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20050170004 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA Elastic Thickness Estimates for Coronae Associated with Chasmata on Venus Hoogenboom, T.; Martin, P.; Housean, G. A.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Coronae are large-scale circular tectonic features surrounded by annular ridges. They are generally considered unique to Venus and may offer insights into the differences in lithospheric structure or mantle convective pattern between Venus and Earth. 68% of all coronae are associated with chasmata or fracture belts. The remaining 32% are located at volcanic rises or in the plains. Chasmata are linear to arcuate troughs, with trough parallel fractures and faults which extend for 1000 s of kilometers. Estimates of the elastic thickness of the lithosphere (T(sub e)) have been calculated in a number of gravity/topography studies of Venus and for coronae specifically. None of these studies, however, have explored the dependence of T(sub e) on the tectonic history of the region, as implied from the interpretation of relative timing relationships between coronae and surrounding features. We examine the relationship between the local T(sub e) and the relative ages of coronae and chasmata with the aim of further constraining the origin and evolution of coronae and chasmata systems. Derived from text Coronas; Planetary Geology; Venus (Planet); Tectonics; Thickness; Elastic Properties; Landforms; Topography 20050170005 Los Alamos National Lab., NM, USA LIBS-based Detection of Geological Samples at Low Pressures (\h0.0001 torr) for Moon and Asteroid Exploration Harris, R. D.; Cremers, D. A.; Khoo, C.; Benelli, K.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document LIBS is under development for future use on surface probes to Mars [1-3]. Under simulated Mars atmospheric composition and pressure (7 torr, predominately CO2), LIBS has been shown useful for qualitative and quantitative analysis of geological samples at close and stand-off distances (19 m). Because of its many advantages compared to previously deployed and current in-use methods of elemental analysis (e.g. x-ray fluorescence, APXS), LIBS has potential for application to other planetary bodies. Of particular interest are the Moon and asteroids having very low ambient gas pressures at the surface. Because the laser plasma used by LIBS is sensitive to the surrounding atmosphere, it is important to determine analysis capabilities under these conditions. The results of a study of LIBS capabilities at low pressure is presented here for both in-situ and stand-off analysis. Plasma light, collected through the evacuated tube by a 10 cm diameter quartz lens, was focused onto a fiber optic cable. The light was directed into either the Derived from text Laser-Induced Breakdown Spectroscopy; Mars Atmosphere; Qualitative Analysis; Quantitative Analysis; Geology; Asteroids; Moon; Atmospheric Composition; Chemical Analysis 20050170006 Collegium Budapest/Inst. for Advanced Study, Budapest, Hungary Annual Change of Martian DDS-Seepages Horvaith, A.; Kereszturi, A.; Berezi, Sz.; Sik, A.; Pocs, T.; Gesztesi, A.; Ganti, T.; Szathmary, E.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The signs of surface water found by MGS (on MOC images), Mars Odyssey (neutron data) and Mars Express (spectral data) play important role in understanding surface processes especially probable life forms on Mars. There are signs of recent liquid water on Mars like the gullies formed probably during high obliquity and dark slope streaks which could be formed by gravitational mass movements or water seepage. We discovered and analysed a possible third group of phenomena presumably produced by liquid water on the surface, called DDS-seepage. These are originated at dark dune spots (DDS). (Dark dune spots appear in the defrosting surface in late winter early spring in the polar regions of Mars). Most of the DDS-seepages can be found at the steep slopes of the dark dunes in craters and the intercrater areas and we could study not only great number of these seepages but also could observe their changes from one Martian year to the other. Derived from text Dunes; Seepage; Mars Surface; Extraterrestrial Life; Annual Variations 355 20050170007 Brown Univ., Providence, RI, USA Regional Mid-Latitude Late Amazonian Valley Glaciers on Mars: Origin of Lineated Valley Fill and Implications for Recent Climate Change Head, James W.; Marchant, David r.; Agnew, Marshall C.; Fassett, Caleb I.; Kreslavsky, Mikhail A.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Among the hallmark morphologies of the highland-lowland boundary region in the northern mid-latitude Deuteronilus- Protonilus Mensae area (30-50oN, 315-350oW) is the fretted terrain (1), consisting of 1) debris aprons that surround many of the massifs and valley walls, and 2) lineated valley fill (LVF) that occurs on the floors of many of the valleys (2-14). The ages of these deposits are typically much younger than the adjacent plateau terrain or its breakup and the formation of the valleys themselves (e.g., 9, 14). The margins of the debris aprons consist of rounded and convex upward topography, and at Viking resolution the debris aprons and the valley fill can appear smooth and relatively homogeneous or, in contrast, can be characterized by closely spaced parallel ridges and grooves a few to several tens of meters high. These