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Sample records for agent petrified martian

  1. Stratigraphy of the upper Triassic Petrified Forest Member (Chinle Formation) in Petrified Forest National Park, Arizona, USA

    SciTech Connect

    Murry, P.A. )

    1990-09-01

    The Petrified Forest Member of the Triassic Chinle Formation in a Petrified Forest National Park, Arizona may be divided into a lower and upper unit by means of the Sonsela Sandstone Bed. Analysis of fossil vertebrates indicates that the Sonsela Sandstone Bed and upper Petrified Forest Member are characterized by a fauna distinct from that within the lower portion of the Petrified Forest Member. These faunas are believed to be of Norian and Carnian age respectively. Utilizing fossil vertebrates and certain lithostratigraphic units, especially the Sonsela Sandstone Bed and black forest tuff, exposures may be correlated within and between the Rainbow Forest, Blue Mesa, and Painted Desert areas of Petrified Forest National Park.

  2. Electrical Resistivity Tomography and Ground Penetrating Radar for locating buried petrified wood sites: a case study in the natural monument of the Petrified Forest of Evros, Greece

    NASA Astrophysics Data System (ADS)

    Vargemezis, George; Diamanti, Nectaria; Tsourlos, Panagiotis; Fikos, Ilias

    2014-05-01

    A geophysical survey was carried out in the Petrified Forest of Evros, the northernmost regional unit of Greece. This collection of petrified wood has an age of approximately 35 million years and it is the oldest in Greece (i.e., older than the well-known Petrified Forest of Lesvos island located in the North Aegean Sea and which is possibly the largest of the petrified forests worldwide). Protection, development and maintenance projects still need to be carried out at the area despite all fears regarding the forest's fate since many petrified logs remain exposed both in weather conditions - leading to erosion - and to the public. This survey was conducted as part of a more extensive framework regarding the development and protection of this natural monument. Geophysical surveying has been chosen as a non-destructive investigation method since the area of application is both a natural ecosystem and part of cultural heritage. Along with electrical resistivity tomography (ERT), ground penetrating radar (GPR) surveys have been carried out for investigating possible locations of buried fossilized tree trunks. The geoelectrical sections derived from ERT data in combination with the GPR profiles provided a broad view of the subsurface. Two and three dimensional subsurface geophysical images of the surveyed area have been constructed, pointing out probable locations of petrified logs. Regarding ERT, petrified trunks have been detected as high resistive bodies, while lower resistivity values were more related to the surrounding geological materials. GPR surveying has also indicated buried petrified log locations. As these two geophysical methods are affected in different ways by the subsurface conditions, the combined use of both techniques enhanced our ability to produce more reliable interpretations of the subsurface. After the completion of the geophysical investigations of this first stage, petrified trunks were revealed after a subsequent excavation at indicated

  3. Petrified Ears” in Secondary Adrenal Insufficiency

    PubMed Central

    Goswami, Soumik; Chakraborty, Partha Pratim; Ghosh, Sujoy; Chowdhury, Subhankar

    2016-01-01

    Petrification of the auricle, a rarely encountered clinical entity usually results from ectopic calcification of the auricular cartilages and manifests as rigid ear. The underlying pathogenesis remains ambiguous with several proposed hypotheses till date. Auricular calcification may be the sole cutaneous marker of underlying endocrinopathy at times. Adrenal insufficiency is the most common endocrinological disorder to be associated with such stiff ears and it has been described in both primary as well as secondary forms of the disease. We present here a 30-year-old man whose clinical condition deteriorated following levothyroxine supplementation and the presence of “petrified ears” ultimately provided a clue to the diagnosis of associated secondary adrenal insufficiency. PMID:27042511

  4. A Mixed Methods Analysis of the Effects of an Integrative Geobiological Study of Petrified Wood in Introductory College Geology Classrooms

    ERIC Educational Resources Information Center

    Clary, Renee M.; Wandersee, James H.

    2007-01-01

    Mixed methods research conducted across three semesters in introductory college geology classes (n=187, 190, 138) attempted to ascertain whether integrated study of petrified wood could serve as a portal to improved student geobiological understanding of fossilization, geologic time, and evolution. The Petrified Wood Survey[TM] was administered as…

  5. Petroleum surface oil seeps from Palaeoproterozoic petrified giant oilfield

    NASA Astrophysics Data System (ADS)

    Melezhik, V.; Fallick, A.; Filippov, M.; Lepland, A.; Rychanchik, D.; Deines, Yu.; Medvedev, P.; Romashkin, A.; Strauss, H.

    2009-04-01

    Evidence of petroleum generation and migration has been previously reported from rocks dating as early as 3.25 Ga. Micron-size carbonaceous streaks and bitumen micronodules were found in abundance in Archaean rocks across the Pilbara craton in Australia suggesting pervasive petroleum generation and migration. However, none of the Archaean petroleum deposits has been reported to be preserved in quantity due to destructive effects of deformation and thermal obliteration during metamorphism. During the Palaeoproterozoic, unprecedented accumulation of Corg-rich rocks worldwide, known as the 2.0 Ga Shunga Event, occurred during the early stage of progressive oxidation of terrestrial environments, and in the aftermath of the Lomagundi-Jatuli isotopic event, which based on the magnitude and duration of positive d13C was the greatest perturbation of the global carbon cycle in Earth history. C. 2.0 Ga Zaonezhskaya Formation (ZF) rocks from the Onega Basin in Russian Fennoscandia contain evidence for substantial accumulation and preservation of organic matter (up to 75 wt.-% total organic carbon) with an estimated original petroleum potential comparable to a modern supergiant oilfield. The basin contains a uniquely preserved petrified oilfield including evidence of oil traps and oil migration pathways. Here, we report the discovery of the surface expression of a migration pathway, along which petroleum was flowing from the sub-surface. This surface oil seep, the first occurrence ever reported from the Palaeoproterozoic, appears as originally bitumen clasts redeposited in Palaeoproterozoic lacustrine turbidites of the Kondopozhskaya Formation. The d13Corg of clastic pyrobitumen ranges between -35.4 and -36.0 per mill (n = 14) which is within the range of interbed- and vein-trapped fossil oil (-46 and -24 per mill), suggesting similar source. Biogenic organic matter, whose isotopic composition was modified during thermal maturation, is the likely source for the migrated

  6. Martian sediments and sedimentary rocks

    NASA Technical Reports Server (NTRS)

    Markun, C. D.

    1988-01-01

    Martian sediments and sedimentary rocks, clastic and nonclastic, should represent a high priority target in any future return-sample mission. The discovery of such materials and their subsequent analysis in terrestrial laboratories, would greatly increase the understanding of the Martian paleoclimate. The formation of Martian clastic sedimentary rocks, under either present, low-pressure, xeric conditions or a postulated, high-pressure, hydric environment, depends upon the existence of a supply of particles, various cementing agents and depositional basins. A very high resolution (mm-cm range) photographic reconnaissance of these areas would produce a quantum jump in the understanding of Martian geological history. Sampling would be confined to more horizontal (recent) surfaces. Exploration techniques are suggested for various hypothetical Martian sedimentary rocks.

  7. Martian ages

    NASA Technical Reports Server (NTRS)

    Neukum, G.; Hiller, K.

    1981-01-01

    Four discussions are conducted: (1) the methodology of relative age determination by impact crater statistics, (2) a comparison of proposed Martian impact chronologies for the determination of absolute ages from crater frequencies, (3) a report on work dating Martian volcanoes and erosional features by impact crater statistics, and (4) an attempt to understand the main features of Martian history through a synthesis of crater frequency data. Two cratering chronology models are presented and used for inference of absolute ages from crater frequency data, and it is shown that the interpretation of all data available and tractable by the methodology presented leads to a global Martian geological history that is characterized by two epochs of activity. It is concluded that Mars is an ancient planet with respect to its surface features.

  8. Martian ages

    NASA Astrophysics Data System (ADS)

    Neukum, G.; Hiller, K.

    1981-04-01

    Four discussions are conducted: (1) the methodology of relative age determination by impact crater statistics, (2) a comparison of proposed Martian impact chronologies for the determination of absolute ages from crater frequencies, (3) a report on work dating Martian volcanoes and erosional features by impact crater statistics, and (4) an attempt to understand the main features of Martian history through a synthesis of crater frequency data. Two cratering chronology models are presented and used for inference of absolute ages from crater frequency data, and it is shown that the interpretation of all data available and tractable by the methodology presented leads to a global Martian geological history that is characterized by two epochs of activity. It is concluded that Mars is an ancient planet with respect to its surface features.

  9. Pigmenting agents in Martian soils: inferences from spectral, Mossbauer, and magnetic properties of nanophase and other iron oxides in Hawaiian palagonitic soil PN-9.

    PubMed

    Morris, R V; Golden, D C; Bell JF 3rd; Lauer, H V; Adams, J B

    1993-10-01

    We have examined a Hawaiian palagonitic tephra sample (PN-9) that has spectroscopic similarities to Martian bright regions using a number of analytical techniques, including Mossbauer and reflectance spectroscopy, X-ray diffraction, instrumental neutron activation analysis, electron probe microanalysis, transmission electron microscopy, and dithionite-citrate-bicarbonate extraction. Chemically, PN-9 has a Hawaiitic composition with alkali (and presumably silica) loss resulting from leaching by meteoric water during palagonitization; no Ce anomaly is present in the REE pattern. Mineralogically, our results show that nanophase ferric oxide (np-Ox) particles (either nanophase hematite (np-Hm) or a mixture of ferrihydrite and np-Hm) are responsible for the distinctive ferric doublet and visible-wavelength ferric absorption edge observed in Mossbauer and reflectivity spectra, respectively, for this and other spectrally similar palagonitic samples. The np-Ox particles appear to be imbedded in a hydrated aluminosilicate matrix material; no evidence was found for phyllosilicates. Other iron-bearing phases observed are titanomagnetite, which accounts for the magnetic nature of the sample; olivine; pyroxene; and glass. By analogy, np-Ox is likely the primary pigmenting agent of the bright soils and dust of Mars.

  10. Pigmenting agents in Martian soils: inferences from spectral, Mossbauer, and magnetic properties of nanophase and other iron oxides in Hawaiian palagonitic soil PN-9

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Golden, D. C.; Lauer, H. V. Jr; Adams, J. B.

    1993-01-01

    We have examined a Hawaiian palagonitic tephra sample (PN-9) that has spectroscopic similarities to Martian bright regions using a number of analytical techniques, including Mossbauer and reflectance spectroscopy, X-ray diffraction, instrumental neutron activation analysis, electron probe microanalysis, transmission electron microscopy, and dithionite-citrate-bicarbonate extraction. Chemically, PN-9 has a Hawaiitic composition with alkali (and presumably silica) loss resulting from leaching by meteoric water during palagonitization; no Ce anomaly is present in the REE pattern. Mineralogically, our results show that nanophase ferric oxide (np-Ox) particles (either nanophase hematite (np-Hm) or a mixture of ferrihydrite and np-Hm) are responsible for the distinctive ferric doublet and visible-wavelength ferric absorption edge observed in Mossbauer and reflectivity spectra, respectively, for this and other spectrally similar palagonitic samples. The np-Ox particles appear to be imbedded in a hydrated aluminosilicate matrix material; no evidence was found for phyllosilicates. Other iron-bearing phases observed are titanomagnetite, which accounts for the magnetic nature of the sample; olivine; pyroxene; and glass. By analogy, np-Ox is likely the primary pigmenting agent of the bright soils and dust of Mars.

  11. Martian seismicity

    NASA Technical Reports Server (NTRS)

    Phillips, Roger J.; Grimm, Robert E.

    1991-01-01

    The design and ultimate success of network seismology experiments on Mars depends on the present level of Martian seismicity. Volcanic and tectonic landforms observed from imaging experiments show that Mars must have been a seismically active planet in the past and there is no reason to discount the notion that Mars is seismically active today but at a lower level of activity. Models are explored for present day Mars seismicity. Depending on the sensitivity and geometry of a seismic network and the attenuation and scattering properties of the interior, it appears that a reasonable number of Martian seismic events would be detected over the period of a decade. The thermoelastic cooling mechanism as estimated is surely a lower bound, and a more refined estimate would take into account specifically the regional cooling of Tharsis and lead to a higher frequency of seismic events.

  12. Martian Habitability

    NASA Astrophysics Data System (ADS)

    Gómez, F.

    2012-09-01

    Due to the reported Mars surface environmental conditions (Klein, 1978) (oxidative stress, high UV radiation levels, etc.) the possibility for life development in the surface of the red planet is very small. The identification of water-ice on the subsurface on Mars by the Thermal Emission Spectrometer onboard of the Mars Odyssey (Kieffer and Titus, 2001) and from the High Energy Neutron Detector (Litvak, et al., 2006) has important astrobiological connotations, because in addition to be a potential source for water, these locations are shielding habitats against the harsh conditions existing on the planet, like UV radiation (Gomez, et al., 2007; Gomez, et al., 2012). Martian habitability potential could change in particular located micro-niches. Salt deliquescence and hard environmental parameters modification could be relevant for life under protected niches. An example could be endolithic niches inside salt deposits used by phototrophs for taking advantage of sheltering particular light wavelengths. Similar acidic salts deposits are located in Río Tinto extreme environment with shelter life forms which are difficult to localize by eye. Techniques for its localization and study during space missions are needed to develop. Extreme environments are good scenarios where to test and train those techniques and where hypothetical Astrobiological space missions could be simulated for increasing possibilities of micro niches identification. Here we will report some experiments of bacteria exposition to Martian surface conditions in Mars Simulation chamber. Bacteria were shelter and exposed included in simulated salty endolithic micro niches. High percentage of bacteria resistance and adaptation to harsh extreme those conditions was reported (Gómez, F. et al., 2010). These results were used to develop and implement a Habitability Index to study Martian habitability during the next MSL mission to Mars landed on August 2012 on the surface of the red planet.

  13. Martian Fingerprints

    NASA Technical Reports Server (NTRS)

    2005-01-01

    9 April 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows patterned ground on the martian northern plains. The circular features are buried meteor impact craters; the small dark dots associated with them are boulders. The dark feature at left center is a wind streak.

    Location near: 75.1oN, 303.0oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

  14. Petrified Forest National Park Invasive Plant Species Survey and Mapping; 2002-2005

    USGS Publications Warehouse

    Thomas, Kathryn A.; Hunt, Randall; Arundel, Terry R.; Guertin, P.

    2009-01-01

    We conducted a survey for invasive nonnative plant species at Petrified Forest National Park from 2002 through 2005. The survey employed a unique sampling design consisting of a grid of consecutive one-hectare cells as the sampling units. Our use of predetermined sampling units allowed all observations to be referenced to a fixed area with geographic coordinates that easily transferred to a geographic information system. Our field team surveyed 2,730 sampling units in three select areas for at least 1 year and 879 sampling units for 4 years. During this period we identified 40 different invasive plant species; more than half the invasive plants (22 species) were annual forbs and grasses. Four invasive plant species occurred in 25 percent or more of all sampling units observed in one or more years: Bromus tectorum, Erodium cicutarium, Salsola tragus, and Sisymbrium altissimum. Salsola tragus was the most abundant species in all years and occurred in more than 55 percent of all sampling units surveyed each year.

  15. Adsorption of methylene blue from aqueous solution on pyrolyzed petrified sediment.

    PubMed

    Aroguz, Ayse Z; Gulen, J; Evers, R H

    2008-04-01

    The adsorption kinetics of methylene blue on pyrolyzed petrified sediment (PPS) has been performed using a batch-adsorption technique. The effects of various experimental parameters, such as initial dye concentration, contact time, and temperature were investigated. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data. The best correlation coefficient was obtained using the pseudo first-order kinetic model, which shows that the adsorption of methylene blue followed the pseudo-first-order rate expression and the rate constants were evaluated. The Langmuir and Freundlich adsorption isotherm models were applied to describe the equilibrium isotherms and the isotherm constants were determined. It was found that the data fitted well to Langmuir and Freundlich models. The activation energy of adsorption was also evaluated for the adsorption of methylene blue onto pyrolyzed sediment. It was found about 8.5 kJ mol(-1). Thermodynamics parameters DeltaG(o), DeltaH(o), DeltaS(o) were calculated, indicating that this process can be spontaneous and endothermic. The adsorption enthalpy and entropy were found as 14-18.5 kJ mol(-1) and 52.8-67 J mol(-1) K(-1), respectively. The results obtained from the adsorption process using PPS as adsorbent was subjected to student's t-test.

  16. Weathering of Martian Evaporites

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; Velbel, M. A.; Thomas-Keprta, K. L.; Longazo, T. G.; McKay, D. S.

    2001-01-01

    Evaporites in martian meteorites contain weathering or alteration features that may provide clues about the martian near-surface environment over time. Additional information is contained in the original extended abstract.

  17. Investigations in Martian Sedimentology

    NASA Technical Reports Server (NTRS)

    Moore, Jeffrey M.

    1998-01-01

    The purpose of this report is to investigate and discuss the Martian surface. This report was done in specific tasks. The tasks were: characterization of Martian fluids and chemical sediments; mass wasting and ground collapse in terrains of volatile-rich deposits; Mars Rover terrestrial field investigations; Mars Pathfinder operations support; and Martian subsurface water instrument.

  18. The vegetation and climate of a Neogene petrified wood forest of Mizoram, India

    NASA Astrophysics Data System (ADS)

    Tiwari, R. P.; Mehrotra, R. C.; Srivastava, Gaurav; Shukla, Anumeha

    2012-11-01

    Eleven fossil woods belonging to seven families are described from a petrified wood forest of Mizoram. This fossil assemblage is derived from sediments belonging to the Tipam Group considered to be Late Miocene-Early Pliocene in age. The modern counterparts of the identified taxa are: Gluta L., Mangifera L. (Anacardiaceae), Bursera Jacq. ex L. (Burseraceae), Terminalia L. (Combretaceae), Shorea Roxb. (Dipterocarpaceae), Cynometra Linn., Dalbergia L. f., Millettia Wight et Arn.-Pongamia Vent, Ormosia Jacks. (Fabaceae), Artocarpus Forst. (Moraceae) and Madhuca Gmelin. (Sapotaceae). The genus Dalbergia is described for the first time from India. The modern environmental tolerances of the above taxa indicate the existence of a tropical warm and humid climate in Mizoram during the depositional period. The reconstructed climate data using Coexistence Approach (CoA) based on palaeoflora database of Mosbrugger and Utescher, along with other published data sets indicates an MAT (mean annual temperature) of 26.1-27.7 °C, a mean temperature of the warmest month (WMT) of 25.4-28.1 °C, a mean temperature of the coldest month (CMT) of 25.6-26 °C, and a mean annual precipitation (MAP) of 3180-3263 mm. These climatic interpretations are congruent with the data obtained from the anatomical features of all the fossil taxa. As all the fossil taxa possess diffuse porous wood, they further indicate a tropical climate with little seasonality. The majority of the taxa in the fossil assemblage generally have large vessels and simple perforation plates which indicate high precipitation. The present study provides vital evidence of floral exchange or migration between India and southeast Asia.

  19. Fluvial sedimentology of a Mesozoic petrified forest assemblage, Shishu Formation, Junggar foreland basin, Xinjiang, China

    SciTech Connect

    McKnight, C.L.; Gan, O.; Carroll, A.R.; Dilcher, D.; Zhao, M.; Liang, Y.H.; Graham, S.A.

    1988-02-01

    The Upper Jurassic(.) Shishu Formation of the eastern Junggar basin, Xinjiang, northwest China, is a fluvial sand unit containing an important assemblage of well-preserved, silicified tree trunks and rooted stumps. Numerous logs, up to 83 ft (25.5 m) long, occur at several levels within a 33.6-ft (10.3 m) stratigraphic section of fluvial sand, gravel, and mud and several paleosol horizons. The uppermost logbearing layer includes a number of rooted tree stumps in growth position, with diameters of up to 8 ft (2.5 m). The maximum root length observed is 40 ft (12.3 m). The trees have been identified by Chinese paleontologists as Cupressinoxylon. The petrified forest assemblage is preserved on the northeast margin of the Mesozoic Junggar foreland basin, a large continental basin subsiding under thrust loading from the south. Logs found within channel gravel units are oriented with their log axes parallel to the channel axis. Sedimentary structures, including epsilon and trough cross-stratification and imbricated channel gravels, indicate paleocurrent flow generally to the south, toward the basin center. The size of the logs suggests the presence of a major fluvial system. The epsilon cross-sets suggest a channel depth of 26 ft (8 m). The oriented silicified logs and their enclosing clastic sediments provide important information on the depositional systems active on the northeastern margin of the Junggar basin in the Late Jurassic(.) time. Hopefully, further detailed study of the fossil trees, including the spacing of the rooted stumps, will provide new information on the paleoecology of Mesozoic forests and the climatic conditions prevailing in the region at the time of deposition.

  20. Paleocene paleosols of the petrified forests of Theodore Roosevelt National Park, North Dakota: A Natural Experiment in compound pedogenesis

    SciTech Connect

    Fastovsky, D.E. ); McSweeney, K. )

    1991-02-01

    The Petrified Forest Plateau of Theodore Roosevelt National Park (TRNP) in western North Dakota provides an excellent setting for exploring the influence of ancient, exhumed land surfaces upon modern ones. Here, a sequence of Paleocene rocks preserves a succession of ancient terrestrial land surfaces characterized by fine-grained, laminated sedimentary rocks and organic-rich horizons. These exposures are dominantly finer-grained than the rest of the sedimentary rocks in the Park, and represent a region inferred to have been distal to the bulk of an aggradational fluvial system. Water was abundant in the Plateau region, and during much of the time the landscapes were submerged. At least twice, large forests developed in soils forming on floodplain sediments. These paleosols are characterized by organic surficial horizons and gleyed subsoils. Coniferous stumps from two successive forests constitute the Petrified Forest preserved in TRNP today. The modern environments of the Petrified Forest Plateau contrast sharply with those of the ancient; they are characterized by intense seasonality, semi-aridity, steep topography, a degradational land surface, and low organic productivity. Despite this, the modern soils show an imprint deriving from ancient environmental conditions that is as strong as any imprint from Holocene pedogenic processes; the soils that are presently forming retain much of the waterlogged features of the Paleocene soils. While it is clear that soils do respond to environments, it is also clear that the response may vary, depending upon the nature of the soil material and morphologies inherited. Here, the development of a gleyed morphology has proven largely irreversible.

  1. Enigmatic organosiliceous rocks in the 2000 Ma petrified oil field in Russian Fennoscandia

    NASA Astrophysics Data System (ADS)

    Deines, Yu.; Melezhik, V.; Lepland, A.; Filippov, M.; Romashkin, A.; Rychanchik, D.

    2009-04-01

    The c. 2000 Ma, 900 m-thick, Zaonezhskaja Formation in the Onega basin, Russian Fennoscandia, contains one of the greatest accumulations of organic matter (OM) in the Early Precambrian. It also represents a unique preservation of a supergiant petrified oil field. Zaonezhskaja Formation rocks are greenschist-facies volcaniclastic greywackes (distal turbidites), dolostone and limestones, mafic tuffs and lavas intruded by numerous mafic sills. Several sedimentary beds are enriched in OM with the overall content of total organic carbon (TOC) ranging from 0.1 to 16 wt.% whereas d13C varies between -44 and -17 per mil(V-PDB). The formation contains plentiful evidence of generation and migration of oil (now petrified) as well as oil traps. Results of geophysical surveys combined with drillcore data, including results recently obtained within the framework of the Fennoscandian Arctic Russia - Drilling Early Earth Project (FAR-DEEP), revealed numerous bodies of organosiliceous rocks (OSR) containing mainly silica (c. 57 wt.% SiO2), organic carbon (up to 40 wt.%), Al2O3 (c. 5 wt.%), S (c. 2 wt.%), and minor K, Mg, Fe, Ca and Ti. d13C of the OSR ranges between -40 and -20 per mil. The OSR form crudely stratified beds, cupola-like bodies or veins. The cupola-like bodies show cross-cutting (intrusive) contacts with the host turbiditic greywackes, reach thicknesses of 120 m with a lateral extent of several hundreds of metres. Veins are a few tens of centimetres thick. The OSR show close spatial association with gabbro sills. Although different fabrics have been recognised in the OSR, syngenetic macro- and microbreccias per se are the most common rock types. Fragments of different sedimentary rocks, as well as those with alternating C-rich and C-poor concentric lamina are present. The latter suggests precipitation from hydrothermal fluids. The nature of the OSR remains enigmatic. Several models have been advanced for explanation of origin of the OSR. However, neither of them

  2. Reduced Martian Carbon: Evidence from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, SImon J.; Pillinger, COlin T.; Wright, Ian P.; Verchovsky, A. P.

    2010-01-01

    Identification of indigenous reduced carbon species on Mars has been a challenge since the first hypotheses about life on Mars were proposed. Ranging from the early astronomical measurements to analyses of samples from the Martian surface in the form of Martian meteorites. The first direct attempt to analyze the carbon species on the surface was in 1976 with the Viking GC-MS in-situ experiment which gave inconclusive results at two sites on Mars [1]. With the recognition in 1983 that samples of the Martian surface were already present on Earth in the form of Martian meteorites by Bogard and Johnson [2] new opportunities became available for direct study of Mars's samples in te rlraesbtrioalratories. Carbon isotopic compositional information suggested a reduced carbon component was present in the Martian meteorites [3-5]. Polycyclic aromatic hydrocarbons associated with carbonate globules in ALH84001 were later identified [6,7]. Jull et al [8] noted that an insoluble component was present within Nakhla and more than 75% of its C lacked any 14C, which is modern-day carbon contaminant. This carbon fraction was believed to be either indigenous (i..e. Martian) or ancient meteoritic carbon phase. Within the fractures of Nakhla and ALH84001, Fisk et al [9,10] identified reduced carbon-enriched areas. Gibson et al. [11] using a combination of NanoSIMS, Focused Electron microscopy, Laser Raman Spectroscopy and Stepped-Combustion Static Mass Spectrometry analyses the presence of possible indigenous reduced carbon components within the 1.3 Ga old Nakhla.

  3. Investigations of Martian history

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.

    1976-01-01

    Geologic and stratigraphic analyses of Martian channels were accomplished using Mariner frames of high resolution. Crater counts were made to determine which forms had the least relative age. Results indicate that major channel and chaotic systems were relatively young, and that Mars experienced periods of enhanced erosive activity during a period of early dense atmospheric activity with rain. The problem of absolute age determination is discussed and geomorphological studies of selected Local Martian Regions are presented.

  4. Autonomous Martian flying rover

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A remotely programmable, autonomous flying rover is proposed to extensively survey the Martian surface environment. A Mach .3, solar powered, modified flying wing could cover roughly a 2000 mile range during Martian daylight hours. Multiple craft launched from an orbiting mother ship could provide near-global coverage. Each craft is envisioned to fly at about 1 km above the surface and measure atmospheric composition, pressure and temperature, map surface topography, and remotely penetrate the near subsurface looking for water (ice) and perhaps evidence of life. Data collected are relayed to Earth via the orbiting mother ship. Near surface guidance and control capability is an adaptation of current cruise missile technology. A solar powered aircraft designed to fly in the low temperature, low density, carbon dioxide Martian atmosphere near the surface appears feasible.

  5. Martian Environment Electrostatic Precipitator

    NASA Technical Reports Server (NTRS)

    McDougall, Michael Owen

    2016-01-01

    As part of the planned manned mission to Mars, NASA has noticed that shipping oxygen as a part of life support to keep the astronauts alive continuously is overly expensive, and impractical. As such, noting that the Martian atmosphere is 95.37% CO2, NASA chemists noted that one could obtain oxygen from the Martian atmosphere. The plan, as part of a larger ISRU (in-situ resource utilization) initiative, would extract water from the regolith, or the Martian soil which can be electrolyzed by solar panel produced voltage into hydrogen and oxygen. The hydrogen can then be used in the Sabatier reaction with carbon dioxide to produce methane and water producing a net reaction that does not lose water and outputs methane and oxygen for use as rocket fuel and breathing.

  6. Martian Meteorite Ages and Implications for Martian Cratering History

    NASA Technical Reports Server (NTRS)

    Nyquist, Laurence E.

    2006-01-01

    New radiometrically determined ages of Martian meteorites add to the growing number with crystallization ages < 1.4 Ga. The observation of mainly geologically young ages for the Martian meteorites, the only exception being the 4.5 Ga ALH84001 [1], is paradoxical when viewed in context of a Martian surface thought to be mostly much older as inferred from the surface density of meteorite craters [2]. There appears to be at least a twofold difference between the observed ages of Martian meteorites and their expected ages as inferred from the ages of Martian surfaces obtained from crater densities.

  7. The Martian Surface

    NASA Astrophysics Data System (ADS)

    Bell, Jim

    2008-06-01

    Dedication; Acknowledgements; Foreword; Part I. Introduction and Historical Perspective: 1. Exploration of the Martian surface: 1992-2007; 2. Historical context: the pre-MGS view of Mars' surface composition; Part II. Elemental Composition: Orbital and In Situ Surface Measurements: Part II. A. Results and Interpretations from New In Situ APXS Measurements: 3. Martian surface chemistry: APXS results from the Pathfinder landing site; 4. Mars exploration rovers - chemical composition by the APXS; Part II. B. Results and Interpretations from New Orbital Elemental Measurements: 5. Elemental abundances determined via the Mars Odyssey GRS; 6. Volatiles on Mars: scientific results from the Mars Odyssey Neutron Spectrometer; Part III. Mineralogy and Remote Sensing of Rocks, Soil, Dust, and Ices: Part III. A. Visible to Near-IR Telescopic and Orbital Measurements: 7. Mineralogy of the Martian surface from Mars Express OMEGA Observations; 8. Visible to near-IR multispectral orbital observations; Part III. B. Mid-IR and Magnetic Orbital Measurements: 9. Global mineralogy mapped from the Mars Global Surveyor Thermal Emission Spectrometer; 10. The compositional diversity and physical properties mapped from the Mars Odyssey Thermal Emission Imaging System; 11. Mars' crustal magnetization: a window into the past; Part III. C. Observations from Surface Landers/Rovers: 12. Multispectral imaging from Mars Pathfinder; 13. Mars Exploration Rover Pancam multispectral imaging of rocks, soil, and dust at Gusev Crater and Meridiani Planum ; 14. The mineralogy of Gusev Crater and Meridiani Planum derived from the Miniature Thermal Emission Spectrometers on the Spirit and Opportunity Rovers; 15. Iron mineralogy and aqueous alteration on Mars from the MER Mössbauer Spectrometers; 16. Magnetic properties results from surface landers and rovers; Part III. D: 17. Martian meteorites as crustal samples; Part IV. Physical Properties of Surface Materials: 18. The thermal inertia of the surface of

  8. Martian Surface Beneath Phoenix

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an image of the Martian surface beneath NASA's Phoenix Mars Lander. The image was taken by Phoenix's Robotic Arm Camera (RAC) on the eighth Martian day of the mission, or Sol 8 (June 2, 2008). The light feature in the middle of the image below the leg is informally called 'Holy Cow.' The dust, shown in the dark foreground, has been blown off of 'Holy Cow' by Phoenix's thruster engines.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  9. Timeline of Martian Volcanism

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.

    2011-05-01

    A recent study of Martian volcanism presents a timeline of the last major eruptions from 20 large volcanoes, based on the relative ages of caldera surfaces determined by crater counting. Stuart Robbins, Gaetano Di Achille, and Brian Hynek (University of Colorado) counted craters on high-resolution images from the the Context Camera (CTX) on Mars Reconnaissance Orbiter to date individual calderas, or terraces within calderas, on the 20 major Martian volcanoes. Based on their timeline and mapping, rates and durations of eruptions and transitions from explosive to effusive activity varied from volcano to volcano. The work confirms previous findings by others that volcanism was continuous throughout Martian geologic history until about one to two hundred million years ago, the final volcanic events were not synchronous across the planet, and the latest large-scale caldera activity ended about 150 million years ago in the Tharsis province. This timing correlates well with the crystallization ages (~165-170 million years) determined for the youngest basaltic Martian meteorites.

  10. Martian Meteor Ionization Layers

    NASA Technical Reports Server (NTRS)

    Grebowsky, J. M.; Pesnell, W. D.

    1999-01-01

    Small interplanetary grains bombard Mars, like all the solar system planets, and, like all the planets with atmospheres, meteoric ion and atom layers form in the upper atmosphere. We have developed a comprehensive one-dimensional model of the Martian meteoric ionization layer including a full chemical scheme. A persistent layer of magnesium ions should exist around an altitude of 70 km. Unlike the terrestrial case, where the metallic ions are formed via charge-exchange with the ambient ions, Mg(+) in the Martian atmosphere is produced by photoionization. Nevertheless, the predicted metal layer peak densities for Earth and Mars are similar. Diffusion solutions, such as those presented here, should be a good approximation of the metallic ions in regions where the magnetic field is negligible and may provide a significant contribution to the nightside ionosphere. The low ultraviolet absorption of the Martian atmosphere may make Mars an excellent laboratory in which to study meteoric ablation. Resonance lines not seen in the spectra of terrestrial meteors may be visible to a surface observatory in the Martian highlands.

  11. Isotopic age of the Black Forest Bed, Petrified Forest Member, Chinle Formation, Arizona: An example of dating a continental sandstone

    USGS Publications Warehouse

    Riggs, N.R.; Ash, S.R.; Barth, A.P.; Gehrels, G.E.; Wooden, J.L.

    2003-01-01

    Zircons from the Black Forest Bed, Petrified Forest Member, Chinle Formation, in Petrified Forest National Park, yield ages that range from Late Triassic to Late Archean. Grains were analyzed by multigrain TIMS (thermal-ionization mass spectrometry), single-crystal TIMS, and SHRIMP (sensitive, high-resolution ion-microprobe). Multiple-grain analysis yielded a discordia trajectory with a lower intercept of 207 ?? 2 Ma, which because of the nature of multiple-grain sampling of a detrital bed, is not considered conclusive. Analysis of 29 detrital-zircon grains by TIMS yielded U-PB ages of 2706 ?? 6 Ma to 206 ?? 6 Ma. Eleven of these ages lie between 211 and 216 ?? 6.8 Ma. Our statistical analysis of these grains indicates that the mean of the ages, 213 ?? 1.7 Ma, reflects more analytical error than geologic variability in sources of the grains. Grains with ages of ca. 1400 Ma were derived from the widespread plutons of that age exposed throughout the southwestern Cordillera and central United States. Twelve grains analyzed by SHRIMP provide 206Pb*/238U ages from 214 ?? 2 Ma to 200 ?? 4 Ma. We use these data to infer that cores of inherited material were present in many zircons and that single-crystal analysis provides an accurate estimation of the age of the bed. We further propose that, even if some degree of reworking has occurred, the very strong concentration of ages at ca. 213 Ma provides a maximum age for the Black Forest Bed of 213 ?? 1.7 Ma. The actual age of the bed may be closer to 209 Ma. Dating continental successions is very difficult when distinct ash beds are not clearly identified, as is the case in the Chinle Formation. Detrital zircons in the Black Forest Bed, however, are dominated by an acicular morphology with preserved delicate terminations. The shape of these crystals and their inferred environment of deposition in slow-water settings suggest that the crystals were not far removed from their site of deposition in space and likely not far in time

  12. A combined polarizing microscope, XRD, SEM, and specific gravity study of the petrified woods of volcanic origin from the Çamlıdere-Çeltikçi-Güdül fossil forest, in Ankara, Turkey

    NASA Astrophysics Data System (ADS)

    Hatipoğlu, Murat; Türk, Necdet

    2009-03-01

    The fossil forest in the Çamlıdere-Çeltikçi-Güdül region of the province of Ankara in Turkey has a large number of petrified coniferous and oak tree remains. Petrification occurred in volcanic ashes and tuffs with permineralization, and Fe, Mg, Ca and Ni ions played important roles in the substitution of Si for C. However, the petrified wood samples are heterogeneous in colouration, weight, toughness, and durability, despite being obtained from the same source. Those features are very important for end-users because petrified woods, if cut and polished, are used widely as both decorative indoor tiles and gemstone objects, but heterogeneous materials suffer large wastage while they are being worked and used. Chemical analyses, specific gravity measurements, polarizing microscope studies, X-ray diffraction patterns, and scanning electron image evaluations were performed to classify and identify the homogenous material of the petrified woods relating to its physical and mineralogical characteristics. The different characteristics of the petrified wood samples are due to their varying inner structures, which depend on the replacement silica-building phases and their ratios, and silica particle sizes. Thin sections and XRD patterns revealed that petrified woods in the region were silicified by replacement with both chalcedonic quartz components, including chalcedony (length-fast quartz), moganite and orthorhombic-silica (length-slow quartz), and opalline quartz components including opal-CT and opal-C (length-slow quartz). The scanning electron microscope images were shown that the internal structures of the petrified woods consist of mostly submicron-sized (100-800 nm), and partially nano-sized (60-120 nm) silica-building particles. So, the petrified wood samples can be firstly classified into five main-groups based on their colourations and specific gravity values, then, into three sub-groups based on the principal chalcedonic and opalline quartz silica

  13. Revised Lithostratigraphy of the Sonsela Member (Chinle Formation, Upper Triassic) in the Southern Part of Petrified Forest National Park, Arizona

    PubMed Central

    Martz, Jeffrey W.; Parker, William G.

    2010-01-01

    Background Recent revisions to the Sonsela Member of the Chinle Formation in Petrified Forest National Park have presented a three-part lithostratigraphic model based on unconventional correlations of sandstone beds. As a vertebrate faunal transition is recorded within this stratigraphic interval, these correlations, and the purported existence of a depositional hiatus (the Tr-4 unconformity) at about the same level, must be carefully re-examined. Methodology/Principal Findings Our investigations demonstrate the neglected necessity of walking out contacts and mapping when constructing lithostratigraphic models, and providing UTM coordinates and labeled photographs for all measured sections. We correct correlation errors within the Sonsela Member, demonstrate that there are multiple Flattops One sandstones, all of which are higher than the traditional Sonsela sandstone bed, that the Sonsela sandstone bed and Rainbow Forest Bed are equivalent, that the Rainbow Forest Bed is higher than the sandstones at the base of Blue Mesa and Agate Mesa, that strata formerly assigned to the Jim Camp Wash beds occur at two stratigraphic levels, and that there are multiple persistent silcrete horizons within the Sonsela Member. Conclusions/Significance We present a revised five-part model for the Sonsela Member. The units from lowest to highest are: the Camp Butte beds, Lot's Wife beds, Jasper Forest bed (the Sonsela sandstone)/Rainbow Forest Bed, Jim Camp Wash beds, and Martha's Butte beds (including the Flattops One sandstones). Although there are numerous degradational/aggradational cycles within the Chinle Formation, a single unconformable horizon within or at the base of the Sonsela Member that can be traced across the entire western United States (the “Tr-4 unconformity”) probably does not exist. The shift from relatively humid and poorly-drained to arid and well-drained climatic conditions began during deposition of the Sonsela Member (low in the Jim Camp Wash beds), well

  14. Radiometric Ages of Martian Meteorites compared to Martian Surfaces Ages

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Shih, C.-Y.

    1999-01-01

    The surprisingly young Rb-Sr age of the Shergotty meteorite contributed to early suggestions that it might be of martian origin. their redox state and oxygen isotopic compositions linked the shergottites to the clino-pyroxenite nakhlites and the dunite Chassigny, causing them to be grouped as SNC meteorites. These characteristics, but especially the similarity of the elemental and isotopic compositions of gases trapped in shergottites to those of the martian atmosphere, have caused the martian origin of the SNC and related meteorites to be widely accepted. Although the young ages were one of the early hints of a martian origin for the SNC meteorites, their interpretation has remained somewhat ambiguous. We will review the radiometric ages of the martian meteorites and attempt to place them into the context of martian surface ages.

