Farside explorer: unique science from a mission to the farside of the moon   总被引：4，自引：0，他引：4  

David Mimoun  Mark A. Wieczorek  Leon Alkalai  W. Bruce Banerdt  David Baratoux  Jean-Louis Bougeret  Sylvain Bouley  Baptiste Cecconi  Heino Falcke  Joachim Flohrer  Raphael F. Garcia  Robert Grimm  Matthias Grott  Leonid Gurvits  Ralf Jaumann  Catherine L. Johnson  Martin Knapmeyer  Naoki Kobayashi  Alexander Konovalenko  David Lawrence  Mathieu Le Feuvre  Philippe Lognonné  Clive Neal  Jürgen Oberst  Nils Olsen  Huub R?ttgering  Tilman Spohn  Susanne Vennerstrom  Graham Woan  Philippe Zarka 《Experimental Astronomy》2012,33(2-3):529-585

Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of the Moon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded the primary differentiation and evolution of the Moon, it can be continuously monitored from the Earth–Moon L2 Lagrange point, and there is a complete lack of reflected solar illumination from the Earth. Farside Explorer will exploit these properties and make the first radio-astronomy measurements from the most radio-quiet region of near-Earth space, determine the internal structure and thermal evolution of the Moon, from crust to core, and quantify impact hazards in near-Earth space by the measurement of flashes generated by impact events. The Farside Explorer flight system includes two identical solar-powered landers and a science/telecommunications relay satellite to be placed in a halo orbit about the Earth–Moon L2 Lagrange point. One lander would explore the largest and oldest recognized impact basin in the Solar System— the South Pole–Aitken basin—and the other would investigate the primordial highlands crust. Radio astronomy, geophysical, and geochemical instruments would be deployed on the surface, and the relay satellite would continuously monitor the surface for impact events.  相似文献   

Discovery of an albite gneiss from the Ile de Groix (Armorican Massif, France): geochemistry and LA-ICP-MS U–Pb geochronology of its Ordovician protolith     

Afifé El Korh  Susanne Th. Schmidt  Michel Ballèvre  Alexey Ulianov  Olivier Bruguier 《International Journal of Earth Sciences》2012,101(5):1169-1190

For the first time, an albite orthogneiss has been recognised and dated within the HP–LT blueschist facies metabasites and metapelites of the Ile de Groix. It is characterised by a peraluminous composition, high LILE, Th and U contents, MORB-like HREE abundances and moderate Nb and Y values. A U–Pb age of 480.8?±?4.8?Ma was obtained by LA-ICP-MS dating of zircon and titanite. It is interpreted as the age of the magmatic emplacement during the Early Ordovician. Morphologically different zircon grains yield late Neoproterozoic ages of 546.6–647.4?Ma. Zircon and titanite U–Pb ages indicate that the felsic magmatism from the Ile de Groix is contemporaneous with the acid, pre-orogenic magmatism widely recognised in the internal zones of the Variscan belt, related to the Cambro-Ordovician continental rifting. The magmatic protolith probably inherited a specific chemical composition from a combination of orogenic, back-arc and anorogenic signatures because of partial melting of the Cadomian basement during magma emplacement. Besides, the late Devonian U–Pb age of 366?±?33?Ma obtained for titanite from a blueschist facies metapelite corresponds to the age of the HP–LT peak metamorphism.  相似文献   

Studies of aerosols advected to coastal areas with the use of remote techniques     

Tymon Zieliński  Tomasz Petelski  Przemysław Makuch  Agata Strzałkowska  Agnieszka Ponczkowska  Krzysztof M. Markowicz  Georgius Chourdakis  George Georgoussis  Susanne Kratzer 《Acta Geophysica》2012,60(5):1359-1385

This paper presents the results of the studies of aerosol optical properties measured using lidars and sun photometers. We describe two case studies of the combined measurements made in two coastal zones in Crete in 2006 and in Rozewie on the Baltic Sea in 2009. The combination of lidar and sun photometer measurements provides comprehensive information on both the total aerosol optical thickness in the entire atmosphere as well as the vertical structure of aerosol optical properties. Combination of such information with air mass back-trajectories and data collected at stations located on the route of air masses provides complete picture of the aerosol variations in the study area both vertically and horizontally. We show that such combined studies are especially important in the coastal areas where depending on air mass advection directions and altitudes the influence of fine or coarse mode (in this case possibly sea-salt) particles on the vertical structure of aerosol optical properties is an important issue to consider.  相似文献   