sets of parallel ridges have been interpreted to have formed both parallel and normal to valley and mesa walls. Some workers (e.g., 2) argue that the lineations form mostly normal to flow due to converging flow from debris aprons on opposite sides of valleys or mesas, while others (e.g., 4) argue that bending of ridges and grooves entering valleys from a side tributary supports flow in the direction parallel to the valley. Recent analysis shows variable downslope gradients suggesting that lateral flow was minimal (e.g., 11). All agree that the materials represent some sort of viscous flow processes, but opinions differ on the details of the mechanism; most authors call on processes of gravity-driven debris flow, assisted by ice or water in the interstices derived from either groundwater or diffusive exchange with the atmosphere (e.g., see 7, 10, 13-14). Some liken the process to rock-glacial flow (e.g., 2, 4) with the source of the lubricating agent being ice from atmospheric frost deposition and diffusion (2) or mobilized interstitial ground ice (4). Derived from text Climate Change; Glaciers; Mars Surface; Valleys; Highlands 20050170008 Lunar and Planetary Inst., Houston, TX, USA Loss Tangent Map of the Martian Surface: A Frequency Dependent Model for the Near Equatorial Regions Heggy, E.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The complex dielectric properties of the Martian surface sediments are a key parameter to understand the physical and geometrical parameters (such as density and roughness) of the Martian surface. In order to give an experimental description of the electric behavior of the Martian surface we have undertaken laboratory electromagnetic characterization in the frequency range 1 MHz to 3 GHz of the total set of minerals identified by TES. Volcanic rocks with a well defined mineralogy and petrology from potential terrestrial analogues sites have also been included in the study. Our primary objective is to quantify the range of electrical losses that may be encountered by the various Radar sounding and imaging experiments dedicated to map the physical properties of the Martian surface and subsurface searching mainly for underground water. The electromagnetic properties of these Mars-like materials are presented as a function of various geophysical parameters, such as porosity, bulk density and temperature. Using a basaltic Mars-like soil and soil density distribution provided by TES data. We integrated those measurements to form a primary Loss tangent and complex dielectric map of the Martian surface. Author Mars Surface; Planetary Mapping; Surface Roughness; Density Distribution; Dielectric Properties 20050170010 Deutsche Forschungsanstalt fuer Luft- und Raumfahrt, Berlin, Germany Beyond the Equilibrium Paradigm:Glacial Deposits in the Equatorial Regions of Mars Helbert, J.; Benkhoff, J.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945 Contract(s)/Grant(s): DFG-BE-1630/2; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document While Mars has been considered for a long time a dry place except for the early Noachian, this view has changed in recent years. This started mainly after the MOC imagery showed features like the gullies and morphological features which can be associated with glacial activity. Now the motion was discussed that at least small amounts of water or ice had been present in the recent past on Mars. Still, the common notion was that Mars today is a dry place. With the excellent dataset of the Gamma and Neutron spectrometer (GRS and HEND) on board of Mars Odyssey this view had to be corrected. The instrument 356 detected water abundance of at least 8wt% in the equatorial regions of Mars and this water is found within the first 2m below the surface, the penetration depth of the instrument. Author 2001 Mars Odyssey; Equatorial Regions; Mars Surface; Morphology; Penetration; Water 20050170012 Cologne Univ., Germany 3-Dimensional Chemical Analyses of Components in the Carbonaceous Chondrites Acfer 209 (CR) and Allende (CV) Hezel, D. C.; Palme, H.; Burkhardt, C.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Components of meteorites are 3-dimensional objects, which are usually studied in 2- dimensional thin sections. One exception are recent tomographic X-ray studies of Allende volumes by [1]. This method has the disadvantage of producing only BSE-like images without detailed chemical information: We have started to obtain 3-dimensional chemical data sets for meteoritic volumes. The results are important for a number of reasons: (1) Calculation of accurate chemical bulk compositions of chondrules and CAIs. Such data are relatively rare, but of particular interest for a variety of important questions, such as the chondrule - matrix complementarity described by [2]. A precise knowledge of chondrules compositions is crucial for chondrule forming mechanisms. Another question related to bulk chondrule compositions is the identification of chondrule precursor components and their origin [3]. Derived from text Carbonaceous Chondrites; Chemical Analysis; Chemical Composition; Chondrule; Meteoritic Composition; Meteorites 20050170014 Brown Univ., Providence, RI, USA Rheological Properties of Late-Stage Lava Flows on Ascraeus Mons: New Evidence from HRSC Hiesinger, H.; Head, J. W., III; Neukum, G., et al.