L, Skoug, R. M, and Szabo, A

Subjects
Astrophysics
Abstract

Using multi-spacecraft observations primarily from ACE and WIND and from IMP 8 and Geotail when available, the 3-dimensional structure of interplanetary shocks on the hundred Earth radii scale will be discussed. The complete magnetic field, and solar wind ion and electron data sets were used to fit the shocks with a full non-linear least squares fitting "Rankine-Hugoniot" technique yielding the local shock surface normals and speeds with associated uncertainties. Multi-spacecraft results reveal that on the distance scale of ACE's L1 halo orbit the shocks deviate from a simple planar geometry. This result has important consequences for the prediction of the exact arrival times of interplanetary shocks at the Earth's magnetosphere, and hence, on the reliability of space weather predictions. It also has implications on the coherence scale of solar wind structures and their evolution from the Sun to Earth.

Published
1999

19. Multi-Spacecraft Observations of Interplanetary Shocks

Author

Szabo, A, Smith, C. W, Tokar, R. L, and Skoug, R. M

Subjects
Astrophysics
Abstract

Using multi-spacecraft observations primarily from ACE and WIND, and from IMP 8 and Geotail when available, the 3-dimensional structure of interplanetary shocks on the hundred Earth radii scale will be discussed. The complete magnetic field, and solar wind ion and electron data sets were used to fit the shocks with a full non-linear least squares fit "Rankine-Hugoniot" technique yielding the local shock surface normals and speeds with associated uncertainties. Multi-spacecraft results reveal that on the distance scale of ACE's L1 halo orbit the shocks deviate significantly from a simple planar geometry. This result has important consequences for the prediction of the exact arrival times of interplanetary shocks at the Earth's magnetosphere, and hence, on the reliability of space weather predictions. It also has implications on the coherence scale of solar wind structures and their evolution from the Sun to Earth.

Published
1999

20. ChemCam activities and discoveries during the nominal mission of the Mars Science Laboratory in Gale crater, Mars

Author

Thompson, L., Williams, A., Williams, R., Blaney, D., Calef, F., Dietrich, W., Edgett, K., Fisk, M., Gellert, R., Grotzinger, J., Kah, L., McLennan, S., Palucis, M., Siebach, K., Stack, K., Sumner, D., Yingst, A., Maurice, S., Clegg, S., Wiens, R., Gasnault, O., Rapin, W., Forni, O., Cousin, A., Sautter, V., Mangold, N., Le Deit, L., Nachon, M., Anderson, R., Lanza, N., Fabre, C., Payré, V., Lasue, J., Meslin, P.-Y., Léveillé, R., Barraclough, B., Beck, P., Bender, S., Berger, G., Bridges, J., Bridges, N., Dromart, G., Dyar, M., Francis, R., Frydenvang, J., Gondet, B., Ehlmann, B., Herkenhoff, K., Johnson, J., Langevin, Y., Madsen, M., Melikechi, N., Lacour, J.-L., Le Mouélic, Stéphane, Lewin, E., Newsom, H., Ollila, A., Pinet, P., Schröder, S., Sirven, J.-B., Tokar, R., Toplis, M., D'Uston, C., Vaniman, D., Vasavada, A., Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Oregon State University (OSU), Department of Physics [Guelph], University of Guelph, California Institute of Technology (CALTECH), Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley], University of California-University of California, Division of Geological and Planetary Sciences [Pasadena], University of California [Davis] (UC Davis), University of California, Planetary Science Institute [Tucson] (PSI), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Los Alamos National Laboratory (LANL), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), DLR Institute of Planetary Research, German Aerospace Center (DLR), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Canadian Space Agency (CSA), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Centre National de la Recherche Scientifique (CNRS), Space Research Centre [Leicester], University of Leicester, 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), Astrogeology Science Center [Flagstaff], United States Geological Survey [Reston] (USGS), Centre for Infection and Immunity, Optical Science Center for Applied Research (OSCAR), Delaware State University (DSU), Service d'études analytiques et de réactivité des surfaces (SEARS), Département de Physico-Chimie (DPC), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), Institute of Meteoritics [Albuquerque] (IOM), The University of New Mexico [Albuquerque], Technologies et systèmes d'information pour les agrosystèmes (UR TSCF), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Commissariat à l'Energie Atomique et aux Energies Alternatives, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Dynamique terrestre et planétaire (DTP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Centre d'étude spatiale des rayonnements (CESR), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), NASA-California Institute of Technology (CALTECH), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), University of California (UC), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-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])-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 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]), 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), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), 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]), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3)

Subjects
010504 meteorology & atmospheric sciences, atomic Emission spectroscopy, Mars, Mineralogy, Context (language use), 01 natural sciences, Analytical Chemistry, Atmosphere, laser-spectroscopy, Spectroscopy, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, LIBS, Chemistry, 010401 analytical chemistry, Noachian, Gale crater, Crust, Mars Exploration Program, 15. Life on land, Gale Crater, 0104 chemical sciences, Characterization (materials science), Geochemistry, in-situ, ChemCam, 13. Climate action, [SDU]Sciences of the Universe [physics]
Abstract

At Gale crater, Mars, ChemCam acquired its first laser-induced breakdown spectroscopy (LIBS) target on Sol 13 of the landed portion of the mission (a Sol is a Mars day). Up to Sol 800, more than 188 000 LIBS spectra were acquired on more than 5800 points distributed over about 650 individual targets. We present a comprehensive review of ChemCam scientific accomplishments during that period, together with a focus on the lessons learned from the first use of LIBS in space. For data processing, we describe new tools that had to be developed to account for the uniqueness of Mars data. With regard to chemistry, we present a summary of the composition range measured on Mars for major-element oxides (SiO_2, TiO_2, Al_2O_3, FeO_T, MgO, CaO, Na_2O, K_2O) based on various multivariate models, with associated precisions. ChemCam also observed H, and the non-metallic elements C, O, P, and S, which are usually difficult to quantify with LIBS. F and Cl are observed through their molecular lines. We discuss the most relevant LIBS lines for detection of minor and trace elements (Li, Rb, Sr, Ba, Cr, Mn, Ni, and Zn). These results were obtained thanks to comprehensive ground reference datasets, which are set to mimic the expected mineralogy and chemistry on Mars. With regard to the first use of LIBS in space, we analyze and quantify, often for the first time, each of the advantages of using stand-off LIBS in space: no sample preparation, analysis within its petrological context, dust removal, sub-millimeter scale investigation, multi-point analysis, the ability to carry out statistical surveys and whole-rock analyses, and rapid data acquisition. We conclude with a discussion of ChemCam performance to survey the geochemistry of Mars, and its valuable support of decisions about selecting where and whether to make observations with more time and resource-intensive tools in the rover's instrument suite. In the end, we present a bird's-eye view of the many scientific results: discovery of felsic Noachian crust, first observation of hydrated soil, discovery of manganese-rich coatings and fracture fills indicating strong oxidation potential in Mars' early atmosphere, characterization of soils by grain size, and wide scale mapping of sedimentary strata, conglomerates, and diagenetic materials.