  15. A Martian acoustic anemometer.

    PubMed

    Banfield, Don; Schindel, David W; Tarr, Steve; Dissly, Richard W

    2016-08-01

    An acoustic anemometer for use on Mars has been developed. To understand the processes that control the interaction between surface and atmosphere on Mars, not only the mean winds, but also the turbulent boundary layer, the fluxes of momentum, heat and molecular constituents between surface and atmosphere must be measured. Terrestrially this is done with acoustic anemometers, but the low density atmosphere on Mars makes it challenging to adapt such an instrument for use on Mars. This has been achieved using capacitive transducers and pulse compression, and was successfully demonstrated on a stratospheric balloon (simulating the Martian environment) and in a dedicated Mars Wind Tunnel facility. This instrument achieves a measurement accuracy of ∼5 cm/s with an update rate of >20 Hz under Martian conditions. PMID:27586767

  16. Martian polar geological studies

    NASA Technical Reports Server (NTRS)

    Cutts, J. A. J.

    1977-01-01

    Multiple arcs of rugged mountains and adjacent plains on the surface of Mars were examined. These features, located in the southern polar region were photographed by Mariner 9. Comparisons are made with characteristics of a lunar basin and mare; Mare imbrium in particular. The martian feature is interpreted to have originated in the same way as its lunar analog- by volcanic flooding of a large impact basin. Key data and methodology leading to this conclusion are cited.

  17. Age of Martian channels

    NASA Technical Reports Server (NTRS)

    Malin, M. C.

    1976-01-01

    The ages of large Martian channels have been studied by determining the relative abundances of craters superimposed on channels and adjacent terrains and by examining superposition relationships between channels and plains and mantle materials. The channels are extremely old, are spatially confined and temporally related to the ancient cratered terrain, and in many cases are related to the as yet poorly understood genetic processes of fretting and chaos formation. No evidence is found for recent channel activity.

  18. The martian surface.

    PubMed

    Opik, E J

    1966-07-15

    With the scarcity of factual data and the difficulty of applying crucial tests, many of the properties of the Martian surface remain a mystery; the planet may become a source of great surprises in the future. In the following, the conclusions are enumerated more or less in the order of their reliability, the more certain ones first, conjectures or ambiguous interpretations coming last. Even if they prove to be wrong, they may serve as a stimulus for further investigation. Impact craters on Mars, from collisions with nearby asteroids and other stray bodies, were predicted 16 years ago (5-7) and are now verified by the Mariner IV pictures. The kink in the frequency curve of Martian crater diameters indicates that those larger than 20 kilometers could have survived aeolian erosion since the "beginning." They indicate an erosion rate 30 times slower than that in terrestrial deserts and 70 times faster than micrometeorite erosion on the moon. The observed number, per unit area, of Martian craters larger than 20 kilometers exceeds 4 times that calculated from the statistical theory of interplanetary collisions with the present population of stray bodies and for a time interval of 4500 million years, even when allowance is made for the depletion of the Martian group of asteroids, which were more numerous in the past. This, and the low eroded rims of the Martian craters suggest that many of the craters have survived almost since the formation of the crust. Therefore, Mars could not have possessed a dense atmosphere for any length of time. If there was abundant water for the first 100 million years or so, before it escaped it could have occurred only in the solid state as ice and snow, with but traces of vapor in the atmosphere, on account of the low temperature caused by the high reflectivity of clouds and snow. For Martian life there is thus the dilemma: with water, it is too cold; without, too dry. The crater density on Mars, though twice that in lunar maria, is much

  19. The middle Martian atmosphere

    SciTech Connect

    Jaquin, R.F.

    1989-01-01

    Profiles of scattered light above the planetary limb from 116 Viking Orbiter images are used to constrain the temporal and spatial behavior of aerosols suspended in the Martian atmosphere. The data cover a wide range of seasons, locations, and viewing geometry, providing information about the aerosol optical properties and vertical distribution. The typical atmospheric column contains one or more discrete, optically thin, ice-like haze layers between 30 and 90 km elevation whose composition is inferred to be water ice. Below the detached hazes, a continuous haze, interpreted to have a large dust component, extends from as much as 50 km to the surface. The haze distribution exhibits an annual variation that reflects a seasonally driven circulation in the middle atmosphere. The potential role of stationary gravity waves in modifying the middle atmosphere circulation is explored using a linear theory applied to a realistic Martian environment. Martian topography derived from radar observations is decomposed into Fourier harmonics and used to linearly superpose gravity waves arising from each component. The larger amplitude topography on Mars combined with the absence of extended regions of smooth topography like oceans generates larger wave amplitudes than on the Earth. The circulation of the middle atmosphere is examined using a two-dimensional, linearized, axisymmetric model successfully employed in the study of the terrestrial mesosphere. Illustrations of temperature and wind speeds are presented for the southern summer solstice and southern spring equinox.

  20. The Martian magnetic field

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1979-01-01

    The paper presents an overview of the Martian magnetic field measurements and the criticisms made of them. The measurements of the Mars 2, 3, and 5 spacecraft were interpreted by Dolginov et al. (1976, 1978) to be consistent with an intrinsic planetary magnetic moment of 2.5 times 10 to the 22nd power gauss cu cm, basing this result on the apparent size of the obstacle responsible for deflecting the solar wind and an apparent encounter of the spacecraft with the planetary field. It is shown that if the dependence of the Martian magnetic moment on the rotation rate was linear, the estimate of the moment would be far larger than reported by Dolginov et al. An upper limit of 250 km is calculated for the dynamo radius using the similarity law, compared with 500 km obtained by Dolginov et al. It is concluded that the possible strength of a Martian dynamo is below expectations, and it is likely that the Mars dynamo is not presently operative.

  1. MARTIAN COLORS PROVIDE CLUES ABOUT MARTIAN WATER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA Hubble Space Telescope images of Mars taken in visible and infrared light detail a rich geologic history and provide further evidence for water-bearing minerals on the planet's surface. LEFT This 'true-color' image of Mars shows the planet as it would look to human eyes. It is clearly more earth-toned than usually depicted in other astronomical images, including earlier Hubble pictures. The slightly bluer shade along the edges of the disk is due to atmospheric hazes and wispy water ice clouds (like cirrus clouds) in the early morning and late evening Martian sky. The yellowish-pink color of the northern polar cap indicates the presence of small iron-bearing dust particles. These particles are covering or are suspended in the air above the blue-white water ice and carbon dioxide ice, which make up the polar cap. Accurate colors are needed to determine the composition and mineralogy of Mars. This can tell how water has influenced the formation of rocks and minerals found on Mars today, as well as the distribution and abundance of ice and subsurface liquid water. Confirmation of the presence of certain oxidized (rusted) minerals (processed by heat or water action) would imply the possibility of different, perhaps much more Earth-like, past Martian climate periods. Because the smallest features visible in this image are only about 14 miles (22 km) across, Hubble can track small-scale variations in the distribution of minerals that do not follow global trends. The image was generated from three separate Wide Field and Planetary Camera 2 images acquired at wavelengths of 410, 502, and 673 nanometers, in March 1997. RIGHT A false-color picture taken in infrared light reveals features that cannot be seen in visible light. Hubble's unique infrared view pinpoints variations in the abundance and distribution of unknown water-bearing minerals on the planet. While it has been known for decades that small amounts of water-bearing minerals exist on the planet's surface, the

  2. Martian Colors Provide Clues About Martian Water

    NASA Technical Reports Server (NTRS)

    1999-01-01

    NASA Hubble Space Telescope images of Mars taken in visible and infrared light detail a rich geologic history and provide further evidence for water-bearing minerals on the planet's surface.

    LEFT

    This 'true-color' image of Mars shows the planet as it would look to human eyes. It is clearly more Earth-toned than usually depicted in other astronomical images, including earlier Hubble pictures. The slightly bluer shade along the edges of the disk is due to atmospheric hazes and wispy water ice clouds (like cirrus clouds) in the early morning and late evening Martian sky. The yellowish-pink color of the northern polar cap indicates the presence of small iron-bearing dust particles. These particles are covering or are suspended in the air above the blue-white water ice and carbon dioxide ice, which make up the polar cap.

    Accurate colors are needed to determine the composition and mineralogy of Mars. This can tell how water has influenced the formation of rocks and minerals found on Mars today, as well as the distribution and abundance of ice and subsurface liquid water. Confirmation of the presence of certain oxidized (rusted) minerals (processed by heat or water action) would imply the possibility of different, perhaps much more Earth-like, past Martian climate periods. Because the smallest features visible in this image are only about 14 miles (22 km) across, Hubble can track small-scale variations in the distribution of minerals that do not follow global trends. The image was generated from three separate Wide Field and Planetary Camera 2 images acquired at wavelengths of 410, 502, and 673 nanometers, in March 1997.

    RIGHT

    A false-color picture taken in infrared light reveals features that cannot be seen in visible light. Hubble's unique infrared view pinpoints variations in the abundance and distribution of unknown water-bearing minerals on the planet. While it has been known for decades that small amounts of water-bearing minerals exist on the planet

  3. Chlorine Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  4. Exploring for Martian Life

    NASA Technical Reports Server (NTRS)

    Farmer, Jack D.; Chang, Sherwood (Technical Monitor)

    1997-01-01

    Terrestrial life appears to have arisen very quickly during late accretion, sometime between approximately 3.5 and 4.2 Ga. During this same time, liquid water appears to have been abundant at the surface of Mars and it is quite plausable that life originated there as well. We now believe that the last common ancestor of terrestrial life was a sulfur-metabolizing microbe that lived at high temperatures. Rooting of the RNA tree in thermophily probably reflects high temperature "bottle-necking" of the biosphere by giant impacts during late accretion, sometime after life had originated. If high temperature bottle-necking is a general property of early biosphere development, Martian life may have also developed in close association with hydrothermal systems. Several independent lines of evidence suggest that hydrothermal processes have played an important role during the geological history of Mars. Because hydrothermal deposits on Earth are known to capture and retain abundant microbial fossil information, they are considered prime targets in the search for an ancient Martian biosphere. An important step in planning for future landed missions to Mars is the selection of priority targets for high resolution orbital mapping. Geotectonic terranes on Mars that provide a present focus for ongoing site selection studies include channels located along the margins of impact crater melt sheets, or on the slopes of ancient Martian volcanoes, chaotic and fretted terranes where shallow subsurface heat sources are thought to have interacted with ground ice, and the floors of calderas and rifted basins. Orbital missions in 1996, 1998 and 2001 will provide opportunities for high resolution geological mapping at key sites in such terranes, as a basis for selecting targets for future landed missions for exopaleontology.

  5. Spectra of Martian Andesitic Materials

    NASA Technical Reports Server (NTRS)

    Minitti, M. E.; Rutherford, M. J.; Weitz, C. M.

    2001-01-01

    The Mars Pathfinder and Mars Global Surveyor missions both detected andesitic compositions on the martian surface. We have investigated the spectral properties of unoxidized and oxidized martian andesitic samples crystallized with and without water. Additional information is contained in the original extended abstract.

  6. Planimetric Martian triangulations

    USGS Publications Warehouse

    Arthur, D.W.G.; McMacken, D.K.

    1977-01-01

    Narrow-angle photographs, which have severe drawbacks for stereophotogrammetry, have advantages for simple plane triangulations. Rectified narrow-angle pictures corrected for map projection effects can be combined in the map plane in relatively accurate planimetric triangulations. Provided the strict precepts of least squares are not followed, these triangulations can incorporate considerable overdetermination without increase in the labor of solving the equations. These plane triangulations have been used successfully in the cartography of Mars and are illustrated here by a triangulation of the environs of the prime Martian landing site.

  7. The New Martians

    NASA Astrophysics Data System (ADS)

    Kanas, Nick

    In The New Martians,the crewmembers undergo a great deal of psychological and interpersonal stress during their return home, in part prompted by the actions of a mysterious presence on board. Of course, no one knows for sure if such a presence will actually materialize during a real Mars expedition! But psychosocial issues will nevertheless affect a Mars crew due to the isolation, confinement, and long separation from family and friends that will characterize such a mission. In what follows, many of these issues will be reviewed, followed in each section by illustrations from the novel.

  8. Polygons in Martian Frost

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-428, 21 July 2003

    This June 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a polygonal pattern developed in seasonal carbon dioxide frost in the martian southern hemisphere. The frost accumulated during the recent southern winter; it is now spring, and the carbon dioxide frost is subliming away. This image is located near 80.4oS, 200.2oW; it is illuminated by sunlight from the upper left, and covers an area 3 km (1.9 mi) across.

  9. Rocky Martian Plain

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The rocky Martian plain surrounding Viking 2 is seen in high resolution in this 85-degree panorama sweeping from north at the left to east at right during the Martian afternoon on September 5. Large blocks litter the surface. Some are porous, sponge-like rocks like the one at the left edge (size estimate: 1 1/2 to 2 feet); others are dense and fine-grained, such as the very bright rounded block (1 to 1 1/2 feet across) toward lower right. Pebbled surface between the rocks is covered in places by small drifts of very fine material similar to drifts seen at the Viking 1 landing site some 4600 miles to the southwest. The fine-grained material is banked up behind some rocks, but wind tails seen by Viking 1 are not well-developed here. On the right horizon, flat-topped ridges or hills are illuminated by the afternoon sun. Slope of the horizon is due to the 8-degree tilt of the spacecraft.

  10. Martian soil color variations

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Rocks and soils on the surface are thought to be composed of minerals similar to those found on Earth's surface. One of the most important tools for recognizing these minerals is the spectrum of sunlight reflected by them. At the visible and near-infrared light wavelengths measured by the Imager for Mars Pathfinder (IMP), the most important coloring materials in the Martian surface are iron minerals. There are two broad classes of iron minerals. Minerals which occur in igneous rocks (such as pyroxene) have a relatively flat spectrum and they reflect only a small amount of light; they are said to have a low reflectance. Ferric iron minerals, which occur as weathering products, reflect longer-wavelength light and absorb short-wavelength light, hence their very red color. The relative brightnesses of Martian surface materials in IMP's different wavelength filter is a powerful tool for recognizing the iron minerals present.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  11. Guadua zuloagae sp. nov., the First Petrified Bamboo Culm Record from the Ituzaingó Formation (Pliocene), Paraná Basin, Argentina

    PubMed Central

    Brea, Mariana; Zucol, Alejandro F.

    2007-01-01

    Background and Aims The anatomical characterization and morphology of Guadua zuloagae nov. sp. (Poaceae–Bambusoideae) culm was determined. This material was collected at the Toma Vieja fossil locality, Paraná basin, Argentina. This fossil culm is the first record of Bambusoideae in sediments of the Pliocene from the Ituzaingó Formation. The studied specimen was compared with the taxa of the Bambusoideae sub-family, especially with the American woody bamboos and others taxa that have woody culms, including Arundo, Thysalonaena and Gynerium. Methods The material was preserved by siliceous cellular permineralization, and it was prepared for microscopic examination by surface polishing and thin sections. The morphology and anatomy of this new species were described. The estimated height, critical buckling height and safety factor were calculated on the basis of the fossil bamboo diameter using the formula of Niklas. The relationship and comparison with the nearest living relatives (NLRs) are discussed. Key Results Well-preserved petrified culm with internodes and nodes from the Pliocene of Argentina provides the basis for the description of a new fossil bamboo, Guadua zuloagae. The results of the anatomical analysis of the fossil bamboo showed a great affinity with the extant species Guadua angustifolia and constitute the first evidence of petrified bamboo culm. Conclusions The new fossil bamboo culm constitutes the only fossil record, preserved as permineralized by silicification, in the world. This fossil record indicates that the genus Guadua was more widespread in the past than today. Discovery of G. zuloagae allows the presence of a Bambusoideae understorey in the mixed forests described for the Ituzaingó Formation to be inferred. The climatic conditions inferred from fossil bamboo and sedimentary deposits indicate a temperate-warm, humid climate. PMID:17728337

  12. Ancient oceans and Martian paleohydrology

    NASA Technical Reports Server (NTRS)

    Baker, Victor R.; Strom, Robert G.; Gulick, Virginia C.; Kargel, Jeffrey S.; Komatsu, Goro; Kale, Vishwas S.

    1991-01-01

    The global model of ocean formation on Mars is discussed. The studies of impact crater densities on certain Martian landforms show that late in Martian history there could have been coincident formation of: (1) glacial features in the Southern Hemisphere; (2) ponded water and related ice features in the northern plains; (3) fluvial runoff on Martian uplands; and (4) active ice-related mass-movement. This model of transient ocean formation ties these diverse observations together in a long-term cyclic scheme of global planetary operation.

  13. Isotopic Evidence for a Martian Regolith Component in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Nyquist, L. E.; Bogard, D. D.; Garrison, D. H.; Sutton, S.

    2009-01-01

    Noble gas measurements in gas-rich impact-melt (GRIM) glasses in EET79001 shergottite showed that their elemental and isotopic composition is similar to that of the Martian atmosphere [1-3]. The GRIM glasses contain large amounts of Martian atmospheric gases. Those measurements further suggested that the Kr isotopic composition of Martian atmosphere is approximately similar to that of solar Kr. The (80)Kr(sub n) - (80)Kr(sub M) mixing ratio in the Martian atmosphere reported here is approximately 3%. These neutron-capture reactions presumably occurred in the glass-precursor regolith materials containing Sm- and Br- bearing mineral phases near the EET79001/ Shergotty sites on Mars. The irradiated materials were mobilized into host rock voids either during shock-melting or possibly by earlier aeolian / fluvial activity.

  14. Trajectories of Martian Habitability

    PubMed Central

    2014-01-01

    Abstract Beginning from two plausible starting points—an uninhabited or inhabited Mars—this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments. Key Words: Mars—Habitability—Liquid water—Planetary science. Astrobiology 14, 182–203. PMID:24506485

  15. Martian City Map

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 May 2004 Seasonal frost can enhance the view from orbit of polar polygonal patterns on the surface of Mars. Sometimes these patterns look something like a city map, or the view from above a city lit-up at night. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example from the south polar region near 80.7oS, 70.6oW. Polar polygons on Mars are generally believed, though not proven, to be the result of freeze/thaw cycles of ice occurring within the upper few meters (several yards) of the martian subsurface. The image shown here covers an area about 3 km (1.9 mi) across; sunlight illuminates the scene from the upper left.

  16. Martian Ice Caves

    NASA Astrophysics Data System (ADS)

    Frederick, R. D.; Billings, T. L.; McGown, R. D.; Walden, B. E.

    2000-07-01

    Ice in Martian lava tube caves would have scientific and developmental value. These natural channels in rock may hold keys to Mars' past as well as potential resources for humanity's futures. Terrestrial lava tube caves are natural receptacles for accumulations of water. Often, due to lower temperatures coupled with the superior insulation properties of the surrounding rock, these accumulations are in the form of ice. Historically, ice was mined from some lava tube caves. Many of the lava tubes in the Central Oregon area sport such names as "Arnolds Ice Cave," "Surveyors Ice Cave," "South Ice Cave," etc. These caves are not caves in ice, but rather common lava tubes with seasonal, and sometimes perennial ice deposits. Locating and cataloging similar features on Mars, could be of value for the colonization of Mars and the search for life. Such features may also prove useful in helping to determine past climatic conditions on the Red Planet.

  17. Trajectories of martian habitability.

    PubMed

    Cockell, Charles S

    2014-02-01

    Beginning from two plausible starting points-an uninhabited or inhabited Mars-this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments.

  18. Martian surface weathering studies

    NASA Technical Reports Server (NTRS)

    Calvin, M.

    1973-01-01

    The nature of the Martian surface was characterized by means of its reflectance properties. The Mariner 9 photography was used to establish terrain units which were crossed by the Mariner 6 and 7 paths. The IR reflectance measured by the IR spectrometers on these spacecraft was to be used to indicate the nature of the surface within these units. There is an indication of physical size and/or compositional variation between units but too many natural parameters can vary (size, shape, composition, adsorbed phases, reradiation, atmospheric absorbtion, temperature gradients, etc.) to be certain what effect is causing those variations observed. It is suggested that the characterization could be fruitfully pursued by a group which was dedicated to peeling back the layers of minutia affecting IR reflectance.

  19. Martian Meteorological Lander

    NASA Astrophysics Data System (ADS)

    Vorontsov, V.; Pichkhadze, K.; Polyakov, A.

    2002-01-01

    Martian meteorological lander (MML) is dedicated for landing onto the Mars surface with the purpose to carry on the monitoring of Mars atmosphere condition at a landing point during one Martian year. MML is supposed to become the basic element of a global net of meteorological mini stations and will permit to observe the dynamics of Martian atmosphere parameters changes during a long time duration. The main scientific tasks of MML are as follows: -study of vertical structure of Mars atmosphere during MML descending; -meteorological observations on Mars surface during one Martian year. One of the essential factor influencing to the lander design is descent trajectory design. During the preliminary phase of development five (5) options of MML were considered. In our opinion, these variants provide the accomplishment of the above-mentioned tasks with a high effectiveness. Joined into the first group, variants with parachute system and with Inflatable Air Brakes+Inflatable Airbag are similar in arranging of pre-landing braking stage and completely analogous in landing by means of airbags. The usage of additional Inflatable Braking Unit (IBU) in the second variant does not affect the procedure of braking - decreasing of velocity by the moment of touching the surface due to decreasing of ballistic parameter Px. A distinctive feature of MML development variants of other three concepts is the presence of Inflatable Braking Unit (IBU) in their configurations (IBU is rigidly joined with landing module up to the moment of its touching the surface). Besides, in variant with the tore-shaped IBU it acts as a shock- absorbing unit. In two options, Inflatable Braking Shock-Absorbing Unit (IBSAU) (or IBU) releases the surface module after its landing at the moment of IBSAU (or IBU) elastic recoil. Variants of this concept are equal in terms of mass (approximately 15 kg). For variants of concepts with IBU the landing velocity is up to50-70 m/s. Stations of last three options are

  20. Prospecting for Martian Ice

    NASA Technical Reports Server (NTRS)

    McBride, S. A.; Allen, C. C.; Bell, M. S.

    2005-01-01

    During high Martian obliquity, ice is stable to lower latitudes than predicted by models of present conditions and observed by the Gamma Ray Spectrometer (approx. 60 deg N). An ice-rich layer deposited at mid-latitudes could persist to the present day; ablation of the top 1 m of ice leaving a thin insulating cover could account for lack of its detection by GRS. The presence of an ice-layer in the mid-latitudes is suggested by a network of polygons, interpreted as ice-wedge cracks. This study focuses on an exceptional concentration of polygons in Western Utopia (section of Casius quadrangle, roughly 40 deg - 50 deg N, 255 deg - 300 deg W). We attempt to determine the thickness and age of this ice layer through crater-polygons relations.

  1. Trajectories of martian habitability.

    PubMed

    Cockell, Charles S

    2014-02-01

    Beginning from two plausible starting points-an uninhabited or inhabited Mars-this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments. PMID:24506485

  2. An Adulterated Martian Meteorite

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    1999-07-01

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

  3. No `nanofossils' in martian meteorite

    NASA Astrophysics Data System (ADS)

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

    1997-12-01

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

  4. Martian 'Kitchen Sponge'

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This picture is illuminated by sunlight from the upper left. It shows a tiny 1 kilometer by 1 kilometer (0.62 x 0.62 mile) area of the martian north polar residual ice cap as it appears in summertime.

    The surface looks somewhat like that of a kitchen sponge--it is flat on top and has many closely-spaced pits of no more than 2 meters (5.5 ft) depth. The upper, flat surface in this image has a medium-gray tone, while the pit interiors are darker gray. Each pit is generally 10 to 20 meters (33-66 feet) across. The pits probably form as water ice sublimes--going directly from solid to vapor--during the martian northern summer seasons. The pits probably develop over thousands of years. This texture is very different from what is seen in the south polar cap, where considerably larger and more circular depressions are found to resemble slices of swiss cheese rather than a kitchen sponge.

    This picture was taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during northern summer on March 8, 1999. It was one of the very last 'calibration' images taken before the start of the Mapping Phase of the MGS mission, and its goal was to determine whether the MOC was properly focused. The crisp appearance of the edges of the pits confirmed that the instrument was focused and ready for its 1-Mars Year mapping mission. The scene is located near 86.9oN, 207.5oW, and has a resolution of about 1.4 meters (4 ft, 7 in) per pixel.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  5. Martian surface simulations

    NASA Technical Reports Server (NTRS)

    Gaskell, R. W.

    1992-01-01

    Current scenarios for a Mars landing involve the extensive analysis of the surface near the landing site. Pinpoint landing, for example, requires a detailed mapping of the area from orbit for landmark identification and landing site selection, and the use by the lander of its own imaging data to recognize these landmarks and to guide itself safely to the surface. Hazard avoidance requires sufficient orbital imaging to ensure that safe landing sites exist, with the lander using its sensory data to find one of them. Once on the surface, a rover must be able to avoid or surmount obstacles, travel across surfaces with varying compositions and slopes, and navigate to a desired destination. Computer simulated Martian surfaces are being constructed to aid in the development of these exploration technologies. These surface simulations attempt to mimic the specific geologic episodes that built the surface, such as cratering, lava flows, and aeolian activity. Each episode takes a preexisting surface as a starting point, alters it in some way, and stores the new surface for further processing. This modular construction makes it possible for new processes to be included without altering existing software.

  6. Universal multifractal Martian topography

    NASA Astrophysics Data System (ADS)

    Landais, F.; Schmidt, F.; Lovejoy, S.

    2015-07-01

    In the present study, we investigate the scaling properties of the topography of Mars. Planetary topographic fields are well known to roughly exhibit (mono)fractal behavior. Indeed, the fractal formalism is reproduces much of the variability observed in topography. Still, a single fractal dimension is not enough to explain the huge variability and intermittency. Previous studies have claimed that fractal dimensions might be different from one region to an other, excluding a general description at the planetary scale. In this article, we are analyzing the Martian topographic data with a multifractal formalism to study the scaling intermittency. In the multifractal paradigm, the apparent local variation of the fractal dimension is interpreted as a statistical property of multifractal fields. We analyze the topography measured with the laser altimeter MOLA at 300 m horizontal resolution, 1 m vertical resolution. We adapted the Haar fluctuation method to the the irregularly sampled signal. The results suggest a multifractal behavior from planetary scale down to 10 km. From 10 km to 300 m, the topography seems to be simple monofractal. This transition indicates a significant change in the geological processes governing the Red Planet's surface.

  7. Universal multifractal Martian topography

    NASA Astrophysics Data System (ADS)

    Landais, F.; Schmidt, F.; Lovejoy, S.

    2015-11-01

    In the present study, we investigate the scaling properties of the topography of Mars. Planetary topographic fields are well known to roughly exhibit (mono)fractal behavior. Indeed, the fractal formalism reproduces much of the variability observed in topography. Still, a single fractal dimension is not enough to explain the huge variability and intermittency. Previous studies have claimed that fractal dimensions might be different from one region to another, excluding a general description at the planetary scale. In this article, we analyze the Martian topographic data with a multifractal formalism to study the scaling intermittency. In the multifractal paradigm, the apparent local variation of the fractal dimension is interpreted as a statistical property of multifractal fields. We analyze the topography measured with the Mars Orbiter Laser altimeter (MOLA) at 300 m horizontal resolution, 1 m vertical resolution. We adapted the Haar fluctuation method to the irregularly sampled signal. The results suggest a multifractal behavior from the planetary scale down to 10 km. From 10 to 300 m, the topography seems to be simple monofractal. This transition indicates a significant change in the geological processes governing the Red Planet's surface.

  8. A Violet Martian Sky

    NASA Technical Reports Server (NTRS)

    1997-01-01

    These clouds from Sol 15 have a new look. As water ice clouds cover the sky, the sky takes on a more bluish cast. This is because small particles (perhaps a tenth the size of the martian dust, or one-thousandth the thickness of a human hair) are bright in blue light, but almost invisible in red light. Thus, scientists expect that the ice particles in the clouds are very small. The clouds were imaged by the Imager for Mars Pathfinder (IMP).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  9. Martian terrain - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This area of terrain near the Sagan Memorial Station was taken on Sol 3 by the Imager for Mars Pathfinder (IMP). 3D glasses are necessary to identify surface detail.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  10. Melting in Martian Snowbanks

    NASA Technical Reports Server (NTRS)

    Zent, A. P.; Sutter, B.

    2005-01-01

    Precipitation as snow is an emerging paradigm for understanding water flow on Mars, which gracefully resolves many outstanding uncertainties in climatic and geomorphic interpretation. Snowfall does not require a powerful global greenhouse to effect global precipitation. It has long been assumed that global average temperatures greater than 273K are required to sustain liquid water at the surface via rainfall and runoff. Unfortunately, the best greenhouse models to date predict global mean surface temperatures early in Mars' history that differ little from today's, unless exceptional conditions are invoked. Snowfall however, can occur at temperatures less than 273K; all that is required is saturation of the atmosphere. At global temperatures lower than 273K, H2O would have been injected into the atmosphere by impacts and volcanic eruptions during the Noachian, and by obliquity-driven climate oscillations more recently. Snow cover can accumulate for a considerable period, and be available for melting during local spring and summer, unless sublimation rates are sufficient to remove the entire snowpack. We decided to explore the physics that controls the melting of snow in the high-latitude regions of Mars to understand the frequency and drainage of snowmelt in the high martian latitudes.

  11. The Martian surface layer

    NASA Technical Reports Server (NTRS)

    Christensen, Philip R.; Moore, Henry J.

    1992-01-01

    The global characteristics of the Martian surface layer are discussed on the basis of thermal, albedo, color, and radar data for the region between approximately 60 deg S and 60 deg N. Thermal data reveal the presence of large low- and high-inertia regions of the northern hemisphere, with much of the south covered by material of moderate inertia. There is a strong anticorrelation between inertia and albedo, a correlation between inertia and rock abundance, and, over much of the planet, a correlation of radar-derived density with inertia. Viking Orbiter color data indicate the presence of three major surface materials: low-inertia, bright-red material that is presumably dust; high-inertia, dark-grey material interpreted to be lithic material mixed with palagonitelike dust; and moderate-inertia, dark-red material that is rough at subpixel scales and interpreted to be indurated. Observations from the Viking landing sites show rocks, fines of varying cohesion and crusts. These sites have indications of aeolian erosion and deposition in the recent past.

  12. Salty Martian Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    These plots, or spectra, show that a rock dubbed 'McKittrick' near the Mars Exploration Rover Opportunity's landing site at Meridiani Planum, Mars, has higher concentrations of sulfur and bromine than a nearby patch of soil nicknamed 'Tarmac.' These data were taken by Opportunity's alpha particle X-ray spectrometer, which produces a spectrum, or fingerprint, of chemicals in martian rocks and soil. The instrument contains a radioisotope, curium-244, that bombards a designated area with alpha particles and X-rays, causing a cascade of reflective fluorescent X-rays. The energies of these fluorescent X-rays are unique to each atom in the periodic table, allowing scientists to determine a target's chemical composition.

    Both 'Tarmac' and 'McKittrick' are located within the small crater where Opportunity landed. The full spectra are expressed as X-ray intensity (logarithmic scale) versus energy. When comparing two spectra, the relative intensities at a given energy are proportional to the elemental concentrations, however these proportionality factors can be complex. To be precise, scientists extensively calibrate the instrument using well-analyzed geochemical standards.

    Both the alpha particle X-ray spectrometer and the rock abrasion tool are located on the rover's instrument deployment device, or arm.

  13. Martian Igneous Geochemistry: The Nature of the Martian Mantle

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, D. W.; Elkins-Tanton, L. T.; Peng, Z. X.; Herrin, J. S.

    2012-01-01

    Mafic igneous rocks probe the interiors of their parent objects, reflecting the compositions and mineralogies of their source regions, and the magmatic processes that engendered them. Incompatible trace element contents of mafic igneous rocks are widely used to constrain the petrologic evolution of planets. We focus on incompatible element ratios of martian meteorites to constrain the petrologic evolution of Mars in the context of magma ocean/cumulate overturn models [1]. Most martian meteorites contain some cumulus grains, but regardless, their incompatible element ratios are close to those of their parent magmas. Martian meteorites form two main petrologic/ age groupings; a 1.3 Ga group composed of clinopyroxenites (nakhlites) and dunites (chassignites), and a <1 Ga group composed of basalts and lherzolites (shergottites).

  14. Bacteria under simulated Martian conditions.

    PubMed

    Young, R S; Deal, P H; Bell, J; Allen, J L

    1964-01-01

    The behavior of organisms in simulated Martian conditions is of great importance to exobiology for two reasons: (1) Because of the extreme environment of Mars, the likelihood of contamination of the planet by earth organisms is considered slight by some scientists. To date, there has been little evidence to contradict this supposition. Such evidence is presented. (2) The selection and adaptation of earth bacteria to Martian conditions is potentially significant in understanding Martian life, if it exists, and may be helpful in designing life-detection techniques and devices. Of course, simulation attempts, based on current knowledge of the Mars environment, may be far from the actual conditions, and extrapolations made from such situations of no real significance. However, generalizations can be made and cautious interpretation of the results of those experiments seems well worth reporting. A new technique for simulation of known parameters of the Martian environment is discussed along with possible biological implications. The response of bacteria to such simulation is demonstrated in terms of survival and growth, showing that certain bacteria will not only survive, but grow during simulated Martian freeze-thaw cycling if water is present. Ways are demonstrated in which water can be present on Mars although not detectable with current technology. Plans for future experimentation are discussed.

  15. Water and processes of degradation in the Martian landscape.

    NASA Technical Reports Server (NTRS)

    Milton, D. J.

    1973-01-01

    Some large channels on Mars show features, notably bars and braiding, that indicate an origin by the action of running water. Smaller channels on steep slopes may have been produced by runoff of precipitation. Dendritic canyon systems suggest ground water sapping, which may have been an effective agent in cliff retreat generally. Extensive plains developed as cliffs retreated and, although modified by later wind action, may be regarded as relict landforms from a fluvial stage of Martian history.

  16. Depositional history of the Late Triassic Chinle fluvial system at the Petrified Forest National Park: U-Pb geochronology, regional correlation and insights into early dinosaur evolution

    NASA Astrophysics Data System (ADS)

    Ramezani, J.; Fastovsky, D. E.; Bowring, S. A.; Hoke, G. D.

    2010-12-01

    Understanding patterns of biotic evolution and climate change in deep time requires a reliable temporal framework. The Colorado Plateau contains a rich record of both, but is lacking in reliable age data. High-precision U-Pb geochronology has the power to resolve subtle differences among mixed populations of volcanic zircon contained in tuffaceous sedimentary rocks. We report maximum depositional ages for interbedded tuffaceous rocks collected within a highly refined stratigraphic context from the Late Triassic Chinle Formation as exposed in the Petrified Forest National Park, AZ, USA. The results provide unprecedented insights into the depositional history of the Chinle fluvial system, as well as key data on the biostratigraphy of Late Triassic land vertebrate faunas. Our geochronological results indicate that the Blue Mesa, Sonsela and Petrified Forest Members of Chinle Formation, with a cumulative thickness of ca. 293 meters, were deposited during a period in excess of 17 m.y. that spans nearly the entire Norian stage of the Late Triassic. The underlying Mesa Redondo Member may extend into Carnian and the overlying Owl Rock Member into Rhaetian. Different stratigraphic intervals within the section are characterized by drastically different average sediment accumulation rates; the highest rates are found in the Sonsela Member and most likely reflect missing time due to erosion associated with extensive channeling preserved in this unit. The new Chinle geochronology demonstrates that the common practice of basin-wide correlation of fluvial strata based on lithostratigraphic criteria is prone to serious errors. A mid-Norian age for the Adamanian to Revueltian land vertebrate faunachron boundary, as suggested by the revised Late Triassic timescale, is no longer compatible with the idea that the faunachron boundary is coincident with the Carnian-Norian Stage boundary. Our new temporal constraints for the Chinle along with limited available age data from the South

  17. Geologic mapping as a method for the construction of a detailed and testable lithostratigraphic model for the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona

    NASA Astrophysics Data System (ADS)

    Skinner, L. A.; Martz, J. W.; Parker, W.; Raucci, J.; Umhoefer, P. J.

    2010-12-01

    The Upper Triassic Chinle Formation in Petrified Forest National Park represents some of the most intensively studied Upper Triassic strata in western North America. Five stratigraphic members are exposed within the park, from oldest to youngest: the Mesa Redondo, Blue Mesa, Sonsela, Petrified Forest, and Owl Rock Members. Despite numerous stratigraphic studies of the Chinle Formation and two attempts at mapping the park over the past sixty years, sandstone marker beds in the Sonsela Member at the north and south ends of the park were still poorly mapped and correlated. Studies in the years 2002 and 2006 claimed that two sandstones which previous workers had considered to lie at different stratigraphic levels (the Jasper Forest Bed and the Flattops One sandstones in the Martha’s Butte beds) were actually correlative. This correlation resulted in a three-part division of the Sonsela Member and had a major impact on vertebrate biostratigraphy. In a recent attempt to resolve confusions regarding Chinle Formation lithostratigraphy and biostratigraphy, we have completely walked out lithologic contacts through most of the park. The resulting new geologic map, revised lithostratigraphic model, and associated data resolves the 2002 and 2006 miscorrelations by demonstrating that the Jasper Forest Bed capping Blue Mesa and Agate Mesa and Flattops One sandstones (Martha’s Butte beds) are stratigraphically distinct, resulting in a thicker and more complex five-part model for the Sonsela Member, and considerably modifying the vertebrate biostratigraphy. New geologic mapping also resulted in a detailed lithostratigraphic framework for the northern park which has previously been poorly understood, and several important new marker beds, including a purple-gray bed that represents the base of the Owl Rock Member. The revised geologic map is an ArcGIS product that includes an updated lithostratigraphic model for the Chinle Formation, fossil localities, and hyperlinks to labeled

  18. Martian 'Swiss Cheese'

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This image is illuminated by sunlight from the upper left.

    Looking like pieces of sliced and broken swiss cheese, the upper layer of the martian south polar residual cap has been eroded, leaving flat-topped mesas into which are set circular depressions such as those shown here. The circular features are depressions, not hills. The largest mesas here stand about 4 meters (13 feet) high and may be composed of frozen carbon dioxide and/or water. Nothing like this has ever been seen anywhere on Mars except within the south polar cap, leading to some speculation that these landforms may have something to do with the carbon dioxide thought to be frozen in the south polar region. On Earth, we know frozen carbon dioxide as 'dry ice'. On Mars, as this picture might be suggesting, there may be entire landforms larger than a small town and taller than 2 to 3 men and women that consist, in part, of dry ice.

    No one knows for certain whether frozen carbon dioxide has played a role in the creation of the 'swiss cheese' and other bizarre landforms seen in this picture. The picture covers an area 3 x 9 kilometers (1.9 x 5.6 miles) near 85.6oS, 74.4oW at a resolution of 7.3 meters (24 feet) per pixel. This picture was taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during early southern spring on August 3, 1999.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  19. Martian Alteration in Unique Meteorite NWA 8159?

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  20. The Enigmatic Martian Polar Caps

    SciTech Connect

    James, Philip

    2005-08-17

    The Martian polar caps have puzzled astronomers for over a century. Extensive study by many instruments on various spacecraft has resolved many questions but has at the same time created a new generation of puzzles. The polar caps are intimately coupled to the current Martian climate and volatile cycles. They also hold clues to climate variations on a variety of longer time scales. The results of recent missions will be reviewed, and the potential outlook for resolution of the outstanding questions will be examined.

  1. Catalog of Martian Materials

    NASA Astrophysics Data System (ADS)

    Newsom, Horton E.; Hagerty, J. J.

    1998-01-01

    biology experiments. The surface may also contain material delivered to the surface, including solar-wind He-3, and chondritic material from meteorites and cosmic dust. One of the biggest problems is the probable lack of water any where near the surface, except in the the form of ice near the poles. A list summarizing some of the familiar and unfamiliar materials that may be encountered on the martian surface is presented.

  2. Tales of A Martian Schoolmarm.

    ERIC Educational Resources Information Center

    Ascenzi, Laurie

    2000-01-01

    A former substitute teacher explains how she won first-graders' attention and significantly improved deportment by pretending to be a Martian with different communication modes and hearing capabilities than terrestrials. Children painlessly learn tips on listening, communicating, and engaging in friendly behaviors. (MLH)

  3. Spirit Begins Third Martian Year

    NASA Technical Reports Server (NTRS)

    2007-01-01

    As it finished its second Martian year on Mars, NASA's Mars Exploration Rover Spirit was beginning to examine a group of angular rocks given informal names corresponding to peaks in the Colorado Rockies. A Martian year the amount of time it takes Mars to complete one orbit around the sun lasts for 687 Earth days. Spirit completed its second Martian year on the rover's 1,338th Martian day, or sol, corresponding to Oct. 8, 2007.