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The Tharsis Montes, Arsia Mons, Pavonis Mons, and Ascraeus Mons, are large volcanic constructs that are part of the Tharsis rise. The Tharsis rise is commonly interpreted to be the result of a long-lasting large mantle upwelling that constructed the rise through a combination of uplift and magmatism (plutonism and volcanism). Of particular interest is the construction of the huge individual edifices, their ages, duration, episodicity, and rheology. Here we report on estimates of the rheological properties of late-stage lava flows on the eastern flank of Ascraeus Mons, Mars. Additional information is included in the original extended abstract. Author (revised) Rheology; Mars Volcanoes; Lava; Planetary Geology 20050170016 University of Northern Arizona, Flagstaff, AZ, USA Martian Central Pit Craters Hillman, E.; Barlow, N. G.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations Contract(s)/Grant(s): NAG5-12510; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Impact craters containing central pits are rare on the terrestrial planets but common on icy bodies. Mars is the exception among the terrestrial planets, where central pits are seen on crater floors ( floor pits ) as well as on top of central peaks ( summit pits ). Wood et al. [1] proposed that degassing of subsurface volatiles during crater formation produced central pits. Croft [2] argued instead that central pits might form during the impact of volatile-rich comets. Although central pits are seen in impact craters on icy moons such as Ganymede, they do show some significant differences from their martian counterparts: (a) only floor pits are seen on Ganymede, and (b) central pits begin to occur at crater diameters where the peak ring interior morphology begins to appear in terrestrial planet craters [3]. A study of craters containing central pits was conducted by Barlow and Bradley [4] using Viking imagery. They found that 28% of craters displaying an interior morphology on Mars contain central pits. Diameters of craters containing central pits ranged from 16 to 64 km. Barlow and Bradley noted that summit pit craters tended to be smaller than craters containing floor pits. They also noted a correlation of central pit craters with the proposed rings of large impact basins. They argued that basin ring formation fractured the martian crust and allowed subsurface volatiles to concentrate in these locations. They favored the model that degassing of the substrate during crater 357 formation was responsible for central pit formation due to the preferential location of central pit craters along these basin rings. Derived from text Mars Craters; Planetary Crusts; Planetary Geology; Structural Basins; Cratering; Mars Surface 20050170017 NASA Ames Research Center, Moffett Field, CA, USA, Virginia Univ., Charlottesville, VA, USA A Sedimentary Platform in Margaritifer Sinus, Meridiani Terra, and Arabia? Howard, A. D.; Moore, J. M.; Irwin, R. P., III; Craddock, R. A.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The Margaritifer-Meridiani-Arabia highlands-lowlands (H-L) transition has long been recognized as the most fluvially dissected region of Mars. However, the geomorphic evolution of this region remains enigmatic, particularly the origin of the layered deposits of Meridiani Terra and Arabia. We suggest that a portion of this regional slope served as a fluvial depositional platform during the late Noachian. Derived from text Geomorphology; Mars Surface; Geochronology; Sediments 20050170018 NASA Johnson Space Center, Houston, TX, USA, National High Magnetic Field Lab., Tallahassee, FL, USA A Model for Siderophile Element Distribution in Planetary Differentiation Humayun, M.; Rushmer, T.; Rankenburg, K.; Brandon, A. D.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Planetary differentiation begins with partial melting of small planetesimals.At low degrees of partial melting, a sulfur-rich liquid segregates by physical mechanisms including deformation-assisted porous flow. Experimental studies of the physical mechanisms by which Fe-S melts segregate from the silicate matrix of a molten H chondrite are part of a companion paper. Geochemical studies of these experimental products revealed that metallic liquids were in equilibrium with residual metal in the H chondrite matrix. This contribution explores the geochemical signatures produced by early stages of core formation. Particularly, low-degree partial melt segregation of Fe-S liquids leaves residual metal in the silicate matrix. Some achondrites appear to be residues of partial melting, e.g., ureilites, which are known to contain metal. The metal in these achondrites may show a distinct elemental signature. To quantify the effect of sulfur on siderophile element contents of residual metal we have developed a model based on recent parametrizations of equilibrium solid metal-liquid metal partitioning experiments. Derived from text Protoplanets; Siderophile Elements; Models; Geochemistry 20050170019 State Univ. of New York, Stony Brook, NY, USA Experimental Basalt Alteration at Low-pH: Implications for Weathering Relationships on Mars Hurowitz, J. A.; Tosca, N. J.; McLennan, S. M.