Published
2016

22. Martian fluvial conglomerates at gale crater

Author

Williams, R. M. E., Grotzinger, J. P., Dietrich, W. E., Gupta, S., Sumner, D. Y., Wiens, R. C., Mangold, N., Malin, M. C., Edgett, K. S., Maurice, S., Forni, O., Gasnault, O., Ollila, A., Newsom, H. E., Dromart, G., Palucis, M. C., Yingst, R. A., Anderson, R. B., Herkenhoff, K. E., Le Mouelic, S., Goetz, W., Madsen, M. B., Koefoed, A., Jensen, J. K., Bridges, J. C., Schwenzer, S. P., Lewis, K. W., Stack, K. M., Rubin, D., Kah, L. C., Bell, J. F., Farmer, J. D., Sullivan, R., Van Beek, T., Blaney, D. L., Pariser, O., Deen, R. G., Kemppinen, O., Bridges, N., Johnson, J. R., Minitti, M., Cremers, D., Edgar, L., Godber, A., Wadhwa, M., Wellington, D., McEwan, I., Newman, C., Richardson, M., Charpentier, A., Peret, L., King, P., Blank, J., Weigle, G., Schmidt, M., Li, S., Milliken, R., Robertson, K., Sun, V., Baker, M., Edwards, C., Ehlmann, B., Farley, K., Griffes, J., Miller, H., Newcombe, M., Pilorget, C., Rice, M., Siebach, K., Stolper, E., Brunet, C., Hipkin, V., Leveille, R., Marchand, G., Sobron Sanchez, P., Favot, L., Cody, G., Steele, A., Fluckiger, L., Lees, D., Nefian, A., Martin, M., Gailhanou, M., Westall, F., Israel, G., Agard, C., Baroukh, J., Donny, C., Gaboriaud, A., Guillemot, P., Lafaille, V., Lorigny, E., Paillet, A., Perez, R., Saccoccio, M., Yana, C., Aparicio, C. A., Caride Rodriguez, J., Carrasco Blazquez, I., Gomez Gomez, F., Elvira, J. G., Hettrich, S., Lepinette Malvitte, A., Marin Jimenez, M., Frias, J. M., Soler, J. M., Torres, F. J. M., Molina Jurado, A., Sotomayor, L. M., Munoz Caro, G., Navarro Lopez, S., Gonzalez, V. P., Garcia, J. P., Rodriguez Manfredi, J. A., Planello, J. J. R., Alejandra Sans Fuentes, S., Sebastian Martinez, E., Torres Redondo, J., O'Callaghan, R. U., Zorzano Mier, M.-P., Chipera, S., Lacour, J.-L., Mauchien, P., Sirven, J.-B., Manning, H., Fairen, A., Hayes, A., Joseph, J., Squyres, S., Thomas, P., Dupont, A., Lundberg, A., Melikechi, N., Mezzacappa, A., DeMarines, J., Grinspoon, D., Reitz, G., Prats, B., Atlaskin, E., Genzer, M., Harri, A.-M., Haukka, H., Kahanpaa, H., Kauhanen, J., Paton, M., Polkko, J., Schmidt, W., Siili, T., Fabre, C., Wray, J., Wilhelm, M. B., Poitrasson, F., Patel, K., Gorevan, S., Indyk, S., Paulsen, G., Bish, D., Schieber, J., Gondet, B., Langevin, Y., Geffroy, C., Baratoux, D., Berger, G., Cros, A., Uston, C. d., Lasue, J., Lee, Q.-M., Meslin, P.-Y., Pallier, E., Parot, Y., Pinet, P., Schroder, S., Toplis, M., Lewin, E., Brunner, W., Heydari, E., Achilles, C., Oehler, D., Sutter, B., Cabane, M., Coscia, D., Szopa, C., Robert, F., Sautter, V., Nachon, M., Buch, A., Stalport, F., Coll, P., Francois, P., Raulin, F., Teinturier, S., Cameron, J., Clegg, S., Cousin, A., DeLapp, D., Dingler, R., Jackson, R. S., Johnstone, S., Lanza, N., Little, C., Nelson, T., Williams, R. B., Jones, A., Kirkland, L., Treiman, A., Baker, B., Cantor, B., Caplinger, M., Davis, S., Duston, B., Fay, D., Hardgrove, C., Harker, D., Herrera, P., Jensen, E., Kennedy, M. R., Krezoski, G., Krysak, D., Lipkaman, L., McCartney, E., McNair, S., Nixon, B., Posiolova, L., Ravine, M., Salamon, A., Saper, L., Stoiber, K., Supulver, K., Van Beek, J., Zimdar, R., French, K. L., Iagnemma, K., Miller, K., Summons, R., Goesmann, F., Hviid, S., Johnson, M., Lefavor, M., Lyness, E., Breves, E., Dyar, M. D., Fassett, C., Blake, D. F., Bristow, T., DesMarais, D., Edwards, L., Haberle, R., Hoehler, T., Hollingsworth, J., Kahre, M., Keely, L., McKay, C., Bleacher, L., Brinckerhoff, W., Choi, D., Conrad, P., Dworkin, J. P., Eigenbrode, J., Floyd, M., Freissinet, C., Garvin, J., Glavin, D., Harpold, D., Mahaffy, P., Martin, D. K., McAdam, A., Pavlov, A., Raaen, E., Smith, M. D., Stern, J., Tan, F., Trainer, M., Meyer, M., Posner, A., Voytek, M., Anderson, R. C., Aubrey, A., Beegle, L. W., Behar, A., Brinza, D., Calef, F., Christensen, L., Crisp, J. A., DeFlores, L., Feldman, J., Feldman, S., Flesch, G., Hurowitz, J., Jun, I., Keymeulen, D., Maki, J., Mischna, M., Morookian, J. M., Parker, T., Pavri, B., Schoppers, M., Sengstacken, A., Simmonds, J. J., Spanovich, N., de la Torre Juarez, M., Vasavada, A. R., Webster, C. R., Yen, A., Archer, P. D., Cucinotta, F., Jones, J. H., Ming, D., Morris, R. V., Niles, P., Rampe, E., Nolan, T., Fisk, M., Radziemski, L., Barraclough, B., Bender, S., Berman, D., Dobrea, E. N., Tokar, R., Vaniman, D., Leshin, L., Cleghorn, T., Huntress, W., Manhes, G., Hudgins, J., Olson, T., Stewart, N., Sarrazin, P., Grant, J., Vicenzi, E., Wilson, S. A., Bullock, M., Ehresmann, B., Hamilton, V., Hassler, D., Peterson, J., Rafkin, S., Zeitlin, C., Fedosov, F., Golovin, D., Karpushkina, N., Kozyrev, A., Litvak, M., Malakhov, A., Mitrofanov, I., Mokrousov, M., Nikiforov, S., Prokhorov, V., Sanin, A., Tretyakov, V., Varenikov, A., Vostrukhin, A., Kuzmin, R., Clark, B., Wolff, M., McLennan, S., Botta, O., Drake, D., Bean, K., Lemmon, M., Lee, E. M., Sucharski, R., Hernandez, M. A. d. P., Blanco Avalos, J. J., Ramos, M., Kim, M.-H., Malespin, C., Plante, I., Muller, J.-P., Gonzalez, R. N., Ewing, R., Boynton, W., Downs, R., Fitzgibbon, M., Harshman, K., Morrison, S., Kortmann, O., Williams, A., Lugmair, G., Wilson, M. A., Jakosky, B., Zunic, T. B., Frydenvang, J., Kinch, K., Stipp, S. L. S., Boyd, N., Campbell, J. L., Gellert, R., Perrett, G., Pradler, I., VanBommel, S., Jacob, S., Owen, T., Rowland, S., Savijarvi, H., Boehm, E., Bottcher, S., Burmeister, S., Guo, J., Kohler, J., Garcia, C. M., Mellin, R. M., Schweingruber, R. W., McConnochie, T., Benna, M., Franz, H., Bower, H., Brunner, A., Blau, H., Boucher, T., Carmosino, M., Atreya, S., Elliott, H., Halleaux, D., Renno, N., Wong, M., Pepin, R., Elliott, B., Spray, J., Thompson, L., Gordon, S., Williams, J., Vasconcelos, P., Bentz, J., Nealson, K., Popa, R., Moersch, J., Tate, C., Day, M., Kocurek, G., Hallet, B., Sletten, R., Francis, R., McCullough, E., Cloutis, E., ten Kate, I. L., Arvidson, R., Fraeman, A., Scholes, D., Slavney, S., Stein, T., Ward, J., Berger, J., Moores, J. E., NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, Petrology, GeoRessources, and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
MSL Mars Gale Crater Fluvial Activity, Martian, Multidisciplinary, 010504 meteorology & atmospheric sciences, Outcrop, Curiosity rover, Geochemistry, Mars, Sediment, Fluvial, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mars Exploration Program, 01 natural sciences, Abrasion (geology), martian fluvial conglomerates, 13. Climate action, Rocknest, 0103 physical sciences, MSL, Sedimentary rock, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract

Going to Mars The Mars Science Laboratory spacecraft containing the Curiosity rover, was launched from Earth in November 2011 and arrived at Gale crater on Mars in August 2012. Zeitlin et al. (p. 1080 ) report measurements of the energetic particle radiation environment inside the spacecraft during its cruise to Mars, confirming the hazard likely to be posed by this radiation to astronauts on a future potential trip to Mars. Williams et al. (p. 1068 , see the Perspective by Jerolmack ) report the detection of sedimentary conglomerates (pebbles mixed with sand and turned to rock) at Gale crater. The rounding of the rocks suggests abrasion of the pebbles as they were transported by flowing water several kilometers or more from their source.