    Two days later, on sol 1,340 (Oct. 10, 2007), Spirit used its front hazard-identification camera to capture this wide-angle view of its robotic arm extended to a rock informally named 'Humboldt Peak.' For the rocks at this site on the southern edge of the 'Home Plate' platform in the inner basin of the Columbia Hills inside Gusev Crater, the rover team decided to use names of Colorado peaks higher than 14,000 feet. The Colorado Rockies team of the National League is the connection to the baseball-theme nomenclature being used for features around Home Plate.

    The tool facing Spirit on the turret at the end of the robotic arm is the Moessbauer spectrometer.

  4. Curiosity analyzes Martian soil samples

    NASA Astrophysics Data System (ADS)

    Showstack, Randy; Balcerak, Ernie

    2012-12-01

    NASA's Mars Curiosity rover has conducted its first analysis of Martian soil samples using multiple instruments, the agency announced at a 3 December news briefing at the AGU Fall Meeting in San Francisco. "These results are an unprecedented look at the chemical diversity in the area," said NASA's Michael Meyer, program scientist for Curiosity.

  5. Silicate mineralogy of martian meteorites

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  6. Atmospheric maneuvering during Martian entry

    NASA Astrophysics Data System (ADS)

    Tauber, Michael E.; Bowles, Jeffrey V.; Yang, Lily

    A comparative-advantages study is made of two different Martian atmospheric entry maneuvers, on the basis of calculation results for the case of a vehicle with a maximum L/D ratio of 2.3. Entries from a highly elliptical Martian orbit at 5 km/sec are more difficult than those from a lower altitude and speed orbit at 3.5 km/sec, due to their more stringent guidance requirements. Efforts to reduce the deceleration for the higher speed entry by lift-modulation achieved a 40-percent reduction, but at the cost of a 50-percent decrease in lateral range. The lower-speed entry's gliding trajectory is noted to encounter a far more benign atmospheric environment.

  7. Water in the Martian regolith

    NASA Technical Reports Server (NTRS)

    Anderson, Duwayne M.

    1988-01-01

    The state of water in the Martian regolith is addressed. The water-ice phase composition, adsorption-desorption and evaporation phenomena, and brine compositions of six antarctic soils that are considered to be good terrestrial analogues of the Martian surface materials are examined. Experiments have shown that, for temperatures below freezing and relative humidities less than 100 percent, absorbed water and vapor are the only stable phases in the regolith. When the relative humidity reaches 100 percent, ice may form and coexist with the absorbed liquid phase. The absorbed water content declines with decreasing temperature; however, the presence of dissolved solutes can result in appreciable adsorbed liquid phase at temperatures as low as 210 K. Such properties may have a profound influence on martial geomorphology, physical and chemical weathering, and the exchange of water between the atmosphere and regolith.

  8. Dust Mitigation for Martian Exploration

    NASA Technical Reports Server (NTRS)

    Williams, Blakeley Shay

    2011-01-01

    One of the efforts of the In-Situ Resource Utilization project is to extract oxygen, fuel, and water from the Martian air. However, the surface of Mars is covered in a layer of dust, which is uploaded into the atmosphere by dust devils and dust storms. This atmospheric dust would be collected along with the air during the conversion process. Thus, it is essential to extract the dust from the air prior to commencing the conversion. An electrostatic precipitator is a commonly used dust removal technology on earth. Using this technology, dust particles that pass through receive an electrostatic charge by means of a corona discharge. The particles are then driven to a collector in a region of high electric field at the center of the precipitator. Experiments were conducted to develop a precipitator that will function properly in the Martian atmosphere, which has a very low pressure and is made up . of primarily carbon dioxide.

  9. Chemical composition of Martian fines

    NASA Technical Reports Server (NTRS)

    Clark, B. C.; Baird, A. K.; Weldon, R. J.; Tsusaki, D. M.; Schnabel, L.; Candelaria, M. P.

    1982-01-01

    Of the 21 samples acquired for the Viking X-ray fluorescence spectrometer, 17 were analyzed to high precision. Compared to typical terrestrial continental soils and lunar mare fines, the Martian fines are lower in Al, higher in Fe, and much higher in S and Cl concentrations. Protected fines at the two lander sites are almost indistinguishable, but concentration of the element S is somewhat higher at Utopia. Duricrust fragments, successfully acquired only at the Chryse site, invariably contained about 50% higher S than fines. No elements correlate positively with S, except Cl and possibly Mg. A sympathetic variation is found among the triad Si, Al, Ca; positive correlation occurs between Ti and Fe. Sample variabilities are as great within a few meters as between lander locations (4500 km apart), implying the existence of a universal Martian regolith component of constant average composition. The nature of the source materials for the regolith fines must be mafic to ultramafic.

  10. SNC Meteorites and Martian Reservoirs

    NASA Technical Reports Server (NTRS)

    Jones, J. H.

    2002-01-01

    The martian mantle is apparently heterogeneous, which opens the possibility that it is layered, with each layer convectively isolated. If this is correct, melt generation should occur either at thermal boundary layers or in plumes generated at those boundaries. Mantle layering may be a good means of slowing the planet's cooling rate, allowing young volcanism. Layering may also provide a means for keeping the crust and upper mantle cool, allowing the preservation of ancient variations in crustal thickness.

  11. Martian "microfossils" in lunar meteorites?

    PubMed

    Sears, D W; Kral, T A

    1998-07-01

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

  12. Martian "microfossils" in lunar meteorites?

    PubMed

    Sears, D W; Kral, T A

    1998-07-01

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

  13. Martian "microfossils" in lunar meteorites?

    NASA Astrophysics Data System (ADS)

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

    1998-07-01

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

  14. Yamato 980459: Crystallization of Martian Magnesian Magma

    NASA Technical Reports Server (NTRS)

    Koizumi, E.; Mikouchi, T.; McKay, G.; Monkawa, A.; Chokai, J.; Miyamoto, M.

    2004-01-01

    Recently, several basaltic shergottites have been found that include magnesian olivines as a major minerals. These have been called olivinephyric shergottites. Yamato 980459, which is a new martian meteorite recovered from the Antarctica by the Japanese Antarctic expedition, is one of them. This meteorite is different from other olivine-phyric shergottites in several key features and will give us important clues to understand crystallization of martian meteorites and the evolution of Martian magma.

  15. Assessing the volcanic probability of Martian landforms

    NASA Technical Reports Server (NTRS)

    Otoole, M.

    1982-01-01

    A table for use in identifying Martian land forms that may be volcanic in nature is presented. Eight types of known volcanic features and associations are described and each assigned a point value based on the degree to which it is thought to be characteristic of volcanoes. The system is applied to four well known Martian volcanoes and to other Martian features which may or may not be volcanic in origin.

  16. Martian Radiation Environment Experiment (MARIE)

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.

    1999-01-01

    Space radiation presents a very serious hazard to crews of interplanetary human missions. The two sources of this radiation are the galactic cosmic rays (GCR) and solar energetic particle (SEP) events. The GCR provides a steady source of low dose rate radiation that is primarily responsible for stochastic effects, such as cancer, and can effect the response of the central nervous system. Nuclear interactions of these components with the Martian atmosphere produces substantial flux of neutrons with high Radio Biological Effectiveness. The uncertainty in the knowledge of many fragmentation cross sections and their energy dependence required by radiation transport codes, uncertainties in the ambient radiation environment, and knowledge of the Martian atmosphere, lead to large enough uncertainties in the knowledge of calculated radiation dose in both free space (cruise phase), in Martian orbit, and on Martian surface. Direct measurements of radiation levels, the relative contributions of protons, neutrons, and heavy ions, and Martian atmospheric characteristics is thus a prerequisite for any human mission. An integrated suite of two spectrometers to provide these data will be described. The Orbiter spectrometer will measure the energy spectrum of SEP events from 15 to 500 MeV/n, and when combined with data from other space based instruments, such as the Advanced Composition Explorer (ACE), would provide accurate GCR spectra also. The Lander spectrometer would measure the absorbed dose rate, dose equivalent dose rate, and the linear energy transfer (LET) spectra and is capable of separating the relative contribution of these quantities from protons, neutrons, and high Z particles. There are two separate flight instruments, one for the Orbiter and one for the Lander, based on a common design of the backplane, the central processing unit (CPU), power supply, and onboard data storage. The Orbiter instrument consists of an energetic particle spectrometer that can measure

  17. Martian Neutron Energy Spectrometer (MANES)

    NASA Technical Reports Server (NTRS)

    Maurer, R. H.; Roth, D. R.; Kinnison, J. D.; Goldsten, J. O.; Fainchtein, R.; Badhwar, G.

    2000-01-01

    High energy charged particles of extragalactic, galactic, and solar origin collide with spacecraft structures and planetary atmospheres. These primaries create a number of secondary particles inside the structures or on the surfaces of planets to produce a significant radiation environment. This radiation is a threat to long term inhabitants and travelers for interplanetary missions and produces an increased risk of carcinogenesis, central nervous system (CNS) and DNA damage. Charged particles are readily detected; but, neutrons, being electrically neutral, are much more difficult to monitor. These secondary neutrons are reported to contribute 30-60% of the dose equivalent in the Shuttle and MIR station. The Martian atmosphere has an areal density of 37 g/sq cm primarily of carbon dioxide molecules. This shallow atmosphere presents fewer mean free paths to the bombarding cosmic rays and solar particles. The secondary neutrons present at the surface of Mars will have undergone fewer generations of collisions and have higher energies than at sea level on Earth. Albedo neutrons produced by collisions with the Martian surface material will also contribute to the radiation environment. The increased threat of radiation damage to humans on Mars occurs when neutrons of higher mean energy traverse the thin, dry Martian atmosphere and encounter water in the astronaut's body. Water, being hydrogeneous, efficiently moderates the high energy neutrons thereby slowing them as they penetrate deeply into the body. Consequently, greater radiation doses can be deposited in or near critical organs such as the liver or spleen than is the case on Earth. A second significant threat is the possibility of a high energy heavy ion or neutron causing a DNA double strand break in a single strike.

  18. Water and the Martian Polar Atmosphere

    NASA Technical Reports Server (NTRS)

    Richardson, Mark I.

    2005-01-01

    The contents of this report were focused on the dynamics of mixing processes in the Martian polar regions as a function of Martian season, and on direct study of water mixing within the atmosphere, and water exchange with surface ice deposits, especially along the retreating edge of the seasonal ice cap.

  19. MGS View of Martian Magnetosphere

    NASA Technical Reports Server (NTRS)

    Espley, Jared

    2012-01-01

    The solar wind's interaction with Mars has been studied for several decades. However, the scientific results from the Mars Global Surveyor (MGS) mission represented a very significant step forward in our understanding in this subject. Missions since MGS, including missions currently under development such as MAVEN, have built on MGS' results. In this presentation, I briefly discuss the historical context of MGS' results regarding the induced Martian magnetosphere. I then highlight the major scientific results from the MGS observations and showcase ongoing investigations using MGS data.

  20. Antarctica as a Martian model.

    NASA Technical Reports Server (NTRS)

    Vishniac, W. V.; Mainzer, S. E.

    1973-01-01

    Results of a survey of a variety of environments in the dry valleys of Antarctica, ranging from mountain crests to valley floors. The main purpose of the investigation was the determination of active microbial multiplication in the soil. A series of techniques was employed which permitted the detection of bacterial growth in situ. All evidence points to an active growth of micro-organisms in the Antarctic soil in all locations examined. The measurements were supported by electron micrographs of soil films which showed colonial growth covering soil particles. These findings suggest that Antarctica does not serve as a useful model for the Martian environment in evaluating quarantine standards.

  1. Boron enrichment in martian clay.

    PubMed

    Stephenson, James D; Hallis, Lydia J; Nagashima, Kazuhide; Freeland, Stephen J

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  2. Boron enrichment in martian clay.

    PubMed

    Stephenson, James D; Hallis, Lydia J; Nagashima, Kazuhide; Freeland, Stephen J

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  3. Boron Enrichment in Martian Clay

    PubMed Central

    Nagashima, Kazuhide; Freeland, Stephen J.

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  4. Chemical reactivity of the Martian soil

    NASA Technical Reports Server (NTRS)

    Zent, A. P.; Mckay, C. P.

    1992-01-01

    The Viking life sciences experimental packages detected extraordinary chemical activity in the martian soil, probably the result of soil-surface chemistry. At least one very strong oxidant may exist in the martian soil. The electrochemical nature of the martian soil has figured prominently in discussions of future life sciences research on Mars. Putative oxidants in the martian soil may be responsible for the destruction of organic material to considerable depth, precluding the recovery of reducing material that may be relic of early biological forms. Also, there have been serious expressions of concern regarding the effect that soil oxidants may have on human health and safety. The concern here has centered on the possible irritation of the respiratory system due to dust carried into the martian habitat through the air locks.

  5. Martian oceans, valleys and climate

    USGS Publications Warehouse

    Carr, M.H.

    2000-01-01

    The new Mars Global Surveyor altimetry shows that the heavily cratered southern hemisphere of Mars is 5 km higher that the sparely cratered plains of the northern hemisphere. Previous suggestions that oceans formerly occupied that northern plains as evidenced by shorelines are partly supported by the new data. A previously identified outer boundary has a wide range of elevations and is unlikely to be a shoreline but an inner contact with a narrow range of elevations is a more likely candidate. No shorelines are visible in the newly acquired, 2.5 metre/pixel imaging. Newly imaged valleys provide strong support for sustained or episodic flow of water across the Martian surface. A major surprise, however, is the near absence of valleys less than 100 m across. Martian valleys seemingly do not divide into ever smaller valleys as terrestrial valleys commonly do. This could be due to lack of precipitation or lack of surface runoff because of high infiltration rates. High erosion rates and supports warm climates and presence of large bodies of water during heavy bombardment. The climate history and fate of the water after heavy bombardment remain cotroversial.

  6. Origin of giant Martian polygons

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.; Hills, L. S.

    1992-01-01

    Extensive areas of the Martian northern plains in Utopia and Acidalia planitiae are characterized by 'polygonal terrane'. Polygonal terrane consists of material cut by complex troughs defining a pattern resembling mudcracks, columnar joints, or frost-wedge polygons on earth. However, the Martian polygons are orders of magnitude larger than these potential earth analogues, leading to severe mechanical difficulties for genetic models based on simple analogy arguments. Plate-bending and finite element models indicate that shrinkage of desiccating sediment or cooling volcanics accompanied by differential compaction over buried topography can account for the stresses responsible for polygon troughs as well as the large size of the polygons. Although trough widths and depths relate primarily to shrinkage, the large scale of the polygonl pattern relates to the spacing between topographic elevations on the surface buried beneath polygonal terrane material. Geological relationships favor a sedimentary origin for polygonal terrane material, but our model is not dependent on the specific genesis. Our analysis also suggests that the polygons must have formed at a geologically rapid rate.

  7. Why do Martian Magmas erupt?

    NASA Astrophysics Data System (ADS)

    Balta, J. B.; McSween, H. Y.

    2011-12-01

    Eruption of silicate lava, whether on Earth or another planet, requires that at some depth the melt has lower density than the surrounding rocks. As the densities of silicate liquids change during crystallization, whether a particular silicate liquid will erupt or be trapped at a level of neutral buoyancy is a complex yet fundamental issue for planetary dynamics. In general, 3 factors drive surface eruptions: inherent buoyancy relative to mantle phases, compositional evolution, and volatile contents. These factors manifest on Earth as terrestrial basalts commonly have compositions close to a density minimum [1]. Recent work has produced estimates of Martian parental magma compositions [2-5] based on shergottite meteorites and from Gusev crater. Using the MELTS algorithm [6] and other density calibrations, we simulated evolution of these liquids, focusing on density changes. For much of the crystallization path, density is controlled by FeO. All of the liquids begin with ρ ~ 2.8 g/cc at 1 bar, and the evolution of liquid density is controlled by the liquidus phases. At low pressures, olivine is the liquidus phase for each melt, and as FeO is not incompatible in olivine, olivine crystallization decreases liquid density, increasing buoyancy with crystallization. However, FeO is incompatible in pyroxene, and thus liquids crystallizing pyroxene become denser and less buoyant with crystallization, producing liquids with densities up to and above 3.0 g/cc. As the olivine-pyroxene saturation relationship is affected by pressure and chemistry, the identity of the liquidus phase and density evolution will vary between magmas. Without spreading centers, Mars has no location where the mantle approaches the surface, and it is likely that any magma which is denser than the crust will stall below or within that crust. The crystallization path of a liquid is a function of pressure, with pyroxene crystallizing first at P > 10 kbar (~80 km depth), close to the base of the Martian

  8. Comparison of Martian Meteorites and Martian Regolith as Shield Materials for Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Thibeault, Sheila A.; Simonsen, Lisa C.; Wilson, John W.

    1998-01-01

    Theoretical calculations of radiation attenuation due to energetic galactic cosmic rays behind Martian rock and Martian regolith material have been made to compare their utilization as shields for advanced manned missions to Mars because the detailed chemical signature of Mars is distinctly different from Earth. The modified radiation fields behind the Martian rocks and the soil model were generated by solving the Boltzmann equation using a HZETRN system with the 1977 Solar Minimum environmental model. For the comparison of the attenuation characteristics, dose and dose equivalent are calculated for the five different subgroups of Martian rocks and the Martian regolith. The results indicate that changes in composition of subgroups of Martian rocks have negligible effects on the overall shielding properties because of the similarity of their constituents. The differences for dose and dose equivalent of these materials relative to those of Martian regolith are within 0.5 and 1 percent, respectively. Therefore, the analysis of Martian habitat construction options using in situ materials according to the Martian regolith model composition is reasonably accurate. Adding an epoxy to Martian regolith, which changes the major constituents of the material, enhances shielding properties because of the added hydrogenous constituents.

  9. Magnetic and electrical properties of Martian particles

    NASA Technical Reports Server (NTRS)

    Olhoeft, G. R.

    1991-01-01

    The only determinations of the magnetic properties of Martian materials come from experiments on the two Viking Landers. The results suggest Martian soil containing 1 to 10 percent of a highly magnetic phase. Though the magnetic phase mineral was not conclusively identified, the predominate interpretation is that the magnetic phase is probably maghemite. The electrical properties of the surface of Mars were only measured remotely by observations with Earth based radar, microwave radiometry, and inference from radio-occultation of Mars orbiting spacecraft. No direct measurements of electrical properties on Martian materials have been performed.

  10. Martian Meteorites Record Surface Temperatures on Mars

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2005-07-01

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

  11. A Rainbow of Martian Elements

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graph or spectrum taken by the alpha particle X-ray spectrometer onboard the Mars Exploration Rover Spirit shows the variety of elements present in the soil at the rover's landing site. In agreement with past missions to Mars, iron and silicon make up the majority of the martian soil. Sulfur and chlorine were also observed as expected. Trace elements detected for the first time include zinc and nickel. These latter observations demonstrate the power of the alpha particle X-ray spectrometer to pick up the signatures of elements too faint to be seen before. The alpha particle X-ray spectrometer uses alpha particles and X-rays to measure the presence and abundance of all major rock-forming elements except hydrogen.

  12. Geophysics of Martian Periglacial Processes

    NASA Technical Reports Server (NTRS)

    Mellon, Michael T.

    2004-01-01

    Through the examination of small-scale geologic features potentially related to water and ice in the martian subsurface (specifically small-scale polygonal ground and young gully-like features), determine the state, distribution and recent history of subsurface water and ice on Mars. To refine existing models and develop new models of near-surface water and ice, and develop new insights about the nature of water on Mars as manifested by these geologic features. Through an improved understanding of potentially water-related geologic features, utilize these features in addressing questions about where to best search for present day water and what space craft may encounter that might facilitate or inhibit the search for water.

  13. Martian Sunrise at Utopia Planitia

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A Martian sunrise was captured in this Viking 2 Lander picture taken June 14, 1978, at the spacecraft's Utopia Planitia landing site. The data composing this image were acquired just as the Sun peaked over the horizon on the Lander's 631st sol (Martian solar day). Pictures taken at dawn (or dusk) are quite dark except where the sky is brightened above the Sun's position. The glow in the sky results as light from the Sun is scattered and preferentially absorbed by tiny particles of dust and ice in the atmosphere. When the Viking cameras are calibrated for darker scenes, the 'sky glow' tends to saturate their sensitivity and produce the bright regions seen here. The 'banding' and color separation effects are also artifacts, rather than real features, and are introduced because the cameras are not able to record continuous gradations of light. The cameras must represent such gradations in steps (bands) of brightness and color, and the process sometimes produces some 'false' colors within the bands. The scattering of light closest to the Sun's position tends to enhance blue wavelengths. The narrowing sky glow nearer the horizon above the Sun's position occurs as a result of light extinction. At that elevation, the optical path of sunlight through the atmosphere is at its longest penetration angle, and a substantial portion of the light is simply prevented from reaching the cameras by the dust, ice particles and other material in its way.

    NASA's Langley Research Center was the primary and extended mission manager; JPL assumed management for continued mission operations.

  14. Evaporites: Analogs for Martian Life

    NASA Astrophysics Data System (ADS)

    Mancinelli, R.; Fahlen, T.; Langheim, R.

    Recent data from Mars missions suggest that Mars almost certainly had abundant liquid water on its surface at some time in the past. As a result, Mars has emerged as a key Solar System target which could have harbored some form of life in its past and which could perhaps still possess some remnant in brine containing permafrost. As mars lost its atmosphere it became cold and dry. If any water remained to form permafrost high salt brine pockets would have formed within the ice. These brine pockets may either be an "oasis" for an extant Martian biota, or the last refuge of an extinct Martian biota. Eventually these brine pockets would have dried to form evaporites. Evaporites are deposits that result from the evaporation water containing salts, on earth consisting primarily of halite (NaCl) gypsum (CaSO4 . 2H2O) or anhydrite (CaSO4). Evaporites containing bacterial and algal assemblages exist on earth today and are well-known in the fossil record. The most likely organism type to survive in a salty brine or evaporite is a halophile. Washed mid-log phase and stationary phase cultures of Halobacterium salinarium either suspended in brine (25% NaCl), dried, or in the form of a paste prepared from a centrifuge pellet were exposed to -20 oC or -80 oC. As a control, E. coli was treated similarly except was suspended in 0.8% NaCl or deionized water. Periodically samples of the cells were removed and tested for survival. Preliminary data from these experiments suggest that under these conditions Halophiles can survive exposure to such low temperatures better than E. coli. This would suggest that halophiles may survive in permafrost containing evporites.

  15. Manganese, Metallogenium, and Martian Microfossils

    NASA Technical Reports Server (NTRS)

    Stein, L. Y.; Nealson, K. H.

    1999-01-01

    Manganese could easily be considered an abundant element in the Martian regolith, assuming that the composition of martian meteorites reflects the composition of the planet. Mineralogical analyses of 5 SNC meteorites have revealed an average manganese oxide concentration of 0.48%, relative to the 0.1% concentration of manganese found in the Earth's crust. On the Earth, the accumulation of manganese oxides in oceans, soils, rocks, sedimentary ores, fresh water systems, and hydrothermal vents can be largely attributed to microbial activity. Manganese is also a required trace nutrient for most life forms and participates in many critical enzymatic reactions such as photosynthesis. The wide-spread process of bacterial manganese cycling on Earth suggests that manganese is an important element to both geology and biology. Furthermore, there is evidence that bacteria can be fossilized within manganese ores, implying that manganese beds may be good repositories for preserved biomarkers. A particular genus of bacteria, known historically as Metallogenium, can form star-shaped manganese oxide minerals (called metallogenium) through the action of manganese oxide precipitation along its surface. Fossilized structures that resemble metallogenium have been found in Precambrian sedimentary formations and in Cretaceous-Paleogene cherts. The Cretaceous-Paleogene formations are highly enriched in manganese and have concentrations of trace elements (Fe, Zn, Cu, and Co) similar to modern-day manganese oxide deposits in marine environments. The appearance of metallogenium-like fossils associated with manganese deposits suggests that bacteria may be preserved within the minerals that they form. Additional information is contained in the original extended abstract.

  16. Magnetic Fluctuations in the Martian Ionosphere

    NASA Technical Reports Server (NTRS)

    Espley, Jared

    2010-01-01

    The Martian ionosphere is influenced by both the solar wind and the regional magnetic fields present in the Martian crust. Both influences ought to cause time variable changes in the magnetic fields present in the ionosphere. I report observations of these magnetic field fluctuations in the Martian ionosphere. I use data from the Mars Global Surveyor magnetometer instrument. By using data from the aerobraking low altitude passes (approx. 200 km) I find that there are numerous fluctuations both near and far from the strong crustal sources. Using data from the 400 km altitude mapping phase (which is near the topside of the primary ionosphere), I look at the comparative strength of the fluctuations relative to the solar wind and temporal variations. I discuss which wave modes and instabilities could be contributing to these fluctuations. I also discuss the implications of these fluctuations for understanding energy transfer in the Martian system and the effects on atmospheric escape.

  17. Identifying Fossil Bacteria in Martian Materials

    NASA Technical Reports Server (NTRS)

    Westall, F.; McKay, D. S.; Gibson, E. K., Jr.

    1999-01-01

    Within the next decade, robotic missions are going to Mars with the search for evidence for extant and extinct life as at least one of the mission objectives. Moreover, the first Martian samples will be returned to Earth in 2008. It is therefore imperative that we can be certain that we can identify life in Martian rocks. In this paper we will not be discussing extant life but will concentrate on fossil life.

  18. Phosphates and Carbon in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Mojzsis, Stephen J.

    2000-01-01

    This paper proposes tests for exobiological examination of samples prior to obtaining martian rocks of known provenance via future sample-return missions. If we assume that all of the secondary minerals in martian meteorite ET79001 were indeed cogenetic and originate from Mars, we list conclusions that can be drawn that are of exobiological interest. This work serves as a preamble for the subsequent work listed below.

  19. Wind tunnel simulation of Martian sand storms

    NASA Technical Reports Server (NTRS)

    Greeley, R.

    1980-01-01

    The physics and geological relationships of particles driven by the wind under near Martian conditions were examined in the Martian Surface Wind Tunnel. Emphasis was placed on aeolian activity as a planetary process. Threshold speeds, rates of erosion, trajectories of windblown particles, and flow fields over various landforms were among the factors considered. Results of experiments on particles thresholds, rates of erosion, and the effects of electrostatics on particles in the aeolian environment are presented.

  20. Magnetism and the putative early Martian life

    NASA Astrophysics Data System (ADS)

    Rochette, P.

    2001-08-01

    A short critical review is provided on three questions linking magnetism and the putative early Mars life. Was there a large internal Martian magnetic field, during which period, and is it a requisite for life? What is the origin of the paleomagnetic signal of Martian meteorites, including ALH84001? What is the present credibility of the case for fossil bacterial magnetite grains in ALH84001?

  1. Ice-Ridge Pile Up and the Genesis of Martian "Shorelines"

    NASA Technical Reports Server (NTRS)

    Barnhart, C. J.; Tulaczyk, S.; Asphaug, E.; Kraal, E. R.; Moore, J.

    2005-01-01

    Unique geomorphologic features such as basin terraces exhibiting topographic continuity have been found within several Martian craters as shown in Viking, MOC, and THEMIS images. These features, showing similarity to terrestrial shorelines, have been mapped and cataloged with significant effort [1]. Currently, open wave action on the surface of paleolakes has been hypothesized as the geomorphologic agent responsible for the generation of these features [2]. As consequence, feature interpretations, including shorelines, wave-cut benches, and bars are, befittingly, lacustrine. Because such interpretations and their formation mechanisms have profound implications for the climate and potential biological history of Mars, confidence is crucial. The insight acquired through linked quantitative modeling of geomorphologic agents and processes is key to accurately interpreting these features. In this vein, recent studies [3,4] involving the water wave energy in theoretical open water basins on Mars show minimal erosional effects due to water waves under Martian conditions. Consequently, sub-glacial lake flattens the surface, produces a local velocity increase over the lake, and creates a deviation of the ice flow from the main flow direction [11]. These consequences of ice flow are observed at Lake Vostok, Antarctica an excellent Martian analogue [11]. Martian observations include reticulate terrain exhibiting sharp inter-connected ridges speculated to reflect the deposition and reworking of ice blocks at the periphery of ice-covered lakes throughout Hellas [12]. Our model determines to what extent ice, a terrestrial geomorphologic agent, can alter the Martian landscape. Method: We study the evolution of crater ice plugs as the formation mechanism of surface features frequently identified as shorelines. In particular, we perform model integrations involving parameters such as ice slope and purity, atmospheric pressure and temperature, crater shape and composition, and an

  2. On the weathering of Martian igneous rocks

    NASA Technical Reports Server (NTRS)

    Dreibus, G.; Waenke, H.

    1992-01-01

    Besides the young crystallization age, one of the first arguments for the martian origin of shergottite, nakhlite, and chassignite (SNC) meteorites came from the chemical similarity of the meteorite Shergotty and the martian soil as measured by Viking XRF analyses. In the meantime, the discovery of trapped rare gas and nitrogen components with element and isotope ratios closely matching the highly characteristic ratios of the Mars atmosphere in the shock glasses of shergottite EETA79001 was further striking evidence that the SNC's are martian surface rocks. The martian soil composition as derived from the Viking mission, with its extremely high S and Cl concentrations, was interpreted as weathering products of mafic igneous rocks. The low SiO2 content and the low abundance of K and other trace elements in the martian soils point to a mafic crust with a considerably smaller degree of fractionation compared to the terrestrial crust. However, the chemical evolution of the martian regolith and soil in respect to surface reaction with the planetary atmosphere or hydrosphere is poorly understood. A critical point in this respect is that the geochemical evidence as derived from the SNC meteorites suggests that Mars is a very dry planet that should have lost almost all its initially large water inventory during its accretion.

  3. Rocket dust storms and detached layers in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Spiga, A.; Faure, J.; Madeleine, J.; Maattanen, A. E.; Forget, F.

    2012-12-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling with radiatively-active transported dust to predict the evolution of a local dust storm monitored by OMEGA onboard Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, in lieu of latent heating in moist convection on Earth. We propose to use the terminology "rocket dust storm", or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30 to 50 km). Combined to horizontal transport by large-scale winds, rocket dust storms form detached layers of dust reminiscent of those observed with instruments onboard Mars Global Surveyor and Mars Reconnaissance Orbiter. Detached layers are stable over several days owing to nighttime sedimentation being unable to counteract daytime convective transport, and to the resupply of convective energy at sunrise. The peak activity of rocket dust storms is expected in low-latitude regions at clear season, which accounts for the high-altitude tropical dust maximum unveiled by Mars Climate Sounder. Our findings on dust-driven deep convection have strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.ensity-scaled dust optical depth at local times 1400 1600 and 1800 (lat 2.5°S, Ls 135°) hortwave heating rate at local time 1500 and latitude 2.5°S.

  4. Blue moons and Martian sunsets.

    PubMed

    Ehlers, Kurt; Chakrabarty, Rajan; Moosmüller, Hans

    2014-03-20

    The familiar yellow or orange disks of the moon and sun, especially when they are low in the sky, and brilliant red sunsets are a result of the selective extinction (scattering plus absorption) of blue light by atmospheric gas molecules and small aerosols, a phenomenon explainable using the Rayleigh scattering approximation. On rare occasions, dust or smoke aerosols can cause the extinction of red light to exceed that for blue, resulting in the disks of the sun and moon to appear as blue. Unlike Earth, the atmosphere of Mars is dominated by micron-size dust aerosols, and the sky during sunset takes on a bluish glow. Here we investigate the role of dust aerosols in the blue Martian sunsets and the occasional blue moons and suns on Earth. We use the Mie theory and the Debye series to calculate the wavelength-dependent optical properties of dust aerosols most commonly found on Mars. Our findings show that while wavelength selective extinction can cause the sun's disk to appear blue, the color of the glow surrounding the sun as observed from Mars is due to the dominance of near-forward scattering of blue light by dust particles and cannot be explained by a simple, Rayleigh-like selective extinction explanation.

  5. Martian Magnets Under the Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Spirit acquired this microscopic imager view of its capture magnet on sol 92 (April 6, 2004). Both Spirit and the Mars Exploration Rover Opportunity are equipped with a number of magnets. The capture magnet, as seen here, has a stronger charge than its sidekick, the filter magnet. The lower-powered filter magnet captures only the most magnetic airborne dust with the strongest charges, while the capture magnet picks up all magnetic airborne dust.

    The magnets' primary purpose is to collect the martian magnetic dust so that scientists can analyze it with the rovers' Moessbauer spectrometers. While there is plenty of dust on the surface of Mars, it is difficult to confirm where it came from, and when it was last airborne. Because scientists are interested in learning about the properties of the dust in the atmosphere, they devised this dust-collection experiment.

    The capture magnet is about 4.5 centimeters (1.8 inches) in diameter and is constructed with a central cylinder and three rings, each with alternating orientations of magnetization. Scientists have been monitoring the continual accumulation of dust since the beginning of the mission with panoramic camera and microscopic imager images. They had to wait until enough dust accumulated before they could get a Moessbauer spectrometer analysis. The results of that analysis, performed on sol 92, have not been sent back to Earth yet.

  6. Morning Frost on Martian Surface

    NASA Technical Reports Server (NTRS)

    2008-01-01

    A thin layer of water frost is visible on the ground around NASA's Phoenix Mars Lander in this image taken by the Surface Stereo Imager at 6 a.m. on Sol 79 (August 14, 2008), the 79th Martian day after landing. The frost begins to disappear shortly after 6 a.m. as the sun rises on the Phoenix landing site.

    The sun was about 22 degrees above the horizon when the image was taken, enhancing the detail of the polygons, troughs and rocks around the landing site.

    This view is looking east southeast with the lander's eastern solar panel visible in the bottom lefthand corner of the image. The rock in the foreground is informally named 'Quadlings' and the rock near center is informally called 'Winkies.'

    This false color image has been enhanced to show color variations.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. Blue moons and Martian sunsets.

    PubMed

    Ehlers, Kurt; Chakrabarty, Rajan; Moosmüller, Hans

    2014-03-20

    The familiar yellow or orange disks of the moon and sun, especially when they are low in the sky, and brilliant red sunsets are a result of the selective extinction (scattering plus absorption) of blue light by atmospheric gas molecules and small aerosols, a phenomenon explainable using the Rayleigh scattering approximation. On rare occasions, dust or smoke aerosols can cause the extinction of red light to exceed that for blue, resulting in the disks of the sun and moon to appear as blue. Unlike Earth, the atmosphere of Mars is dominated by micron-size dust aerosols, and the sky during sunset takes on a bluish glow. Here we investigate the role of dust aerosols in the blue Martian sunsets and the occasional blue moons and suns on Earth. We use the Mie theory and the Debye series to calculate the wavelength-dependent optical properties of dust aerosols most commonly found on Mars. Our findings show that while wavelength selective extinction can cause the sun's disk to appear blue, the color of the glow surrounding the sun as observed from Mars is due to the dominance of near-forward scattering of blue light by dust particles and cannot be explained by a simple, Rayleigh-like selective extinction explanation. PMID:24663457

  8. Martian Polar Expeditions: Problems and Solutions

    NASA Astrophysics Data System (ADS)

    Cockell, Charles S.

    2001-12-01

    The Martian polar ice caps are regions of substantial scientific interest, being the most dynamic regions of Mars. They are volatile sinks and thus closely linked to Martian climatic conditions. Because of their scale and the precedent set by the past history of polar exploration on Earth, it is likely that an age of polar exploration will emerge on the surface of Mars after the establishment of a capable support structure at lower latitudes. Expeditions might be launched either from a lower latitude base camp or from a human-tended polar base. Based on previously presented expeditionary routes to the Martian poles, in this paper a "spiral in-spiral out" unsupported transpolar assault on the Martian north geographical pole is used as a Reference expedition to propose new types of equipment for the human polar exploration of Mars. Martian polar "ball" tents and "hover" modifications to the Nansen sledge for sledging on CO 2-containing water ice substrates under low atmospheric pressures are suggested as elements for the success of these endeavours. Other challenges faced by these expeditions are quantitatively and qualitatively addressed.

  9. Photovoltaic array for Martian surface power

    NASA Technical Reports Server (NTRS)

    Appelbaum, J.; Landis, G. A.

    1992-01-01

    Missions to Mars will require electric power. A leading candidate for providing power is solar power produced by photovoltaic arrays. To design such a power system, detailed information on solar-radiation availability on the Martian surface is necessary. The variation of the solar radiation on the Martian surface is governed by three factors: (1) variation in Mars-Sun distance; (2) variation in solar zenith angle due to Martian season and time of day; and (3) dust in the Martian atmosphere. A major concern is the dust storms, which occur on both local and global scales. However, there is still appreciable diffuse sunlight available even at high opacity, so that solar array operation is still possible. Typical results for tracking solar collectors are also shown and compared to the fixed collectors. During the Northern Hemisphere spring and summer the isolation is relatively high, 2-5 kW-hr/sq m-day, due to the low optical depth of the Martian atmosphere. These seasons, totalling a full terrestrial year, are the likely ones during which manned mission will be carried out.

  10. Martian polar expeditions: problems and solutions.

    PubMed

    Cockell, C S

    2001-12-01

    The Martian polar ice caps are regions of substantial scientific interest, being the most dynamic regions of Mars. They are volatile sinks and thus closely linked to Martian climatic conditions. Because of their scale and the precedent set by the past history of polar exploration on Earth, it is likely that an age of polar exploration will emerge on the surface of Mars after the establishment of a capable support structure at lower latitudes. Expeditions might be launched either from a lower latitude base camp or from a human-tended polar base. Based on previously presented expeditionary routes to the Martian poles, in this paper a "spiral in-spiral out" unsupported transpolar assault on the Martian north geographical pole is used as a Reference expedition to propose new types of equipment for the human polar exploration of Mars. Martian polar "ball" tents and "hover" modifications to the Nansen sledge for sledging on CO2-containing water ice substrates under low atmospheric pressures are suggested as elements for the success of these endeavours. Other challenges faced by these expeditions are quantitatively and qualitatively addressed.

  11. Fractionated martian atmosphere in the nakhlites?

    NASA Technical Reports Server (NTRS)

    Drake, Michael J.; Swindle, Timothy D.; Owen, Tobias; Musselwhite, Donald S.

    1994-01-01

    Considerable evidence points to a martian origin of the shergottite-nakhlite-chassignite (SNC) meteorites. Noble gas isotopic compositions have been measured in most SNC meteorites. The Xe-129/Xe-132 vs. Kr-84/Xe-132 ratios in Chassigny, most shergottites, and lithology C of EETA 79001 define a linear array. This array is thought to be a mixing line between martian mantle and martian atmosphere. One of the SNC meteorites, Nakhla, contains a leachable component that has an elevated Xe-129/Xe-132 ratio relative to its Kr-84/Xe-132 ratio when compared to this approximately linear array. The leachable component probably consists in part of iddingsite, an alteration product produced by interaction of olivine with aqueous fluid at temperatures lower than 150 C. The elevated Xe isotopic ratio may represent a distinct reservoir in the martian crust or mantle. More plausibly, it is elementally fractionated martian atmosphere. Formation of sediments fractionates the noble gases in the correct direction. The range of sediment/atmosphere fractionation factors is consistent with the elevated Xe-129/Xe-132 component in Nakhla being contained in iddingsite, a low temperature weathering product. The crystallization age of Nakhla is 1.3 Ga. Its low-shock state suggests that it was ejected from near the surface of Mars. As liquid water is required for the formation of iddingsite, these observations provide further evidence for the near surface existence of aqueous fluids on Mars more recently than 1.3 Ga.