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The chemistry of sedimentary rocks has long been utilized for the reconstruction of climatic, geographic and tectonic conditions in the Earth’s past. Naturally, the chemical and mineralogical changes that accompany weathering of the Earth’s granodioritic upper crust have been studied in great detail to better understand processes controlling the composition of sedimentary rocks. Weathering of basaltic rocks has been studied as well, and there is a reasonable understanding of the bulk chemical and mineralogical changes that accompany alteration of such rocks under terrestrial conditions. In contrast, Martian soils and altered rocks, which undoubtedly reflect the end product of some combination of physical and/or chemical alteration, do not appear to have evolved in a manner consistent with alteration of basalts as we know it on Earth. Here we present new insights into weathering processes on Mars utilizing the results of alteration experiments performed at low pH on synthetic basalts of Martian composition. Derived from text Basalt; Mineralogy; Planetary Geology; pH; Weathering; Mars Surface; Chemical Composition; Sedimentary Rocks 358 20050170021 Idaho State Univ., Pocatello, ID, USA Petrologic Evidence for Multiple, Chemically Evolved Magma Batches and Implications for Plains Volcanism on Earth and Mars Hughes, S. S.; Sakimoto, S. E. H.; Gregg, T. K. P.; Brady, S. M.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Small mafic shield volcanoes, abundant on the terrestrial planets, are the dominant landform in provinces characterized by plains-style volcanism. Exemplified on Earth within both oceanic and continental settings (e.g., Hawaii, Snake River Plains), they provide analogs for similar systems on other planets, especially Mars. Topographic analysis of individual Quaternary mafic shields on the eastern Snake River Plains (ESRP) of Idaho (the type area for plains-style volcanism demonstrates similarity in size, volume, and shape of these shields, as well as the vent spacing in the volcanic fields, with those of the Tempe Terra and Syria Planum regions of Mars. Geochemical and physical volcanologic studies of the ESRP show an emerging model of volcanic evolution that implies multiple small batches of magma derived from upper mantle sources. Various chemical trends are illustrated, exemplified by La vs. MgO, that argue for a system with variably evolved magma batches and possibly several magmatic sources. Petrologic modeling suggests that early magmas in the sequence form (layered?) sub-volcanic mafic intrusions that fractionate to evolved compositions. Later mafic magmas commingle with these earlier-derived intrusions, partially melt and assimilate late-stage fractionates, and erupt with chemically evolved, but isotopically un-evolved compositions. Derived from text Mars Volcanoes; Earth Surface; Petrology; Magma; Plains; Geochemistry; Mineralogy 20050170023 Deutsche Forschungsanstalt fuer Luft- und Raumfahrt, Berlin, Germany MERTIS: A Thermal Infrared Imaging Spectrometer for the Bepi-Colombo Mission Helbert, J.; Jessberger, E.; Benkhoff, J.; Arnold, G.; Banaszkiewicz, M.; Bischoff, A.; Blecka, M.; Calcutt, S.; Colangeli, L., et al.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Among the terrestrial planets, Mercury plays a special role. It is the smallest planet, the densest, the one with the probably oldest surface heavily gardened by space weathering, and shows large daily surface temperature variations. Understanding Mercury is crucial to develop a better understanding of the early processes in the inner solar system, of how our Earth formed, how it evolved, and how it interacts with the Sun. The ESA mission Bepi-Colombo consists of two probes - a planetary and a magnetospheric orbiter. The mission will be launched in 2012 and will reach Mercury in 2016. MERTIS is part of the payload of the planetary orbiter, focused on understanding the surface and interior of Mercury. Author Mercury Surface; Imaging Spectrometers; Thermal Mapping; Surface Temperature 20050170024 Institute of Space and Astronautical Science, Sagamihara, Japan Formation Process of Lunar Sinuous Rilles by Thermal Erosion of Basaltic Lava Flow Honda, Chikatoshi; Fujimura, Akio; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document One of the major negative relief features on the terrestrial planets and satellites are sinuous rilles, which origin has been still debated. They possess conspicuous morphological characteristics of meandering channels or valleys, which is decreasing of depth and width. Normal rilles are straight or gently curved and considered to be graben-type faults. Crater chains in sometimes form irregular fractures like a rille, but they are excluded from the definition of sinuous rille. Lunar sinuous rilles are occasionally found in the maria and mare-highland boundaries, and most of them are concentrated around the Mare Imbrium and in the Oceanus Procellarum. According to, lunar sinuous rilles have typical dimensions of 30 - 40 km length and of less than 1 km width. The origin of these features differs on each planet or satellite; hence, we investigated the origin of the lunar sinuous rille due to existence of information for consideration of the origin (e.g., chemical composition of rock and elevation of rim and floor of sinuous rille). Derived from text Lunar Maria; Lunar Topography; Basalt; Lava; Fluid Flow 359 20050170026 Maryland Univ., College Park, MD, USA Re-187 Os-187 Isotopic and Highly Siderophile Element Systematics of Group IVB Irons Honesto, J.; McDonough, W. F.; Walker, R. J.; McCoy, T. J.; Ash, R. D.