Published
2013

23. Curiosity at Gale Crater, Mars: Characterization and analysis of the rocknest sand shadow

Author

Blake, D. F., Morris, R. V., Kocurek, G., Morrison, S. M., Downs, R. T., Bish, D., Ming, D. W., Edgett, K. S., Rubin, D., Goetz, W., Madsen, M. B., Sullivan, R., Gellert, R., Campbell, I., Treiman, A. H., McLennan, S. M., Yen, A. S., Grotzinger, J., Vaniman, D. T., Chipera, S. J., Achilles, C. N., Rampe, E. B., Sumner, D., Meslin, P.- Y., Maurice, S., Forni, O., Gasnault, O., Fisk, M., Schmidt, M., Mahaffy, P., Leshin, L. A., Glavin, D., Steele, A., Freissinet, C., Navarro-Gonzalez, R., Yingst, R. A., Kah, L. C., Bridges, N., Lewis, K. W., Bristow, T. F., Farmer, J. D., Crisp, J. A., Stolper, E. M., Des Marais, D. J., Sarrazin, P., Agard, C., Alves Verdasca, J. A., Anderson, R., Archer, D., Armiens-Aparicio, C., Arvidson, R., Atlaskin, E., Atreya, S., Aubrey, A., Baker, B., Baker, M., Balic-Zunic, T., Baratoux, D., Baroukh, J., Barraclough, B., Bean, K., Beegle, L., Behar, A., Bell, J., Bender, S., Benna, M., Bentz, J., Berger, G., Berger, J., Berman, D., Blanco Avalos, J. J., Blaney, D., Blank, J., Blau, H., Bleacher, L., Boehm, E., Botta, O., Bottcher, S., Boucher, T., Bower, H., Boyd, N., Boynton, B., Breves, E., Bridges, J., Brinckerhoff, W., Brinza, D., Brunet, C., Brunner, A., Brunner, W., Buch, A., Bullock, M., Burmeister, S., Cabane, M., Calef, F., Cameron, J., Cantor, B., Caplinger, M., Rodriguez, J. C., Carmosino, M., Blazquez, I. C., Charpentier, A., Choi, D., Clark, B., Clegg, S., Cleghorn, T., Cloutis, E., Cody, G., Coll, P., Conrad, P., Coscia, D., Cousin, A., Cremers, D., Cros, A., Cucinotta, F., d'Uston, C., Davis, S., Day, M., Juarez, M. d. l. T., DeFlores, L., DeLapp, D., DeMarines, J., Dietrich, W., Dingler, R., Donny, C., Drake, D., Dromart, G., Dupont, A., Duston, B., Dworkin, J., Dyar, M. D., Edgar, L., Edwards, C., Edwards, L., Ehlmann, B., Ehresmann, B., Eigenbrode, J., Elliott, B., Elliott, H., Ewing, R., Fabre, C., Fairen, A., Farley, K., Fassett, C., Favot, L., Fay, D., Fedosov, F., Feldman, J., Feldman, S., Fitzgibbon, M., Flesch, G., Floyd, M., Fluckiger, L., Fraeman, A., Francis, R., Francois, P., Franz, H., French, K. L., Frydenvang, J., Gaboriaud, A., Gailhanou, M., Garvin, J., Geffroy, C., Genzer, M., Godber, A., Goesmann, F., Golovin, D., Gomez, F. G., Gomez-Elvira, J., Gondet, B., Gordon, S., Gorevan, S., Grant, J., Griffes, J., Grinspoon, D., Guillemot, P., Guo, J., Gupta, S., Guzewich, S., Haberle, R., Halleaux, D., Hallet, B., Hamilton, V., Hardgrove, C., Harker, D., Harpold, D., Harri, A.-M., Harshman, K., Hassler, D., Haukka, H., Hayes, A., Herkenhoff, K., Herrera, P., Hettrich, S., Heydari, E., Hipkin, V., Hoehler, T., Hollingsworth, J., Hudgins, J., Huntress, W., Hurowitz, J., Hviid, S., Iagnemma, K., Indyk, S., Israel, G., Jackson, R., Jacob, S., Jakosky, B., Jensen, E., Jensen, J. K., Johnson, J., Johnson, M., Johnstone, S., Jones, A., Jones, J., Joseph, J., Jun, I., Kahanpaa, H., Kahre, M., Karpushkina, N., Kasprzak, W., Kauhanen, J., Keely, L., Kemppinen, O., Keymeulen, D., Kim, M.-H., Kinch, K., King, P., Kirkland, L., Koefoed, A., Kohler, J., Kortmann, O., Kozyrev, A., Krezoski, J., Krysak, D., Kuzmin, R., Lacour, J. L., Lafaille, V., Langevin, Y., Lanza, N., Lasue, J., Le Mouelic, S., Lee, E. M., Lee, Q.-M., Lees, D., Lefavor, M., Lemmon, M., Lepinette Malvitte, A., Leveille, R., Lewin-Carpintier, E., Li, S., Lipkaman, L., Little, C., Litvak, M., Lorigny, E., Lugmair, G., Lundberg, A., Lyness, E., Maki, J., Malakhov, A., Malespin, C., Malin, M., Mangold, N., Manning, H., Marchand, G., Marin Jimenez, M., Martin Garcia, C., Martin, D., Martin, M., Martinez-Frias, J., Martin-Soler, J., Martin-Torres, F. J., Mauchien, P., McAdam, A., McCartney, E., McConnochie, T., McCullough, E., McEwan, I., McKay, C., McNair, S., Melikechi, N., Meyer, M., Mezzacappa, A., Miller, H., Miller, K., Milliken, R., Minitti, M., Mischna, M., Mitrofanov, I., Moersch, J., Mokrousov, M., Molina Jurado, A., Moores, J., Mora-Sotomayor, L., Morookian, J. M., Mueller-Mellin, R., Muller, J.-P., Munoz Caro, G., Nachon, M., Navarro Lopez, S., Nealson, K., Nefian, A., Nelson, T., Newcombe, M., Newman, C., Newsom, H., Nikiforov, S., Niles, P., Nixon, B., Dobrea, E. N., Nolan, T., Oehler, D., Ollila, A., Olson, T., Owen, T., Pablo, H., Paillet, A., Pallier, E., Palucis, M., Parker, T., Parot, Y., Patel, K., Paton, M., Paulsen, G., Pavlov, A., Pavri, B., Peinado-Gonzalez, V., Pepin, R., Peret, L., Perez, R., Perrett, G., Peterson, J., Pilorget, C., Pinet, P., Pla-Garcia, J., Plante, I., Poitrasson, F., Polkko, J., Popa, R., Posiolova, L., Pradler, I., Prats, B., Prokhorov, V., Purdy, S. W., Raaen, E., Radziemski, L., Rafkin, S., Ramos, M., Raulin, F., Ravine, M., Reitz, G., Renno, N., Rice, M., Richardson, M., Robert, F., Rodriguez Manfredi, J. A., Romeral-Planello, J. J., Rowland, S., Saccoccio, M., Salamon, A., Sandoval, J., Sanin, A., Sans Fuentes, S. A., Saper, L., Sautter, V., Savijarvi, H., Schieber, J., Schmidt, W., Scholes, D., Schoppers, M., Schroder, S., Sebastian Martinez, E., Sengstacken, A., Shterts, R., Siebach, K., Siili, T., Simmonds, J., Sirven, J.-B., Slavney, S., Sletten, R., Smith, M., Sobron Sanchez, P., Spanovich, N., Spray, J., Squyres, S., Stack, K., Stalport, F., Stein, T., Stern, J., Stewart, N., Stipp, S. L. S., Stoiber, K., Sucharski, B., Summons, R., Sun, V., Supulver, K., Sutter, B., Szopa, C., Tate, C., Teinturier, S., ten Kate, I. L., Thomas, P., Thompson, L., Tokar, R., Toplis, M., Torres Redondo, J., Trainer, M., Tretyakov, V., Urqui-O'Callaghan, R., Van Beek, J., Van Beek, T., VanBommel, S., Varenikov, A., Vasavada, A., Vasconcelos, P., Vicenzi, E., Vostrukhin, A., Voytek, M., Wadhwa, M., Ward, J., Webster, C., Weigle, E., Wellington, D., Westall, F., Wiens, R. C., Wilhelm, M. B., Williams, A., Williams, J., Williams, R., Williams, R. B., Wilson, M., Wimmer-Schweingruber, R., Wolff, M., Wong, M., Wray, J., Wu, M., Yana, C., Zeitlin, C., Zimdar, R., Zorzano Mier, M.-P., GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), NASA Ames Research Center (ARC), NASA Johnson Space Center (JSC), NASA, Department of Geological Sciences [Austin], Jackson School of Geosciences (JSG), University of Texas at Austin [Austin]-University of Texas at Austin [Austin], Department of Geology [Tucson], University of Arizona, Department of Geological Sciences [Bloomington], Indiana University [Bloomington], Indiana University System-Indiana University System, Malin Space Science Systems (MSSS), NASA Goddard Space Flight Center (GSFC), NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, and Petrology

Subjects
Basalt, Meridiani Planum, Multidisciplinary, 010504 meteorology & atmospheric sciences, Curiosity rover, Geochemistry, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mars Exploration Program, Exploration of Mars, 01 natural sciences, Astrobiology, Impact crater, 13. Climate action, MSL Mars Gale Crater Rocknest, Rocknest, 0103 physical sciences, Sample Analysis at Mars, Aeolian processes, MSL, Rocknest aeolian deposit, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract

The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand

Published
2013

24. The Petrochemistry of Jake_M: A Martian Mugearite

Author

Stolper, E. M., Baker, M. B., Newcombe, M. E., Schmidt, M. E., Treiman, A. H., Cousin, A., Dyar, M. D., Fisk, M. R., Gellert, R., King, P. L., Leshin, L., Maurice, S., McLennan, S. M., Minitti, M. E., Perrett, G., Rowland, S., Sautter, V., Wiens, R. C., Kemppinen, O., Bridges, N., Johnson, J. R., Cremers, D., Bell, J. F., Edgar, L., Farmer, J., Godber, A., Wadhwa, M., Wellington, D., McEwan, I., Newman, C., Richardson, M., Charpentier, A., Peret, L., Blank, J., Weigle, G., Li, S., Milliken, R., Robertson, K., Sun, V., Edwards, C., Ehlmann, B., Farley, K., Griffes, J., Grotzinger, J., Miller, H., Pilorget, C., Rice, M., Siebach, K., Stack, K., Brunet, C., Hipkin, V., Leveille, R., Marchand, G., Sanchez, P. S., Favot, L., Cody, G., Steele, A., Fluckiger, L., Lees, D., Nefian, A., Martin, M., Gailhanou, M., Westall, F., Israel, G., Agard, C., Baroukh, J., Donny, C., Gaboriaud, A., Guillemot, P., Lafaille, V., Lorigny, E., Paillet, A., Perez, R., Saccoccio, M., Yana, C., Armiens-Aparicio, C., Rodriguez, J. C., Blazquez, I. C., Gomez, F. G., Gomez-Elvira, J., Hettrich, S., Malvitte, A. L., Jimenez, M. M., Martinez-Frias, J., Martin-Soler, J., Martin-Torres, F. J., Jurado, A. M., Mora-Sotomayor, L., Caro, G. M., Lopez, S. N., Peinado-Gonzalez, V., Pla-Garcia, J., Manfredi, J. A. R., Romeral-Planello, J. J., Fuentes, S. A. S., Martinez, E. S., Redondo, J. T., Urqui-O'Callaghan, R., Mier, M.-P. Z., Chipera, S., Lacour, J.-L., Mauchien, P., Sirven, J.-B., Manning, H., Fairen, A., Hayes, A., Joseph, J., Squyres, S., Sullivan, R., Thomas, P., Dupont, A., Lundberg, A., Melikechi, N., Mezzacappa, A., DeMarines, J., Grinspoon, D., Reitz, G., Prats, B., Atlaskin, E., Genzer, M., Harri, A.-M., Haukka, H., Kahanpaa, H., Kauhanen, J., Paton, M., Polkko, J., Schmidt, W., Siili, T., Fabre, C., Wray, J., Wilhelm, M. B., Poitrasson, F., Patel, K., Gorevan, S., Indyk, S., Paulsen, G., Gupta, S., Bish, D., Schieber, J., Gondet, B., Langevin, Y., Geffroy, C., Baratoux, D., Berger, G., Cros, A., d'Uston, C., Forni, O., Gasnault, O., Lasue, J., Lee, Q.-M., Meslin, P.-Y., Pallier, E., Parot, Y., Pinet, P., Schroder, S., Toplis, M., Lewin, E., Brunner, W., Heydari, E., Achilles, C., Oehler, D., Sutter, B., Cabane, M., Coscia, D., Szopa, C., Teinturier, S., Dromart, G., Robert, F., Le Mouelic, S., Mangold, N., Nachon, M., Buch, A., Stalport, F., Coll, P., Francois, P., Raulin, F., Cameron, J., Clegg, S., DeLapp, D., Dingler, R., Jackson, R. S., Johnstone, S., Lanza, N., Little, C., Nelson, T., Williams, R. B., Kirkland, L., Baker, B., Cantor, B., Caplinger, M., Davis, S., Duston, B., Edgett, K., Fay, D., Hardgrove, C., Harker, D., Herrera, P., Jensen, E., Kennedy, M. R., Krezoski, G., Krysak, D., Lipkaman, L., Malin, M., McCartney, E., McNair, S., Nixon, B., Posiolova, L., Ravine, M., Salamon, A., Saper, L., Stoiber, K., Supulver, K., Van Beek, J., Van Beek, T., Zimdar, R., French, K. L., Iagnemma, K., Miller, K., Summons, R., Goesmann, F., Goetz, W., Hviid, S., Johnson, M., Lefavor, M., Lyness, E., Breves, E., Fassett, C., Blake, D. F., Bristow, T., DesMarais, D., Edwards, L., Haberle, R., Hoehler, T., Hollingsworth, J., Kahre, M., Keely, L., McKay, C., Bleacher, L., Brinckerhoff, W., Choi, D., Conrad, P., Dworkin, J. P., Eigenbrode, J., Floyd, M., Freissinet, C., Garvin, J., Glavin, D., Harpold, D., Mahaffy, P., Martin, D. K., McAdam, A., Pavlov, A., Raaen, E., Smith, M. D., Stern, J., Tan, F., Trainer, M., Meyer, M., Posner, A., Voytek, M., Anderson, R. C., Aubrey, A., Beegle, L. W., Behar, A., Blaney, D., Brinza, D., Calef, F., Christensen, L., Crisp, J., DeFlores, L., Feldman, J., Feldman, S., Flesch, G., Hurowitz, J., Jun, I., Keymeulen, D., Maki, J., Mischna, M., Morookian, J. M., Parker, T., Pavri, B., Schoppers, M., Sengstacken, A., Simmonds, J. J., Spanovich, N., Juarez, M. d. l. T., Vasavada, A., Webster, C. R., Yen, A., Archer, P. D., Cucinotta, F., Jones, J. H., Ming, D., Morris, R. V., Niles, P., Rampe, E., Nolan, T., Radziemski, L., Barraclough, B., Bender, S., Berman, D., Dobrea, E. N., Tokar, R., Vaniman, D., Williams, R. M. E., Yingst, A., Lewis, K., Cleghorn, T., Huntress, W., Manhes, G., Hudgins, J., Olson, T., Stewart, N., Sarrazin, P., Grant, J., Vicenzi, E., Wilson, S. A., Bullock, M., Ehresmann, B., Hamilton, V., Hassler, D., Peterson, J., Rafkin, S., Zeitlin, C., Fedosov, F., Golovin, D., Karpushkina, N., Kozyrev, A., Litvak, M., Malakhov, A., Mitrofanov, I., Mokrousov, M., Nikiforov, S., Prokhorov, V., Sanin, A., Tretyakov, V., Varenikov, A., Vostrukhin, A., Kuzmin, R., Clark, B., Wolff, M., Botta, O., Drake, D., Bean, K., Lemmon, M., Schwenzer, S. P., Anderson, R. B., Herkenhoff, K., Lee, E. M., Sucharski, R., Hernandez, M. A. d. P., Avalos, J. J. B., Ramos, M., Jones, A., Kim, M.-H., Malespin, C., Plante, I., Muller, J.-P., Navarro-Gonzalez, R., Ewing, R., Boynton, W., Downs, R., Fitzgibbon, M., Harshman, K., Morrison, S., Dietrich, W., Kortmann, O., Palucis, M., Sumner, D. Y., Williams, A., Lugmair, G., Wilson, M. A., Rubin, D., Jakosky, B., Balic-Zunic, T., Frydenvang, J., Jensen, J. K., Kinch, K., Koefoed, A., Madsen, M. B., Stipp, S. L. S., Boyd, N., Campbell, J. L., Pradler, I., VanBommel, S., Jacob, S., Owen, T., Savijarvi, H., Boehm, E., Bottcher, S., Burmeister, S., Guo, J., Kohler, J., Garcia, C. M., Mueller-Mellin, R., Wimmer-Schweingruber, R., Bridges, J. C., McConnochie, T., Benna, M., Franz, H., Bower, H., Brunner, A., Blau, H., Boucher, T., Carmosino, M., Atreya, S., Elliott, H., Halleaux, D., Renno, N., Wong, M., Pepin, R., Elliott, B., Spray, J., Thompson, L., Gordon, S., Newsom, H., Ollila, A., Williams, J., Vasconcelos, P., Bentz, J., Nealson, K., Popa, R., Kah, L. C., Moersch, J., Tate, C., Day, M., Kocurek, G., Hallet, B., Sletten, R., Francis, R., McCullough, E., Cloutis, E., ten Kate, I. L., Arvidson, R., Fraeman, A., Scholes, D., Slavney, S., Stein, T., Ward, J., Berger, J., Moores, J. E., GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), California Institute of Technology (CALTECH), Department of Earth Sciences [St. Catharines], Brock University [Canada], Lunar and Planetary Institute [Houston] (LPI), Los Alamos National Laboratory (LANL), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Mount Holyoke College, Oregon State University (OSU), University of Guelph, Research School of Earth Sciences [Canberra] (RSES), Australian National University (ANU), Rensselaer Polytechnic Institute (RPI), State University of New York (SUNY), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), University of Hawaii, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), MSL Science Team, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Curiosity rover, Geochemistry, Mars, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, Jake_M: a martian mugearite, chemistry.chemical_compound, Nepheline, MSL, Chemical composition, 0105 earth and related environmental sciences, Martian, Phonolite, Multidisciplinary, Fractional crystallization (geology), petrochemistry, Igneous rock, Planetary science, MSL Mars Petrochemistry, chemistry, 13. Climate action, Petrochemistry, Geology, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; "Jake_M," the first rock analyzed by the Alpha Particle X-ray Spectrometer instrument on the Curiosity rover, differs substantially in chemical composition from other known martian igneous rocks: It is alkaline (>15% normative nepheline) and relatively fractionated. Jake_M is compositionally similar to terrestrial mugearites, a rock type typically found at ocean islands and continental rifts. By analogy with these comparable terrestrial rocks, Jake_M could have been produced by extensive fractional crystallization of a primary alkaline or transitional magma at elevated pressure, with or without elevated water contents. The discovery of Jake_M suggests that alkaline magmas may be more abundant on Mars than on Earth and that Curiosity could encounter even more fractionated alkaline rocks (for example, phonolites and trachytes).