  12. Martian hillside gullies and icelandic analogs

    NASA Astrophysics Data System (ADS)

    Hartmann, William K.; Thorsteinsson, Thorsteinn; Sigurdsson, Freysteinn

    2003-04-01

    We report observations of Icelandic hillside gully systems that are near duplicates of gullies observed on high-latitude martian hillsides. The best Icelandic analogs involve basaltic talus slopes at the angle of repose, with gully formation by debris flows initiated by ground water saturation, and/or by drainage of water from upslope cliffs. We report not only the existence of Mars analog gullies, but also an erosional sequence of morphologic forms, found both on Mars and in Iceland. The observations support hypotheses calling for creation of martian gullies by aqueous processes. Issues remain whether the water in each case comes only from surficial sources, such as melting of ground ice or snow, or from underground sources such as aquifers that gain surface access in hillsides. Iceland has many examples of the former, but the latter mechanism is not ruled out. Our observations are consistent with the martian debris flow mechanism of F. Costard et al. (2001c, Science295, 110-113), except that classic debris flows begin at midslope more frequently than on Mars. From morphologic observations, we suggest that some martian hillside gully systems not only involve significant evolution by extended erosive activity, but gully formation may occur in episodes, and the time interval since the last episode is considerably less than the time interval needed to erase the gully through normal martian obliteration processes.

  13. Methane Trapping Capacity of the Early Martian Cryosphere

    NASA Astrophysics Data System (ADS)

    Lasue, J.; Langlais, B.; Quesnel, Y.; Chassefière, E.

    2014-07-01

    We demonstrate that the methane trapping capacity of the early martian cryosphere is comparable to the quantity possibly released by the early serpentinization that would have been necessary to generate the observed martian remanent magnetic field.

  14. Evidence for methane in Martian meteorites

    PubMed Central

    Blamey, Nigel J. F.; Parnell, John; McMahon, Sean; Mark, Darren F.; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R. M.; Banerjee, Neil R.; Flemming, Roberta L.

    2015-01-01

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity. PMID:26079798

  15. Life on Mars: Evidence from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    McKay, David S.; Thomas-Keptra, Katie L.; Clemett, Simon J.; Gibson, Everett K., Jr.; Spencer, Lauren; Wentworth, Susan J.

    2009-01-01

    New data on martian meteorite 84001 as well as new experimental studies show that thermal or shock decomposition of carbonate, the leading alternative non-biologic explanation for the unusual nanophase magnetite found in this meteorite, cannot explain the chemistry of the actual martian magnetites. This leaves the biogenic explanation as the only remaining viable hypothesis for the origin of these unique magnetites. Additional data from two other martian meteorites show a suite of biomorphs which are nearly identical between meteorites recovered from two widely different terrestrial environments (Egyptian Nile bottomlands and Antarctic ice sheets). This similarity argues against terrestrial processes as the cause of these biomorphs and supports an origin on Mars for these features.

  16. Radiosondes for Characterizing the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Schumacher, D. M.; Dorney, D. J.; McGrath, M. A.

    2012-01-01

    The National Weather Service (NWS) releases approximately 75,000 radiosondes each year to measure pressure, altitude, temperature, relative humidity, wind and cosmic radiation [1]. The data obtained from these measurements have led to a more thorough understanding of the Earth s lower atmosphere. On the contrary, there have been only six fully successful landings on Mars, and there is much less known about the variations in winds, density, etc., in the mid-regions of the Martian atmosphere (see Fig. 1). This data is vital to understanding Martian weather and the development of Mars landers for larger payloads [2,3,4]. Mars has too much atmosphere to land like is done on the moon, and too little atmosphere to land like is done on Earth. It is suggested that radiosondes could be added as secondary payloads on Mars missions and used to map physical properties in the different regions of the Martian atmosphere.

  17. Evidence for methane in Martian meteorites

    NASA Astrophysics Data System (ADS)

    Blamey, Nigel J. F.; Parnell, John; McMahon, Sean; Mark, Darren F.; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R. M.; Banerjee, Neil R.; Flemming, Roberta L.

    2015-06-01

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity.

  18. Evidence for methane in Martian meteorites.

    PubMed

    Blamey, Nigel J F; Parnell, John; McMahon, Sean; Mark, Darren F; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R M; Banerjee, Neil R; Flemming, Roberta L

    2015-01-01

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity. PMID:26079798

  19. Chemical evolution of the early Martian hydrosphere

    NASA Technical Reports Server (NTRS)

    Schaefer, M. W.

    1990-01-01

    The chemical evolution of the early Martian hydrosphere is discussed. The early Martian ocean can be modeled as a body of relatively pure water in equilibrium with a dense carbon dioxide atmosphere. The chemical weathering of lavas, pyroclastic deposits, and impact melt sheets would have the effect of neutralizing the acidity of the juvenile water. As calcium and other cations are added to the water by chemical weathering, they are quickly removed by the precipitation of calcium carbonate and other minerals, forming a deposit of limestone beneath the surface of the ocean. As the atmospheric carbon dioxide pressure and the temperature decrease, the Martian ocean would be completely frozen. Given the scenario for the chemical evolution of the northern lowland plains of Mars, it should be possible to draw a few conclusions about the expected mineralogy and geomorphology of this regions.

  20. Evidence for methane in Martian meteorites.

    PubMed

    Blamey, Nigel J F; Parnell, John; McMahon, Sean; Mark, Darren F; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R M; Banerjee, Neil R; Flemming, Roberta L

    2015-06-16

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity.

  1. A Hypothesis for the Abiotic and Non-Martian Origins of Putative Signs of Ancient Martian Life in ALH84001

    NASA Technical Reports Server (NTRS)

    Treiman, Allan H.

    2001-01-01

    Putative evidence of martian life in ALH84001 can be explained by abiotic and non-martian processes consistent with the meteorite's geological history. Additional information is contained in the original extended abstract.

  2. Estimation of high altitude Martian dust parameters

    NASA Astrophysics Data System (ADS)

    Pabari, Jayesh; Bhalodi, Pinali

    2016-07-01

    Dust devils are known to occur near the Martian surface mostly during the mid of Southern hemisphere summer and they play vital role in deciding background dust opacity in the atmosphere. The second source of high altitude Martian dust could be due to the secondary ejecta caused by impacts on Martian Moons, Phobos and Deimos. Also, the surfaces of the Moons are charged positively due to ultraviolet rays from the Sun and negatively due to space plasma currents. Such surface charging may cause fine grains to be levitated, which can easily escape the Moons. It is expected that the escaping dust form dust rings within the orbits of the Moons and therefore also around the Mars. One more possible source of high altitude Martian dust is interplanetary in nature. Due to continuous supply of the dust from various sources and also due to a kind of feedback mechanism existing between the ring or tori and the sources, the dust rings or tori can sustain over a period of time. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, it is mystery how dust has reached to such high altitudes. Estimation of dust parameters before-hand is necessary to design an instrument for the detection of high altitude Martian dust from a future orbiter. In this work, we have studied the dust supply rate responsible primarily for the formation of dust ring or tori, the life time of dust particles around the Mars, the dust number density as well as the effect of solar radiation pressure and Martian oblateness on dust dynamics. The results presented in this paper may be useful to space scientists for understanding the scenario and designing an orbiter based instrument to measure the dust surrounding the Mars for solving the mystery. The further work is underway.

  3. A search for nitrates in Martian meteorites

    NASA Astrophysics Data System (ADS)

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

    1995-03-01

    Martian atmospheric nitrogen is highly enriched in N-15; nitrates formed by interaction of the atmosphere with the Martian regolith should therefore also be characterized by an elevated delta N-15 value. A search has been made for nitrates in two Martian meteorites, in order to determine the extent of possible regolith-atmosphere interaction. Shock-produced glass from the Elephant Moraine (EET) A79001 shergottite (E1,149) and a water-soluble extract from Nakhla were analyzed by Fourier transform infrared (FTIR) spectroscopy and stepped combustion-stable isotope mass spectrometry. FTIR of both meteorites had features at 1375/cm and 1630/cm, consistent with nitrates. On account of their low thermal stability, nitrates break down at temperatures below 600 C; in this temperature range, E1,149 yeilded approximately 1250 ppb nitrogen with delta N-15 -8 +/- 5%. If this nitrogen is from a nitrate, then it cannot be distinquished from terrestial salts by its isotopic composition. The water-soluble extract from Nakhla also released nitrogen at low temperatures, approximately 17 ppb with delta N-15 approximately -11 +/- 4%. Since Nakhla is an observed 'fall', this is unlikely to be a terrestial weathering product. Nitrates apparently occur in E1,149 and Nakhla, but in very low abundance, and their origin is unclear. The isotopic composition of the salts, which is within the range of that proposed for Martian magmatic volatiles, is far removed from that of nitrogen in the present-day Martian atmosphere. If the nitrates are Martian in origin, they did not form in recent times from reactions involving atmospheric gases. Rather, the nitrates could be the result of an earlier episode of atmospheric interaction with the regolith, or with implantation of magmatic volatiles introduced during degassing.

  4. Martian surface paleotemperatures from thermochronology of meteorites.

    PubMed

    Shuster, David L; Weiss, Benjamin P

    2005-07-22

    The temporal evolution of past martian surface temperatures is poorly known. We used thermochronology and published noble gas and petrographic data to constrain the temperature histories of the nakhlites and martian meteorite ALH84001. We found that the nakhlites have not been heated to more than 350 degrees C since they formed. Our calculations also suggest that for most of the past 4 billion years, ambient near-surface temperatures on Mars are unlikely to have been much higher than the present cold (<0 degrees C) state. PMID:16040703

  5. Martian Surface Paleotemperatures from Thermochronology of Meteorites

    NASA Astrophysics Data System (ADS)

    Shuster, David L.; Weiss, Benjamin P.

    2005-07-01

    The temporal evolution of past martian surface temperatures is poorly known. We used thermochronology and published noble gas and petrographic data to constrain the temperature histories of the nakhlites and martian meteorite ALH84001. We found that the nakhlites have not been heated to more than 350°C since they formed. Our calculations also suggest that for most of the past 4 billion years, ambient near-surface temperatures on Mars are unlikely to have been much higher than the present cold (<0°C) state.

  6. Martian Moon Eclipses Sun, in Stages

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This panel illustrates the transit of the martian moon Phobos across the Sun. It is made up of images taken by the Mars Exploration Rover Opportunity on the morning of the 45th martian day, or sol, of its mission. This observation will help refine our knowledge of the orbit and position of Phobos. Other spacecraft may be able to take better images of Phobos using this new information. This event is similar to solar eclipses seen on Earth in which our Moon passes in front of the Sun. The images were taken by the rover's panoramic camera.

  7. Deciphering Martian climatic history using returned samples

    NASA Technical Reports Server (NTRS)

    Paige, D. A.; Krieger, D. B.; Brigham, C. A.

    1988-01-01

    By necessity, a Mars sample return mission must sample the upper few meters of the Martian surface. This material was subjected to a wide variety of physical processes. Presently, the most important processes are believed to be wind-driven erosion and deposition, and water ice accumulation at higher latitudes. A sample return mission represents an opportunity to better understand and quantify these important geological processes. By obtaining sample cores at key locations, it may be possible to interpret much of recent Martian climatic history.

  8. Evolution of the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Pepin, R. O.

    1993-01-01

    Evolution of Mars' noble gases through two stages of hydrodynamic escape early in planetary history has been proposed previously by the author. In the first evolutionary stage of this earlier model, beginning at a solar age of approximately 50 m.y., fractionating escape of a H2-rich primordial atmosphere containing CO2, N2, and the noble gases in roughly the proportions found in primitive carbonaceous (CI) chondrites is driven by intense extreme-ultraviolet (EUV) leads to a long (approximately 80 m.y.) period of quiescence, followed by an abrupt degassing of remnant H2, CO2, and N2 from the mantle and of solar-composition noble gases lighter than Xe from the planet's volatile-rich accretional core. Degassed H refuels hydrodynamic loss in a waning but still potent solar EUV flux. Atmospheric Xe, Kr, and Ar remaining at the end of this second escape stage, approximately 4.2 G.y. ago, have evolved to their present-day abundances and compositions. Residual Ne continues to be modified by accretion of solar wind gases throughout the later history of the planet. This model does not address a number of processes that now appear germane to Martian atmospheric history. One, gas loss and fractionation by sputtering, has recently been shown to be relevant. Another, atmospheric erosion, appears increasingly important. In the absence then of a plausible mechanism, the model did not consider the possibility of isotopic evolution of noble gases heavier than Ne after the termination of hydrodynamic escape. Subsequent non-thermal loss of N was assumed, in an unspecified way, to account for the elevation of N from the model value of approximately 250 percent at the end of the second escape stage to approximately 620 percent today. Only qualitative attention was paid to the eroding effects of impact on abundances of all atmophilic species prior to the end of heavy bombardment approximately 3.8 G.y. ago. No attempt was made to include precipitation and recycling of carbonates in

  9. Evidence for Ancient Martian Life

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K., Jr.

    1999-01-01

    Three SNC meteorites ranging in age from 4.5 Ga. to 1.3 Ga. to 165 m.y. contain features suggestive, of past biogenic activity on Mars. Because we do not know what past martian life looks like or its physical or chemical properties, the only tools or criteria which the scientific community have to evaluate evidence of past life is to use evidence for early life on earth. There are features within ALH8400 I's carbonate globules and the pre-terrestrial aqueous alteration phases of Nakhla and Shergotty which have been interpreted as possible evidence for past life on early Mars. Eight criteria have been established for the recognition of past life within terrestrial geologic samples. They are: (a) geologic context; (b) sample's age and stratigraphic location (c) cellular morphology; (d) colonies; (e) biominerals; (f) stable isotope patterns unique to biology; (g) organic biomarkers; (h) indigenous features to the sample. For general acceptance of past life, essentially most or all of these criteria must be met. Studies have shown conclusively that the reduced carbon components in ALH84001 and Nakhla are indigenous to the meteorites and are not terrestrial contaminants Based on carbon isotopic compositions and mineralogical morphologies, there is no question or disagreement that the carbonate globules or embedded magnetites in ALH84001 and the pre-terrestrial aqueous alteration products in Nakhla and Shergotty were formed on Mars. Possible microfossil structures and some reduced carbon components in the carbonates and pre-terrestrial aqueous alteration products are, therefore, almost certainly indigenous, but other possible evidence for life (e.g. amino acids) may be a result of terrestrial contamination Our hypothesis of possible early life on Mars was presented in August 1996. Today, we believe it stands stronger than when originally presented. To date, no fatal strikes have been made to any of our original four lines of evidence. While details of the hypothesis are

  10. Water Retention of Extremophiles and Martian Soil Simulants Under Close to Martian Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Jänchen, J.; Bauermeister, A.; Feyh, N.; deVera, J.-P.

    2012-05-01

    We report data about interaction of moisture with soil simulants and extremophiles under Martian environmental conditions contributing on atmosphere/surface modelling and on effects determining the water inventory of the upper soil layer of Mars.

  11. Ion Microprobe Measurements of Carbon Isotopes in Martian Phosphates: Insights into the Martian Mantle

    NASA Astrophysics Data System (ADS)

    Goreva, J. S.; Leshin, L. A.; Guan, Y.

    2003-03-01

    In-situ measurements of C in the phosphates from meteorites Los Angeles, Zagami, QUE94201 and ALH84001 predict isotopically light martian magmatic C, heavier than previous estimates yet significantly lighter than the terrestrial value.

  12. Paleomagnetic record of Martian meteorite ALH84001

    NASA Astrophysics Data System (ADS)

    Antretter, Maria; Fuller, Mike; Scott, Edward; Jackson, Mike; Moskowitz, Bruce; Solheid, Peter

    2003-06-01

    The natural remanent magnetization (NRM) of the Martian meteorite ALH84001 is predominantly carried by fine magnetite, which is found in association with carbonate. The magnetite is in epitaxial and topotactic relation with the carbonate and formed from the carbonate in the major impact event at 4.0 Ga. The NRM will therefore record this field. The local preferential crystallographic and shape alignment of the magnetite defines local easy directions of magnetization may account for the observed inhomogeneity of the NRM on a microscopic scale. Normalizing the intensity of the NRM by the saturation isothermal remanence (IRMs) then gives an estimate for the 4.0 Ga Martian field one order smaller than the present geomagnetic field. Such a field is unlikely to be strong enough to generate the high-intensity Martian magnetic anomalies. ALH 84001 in its pristine state as an orthopyroxenite is not a plausible source rock for the Martian anomalies because its magnetite was not formed until the 4.0 Ga event.

  13. SOM Classification of Martian TES Data

    NASA Technical Reports Server (NTRS)

    Hogan, R. C.; Roush, T. L.

    2002-01-01

    A classification scheme based on unsupervised self-organizing maps (SOM) is described. Results from its application to the ASU mineral spectral database are presented. Applications to the Martian Thermal Emission Spectrometer data are discussed. Additional information is contained in the original extended abstract.

  14. Radiative habitable zones in martian polar environments.

    PubMed

    Córdoba-Jabonero, Carmen; Zorzano, María-Paz; Selsis, Franck; Patel, Manish R; Cockell, Charles S

    2005-06-01

    The biologically damaging solar ultraviolet (UV) radiation (quantified by the DNA-weighted dose) reaches the martian surface in extremely high levels. Searching for potentially habitable UV-protected environments on Mars, we considered the polar ice caps that consist of a seasonally varying CO2 ice cover and a permanent H2O ice layer. It was found that, though the CO2 ice is insufficient by itself to screen the UV radiation, at approximately 1 m depth within the perennial H2O ice the DNA-weighted dose is reduced to terrestrial levels. This depth depends strongly on the optical properties of the H2O ice layers (for instance snow-like layers). The Earth-like DNA-weighted dose and Photosynthetically Active Radiation (PAR) requirements were used to define the upper and lower limits of the northern and southern polar Radiative Habitable Zone (RHZ) for which a temporal and spatial mapping was performed. Based on these studies we conclude that photosynthetic life might be possible within the ice layers of the polar regions. The thickness varies along each martian polar spring and summer between approximately 1.5 and 2.4 m for H2O ice-like layers, and a few centimeters for snow-like covers. These martian Earth-like radiative habitable environments may be primary targets for future martian astrobiological missions. Special attention should be paid to planetary protection, since the polar RHZ may also be subject to terrestrial contamination by probes.

  15. Meteoric Magnesium Ions in the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Pesnell, William Dean; Grebowsky, Joseph

    1999-01-01

    From a thorough modeling of the altitude profile of meteoritic ionization in the Martian atmosphere we deduce that a persistent layer of magnesium ions should exist around an altitude of 70 km. Based on current estimates of the meteoroid mass flux density, a peak ion density of about 10(exp 4) ions/cm is predicted. Allowing for the uncertainties in all of the model parameters, this value is probably within an order of magnitude of the correct density. Of these parameters, the peak density is most sensitive to the meteoroid mass flux density which directly determines the ablated line density into a source function for Mg. Unlike the terrestrial case, where the metallic ion production is dominated by charge-exchange of the deposited neutral Mg with the ambient ions, Mg+ in the Martian atmosphere is produced predominantly by photoionization. The low ultraviolet absorption of the Martian atmosphere makes Mars an excellent laboratory in which to study meteoric ablation. Resonance lines not seen in the spectra of terrestrial meteors may be visible to a surface observatory in the Martian highlands.

  16. Water retention of selected microorganisms and Martian soil simulants under close to Martian environmental conditions

    NASA Astrophysics Data System (ADS)

    Jänchen, J.; Bauermeister, A.; Feyh, N.; de Vera, J.-P.; Rettberg, P.; Flemming, H.-C.; Szewzyk, U.

    2014-08-01

    Based on the latest knowledge about microorganisms resistant towards extreme conditions on Earth and results of new complex models on the development of the Martian atmosphere we quantitatively examined the water-bearing properties of selected extremophiles and simulated Martian regolith components and their interaction with water vapor under close to Martian environmental conditions. Three different species of microorganisms have been chosen and prepared for our study: Deinococcus geothermalis, Leptothrix sp. OT_B_406, and Xanthoria elegans. Further, two mineral mixtures representing the early and the late Martian surface as well as montmorillonite as a single component of phyllosilicatic minerals, typical for the Noachian period on Mars, were selected. The thermal mass loss of the minerals and bacteria-samples was measured by thermoanalysis. The hydration and dehydration properties were determined under close to Martian environmental conditions by sorption isotherm measurements using a McBain-Bakr quartz spring balance. It was possible to determine the total water content of the materials as well as the reversibly bound water fraction as function of the atmospheres humidity by means of these methods. Our results are important for the evaluation of future space mission outcomes including astrobiological aspects and can support the modeling of the atmosphere/surface interaction by showing the influence on the water inventory of the upper most layer of the Martian surface.

  17. Prospects for Chronological Studies of Martian Rocks and Soils

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Shih, C-Y.; Reese, Y. D.

    2008-01-01

    Chronological information about Martian processes comes from two sources: Crater-frequency studies and laboratory studies of Martian meteorites. Each has limitations that could be overcome by studies of returned Martian rocks and soils. Chronology of Martian volcanism: The currently accepted chronology of Martian volcanic surfaces relies on crater counts for different Martian stratigraphic units [1]. However, there is a large inherent uncertainty for intermediate ages near 2 Ga ago. The effect of differing preferences for Martian cratering chronologies [1] is shown in Fig. 1. Stoeffler and Ryder [2] summarized lunar chronology, upon which Martian cratering chronology is based. Fig. 2 shows a curve fit to their data, and compares to it a corresponding lunar curve from [3]. The radiometric ages of some lunar and Martian meteorites as well as the crater-count delimiters for Martian epochs [4] also are shown for comparison to the craterfrequency curves. Scaling the Stoeffler-Ryder curve by a Mars/Moon factor of 1.55 [5] places Martian shergottite ages into the Early Amazonian to late Hesperian epochs, whereas using the lunar curve of [3] and a Mars/Moon factor 1 consigns the shergottites to the Middle-to-Late Amazonian, a less probable result. The problem is worsened if a continually decreasing cratering rate since 3 Ga ago is accepted [6]. We prefer the adjusted St ffler-Ryder curve because it gives better agreement with the meteorite ages (Fig.

  18. Workshop on Evolution of Martian Volatiles. Part 1

    NASA Technical Reports Server (NTRS)

    Jakosky, B. (Editor); Treiman, A. (Editor)

    1996-01-01

    This volume contains papers that were presented on February 12-14, 1996 at the Evolution for Martian Volatiles Workshop. Topics in this volume include: returned Martian samples; acidic volatiles and the Mars soil; solar EUV Radiation; the ancient Mars Thermosphere; primitive methane atmospheres on Earth and Mars; the evolution of Martian water; the role of SO2 for the climate history of Mars; impact crater morphology; the formation of the Martian drainage system; atmospheric dust-water ice Interactions; volatiles and volcanos; accretion of interplanetary dust particles; Mars' ionosphere; simulations with the NASA Ames Mars General Circulation Model; modeling the Martian water cycle; the evolution of Martian atmosphere; isotopic composition; solar occultation; magnetic fields; photochemical weathering; NASA's Mars Surveyor Program; iron formations; measurements of Martian atmospheric water vapor; and the thermal evolution Models of Mars.

  19. Mars Express Scientific Overview After One Martian Year in Orbit

    NASA Astrophysics Data System (ADS)

    Chicarro, A. F.

    2005-12-01

    The ESA Mars Express mission was successfully launched on 02 June 2003 from Baikonur, Kazakh-stan, onboard a Russian Soyuz rocket with a Fregat upper stage. The mission comprises an orbiter space-craft, which has been placed in a polar martian orbit, and the small Beagle-2 lander, due to land in Isidis Planitia but whose fate remains unknown. In addition to global studies of the surface, subsurface and at-mosphere of Mars, with an unprecedented spatial and spectral resolution, the unifying theme of the mis-sion is the search for water in its various states everywhere on the planet. Following the Mars Express spacecraft commissioning in January 2004, most experiments onboard be-gan their own calibration and testing phase already acquiring scientific data. This phase lasted until June 2004 when all the instruments started their routine operations. The MARSIS radar antennas, however, were deployed in May-June 2005, following comprehensive simulations of boom deployment and mitiga-tion of potential risks, to benefit from nightime conditions required for subsurface sounding before the pericentre natural drift in latitude, when illumination conditions become favourable to the other instru-ments. Initial science results are summarised below. The High-Resolution Stereo Colour Imager (HRSC) has shown breathtaking views of the planet, in particular of karstic regions near the Valles Marineris canyon (pointing to liquid water as the erosional agent responsible for modifying tectonic and impact features in the area) and of several large volcanoes (Olympus Mons caldera and glaciation features surrounding Hecates Tholus). The IR Mineralogical Mapping Spectrometer (OMEGA) has provided unprecedented maps of water ice and CO2 ice occurrence in the South pole, showing where the two ices mix and where they do not. The Planetary Fourier Spec-trometer (PFS) has confirmed the presence of methane for the first time, which would indicate current volcanic activity and/or biological

  20. Nature of Reduced Carbon in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K., Jr.; McKay, D. S.; Thomas-Keprta, K. L.; Clemett, S. J.; White, L. M.

    2012-01-01

    Martian meteorites provide important information on the nature of reduced carbon components present on Mars throughout its history. The first in situ analyses for carbon on the surface of Mars by the Viking landers yielded disappointing results. With the recognition of Martian meteorites on Earth, investigations have shown carbon-bearing phases exist on Mars. Studies have yielded presence of reduced carbon, carbonates and inferred graphitic carbon phases. Samples ranging in age from the first approximately 4 Ga of Mars history [e.g. ALH84001] to nakhlites with a crystallization age of 1.3 Ga [e.g. Nakhla] with aqueous alteration processes occurring 0.5-0.7 Ga after crystallizaton. Shergottites demonstrate formation ages around 165-500 Ma with younger aqueous alterations events. Only a limited number of the Martian meteorites do not show evidence of significance terrestrial alterations. Selected areas within ALH84001, Nakhla, Yamato 000593 and possibly Tissint are suitable for study of their indigenous reduced carbon bearing phases. Nakhla possesses discrete, well-defined carbonaceous phases present within iddingsite alteration zones. Based upon both isotopic measurements and analysis of Nakhla's organic phases the presence of pre-terrestrial organics is now recognized. The reduced carbon-bearing phases appear to have been deposited during preterrestrial aqueous alteration events that produced clays. In addition, the microcrystalline layers of Nakhla's iddingsite have discrete units of salt crystals suggestive of evaporation processes. While we can only speculate on the origin of these unique carbonaceous structures, we note that the significance of such observations is that it may allow us to understand the role of Martian carbon as seen in the Martian meteorites with obvious implications for astrobiology and the pre-biotic evolution of Mars. In any case, our observations strongly suggest that reduced organic carbon exists as micrometer- size, discrete structures

  1. Preliminary design of a universal Martian lander

    NASA Astrophysics Data System (ADS)

    Norman, Timothy L.; Gaskin, David E.; Adkins, Sean; Gunawan, Mary; Johnson, Raquel; Macdonnell, David; Parlock, Andrew; Sarick, John; Bodwell, Charles; Hashimoto, Kouichi

    In the next 25 years, mankind will be undertaking yet another giant leap forward in the exploration of the solar system: a manned mission to Mars. This journey will provide important information on the composition and history of both Mars and the Solar System. A manned mission will also provide the opportunity to study how humans can adapt to long term space flight conditions and the Martian environment. As part of the NASA/USRA program, nineteen West Virginia University students conducted a preliminary design of a manned Universal Martian Lander (UML). The UML's design will provide a 'universal' platform, consisting of four modules for living and laboratory experiments and a liquid-fuel propelled Manned Ascent Return Vehicle (MARV). The distinguishing feature of the UML is the 'universal' design of the modules which can be connected to form a network of laboratories and living quarters for future missions thereby reducing development and production costs. The WVU design considers descent to Mars from polar orbit, a six month surface stay, and ascent for rendezvous. The design begins with an unmanned UML landing at Elysium Mons followed by the manned UML landing nearby. During the six month surface stay, the eight modules will be assembled to form a Martian base where scientific experiments will be performed. The mission will also incorporate hydroponic plant growth into a Controlled Ecological Life Support System (CELSS) for water recycling, food production, and to counteract psychological effects of living on Mars. In situ fuel production for the MARV will be produced from gases in the Martian atmosphere. Following surface operations, the eight member crew will use the MARV to return to the Martian Transfer Vehicle (MTV) for the journey home to Earth.

  2. Characteristics of the Martian atmosphere surface layer

    NASA Astrophysics Data System (ADS)

    Clow, G. D.; Haberle, R. M.

    Elements of various terrestrial boundary layer models are extended to Mars in order to estimate sensible heat, latent heat, and momentum fluxes within the Martian atmospheric surface ('constant flux') layer. The atmospheric surface layer consists of an interfacial sublayer immediately adjacent to the ground and an overlying fully turbulent surface sublayer where wind-shear production of turbulence dominates buoyancy production. Within the interfacial sublayer, sensible and latent heat are transported by non-steady molecular diffusion into small-scale eddies which intermittently burst through this zone. Both the thickness of the interfacial sublayer and the characteristics of the turbulent eddies penetrating through it depend on whether airflow is aerodynamically smooth or aerodynamically rough, as determined by the Roughness Reynold's number. Within the overlying surface sublayer, similarity theory can be used to express the mean vertical windspeed, temperature, and water vapor profiles in terms of a single parameter, the Monin-Obukhov stability parameter. To estimate the molecular viscosity and thermal conductivity of a CO2-H2O gas mixture under Martian conditions, parameterizations were developed using data from the TPRC Data Series and the first-order Chapman-Cowling expressions; the required collision integrals were approximated using the Lenard-Jones potential. Parameterizations for specific heat and binary diffusivity were also determined. The Brutsart model for sensible and latent heat transport within the interfacial sublayer for both aerodynamically smooth and rough airflow was experimentally tested under similar conditions, validating its application to Martian conditions. For the surface sublayer, the definition of the Monin-Obukhov length was modified to properly account for the buoyancy forces arising from water vapor gradients in the Martian atmospheric boundary layer. It was found that under most Martian conditions, the interfacial and surface

  3. Preliminary design of a universal Martian lander

    NASA Technical Reports Server (NTRS)

    Norman, Timothy L.; Gaskin, David E.; Adkins, Sean; Gunawan, Mary; Johnson, Raquel; Macdonnell, David; Parlock, Andrew; Sarick, John; Bodwell, Charles; Hashimoto, Kouichi

    1993-01-01

    In the next 25 years, mankind will be undertaking yet another giant leap forward in the exploration of the solar system: a manned mission to Mars. This journey will provide important information on the composition and history of both Mars and the Solar System. A manned mission will also provide the opportunity to study how humans can adapt to long term space flight conditions and the Martian environment. As part of the NASA/USRA program, nineteen West Virginia University students conducted a preliminary design of a manned Universal Martian Lander (UML). The UML's design will provide a 'universal' platform, consisting of four modules for living and laboratory experiments and a liquid-fuel propelled Manned Ascent Return Vehicle (MARV). The distinguishing feature of the UML is the 'universal' design of the modules which can be connected to form a network of laboratories and living quarters for future missions thereby reducing development and production costs. The WVU design considers descent to Mars from polar orbit, a six month surface stay, and ascent for rendezvous. The design begins with an unmanned UML landing at Elysium Mons followed by the manned UML landing nearby. During the six month surface stay, the eight modules will be assembled to form a Martian base where scientific experiments will be performed. The mission will also incorporate hydroponic plant growth into a Controlled Ecological Life Support System (CELSS) for water recycling, food production, and to counteract psychological effects of living on Mars. In situ fuel production for the MARV will be produced from gases in the Martian atmosphere. Following surface operations, the eight member crew will use the MARV to return to the Martian Transfer Vehicle (MTV) for the journey home to Earth.

  4. Martian Mixed Layer during Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    Martinez, G. M.; Valero, F.; Vazquez, L.

    2008-09-01

    In situ measurements of the Martian Planetary Boundary Layer (MPBL) encompass only the sur- face layer. Therefore, in order to fully address the MPBL, it becomes necessary to simulate somehow the behaviour of the martian mixed layer. The small-scale processes that happen in the MPBL cause GCM's ([1], [2]) to describe only partially the turbulent statistics, height, convective scales, etc, of the surface layer and the mixed layer. For this reason, 2D and 3D martian mesoscale models ([4], [5]), and large eddy simulations ([4], [6], [7], [8]) have been designed in the last years. Although they are expected to simulate more accurately the MPBL, they take an extremely expensive compu- tational time. Alternatively, we have derived the main turbu- lent characteristics of the martian mixed layer by using surface layer and mixed layer similarity ([9], [10]). From in situ temperature and wind speed measurements, together with quality-tested simu- lated ground temperature [11], we have character- ized the martian mixed layer during the convective hours of Pathfinder mission Sol 25. Mean mixed layer turbulent statistics like tem- perature variance < σ? >, horizontal wind speed variance < σu,v >, vertical wind speed variance < σw >, viscous dissipation rate < ǫ >, and turbu- lent kinetic energy < e > have been calculated, as well as the mixed layer height zi, and the convective scales of wind w? and temperature θ?. Our values, obtained with negligible time cost, match quite well with some previously obtained results via LES's ([4] and [8]). A comparisson between the above obtained mar- tian values and the typical Earth values are shown in Table 1. Convective velocity scale w doubles its counterpart terrestrial typical value, as it does the mean wind speed variances < σu,v > and < σw >. On the other hand, the temperature scale θ? and the mean temperature variance < σ > are virtually around one order higher on Mars. The limitations of these results concern the va- lidity

  5. High resolution Viking Orbiter images: A useful data source for testing the viability of geomorphic processes attributed to Martian landforms

    NASA Technical Reports Server (NTRS)

    Zimbelman, James R.

    1987-01-01

    The diversity of landforms visible in the Viking images of Mars have led to a proliforation of geomorphic agents proposed to be active in shaping the Martian surface. While it is likely that numerous different processes have contributed to the geomorphology of Mars throughout Martian history, it is important that proposed Martian geomorphic agents be subjected to critical scrutiny by the scientific community. High resolution Viking Orbiter images represent a data set for investigating geomorphic processes on Mars. Geologic mapping of Mars can take place at a variety of scales, utilizing a variety of image resolutions, but an interpretation of the history of individual landforms is dependent upon the best available spatial resolution. These high resolution images provide the opportunity to examine proposed Martian geomorphic processes. It is clear that researchers may not interpret features in the same way but it is important that high resolution images of candidate features be made available to the scientific community so that a consensus can be reached. This procedure can provide a way to refine the understanding of geomorphic processes on Mars.

  6. The potential of hydrodynamic analysis for the interpretation of Martian fluvial activities

    NASA Astrophysics Data System (ADS)

    Kim, Jungrack; Schumann, Guy; Neal, Jeffrey; Lin, Shih-Yuan

    2014-05-01

    After liquid water was identified as the agent of ancient Martian fluvial activities, the valley and channels on the Martian surface were investigated by a number of remote sensing and in-situ measurements. In particular, the stereo DTMs and ortho images from various successful orbital sensors are being effectively used to trace the origin and consequences of Martian hydrological channels. For instance, to analyze the Martian fluvial activities more quantitatively using the topographic products, Burr et al. (2003) employed 1D hydrodynamic models such as HEC-RAS together with the topography by MOLA to derive water flow estimates for the Athabasca Valles area on Mars [1]. Where extensive floodplain flows or detailed 2D bathymetry for the river channel exist, it may be more accurate to simulate flows in two dimensions, especially if the direction of flow is unclear a priori. Thus in this study we demonstrated a quantitative modeling method utilizing multi-resolution Martian DTMs, constructed in line with Kim and Muller's (2009) [2] approach, and an advanced hydraulics model LISFLOOD-FP (Bates et al., 2010) [3], which simulates in-channel dynamic wave behavior by solving for 2D shallow water equations without advection. Martian gravitation and manning constants were adjusted in the hydraulic model and the inflow values were iteratively refined from the outputs of the coarser to the finer model. Then we chose the target areas among Martian fluvial geomorphologies and tested the effectiveness of high resolution hydraulic modeling to retrieve the characteristics of fluvial systems. Test sites were established in the Athabasca Valles, Bahram Vallis, and Naktong Vallis respectively. Since those sites are proposed to be originated by different fluvial mechanisms, it is expected that the outputs from hydraulics modeling will provide important clues about the evolution of each fluvial system. Hydraulics modeling in the test areas with terrestrial simulation parameters was also

  7. Chemical Weathering Records of Martian Soils Preserved in the Martian Meteorite EET79001

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Wentworth, S. J.; McKay, D. S.

    2004-01-01

    Impact-melt glasses, rich in Martian atmospheric gases, contain Martian soil fines (MSF) mixed with other coarse-grained regolith fractions which are produced during impact bombardment on Mars surface. An important characteristic of the MSF fraction is the simultaneous enrichment of felsic component accompanied by the depletion of mafic component relative to the host phase in these glasses. In addition, these glasses yield large sulfur abundances due to the occurrence of secondary mineral phases such as sulfates produced during acid-sulfate weathering of the regolith material near the Martian surface. Sulfurous gases released into atmosphere by volcanoes on Mars are oxidized to H2SO4 which deposit back on the surface of Mars as aerosol particles. Depending on the water availability, sulfuric acids dissolve into solutions which aggressively decompose the Fe-Mg silicates in the Martian regolith. During chemical weathering, structural elements such as Fe, Mg and Ca (among others) are released into the transgressing solutions. These solutions leach away the soluble components of Mg, Ca and Na, leaving behind insoluble iron as Fe3(+) hydroxysulfate mixed with poorly crystalline hydroxide- precipitates under oxidizing conditions. In this study, we focus on the elemental distribution of FeO and SO3 in the glass veins of EET79001, 507 sample, determined by Electron Microprobe and FE SEM measurements at JSC. This glass sample is an aliquot of a bigger glass inclusion ,104 analysed by where large concentrations of Martian atmospheric noble gases are found.

  8. Overview of the Martian radiation environment experiment.

    PubMed

    Zeitlin, C; Cleghorn, T; Cucinotta, F; Saganti, P; Andersen, V; Lee, K; Pinsky, L; Atwell, W; Turner, R; Badhwar, G

    2004-01-01

    Space radiation presents a hazard to astronauts, particularly those journeying outside the protective influence of the geomagnetosphere. Crews on future missions to Mars will be exposed to the harsh radiation environment of deep space during the transit between Earth and Mars. Once on Mars, they will encounter radiation that is only slightly reduced, compared to free space, by the thin Martian atmosphere. NASA is obliged to minimize, where possible, the radiation exposures received by astronauts. Thus, as a precursor to eventual human exploration, it is necessary to measure the Martian radiation environment in detail. The MARIE experiment, aboard the 2001 Mars Odyssey spacecraft, is returning the first data that bear directly on this problem. Here we provide an overview of the experiment, including introductory material on space radiation and radiation dosimetry, a description of the detector, model predictions of the radiation environment at Mars, and preliminary dose-rate data obtained at Mars.

  9. CO2 Impacts on the Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Kelley, Michael; Bauer, James; Bodewits, Dennis; Farnham, Tony; Stevenson, Rachel; Yelle, Roger

    2014-09-01

    The dynamically new comet C/2013 A1 (Siding Spring) will pass Mars at the extremely close distance of 140,000 km on 2014 Oct 19. This encounter is unique---a record close approach to a planet with spacecraft that can observe its passage---and currently, all 5 Mars orbiters have plans to observe the comet and/or its effects on the planet. Gas from the comet's coma is expected to collide with the Martian atmosphere, altering the abundances of some species and producing significant heating, inflating the upper atmosphere. We propose DDT observations with Spitzer/IRAC to measure the comet's CO2+CO coma (observing window Oct 30 - Nov 20), to use these measurements to derive the coma's CO2 density at Mars during the closest approach, and to aid the interpretation of any observed effects or changes in the Martian atmosphere.

  10. Ice sculpture in the Martian outflow channels

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1982-01-01

    Viking Orbiter and terrestrial satellite images are examined at similar resolution to compare features of the Martian outflow channels with features produced by the movement of ice on earth, and many resemblances are found. These include the anastomoses, sinuosities, and U-shaped cross profiles of valleys; hanging valleys; linear scour marks on valley walls; grooves and ridges on valley floors; and the streamlining of bedrock highs. Attention is given to the question whether ice could have moved in the Martian environment. It is envisaged that springs or small catastrophic outbursts discharged fluids from structural outlets or chaotic terrains. These fluids built icings that may have grown into substantial masses and eventually flowed like glaciers down preexisting valleys. An alternative is that the fluids formed rivers or floods that in turn formed ice jams and consolidated into icy masses in places where obstacles blocked their flow.