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations Contract(s)/Grant(s): NNG04GG17G; NNG04GK52G; NAG5-13464; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Study of the magmatic iron meteorite groups permits constraints to be placed on the chemical and isotopic composition of parent bodies, and the timing of, and crystal-liquid fractionation processes involved in the crystallization of asteroidal cores. Here we examine Re-Os isotopic and trace elemental systematics of group IVB irons. Compared to most irons, the irons comprising this group are enriched in some of the most refractory siderophile elements, yet highly-depleted in most volatile siderophile elements. These characteristics have been attributed to processes such as high temperature condensation of precursor materials and oxidation in the parent body. Most recently it has been suggested that both processes may be involved in the chemical complexity of the group. Here, high precision isotopic and highly siderophile element (HSE) concentrations are used to further examine these possible origins, and the crystallization history of the group. In addition, we have begun to assess the possibility of relating certain ungrouped irons with major groups via multi-element, trace element modeling. In a companion abstract, the isotopic and trace element systematics of the ungrouped iron Tishomingo are compared with the IVB irons. Author Iron Meteorites; Magnetic Materials; Crystallization; Asteroids; Rhenium Isotopes; Osmium Isotopes 20050170027 California Univ., Los Angeles, CA, USA MET01210: Another Lunar Mare Meteorite (Regolith Breccia) with Extensive Pyroxene Exsolution, and Not Part of the YQ Launch Pair Huber, Heinz; Warren, Paul H.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document MET01210 has been classified as a lunar anorthositic breccia. Actually, it is a regolith breccia that contains more mare basalt than highland matter. The bulk Al2O3 content (microprobe fused-bead analysis in excellent agreement with analyses of the fusion crust) is 16.7 wt%, and the lithic and mineral clast components in thin section appear to be of mainly mare origin. From pyroxene mg vs. Ti/(Cr+Ti) zonation trends, the dominant mare component probably was a basalt (or diabase) with approx. 2.2 wt% TiO2. A highland component is definitely present, however. There are small aphanitic anorthositic impact melt clasts, and four of the five regolith spheroids identified to date are highly aluminous (24-35 wt% Al2O3). One of these, only 16 m in diameter, is of HASP composition, with 35 wt% Al2O3 and just 34 wt% SiO2 (Kempa and Papike looked for and did not find a relationship between spheroid size and frequency of HASP; our observations, most notably for lunaite QUE93069, consistently find HASP most abundant among the smallest highland spheroids and of course surface area/volume relationships should favor HASP development in relatively small objects.) The only mare or mainly mare spheroid is notably high in TiO2, 4.6 wt%, particularly considering that the Al2O3/FeO wt. ratio is 1.51, implying that the high-Ti mare component has been heavily diluted with highland matter. Additional information is included in the original extended abstract. Author (revised) Meteorite Parent Bodies; Lunar Rocks; Lunar Maria; Meteoritic Composition 20050170028 State Univ. of New York, Stony Brook, NY, USA Mechanically Produced Radical Species at Silicate Surfaces and the Oxidant in Martian Soils Hurowitz, J. A.; Tosca, N. J.; McLennan, S. M.; Schoonen, M. A. A.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The Labeled Release (LR) and Gas Exchange (GEx) experiments onboard the Viking Landers determined that the Martian soils at Chryse and Utopia Planitia contain unknown inorganic species of a highly oxidizing nature. The LR experiment demonstrated that the addition of a radioactive (14)C labeled nutrient solution to soil samples resulted in the production of (14)C labeled CO2 due to the breakdown of the organic species introduced. In the GEx experiments, humidification of a 1 cu cm Martian soil sample resulted in the production of as much as 790 nanomoles of O2 gas. The presence of a highly oxidizing species in the fine, wind-blown soils on Mars has obvious implications for both the stability of organic species in the Martian near-surface environment, as well as health implications for future human explorers who may be exposed to reactive dust particles through inhalation. At present, the nature of the oxidant in the Martian soils remains enigmatic. 360 Explanations for their reactivity have called on both exotic chemical compounds and/or unusual formation processes to produce oxidants. In the medical literature, specifically that related to silicosis and the toxicity of mineral dusts, it has long been known that the surfaces of freshly ground quartz particles are characterized by highly reactive radical species generated by the rupture of bonds during the grinding process. These surface radical species are stable in dry environments (e.g. the Martian surface) and are capable of producing H2O2 and other Reactive Oxygen Species (ROS) in solution. Here, we extend the study of the reactivity of freshly ground mineral surfaces to include the silicate minerals most commonly encountered in basalts and soils at the Martian surface: feldspar, clinopyroxene and olivine. We propose that the oxidizing nature of the Martian soils can be explained by the presence of such mineral surface radical species and propose mechanisms by which they might be formed under ambient conditions at the Martian surface. Additional information is included in the original extended abstract. Author (revised) Mars Environment; Planetary Composition; Toxicity; Oxidizers; Silicates; Radicals 20050170029 Arizona Univ., Tucson, AZ, USA Are Martian Crustal Magnetic Anomalies and Valley Networks Concentrated at Low Paleolatitudes? Hood, Lon L.; Harrison, Keith P.