Archaeabacterial lipids in drill core samples from the Bosumtwi impact structure,Ghana     

Marina ESCALA  Antoni ROSELL‐MElÉ  Susanne FIETZ  Christian KOEBERL 《Meteoritics & planetary science》2008,43(11):1777-1782

Abstract— Meteorite impacts are associated with locally profound effects for microorganisms living at the terrestrial surface and the subsurface of the impact zone. The Bosumtwi crater in Ghana (West Africa) is a relatively young (1.07 Myr) structure with a rim‐to‐rim diameter of about 10.5 km. In a preliminary study targeting the subsurface microbial life in the impact structure, seven samples of the impact breccia from the central uplift of the Bosumtwi crater were analyzed for the presence of typical archaeal membrane‐lipids (GDGTs). These have been detected in four of the samples, at a maximum depth of 382 m below the lake surface, which is equivalent to 309 m below the surface sediment. The concentration of the GDGTs does not show a trend with depth, and their distribution is dominated by GDGT‐0. Possible origins of these lipids could be related to the soils or rocks predating the impact event, the hydrothermal system generated after the impact, or due to more recent underground water  相似文献   

Soil moisture dynamics at high temporal resolution in a semiarid Mediterranean watershed with scattered tree cover   总被引：1，自引：0，他引：1       下载免费PDF全文

Javier Lozano‐Parra  N. L. M. B. van Schaik  Susanne Schnabel  Álvaro Gómez‐Gutiérrez 《水文研究》2016,30(8):1155-1170

Subsurface water flows play a key role in the distribution of water and solutes and thereby in the water availability for plants. However, the characterization of different flow processes (i.e. matrix and preferential flow), the frequency and factors that cause them, is relatively rare. This characterization enables a better understanding of spatio‐temporal variability of water resources and allows for the design of models to be improved. Using a method based on the time derivative of soil moisture variation known as maximum wetting slope, types of soil wetting processes were classified and quantified. For this, capacitance sensors, which registered the volumetric water content at high temporal resolution (30 min) for more than two hydrological years, were installed at different depths and placed in soil moisture stations with different vegetation covers, lithology and topographic position. Results indicated that there is a general behaviour or pattern of soil moisture dynamics in the catchment with a dominant occurrence of slower soil wetting processes (>50%), caused by matrix flows, and a low occurrence of those faster processes (<30%), originated by preferential flows. Nevertheless, when the total volume of water is considered, preferential flow becomes the dominant process, so that the ecological role of both flow types becomes prominent in water‐limited environments. Statistical multivariate analyses based on data‐mining techniques proved that although both flow types depend on variables associated with precipitation and antecedent soil moisture conditions, faster soil wetting processes are mainly related to variables such as rainfall intensity and topography, while slower soil wetting processes are related to flow velocity, soils or vegetation. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Erratum to: Second California Assessment: integrated climate change impacts assessment of natural and managed systems. Guest editorial     

Guido Franco  Daniel R. Cayan  Susanne Moser  Michael Hanemann  Myoung-Ae Jones 《Climatic change》2012,113(3-4):1099-1100

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Significance of carbonaceous shales and vanadium geochemical haloes in the exploration for rock phosphate deposits in the southern Georgina Basin,central Australia     

Susanne SchmidWayne R. Taylor 《Journal of Geochemical Exploration》2009

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Textural and mineralogical biosignatures in an unusual microbialite from Death Valley, California     

Susanne Douglas  William Abbey  Randall Mielke  Pamela Conrad  Isik Kanik 《Icarus》2008,193(2):620-636

For in situ astrobiological studies of Mars or other planets, we must employ strategies that will enable us to verify whether our approach and prototype instruments are actually capable of distinguishing life from non-life. This must be done against a background of rigorously conducted scientific characterization of the environment or sample types being considered for measurement by the instruments under development. In this study we show how a combination of mineralogical and textural features can be considered a biosignature in an early Mars analogue environment, Death Valley, California. We propose that it is a combination of features in context of the geologic matrix which allows determination of biogenicity to be made. Polymineralic microbialites (organosedimentary formations constructed by microorganisms) from a spring pool at Badwater, within Death Valley National Park, are composed of alternating biogenic and abiogenic minerals in a distinct triplet sequence related to wet and dry seasons. A microbial community, occurring as a black biofilm, produced paired layers of two different mineral types: manganese oxyhydroxides and calcite. These biogenic layers are separated from the next pair by a gypsum layer and appear to be laid down in the wet season, with the gypsum (a mineral positively identified on Mars) precipitating in the dry part of the year, abiogenically (i.e., not dependent on microbial metabolic activity for its deposition). In addition, textural features (smaller grain size and less geometric morphology) unique to the biogenic vs the abiogenic layers, were consistently observed so that texture served as a biosignature in this environment.  相似文献   