  11. Dust transport into Martian polar latitudes

    NASA Technical Reports Server (NTRS)

    Murphy, J. R.; Pollack, J. B.

    1992-01-01

    The presence of suspended dust in the Martian atmosphere, and its return to the planet's surface, is implicated in the formation of the polar layered terrain and the dichotomy in perennial CO2 polar cap retention in the two hemispheres. A three dimensional model was used to study Martian global dust storms. The model accounts for the interactive feedbacks between the atmospheric thermal and dynamical states and an evolving radiatively active suspended dust load. Results from dust storm experiments, as well as from simulations in which there is interest in identifying the conditions under which surface dust lifting occurs at various locations and times, indicate that dust transport due to atmospheric eddy motions is likely to be important in the arrival of suspended dust at polar latitudes. The layered terrain in both polar regions of Mars is interpreted as the reality of cyclical episodes of volatile (CO2, H2O) and dust deposition.

  12. Exploration of Martian Surface using Autonomous Octocopter

    NASA Astrophysics Data System (ADS)

    Shah, K.

    2015-10-01

    To make an Octocopter that will land with the rover that will be deployed in 2018/20. This Octocopter will carry a set of instruments and will hover upto a certain height of 20-65m or more. 1) The main aim of the Octocopter is the analysis of the Martian atmosphere for the presence of methane or other gases and its composition.2) It will also help the rover by delivering it samples of the Martian soil. Ex:- Suppose right now this Octocopter is present on mars it can help the curiosity rover by directly taking samples of soil in Mount sharp base and deliver it to the rover. 3) It can act as an orbiter that will send HD images back on Earth. This Octocopter can also help in investigation of Mars moon's - Phobos and Deimos. It can also be used for studying and going deep down in the atmosphere of Titan and Enceladeus.

  13. The Martian dust cycle: A proposed model

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald

    1987-01-01

    Despite more than a decade of study of martian dust storms, many of their characteristics and associated processes remain enigmatic, including the mechanisms for dust raising, modes of settling, and the nature of dust deposits. However, observations of Mars dust, considerations of terrestrial analogs, theoretical models, and laboratory simulations permit the formulation of a Martian Dust Cycle Model, which consists of three main processes: (1) suspension threshold, (2) transportation, and (3) deposition; two associated processes are also included: (4) dust removal and (5) the addition of new dust to the cycle. Although definitions vary, dust includes particles less than 4 to approx. 60 microns in diameter, which by terrestrial usage includes silt, loess, clay, and aerosolic dust particles. The dust cycle model is explained.

  14. Martian Dust Collected by Phoenix's Arm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image from NASA's Phoenix Lander's Optical Microscope shows particles of Martian dust lying on the microscope's silicon substrate. The Robotic Arm sprinkled a sample of the soil from the Snow White trench onto the microscope on July 2, 2008, the 38th Martian day, or sol, of the mission after landing.

    Subsequently, the Atomic Force Microscope, or AFM, zoomed in one of the fine particles, creating the first-ever image of a particle of Mars' ubiquitous fine dust, the most highly magnified image ever seen from another world.

    The Atomic Force Microscope was developed by a Swiss-led consortium in collaboration with Imperial College London. The AFM is part of Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer instrument.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. Overview of the Martian radiation environment experiment.

    PubMed

    Zeitlin, C; Cleghorn, T; Cucinotta, F; Saganti, P; Andersen, V; Lee, K; Pinsky, L; Atwell, W; Turner, R; Badhwar, G

    2004-01-01

    Space radiation presents a hazard to astronauts, particularly those journeying outside the protective influence of the geomagnetosphere. Crews on future missions to Mars will be exposed to the harsh radiation environment of deep space during the transit between Earth and Mars. Once on Mars, they will encounter radiation that is only slightly reduced, compared to free space, by the thin Martian atmosphere. NASA is obliged to minimize, where possible, the radiation exposures received by astronauts. Thus, as a precursor to eventual human exploration, it is necessary to measure the Martian radiation environment in detail. The MARIE experiment, aboard the 2001 Mars Odyssey spacecraft, is returning the first data that bear directly on this problem. Here we provide an overview of the experiment, including introductory material on space radiation and radiation dosimetry, a description of the detector, model predictions of the radiation environment at Mars, and preliminary dose-rate data obtained at Mars. PMID:15791732

  16. Martian magnetic anomalies and ionosphere escape rate.

    NASA Astrophysics Data System (ADS)

    Fedorov, A.; Barabash, S.; Sauvaud, J.-A.

    2012-04-01

    Looking forward to the MAVEN mission, it seems very useful to return to Mars Express data to refresh an important problem of Martian atmosphere escape: what role the crustal magnetic field may play in this process? There are several publications on this topic with completely opposite conclusions. The last hybrid simulations show that the magnetic anomalies significantly reduce the ion loss rate during solar minimum. We are trying to use a new approach to Mars Express IMA data analysis to check how it is possible.On the base of a statistical study of the ion distributions in the Martian magnetotail we show that the characteristic accelerated ions are not associated with the magnetic anomalies but only with interplanetary magnetic field clock angle. Moreover the magnetic anomalies screen and deviate the escaping flow leading to reducing of the total loss rate. Finally the observed heavy ions escaping rate is in a fantastic agreement with simulation results.

  17. Nuclear rocket using indigenous Martian fuel NIMF

    NASA Technical Reports Server (NTRS)

    Zubrin, Robert

    1991-01-01

    In the 1960's, Nuclear Thermal Rocket (NTR) engines were developed and ground tested capable of yielding isp of up to 900 s at thrusts up to 250 klb. Numerous trade studies have shown that such traditional hydrogen fueled NTR engines can reduce the inertial mass low earth orbit (IMLEO) of lunar missions by 35 percent and Mars missions by 50 to 65 percent. The same personnel and facilities used to revive the hydrogen NTR can also be used to develop NTR engines capable of using indigenous Martian volatiles as propellant. By putting this capacity of the NTR to work in a Mars descent/acent vehicle, the Nuclear rocket using Indigenous Martian Fuel (NIMF) can greatly reduce the IMLEO of a manned Mars mission, while giving the mission unlimited planetwide mobility.

  18. Overview of the Martian radiation environment experiment

    SciTech Connect

    Zeitlin, C.; Cleghorn, T.F.; Cucinotta, F.A.; Saganti, P.; Andersen, V.; Lee, K.T.; Pinsky, L.S.; Atwell, W.; Turner, R.; Badhwar, G.

    2004-12-01

    Space radiation presents a hazard to astronauts, particularly those journeying outside the protective influence of the geomagnetosphere. Crews on future missions to Mars will be exposed to the harsh radiation environment of deep space during the transit between Earth and Mars. Once on Mars, they will encounter radiation that is only slightly reduced, compared to free space, by the thin Martian atmosphere. NASA is obliged to minimize, where possible, the radiation exposures received by astronauts. Thus, as a precursor to eventual human exploration, it is necessary to measure the Martian radiation environment in detail. The MARIE experiment, aboard the 2001 Mars Odyssey spacecraft, is returning the first data that bear directly on this problem. Here we provide an overview of the experiment, including introductory material on space radiation and radiation dosimetry, a description of the detector, model predictions of the radiation environment at Mars, and preliminary dose-rate data obtained at Mars.

  19. The economics of mining the Martian moons

    NASA Technical Reports Server (NTRS)

    Leonard, Raymond S.; Blacic, James D.; Vaniman, David T.

    1987-01-01

    The costs for extracting and shipping volatiles such as water, carbon, and nitrogen that might be found on Phobos and Deimos are estimated. The costs are compared to the cost of shipping the same volatiles from earth, assuming the use of nuclear powered mining facilities and freighters. Mineral resources and possible products from the Martian moons, possible markets for these products, and the costs of transporting these resources to LEO or GEO or to transportation nodal points are examined. Most of the technology needed to mine the moons has already been developed. The need for extraterrestrial sources of propellants for ion propulsion systems and ways in which the mining of the moons would reduce the cost of space operations near earth are discussed. It is concluded that it would be commercially viable to mine the Martian moons, making a profit of at least a 10 percent return on capital.

  20. Squeezing Meteorites to Reveal the Martian Mantle

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2006-12-01

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

  1. Viking Biology Experiments and the Martian soil

    NASA Technical Reports Server (NTRS)

    Banin, Amos

    1989-01-01

    The Viking Biology Experiments (VBE) are the most informative database on the wet chemistry and reactivity of the Martian soil available today. The simulation and chemical interpretation of the results have given valuable hints towards the characterization of the soils' mineralogy, adsorption properties, pH and redox. The characterization of Mars' soil on the basis of ten years of labelled release (LR) and other VBE simulations are reviewed.

  2. A thermal model of the Martian satellites

    SciTech Connect

    Kuehrt, E.; Giese, B. )

    1989-09-01

    A thermal model for Phobos and Deimos is proposed as the basis for interpreting radiometric data of the Martian satellites. The model includes effects such as reflected and thermal radiation of Mars, ellipsoidal shape, and the strong temperature dependence of the heat conduction coefficient. Model results are presented for the diurnal temperature behavior for various latitudes and longitudes to demonstrate the impact of these effects in the thermal characteristics of Phobos and Deimos. 15 refs.

  3. Martian relief and the coming opposition.

    PubMed

    Harris, D H

    1967-06-16

    In the report "Martian relief and the coming opposition" (3 Mar., p. 1100), D. H. Harris stated that, "... the reduced contrast with decreasing (terminator distance) just balances the increase in visibility due to shadow length." This is obviously erroneous. A more careful examination of the problem shows that for favorable values of the Aerocentric EarthSun Sun angle, visibility of relief increases toward the terminator, clouds not withstanding.

  4. Permeability Barrier Generation in the Martian Lithosphere

    NASA Astrophysics Data System (ADS)

    Schools, Joe; Montési, Laurent

    2015-11-01

    Permeability barriers develop when a magma produced in the interior of a planet rises into the cooler lithosphere and crystallizes more rapidly than the lithosphere can deform (Sparks and Parmentier, 1991). Crystallization products may then clog the porous network in which melt is propagating, reducing the permeability to almost zero, i.e., forming a permeability barrier. Subsequent melts cannot cross the barrier. Permeability barriers have been useful to explain variations in crustal thickness at mid-ocean ridges on Earth (Magde et al., 1997; Hebert and Montési, 2011; Montési et al., 2011). We explore here under what conditions permeability barriers may form on Mars.We use the MELTS thermodynamic calculator (Ghiorso and Sack, 1995; Ghiorso et al., 2002; Asimow et al., 2004) in conjunction with estimated Martian mantle compositions (Morgan and Anders, 1979; Wänke and Dreibus, 1994; Lodders and Fegley, 1997; Sanloup et al., 1999; Taylor 2013) to model the formation of permeability barriers in the lithosphere of Mars. In order to represent potential past and present conditions of Mars, we vary the lithospheric thickness, mantle potential temperature (heat flux), oxygen fugacity, and water content.Our results show that permeability layers can develop in the thermal boundary layer of the simulated Martian lithosphere if the mantle potential temperature is higher than ~1500°C. The various Martian mantle compositions yield barriers in the same locations, under matching variable conditions. There is no significant difference in barrier location over the range of accepted Martian oxygen fugacity values. Water content is the most significant influence on barrier development as it reduces the temperature of crystallization, allowing melt to rise further into the lithosphere. Our lower temperature and thicker lithosphere model runs, which are likely the most similar to modern Mars, show no permeability barrier generation. Losing the possibility of having a permeability

  5. The Martian atmosphere: some unanswered questions.

    PubMed

    Owen, T

    1979-12-01

    The study of the Martian atmosphere and its significance for the possible origin of life on Mars is still very incomplete. Further investigations are needed to define the total volatile inventory, the early history of the atmosphere, and the relationship of the atmosphere to the question of indigenous life. In addition, studies of Venus, comets, and the Jupiter system will add significantly to our abilities to understand the early history of Mars.

  6. A reduced organic carbon component in martian basalts.

    PubMed

    Steele, A; McCubbin, F M; Fries, M; Kater, L; Boctor, N Z; Fogel, M L; Conrad, P G; Glamoclija, M; Spencer, M; Morrow, A L; Hammond, M R; Zare, R N; Vicenzi, E P; Siljeström, S; Bowden, R; Herd, C D K; Mysen, B O; Shirey, S B; Amundsen, H E F; Treiman, A H; Bullock, E S; Jull, A J T

    2012-07-13

    The source and nature of carbon on Mars have been a subject of intense speculation. We report the results of confocal Raman imaging spectroscopy on 11 martian meteorites, spanning about 4.2 billion years of martian history. Ten of the meteorites contain abiotic macromolecular carbon (MMC) phases detected in association with small oxide grains included within high-temperature minerals. Polycyclic aromatic hydrocarbons were detected along with MMC phases in Dar al Gani 476. The association of organic carbon within magmatic minerals indicates that martian magmas favored precipitation of reduced carbon species during crystallization. The ubiquitous distribution of abiotic organic carbon in martian igneous rocks is important for understanding the martian carbon cycle and has implications for future missions to detect possible past martian life. PMID:22628557

  7. A reduced organic carbon component in martian basalts.

    PubMed

    Steele, A; McCubbin, F M; Fries, M; Kater, L; Boctor, N Z; Fogel, M L; Conrad, P G; Glamoclija, M; Spencer, M; Morrow, A L; Hammond, M R; Zare, R N; Vicenzi, E P; Siljeström, S; Bowden, R; Herd, C D K; Mysen, B O; Shirey, S B; Amundsen, H E F; Treiman, A H; Bullock, E S; Jull, A J T

    2012-07-13

    The source and nature of carbon on Mars have been a subject of intense speculation. We report the results of confocal Raman imaging spectroscopy on 11 martian meteorites, spanning about 4.2 billion years of martian history. Ten of the meteorites contain abiotic macromolecular carbon (MMC) phases detected in association with small oxide grains included within high-temperature minerals. Polycyclic aromatic hydrocarbons were detected along with MMC phases in Dar al Gani 476. The association of organic carbon within magmatic minerals indicates that martian magmas favored precipitation of reduced carbon species during crystallization. The ubiquitous distribution of abiotic organic carbon in martian igneous rocks is important for understanding the martian carbon cycle and has implications for future missions to detect possible past martian life.

  8. Martian regolith geochemistry and sampling techniques

    NASA Technical Reports Server (NTRS)

    Clark, B. C.

    1988-01-01

    Laboratory study of samples of the intermediate and fine-grained regolith, including duricrust peds, is a fundamental prerequisite for understanding the types of physical and chemical weathering processes on Mars. The extraordinary importance of such samples is their relevance to understanding past changes in climate, availability (and possible physical state) of water, eolian forces, the thermal and chemical influences of volcanic and impact processes, and the inventory and fates of Martian volatiles. Fortunately, this regolith material appears to be ubiquitous over the Martian surface, and should be available at many different landing sites. Viking data has been interpreted to indicate a smectite-rich regolith material, implying extensive weathering involving aqueous activity and geochemical alteration. An all-igneous source of the Martian fines has also been proposed. The X-ray fluorescence measurement data set can now be fully explained in terms of a simple two-component model. The first component is silicate, having strong geochemical similarities with Shergottites, but not other SNC meteorites. The second component is salt. Variations in these components could produce silicate and salt-rich beds, the latter being of high potential importance for microenvironments in which liquid water (brines) could exist. It therefore would be desirable to scan the surface of the regolith for such prospects.

  9. Launch of martian meteorites in oblique impacts

    NASA Astrophysics Data System (ADS)

    Artemieva, Natalia; Ivanov, Boris

    2004-09-01

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

  10. Ice Clouds in Martian Arctic (Accelerated Movie)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Clouds scoot across the Martian sky in a movie clip consisting of 10 frames taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander.

    This clip accelerates the motion. The camera took these 10 frames over a 10-minute period from 2:52 p.m. to 3:02 p.m. local solar time at the Phoenix site during Sol 94 (Aug. 29), the 94th Martian day since landing.

    Particles of water-ice make up these clouds, like ice-crystal cirrus clouds on Earth. Ice hazes have been common at the Phoenix site in recent days.

    The camera took these images as part of a campaign by the Phoenix team to see clouds and track winds. The view is toward slightly west of due south, so the clouds are moving westward or west-northwestward.

    The clouds are a dramatic visualization of the Martian water cycle. The water vapor comes off the north pole during the peak of summer. The northern-Mars summer has just passed its peak water-vapor abundance at the Phoenix site. The atmospheric water is available to form into clouds, fog and frost, such as the lander has been observing recently.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  11. Where to search for martian biota?

    NASA Astrophysics Data System (ADS)

    Tasch, Paul

    1997-07-01

    Martian Salt. Terrestrial halite containing negative crystals which entrapped drops of viscous fluid yielded viable bacteria. The fluid has a Br/Mg ratio which chemist W.T. Holser characterized as a `Permian bittern.' All relevant salt on Mars should be inspected for negative crystals and possible ancient bacterial tenants. Martian Water. Moist soil in the regolith, cooled hydrothermal fluids, sediments of recurrent oceanic water, and related to inferred strand lines, even limited water in future SNC-type meteorites, upper atmosphere liquid water or water vapor, and North Polar liquid water or ice--all liquid water in any form, wherever, should be collected for microbiological analysis. Vent Fauna. Living or fossil thermophiles as trace fossils, or fauna metallicized in relation to sulphide ores. Iron Bacteria. Limonitized magnetite ore (USSR) in thin section showed structures attributed to iron bacteria. Biogenic magnetite, produced by both aerobic and anaerobic bacteria and its significance. Carbonaceous chondrites (non martian) (Ivuna and Orgueil) yielded apparent life forms that could not be attributed to contamination during the given study. Are they extraterrestrial?

  12. Martian Atmospheric Pressure Static Charge Elimination Tool

    NASA Technical Reports Server (NTRS)

    Johansen, Michael R.

    2014-01-01

    A Martian pressure static charge elimination tool is currently in development in the Electrostatics and Surface Physics Laboratory (ESPL) at NASA's Kennedy Space Center. In standard Earth atmosphere conditions, static charge can be neutralized from an insulating surface using air ionizers. These air ionizers generate ions through corona breakdown. The Martian atmosphere is 7 Torr of mostly carbon dioxide, which makes it inherently difficult to use similar methods as those used for standard atmosphere static elimination tools. An initial prototype has been developed to show feasibility of static charge elimination at low pressure, using corona discharge. A needle point and thin wire loop are used as the corona generating electrodes. A photo of the test apparatus is shown below. Positive and negative high voltage pulses are sent to the needle point. This creates positive and negative ions that can be used for static charge neutralization. In a preliminary test, a floating metal plate was charged to approximately 600 volts under Martian atmospheric conditions. The static elimination tool was enabled and the voltage on the metal plate dropped rapidly to -100 volts. This test data is displayed below. Optimization is necessary to improve the electrostatic balance of the static elimination tool.

  13. Dust in the Martian Atmosphere: Polarimetric Sensing

    NASA Astrophysics Data System (ADS)

    Ebisawa, S.; Dollfus, A.

    1993-05-01

    Several thousands of determinations of the degree of linear polarization have been recorded over the disk of Planet Mars, at Tokyo Observatory station, from 1977 to 1991. In addition to the polarization produced by reflectance over the Martian soil surface, there is some perturbations by local veils of crystal or by dust storms which have been already analyzed. But a new type of unusual event has been discovered, displaying temporary anomalies in the degree of polarization. Their analysis characterizes faint and transparent veils, localized over specific areas, and at certain times of the Martian year corresponding to the maximum solar heating. The scattering theory of Mie indicates solid, absorbing sub-micron size grains, reminiscent of small dust particles raised from the soil surface. Dust is observed in the Martian atmosphere at three levels: (1) a permanent faint haze made of very small dust particles. (2) Temporary local transparent veils made of submicron size grains, preferentially during seasons and latitudes of maximum solar heating. (3) Occasionally, an evolution of these veils to produce extensive, dense, dust storms made of micron size grains, which may spread all over the planet for weeks.

  14. Variability in Martian magnetic field topology

    NASA Astrophysics Data System (ADS)

    Brain, D. A.; Halekas, J. S.; Eastwood, J. P.; Ulusen, D.; Lillis, R. J.

    2013-12-01

    Martian crustal magnetic fields form localized mini-magnetosphere structures that extend in some regions well above the Martian ionosphere, interacting directly with the draped external interplanetary magnetic field (IMF). In some regions the crustal magnetic field lines are closed, locally shielding the ionosphere from external plasma. In other locations the crustal field lines are open, allowing exchange of plasma between the ionosphere and the surrounding plasma interaction region. The average magnetic topology as a function of geographic location has been mapped previously, using ~7 years of Mars Global Surveyor electron observations recorded at constant altitude and local time. In this previous work, pitch angle distributions of suprathermal electrons were examined for the presence of loss cones to determine whether field lines were open or closed. Here we apply the same technique to describe how magnetic topology varies with four external drivers: solar wind pressure, IMF orientation, solar EUV flux, and Martian season. We see that some locations on Mars change topology frequently depending upon external conditions, while others have a relatively static field topology.

  15. Unusual Iron Redox Systematics of Martian Magmas

    SciTech Connect

    Danielson, L.; Righter, K.; Pando, K.; Morris, R.V.; Graff, T.; Agresti, D.; Martin, A.; Sutton, S.; Newville, M.; Lanzirotti, A.

    2012-03-26

    Martian magmas are known to be FeO-rich and the dominant FeO-bearing mineral at many sites visited by the Mars Exploration rovers (MER) is magnetite. Morris et al. proposed that the magnetite appears to be igneous in origin, rather than of secondary origin. However, magnetite is not typically found in experimental studies of martian magmatic rocks. Magnetite stability in terrestrial magmas is well understood, as are the stabilities of FeO and Fe{sub 2}O{sub 3} in terrestrial magmas. In order to better understand the variation of FeO and Fe{sub 2}O{sub 3}, and the stability of magnetite (and other FeO-bearing phases) in martian magmas, we have undertaken an experimental study with two emphases. First, we determine the FeO and Fe{sub 2}O{sub 3} contents of super- and sub-liquidus glasses from a shergottite bulk composition at 1 bar to 4 GPa, and variable fO{sub 2}. Second, we document the stability of magnetite with temperature and fO{sub 2} in a shergottite bulk composition.

  16. The Germanium Dichotomy in Martian Meteorites

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

  17. Unusual Iron Redox Systematics of Martian Magmas

    NASA Technical Reports Server (NTRS)

    Danielson, L.; Righter, K.; Pando, K.; Morris, R. V.; Graff, T.; Agresti, D.; Martin, A.; Sutton, S.; Newville, M.; Lanzirotti, A.

    2012-01-01

    Martian magmas are known to be FeO-rich and the dominant FeO-bearing mineral at many sites visited by the Mars Exploration rovers (MER) is magnetite. Morris et al. proposed that the magnetite appears to be igneous in origin, rather than of secondary origin. However, magnetite is not typically found in experimental studies of martian magmatic rocks. Magnetite stability in terrestrial magmas is well understood, as are the stabilities of FeO and Fe2O3 in terrestrial magmas. In order to better understand the variation of FeO and Fe2O3, and the stability of magnetite (and other FeO-bearing phases) in martian magmas, we have undertaken an experimental study with two emphases. First, we determine the FeO and Fe2O3 contents of super- and sub-liquidus glasses from a shergottite bulk composition at 1 bar to 4 GPa, and variable fO2. Second, we document the stability of magnetite with temperature and fO2 in a shergottite bulk composition.

  18. Iron Redox Systematics of Martian Magmas

    NASA Technical Reports Server (NTRS)

    Righter, K.; Danielson, L.; Martin, A.; Pando, K.; Sutton, S.; Newville, M.

    2011-01-01

    Martian magmas are known to be FeO-rich and the dominant FeO-bearing mineral at many sites visited by the Mars Exploration rovers (MER) is magnetite [1]. Morris et al. [1] propose that the magnetite appears to be igneous in origin, rather than of secondary origin. However, magnetite is not typically found in experimental studies of martian magmatic rocks [2,3]. Magnetite stability in terrestrial magmas is well understood, as are the stability of FeO and Fe2O3 in terrestrial magmas [4,5]. In order to better understand the variation of FeO and Fe2O3, and the stability of magnetite (and other FeO-bearing phases) in martian magmas we have undertaken an experimental study with two emphases. First we document the stability of magnetite with temperature and fO2 in a shergottite bulk composition. Second, we determine the FeO and Fe2O3 contents of the same shergottite bulk composition at 1 bar and variable fO2 at 1250 C, and at variable pressure. These two goals will help define not only magnetite stability, but pyroxene-melt equilibria that are also dependent upon fO2.

  19. The Martian Soil: A Planetary Gas Pump

    NASA Astrophysics Data System (ADS)

    De Beule, Caroline; Wurm, G.; Thorben, K.; Küpper, M.; Jankowski, T.; Teiser, J.

    2013-10-01

    The transport of gas through the Martian soil plays an important role in processes like the global cycle of water. Until now, in the absence of an active pumping system, diffusion was assumed to be the most efficient transport mechanism. Here, we present a new mechanism of forced convection within porous soils, which occurs naturally on Mars. In the low pressure environment of Mars, thermal creep within the insolated surface can act as an efficient pump in the porous soil. The pores of the dust act as micro-channels, where the gas flows from the cold to the warm side. We proved this concept in drop tower experiments. In microgravity thermal convection is absent and only thermal creep is visible. By illuminating a basaltic dust bed in microgravity, it was possible to trace the gas flow by embedded particles, moving towards the dust bed within shadowed regions with inflow velocities on the order of cm/s. These observations are consistent with a model of forced flow through the porous medium. Scaled to Martian conditions the experiments show that this transport mechanism can be very efficient and atmospheric gas can be pumped into the soil in shadowed parts and be transported underground to insolated places. This natural planet wide pump is unique in the Solar System as only the Martian surface conditions (mbar pressure) are suitable for this effect.

  20. Opportunity's Second Martian Birthday at Cape Verde

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A promontory nicknamed 'Cape Verde' can be seen jutting out from the walls of Victoria Crater in this approximate true-color picture taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity. The rover took this picture on martian day, or sol, 1329 (Oct. 20, 2007), more than a month after it began descending down the crater walls -- and just 9 sols shy of its second Martian birthday on sol 1338 (Oct. 29, 2007). Opportunity landed on the Red Planet on Jan. 25, 2004. That's nearly four years ago on Earth, but only two on Mars because Mars takes longer to travel around the sun than Earth. One Martian year equals 687 Earth days.

    The overall soft quality of the image, and the 'haze' seen in the lower right portion, are the result of scattered light from dust on the front sapphire window of the rover's camera.

    This view was taken using three panoramic-camera filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

  1. Martian regolith as space radiation shielding.

    PubMed

    Simonsen, L C; Nealy, J E; Townsend, L W; Wilson, J W

    1991-01-01

    In current Mars scenario descriptions, an entire mission is estimated to take 500-1000 days round trip with a 100-600 day stay time on the surface. To maintain radiation dose levels below permissible limits, dose estimates must be determined for the entire mission length. With extended crew durations anticipated on Mars, the characterization of the radiation environment on the surface becomes a critical aspect of mission planning. The most harmful free-space radiation is due to high energy galactic cosmic rays (GCR) and solar flare protons. The carbon dioxide atmosphere of Mars has been estimated to provide a sufficient amount of shielding from these radiative fluxes to help maintain incurred doses below permissible limits. However, Mars exploration crews are likely to incur a substantial dose while in transit to Mars that will reduce the allowable dose that can be received while on the surface. Therefore, additional shielding may be necessary to maintain short-term dose levels below limits or to help maintain career dose levels as low as possible. By utilizing local resources, such as Martian regolith, shielding materials can be provided without excessive launch weight requirements from Earth. The scope of this synopsis and of Ref. 3 focuses on presenting our estimates of surface radiation doses received due to the transport and attenuation of galactic cosmic rays and February 1956 solar flare protons through the Martian atmosphere and through additional shielding provided by Martian regolith. PMID:11537624

  2. Neutron environments on the Martian surface.

    PubMed

    Clowdsley, M S; Wilson, J W; Kim, M H; Singleterry, R C; Tripathi, R K; Heinbockel, J H; Badavi, F F; Shinn, J L

    2001-01-01

    Radiation is a primary concern in the planning of a manned mission to Mars. Recent studies using NASA Langley Research Center's HZETRN space radiation transport code show that the low energy neutron fluence on the Martian surface is larger than previously expected. The upper atmosphere of Mars is exposed to a background radiation field made up of a large number of protons during a solar particle event and mixture of light and heavy ions caused by galactic cosmic rays at other times. In either case, these charged ions interact with the carbon and oxygen atoms of the Martian atmosphere through ionization and nuclear collisions producing secondary ions and neutrons which then interact with the atmospheric atoms in a similar manner. In the past, only these downward moving particles have been counted in evaluating the neutron energy spectrum on the surface. Recent enhancements in the HZETRN code allow for the additional evaluation of those neutrons created within the Martian regolith through the same types of nuclear reactions, which rise to the surface. New calculations using this improved HZETRN code show that these upward moving neutrons contribute significantly to the overall neutron spectrum for energies less than 10 MeV. PMID:11770546

  3. Electrical Activity in Martian Dust Storms

    NASA Astrophysics Data System (ADS)

    Majid, W.

    2015-12-01

    Dust storms on Mars are predicted to be capable of producing electrostatic fields and discharges, even larger than those in dust storms on Earth. Such electrical activity poses serious risks to any Human exploration of the planet and the lack of sufficient data to characterize any such activity has been identified by NASA's MEPAG as a key human safety knowledge gap. There are three key elements in the characterization of Martian electrostatic discharges: dependence on Martian environmental conditions, frequency of occurrence, and the strength of the generated electric fields. We will describe a proposed program using NASA's Deep Space Network (DSN) to carry out a long term monitoring campaign to search for and characterize the entire Mars hemisphere for powerful discharges during routine tracking of spacecraft at Mars on an entirely non-interfering basis. The resulting knowledge of Mars electrical activity would allow NASA to plan risk mitigation measures to ensure human safety during Mars exploration. In addition, these measurements will also allow us to place limits on presence of oxidants such as H2O2 that may be produced by such discharges, providing another measurement point for models describing Martian atmospheric chemistry and habitability. Because of the continuous Mars telecommunication needs of NASA's Mars-based assets, the DSN is the only instrument in the world that combines long term, high cadence, observing opportunities with large sensitive telescopes, making it a unique asset worldwide in searching for and characterizing electrostatic activity at Mars from the ground.

  4. Periglacial and glacial analogs for Martian landforms

    NASA Technical Reports Server (NTRS)

    Rossbacher, Lisa A.

    1992-01-01

    The list of useful terrestrial analogs for Martian landforms has been expanded to include: features developed by desiccation processes; catastrophic flood features associated with boulder-sized materials; and sorted ground developed at a density boundary. Quantitative analytical techniques developed for physical geography have been adapted and applied to planetary studies, including: quantification of the patterns of polygonally fractured ground to describe pattern randomness independent of pattern size, with possible correlation to the mechanism of origin and quantification of the relative area of a geomorphic feature or region in comparison to planetary scale. Information about Martian geomorphology studied in this project was presented at professional meetings world-wide, at seven colleges and universities, in two interactive televised courses, and as part of two books. Overall, this project has expanded the understanding of the range of terrestrial analogs for Martian landforms, including identifying several new analogs. The processes that created these terrestrial features are characterized by both cold temperatures and low humidity, and therefore both freeze-thaw and desiccation processes are important. All these results support the conclusion that water has played a significant role in the geomorphic history of Mars.

  5. Martian meteorites and Martian magnetic anomalies: a new perspective from NWA 7034 (Invited)

    NASA Astrophysics Data System (ADS)

    Gattacceca, J.; Rochette, P.; Scozelli, R. B.; Munayco, P.; Agee, C. B.; Quesnel, Y.; Cournede, C.; Geissman, J. W.

    2013-12-01

    The magnetic anomalies observed above the Martian Noachian crust [1] require strong crustal remanent magnetization in the 15-60 A/m range over a thickness of 20-50 km [2,3]. The Martian rocks available for study in the form of meteorites do contain magnetic minerals (magnetite and/or pyrrhotite) but in too small amount to account for such strong remanent magnetizations [4]. Even though this contradiction was easily explained by the fact that Martian meteorites (mostly nakhlites and shergottites) are not representative of the Noachian Martian crust, we were left with no satisfactory candidate lithology to account for the Martian magnetic anomalies. The discovery in the Sahara of a new type of Martian meteorite (NWA 7034 [5] and subsequent paired stones which are hydrothermalized volcanic breccia) shed a new light on this question as it contains a much larger amount of ferromagnetic minerals than any other Martian meteorite. We present here a study of the magnetic properties of NWA 7034, together with a review of the magnetic properties of thirty other Martian meteorites. Magnetic measurements (including high and low temperature behavior and Mössbauer spectroscopy) show that NWA 7034 contains about 15 wt.% of magnetite with various degrees of substitution and maghemitization up to pure maghemite, in the pseudo-single domain size range. Pyrrhotite, a common mineral in other Martian meteorites is not detected. Although it is superparamagnetic and cannot carry remanent magnetization, nanophase goethite is present in significant amounts confirming that NWA 7034 is the most oxidized Martian meteorite studied so far, as already indicated by the presence of maghemite (this study) and pyrite [5]. These magnetic properties show that a kilometric layer of a lithology similar to NWA 7034 magnetized in a dynamo field would be enough to account for the strongest Martian magnetic anomalies. Although the petrogenesis of NWA 7034 is still debated, as the brecciation could be either

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

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  7. Do Martian Blueberries Have Pits? -- Artifacts of an Early Wet Mars

    NASA Astrophysics Data System (ADS)

    Lerman, L.

    2005-03-01

    Early Martian weather cycles would have supported organic chemical self-organization, the assumed predecessor to an independent "origin" of Martian life. Artifacts of these processes are discussed, including the possibility that Martian blueberries nucleated around organic cores.

  8. An Electrostatic Precipitator System for the Martian Environment

    NASA Technical Reports Server (NTRS)

    Calle, C. I.; Mackey, P. J.; Hogue, M. D.; Johansen, M. R.; Phillips, J. R., III; Clements, J. S.

    2012-01-01

    Human exploration missions to Mars will require the development of technologies for the utilization of the planet's own resources for the production of commodities. However, the Martian atmosphere contains large amounts of dust. The extraction of commodities from this atmosphere requires prior removal of this dust. We report on our development of an electrostatic precipitator able to collect Martian simulated dust particles in atmospheric conditions approaching those of Mars. Extensive experiments with an initial prototype in a simulated Martian atmosphere showed efficiencies of 99%. The design of a second prototype with aerosolized Martian simulated dust in a flow-through is described. Keywords: Space applications, electrostatic precipitator, particle control, particle charging

  9. Fractionated (Martian) Noble Gases — EFA, Experiments and Meteorites

    NASA Astrophysics Data System (ADS)

    Schwenzer, S. P.; Barnes, G.; Bridges, J. C.; Bullock, M. A.; Chavez, C. L.; Filiberto, J.; Herrmann, S.; Hicks, L. J.; Kelley, S. P.; Miller, M. A.; Moore, J. M.; Ott, U.; Smith, H. D.; Steer, E. D.; Swindle, T. D.; Treiman, A. H.

    2016-08-01

    Noble gases are tracers for physical processes, including adsorption, dissolution and secondary mineral formation. We examine the Martian fractionated atmosphere through literature, terrestrial analogs and experiments.

  10. Ultraviolet Radiation-induced Alteration of Martian Surface Materials

    NASA Technical Reports Server (NTRS)

    Yen, A. S.

    1999-01-01

    The nature and origin of martian surface materials cannot be fully characterized without addressing the unusual reactivity of the soil and the effects of exposure to the unique martian environment. Our laboratory experiments show that ultraviolet radiation at the martian surface can result in the oxidation of metal atoms and the creation of reactive oxygen species on grain surfaces. This process is important in understanding the nature and evolution of martian soils. It can explain the reactivity discovered by the Viking Landers and possibly the origin of the ferric component of the soil.

  11. Variability of the Martian thermospheric temperatures during the last 7 Martian Years

    NASA Astrophysics Data System (ADS)

    Gonzalez-Galindo, Francisco; Lopez-Valverde, Miguel Angel; Millour, Ehouarn; Forget, François

    2014-05-01

    The temperatures and densities in the Martian upper atmosphere have a significant influence over the different processes producing atmospheric escape. A good knowledge of the thermosphere and its variability is thus necessary in order to better understand and quantify the atmospheric loss to space and the evolution of the planet. Different global models have been used to study the seasonal and interannual variability of the Martian thermosphere, usually considering three solar scenarios (solar minimum, solar medium and solar maximum conditions) to take into account the solar cycle variability. However, the variability of the solar activity within the simulated period of time is not usually considered in these models. We have improved the description of the UV solar flux included on the General Circulation Model for Mars developed at the Laboratoire de Météorologie Dynamique (LMD-MGCM) in order to include its observed day-to-day variability. We have used the model to simulate the thermospheric variability during Martian Years 24 to 30, using realistic UV solar fluxes and dust opacities. The model predicts and interannual variability of the temperatures in the upper thermosphere that ranges from about 50 K during the aphelion to up to 150 K during perihelion. The seasonal variability of temperatures due to the eccentricity of the Martian orbit is modified by the variability of the solar flux within a given Martian year. The solar rotation cycle produces temperature oscillations of up to 30 K. We have also studied the response of the modeled thermosphere to the global dust storms in Martian Year 25 and Martian Year 28. The atmospheric dynamics are significantly modified by the global dust storms, which induces significant changes in the thermospheric temperatures. The response of the model to the presence of both global dust storms is in good agreement with previous modeling results (Medvedev et al., Journal of Geophysical Research, 2013). As expected, the simulated

  12. Global color variations on the Martian surface

    USGS Publications Warehouse

    Soderblom, L.A.; Edwards, K.; Eliason, E.M.; Sanchez, E.M.; Charette, M.P.

    1978-01-01

    Surface materials exposed throughout the equatorial region of Mars have been classified and mapped on the basis of spectral reflectance properties determined by the Viking II Orbiter vidicon cameras. Frames acquired at each of three wavelengths (0.45 ?? 0.03 ??m, 0.53 ?? 0.05 ??m, and 0.59 ?? 0.05 ??m) during the approach of Viking Orbiter II in Martian summer (Ls = 105??) were mosaicked by computer. The mosaics cover latitudes 30??N to 63??S for 360?? of longitude and have resolutions between 10 and 20 km per line pair. Image processing included Mercator transformation and removal of an average Martian photometric function to produce albedo maps at three wavelengths. The classical dark region between the equator and ???30??S in the Martian highlands is composed of two units: (i) and ancient unit consisting of topographic highs (ridges, crater rims, and rugged plateaus riddled with small dendritic channels) which is among the reddest on the planet (0.59/0.45 ??m {reversed tilde equals} 3); and (ii) intermediate age, smooth, intercrater volcanic plains displaying numerous mare ridges which are among the least red on Mars (0.59/0.45 ??m {reversed tilde equals} 2). The relatively young shield volcanoes are, like the oldest unit, dark and very red. Two probable eolian deposits are recognized in the intermediate and high albedo regions. The stratigraphically lower unit is intermediate in both color (0.59/ 0.45 ??m {reversed tilde equals} 2.5) and albedo. The upper unit has the highest albedo, is very red (0.59/0.45 ??m {reversed tilde equals} 3), and is apparently the major constituent of the annual dust storms as its areal extent changes from year to year. The south polar ice cap and condensate clouds dominate the southernmost part of the mosaics. ?? 1978.

  13. Martian meteorite Dhofar 019: A new shergottite

    NASA Astrophysics Data System (ADS)

    Taylor, L. A.; Nazarov, M. A.; Shearer, C. K.; McSween, H. Y., Jr.; Cahill, J.; Neal, C. R.; Ivanova, M. A.; Barsukova, L. D.; Lentz, R. C.; Clayton, R. N.; Mayeda, T. K.