Published
2013

25. Volatile, Isotope, and Organic Analysis of Martian Fines with the Mars Curiosity Rover

Author

Leshin, L. A., Mahaffy, P. R., Webster, C. R., Cabane, M., Coll, P., Conrad, P. G., Archer, P. D., Atreya, S. K., Brunner, A. E., Buch, A., Eigenbrode, J. L., Flesch, G. J., Franz, H. B., Freissinet, C., Glavin, D. P., McAdam, A. C., Miller, K. E., Ming, D. W., Morris, R. V., Navarro-Gonzalez, R., Niles, P. B., Owen, T., Pepin, R. O., Squyres, S., Steele, A., Stern, J. C., Summons, R. E., Sumner, D. Y., Sutter, B., Szopa, C., Teinturier, S., Trainer, M. G., Wray, J. J., Grotzinger, J. P., Kemppinen, O., Bridges, N., Johnson, J. R., Minitti, M., Cremers, D., Bell, J. F., Edgar, L., Farmer, J., Godber, A., Wadhwa, M., Wellington, D., McEwan, I., Newman, C., Richardson, M., Charpentier, A., Peret, L., King, P., Blank, J., Weigle, G., Schmidt, M., Li, S., Milliken, R., Robertson, K., Sun, V., Baker, M., Edwards, C., Ehlmann, B., Farley, K., Griffes, J., Miller, H., Newcombe, M., Pilorget, C., Rice, M., Siebach, K., Stack, K., Stolper, E., Brunet, C., Hipkin, V., Leveille, R., Marchand, G., Sanchez, P. S., Favot, L., Cody, G., Fluckiger, L., Lees, D., Nefian, A., Martin, M., Gailhanou, M., Westall, F., Israel, G., Agard, C., Baroukh, J., Donny, C., Gaboriaud, A., Guillemot, P., Lafaille, V., Lorigny, E., Paillet, A., Perez, R., Saccoccio, M., Yana, C., Armiens-Aparicio, C., Rodriguez, J. C., Blazquez, I. C., Gomez, F. G., Gomez-Elvira, J., Hettrich, S., Malvitte, A. L., Jimenez, M. M., Martinez-Frias, J., Martin-Soler, J., Martin-Torres, F. J., Jurado, A. M., Mora-Sotomayor, L., Caro, G. M., Lopez, S. N., Peinado-Gonzalez, V., Pla-Garcia, J., Manfredi, J. A. R., Romeral-Planello, J. J., Fuentes, S. A. S., Martinez, E. S., Redondo, J. T., Urqui-O'Callaghan, R., Mier, M.-P. Z., Chipera, S., Lacour, J.-L., Mauchien, P., Sirven, J.-B., Manning, H., Fairen, A., Hayes, A., Joseph, J., Sullivan, R., Thomas, P., Dupont, A., Lundberg, A., Melikechi, N., Mezzacappa, A., DeMarines, J., Grinspoon, D., Reitz, G., Prats, B., Atlaskin, E., Genzer, M., Harri, A.-M., Haukka, H., Kahanpaa, H., Kauhanen, J., Paton, M., Polkko, J., Schmidt, W., Siili, T., Fabre, C., Wilhelm, M. B., Poitrasson, F., Patel, K., Gorevan, S., Indyk, S., Paulsen, G., Gupta, S., Bish, D., Schieber, J., Gondet, B., Langevin, Y., Geffroy, C., Baratoux, D., Berger, G., Cros, A., d'Uston, C., Forni, O., Gasnault, O., Lasue, J., Lee, Q.-M., Maurice, S., Meslin, P.-Y., Pallier, E., Parot, Y., Pinet, P., Schroder, S., Toplis, M., Lewin, E., Brunner, W., Heydari, E., Achilles, C., Oehler, D., Coscia, D., Dromart, G., Robert, F., Sautter, V., Le Mouelic, S., Mangold, N., Nachon, M., Stalport, F., Francois, P., Raulin, F., Cameron, J., Clegg, S., Cousin, A., DeLapp, D., Dingler, R., Jackson, R. S., Johnstone, S., Lanza, N., Little, C., Nelson, T., Wiens, R. C., Williams, R. B., Jones, A., Kirkland, L., Treiman, A., Baker, B., Cantor, B., Caplinger, M., Davis, S., Duston, B., Edgett, K., Fay, D., Hardgrove, C., Harker, D., Herrera, P., Jensen, E., Kennedy, M. R., Krezoski, G., Krysak, D., Lipkaman, L., Malin, M., McCartney, E., McNair, S., Nixon, B., Posiolova, L., Ravine, M., Salamon, A., Saper, L., Stoiber, K., Supulver, K., Van Beek, J., Van Beek, T., Zimdar, R., French, K. L., Iagnemma, K., Goesmann, F., Goetz, W., Hviid, S., Johnson, M., Lefavor, M., Lyness, E., Breves, E., Dyar, M. D., Fassett, C., Blake, D. F., Bristow, T., DesMarais, D., Edwards, L., Haberle, R., Hoehler, T., Hollingsworth, J., Kahre, M., Keely, L., McKay, C., Bleacher, L., Brinckerhoff, W., Choi, D., Dworkin, J. P., Floyd, M., Garvin, J., Harpold, D., Martin, D. K., Pavlov, A., Raaen, E., Smith, M. D., Tan, F., Meyer, M., Posner, A., Voytek, M., Anderson, R. C., Aubrey, A., Beegle, L. W., Behar, A., Blaney, D., Brinza, D., Calef, F., Christensen, L., Crisp, J. A., DeFlores, L., Feldman, J., Feldman, S., Hurowitz, J., Jun, I., Keymeulen, D., Maki, J., Mischna, M., Morookian, J. M., Parker, T., Pavri, B., Schoppers, M., Sengstacken, A., Simmonds, J. J., Spanovich, N., Juarez, M. d. l. T., Vasavada, A. R., Yen, A., Cucinotta, F., Jones, J. H., Rampe, E., Nolan, T., Fisk, M., Radziemski, L., Barraclough, B., Bender, S., Berman, D., Dobrea, E. N., Tokar, R., Vaniman, D., Williams, R. M. E., Yingst, A., Lewis, K., Cleghorn, T., Huntress, W., Manhes, G., Hudgins, J., Olson, T., Stewart, N., Sarrazin, P., Grant, J., Vicenzi, E., Wilson, S. A., Bullock, M., Ehresmann, B., Hamilton, V., Hassler, D., Peterson, J., Rafkin, S., Zeitlin, C., Fedosov, F., Golovin, D., Karpushkina, N., Kozyrev, A., Litvak, M., Malakhov, A., Mitrofanov, I., Mokrousov, M., Nikiforov, S., Prokhorov, V., Sanin, A., Tretyakov, V., Varenikov, A., Vostrukhin, A., Kuzmin, R., Clark, B., Wolff, M., McLennan, S., Botta, O., Drake, D., Bean, K., Lemmon, M., Schwenzer, S. P., Anderson, R. B., Herkenhoff, K., Lee, E. M., Sucharski, R., Hernandez, M. A. d. P., Avalos, J. J. B., Ramos, M., Kim, M.-H., Malespin, C., Plante, I., Muller, J.-P., Ewing, R., Boynton, W., Downs, R., Fitzgibbon, M., Harshman, K., Morrison, S., Dietrich, W., Kortmann, O., Palucis, M., Williams, A., Lugmair, G., Wilson, M. A., Rubin, D., Jakosky, B., Balic-Zunic, T., Frydenvang, J., Jensen, J. K., Kinch, K., Koefoed, A., Madsen, M. B., Stipp, S. L. S., Boyd, N., Campbell, J. L., Gellert, R., Perrett, G., Pradler, I., VanBommel, S., Jacob, S., Rowland, S., Savijarvi, H., Boehm, E., Bottcher, S., Burmeister, S., Guo, J., Kohler, J., Garcia, C. M., Mueller-Mellin, R., Wimmer-Schweingruber, R., Bridges, J. C., McConnochie, T., Benna, M., Bower, H., Blau, H., Boucher, T., Carmosino, M., Elliott, H., Halleaux, D., Renno, N., Wong, M., Elliott, B., Spray, J., Thompson, L., Gordon, S., Newsom, H., Ollila, A., Williams, J., Vasconcelos, P., Bentz, J., Nealson, K., Popa, R., Kah, L. C., Moersch, J., Tate, C., Day, M., Kocurek, G., Hallet, B., Sletten, R., Francis, R., McCullough, E., Cloutis, E., ten Kate, I. L., Arvidson, R., Fraeman, A., Scholes, D., Slavney, S., Stein, T., Ward, J., Berger, J., Moores, J. E., Department of Earth and Environmental Sciences [Troy, NY], Rensselaer Polytechnic Institute (RPI), NASA Goddard Space Flight Center (GSFC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Astromaterials Research and Exploration Science (ARES), NASA Johnson Space Center (JSC), NASA-NASA, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, Center for Research and Exploration in Space Science and Technology [GSFC] (CRESST), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Laboratorio de Química de Plasmas y Estudios Planetarios [Mexico], Instituto de Ciencias Nucleares [Mexico], Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM)-Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Cornell University [New York], Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science, University of California [Davis] (UC Davis), University of California (UC), Jacobs Technology ESCG, Institut Pierre-Simon-Laplace (IPSL), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Earth and Atmospheric Sciences [Atlanta], Georgia Institute of Technology [Atlanta], Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, Petrology, California Institute of Technology (CALTECH)-NASA, Universidad Nacional Autónoma de México (UNAM)-Universidad Nacional Autónoma de México (UNAM), Carnegie Institution for Science [Washington], University of California, École normale supérieure - Paris (ENS Paris), IMPEC - LATMOS, Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Minnesota [Twin Cities], Cornell University, and École normale supérieure - Paris (ENS Paris)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National d'Études Spatiales [Toulouse] (CNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)