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document A broad spatial correlation between the Mars crustal magnetic field and the distribution of valley networks has previously been reported. Several possible explanations involving magmatic intrusions, hydrothermal alteration of the adjacent crust, and surface discharge of water have been suggested. In this paper, we investigate whether the distributions of both magnetic anomalies and valley networks may have been preferentially concentrated at low paleolatitudes. Such a concentration would be expected if melting of water ice and snow was a stronger source of surface valley erosion in the tropics and if hydrothermal alteration of crustal rocks played an important role in producing the unusually strong martian magnetic anomalies. Author Magnetic Anomalies; Mars (Planet); Crusts; Intrusion 20050170031 Colorado Univ., Boulder, CO, USA The Etched Terrain in Arabia Terra, Mars, is Tilted Hynek, B. M.; Phillips, R. J.; Lunar and Planetary Science XXXVI, Part 8; [2005]; 2 pp.; In English; See also 20050169945; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Light-toned bedrock has been observed at the Mars Exploration Rover (MER) Opportunity landing site. These outcrops are rich in a slew of mineral and textural signatures that suggest likely formation within water, including probable evaporites. Further, remote sensing data suggest that these outcrops are not a local phenomenon, rather, they are exposed across the entire hematite-bearing plain and well beyond (over an area \g 3 x 10(exp 5) sq km spanning 20 deg of longitude). Recent results from the OMEGA instrument on Mars Express show that the etched terrain mapped is rich in sulfates, thus corroborating the hypothesis that outcrops 100s to \g1000 km from Opportunity are diagenetically related. Moreover, there are potentially correlative terrains (with similar morphologic, thermal, and mineralogic expressions) up to 5,000 km away; including deposits within the Valles Marineris, Aram Chaos, and isolated exposures across NW Arabia Terra. We are still trying to understand the full extent of these deposits but it is becoming increasingly clear that copious amounts of water acted over an enormous region of Mars. Little is known about the timing of the putative sea and diagenesis of the layers. Because of its sedimentary and apparent subaqueous origin, the etched terrain was likely emplaced as horizontal to sub-horizontal strata. In this study we test for horizontality of the etched terrain layers and interpret the results in terms of the geological history of this region of Mars. Additional information is included in the original extended abstract. Author (revised) Mars Surface; Bedrock; Erosion; Floods; Terrain; Planetary Geology; Etching; Weathering 20050170551 Lunar and Planetary Inst., Houston, TX, USA Lunar and Planetary Science XXXVI, Part II [2005]; ISSN 1540-7848; In English; Lunar and Planetary Science XXXVI, 14-18 Mar. 2005, Houston, TX, USA; See also 20050170552 - 20050170639 Contract(s)/Grant(s): NCC5-679 Report No.(s): LPI-Contrib-1234-Pt-11; Copyright; Avail: CASI; C01, CD-ROM 361 Some topics covered: Implications of internal fragmentation on the structure of comets; Atmospheric excitation of mars polar motion; Dunite viscosity dependence on oxygen fugacity; Cross profile and volume analysis of bahram valles on mars; Calculations of the fluxes of 10-250 kV lunar leakage gamma rays; Alluvian fans on mars; Investigating the sources of the apollo 14 high-Al mare basalts; Relationship of coronae, regional plains and rift zones on venus; and Chemical differentiation and internal structure of europa and callisto. Derived from text Atmospheric Circulation; Chemical Composition; Comets; Mars Surface; Lunar Rays; Gamma Rays; Basalt 20050170554 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA The Core of the Moon - Molten or Solid? Khan, A.; Mosegaard, K.; Williams, J. G.; Lognonne, P.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050170551; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document While several studies beginning in the Apollo era and continuing up to the present have tried to detect the lunar core, either geochemically, geophysically or geologically [e.g. 1, 2, 3, 4], it has so far proven somewhat elusive. The unambiguous detection of the lunar core is of prime importance as it holds the potential of distinguishing between the various theories for the formation of the Moon. The theory which currently enjoys the greatest success is the giant impact model, which has the Moon forming about 4.5 Gyr ago from the debris produced when a Mars sized proto planet collided with the proto Earth [e.g. 5, 6]. Simulations reveal that the material from which the Moon is made up contains very little iron and consequently a lunar core, if it exists, should be small. Derived from text Lunar Core; Moon; Iron 20050170555 Notre Dame Univ., IN, USA Petrology of Nakhlite MIL 03346 Kinman, W. s.; Neal, C. R.