    2002-08-01

    Dhofar 019 is a new martian meteorite found in the desert of Oman. In texture, mineralogy, and major and trace element chemistry, this meteorite is classified as a basaltic shergottite. Olivine megacrysts are set within a groundmass composed of finer grained olivine, pyroxene (pigeonite and augite), and maskelynite. Minor phases are chromite-ulvöspinel, ilmenite, silica, K-rich feldspar, merrillite, chlorapatite, and pyrrhotite. Secondary phases of terrestrial origin include calcite, gypsum, celestite, Fe hydroxides, and smectite. Dhofar 019 is most similar to the Elephant Moraine (EETA) 79001 lithology A and Dar al Gani (DaG) 476/489 shergottites. The main features that distinguish Dhofar 019 from other shergottites are lack of orthopyroxene; lower Ni contents of olivine; the heaviest oxygen-isotopic bulk composition; and larger compositional ranges for olivine, maskelynite, and spinel, as well as a wide range for pyroxenes. The large compositional ranges of the minerals are indicative of relatively rapid crystallization. Modeling of olivine chemical zonations yield minimum cooling rates of 0.5-0.8 ?C/h. Spinel chemistry suggests that crystallization took place under one of the most reduced conditions for martian meteorites, at an oxygen fugacity of 3 log units below the quartz-fayalite-magnetite (QFM) buffer. The olivine megacrysts are heterogeneously distributed in the rock. Crystal size distribution analysis suggests that they constitute a population formed under steady-state conditions of nucleation and growth, although a few grains may be cumulates. The parent melt is thought to have been derived from partial melting of a light rare earth element- and platinum group element-depleted mantle source. Shergottites, EETA79001 lithology A, DaG 476/489, and Dhofar 019, although of different ages, comprise a particular type of martian rocks. Such rocks could have formed from chemically similar source(s) and parent melt(s), with their bulk compositions affected by

  14. Apollinaris Patera: An Early Martian Mantle Plume?

    NASA Astrophysics Data System (ADS)

    Kiefer, W. S.

    2015-12-01

    Apollinaris Patera is one of the largest volcanos on Mars outside of the Tharsis volcanic province (summit relief 5.4 km, volume 7.3x1013 m3). The mapped crater densities on Apollinaris indicate that volcanic activity ended 3.5 to 3.8 billion years ago. Apollinaris is located on the northern (lowland) side of the martian hemispheric dichotomy. Because it is an isolated, relatively point-like source of volcanism, it is plausibly interpreted as an early example of a martian mantle plume. Plume structure and conditions in the mantle can be constrained using finite element mantle convection simulations combined with a variety of petrological, geophysical, and geologic observations. (1) Basalts studied by the MER Spirit rover in nearby Gusev crater are similar in age and possibly physically connected to Apollinaris Patera. Petrologic modeling of the Gusev crater basalt compositions indicates that the thermal lithosphere was about 100 km thick with a mantle potential temperature of 1480-1530 °C. This requires a mantle thermal Rayleigh number of about 2x108 at the time of volcanism, based on the volume-averaged mantle viscosity. (2) Pyroclastic deposits at Apollinaris indicate that at least a portion of the volcanism occurred in the presence of a high concentration of water or other volatiles. This lowers the solidus temperature and increases the magma production rate but has only a limited effect on the minimum depth of melting. (3) There is a localized magnetic anomaly beneath Apollinaris that indicates that the martian core dynamo persisted until at least the earliest stage of Apollinaris volcanism, which in turn sets a lower bound on the core heat flux of 5-10 mW m-2. Preservation of the magnetic field may be the result of formation of magnetic minerals such as magnetite due to volcanically-driven hydrothermal alteration of crustal rocks beneath Apollinaris.

  15. Modelling the Martian CO2 Ice Clouds

    NASA Astrophysics Data System (ADS)

    Listowski, Constantino; Määttänen, A.; Montmessin, F.; Lefèvre, F.

    2012-10-01

    Martian CO2 ice cloud formation represents a rare phenomenon in the Solar System: the condensation of the main component of the atmosphere. Moreover, on Mars, condensation occurs in a rarefied atmosphere (large Knudsen numbers, Kn) that limits the growth efficiency. These clouds form in the polar winter troposphere and in the mesosphere near the equator. CO2 ice cloud modeling has turned out to be challenging: recent efforts (e.g. [1]) fail in explaining typical small sizes (80 nm-130 nm) observed for mesospheric clouds [2]. Supercold pockets (T<< Tcond), which appear to be common in the mesosphere [3],might be exclusively responsible of the formation of such clouds, as a consequence of gravity waves propagating throughout the atmosphere [4]. In order to understand by modeling the effect CO2 clouds could have on the Martian climate, one needs to properly predict the crystal sizes, and so the growth rates involved. We will show that Earth microphysical crystal growth models, which deal with the condensation of trace gases, are misleading when transposed for CO2 cloud formation: they overestimate the growth rates at high saturation ratios. On the other hand, an approach based on the continuum regime (small Kn), corrected to account for the free molecular regime (high Kn) remains efficient. We present our new approach for modelling the growth of Martian CO2 cloud crystals, investigated with a 1D-microphysical model. [1] Colaprete, A., et al., (2008) PSS, 56, 150C [2] Montmessin, F., et al., (2006) Icarus, 183, 403-410 [3] Montmessin at al., (2011) mamo, 404-405 [4] Spiga, A., et al., (2012), GRL, 39, L02201 [5] Wood, S. E., (1999), Ph.D. thesis, UCLA [6] Young, J. B., J. Geophys. Res., 36, 294-2956, 1993

  16. Fractal Dimension Analysis of Putative Martian Coastlines

    NASA Astrophysics Data System (ADS)

    Gianelli, G. A.

    2005-08-01

    Prior research is equivocal on the existence and location of Martian coastlines. This study proposes a novel method of analyzing putative coastlines; fractal dimensions provide a quantitative measurement of the complexity and nature of a fractal. Geological evidence points to a coastline at the elevation of -3790 meters, called the Deuteronilus contact. It is hypothesized that the fractal dimensions of this putative Martian coastline will be comparable to those of Earth shorelines. A topographic map with a contour line at -3790 meters was obtained from the U. S. Geological Survey, reflecting the most recent Mars Orbiter Laser Altimeter data. The map was cropped into sixty and twenty degree segments, and the putative coastline was isolated from extraneous features. A program which used the box-counting method calculated the fractal dimensions of the putative shorelines. The 22 results were tabulated and compared to 17 fractal dimensions of Earth shorelines, collected from published articles. Ranges were 1.07 to 1.66 for Earth and 1.141 to 1.436 for Mars. The mean was 1.28 for the Mars data and 1.22 for the Earth data, a slight difference that asteroid craters could account for. An unpaired t-test could not prove that the two data sets were significantly different. Although the past existence of a coastline at the Deuteronilus contact cannot be definitively proven without on site investigations, the hypothesis that the fractal dimensions of the putative Martian coastline would be comparable to those of Earth's was accepted, thereby substantiating the claims for the existence of a large northern ocean.

  17. Development of a Martian Sonic Anemometer

    NASA Astrophysics Data System (ADS)

    Dissly, R. W.; Banfield, D. J.; Lasnik, J.; Waters, J. T.; McEwan, I. J.; Richardson, M. I.

    2005-08-01

    This presentation will describe the progress to-date on the development of an acoustic anemometer for the in-situ measurement of wind speeds on Mars, funded by NASA PIDDP. Improved measurements of Martian winds are needed for several reasons: better prediction and understanding of global and regional weather, direct measurement of fluxes between surface/atmosphere of momentum, heat, and trace atmospheric constituents, characterizing and monitoring boundary layer winds that influence the safe delivery of spacecraft to/from the Martian surface, and improved characterization of geologically important aeolian processes that can pose a hazard to future exploration via dust storms and dust devils. Prior attempts to measure surface winds have been limited in capability and difficult to calibrate. Sonic anemometry, measuring wind speed via sound pulse travel-time differences, can overcome many of these issues. Sonic anemometry has several distinct advantages over other methods such as hot wire techniques: higher sensitivity ( <5 cm/s), higher time resolution (10-100 Hz), and fewer intrinsic biases for improved accuracy. Together, these open the possibility of resolving turbulent boundary layer eddies to directly capture surface-to-atmospheric fluxes for the first time. We will describe the results of our development of an acoustic anemometer using capacitive micro-machined devices, optimized for acoustic coupling in a low-pressure medium like the Martian atmosphere. This development includes transducer characterization tests in a pressure chamber at Ball Aerospace with Mars-relevant CO2 pressures. We will also describe experimental results showing that the addition of water in a low-pressure CO2 atmosphere can significantly increase acoustic attenuation. Finally we will describe plans for further optimization of the instrument for future Mars payloads.

  18. The Martian Chronicles. A Sound Filmstrip Program. Study Guide.

    ERIC Educational Resources Information Center

    Christesen, Barbara

    This filmstrip study guide dramatizes several stories from Ray Bradbury's "The Martian Chronicles" concerning basic issues of human nature: the need to respect cultural differences and the importance of preserving the environment. A collection of 26 short stories, "The Martian Chronicles" describes the colonization of Mars. The personal and…

  19. Endolithic microbial model for Martian exobiology: The road to extinction

    NASA Technical Reports Server (NTRS)

    Oscampo-Friedmann, R.; Friedmann, E. I.

    1991-01-01

    Martian exobiology is based on the assumption that on early Mars, liquid water was present and that conditions were suitable for the evolution of life. The cause for life to disappear from the surface and the recognizable fingerprints of past microbial activity preserved on Mars are addressed. The Antarctic cryptoendolithic microbial ecosystem as a model for extinction in the deteriorating Martian environment is discussed.

  20. Solar neutrinos, Martian rivers, and Praesepe.

    NASA Technical Reports Server (NTRS)

    Sagan, C.; Young, A. T.

    1973-01-01

    Some recent papers on solar neutrinos, Martian rivers, and Praesepe stars are reviewed. Possible causes of solar neutrino detection rates being below theoretical expectations are quoted. The widespread presence of sinuous dendritic channels on Mars is noted. The occurrence of earth-like epochs on Mars is indicated as a plausible explanation for many such channels in terms of surface liquid water flows. The roughly uniform distribution of the Praesepe stars through the main sequence width is viewed as the indication that the excursion time off the main sequence is comparable to the time between mixings.

  1. Nighttime Clouds in Martian Arctic (Accelerated Movie)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    An angry looking sky is captured in a movie clip consisting of 10 frames taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander.

    The clip accelerates the motion. The images were take around 3 a.m. local solar time at the Phoenix site during Sol 95 (Aug. 30), the 95th Martian day since landing.

    The swirling clouds may be moving generally in a westward direction over the lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  2. Design considerations for a Martian Balloon Rover

    NASA Technical Reports Server (NTRS)

    Redd, F.; Levesque, R. J.; Williams, G. E.

    1987-01-01

    The present NASA-sponsored design feasibility study for a balloon-borne sensor platform that is to be used over environmentally dissimilar sites on Mars gives attention to specific environmental and configurational parameters of a baseline balloon design, with a view to day/night altitude variations in response to temperature extremes. It is concluded that a Martian Balloon Rover can be developed using current technology; projected reductions in high-strength fabric density and radiation-resistant coatings will further enhance mission effectiveness, permitting either balloon size reductions or payload capacity increases.

  3. Phoenix's Probe Inserted in Martian Soil

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Phoenix Mars lander's robotic-arm camera took this image of the spacecraft's thermal and electrical-conductivity probe (TECP) inserted into Martian soil on day 149 of the mission. Phoenix landed on Mars' northern plains on May 25, 2008, landing.

    The robotic-arm camera acquired this image at 16:02:41 local solar time. The camera pointing was elevation -72.6986 degrees and azimuth 2.1093 degrees.

    The Phoenix mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  4. Photometric Observations of Martian Trojan Asteroids

    NASA Astrophysics Data System (ADS)

    Borisov, Galin; Christou, Apostolos; Unda-Sanzana, Eduardo

    2016-07-01

    We present R filter photometry of the Martian Trojan asteroids (101429) 1998 VF31 and (385250) 2001 DH47, carried out with the 2-m RCC and 1.3-m SMARTS telescopes during 11 nights in 2015 November and 2016 January. A periodogram analysis of the lightcurves suggests a rotation period of P = 7.70h with a low amplitude (A < 0.1 mag) for 1998 VF31 and P = 3.97h with amplitude A ~ 0.6mag for 2001 DH47.

  5. Coastal geomorphology of the Martian northern plains

    NASA Technical Reports Server (NTRS)

    Parker, Timothy J.; Gorsline, Donn S.; Saunders, Stephen R.; Pieri, David C.; Schneeberger, Dale M.

    1993-01-01

    The paper considers the question of the formation of the outflow channels and valley networks discovered on the Martian northern plains during the Mariner 9 mission. Parker and Saunders (1987) and Parker et al. (1987, 1989) data are used to describe key features common both in the lower reaches of the outflow channels and within and along the margins of the entire northern plains. It is suggested, that of the geological processes capable of producing similar morphologies on earth, lacustrine or marine deposition and subsequent periglacial modification offer the simplest and most consistent explanation for the suit of features found on Mars.

  6. An Examination of "The Martian" Trajectory

    NASA Technical Reports Server (NTRS)

    Burke, Laura

    2015-01-01

    This analysis was performed to support a request to examine the trajectory of the Hermes vehicle in the novel "The Martian" by Andy Weir. Weir developed his own tool to perform the analysis necessary to provide proper trajectory information for the novel. The Hermes vehicle is the interplanetary spacecraft that shuttles the crew to and from Mars. It is notionally a Nuclear powered vehicle utilizing VASIMR engines for propulsion. The intent of this analysis was the determine whether the trajectory as it was outlined in the novel is consistent with the rules of orbital mechanics.

  7. Assay of the Martian Regolith with Neutrons

    NASA Technical Reports Server (NTRS)

    Drake, Darrell M.; Reedy, R.; Jakowsky, B.; Clark, B.; Squyres, S.

    1998-01-01

    Different aspects of assaying Martian regolith using neutrons have been investigated. The epithermal portion of moderated neutrons spectra is dramatically effected by the presence of hydrogen (usually in the form of water). A simple analytic formula has been derived to describe the amplitude of this portion of the neutron spectrum as a function of water concentration. Several demonstration experiments have been performed and modeled with a Monte Carlo code. Results of these experiments generally agreed with the calculations to within 20%. In addition to He-3 detectors, lithium-glass scintillators and U-238 fission ion chambers were investigated to determine their applicability to space experiments.

  8. Katabatic jumps over Martian polar terrains

    NASA Astrophysics Data System (ADS)

    Spiga, Aymeric; Smith, Isaac; Holt, Jack

    2015-04-01

    Recent observational and modeling studies have shed light on the key role of mesoscale phenomena in driving the Martian climate and giving rise to remarkable signatures in the temperature, wind, pressure, and aerosol fields of the Martian atmosphere. At the mesoscale, Mars appears as an intense and exotic counterpart to the Earth, mainly as a result of pronounced diurnal and regional contrasts of surface temperature, and the much thinner atmosphere. While observations of clear-cut katabatic events are difficult on Earth, except over vast ice sheets, those intense downslope circulations are widespread on Mars owing to near-surface radiative cooling and uneven topography. Their intensity and regularity can be witnessed through numerous aeolian signatures on the surface, and distinctive thermal signatures in the steepest craters and volcanoes. Several observations (radar observations, frost streaks, spectral analysis of ices, ...) concur to show that aeolian processes play a key role in glacial processes in Martian polar regions over geological timescales. A spectacular manifestation of this resides in elongated clouds that forms at the bottom of polar spiral troughs, which dominates the polar landscape both in the North and South. An analogy with the terrestrial "wall-of-snow" over e.g. Antarctica slopes or coastlines posits that those clouds are caused by local katabatic jumps, also named Loewe phenomena, which can be deemed similar to first order to hydraulic jumps in open channel flow. With mesoscale modeling in polar regions using 5 nested domains operating a model downscaling from horizontal resolutions of about twenty kilometers to 200 meters, we were able 1. to predict the near-surface wind structure over the whole Martian polar caps, with interactions between katabatic acceleration, Coriolis deflection, transient phenomena, and thermally-forced circulations by the ice / bare soil contrast and 2. to show that katabatic jumps form at the bottom of polar troughs

  9. Linear baroclinic instability in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Barnes, J. R.

    1984-05-01

    A spherical quasi-geostrophic model is used in an examination of linear baroclinic instability in such zonal-mean flows as those of the Martian atmosphere in winter, under both relatively nondusty and very dusty conditions. These zonal flows, which possess both vertical and meridional shear, are characterized by baroclinically unstable modes whose growth rates and phase speeds are generally consistent with available observations. The structures of the spherical modes are similar to those obtained for terrestrial zonal flows, if similar zonal wavelengths are compared. Zonally symmetric topography, like that of Mars' northern hemisphere, reduces linear growth rates without changing the most unstable scale. It also increases phase speeds.

  10. Carbonates in Martian Meteorites - A Reappraisal

    NASA Astrophysics Data System (ADS)

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

    1995-09-01

    The occurrence of carbonates in martian meteorites was first established after acid dissolution and stepped combustion analyses of whole-rock Nakhla [1]. The release of CO2 after a 24 hr. reaction with 100% H3PO4 at 25 degrees C was taken to imply that the carbonate mineral present was calcite, a proposal subsequently confirmed by petrographic examination [2]. The isotopic composition of the carbon comprising the calcite was enriched in 13C (isotopically heavy) with delta^(l3)C ~ +12 per mil. An extended period of acid attack, also at 25 degrees C, released small quantities of even more 13C-enriched CO2 (delta^(13)C ~ +49 per mil), but the isotopic data were considered uncertain, and thus little significance was attached to the result, beyond the suggestion that some carbonate was perhaps dolomite or iron-bearing. Now, however, following the analysis of Fe-Mg-rich carbonates in ALH 84001 [3-5], it is apparent that previously-reported data might underestimate the abundance and delta^(13)C of carbonates in SNCs [6], and that a much higher proportion might occur as siderite or dolomite end-members. Iron- and magnesium-rich carbonates are only partially attacked at 25 degrees C, even after extended exposure to H3PO4 [7]. Given that the delta^(13)C of carbonates in SNCs has been used to deduce both environmental conditions on Mars [4, 6], and the evolution of the martian atmosphere [8], it is desirable that correct delta^(l3)c values are known. We have undertaken a reappraisal of the chemical and isotopic composition of carbonates in martian meteorites, by a programme of high resolution stepped combustion analyses and high temperature (75 degrees C) acid dissolution . Carbonates in most martian meteorites are extremely fine-grained. and therefore not easv to identify by traditional optical microscopic methods; it is not possible to determine readily the mineralogical composition of the grains. Comparison of combustion data from SNCs with that from pure materials allows

  11. Experimental simulation of early Martian volcanic lightning.

    PubMed

    Segura, A; Navarro-Gonzalez, R

    2001-01-01

    A mixture of possible Martian volcanic gases were reproduced and irradiated by a high-energy infrared laser to reproduce the effects of lightning on the production of prebiotic molecules. The analysis of products were performed by a gas chromatograph interfaced in parallel with a FTIR-detector and a quadrupole mass spectrometer equipped with an electron impact and chemical ionization modes. The main products identified were hydrocarbons and an uncharacterized yellow film deposit. Preliminary results indicate the presence of hydrogen cyanide among the resultant compounds. PMID:11605634

  12. The dynamics of Martian satellites from observations

    NASA Astrophysics Data System (ADS)

    Emelyanov, N. V.; Vashkovyak, S. N.; Nasonova, L. P.

    1993-01-01

    This paper deals with the study of the motion of Martian satellites and with the determination of kinematic and dynamic parameters describing this system of satellites and planet. The values of these parameters are found on the basis of all available data of ground-based and space-based observations of Phobos and Deimos. The original analytical theory of the motion of the satellites was used and the data set was wider than in similar papers of other authors. Thus, a new specified model of the motion of Mars' satellites has been constructed.

  13. The Preliminary Design of a Universal Martian Lander

    NASA Technical Reports Server (NTRS)

    Norman, Timothy L.; Gaskin, David; Adkins, Sean; MacDonnell, David; Ross, Enoch; Hashimoto, Kouichi; Miller, Loran; Sarick, John; Hicks, Jonathan; Parlock, Andrew; Swalley, Frank (Technical Monitor)

    1993-01-01

    As part of the NASA/USRA program, nineteen West Virginia University students conducted a preliminary design of a manned Universal Martian Lander (UML). The WVU design considers descent to Mars from polar orbit, a six month surface stay, and ascent for rendezvous. The design begins with an unmanned UML landing at Elysium Mons followed by the manned UML landing nearby. During the six month surface stay, the eight modules are assembled to form a Martian base where scientific experiments are performed. The mission also incorporates hydroponic plant growth into a Controlled Ecological Life Support System (CELSS) for water recycling, food production, and to counteract psycho-logical effects of living on Mars. In situ fuel production for the Martian Ascent and Rendezvous Vehicle (MARV) is produced From gases in the Martian atmosphere. Following surface operations, the eight member crew uses the MARV to return to the Martian Transfer Vehicle (MTV) for the journey home to Earth.

  14. An extensive phase space for the potential martian biosphere.

    PubMed

    Jones, Eriita G; Lineweaver, Charles H; Clarke, Jonathan D

    2011-12-01

    We present a comprehensive model of martian pressure-temperature (P-T) phase space and compare it with that of Earth. Martian P-T conditions compatible with liquid water extend to a depth of ∼310 km. We use our phase space model of Mars and of terrestrial life to estimate the depths and extent of the water on Mars that is habitable for terrestrial life. We find an extensive overlap between inhabited terrestrial phase space and martian phase space. The lower martian surface temperatures and shallower martian geotherm suggest that, if there is a hot deep biosphere on Mars, it could extend 7 times deeper than the ∼5 km depth of the hot deep terrestrial biosphere in the crust inhabited by hyperthermophilic chemolithotrophs. This corresponds to ∼3.2% of the volume of present-day Mars being potentially habitable for terrestrial-like life.

  15. An extensive phase space for the potential martian biosphere.

    PubMed

    Jones, Eriita G; Lineweaver, Charles H; Clarke, Jonathan D

    2011-12-01

    We present a comprehensive model of martian pressure-temperature (P-T) phase space and compare it with that of Earth. Martian P-T conditions compatible with liquid water extend to a depth of ∼310 km. We use our phase space model of Mars and of terrestrial life to estimate the depths and extent of the water on Mars that is habitable for terrestrial life. We find an extensive overlap between inhabited terrestrial phase space and martian phase space. The lower martian surface temperatures and shallower martian geotherm suggest that, if there is a hot deep biosphere on Mars, it could extend 7 times deeper than the ∼5 km depth of the hot deep terrestrial biosphere in the crust inhabited by hyperthermophilic chemolithotrophs. This corresponds to ∼3.2% of the volume of present-day Mars being potentially habitable for terrestrial-like life. PMID:22149914

  16. Agent Orange

    MedlinePlus

    ... Index Agent Orange Agent Orange Home Facts about Herbicides Veterans' Diseases Birth Defects Benefits Exposure Locations Provider ... millions of gallons of Agent Orange and other herbicides on trees and vegetation during the Vietnam War. ...

  17. Electrical Breakdown in a Martian Gas Mixture

    NASA Technical Reports Server (NTRS)

    Buhler, C. R.; Calle, C. I.; Nelson, E.

    2003-01-01

    The high probability for dust interactions during Martian dust storms and dust devils combined with the cold, dry climate of Mars most likely result in airborne dust that is highly charged. On Earth, potential gradients up to 5 kV/m have been recorded and in some cases resulted in lightning. Although the Martian atmosphere is not conducive to lightning generation, it is widely believed that electrical discharge in the form of a corona occurs. In order to understand the breakdown of gases, Paschen measurements are taken which relate the minimum potential required to spark across a gap between two electrodes. The minimum potential is plotted versus the pressure-distance value for electrodes of a given geometry. For most gases, the potential decreases as the pressure decreases. For CO2, the minimum in the curve happens to be at Mars atmospheric pressures (5-7 mm Hg) for many distances and geometries. However, a very small amount (<0.1%) of mixing gases radically changes the curve, as noted by Leach. Here, we present the first experimental results of a Paschen curve for a Mars gas mixture compared with 100% pure CO2.

  18. Physicochemical properties of concentrated Martian surface waters

    NASA Astrophysics Data System (ADS)

    Tosca, Nicholas J.; McLennan, Scott M.; Lamb, Michael P.; Grotzinger, John P.

    2011-05-01

    Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features all underscore the need to understand the physical properties of highly concentrated solutions on Mars in addition to, and as a function of, their distinct chemistry. Using thermodynamic models predicting saline mineral solubility, we generate likely brine compositions ranging from bicarbonate-dominated to sulfate-dominated and predict their saline mineralogy. For each brine composition, we then estimate a number of thermal, transport, and colligative properties using established models that have been developed for highly concentrated multicomponent electrolyte solutions. The available experimental data and theoretical models that allow estimation of these physicochemical properties encompass, for the most part, much of the anticipated variation in chemistry for likely Martian brines. These estimates allow significant progress in building a detailed analysis of physical sedimentation at the ancient Martian surface and allow more accurate predictions of thermal behavior and the diffusive transport of matter through chemically distinct solutions under comparatively nonstandard conditions.

  19. Martian resource locations: Identification and optimization

    NASA Astrophysics Data System (ADS)

    Chamitoff, Gregory; James, George; Barker, Donald; Dershowitz, Adam

    2005-04-01

    The identification and utilization of in situ Martian natural resources is the key to enable cost-effective long-duration missions and permanent human settlements on Mars. This paper presents a powerful software tool for analyzing Martian data from all sources, and for optimizing mission site selection based on resource collocation. This program, called Planetary Resource Optimization and Mapping Tool (PROMT), provides a wide range of analysis and display functions that can be applied to raw data or imagery. Thresholds, contours, custom algorithms, and graphical editing are some of the various methods that can be used to process data. Output maps can be created to identify surface regions on Mars that meet any specific criteria. The use of this tool for analyzing data, generating maps, and collocating features is demonstrated using data from the Mars Global Surveyor and the Odyssey spacecraft. The overall mission design objective is to maximize a combination of scientific return and self-sufficiency based on utilization of local materials. Landing site optimization involves maximizing accessibility to collocated science and resource features within a given mission radius. Mission types are categorized according to duration, energy resources, and in situ resource utilization. Preliminary optimization results are shown for a number of mission scenarios.

  20. Martian lithospheric thickness from elastic flexure theory

    NASA Technical Reports Server (NTRS)

    Thurber, C. H.; Toksoz, M. N.

    1978-01-01

    The thickness of the elastic lithosphere in the Tharsis region of Mars is estimated from effects due to the surface load of Olympus Mons. Deformation (vertical displacement) and stress are calculated using elastic flexure theory for a range of possible lithospheric thicknesses (T), modeling the lithosphere as a thin elastic shell and the interior as a Newtonian fluid. For T below 150 km, displacement and stress rise rapidly with decreasing thickness. For T near 100 km, deformation of the region surrounding the volcano would be clearly visible in the topography, and resulting tensional stresses exceeding 5 kbar should produce observable fracturing at the surface. In contrast, for T near 200 km deformation is minimal and the tensional stress, being less than a kilobar, would not result in extensive fracturing. Since significant deformation and fracturing are not observed, it is concluded that the Martian elastic lithosphere is at least 150 km in thickness. Seismic, tectonic, and gravity observations all suggest a thick Martian lithosphere as well.

  1. Amino acids in the Martian meteorite Nakhla

    PubMed Central

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

    1999-01-01

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

  2. Phoenix Conductivity Probe Inserted into Martian Soil

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Phoenix Mars Lander inserted the four needles of its thermal and conductivity probe into Martian soil during the 98th Martian day, or sol, of the mission and left it in place until Sol 99 (Sept. 4, 2008).

    The Robotic Arm Camera on Phoenix took this image on the morning of Sol 99 while the probe's needles were in the ground. The science team informally named this soil target 'Gandalf.'

    The thermal and conductivity probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water.

    The probe is part of Phoenix's Microscopy, Electrochemistry and Conductivity suite of instruments.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  3. Wind tunnel studies of Martian aeolian processes

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Iversen, J. D.; Pollack, J. B.; Udovich, N.; White, B.

    1973-01-01

    Preliminary results are reported of an investigation which involves wind tunnel simulations, geologic field studies, theoretical model studies, and analyses of Mariner 9 imagery. Threshold speed experiments were conducted for particles ranging in specific gravity from 1.3 to 11.35 and diameter from 10.2 micron to 1290 micron to verify and better define Bagnold's (1941) expressions for grain movement, particularly for low particle Reynolds numbers and to study the effects of aerodynamic lift and surface roughness. Wind tunnel simulations were conducted to determine the flow field over raised rim craters and associated zones of deposition and erosion. A horseshoe vortex forms around the crater, resulting in two axial velocity maxima in the lee of the crater which cause a zone of preferential erosion in the wake of the crater. Reverse flow direction occurs on the floor of the crater. The result is a distinct pattern of erosion and deposition which is similar to some martian craters and which indicates that some dark zones around Martian craters are erosional and some light zones are depositional.

  4. Amino acids in the Martian meteorite Nakhla

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  5. Charge Balance in the Martian Ionosphere

    NASA Astrophysics Data System (ADS)

    Esman, Teresa; Yelle, Roger V.; Stone, Shane W.; Andersson, Laila; Fowler, Christopher Michael; Benna, Mehdi; Eparvier, Francis; Mahaffy, Paul; Ergun, Bob; Elrod, Meredith K.; MAVEN

    2016-10-01

    We present empirical models of the Martian ionosphere in conjunction with data from the Langmuir Probe and Waves (LPW), Neutral Gas and Ion Mass Spectrometer (NGIMS), and Extreme Ultraviolet Monitor (EUVM) instruments aboard the Mars Atmosphere and Volatile Evolution mission (MAVEN) spacecraft. Among the data provided by MAVEN are electron densities and temperatures, ion and neutral densities, and solar extreme ultraviolet (EUV) flux. We explore a number of contributors to the CO2 photoionization rate, with a specific focus on the role of electron temperatures, which, prior to MAVEN, were not well-known. We compare our results with expectations of the ionospheric structure and behavior to confirm our understanding of the basic structure of the Martian ionosphere in the photochemical region. We show that the ionosphere of Mars is well matched by photochemical equilibrium to within the accuracy of the measurements. These results will aid in the development of more complex ionospheric and escape models and lead to a comprehensive and global scale picture of thermal ion escape on Mars.

  6. Indirect detection of the Martian helium corona

    NASA Astrophysics Data System (ADS)

    Barabash, S.; Norberg, O.

    1994-07-01

    The ion composition mass spectrometer ASPERA on board the PHOBOS 2 spacecraft detected particles with M/q = 4 in the vicinity of Mars. A significant difference between the measured particle velocity and the solar wind velocity suggests that these ions are of planetary origin, apparently He(+) from ionisation within the Martian helium corona. The particles had typical energies of either more than 10 keV or about 500 eV. The former correspond to ion pickup in the solar wind and the latter might be ions extracted from the upper ionosphere by an electric field. The observed density of pickup He(+) ions was 0.02-0.1/cc and the He(+) density in the plasmasheet was of 0.2-0.7/cc. According to a recent model of the Martian neutral atmosphere (Moroz et al, 1991) the He(+) density could reach 0.2/cc at the Phobos orbit. Such values give mass densities comparable to those of the solar wind. Thus, helium may play a role in the solar wind mass loading process near Mars.

  7. Formation Timescales of the Martian Valley Networks

    NASA Astrophysics Data System (ADS)

    Hoke, M. T.; Hynek, B. M.

    2010-12-01

    The presence of valley networks across much of the ancient surface of Mars [e.g. 1] together with the locations and morphologies of the Martian deltas [e.g. 2] and ancient paleolakes [e.g. 3, 4], provides strong evidence that the Martian surface environment was once capable of sustaining long-lived flowing water. Many of the larger Martian valley networks exhibit characteristics consistent with their formation primarily from surface runoff of precipitated water [5-7]. Their formation likely followed similar processes as those that formed terrestrial river valleys, including the gradual erosion and transport of sediment downstream by bed load, suspended load, and wash load processes. When quantifying flow rates on Mars, some researchers have modified the Manning equation for depth- and width-averaged flow velocity in an attempt to better-fit Martian conditions [e.g. 3, 8-10]. These attempts, however, often result in flow velocities on Mars that are overestimated by up to a factor of two [10]. An alternative to the Manning equation that is often overlooked in the planetary science community is the Darcy-Weisbach (D-W) equation [11], which, unlike the Manning equation, maintains a dependence on the acceleration due to gravity. Although the D-W equation relies on a dimensionless friction function that has been fitted to terrestrial data, it is not a constant like the Manning coefficient. Rather, the D-W friction factor is a function of bed slope, flow depth, and median grain size [e.g. 8, 10, 12-14], and therefore it is better suited to model flow velocity on Mars. In this work, we investigate the formation timescales of the Martian valley networks through the use of four different sediment transport models [14], the D-W equation for average flow velocity, and a variety of parameters to encompass a range of possible formation conditions. This is done specific to each of eight large valley networks, all of which have crater densities that place their formation in the

  8. Composition of Simulated Martian Brines and Implications for the Origin of Martian Salts

    NASA Technical Reports Server (NTRS)

    Bullock, M. A.; Moore, J. M.; Mellon, M. T.

    2004-01-01

    We report on laboratory experiments that have produced dilute brines under controlled conditions meant to simulate past and present Mars. We allowed an SNC-derived mineral mix to react with pure water under a simulated present-Mars atmosphere for seven months. We then subjected the same mineral mix to a similar aqueous environment for one year, but with a simulated Mars atmosphere that contained the added gases SO2, HCl and NO2. The addition of acidic gases was designed to mimic the effects of volcanic gases that may have been present in the martian atmosphere during periods of increased volcanic activity. The experiments were performed at one bar and at two different temperatures in order to simulate subsurface conditions where liquid water and rock are likely to interact on Mars. The dominant cations dissolved in the solutions we produced were Ca(2+), Mg(2+), Al(3+) and Na(+), while the major anions are dissolved C, F(-), SO4(2-) and Cl(-). Typical solution pH was 4.2 to 6.0 for experiments run with a Mars analog atmosphere, and 3.6-5.0 for experiments with acidic gases added. Abundance patterns of elements in the synthetic sulfate-chloride brines produced under acidic conditions were distinctly unlike those of terrestrial ocean water, terrestrial continental waters, and those measured in the martian fines at the Mars Pathfinder and Viking 1 and 2 landing sites. In particular, the S/Cl ratio in these experiments was about 200, compared with an average value of approx. 5 in martian fines. In contrast, abundance patterns of elements in the brines produced under a present day Mars analog atmosphere were quite similar to those measured in the martian fines at the Mars Pathfinder and Viking 1 and 2 landing sites. This suggests that salts present in the martian regolith may have formed over time as a result of the interaction of surface or subsurface liquid water with basalts in the presence of a martian atmosphere similar in composition to that of today, rather than

  9. Field Studies of Gullies and Pingos on Svalbard - a Martian Analog.

    NASA Astrophysics Data System (ADS)

    Carlsson, E.; Johannsson, H. A. B.; Johnsson, A.; Heldmann, J. L.; McKay, C. P.; Olvmo, M.; Johansson, L.; Fredriksson, S.; Schmidt, H. T.; McDaniel, S.; Reiss, D.; Hiesinger, H.; Hauber, E.; Zanetti, M.

    2008-09-01

    Introduction: The gully systems on Mars [1] have been found to superpose young geological surfaces such as dunes and thermal contraction polygons [2]. This in combination with the general absence of superimposed impact craters suggest that the gullies are relatively recent geological formations [3]. The observed gullies display a wide set of morphologies ranging from features seemingly formed by fluvial erosion to others pointing to dry landslide processes. A recent discovery [4] suggests that this is an ongoing process, which appears to occur even today. Several formation mechanisms have been proposed for the Martian gullies, such as liquid carbon dioxide reservoirs [5], shallow liquid water aquifer [6], melting ground ice [7], dry landslide [8], snow melt [9] and deep liquid water aquifer [10]. However, none of these models can alone explain all the gullies discovered on Mars. So far Martian gullies have been studied only from orbit via remote sensing data. Hydrostatic pingos are perennial ice-cored mounds that may reach an elongated or circular radius of approximately 150 m. They are found in periglacial environments where they are formed by freezing processes in the continuous permafrost. The pingos go through different evolutionary stages as they mature, where the final stage leaves an annular rim left by the collapse of the summit. Images from the High Resolution Imaging Science Experiment (HiRISE) show small fractured mounds in the Martian mid-latitudes [11]. Even though some differences are observed, the best terrestrial analogues for the observed mound morphology are pingos [11]. Gullies and pingos found in Arctic climates on Earth could be an analog for the Martian ones. A comparative analysis might help to understand the formation mechanisms of the Martian pingos and gullies and their possible eroding agent. Svalbard as a Martian Analog: Svalbard is situated at 74°-81°N and 10°-35°E, in the discontinuous zone of permafrost, and is a fairly good

  10. Survival of microorganisms in smectite clays: Implications for Martian exobiology

    NASA Astrophysics Data System (ADS)

    Moll, Deborah M.; Vestal, J. Robie

    1992-08-01

    Manned exploration of Mars may result in the contamination of that planet with terrestrial microbes, a situation requiring assessment of the survival potential of possible contaminating organisms. In this study, the survival of Bacillus subtilis, Azotobacter chroococcum, and the enteric bacteriophage MS2 was examined in clays representing terrestrial (Wyoming type montmorillonite) or Martian (Fe 3+-montmorillonite) soils exposed to terrestrial and Martian environmental conditions of temperature and atmospheric pressure and composition, but not to UV flux or oxidizing conditions. Survival of bacteria was determined by standard plate counts and biochemical and physiological measurements over 112 days. Extractable lipid phosphate was used to measure microbial biomass, and the rate of 14C-acetate incorporation into microbial lipids was used to determine physiological activity. MS2 survival was assayed by plaque counts. Both bacterial types survived terrestrial or Martian conditions in Wyoming montmorillonite better than Martian conditions in Fe 3+-montmorillonite. Decreased survival may have been caused by the lower pH of the Fe 3+-montmorillonite compared to Wyoming montmorillonite. MS2 survived simulated Mars conditions better than the terrestrial environment, likely due to stabilization of the virus caused by the cold and dry conditions of the simulated Martian environment. The survival of MS2 in the simulated Martian environment is the first published indication that viruses may be able to survive in Martian type soils. This work may have implications for planetary protection for future Mars missions.

  11. Field Measurements of Terrestrial and Martian Dust Devils

    NASA Astrophysics Data System (ADS)

    Murphy, Jim; Steakley, Kathryn; Balme, Matt; Deprez, Gregoire; Esposito, Francesca; Kahanpää, Henrik; Lemmon, Mark; Lorenz, Ralph; Murdoch, Naomi; Neakrase, Lynn; Patel, Manish; Whelley, Patrick

    2016-09-01

    Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types.

  12. Limits on UV Photodecomposition of Martian Carbonates

    NASA Astrophysics Data System (ADS)

    Quinn, R. C.; Zent, A. P.