Subjects
Martian, Multidisciplinary, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Thermal decomposition, Curiosity rover, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry.chemical_element, Mars, organic analysis, Mars Exploration Program, 01 natural sciences, Astrobiology, chemistry.chemical_compound, chemistry, 13. Climate action, Isotopes of carbon, Rocknest, 0103 physical sciences, Sample Analysis at Mars, Carbonate, MSL Mars Volatiles Isotopes Organics Soil Gale Crater, 010303 astronomy & astrophysics, Carbon, 0105 earth and related environmental sciences
Abstract

Samples from the Rocknest aeolian deposit were heated to ~835°C under helium flow and evolved gases analyzed by Curiosity’s Sample Analysis at Mars instrument suite. H 2 O, SO 2 , CO 2 , and O 2 were the major gases released. Water abundance (1.5 to 3 weight percent) and release temperature suggest that H 2 O is bound within an amorphous component of the sample. Decomposition of fine-grained Fe or Mg carbonate is the likely source of much of the evolved CO 2 . Evolved O 2 is coincident with the release of Cl, suggesting that oxygen is produced from thermal decomposition of an oxychloride compound. Elevated δD values are consistent with recent atmospheric exchange. Carbon isotopes indicate multiple carbon sources in the fines. Several simple organic compounds were detected, but they are not definitively martian in origin.

Published
2013

26. X-ray diffraction results from mars science laboratory: Mineralogy of rocknest at Gale crater

Author

Bish, D. L., Blake, D. F., Vaniman, D. T., Chipera, S. J., Morris, R. V., Ming, D. W., Treiman, A. H., Sarrazin, P., Morrison, S. M., Downs, R. T., Achilles, C. N., Yen, A. S., Bristow, T. F., Crisp, J. A., Morookian, J. M., Farmer, J. D., Rampe, E. B., Stolper, E. M., Spanovich, N., Achilles, C., Agard, C., Verdasca, J. A. A., Anderson, R., Archer, D., Armiens-Aparicio, C., Arvidson, R., Atlaskin, E., Atreya, S., Aubrey, A., Baker, B., Baker, M., Balic-Zunic, T., Baratoux, D., Baroukh, J., Barraclough, B., Bean, K., Beegle, L., Behar, A., Bell, J., Bender, S., Benna, M., Bentz, J., Berger, G., Berger, J., Berman, D., Bish, D., Avalos, J. J. B., Blaney, D., Blank, J., Blau, H., Bleacher, L., Boehm, E., Botta, O., Bottcher, S., Boucher, T., Bower, H., Boyd, N., Boynton, B., Breves, E., Bridges, J., Bridges, N., Brinckerhoff, W., Brinza, D., Bristow, T., Brunet, C., Brunner, A., Brunner, W., Buch, A., Bullock, M., Burmeister, S., Cabane, M., Calef, F., Cameron, J., Campbell, J. I., Cantor, B., Caplinger, M., Rodriguez, J. C., Carmosino, M., Blazquez, I. C., Charpentier, A., Chipera, S., Choi, D., Clark, B., Clegg, S., Cleghorn, T., Cloutis, E., Cody, G., Coll, P., Conrad, P., Coscia, D., Cousin, A., Cremers, D., Crisp, J., Cros, A., Cucinotta, F., d'Uston, C., Davis, S., Day, M. K., Juarez, M. d. l. T., DeFlores, L., DeLapp, D., DeMarines, J., DesMarais, D., Dietrich, W., Dingler, R., Donny, C., Downs, B., Drake, D., Dromart, G., Dupont, A., Duston, B., Dworkin, J., Dyar, M. D., Edgar, L., Edgett, K., Edwards, C., Edwards, L., Ehlmann, B., Ehresmann, B., Eigenbrode, J., Elliott, B., Elliott, H., Ewing, R., Fabre, C., Fairen, A., Farley, K., Farmer, J., Fassett, C., Favot, L., Fay, D., Fedosov, F., Feldman, J., Feldman, S., Fisk, M., Fitzgibbon, M., Flesch, G., Floyd, M., Fluckiger, L., Forni, O., Fraeman, A., Francis, R., Francois, P., Franz, H., Freissinet, C., French, K. L., Frydenvang, J., Gaboriaud, A., Gailhanou, M., Garvin, J., Gasnault, O., Geffroy, C., Gellert, R., Genzer, M., Glavin, D., Godber, A., Goesmann, F., Goetz, W., Golovin, D., Gomez, F. G., Gomez-Elvira, J., Gondet, B., Gordon, S., Gorevan, S., Grant, J., Griffes, J., Grinspoon, D., Grotzinger, J., Guillemot, P., Guo, J., Gupta, S., Guzewich, S., Haberle, R., Halleaux, D., Hallet, B., Hamilton, V., Hardgrove, C., Harker, D., Harpold, D., Harri, A.-M., Harshman, K., Hassler, D., Haukka, H., Hayes, A., Herkenhoff, K., Herrera, P., Hettrich, S., Heydari, E., Hipkin, V., Hoehler, T., Hollingsworth, J., Hudgins, J., Huntress, W., Hurowitz, J., Hviid, S., Iagnemma, K., Indyk, S., Israel, G., Jackson, R., Jacob, S., Jakosky, B., Jensen, E., Jensen, J. K., Johnson, J., Johnson, M., Johnstone, S., Jones, A., Jones, J., Joseph, J., Jun, I., Kah, L., Kahanpaa, H., Kahre, M., Karpushkina, N., Kasprzak, W., Kauhanen, J., Keely, L., Kemppinen, O., Keymeulen, D., Kim, M.-H., Kinch, K., King, P., Kirkland, L., Kocurek, G., Koefoed, A., Kohler, J., Kortmann, O., Kozyrev, A., Krezoski, J., Krysak, D., Kuzmin, R., Lacour, J. L., Lafaille, V., Langevin, Y., Lanza, N., Lasue, J., Le Mouelic, S., Lee, E. M., Lee, Q.-M., Lees, D., Lefavor, M., Lemmon, M., Malvitte, A. L., Leshin, L., Leveille, R., Lewin-Carpintier, E., Lewis, K., Li, S., Lipkaman, L., Little, C., Litvak, M., Lorigny, E., Lugmair, G., Lundberg, A., Lyness, E., Madsen, M., Mahaffy, P., Maki, J., Malakhov, A., Malespin, C., Malin, M., Mangold, N., Manhes, G., Manning, H., Marchand, G., Jimenez, M. M., Garcia, C. M., Martin, D., Martin, M., Martinez-Frias, J., Martin-Soler, J., Martin-Torres, F. J., Mauchien, P., Maurice, S., McAdam, A., McCartney, E., McConnochie, T., McCullough, E., McEwan, I., McKay, C., McLennan, S., McNair, S., Melikechi, N., Meslin, P.-Y., Meyer, M., Mezzacappa, A., Miller, H., Miller, K., Milliken, R., Ming, D., Minitti, M., Mischna, M., Mitrofanov, I., Moersch, J., Mokrousov, M., Jurado, A. M., Moores, J., Mora-Sotomayor, L., Morris, R., Morrison, S., Mueller-Mellin, R., Muller, J.-P., Caro, G. M., Nachon, M., Lopez, S. N., Navarro-Gonzalez, R., Nealson, K., Nefian, A., Nelson, T., Newcombe, M., Newman, C., Newsom, H., Nikiforov, S., Niles, P., Nixon, B., Dobrea, E. N., Nolan, T., Oehler, D., Ollila, A., Olson, T., Owen, T., Hernandez, M. A. d. P., Paillet, A., Pallier, E., Palucis, M., Parker, T., Parot, Y., Patel, K., Paton, M., Paulsen, G., Pavlov, A., Pavri, B., Peinado-Gonzalez, V., Pepin, R., Peret, L., Perez, R., Perrett, G., Peterson, J., Pilorget, C., Pinet, P., Pla-Garcia, J., Plante, I., Poitrasson, F., Polkko, J., Popa, R., Posiolova, L., Posner, A., Pradler, I., Prats, B., Prokhorov, V., Purdy, S. W., Raaen, E., Radziemski, L., Rafkin, S., Ramos, M., Rampe, E., Raulin, F., Ravine, M., Reitz, G., Renno, N., Rice, M., Richardson, M., Robert, F., Robertson, K., Manfredi, J. A. R., Romeral-Planello, J. J., Rowland, S., Rubin, D., Saccoccio, M., Salamon, A., Sandoval, J., Sanin, A., Fuentes, S. A. S., Saper, L., Sautter, V., Savijarvi, H., Schieber, J., Schmidt, M., Schmidt, W., Scholes, D. D., Schoppers, M., Schroder, S., Schwenzer, S., Martinez, E. S., Sengstacken, A., Shterts, R., Siebach, K., Siili, T., Simmonds, J., Sirven, J.-B., Slavney, S., Sletten, R., Smith, M., Sanchez, P. S., Spray, J., Squyres, S., Stack, K., Stalport, F., Steele, A., Stein, T., Stern, J., Stewart, N., Stipp, S. L. S., Stoiber, K., Stolper, E., Sucharski, B., Sullivan, R., Summons, R., Sumner, D., Sun, V., Supulver, K., Sutter, B., Szopa, C., Tan, F., Tate, C., Teinturier, S., ten Kate, I., Thomas, P., Thompson, L., Tokar, R., Toplis, M., Redondo, J. T., Trainer, M., Treiman, A., Tretyakov, V., Urqui-O'Callaghan, R., Van Beek, J., Van Beek, T., VanBommel, S., Vaniman, D., Varenikov, A., Vasavada, A., Vasconcelos, P., Vicenzi, E., Vostrukhin, A., Voytek, M., Wadhwa, M., Ward, J., Webster, C., Weigle, E., Wellington, D., Westall, F., Wiens, R. C., Wilhelm, M. B., Williams, A., Williams, J., Williams, R., Williams, R. B. M., Wilson, M., Wimmer-Schweingruber, R., Wolff, M., Wong, M., Wray, J., Wu, M., Yana, C., Yen, A., Yingst, A., Zeitlin, C., Zimdar, R., Mier, M.-P. Z., GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), NWO-NSO: The role of perchlorates in the preservation of organic compounds on Mars, and Petrology