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050170551; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The new Nakhlite meteorite MIL- 03346 was found in Antarctica at the Miller Range of the Transantarctic Mountain during the 2003-2004 field season. The exterior is approximately 60% covered by a black, wrinkled fusion crust. We were allocated two samples from the 712.5g sample-a2gwhole rock sample and thin section MIL03346,9. Unfortunately, the samples were received only 8 days before the abstract deadline so only a brief report comprised of mineralogical (electron microprobe) data is reported here. The major and trace element data, including platinum-group element abundances, will be reported at the conference. Author Nakhlites; Meteorites; Trace Elements 20050170556 Waseda Univ., Tokyo, Japan Global Mapping of Elemental Abundance on Lunar Surface by SELENE Gamma-Ray Spectrometer Kobayashi, M N.; Berezhnoy, A. A.; DUston, C.; Fujii, M.; Hasebe, N.; Hiroishi, T.; Kaneko, H.; Miyachi, T.; Mori, K.; Maurice, S., et al.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050170551; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Elemental composition on the surface of a planet is very important information for solving the origin and the evolution of the planet and also very necessary for understanding the origin and the evolution of solar system. Planetary gamma-ray spectroscopy is extremely powerful approach for the elemental composition measurement. Gamma-ray spectrometer (GRS) will be on board SELENE, advanced lunar polar orbiter, and employ a large-volume Ge detector of 252cc as the main detector [1]. SELENE GRS is, therefore, approximately twice more sensitivity than Lunar Prospector GRS, four times more sensitive than APOLLO GRS. The high sensitivity of SELENE GRS will enable us to map element abundances of O, Mg, Fe, Al, Si, Ti, K, Ca, Th, and U, with lower detection limit than the past missions. The Japanese lunar polar orbiter SELENE is scheduled for launch in 2007 and the GRS will observe the whole area of the moon including the polar region. Orbiting the GRS at 100 km in a nominal operation for one year will provide the global mapping of the chemical composition of lunar surface material for more elements than Lunar Prospector did [2]. Now, the flight model of SELENE GRS was built and will be qualified by 362 several environment test. Fig. 1 shows the schematic drawing. It shows an energy resolution of 3 keV @ 1.33 MeV in the GRS system. In this study, we will exhibit expected performance of SELENE GRS in lunar orbits predicted by preliminary Monte Carlo simulation results and describe scientific topics achievable by SELENE GRS. Derived from text Mapping; Gamma Ray Spectrometers; Lunar Maps; Lunar Surface; Planetary Surfaces; Abundance 20050170557 Oulu Univ., Finland Mars Express HRSC Analysis of Two Impact Craters in Terra Tyrrhena, Mars Korteniemi, J.; Kostama, V P.; Aittola, M.; Ohman, T.; Tormanen, T.; Lahtela, H.; Raitala, J.; Neukum, G.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050170551; Original contains color illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The surface of Mars is governed by division to smooth northern lowlands and intensely cratered highland terrain in the south. The cratering record indicates the age of the surface [e.g. 1,2], while individual craters original morphology hints to the target material at the time of impact [3]. Additionally, the craters provide natural sinks for later deposited materials, thus showing glimpses of the evolution of the region they reside in. In all, craters provide information on the local and areal evolution phases and processes. Derived from text Cratering; Mars Craters; Morphology; Mars Surface; Terrain 20050170558 Academy of Sciences (USSR), Moscow, USSR The Martian North Polar Cap Spirals are the Traces of an Ancient Ice Sheet Collapse Kostrikov, A. A.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050170551; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The surface of north polar cap of Mars is essentially heterogeneous unlike flat terrestrial ice sheets [1]. Troughs up to one kilometer deep with gently (no more 10-15 ) sloping are seen all over the ice cap. The unique feature of the trough system is its helical appearance (Fig. 1). Analogs of ice spiral structures are not known. The troughs have been attributed to the action of aeolian erosion [2-3], sublimation [4] or to ‘accublation’ hypothesis (glacial flow + sublimation + accumulation) [5-7]. It is supposed that an ice mass transfer occurs by sublimation from equatorward-facing slopes and subsequent accumulation on pole-facing slopes. No ideas on origin of spiral pattern have been moved forward with the exception of an attempt to explain trough revolving by combined effects of accublation and ice movement [8]. Derived from text Collapse; Ice; Glaciers; Polar Caps; Mars Surface 20050170560 Russian Academy of Natural Sciences, Moscow, Russia Wind-related Erosion Depressions Within a Small Impact Craters in Chryse and Elysium Planitiae on Mars Kuznetsov, I. V.; Kuzmin, R. O.; Greeley, R.