    2001-11-01

    Lack of unambiguous spectral evidence for carbonates on Mars has led to the suggestion that they maybe unstable on the martian surface. Mukhin et al. (1996) conducted experiments in which natural calcite was exposed under vacuum to UV light. They reported a quantum yield for the photo-induced decomposition of carbonate of 10-5 molecules/photon and a threshold effect at 350-400 nm. This is surprising because of the high threshold effect and because previous work (Booth and Kieffer 1978) had shown that carbonates form under conditions similar to those on Mars even with UV light present. Additionally, the Mukhin results may not be applicable to Mars because of the low partial pressure of CO2 in their system. We have experimentally investigated the UV photo-induced decomposition of calcium carbonate under a simulated Martian atmosphere to assess more realistically the efficacy of the process on Mars. In these experiments, 13C labeled CO2 was used to allow products of carbonate decomposition to be differentiated from the simulated Mars atmosphere. No 13C-carbon dioxide release was observed in experiments run at temperatures below 323K, indicating either that UV decomposition of carbonate does not occur in a 10 mbar Mars atmosphere, or that the decomposition did not exceed the system lower limit of detection. Extrapolating the lower detection limit (3x10-8 molecules/photon) to an upper limit of carbonate decomposition at the surface of Mars yields a maximum UV photodecomposition loss rate from bulk calcite of about 2 nm/yr. We conclude that it is unlikely that the apparent absence of carbonate on the martian surface is due to UV photodecomposition of carbonates in the current environment. Support for this work was provided by the NASA Exobiology Program. References: Booth, M. C., H. H. Kieffer, J. Geophys. Res., 83, 1809-1815, 1976 Mukhin, L.M., A.P. Koscheev, Y.P. Dikov, J. Huth, H. Wanke, Nature, 379, 141-143, 1996.

  13. A Genetic Cluster of Martian Trojan Asteroids

    NASA Astrophysics Data System (ADS)

    Christou, Apostolos

    2013-10-01

    Trojan asteroids lead 60 degrees ahead (L4) or trail 60 degrees behind (L5) a planet's position along its orbit. The Trojans of Jupiter and Neptune are thought to be primordial remnants from the solar system's early evolution (Shoemaker et al., 1989; Sheppard et al., 2006). Mars is the only terrestrial planet known to host stable Trojans (Scholl et al., 2005) with ~50 km-sized objects expected to exist (Tabachnik and Evans, 1999). I identified 6 additional candidate Martian Trojans within the Minor Planet Center database, including three with multi-opposition orbits. 100 dynamical clones for each of the three asteroids were integrated for 100 Myr under a force model that included the Yarkovsky effect. All clones persisted as L5 Trojans of Mars, implying that their residence time is longer still. This is further supported by recent Gyr numerical integrations (de la Fuente Marcos and de la Fuente Marcos, 2013). The number of stable Martian Trojans is thus raised to 7, 6 of which are at L5. To investigate this asymmetry, I apply a clustering test to their orbits and compare them with the Trojan population of Jupiter. I find that, while Jupiter Trojans are spread throughout the domain where long-term stability is expected, L5 martian Trojans are far more concentrated. The implication is that these objects may be genetically related to each other and to the largest member of the group, 5261 Eureka. If so, it represents the closest such group to the Earth's orbit, still recognizable due to the absence of planetary close encounters which quickly scatter NEO families (Schunova et al., 2012). I explore the origin and nature of this `Eureka cluster', including the thesis that its members are products of the collisional fragmentation and/or rotational fission of Trojan progenitors. I constrain the cluster's age under these scenarios and argue that collisions may be responsible for the observed paucity of km-sized objects. Finally, I discuss how the hypothesis of a genetic

  14. The long winter model of Martian biology - A speculation.

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1971-01-01

    A temporal microenvironment model is proposed for Martian biology that is based on an estimated mean thickness of nearly 1 km of frost in the Martian north polar cap summer remnant. If vaporized, this frost could yield not only 1 kg per sq cm of atmosphere, but also higher global temperatures through the greenhouse effect and a greatly increased likelihood of liquid water. Vaporization of such cap remnants may occur twice each equinoctial precession, and Martian organisms may now be in cryptobiotic repose awaiting the end of the long precessional winter. The Viking biology experiments might test this hypothesis.

  15. Martian physical properties experiments: The Viking Mars Lander

    USGS Publications Warehouse

    Shorthill, R.W.; Hutton, R.E.; Moore, H.J.; Scott, R.F.

    1972-01-01

    Current data indicate that Mars, like the Earth and Moon, will have a soil-like layer. An understanding of this soil-like layer is an essential ingredient in understanding the Martian ecology. The Viking Lander and its subsystems will be used in a manner similar to that used by Sue Surveyor program to define properties of the Martian "soil". Data for estimates of bearing strength, cohesion, angle of internal friction, porosity, grain size, adhesion, thermal inertia, dielectric constants, and homogeneity of the Martian surface materials will be collected. ?? 1972.

  16. Evidence for a Second Martian Dynamo from Electron Reflection Magnetometry

    NASA Technical Reports Server (NTRS)

    Lillis, R. J.; Manga, M.; Mitchell, D. L.; Lin, R. P.; Acuna, M. H.

    2005-01-01

    Present-day Mars does not possess an active core dynamo and associated global magnetic field. However, the discovery of intensely magnetized crust in Mars Southern hemisphere implies that a Martian dynamo has existed in the past. Resolving the history of the Martian core dynamo is important for understanding the evolution of the planet's interior. Moreover, because the global magnetic field provided by an active dynamo can shield the atmosphere from erosion by the solar wind, it may have influenced past Martian climate. Additional information is included in the original extended abstract.

  17. History of Martian volatiles - Implications for organic synthesis.

    NASA Technical Reports Server (NTRS)

    Fanale, F. P.

    1971-01-01

    A theoretical reconstruction of the history of Martian volatiles indicates that Mars probably possessed a substantial reducing atmosphere at the outset of its history, and that its present tenuous and more oxidized atmosphere is the result of extensive chemical evolution. As a consequence, it is probable that Martian atmospheric chemical conditions, now hostile with respect to abiotic organic synthesis in the gas phase, were initially favorable. Evidence indicating the chronology and degradational history of Martian surface features, surface mineralogy, bulk volatile content, internal mass distribution, and thermal history suggests that Mars catastrophically developed a substantial reducing atmosphere as the result of rapid accretion.

  18. CO2: Adsorption on palagonite and the Martian regolith

    NASA Technical Reports Server (NTRS)

    Zent, Aaron P.; Fanale, Fraser P.; Postawko, Susan E.

    1987-01-01

    Possible scenarios for the evolution of the Martian climate are discussed. In the interest of determining an upper limit on the absorptive capacity of the Martian regolith, researchers examined the results of Fanale and Cannon (1971, 1974) for CO2 adsorption on nontronite and basalt. There appeared to be a strong proportionality between the capacity of the absorbent and its specific surface area. A model of the Martian climate is given that allows the researchers to make some estimates of exchangeable CO2 abundances.

  19. The Martian highland paterae: Evidence for explosive volcanism on Mars

    NASA Technical Reports Server (NTRS)

    Crown, David A.; Greeley, Ronald

    1988-01-01

    The Martian surface exhibits numerous volcanic landforms displaying great diversity in size, age, and morphology. Most research regarding Martian volcanology has centered around effusive basaltic volcanism, including analyses of individual lava flows, extensive lava plains, and large shield volcanoes. These studies were hindered by a lack of definitive morphologic criteria for the remote identification of ash deposits. Knowledge of the abundances, ages, and geologic settings of explosive volcanic deposits on Mars is essential to a comprehensive understanding of the evolution of the Martian surface, with implications for the evolution of the lithosphere and atmosphere as well as the histories of specific volcanic centers and provinces.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  1. Remote sensing of the Martian surface

    NASA Technical Reports Server (NTRS)

    Jakosky, Bruce M.; Henderson, Bradley G.; Randall, Cora E.; Alexander, M. Joan; Mccollom, Thomas M.

    1991-01-01

    Researchers investigated the physical properties of the Martian surface as inferred from a combination of orbiting and earth-based remote sensing observations and in-situ observations. This approach provides the most detailed and self-consistent view of the global and regional nature of the surface. Results focus on the areas of modeling the diurnal variation of the surface temperature of Mars, incorporating the effects of atmospheric radiation, with implications for the interpretation of surface thermal inertia; modeling the thermal emission from particulate surfaces, with application to observations of the surfaces of the Earth, Moon, and Mars; modeling the reflectance spectrum of Mars in an effort to understand the role of particle size in the difference between the bright and dark regions; and determining the slope properties of different terrestrial surfaces and comparing them with planetary slopes derived from radar observations.

  2. Evidence for life in a martian meteorite?

    PubMed

    McSween, H Y

    1997-07-01

    The controversial hypothesis that the ALH84001 meteorite contains relics of ancient martian life has spurred new findings, but the question has not yet been resolved. Organic matter probably results, at least in part, from terrestrial contamination by Antarctic ice meltwater. The origin of nanophase magnetites and sulfides, suggested, on the basis of their sizes and morphologies, to be biogenic remains contested, as does the formation temperature of the carbonates that contain all of the cited evidence for life. The reported nonfossils may be magnetite whiskers and platelets, probably grown from a vapor. New observations, such as the possible presence of biofilms and shock metamorphic effects in the carbonates, have not yet been evaluated. Regardless of the ultimate conclusion, this controversy continues to help define strategies and sharpen tools that will be required for a Mars exploration program focused on the search for life. PMID:11541665

  3. Rover's Wheel Churns Up Bright Martian Soil

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel.

    The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life.

    Spirit acquired this mosaic with the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. The view presented here is an approximately true-color rendering.

  4. Elemental composition of the Martian crust.

    PubMed

    McSween, Harry Y; Taylor, G Jeffrey; Wyatt, Michael B

    2009-05-01

    The composition of Mars' crust records the planet's integrated geologic history and provides clues to its differentiation. Spacecraft and meteorite data now provide a global view of the chemistry of the igneous crust that can be used to assess this history. Surface rocks on Mars are dominantly tholeiitic basalts formed by extensive partial melting and are not highly weathered. Siliceous or calc-alkaline rocks produced by melting and/or fractional crystallization of hydrated, recycled mantle sources, and silica-poor rocks produced by limited melting of alkali-rich mantle sources, are uncommon or absent. Spacecraft data suggest that martian meteorites are not representative of older, more voluminous crust and prompt questions about their use in defining diagnostic geochemical characteristics and in constraining mantle compositional models for Mars. PMID:19423810

  5. Elemental composition of the Martian crust.

    PubMed

    McSween, Harry Y; Taylor, G Jeffrey; Wyatt, Michael B

    2009-05-01

    The composition of Mars' crust records the planet's integrated geologic history and provides clues to its differentiation. Spacecraft and meteorite data now provide a global view of the chemistry of the igneous crust that can be used to assess this history. Surface rocks on Mars are dominantly tholeiitic basalts formed by extensive partial melting and are not highly weathered. Siliceous or calc-alkaline rocks produced by melting and/or fractional crystallization of hydrated, recycled mantle sources, and silica-poor rocks produced by limited melting of alkali-rich mantle sources, are uncommon or absent. Spacecraft data suggest that martian meteorites are not representative of older, more voluminous crust and prompt questions about their use in defining diagnostic geochemical characteristics and in constraining mantle compositional models for Mars.

  6. Simulation of Martian dust accumulation on surfaces

    NASA Technical Reports Server (NTRS)

    Perez-Davis, Marla E.; Gaier, James R.; Kress, Robert; Grimalda, Justus

    1990-01-01

    Future NASA space missions include the possibility of manned landings and exploration of Mars. Environmental and operational constraints unique to Mars must be considered when selecting and designing the power system to be used on the Mars surface. A technique is described which was developed to simulate the deposition of dust on surfaces. Three kinds of dust materials were studied: aluminum oxide, basalt, and iron oxide. The apparatus was designed using the Stokes and Stokes-Cunningham law for particle fallout, with additional consideration given to particle size and shape. Characterization of the resulting dust films on silicon dioxide, polytetrafluoroethylene, indium tin oxide, diamondlike carbon, and other surfaces are discussed based on optical transmittance measurements. The results of these experiments will guide future studies which will consider processes to remove the dust from surfaces under Martian environmental conditions.

  7. Thermally distinct ejecta blankets from Martian craters

    NASA Astrophysics Data System (ADS)

    Betts, B. H.; Murray, B. C.

    1993-06-01

    A study of Martian ejecta blankets is carried out using the high-resolution thermal IR/visible data from the Termoskan instrument aboard Phobos '88 mission. It is found that approximately 100 craters within the Termoskan data have an ejecta blanket distinct in the thermal infrared (EDITH). These features are examined by (1) a systematic examination of all Termoskan data using high-resolution image processing; (2) a study of the systematics of the data by compiling and analyzing a data base consisting of geographic, geologic, and mormphologic parameters for a significant fraction of the EDITH and nearby non-EDITH; and (3) qualitative and quantitative analyses of localized regions of interest. It is noted that thermally distinct ejecta blankets are excellent locations for future landers and remote sensing because of relatively dust-free surface exposures of material excavated from depth.

  8. Impact Crater Deposits in the Martian Highlands

    NASA Technical Reports Server (NTRS)

    Mest, S. C.; Crown, D. a.

    2005-01-01

    The martian highlands of Noachis Terra (20-30 deg S, 20-50 deg E), Tyrrhena Terra (0-30 deg S, 50- 100 deg E) and Terra Cimmeria (0-60 deg S, 120-170 deg E) preserve long and complex histories of degradation, but the relative effects of such factors as fluvial, eolian, and mass wasting processes have not been well constrained. The effects of this degradation are best observed on large (D greater than 10 km) impact craters that characterize the ancient highlands. Some craters exhibit distinct interior deposits, but precise origins of these deposits are enigmatic; infilling may occur by sedimentary (e.g., fluvial, lacustrine, eolian), mass wasting and (or) volcanic processes.

  9. Infrared Spectroscopy of Carbonates and Martian Exobiology

    NASA Astrophysics Data System (ADS)

    Blanco, Armando; Delia, Marcella; Fonti, Sergio; Licchelli, Domenico; Marzo, Giuseppe A.; Orofino, Vincenzo

    Searching for traces of extinct and/or extant life on the surface of Mars is one of the major objectives for remote-sensing and in-situ exploration of the planet. In a recent paper we have studied the infrared (IR) spectral modifications induced by thermal processing on differently preserved carbonate fossils, in order to discriminate them from their abiotic counterparts. The main conclusion of the study has been that terrestrial fossils after a billion years are so altered that it becomes impossible to trace their biotic origin. Since it is reasonable to assume that the putative Martian fossils should be at least 3.5 billions years old, this would imply that our spectroscopic method could not be able to detect them, if their degradation rate were the same as that we have found in usual conditions for the terrestrial fossils. However, due to the different climate evolution of the two planets, there is the possibility of having two different degradation rates, much lower for Mars than for Earth. In this work we show that our method is quite effective for fossils collected in protective layers of clays and that IR spectroscopy, coupled with thermal processing, can be a useful tool for discriminating between abiotic and biotic (fossil) carbonate samples collected on the Martian surface especially in phyllosilicate-rich regions such as Mawrth Vallis. Further work is currently done in our laboratory on various samples collected from carbonate sediments of the Late Miocene (Messinian) Calcare di Base Formation in northern Calabria (Italy), in order to study their origin.

  10. Exogenous carbonaceous matter in ancient martian sediments

    NASA Astrophysics Data System (ADS)

    Mojzsis, S. J.; Abramov, O.; Kereszturi, A.

    2015-12-01

    We re-evaluate the early evolution of an organic-matter rich (~10 wt. %) interplanetary dust particle flux to early Mars. Our work builds upon physical models that rely on plausible sources of exogenous debris and their dynamical rates of decay, the martian cratering record, and preservation of Noachian-Hesperian sedimentary units that have the potential to host organics. Post primary-accretionary scenarios that would have delivered abundant exogenous carbon to Mars can be imagined in two ways: a simple exponential decay with an approximately 100 Myr half-life, or as a "Sawtooth" timeline characterized by both faster-than-exponential decay from primary accretion and reduced total delivered mass. Indications are that a late bombardment spike was superposed on an otherwise broadly monotonic decline from primary accretion, of which two types are explored: a classical "Late Heavy Bombardment" (LHB) peak of impactors centered at ca. 3950 Ma and lasting 100 Myr, and a protracted bombardment typified by a sudden increase in impactor flux at ca. 4240-4100 Ma with a correspondingly longer decay time (400 Myr). Numerical models for each of the four bombardment scenarios explored in this work shows that exogenous organic matter could be a significant component of Noachian (ca. 4200-3700 Ma) and pre-Noachian (4500-4200 Ma) sediments. The discovery of organic-matter in martian sediments will be obfuscated by material of extra-areological origin. We predict that an earmark for the origin of this carbon would be correlated siderophile element abundances (e.g. Ni, Cr, and the platinoids). A time-dependent compositional relationship of C:HSEs would allow us to derive a chemochronology for pre-Hesperian (pre-3700 Ma) sedimentary units.

  11. Martian north polar cap summer water cycle

    NASA Astrophysics Data System (ADS)

    Brown, Adrian J.; Calvin, Wendy M.; Becerra, Patricio; Byrne, Shane

    2016-10-01

    A key outstanding question in Martian science is "are the polar caps gaining or losing mass and what are the implications for past, current and future climate?" To address this question, we use observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of the north polar cap during late summer for multiple Martian years, to monitor the summertime water cycle in order to place quantitative limits on the amount of water ice deposited and sublimed in late summer. We establish here for the first time the summer cycle of water ice absorption band signatures on the north polar cap. We show that in a key region in the interior of the north polar cap, the absorption band depths grow until Ls = 120, when they begin to shrink, until they are obscured at the end of summer by the north polar hood. This behavior is transferable over the entire north polar cap, where in late summer regions 'flip' from being net sublimating into net condensation mode. This transition or 'mode flip' happens earlier for regions closer to the pole, and later for regions close to the periphery of the cap. The observations and calculations presented herein estimate that on average a water ice layer ∼70 microns thick is deposited during the Ls = 135-164 period. This is far larger than the results of deposition on the south pole during summer, where an average layer 0.6-6 microns deep has been estimated by Brown et al. (2014) Earth Planet. Sci. Lett., 406, 102-109.

  12. Possible Meteorites in the Martian Hills

    NASA Technical Reports Server (NTRS)

    2006-01-01

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

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

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

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

  13. Comprehensive analysis of glaciated martian crater Greg

    NASA Astrophysics Data System (ADS)

    Hartmann, William K.; Ansan, Veronique; Berman, Daniel C.; Mangold, Nicolas; Forget, François

    2014-01-01

    The 66-km diameter martian crater, Greg, east of Hellas, hosts various distinctive features, including dendritic valleys filled with chevron-textured masses (south wall), and lobate tongues a few kilometers long (north wall). We analyze these features by various quantitative techniques to illuminate martian geologic and climatic history. Crater retention model ages indicate that Greg is at least 1-3 Gy old, but surface layers of mantles and glacial features are orders of magnitude younger. Properties of the dendritic valleys, combined with climate models, suggest that fluvial activity began under a thicker, warmer atmosphere, soon after the crater's formation. The oldest exposed fluvial systems have surface crater retention ages of a few hundred My, indicating runoff in recent geologic time. Much of Greg is covered by ice-rich mantle deposits, for which we infer gradual accumulation and depths of order 30-85 m; they mask pre-existing landforms. The lobate tongues are interpreted as glaciers with mean slope of 10.2 ± 2.3° and average thickness of 33 ± 19 m. Our calculations and data suggest that these glaciers were originally ice-rich and that their surface layers have been depleted by volatile loss. The glaciers probably formed when ice-rich mantle deposits reached critical thickness and flowed downhill. The top 5-10 m of the mantle and glaciers show crater survival times of order a few My to ˜15 My, which, remarkably, is the time since the last 1-4 episodes of obliquity >45°. Global climate models affirm that Greg lies in one of two non-polar areas with extremes of ice deposition during high-obliquity epochs. This match with observations supports the use of such models in studies of planetary climate change.

  14. Stability of clathrate hydrates in Martian crust

    NASA Astrophysics Data System (ADS)

    Gloesener, Elodie; Karatekin, Özgür; Dehant, Véronique

    2014-05-01

    Clathrate hydrates are crystalline compounds constituted by cages formed by hydrogen-bonded water molecules inside of which guest gas molecules are trapped. These materials are typically stable at high pressure and low temperature and are present on Earth mainly in marine sediments and in permafrost. Moreover, clathrate hydrates are expected to exist on celestial bodies like the icy moons Titan, Europa or Enceladus. Current conditions in the Martian crust are favourable to the presence of clathrate hydrates. In this study, we focused on the stability of methane and carbon dioxide clathrates in the Martian crust. We coupled the stability conditions of clathrates with a 1D thermal model in order to obtain the variations of the clathrate stability zone in the crust of Mars with time and for different crust compositions. Indeed, the type of soil directly controls the geothermal conditions and therefore the depth of clathrates formation. Unconsolidated soil acts as a thermal insulator and prevents the clathrates formation in the crust except on a small part of a few tens of meters thick. In contrast, sandstone or ice-cemented soil allows the clathrates formation with a stability zone of several kilometers. This is explained by the fact that they evacuate heat more efficiently and thus maintain lower temperatures. We also studied the stability zone of clathrates formed from a mixture of methane and hydrogen sulphide as well as from a mixture of methane and nitrogen. Contrary to the addition of N2, the addition of H2S to CH4 clathrates extends the stability zone and thus brings it closer to the surface. Therefore, mixed clathrates CH4-H2S will be more easily destabilized by changes in surface temperature than CH4 clathrates.

  15. A photochemical model of the martian atmosphere.

    PubMed

    Nair, H; Allen, M; Anbar, A D; Yung, Y L; Clancy, R T

    1994-09-01

    The factors governing the amounts of CO, O2, and O3 in the martian atmosphere are investigated using a minimally constrained, one-dimensional photochemical model. We find that the incorporation of temperature-dependent CO2 absorption cross sections leads to an enhancement in the water photolysis rate, increasing the abundance of OH radicals to the point where the model CO abundance is smaller than observed. Good agreement between models and observations of CO, O2, O3, and the escape flux of atomic hydrogen can be achieved, using only gas-phase chemistry, by varying the recommended rate constants for the reactions CO + OH and OH + HO2 within their specified uncertainties. Similar revisions have been suggested to resolve discrepancies between models and observations of the terrestrial mesosphere. The oxygen escape flux plays a key role in the oxygen budget on Mars; as inferred from the observed atomic hydrogen escape, it is much larger than recent calculations of the exospheric escape rate for oxygen. Weathering of the surface may account for the imbalance. Quantification of the escape rates of oxygen and hydrogen from Mars is a worthwhile objective for an upcoming martian upper atmospheric mission. We also consider the possibility that HOx radicals may be catalytically destroyed on dust grains suspended in the atmosphere. Good agreement with the observed CO mixing ratio can be achieved via this mechanism, but the resulting ozone column is much higher than the observed quantity. We feel that there is no need at this time to invoke heterogeneous processes to reconcile models and observations. PMID:11539176

  16. Martian polar vortices: Comparison of reanalyses

    NASA Astrophysics Data System (ADS)

    Waugh, D. W.; Toigo, A. D.; Guzewich, S. D.; Greybush, S. J.; Wilson, R. J.; Montabone, L.

    2016-09-01

    The structure and evolution of the Martian polar vortices is examined using two recently available reanalysis systems: version 1.0 of the Mars Analysis Correction Data Assimilation (MACDA) and a preliminary version of the Ensemble Mars Atmosphere Reanalysis System (EMARS). There is quantitative agreement between the reanalyses in the lower atmosphere, where Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) data are assimilated, but there are differences at higher altitudes reflecting differences in the free-running general circulation model simulations used in the two reanalyses. The reanalyses show similar potential vorticity (PV) structure of the vortices: There is near-uniform small PV equatorward of the core of the westerly jet, steep meridional PV gradients on the polar side of the jet core, and a maximum of PV located off of the pole. In maps of 30 sol mean PV, there is a near-continuous elliptical ring of high PV with roughly constant shape and longitudinal orientation from fall to spring. However, the shape and orientation of the vortex varies on daily time scales, and there is not a continuous ring of PV but rather a series of smaller scale coherent regions of high PV. The PV structure of the Martian polar vortices is, as has been reported before, very different from that of Earth's stratospheric polar vortices, but there are similarities with Earth's tropospheric vortices which also occur at the edge of the Hadley Cell, and have near-uniform small PV equatorward of the jet, and a large increase of PV poleward of the jet due to increased stratification.

  17. Volatile trace elements in and cluster analysis of Martian meteorites

    NASA Astrophysics Data System (ADS)

    Wang, Ming-Sheng; Mokos, Jennifer A.; Lipschutz, Michael E.

    1998-07-01

    We report data for 15 mainly volatile trace elements (Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Sb, Se, Te, Tl, U, Zn) by radiochemical neutron activation analysis (RNAA) in whole-rock samples of 5 martian meteorites which, with 7 others studied earlier, completes the 12-member martian meteorite suite. Nearly all of these elements exhibit highly variable compositional continua and are richer in the martian suite compared with other basaltic meteorites. From cluster analysis, we find that the clustering of subtypes based on these elements is virtually identical to that based on contents of major refractory elements and mineralogic/petrographic characteristics, implying that each source region on Mars was closed to volatile transport. Martian meteorite data can be used to infer volatile element contents in that planet.

  18. Weathering and Secondary Minerals in the Martian Meteorite Shergotty

    NASA Technical Reports Server (NTRS)

    Wentworth, Susan J.; Thomas-Keprta, Kathie L.; McKay, David S.

    2000-01-01

    The Shergotty martian meteorite contains weathering features and secondary minerals much like those in Nakhla, including secondary silicates, NaCl, and Ca-sulfate. It is likely that the weathering occurred on Mars.

  19. 'Bounce' and Martian Meteorite of the Same Mold

    NASA Technical Reports Server (NTRS)

    2004-01-01

    These two sets of bar graphs compare the elemental compositions of six martian rocks: 'Bounce,' located at Meridiani Planum; EETA79001-B, a martian meteorite found in Antarctica in 1979; a rock found at the Mars Pathfinder landing site; Shergotty, a martian meteorite that landed in India in 1865; 'Adirondack,' located at Gusev Crater; and 'Humphrey,' also located at Gusev Crater. The graph on the left compares magnesium/iron ratios in the rocks, and the graph on the right compares aluminum/calcium ratios. The results illustrate the diversity of rocks on Mars and indicate that Bounce probably shares origins with the martian meterorite EETA79001-B. The Bounce data was taken on sol 68 by the alpha particle X-ray spectrometer on Mars Exploration Rover Opportunity.

  20. Mobility of icy sand packs, with application to Martian permafrost

    USGS Publications Warehouse

    Durham, W.B.; Pathare, A.V.; Stern, L.A.; Lenferink, H.J.

    2009-01-01

    [1] The physical state of water on Mars has fundamental ramifications for both climatology and astrobiology. The widespread presence of "softened" Martian landforms (such as impact craters) can be attributed to viscous creep of subsurface ground ice. We present laboratory experiments designed to determine the minimum amount of ice necessary to mobilize topography within Martian permafrost. Our results show that the jammed-to-mobile transition of icy sand packs neither occurs at fixed ice content nor is dependent on temperature or stress, but instead correlates strongly with the maximum dry packing density of the sand component. Viscosity also changes rapidly near the mobility transition. The results suggest a potentially lower minimum volatile inventory for the impact-pulverized megaregolith of Mars. Furthermore, the long-term preservation of partially relaxed craters implies that the ice content of Martian permafrost has remained close to that at the mobility transition throughout Martian history. Copyright 2009 by the American Geophysical Union.

  1. Crater Floor Fractures: Probes Into Habitable Martian Environments

    NASA Astrophysics Data System (ADS)

    Thomas, R. J.; Hynek, B. M.

    2016-05-01

    Geologic and spectral analysis of martian impact craters reveals the potential for floor-fractures with a aqueous/volcanic genesis to probe into both ancient surface and Hesperian-aged deep habitable environments.

  2. The Effect of Dust on the Martian Polar Vortices

    NASA Astrophysics Data System (ADS)

    Guzewich, S. D.; Toigo, A. D.; Waugh, D. W.

    2016-09-01

    We examine transient warming events of the martian north polar winter vortex in Mars Climate Sounder observations and MarsWRF general circulation model simulations caused by increased atmospheric dust opacity.

  3. Workshop on Evolution of Martian Volatiles. Part 2

    NASA Technical Reports Server (NTRS)

    Jakosky, B. (Editor); Treiman, A. (Editor)

    1996-01-01

    Different aspects of martian science are discussed. Topics covered include: early Mars volatile inventory, evolution through time, geological influences, present atmospheric properties, soils, exobiology, polar volatiles, and seasonal and diurnal cycles

  4. Contradictory clues as to the origin of the Martian moons

    NASA Technical Reports Server (NTRS)

    Burns, Joseph A.

    1992-01-01

    The meager available information that is pertinent to the origin and evolution of the Martian satellites is contradictory. The known physical properties of the Martian moons (density, albedo, color and spectral reflectivity) are similar to those of many C-type asteroids, the dark 'carbonaceous' objects abundant in the outer belt but scarce near Mars; thus this line of physical evidence suggests that Phobos and Deimos are captured bodies. In contrast, calculated histories of orbital evolution due to tides in the planet and in the satellites indicate that these small craggy moons originated on nearly circular, uninclined orbits not far from their current positions; hence dynamicists prefer an origin in circum-Martian orbit. Ways are described in which these apparently contradictory viewpoints may be reconciled, although a definitive answer to the origin of the Martian satellites will almost surely have to await in situ measurements.

  5. A System of Systems Approach for Martian Exploration

    NASA Astrophysics Data System (ADS)

    Semrud, E. B.; Evans, B. W.; Fredericks, B.; Wells, D.

    2012-06-01

    A system of systems is designed for characterization of the Martian atmosphere and exploration of lava tubes in preparation for human colonization. Multiple expendable deployable sensor packages ensure mission success with a high level of redundancy.

  6. Amino Acids in the Antarctic Martian Meteorite MIL03346

    NASA Technical Reports Server (NTRS)

    Glavin, D. P.; Aubrey, A.; Dworkin, J. P.; Botta, O.; Bada, J. L.

    2005-01-01

    The report by McKay et al. that the Martian meteorite ALH84001 contains evidence for life on Mars remains controversial. Of central importance is whether ALH84001 and other Antarctic Martian meteorites contain endogenous organic compounds. In any investigation of organic compounds possibly derived from Mars it is important to focus on compounds that play an essential role in biochemistry as we know it and that have properties such as chirality which can be used to distinguish between biotic versus abiotic origins. Amino acids are one of the few compounds that fulfill these requirements. Previous analyses of the Antarctic Martian meteorites ALH84001 and EETA79001 have shown that these meteorites contain low levels of terrestrial amino acid contamination derived from Antarctic ice meltwater. Here we report preliminary amino acid investigations of a third Antarctic Martian meteorite MIL03346 which was discovered in Antarctica during the 2003-04 ANSMET season. Additional information is included in the original extended abstract

  7. Atmospheric CO2 Supersaturation Observed in the Martian Polar Nights

    NASA Astrophysics Data System (ADS)

    Noguchi, K.; Kuroda, T.; Hayashi, H.

    2016-09-01

    The present study shows the spatio-temporal distribution of the occurrence of CO2 supersaturation in the martian atmosphere by using the Mars Global Surveyor radio occultation data. We also compare the results with numerical simulation results.

  8. Lunar and Planetary Science XXXV: Martian Meteorites: Petrology

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Martian Meteorites: Petrology: included the following reports:Volatile Behavior in Lunar and Terrestrial Basalts During Shock: Implications for Martian Magmas; Problems with a Low-Pressure Tholeiitic Magmatic History for the Chassigny Dunite; Fast Cooling History of the Chassigny Martian Meteorite; Rehomogenized Interstitial and Inclusion Melts in Lherzolitic Shergottite ALH 77005: Petrologic Significance; Compositional Controls on the Formation of Kaersutite Amphibole in Shergottite Meteorites; Chemical Characteristics of an Olivine-Phyric Shergottite, Yamato 980459; Pb-Hf-Sr-Nd Isotopic Systematics and Age of Nakhlite NWA 998; Noble Gases in Two Samples of EETA 79001 (Lith. A); Experimental Constraints on the Iron Content of the Martian Mantle; and Mars as the Parent Body for the CI Carbonaceous Chondrites: New Data.

  9. Sulphur Spring: Busy Intersection and Possible Martian Analogue

    NASA Technical Reports Server (NTRS)

    Nankivell, A.; Andre, N.; Thomas-Keprta, K.; Allen, C.; McKay, D.

    2000-01-01

    Life in extreme environments exhibiting conditions similar to early Earth and Mars, such as Sulphur Spring, may harbor microbiota serving as both relics from the past as well as present day Martian analogues.

  10. Evidence for explosive volcanic density currents on certain Martian volcanoes

    NASA Technical Reports Server (NTRS)

    Reimers, C. E.; Komar, P. D.

    1979-01-01

    The morphologies of certain of the smaller Martian volcanoes are discussed as possible results of explosive volcanic density currents. An examination of newly-photographed flank and caldera features of the Martian volcanoes Ceraunius Tholus, Uranius Tholus, Uranius Patera and Hecates Tholus, including steep slope angles, Krakatoa-type caldera morphologies, erosional features (radial channels and anastamosing gullies) and constructional features (blanketed flanks and possible lava deltas) reveals their similarity to terrestrial cones and composite volcanoes such as Barcena Volcano. Crater age data from the surface of Martian domes and shields indicates that such explosive activity occurred more frequently early in Martian geologic history, consistent with the view that the volcanic density currents were base surges rather than nuees ardentes, with the melting of permafrost supplying the water required in base surge generation.

  11. Martian Atmospheric Methane Plumes from Meteor Shower Infall: A Hypothesis

    NASA Astrophysics Data System (ADS)

    Fries, M.; Christou, A.; Archer, D.; Conrad, P.; Cooke, W.; Eigenbrode, J.; ten Kate, I. L.; Matney, M.; Niles, P.; Sykes, M.; Steele, A.; Treiman, A.

    2016-09-01

    Methane plumes in the martian atmosphere were previously reported, but their source remains a mystery. We hypothesize a meteor shower source, as we find a correlation between Mars/cometary orbit encounters and detections of plumes.

  12. Dune-like dynamic of Martian Aeolian large ripples

    NASA Astrophysics Data System (ADS)

    Silvestro, S.; Vaz, D. A.; Yizhaq, H.; Esposito, F.

    2016-08-01

    Martian dunes are sculpted by meter-scale bed forms, which have been interpreted as wind ripples based on orbital data. Because aeolian ripples tend to orient and migrate transversely to the last sand-moving wind, they have been widely used as wind vanes on Earth and Mars. In this report we show that Martian large ripples are dynamically different from Earth's ripples. By remotely monitoring their evolution within the Mars Science Laboratory landing site, we show that these bed forms evolve longitudinally with minimal lateral migration in a time-span of ~ six terrestrial years. Our observations suggest that the large Martian ripples can record more than one wind direction and that in certain cases they are more similar to linear dunes from a dynamic point of view. Consequently, the assumption of the transverse nature of the large Martian ripples must be used with caution when using these features to derive wind directions.

  13. Experimental Confirmation of the Volatility of Germanium in Martian Basalts

    NASA Astrophysics Data System (ADS)

    Humayun, M.; DiFrancesco, N.; Ustunisik, G.

    2016-08-01

    Experimental degassing of a synthetic martian basalt doped with Ge and Zn resulted in nearly total loss of both elements after 6 hours of heating, implying that the Ge depletion in shergottites is complemented by Ge excesses in sedimentary rocks.

  14. Alteration of Sedimentary Clasts in Martian Meteorite Northwest Africa 7034

    NASA Technical Reports Server (NTRS)

    McCubbin, F. M.; Tartese, R.; Santos, A. R.; Domokos, G.; Muttik, N.; Szabo, T.; Vazquez, J.; Boyce, J. W.; Keller, L. P.; Jerolmack, D. J.; Anand, M.; Moser, D. E.; Delhaye, T.; Shearer, C. K.; Agee, C. B.

    2014-01-01

    The martian meteorite Northwest Africa (NWA) 7034 and pairings represent the first brecciated hand sample available for study from the martian surface [1]. Detailed investigations of NWA 7034 have revealed substantial lithologic diversity among the clasts [2-3], making NWA 7034 a polymict breccia. NWA 7034 consists of igneous clasts, impact-melt clasts, and "sedimentary" clasts represented by prior generations of brecciated material. In the present study we conduct a detailed textural and geochemical analysis of the sedimentary clasts.

  15. The Spokane flood controversy and the Martian outflow channels

    NASA Technical Reports Server (NTRS)

    Baker, V. R.

    1978-01-01

    The controversy over Bretz's hypothesis concerning the cataclysmic Spokane flood is discussed. Attention is directed to similarities between the Channeled Scabland of Washington and some Martian land features considered to be catastrophic flood channels. Characteristics of the enormous plexus of proglacial stream channels eroded into the loess and basalt of the Columbia Plateau in eastern Washington are described. The controversiality of the suggestion that a catastrophic flood is responsible for the Martian features is considered with respect to the Spokane flood controversy.

  16. Biological Agents

    MedlinePlus

    ... to Z Index Contact Us FAQs What's New Biological Agents This page requires that javascript be enabled ... and Health Topics A-Z Index What's New Biological agents include bacteria, viruses, fungi, other microorganisms and ...

  17. Refining Martian Ages and Understanding Geological Processes From Cratering Statistics

    NASA Technical Reports Server (NTRS)

    Hartmann, William K.

    2005-01-01

    Senior Scientist William K. Hartman presents his final report on Mars Data Analysis Program grant number NAG5-12217: The third year of the three-year program was recently completed in mid-2005. The program has been extremely productive in research and data analysis regarding Mars, especially using Mars Global Surveyor and Mars Odyssey imagery. In the 2005 alone, three papers have already been published, to which this work contributed.1) Hartmann, W. K. 200.5. Martian cratering 8. Isochron refinement and the history of Martian geologic activity Icarus 174, 294-320. This paper is a summary of my entire program of establishing Martian chronology through counts of Martian impact craters. 2) Arfstrom, John, and W. K. Hartmann 2005. Martian flow features, moraine-like rieges, and gullies: Terrestrial analogs and interrelationships. Icarus 174,32 1-335. This paper makes pioneering connections between Martian glacier-like features and terrestrial glacial features. 3) Hartmann, W.K., D. Winterhalter, and J. Geiss. 2005 Chronology and Physical Evolution of Planet Mars. In The Solar System and Beyond: Ten Years of ISSI (Bern: International Space Science Institute). This is a summary of work conducted at the International Space Science Institute with an international team, emphasizing our publication of a conference volume about Mars, edited by Hartmann and published in 2001.

  18. [Meteoritics and mineralogy on possible ancient Martian life].

    PubMed

    Tsuchiyama, A

    1996-12-01

    Possible relic biogenic activity in martian meteorite ALH84001 was proposed by McKay et al. (Science, 273, 924-930, 1996). This ancient meteorite of 4.5 billion years old contains abundant carbonates as secondary minerals precipitated from a fluid on the martian surface. They showed the following lines of evidence for the ancient life; (1) unique mineral compositions and biominerals, (2) polycyclic aromatic hydrocarbons (PAHs) in association with the carbonates, and (3) unique structures and morphologies typical of nanobacteria or microfossils. This review is divided into two parts; one is on the martian meteorites in general and ALH84001, which has many features unlike other martian meteorites, and the other is on mineralogical (biomineralogical) and geochemical features of the carbonates and microfossil-like structures. There is little doubt that ALH84001 is from Mars as well as eleven other SNC meteorites. However, the mineralogical and biomineralogical evidence for martian bacteria given by McKay et al. (1996) is controversial, and could be formed by non-biogenic processes. Thus, further study of ALH84001 and other martian meteorites is required. We also need to consider the future Mars mission especially sample return mission.

  19. [Meteoritics and mineralogy on possible ancient Martian life].