Subjects
Multidisciplinary, 010504 meteorology & atmospheric sciences, Water on Mars, Curiosity rover, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mineralogy, Mars, Mars Exploration Program, Martian soil, engineering.material, 01 natural sciences, MSL Mars X-ray Diffraction Mineralogy Rocknest Gale Crater, Meteorite, Impact crater, 13. Climate action, Rocknest, 0103 physical sciences, Pigeonite, engineering, Composition of Mars, MSL, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, mineralogy of Rocknest at Gale crater
Abstract

The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian bedform in Gale crater. Analysis of the soil with the Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, and pigeonite, with minor K-feldspar, magnetite, quartz, anhydrite, hematite, and ilmenite. The minor phases are present at, or near, detection limits. The soil also contains 27 ± 14 weight percent x-ray amorphous material, likely containing multiple Fe 3+ - and volatile-bearing phases, including possibly a substance resembling hisingerite. The crystalline component is similar to the normative mineralogy of certain basaltic rocks from Gusev crater on Mars and of martian basaltic meteorites. The amorphous component is similar to that found on Earth in places such as soils on the Mauna Kea volcano, Hawaii.

Published
2013

29. A diffusive equilibrium model for the plasma density in Saturn's magnetosphere

Author

Persoon, A. M., Gurnett, Donald A., Santolýk, Ondrej, Kurth, William S., Faden, J. B., Groene, J. B., Lewis, G. R., Coates, A. J., Wilson, R. J., Tokar, R. L., Wahlund, Jan-Erik, Moncuquet, Michel, Department of Physics and Astronomy, Iowa State University, Faculty of Mathematics and Physics, Charles University, University College of London [London] (UCL), Space and Atmospheric Science Group, Los Alamos National Laboratory, Los Alamos, Swedish Institute of Space Physics, 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), Physique des plasmas, and 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Electron density measurements have been obtained by the Cassini Radio and Plasma Wave Science (RPWS) instrument for more than 50 passes through Saturn's inner magnetosphere from 30 June 2004 to 30 September 2007. The electron densities are derived from RPWS measurements of the upper hybrid resonance frequency and span latitudes up to 35° and L values from 3.6 to 10. The electron density measurements are combined with ion anisotropy measurements from the Cassini Plasma Spectrometer (CAPS) and electron temperature measurements from the RPWS and CAPS to develop a diffusive equilibrium model for the distribution of water group ions, hydrogen ions, and electrons in the inner region of Saturn's magnetosphere. The model uses an analytical solution of the field-aligned force equation, including the ambipolar electric field, to determine the equatorial ion densities and scale heights as a function of L. Density contour plots for water group ions, hydrogen ions, and electrons are presented.

Published
2009

30. Topographic control of hydrogen deposits at low to mid latitudes of Mars

Author

Feldman, W. C., Prettyman, T. H., Maurice, S., Nelli, S., Elphic, R., Funsten, H. O., Gasnault, O., Lawrence, D. J., Murphy, J. R., Tokar, R. L., Vaniman, D. T., Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]
Published
2005

31. Structure of a slow mode shock observed in the plasma sheet boundary layer

Author

Feldman, W. C, Tokar, R. L, Birn, J, Hones, E. W., Jr, and Bame, S. J

Subjects
Geophysics
Abstract

A detailed study of the plasma parameters and magnetic field measured using instrumentation aboard ISEE 2 during the recovery phase of a substorm on Apr. 24, 1979, is presented. The purpose of this study was to determine the nature and structure of the lobe-plasma sheet boundary layer. The analysis shows that the lobeward edge of the boundary is consistent with a freestanding slow mode shock. This shock is followed by a slow compression wave containing a trailing ion cyclotron wave which also stands in the flow. Measurement of the cross-tail current in the shock and the current system within the wave gives a shock thickness and wavelength comparable to but larger than both the upstream ion inertial length and the downstream proton gyroradius. Equality of the shock thickness with the standing ion cyclotron wavelength suggests that the steepness of the front is limited by dispersion rather than current-driven anomalous resistivity.

Published
1987

32. Nonadiabatic electron heating at high-Mach-number perpendicular shocks

Author

Tokar, R. L, Aldrich, C. H, Forslund, D. W, and Quest, K. B

Subjects
Plasma Physics
Abstract

Fully kinetic simulations of high-Mach-number (HMN) perpendicular collisionless shocks are described. It is shown that electron acceleration in the cross-shock electron field can produce downstream electron temperature significantly higher than those expected for adiabatic compression. The momentum space for test electrons at Mach 6 is illustrated.

Published
1986
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33. Simulation of the electron acoustic instability in the polar cusp

Author

Lin, C. S, Winske, D, and Tokar, R. L

Subjects
Geophysics
Abstract

A computer simulation of the beam-driven electron acoustic instability in the polar cusp is used to investigate the temporal evolution of typical cusp electron distribution functions in self-consistently generated wave fields. The simulation results are compared with linear, second-order, and nonlinear theory. The behavior of the instability over a range of plasma parameters, such as beam speed and the cold electron density, is shown. The saturation mechanism of the instability is examined, and the relevance of the results for observations of cusp hiss are discussed.

Published
1985

34. The whistler mode in a Vlasov plasma

Author

Tokar, R. L and Gary, S. P

Subjects
Plasma Physics
Abstract

In this study, properties of small-amplitude parallel and oblique whistler-mode waves are investigated for a wide range of plasma parameters by numerically solving the full electromagnetic Vlasov-dispersion equation. To investigate the cold-plasma and electrostatic approximations for the whistler mode, the results are compared with results obtained using these descriptions. For large wavelengths, the cold-plasma description is often accurate, while for short wavelengths and sufficiently oblique propagation, the electrostatic description is often accurate. The study demonstrates that in a Vlasov plasma the whistler mode near resonance has a group velocity more nearly parallel to the magnetic field than that predicted by cold-plasma theory.

Published
1985
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35. The second-order theory of electromagnetic hot ion beam instabilities

Author

Gary, S. P and Tokar, R. L

Subjects
Space Radiation
Abstract

The present investigation is concerned with the application of a second-order theory for electromagnetic instabilities in a collisionless plasma to two modes which resonate with hot ion beams. The application of the theory is strictly limited to the linear growth phase. However, the application of the theory may be extended to obtain a description of the beam at postsaturation if the wave-beam resonance is sufficiently broad in velocity space. Under the considered limitations, it is shown that, as in the cold beam case, the fluctuating fields do not gain appreciable momentum and that the primary exchange of momentum is between the beam and main component.