Mojave Mars simulant—Characterization of a new geologic Mars analog     

Gregory H. Peters  Gregory H. Bearman  J. Anthony Smith  Susanne Douglas 《Icarus》2008,197(2):470-479

We have identified and characterized a basaltic Mars simulant that is available as whole rocks, sand and dust. The source rock for the simulant is a basalt mined from the Tertiary Tropico Group in the western Mojave Desert. The Mojave Mars Simulant (MMS) was chosen for its inert hygroscopic characteristics, its availability in a variety of forms, and its physical and chemical characteristics. The MMS dust and MMS sand are produced by mechanically crushing basaltic boulders. This is a process that more closely resembles the weathering/comminution processes on Mars where impact events and aerodynamic interactions provide comminution in the (relative) absence of water and organics. MMS is among the suite of test rocks and soils that was used in the development of the 2007/8 Phoenix Scout and is being used in the 2009 Mars Science Laboratory (MSL) missions. The MMS development team is using the simulant for research that centers on sampling tool interactions in icy soils. Herein we describe the physical properties and chemical composition of this new Mars simulant.  相似文献   

Mineralbestand und Genesis des Eisgarner Granits im niederösterreichischen Waldviertel     

Dr. Susanne Scharbert 《Mineralogy and Petrology》1966,11(3-4):388-412

Zusammenfassung Der jüngste Granit im österreichischen Moldanubikum ist der im nordwestlichen Waldviertel aufgeschlossene Eisgarner Granit.Das Gestein ist ein Zweiglimmergranit. Der Plagioklas (20–28 Vol.-%), selten zonar gebaut, hat einen durchschnittlichen An-Gehalt von 13%; daneben treten basischere Plagioklase (An bis 30%) als Einschlüsse im Mikroklin auf. Der Alkalifeldspat (25–38 Vol.-%) ist ein gegitterter, perthitisch entmischter Mikroklin mit Or 67–72%, Ab 24–28%, An 1,8–2,8%. Durch den Gehalt an Spurenelementen unterscheidet er sich stark von dem der älteren moldanubischen Granite. Die Triklinität liegt meist unter 0,90. Quarz tritt stellenweise als frühes Kristallisat auf, gehört aber im allgemeinen zu den Letztausscheidungen. Biotit (4–7 Vol.-%) bildel 2M-Polymorphe, ebenso Muskowit (6,5–7,5%), der entweder durch Reaktion von Andalusit mit der Schmelze oder aus Alkalifeldspat durch Reaktion mit der fluiden Phase hervorgegangen ist. Die Akzessorien Spinell, Rutil, Granat und Andalusit weisen darauf hin, daß der Granit durch Anatexis hochmetamorpher Gesteine (Silimanitgneise?) entstanden ist. Die Kristallisation verlief im Temperaturbereich zwischen ca 700° und 600°C bei einem Wasserdampfdruck von ca 5000 bar.

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Summary The youngest granite in the Moldanubian zone of Austria is theEisgarn granite which is exposed in the northwestern part of the Lower Austrian Waldviertel.The rock is a two-mica granite. The plagioclase (20–28 vol.-%) has an average An-content of 13% and shows only a weak zonary structure. Also more basic plagioclases (up to An 30) occur as inclusions in microcline. The alkalifeldspar (25–38 vol.-%) is a cross-hatched microcline perthite with the composition Or 67–72, Ab 24–28, An 1,8–2,8. It is distinguished from the microcline perthites of older granites by its content in trace elements. Its obliquity lies below 0,90. Partly the quartz is an early crystallisate, it is commonly a very late product, however. Biotite (4–7 vol.-%) forms the 2M polymorphe, as well as muscovite (6,5–7,5 vol.-%) which may develop by reaction of andalusite with the melt or from alkalifeldspar by reaction with the fluid phase. The accessories rutile, spinel, garnet and andalusite indicate a development of the granite by anatexis of high-metamorphic rocks (sillimanite-bearing gneisses?). Crystallization took place in the temperature range of 700° to 600°C under a water-vapor-pressure of 5000 bars.

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Herrn Prof. Dr.H. Leitmeier zum 80. Geburtstag gewidmet.  相似文献