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050170551; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document High resolution Mars Orbiter Camera (MOC) images [1] show wide variety of the aeolian features within the impact craters attributed to wind erosion and deposition: different types of bright and dark crater streaks, duneforms, bright transverse dunes, interacrater deposits, and rim scouring forms. The orientation of these aeolian features is consistent with the direction of current strong winds [2,3], while origin of some of them could be related with paleowind regime[4]. Here we present the results of study of unknown before phenomenon of the wind-related modification of the impact craters on Mars in the form of blowout hollows which have been found only in two places on Mars: much more in southern part of Chryse Planitia (CP) and less in south-western part of Elysium Planitia (EP). Derived from text Dunes; Mars Craters; Wind Erosion; Wind (Meteorology); Mars Surface 20050170561 Belgian Royal Observatory, Brussels, Belgium Atmospheric Excitation of Mars Polar Motion Karatekin, O.; Dehant, V.; deViron, O.; VanHoolst, T.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 1 pp.; In English; See also 20050170551; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document 363 [...]... ordinary stereo method Here we report the procedures and results of this modeling with AMICA (Asteroid Multiband Imaging Camera) and attitude of spacecraft, and distance between target asteroid and the spacecraft only Derived from text Three Dimensional Models; Sample Return Missions; Imaging Techniques; Cameras; Asteroid Missions; Shape Optimization 20050 170 574 Wien Univ., Austria The 2004 ICDP Bosumtwi... Drilling 20050 170 575 International Research School of Planetary Sciences, Pescara, Italy Morphology and Morphometry of Fluidized Ejecta Blankets: New Results from the Mars Express High Resolution Stereo Camera Komatsu, G.; Ori, G G.; DiLorenzo, S.; Rossi, A P.; Neukum, G.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050 170 551; Original contains color and black and white... Stereophotography; Mars Craters 20050 170 577 Arizona State Univ., Tempe, AZ, USA Palagonite-like Alteration Products on the Earth and Mars 2: Secondary Mineralogy of Crystalline Basalts Weathered Under Semi-Arid Conditions Kraft, M D.; Michalski, J R.; Sharp, T G.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050 170 551; Original contains black and white illustrations; Copyright;... with energies below approx 500 keV, and all elemental analyses have used higher-energy gamma rays, usually using only 372 lines The continuum can be used to study components of the lunar composition The lunar continuum is a good measure of the abundance of the natural radioactive elements K, U, and Th, using the continuum between 0.55 and 2 .75 MeV and between 450 and 480 keV Fourier transforms of continua... Spaceflight and Microgravity Directorate , which now forms the Human Spaceflight, Microgravity, and Exploration Directorate of ESA Derived from text European Space Agency; Mars Sample Return Missions; Life Support Systems; Space Flight; Orbital Rendezvous; Microgravity 20050 170 614 Tokyo Inst of Tech., Tokyo, Japan Presolar Silicate Grains from Primitive Carbonaceous Chondrites Y-81025, ALHA 77 3 07, Adelaide and. .. carbonaceous chondrites, Y-81025 (CO3.0), ALHA 77 3 07 (CO3.0), Adelaide (ungrouped, linked to CV-CO) and Acfer 094 (ungrouped, linked to CO-CM), which there are some agreement that the above chondrites are one of the most pristine chondrites Derived from text Carbonaceous Chondrites; Silicates; Metamorphism (Geology); Granular Materials 375 20050 170 615 Japan Aerospace Exploration Agency, Ibaraki, Japan... Raitala, J.; Neukum, G.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also 20050 170 551; Original contains color and black and white illustrations; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document The surface of Mars is divided into smooth northern lowlands and cratered southern highlands The cratering record indicates... glacial, fluvial and aeolian features, as well as a multitude of large and small impact craters Fresh large (greater than 5 km) Martian craters have typically raised rims, a central peak and/ or a peak ring and a generally flat floor with slumping on the inner walls The additional central or summit pits are common features on Martian craters, and generally related to high volatile content of the 377 target material... P D., Jr.; Lunar and Planetary Science XXXVI, Part 12; [2005]; 1 pp.; In English; See also 20050 170 942; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document Understanding the origin of the oldest lunar crust was a main scientific objective of the last three Apollo missions, 15, 16, and 17, all of which landed in or near highland exposures Starting... Apollo 15, the astronauts took hundreds of 70 mm surface photographs These pictures have been re-studied, and reveal pervasive layering in the lunar highland crust visited by the Apollo 15, 16, and 17 missions Additional information is included in the original extended abstract Author (revised) Lunar Crust; Highlands; Photogeology; Lunar Photography 20050 170 950 California Univ., Los Angeles, CA, USA . rock and elevation of rim and floor of sinuous rille). Derived from text Lunar Maria; Lunar Topography; Basalt; Lava; Fluid Flow 359 20050 170 026 Maryland Univ., College Park, MD, USA Re-1 87 Os-1 87. atmospheric composition and pressure (7 torr, predominately CO2), LIBS has been shown useful for qualitative and quantitative analysis of geological samples at close and stand-off distances (19. Geology; Etching; Weathering 20050 170 551 Lunar and Planetary Inst., Houston, TX, USA Lunar and Planetary Science XXXVI, Part II [2005]; ISSN 1540 -78 48; In English; Lunar and Planetary Science XXXVI,