Published
1985

36. The propagation and growth of whistler mode waves generated by electron beams in earth's bow shock

Author

Tokar, R. L and Gurnett, D. A

Subjects
Geophysics
Abstract

In this study, the propagation and growth of whistler mode waves generated by electron beams within earth's bow shock is investigated using a planar model for the bow shock and a model electron distribution function. Within the shock, the model electron distribution function possesses a field-aligned T greater than T beam that is directed toward the magnetosheath. Waves with frequencies between about 1 and 100 Hz with a wide range of wave normal angles are generated by the beam via Landau and anomalous cyclotron resonances. However, because the growth rate is small and because the wave packets traverse the shock quickly, these waves do not attain large amplitudes. Waves with frequencies between about 30 and 150 Hz with a wide range of wave normal angles are generated by the beam via the normal cyclotron resonance. The ray paths for most of these waves are directed toward the solar wind although some wave packets, due to plasma convection travel transverse to the shock normal. These wave packets grow to large amplitudes because they spend a long time in the growth region. The results suggest that whistler mode noise within the shock should increase in amplitude with increasing upstream theta sub Bn. The study provides an explanation for the origin of much of the whistler mode turbulence observed at the bow shock.

Published
1985

37. Electrostatic hiss and the beam driven electron acoustic instability in the dayside polar cusp

Author

Tokar, R. L and Gary, S. P

Subjects
Geophysics
Abstract

In this study it is shown that the upward moving electron beams observed by DE-1 in the dayside polar cusp at 2 to 5 R sub E drive an electrostatic electron acoustic mode, rather than the whistler mode near resonance, as previously concluded. The characteristics of this instability are compared with the properties of hiss in the polar cusp observed by the Dynamics Explorer (DE-1) satellite. The hiss frequencies and funnel shaped frequency-time spectra are consistent with the electron acoustic mode. However, because the hiss often has a fluctuating magnetic field component near the axis of the funnel shape, the hiss is probably composed of both electron acoustic and whistler mode waves.

Published
1984

38. Power dissipation at slow-mode shocks in the distant geomagnetic tail

Author

Feldman, W. C, Baker, D. N, Bame, S. J, Birn, J, Hones, E. W., Jr, Tokar, R. L, and Schwartz, S. J

Subjects
Geophysics
Abstract

An estimate is made of the decreases in Poynting flux across slow shocks in the geomagnetic tail detected by the ISEE-3 spacecraft. An electron analyzer and a magnetometer recorded 26 of the events in January-February 1983. Two-dimensional electron velocity distributions parallel to the magnetic field across the shock transition characterized the data. The shocks were of relatively high strength, close to the switch-off limit, and displayed a large upstream Alfven Mach number. The Poynting flux decreased an average of 0.0018-0.0166 ergs/sq cm per sec. The power dissipated from lobe-magnetic energy density to plasma sheet convection across the shocks is estimated to be 5 x 10 to the 18th ergs/sec.

Published
1984

39. Whistler mode turbulence generated by electron beams in earth's bow shock

Author

Tokar, R. L, Gurnett, D. A, and Feldman, W. C

Subjects
Geophysics
Abstract

The Landau and cyclotron growth rates of whistler mode waves in the earth's bow shock are calculated by using electron distribution functions obtained with the fast plasma experiment on ISEE 2. Three electron distribution functions measured within the transition region of the shock are analyzed. These functions spontaneously generate whistler mode waves with plasma rest frame frequencies between about 0.1 and 100 Hz. The wave normal angles of the generated whistlers range from 0 deg to the resonance cone angle. Electromagnetic Landau resonance and/or cyclotron resonance contribute to wave growth over the range of observed velocity distributions. Waves generated by the normal cyclotron resonance have wave vectors directed toward the solar wind, while those generated by the Landau and the anomalous cyclotron resonances have vectors directed toward the magnetosheath. The preditions of the study are in qualitative agreement with observations of whistler mode waves near the earth's bow shock.

Published
1984

40. The proton concentration in the vicinity of the Io plasma torus

Author

Tokar, R. L, Gurnett, D. A, and Bagenal, F

Subjects
Lunar And Planetary Exploration
Abstract

Observations of lightning-generated whistlers conducted with the aid of the Voyager 1 plasma wave instrument during the March, 1979 encounter of Jupiter have been employed in numerous studies involving Jupiters's inner magnetosphere. In an investigation carried out by Tokar et al. (1982), the Voyager whistler observations were combined with heavy ion charged particle measurements in the Io torus to determine the light ion charge concentration along the whistler propagation paths. In the investigation, simple models were used for the plasma distribution along the propagation paths. In the present study, an improved model is used for the plasma distribution in the inner magnetosphere. The adopted model treats a plasma in diffusive equilibrium under the action of gravitational, centrifugal, and ambipolar electric field forces.

Published
1982

41. Light ion concentrations in Jupiter's inner magnetosphere

Author

Tokar, R. L, Gurnett, D. A, Shaw, R. R, and Bagenal, F

Subjects
Lunar And Planetary Exploration
Abstract

The light ion distribution in the inner Jovian magnetosphere is investigated using whistler dispersion measurements from the Voyager 1 plasma wave instrument and heavy ion plasma concentrations from the plasma instrument. Two models are developed for the light ion concentration over 14 L shells between L = 5.2 and 6.2, one giving a constant concentration along the field line and the other corresponding to an exponential density distribution. Due to heavy ion concentrations near the equator that are typically an order of magnitude larger than the light ion concentration, results obtained are mainly relevant to the light ion concentration outside of the torus. Light ion concentration near the equator ranges from about 1-10% of the heavy ion concentration, while outside the torus the light ions are the dominant species.

Published
1982

42. The volume emissivity of type III radio bursts

Author

Tokar, R. L and Gurnett, D. A

Subjects
Solar Physics
Abstract

The volume emissivity has been calculated for thirty-six type III solar radio bursts obtained from approximately 6.5 years of Imp 8 and ISEE 1 satellite data. Although the emissivities for these events vary over a large range, all the emissivities decrease rapidly with increasing heliocentric radial distance. The best fit power law for the emissivity, using the average power law index for all events analyzed, is J = J(0)R(-6.0), with J0 = 1.5 x 10 to the -24th W/cu m sr. This best fit emissivity is used to estimate the expected radial variation of the plasma oscillations responsible for the type III radio emissions.

Published
1980

43. Plasma oscillations and the emissivity of type III radio bursts

Author

Gurnett, D. A, Anderson, R. R, and Tokar, R. L

Subjects
Solar Physics
Abstract

Plasma wave electric field measurements with the solar orbiting Helios spacecraft have shown that intense electron plasma oscillations occur in association with type III solar radio bursts, thereby confirming a well known mechanism for generating solar radio emissions first proposed by Ginzburg and Zhelezniakov in 1958. In this paper the principal characteristics of these plasma oscillations are reviewed and the observed plasma oscillation intensities are compared with recent measurements of the emissivity of type III radio bursts. The observed emissivities are shown to be in good agreement with two current models for the conversion of electrostatic plasma oscillations to electromagnetic radiation.

Published
1980

45. Hybrid Simulations of Plasma-Neutral-Dust Interactions at Enceladus.

Author

Omidi, N., Russell, C. T., Tokar, R. L., Farrell, W. M., Kurth, W. S., Gurnett, D. A., Jia, Y. D., and Leisner, J. S.

Subjects
HYBRID computer simulation, SPACE plasmas, COSMIC dust, GASES, PLANETARY magnetospheres, COROTATING interaction regions, ENCELADUS (Satellite), SATURN (Planet)
Abstract

Through ejection from its southern hemisphere, Enceladus is a dominant source of neutral gas and dust in Saturn's inner magnetosphere. The interaction of the corotating plasma with the gas and dust modifies the plasma environment around Enceladus. We use 3-D hybrid (kinetic ions, fluid electrons) simulations to examine the effects of gas and dust on the nature of the interaction region and use Cassini observations to constrain their properties. [ABSTRACT FROM AUTHOR]

Published
2010
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46. Two distinct plasma and energetic ion distributions within the June 1998 magnetic cloud.

Author

Haggerty, D. K., Roelof, E. C., Smith, C. W., Ness, N. F., Skoug, R. M., and Tokar, R. L.

Subjects
CLOUDS, LAGRANGIAN points, PLASMA gases, HEAVY ions
Abstract

On June 24-25, 1998 a magnetic cloud was observed by ACE near the L1 Lagrangian point. The cloud contained what at first appears to be a single interplanetary magnetic field (IMF) flux rope. However, within this flux rope we found two distinct distributions of plasma and energetic particles. The first region of the cloud was populated with anti-sunward streaming energetic ions and exhibited a low alpha to proton ratio, typical of the solar wind. Halfway into the magnetic cloud a second and distinct spatial region was encountered, demarcated by a significant drop in the proton temperature, increase in the proton density, and increase in the alpha to proton ratio. This second region was also populated with "pancake" energetic ion pitch angle distributions (PADs). Therefore not only were the two regions within the flux rope occupied by two different plasma regimes, implying different coronal origins, but the ion anisotropies were completely different, (unidirectional vs. bidirectional), implying markedly different global topologies for the magnetic field lines. [ABSTRACT FROM AUTHOR]

Published
2000

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