    PubMed

    Tsuchiyama, A

    1996-12-01

    Possible relic biogenic activity in martian meteorite ALH84001 was proposed by McKay et al. (Science, 273, 924-930, 1996). This ancient meteorite of 4.5 billion years old contains abundant carbonates as secondary minerals precipitated from a fluid on the martian surface. They showed the following lines of evidence for the ancient life; (1) unique mineral compositions and biominerals, (2) polycyclic aromatic hydrocarbons (PAHs) in association with the carbonates, and (3) unique structures and morphologies typical of nanobacteria or microfossils. This review is divided into two parts; one is on the martian meteorites in general and ALH84001, which has many features unlike other martian meteorites, and the other is on mineralogical (biomineralogical) and geochemical features of the carbonates and microfossil-like structures. There is little doubt that ALH84001 is from Mars as well as eleven other SNC meteorites. However, the mineralogical and biomineralogical evidence for martian bacteria given by McKay et al. (1996) is controversial, and could be formed by non-biogenic processes. Thus, further study of ALH84001 and other martian meteorites is required. We also need to consider the future Mars mission especially sample return mission. PMID:11540347

  20. MOC Views of Martian Solar Eclipses

    NASA Technical Reports Server (NTRS)

    1999-01-01

    [figure removed for brevity, see original site]

    The shadow of the martian moon, Phobos, has been captured in many recent wide angle camera views of the red planet obtained by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). Designed to monitor changes in weather and surface conditions, the wide angle cameras are also proving to be a good way to spot the frequent solar eclipses caused by the passage of Phobos between Mars and the Sun.

    The first figure (above), shows wide angle red (left), blue (middle), and color composite (right) views of the shadow of Phobos (elliptical feature at center of each frame) as it was cast upon western Xanthe Terra on August 26, 1999, at about 2 p.m.local time on Mars. The image covers an area about 250 kilometers (155 miles) across and is illuminated from the left. The meandering Nanedi Valles is visible in the lower right corner of the scene. Note the dark spots on three crater floors--these appear dark in the red camera image (left) but are barely distinguished in the blue image (middle), while the shadow is dark in both images. The spots on the crater floors are probably small fields of dark sand dunes.

    The second figure shows three samples of MOC's global image swaths, each in this case with a shadow of Phobos visible (arrow). The first scene (left) was taken on September 1, 1999, and shows the shadow of Phobos cast upon southern Elysium Planitia. The large crater with dark markings on its floor at the lower right corner is Herschel Basin. The second scene shows the shadow of Phobos cast upon northern Lunae Planum on September 8, 1999. Kasei Valles dominates the upper right and the deep chasms of Valles Marineris dominate the lower third of the September 8 image. The picture on the right shows the shadow of Phobos near the giant volcano, Olympus Mons (upper left), on September 25, 1999. Three other major volcanoes are visible from lower-center (Arsia Mons) and right-center (Pavonis Mons) to upper

  1. Using Wind Driven Tumbleweed Rovers to Explore Martian Gully Features

    NASA Technical Reports Server (NTRS)

    Antol, Jeffrey; Woodard, Stanley E.; Hajos, Gregory A.; Heldmann, Jennifer L.; Taylor, Bryant D.

    2004-01-01

    Gully features have been observed on the slopes of numerous Martian crater walls, valleys, pits, and graben. Several mechanisms for gully formation have been proposed, including: liquid water aquifers (shallow and deep), melting ground ice, snow melt, CO2 aquifers, and dry debris flow. Remote sensing observations indicate that the most likely erosional agent is liquid water. Debate concerns the source of this water. Observations favor a liquid water aquifer as the primary candidate. The current strategy in the search for life on Mars is to "follow the water." A new vehicle known as a Tumbleweed rover may be able to conduct in-situ investigations in the gullies, which are currently inaccessible by conventional rovers. Deriving mobility through use of the surface winds on Mars, Tumbleweed rovers would be lightweight and relatively inexpensive thus allowing multiple rovers to be deployed in a single mission to survey areas for future exploration. NASA Langley Research Center (LaRC) is developing deployable structure Tumbleweed concepts. An extremely lightweight measurement acquisition system and sensors are proposed for the Tumbleweed rover that greatly increases the number of measurements performed while having negligible mass increase. The key to this method is the use of magnetic field response sensors designed as passive inductor-capacitor circuits that produce magnetic field responses whose attributes correspond to values of physical properties for which the sensors measure. The sensors do not need a physical connection to a power source or to data acquisition equipment resulting in additional weight reduction. Many of the sensors and interrogating antennae can be directly placed on the Tumbleweed using film deposition methods such as photolithography thus providing further weight reduction. Concepts are presented herein for methods to measure subsurface water, subsurface metals, planetary winds and environmental gases.

  2. Using Wind Driven Tumbleweed Rovers to Explore Martian Gully Features

    NASA Technical Reports Server (NTRS)

    Antol, Jeffrey; Woodard, Stanley E.; Hajos, Gregory A.; Heldmann, Jennifer L.; Taylor, Bryant D.

    2005-01-01

    Gully features have been observed on the slopes of numerous Martian crater walls, valleys, pits, and graben. Several mechanisms for gully formation have been proposed, including: liquid water aquifers (shallow and deep), melting ground ice, snow melt, CO2 aquifers, and dry debris flow. Remote sensing observations indicate that the most likely erosional agent is liquid water. Debate concerns the source of this water. Observations favor a liquid water aquifer as the primary candidate. The current strategy in the search for life on Mars is to "follow the water." A new vehicle known as a Tumbleweed rover may be able to conduct in-situ investigations in the gullies, which are currently inaccessible by conventional rovers. Deriving mobility through use of the surface winds on Mars, Tumbleweed rovers would be lightweight and relatively inexpensive thus allowing multiple rovers to be deployed in a single mission to survey areas for future exploration. NASA Langley Research Center (LaRC) is developing deployable structure Tumbleweed concepts. An extremely lightweight measurement acquisition system and sensors are proposed for the Tumbleweed rover that greatly increases the number of measurements performed while having negligible mass increase. The key to this method is the use of magnetic field response sensors designed as passive inductor-capacitor circuits that produce magnetic field responses whose attributes correspond to values of physical properties for which the sensors measure. The sensors do not need a physical connection to a power source or to data acquisition equipment resulting in additional weight reduction. Many of the sensors and interrogating antennae can be directly placed on the Tumbleweed using film deposition methods such as photolithography thus providing further weight reduction. Concepts are presented herein for methods to measure subsurface water, subsurface metals, planetary winds and environmental gases.

  3. Identification of Iron-Bearing Phases on the Martian Surface and in Martian Meteorites and Analogue Samples by Moessbauer Spectroscopy

    NASA Technical Reports Server (NTRS)

    Klingelhoefer, G.; Agresti, D. G.; Schroeder, C.; Rodionov, D.; Yen, A.; Ming, Doug; Morris, Richard V.

    2007-01-01

    The Moessbauer spectrometers on the Mars Exploration Rovers (MER) Spirit (Gusev Crater) and Opportunity (Meridiani Planum) have each analyzed more than 100 targets during their ongoing missions (>1050 sols). Here we summarize the Fe-bearing phases identified to date and compare the results to Moessbauer analyses of martian meteorites and lunar samples. We use lunar samples as martian analogues because some, particularly the low-Ti Apollo 15 mare basalts, have bulk chemical compositions that are comparable to basaltic martian meteorites [1,2]. The lunar samples also provide a way to study pigeonite-rich samples. Pigeonite is a pyroxene that is not common in terrestrial basalts, but does often occur on the Moon and is present in basaltic martian meteorites

  4. Explaining the Birth of the Martian Moons

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    A new study examines the possibility that Marss two moons formed after a large body slammed into Mars, creating a disk of debris. This scenario might be the key to reconciling the moons orbital properties with their compositions.Conflicting EvidenceThe different orbital (left) and spectral (right) characteristics of the Martian moons in the three different formation scenarios. Click for a better look! Phobos and Deimoss orbital characteristics are best matched by formation around Mars (b and c), and their physical characteristics are best matched by formation in the outer region of an impact-generated accretion disk (rightmost panel of c). [Ronnet et al. 2016]How were Marss two moons, Phobos and Deimos, formed? There are three standing theories:Two already-formed, small bodies from the outer main asteroid belt were captured by Mars, intact.The bodies formed simultaneously with Mars, by accretion from the same materials.A large impact on Mars created an accretion disk of material from which the two bodies formed.Our observations of the Martian moons, unfortunately, provide conflicting evidence about which of these scenarios is correct. The physical properties of the moons low albedos, low densities are consistent with those of asteroids in our solar system, and are not consistent with Marss properties, suggesting that the co-accretion scenario is unlikely. On the other hand, the moons orbital properties low inclination, low eccentricity, prograde orbits are consistent with bodies that formed around Mars rather than being captured.In a recent study,a team of scientists led by Thomas Ronnet and Pierre Vernazza (Aix-Marseille University, Laboratory of Astrophysics of Marseille) has attempted to reconcile these conflictingobservations by focusing on the third option.Moons After a Large ImpactIn the thirdscenario, an impactor of perhaps a few percent of Marss mass smashed into Mars, forming a debris disk of hot material that encircled Mars. Perturbations in the disk then

  5. Impact activation of Martian permafrost: Numerical modeling

    NASA Astrophysics Data System (ADS)

    Ivanov, B.; Melosh, H. J.

    2011-12-01

    For the last decade the team of Dr. Elisabetta (Betty) Pierazzo (LPL+PSI) study physical and mechanical processes involved in impact melting of Martian permafrost. The idea is that on Mars large enough impact craters would start substantial hydrothermal activity underneath the crater for thousands of years (possibly for >1 Myr, if a crater is larger than about 200 km in diameter). Numerical efforts to predict the extent and time scale of hydrothermal activity in Martian impact craters have mostly relied on numerical simulations of impact cratering into uniform or layered ice-rock targets. We conduct a case modeling study of impact melting of permafrost on Mars to investigate the general thermal state of the rock layers modified in the formation of hyper-velocity impact craters. We model the formation of a mid-size crater, about 30 km in diameter, formed on target consisting of a mixture of large particles of H2O-ice and rock (something like ice lenses in rock fractures) and fine mix equilibrated in temperature with an ice/water content variable with depth. The model results indicate that for craters larger than about 30 km in diameter the onset of post-impact hydrothermal circulation is characterized by two stages: first, the formation of a mostly dry, hot central uplift, followed by water beginning to flow in and circulate through the initially dry and hot uplifted crustal rocks. The post-impact thermal field in the periphery of the crater is dependent on crater size: in mid-size craters, 30-50 km in diameter, crater walls are not strongly heated in the impact event, and even though ice present in the rock may initially be heated enough to melt, overall temperatures in the rock remain below melting, undermining the development of a crater-wide hydrothermal circulation. We speculate that salt deposition from supercritical water may occur immediately after impact in some locations before the normal water circulation starts. In larger craters, crater walls are heated

  6. Multiyear Simulations of the Martian Water Cycle with the Ames General Circulation Model

    NASA Technical Reports Server (NTRS)

    Haberle, R. M.; Schaeffer, J. R.; Nelli, S. M.; Murphy, J. R.

    2003-01-01

    Mars atmosphere is carbon dioxide dominated with non-negligible amounts of water vapor and suspended dust particles. The atmospheric dust plays an important role in the heating and cooling of the planet through absorption and emission of radiation. Small dust particles can potentially be carried to great altitudes and affect the temperatures there. Water vapor condensing onto the dust grains can affect the radiative properties of both, as well as their vertical extent. The condensation of water onto a dust grain will change the grain s fall speed and diminish the possibility of dust obtaining high altitudes. In this capacity, water becomes a controlling agent with regard to the vertical distribution of dust. Similarly, the atmosphere s water vapor holding capacity is affected by the amount of dust in the atmosphere. Dust is an excellent green house catalyst; it raises the temperature of the atmosphere, and thus, its water vapor holding capacity. There is, therefore, a potentially significant interplay between the Martian dust and water cycles. Previous research done using global, 3-D computer modeling to better understand the Martian atmosphere treat the dust and the water cycles as two separate and independent processes. The existing Ames numerical model will be employed to simulate the relationship between the Martian dust and water cycles by actually coupling the two cycles. Water will condense onto the dust, allowing the particle's radiative characteristics, fall speeds, and as a result, their vertical distribution to change. Data obtained from the Viking, Mars Pathfinder, and especially the Mars Global Surveyor missions will be used to determine the accuracy of the model results.

  7. Rocket dust storms and detached dust layers in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Spiga, Aymeric; Faure, Julien; Madeleine, Jean-Baptiste; Määttänen, Anni; Forget, François

    2013-04-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling that includes the transport of radiatively active dust to predict the evolution of a local dust storm monitored by OMEGA on board Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, rather than by latent heating as in moist convection on Earth. We propose to use the terminology "rocket dust storm," or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30-50 km). Combined to horizontal transport by large-scale winds, rocket dust storms produce detached layers of dust reminiscent of those observed with Mars Global Surveyor and Mars Reconnaissance Orbiter. Since nighttime sedimentation is less efficient than daytime convective transport, and the detached dust layers can convect during the daytime, these layers can be stable for several days. The peak activity of rocket dust storms is expected in low-latitude regions at clear seasons (late northern winter to late northern summer), which accounts for the high-altitude tropical dust maxima unveiled by Mars Climate Sounder. Dust-driven deep convection has strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.

  8. Brines and evaporites: analogs for Martian life

    NASA Astrophysics Data System (ADS)

    Mancinelli, R. L.; Fahlen, T. F.; Landheim, R.; Klovstad, M. R.

    2004-01-01

    Data from recent Mars missions suggest that Mars almost certainly had abundant liquid water on its surface at some time in the past. As a result, Mars has emerged as a key solar system target that could have harbored some form of life in the past, and which could perhaps still possess remnants of life in brine-containing permafrost. As Mars lost its atmosphere it became cold and dry. Any remaining water on the surface may have formed saline brine pockets within the permafrost. These brine pockets may either be an "oasis" for an extant Martian biota, or the last refuge of an extinct Martian biota. Eventually, these brine pockets would have dried to form evaporites. Evaporites are deposits that result from the evaporation of saline water, which on earth represent primarily halite (NaCl), gypsum, (CaSO 42H 2O), and anhydrite (CaSO 4). Evaporites that contain bacterial and algal assemblages exist on earth today and are well known in the fossil record. The most likely organism type to survive in a brine or evaporite on earth is a halophile. The objective of this study was to determine the potential of microbes to survive in frozen evaporites. Washed mid-log phase and stationary phase cultures of Haloarcula-G (a species isolated by us during a previous study) and Halobacterium salinarum were either suspended in brine (25% NaCl solution), dried, and then exposed to -20 or -80 °C. For comparison, cultures of Deinococcus radiodurans, Escherichia coli, and Pseudomonas fluorescens were treated similarly, except they were resuspended in 0.5% NaCl solution. Also, to mimic a brine pocket samples of washed mid-log phase cells of each organism were placed in an aqueous solution of 25% NaCl, or in their respective nutrient medium containing 25% NaCl. Periodically, samples of the cells were removed and tested for survival. Data from these experiments suggest that halophiles survive better than non-halophiles under low temperature conditions. These observations would suggest that

  9. Studies of the Martian Magnetic Field

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1998-01-01

    This report covers two awards: the first NAGW-2573 was awarded to enable participation in the Mars 94 mission that slipped to become the Mars 96 mission. Upon the unfortunate failure of Mars 96 to achieve its intended trajectory, the second grant was awarded to closeout the Mars 96 activities. Our initial efforts concentrated on assisting our colleagues: W. Riedler, K. Schwingenschuh, K. Gringanz, M. Verigin and Ye. Yeroshenko with advice on the development of the magnetic field portion of the investigation and to help them with test activities. We also worked with them to properly analyze the Phobos magnetic field and plasma data in order to optimize the return from the Mars 94/96 mission. This activity resulted in 18 papers on Mars scientific topics, and two on the instrumentation. One of these latter two papers was the last of the papers written, and speaks to the value of the closeout award. These 20 papers are listed in the attached bibliography. Because we had previously studied Venus and Titan and since it was becoming evident that the magnetic field was very weak, we compared the various properties of the Martian interaction with those of the analogous interactions at Venus and Titan while other papers simply analyzed the properties of the interaction as Phobos 2 observed them. One very interesting observation was the identification of ions picked up in the solar wind, originating in Mars neutral atmosphere. These had been predicted by our earlier observation of cyclotron waves at the proton gyrofrequency in the region upstream from Mars in the solar wind. Of course, the key question we addressed was that of the intrinsic or induced nature of the Martian magnetic field. We found little evidence for the former and much for the latter point of view. We also discussed the instrumentation planned for the Mars balloon and the instrumentation on the orbiter. In all these studies were very rewarding despite the short span of the Phobos data. Although they did not

  10. Meteoric ion layers in the Martian atmosphere.

    PubMed

    Whalley, Charlotte L; Plane, John M C

    2010-01-01

    Low-lying plasma layers have been observed sporadically in the Martian atmosphere by radio occultation measurements from spacecraft such as the Mars Express Orbiter and the Mars Global Surveyor. These layers are just a few km wide, and tend to occur around 90 km. It has been proposed that the layers consist of metallic ions, for two reasons: they occur in the aerobraking region of the planet where meteoroids ablate; and they resemble sporadic E layers in the terrestrial atmosphere which are known to be composed principally of Fe+ and Mg+ ions. This paper addresses the problem of how metallic ions can persist in a CO2-rich atmosphere, where the ions should be neutralized rapidly by formation of metal-CO2 cluster ions followed by dissociative electron recombination. Laboratory studies using the pulsed laser photolysis/laser induced fluorescence and flow tube/mass spectrometer techniques were used to measure the following rate coefficients: k (Mg+ + CO2 (+ CO2) --> Mg+ x CO2, 190-403 K) = (5.3 +/- 0.7) x 10(-29) (T/300 K)(-1.86 +/- 0.03) cm6 molecule --> 2 s(-1); k(Mg+ x CO2 + O2 --> MgO2(+) + CO2, 297 K) = (2.2 +/- 0.8) x 10(-11) cm3 molecule(-1) s(-1); k(MgO2(+) + O --> MgO(+) + O2, 297 K) = (6.5 +/- 1.8) x 10(-10) cm3 molecule(-1) s(-1); and k(MgO(+) + O --> Mg(+) + O2, 297 K) = (5.9 +/- 2.4) x 10(-10) cm3 molecule(-1) s(-1). A model of magnesium and iron chemistry in the Martian atmosphere was then constructed, which includes meteoric differential ablation rates calculated with the Leeds CABMOD model, photo-ionization, and gas-phase ion-molecule and neutral chemistry. The model shows that nearly all the metallic ions between 70 and 110 km should be Mg+, because the reactions of MgO2+ and MgO+ with atomic O are fast enough to prevent these molecular ions undergoing dissociative electron recombination (unlike the analogous Fe species). There are enough Mg+ ions to form sporadic layers of the observed plasma density, and the layers can have a lifetime against

  11. Extraction of Oxygen from the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    England, C.

    2004-01-01

    A mechanical process was designed for direct extraction of molecular oxygen from the martian atmosphere based on liquefaction of the majority component, CO2, followed by separation of the lower-boiling components. The atmospheric gases are compressed from about 0.007 bar to 13 bar and then cooled to liquefy most of the CO2. The uncondensed gases are further compressed to 30 bar or more, and then cooled again to recover water as ice and to remove much of the remaining CO2. The final gaseous products consisting mostly of nitrogen, oxygen, and carbon monoxide are liquefied and purified by cryogenic distillation. The liquefied CO2 is expanded back to the low-pressure atmosphere with the addition of heat to recover a majority of the compression energy and to produce the needed mechanical work. Energy for the process is needed primarily as heat to drive the CO2-based expansion power system. When properly configured, the extraction process can be a net producer of electricity. The conceptual design, termed 'MARRS' for Mars Atmosphere Resource Recovery System, was based on the NASA/JSC Mars Reference Mission (MRM) requirement for oxygen. This mission requires both liquid oxygen for propellant, and gaseous oxygen as a component of air for the mission crew. With single redundancy both for propellant and crew air, the oxygen requirement for the MRM is estimated at 5.8 kg/hr. The process thermal power needed is about 120 kW, which can be provided at 300-500 C. A lower-cost nuclear reactor made largely of stainless steel could serve as the heat source. The chief development needed for MARRS is an efficient atmospheric compression technology, all other steps being derived from conventional chemical engineering separations. The conceptual design describes an exceptionally low-mass compression system that can be made from ultra-lightweight and deployable structures. This system adapts to the rapidly changing martian environment to supply the atmospheric resource to MARRS at

  12. Absolute ages from crater statistics: Using radiometric ages of Martian samples for determining the Martian cratering chronology

    NASA Technical Reports Server (NTRS)

    Neukum, G.

    1988-01-01

    In the absence of dates derived from rock samples, impact crater frequencies are commonly used to date Martian surface units. All models for absolute dating rely on the lunar cratering chronology and on the validity of its extrapolation to Martian conditions. Starting from somewhat different lunar chronologies, rather different Martian cratering chronologies are found in the literature. Currently favored models are compared. The differences at old ages are significant, the differences at younger ages are considerable and give absolute ages for the same crater frequencies as different as a factor of 3. The total uncertainty could be much higher, though, since the ratio of lunar to Martian cratering rate which is of basic importance in the models is believed to be known no better than within a factor of 2. Thus, it is of crucial importance for understanding the the evolution of Mars and determining the sequence of events to establish an unambiguous Martian cratering chronology from crater statistics in combination with clean radiometric ages of returned Martian samples. For the dating goal, rocks should be as pristine as possible from a geologically simple area with a one-stage emplacement history of the local formation. A minimum of at least one highland site for old ages, two intermediate-aged sites, and one very young site is needed.

  13. Originof magnetite in martian meteorite ALH84001

    NASA Astrophysics Data System (ADS)

    Scott, E.; Fuller, M.

    2003-04-01

    The magnetization of ALH84001 is predominantly carried by single domain magnetite, which is found in association with carbonate. The magnetite is found in topotactic relationship with the carbonate in regions of iron rich carbonate, whereas in magnesium richer areas periclase is found. The magnetite formed from the carbonate by thermal decomposition of siderite at elevated temperature in a major impact event at about 4.0 Gyr. Chromite is also present in large amounts, but it is predominantly paramagnetic at room temperature with a Neel point close to 100^oK. Carbonate with associated magnetite is also found in the martian meteorite Nakhla. Experiments and theory show that siderite is a major product of percolation and evaporation of brines generated under pressures of more than 0.1bar of carbon dioxide. This is the preferred explanation for the carbonate in nakhla, as well as in ALH84001. Thermal decomposition of siderite may result from deep burial, magmatic heat sources, or as in the case of ALH84001, impact heating.

  14. Martian paleolakes and waterways: Exobiological implications

    USGS Publications Warehouse

    Scott, D.H.; Rice, J. W.; Dohm, J.M.

    1991-01-01

    The problems of how warm and wet Mars once was and when climate transitions may have occurred are not well understood. Mars may have had an early environment similar to Earth's that was conductive to the ermergence of life. In addition, increasing geologic evidence indicates that water, upon which terrestrial life depends, has been present on Mars throughout its history. This evidence suggests that life could have developed not only on early Mars but also over longer periods of time in longer lasting, more clement local environments. Indications of past or present life most likely would be found in areas where liquid water existed in sufficient quantities to provide for the needs of biological systems. We suggest that paleolakes may have provided such environments. Unlike the case on Earth, this record of the origin and evolution of life has probably not been erased by extensive deformation of the Martian surface. Our work has identified eleven prospective areas where large lacustrine basins may once have existed. These areas are important for future biological, geological, and climatological investigations. ?? 1991 Kluwer Academic Publishers.

  15. Coaxial Cables for Martian Extreme Temperature Environments

    NASA Technical Reports Server (NTRS)

    Ramesham, Rajeshuni; Harvey, Wayne L.; Valas, Sam; Tsai, Michael C.

    2011-01-01

    Work was conducted to validate the use of the rover external flexible coaxial cabling for space under the extreme environments to be encountered during the Mars Science Laboratory (MSL) mission. The antennas must survive all ground operations plus the nominal 670-Martian-day mission that includes summer and winter seasons of the Mars environment. Successful development of processes established coaxial cable hardware fatigue limits, which were well beyond the expected in-flight exposures. In keeping with traditional qualification philosophy, this was accomplished by subjecting flight-representative coaxial cables to temperature cycling of the same depth as expected in-flight, but for three times the expected number of in-flight thermal cycles. Insertion loss and return loss tests were performed on the coaxial cables during the thermal chamber breaks. A vector network analyzer was calibrated and operated over the operational frequency range 7.145 to 8.450 GHz. Even though some of the exposed cables function only at UHF frequencies (approximately 400 MHz), the testing was more sensitive, and extending the test range down to 400 MHz would have cost frequency resolution. The Gore flexible coaxial cables, which were the subject of these tests, proved to be robust and displayed no sign of degradation due to the 3X exposure to the punishing Mars surface operations cycles.

  16. Volcanoes and volcanic provinces - Martian western hemisphere

    NASA Technical Reports Server (NTRS)

    Scott, D. H.

    1982-01-01

    The recognition of some Martian landforms as volcanoes is based on their morphology and geologic setting. Other structures, however, may exhibit classic identifying features to a varying or a less degree; these may be only considered provisionally as having a volcanic origin. Regional geologic mapping of the western hemisphere of Mars from Viking images has revealed many more probable volcanoes and volcanotectonic features than were recognized on Mariner 9 pictures. These abundant volcanoes have been assigned to several distinct provinces on the basis of their areal distribution. Although the Olympus-Tharsis region remains as the principle center of volcanism on Mars, four other important provinces are now also recognized: the lowland plains, Tempe Terra plateau, southern highlands (in the Phaethontis and Thaumasia quadrangles), and a probable ignimbrite province, situated along the highland-lowland boundary in Amazonis Planitia. Volcanoes in any one province vary in morphlogy, size, and age, but volcanoes in each province tend to have common characteristics that distinguish that particular group.

  17. High-Capacity Communications from Martian Distances

    NASA Technical Reports Server (NTRS)

    Williams, W. Dan; Collins, Michael; Hodges, Richard; Orr, Richard S.; Sands, O. Scott; Schuchman, Leonard; Vyas, Hemali

    2007-01-01

    High capacity communications from Martian distances, required for the envisioned human exploration and desirable for data-intensive science missions, is challenging. NASA s Deep Space Network currently requires large antennas to close RF telemetry links operating at kilobit-per-second data rates. To accommodate higher rate communications, NASA is considering means to achieve greater effective aperture at its ground stations. This report, focusing on the return link from Mars to Earth, demonstrates that without excessive research and development expenditure, operational Mars-to-Earth RF communications systems can achieve data rates up to 1 Gbps by 2020 using technology that today is at technology readiness level (TRL) 4-5. Advanced technology to achieve the needed increase in spacecraft power and transmit aperture is feasible at an only moderate increase in spacecraft mass and technology risk. In addition, both power-efficient, near-capacity coding and modulation and greater aperture from the DSN array will be required. In accord with these results and conclusions, investment in the following technologies is recommended:(1) lightweight (1 kg/sq m density) spacecraft antenna systems; (2) a Ka-band receive ground array consisting of relatively small (10-15 m) antennas; (3) coding and modulation technology that reduces spacecraft power by at least 3 dB; and (4) efficient generation of kilowatt-level spacecraft RF power.

  18. A photochemical model of the martian atmosphere

    NASA Technical Reports Server (NTRS)

    Nair, Hari; Allen, Mark; Anbar, Ariel D.; Yung, Yuk L; Clancy, R. Todd

    1994-01-01

    The factors governing the amounts of CO, O2, and O3 in the martian atmposphere are investigated using a minimally constrained, one-dimensional photochemical model. We find that the incorporation of temperature-dependent CO2 absorption cross sections leads to an enhancement in the water photolysis rate, increasing the abundance of OH radicals to the point where the model CO abundance is smaller that observed. Good agreement between models and observations of CO, O2, O3, and the escape flux of atomic hydrogen can be achieved, using only gas-phase chemistry, by varying the recommended rate constraints for the reaction CO + OH and OH + HO2 within their specified uncertainties. The oxygen escape flux plays a key role in the oxygen budget on Mars; as inferred from the observed atomic hydrogen escape, it is much larger than recent calculations of the exospheric escape rate for oxygen. Weathering of the surface may account for the imbalance. We also consider the possiblity that HO(x) radicals may be catalytically destroyed on dust grains suspended in the atmosphere. Good agreement with the observed CO mixing ratio can be achieved via this mechanism, but the resulting ozone column is much higher than the observed quantity.

  19. Compositional variability of the Martian surface

    NASA Technical Reports Server (NTRS)

    Adams, John B.; Smith, Milton O.

    1991-01-01

    Spectral reflectance data from Viking Landers and Orbiters and from telescopic observations were analyzed with the objective of isolating compositional information about the Martian surface and assessing compositional variability. Two approaches were used to calibrate the data to reflectance to permit direct comparisons with laboratory reference spectra of well characterized materials. In Viking Lander multispectral images (six spectral bands) most of the spectral variation is caused by changes in lighting geometry within individual scenes, from scene to scene, and over time. Lighting variations are both wavelength independent and wavelength dependent. By calibrating lander image radiance values to reflectance using spectral mixture analysis, the possible range of compositions was assessed with reference to a collection of laboratory samples, also resampled to the lander spectral bands. All spectra from the lander images studied plot (in six-space) within a planar triangle having at the apexes the respective spectra of tan basaltic palagonite, gray basalt, and shale. Within this plane all lander spectra fit as mixtures of these three endmembers. Reference spectra that plot outside of the triangle are unable to account for the spectral variation observed in the images.

  20. Martian crater counts on Elysium Mons

    NASA Technical Reports Server (NTRS)

    Mcbride, Kathleen; Barlow, Nadine G.

    1990-01-01

    Without returned samples from the Martian surface, relative age chronologies and stratigraphic relationships provide the best information for determining the ages of geomorphic features and surface regions. Crater-size frequency distributions of six recently mapped geological units of Elysium Mons were measured to establish their relative ages. Most of the craters on Elysium Mons and the adjacent plains units are between 500 and 1000 meters in diameter. However, only craters 1 km in diameter or larger were used because of inadequate spatial resolution of some of the Viking images and to reduce probability of counting secondary craters. The six geologic units include all of the Elysium Mons construct and a portion of the plains units west of the volcano. The surface area of the units studied is approximately 128,000 sq km. Four of the geologic units were used to create crater distribution curves. There are no craters larger than 1 km within the Elysium Mons caldera. Craters that lacked raised rims, were irregularly shaped, or were arranged in a linear pattern were assumed to be endogenic in origin and not counted. A crater frequency distribution analysis is presented.

  1. Inversion of topography in Martian highland terrains

    SciTech Connect

    De Hon, R.A.

    1985-01-01

    Ring furrows are flat-floored trenches, circulate in plan view, forming rings 7 to 50 km in diameter. Typically, ring furrows, which are 0.5 km deep and 2 to 10 km wide, surround a central, flat-topped, circular mesa or plateau. The central plateau is about the same elevation or lower than the plain outside the ring. Ring furrows are unique features of the dissected martian uplands. Related landforms range from ring furrows with fractured central plateaus to circular mesas without encircling moats. Ring furrows are superposed on many types of materials, but they are most common cratered plateau-type materials that are interpreted as volcanic flow material overlying ancient cratered terrain. The ring shape and size suggest that they are related to craters partially buried by lava flows. Ring furrows were formed by preferential removal of exposed rims of partially buried craters. Evidence of overland flow of water is lacking except within the channels. Ground ice decay and sapping followed by fluvial erosion are responsible for removal of the less resistant rim materials. Thus, differential erosion has caused a reversal of topography in which the originally elevated rim is reduced to negative relief.

  2. Orbital monitoring of martian surface changes

    NASA Astrophysics Data System (ADS)

    Geissler, Paul E.; Fenton, Lori K.; Enga, Marie-therese; Mukherjee, Priyanjoli

    2016-11-01

    A history of martian surface changes is documented by a sequence of global mosaics made up of Mars Global Surveyor Mars Orbiter Camera daily color images from 1999 to 2006, together with a single mosaic from the Mars Reconnaissance Orbiter Mars Color Imager in 2009. These observations show that changes in the global albedo patterns of Mars take place by a combination of dust storms and strong winds. Many of the observed surface changes took place along the tracks of seasonally repeating winter dust storms cataloged by Wang and Richardson (2015). These storms tend to sweep dust towards the equator, progressively shifting albedo boundaries and continuing surface changes that began before the arrival of MGS. The largest and most conspicuous changes took place during the global dust storm of 2001 (MY 25), which blanketed Syrtis Major, stripped dust from the Tharsis region, and injected dust into Solis Planum. High wind speeds but low wind stresses are predicted in Syrtis, Tharsis and Solis by the NASA Ames GCM. Frequent changes in these regions show that dust accumulations are quickly removed by stronger winds that are not predicted by the GCM, but may result from smaller-scale influences such as unresolved topography.

  3. Did ice streams carve martian outflow channels?

    USGS Publications Warehouse

    Lucchitta, B.K.; Anderson, D.M.; Shoji, H.

    1981-01-01

    Outflow channels on Mars1 are long sinuous linear depressions that occur mostly in the equatorial area (??30?? lat.). They differ from small valley networks2 by being larger and arising full born from chaotic terrains. Outflow channels resemble terrestrial stream beds, and their origin has generally been attributed to water3-5 in catastrophic floods6,7 or mudflows8. The catastrophic-flood hypothesis is derived primarily from the morphological similarities of martian outflow channels and features created by the catastrophic Spokane flood that formed the Washington scablands. These similarities have been documented extensively3,6,7, but differences of scale remain a major problemmartian channel features are on the average much larger than their proposed terrestrial analogues. We examine here the problem of channel origin from the perspective of erosional characteristics and the resultant landf orms created by former and present-day ice streams and glaciers on Earth. From morphologic comparisons, an ice-stream origin seems equally well suited to explain the occurrences and form of the outflow channels on Mars, and in contrast with the hydraulic hypothesis, ice streams and ice sheets produce terrestrial features of the same scale as those observed on Mars. ?? 1981 Nature Publishing Group.

  4. Plasma acceleration above martian magnetic anomalies.

    PubMed

    Lundin, R; Winningham, D; Barabash, S; Frahm, R; Holmström, M; Sauvaud, J-A; Fedorov, A; Asamura, K; Coates, A J; Soobiah, Y; Hsieh, K C; Grande, M; Koskinen, H; Kallio, E; Kozyra, J; Woch, J; Fraenz, M; Brain, D; Luhmann, J; McKenna-Lawler, S; Orsini, R S; Brandt, P; Wurz, P

    2006-02-17

    Auroras are caused by accelerated charged particles precipitating along magnetic field lines into a planetary atmosphere, the auroral brightness being roughly proportional to the precipitating particle energy flux. The Analyzer of Space Plasma and Energetic Atoms experiment on the Mars Express spacecraft has made a detailed study of acceleration processes on the nightside of Mars. We observed accelerated electrons and ions in the deep nightside high-altitude region of Mars that map geographically to interface/cleft regions associated with martian crustal magnetization regions. By integrating electron and ion acceleration energy down to the upper atmosphere, we saw energy fluxes in the range of 1 to 50 milliwatts per square meter per second. These conditions are similar to those producing bright discrete auroras above Earth. Discrete auroras at Mars are therefore expected to be associated with plasma acceleration in diverging magnetic flux tubes above crustal magnetization regions, the auroras being distributed geographically in a complex pattern by the many multipole magnetic field lines extending into space. PMID:16484488

  5. Martian seismicity through time from surface faulting

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Tanaka, Kenneth L.; Banerdt, W. B.; Tralli, D.

    1991-01-01

    An objective of future Mars missions involves emplacing a seismic network on Mars to determine the internal structure of the planet. An argument based on the relative geologic histories of the terrestrial planets suggests that Mars should be seismically more active than the Moon, but less active than the Earth. The seismicity is estimated which is expected on Mars through time from slip on faults visible on the planets surface. These estimates of martian seismicity must be considered a lower limit as only structures produced by shear faulting visible at the surface today are included (i.e., no provision is made for buried structures or non-shear structures); in addition, the estimate does not include seismic events that do not produce surface displacement (e.g., activity associated with hidden faults, deep lithospheric processes or volcanism) or events produced by tidal triggering or meteorite impacts. Calibration of these estimates suggests that Mars may be many times more seismically active than the Moon.

  6. Cold ion escape from the Martian ionosphere

    NASA Astrophysics Data System (ADS)

    Fränz, M.; Dubinin, E.; Andrews, D.; Barabash, S.; Nilsson, H.; Fedorov, A.

    2015-12-01

    We here report on new measurements of the escape flux of oxygen ions from Mars by combining the observations of the ASPERA-3 and MARSIS experiments on board the European Mars Express spacecraft. We show that in previous estimates of the total heavy ion escape flow the contribution of the cold ionospheric outflow with energies below 10 eV has been underestimated. Both case studies and the derived flow pattern indicate that the cold plasma observed by MARSIS and the superthermal plasma observed by ASPERA-3 move with the same bulk speed in most regions of the Martian tail. We determine maps of the tailside heavy ion flux distribution derived from mean ion velocity distributions sampled over 7 years. If we assume that the superthermal bulk speed derived from these long time averages of the ion distribution function represent the total plasma bulk speed we derive the total tailside plasma flux. Assuming cylindrical symmetry we determine the mean total escape rate for the years 2007-2014 at 2.8 ± 0.4 ×1025 atoms / s which is in good agreement with model estimates. A possible mechanism to generate this flux can be the ionospheric pressure gradient between dayside and nightside.

  7. Plasma acceleration in the Martian magnetotail

    NASA Astrophysics Data System (ADS)

    Esteban Hernandez, Rosa; Modolo, Ronan; Leblanc, François; Chaufray, Jean-Yves; Curry, Shannon M.; Steckiewicz, Morgane; Connerney, John E. P.; McFadden, James P.; Jakosky, Bruce M.; Brain, David A.; DiBraccio, Gina A.; Romanelli, Norberto; Halekas, Jasper S.; Mitchell, David L.

    2016-04-01

    Since November 2014, the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been collecting data from Mars's upper atmosphere and induced magnetosphere (Jakosky et al., 2015). Evidences of escaping planetary ions have been reported from earlier missions as Mars-Express (Barabash et al., 2007) and more recently from MAVEN (e.g. Dong et al., 2015, Brain et al., 2015). Our goal is to determine the acceleration mechanism responsible for the energization of planetary ions in the Martian plasma sheet. MAVEN has a full plasma package with a magnetometer and plasma particles instruments, which allow to address the question of plasma particle acceleration. According to Dubinin et al. (2011), the j x B force due to magnetic shear stresses of the draped field lines is expected to play a major role in such energization process. On MAVEN data, we have first identified and characterized current sheet crossings taking place in Mars' magnetotail and then tested the Walén relation to infer the significance of the j x B force in the particle's energization. To characterize the plasma sheet crossing we have worked with MAVEN magnetometer (MAG, Connerney et al., SSR, 2015) and mass spectrometer (STATIC, McFadden et al., SSR, 2015) data, focusing on a particular event. We have performed a minimum variance analysis, on the magnetic field observations which allows to characterize the current sheet. We present results of the Walén test and our conclusions on planetary plasma acceleration in the plasma sheet region.

  8. MOC Views of Martian Solar Eclipses

    NASA Technical Reports Server (NTRS)

    1999-01-01

    [figure removed for brevity, see original site]

    The shadow of the martian moon, Phobos, has been captured in many recent wide angle camera views of the red planet obtained by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). Designed to monitor changes in weather and surface conditions, the wide angle cameras are also proving to be a good way to spot the frequent solar eclipses caused by the passage of Phobos between Mars and the Sun.

    The first figure (above), shows wide angle red (left), blue (middle), and color composite (right) views of the shadow of Phobos (elliptical feature at center of each frame) as it was cast upon western Xanthe Terra on August 26, 1999, at about 2 p.m.local time on Mars. The image covers an area about 250 kilometers (155 miles) across and is illuminated from the left. The meandering Nanedi Valles is visible in the lower right corner of the scene. Note the dark spots on three crater floors--these appear dark in the red camera image (left) but are barely distinguished in the blue image (middle), while the shadow is dark in both images. The spots on the crater floors are probably small fields of dark sand dunes.

    The second figure shows three samples of MOC's global image swaths, each in this case with a shadow of Phobos visible (arrow). The first scene (left) was taken on September 1, 1999, and shows the shadow of Phobos cast upon southern Elysium Planitia. The large crater with dark markings on its floor at the lower right corner is Herschel Basin. The second scene shows the shadow of Phobos cast upon northern Lunae Planum on September 8, 1999. Kasei Valles dominates the upper right and the deep chasms of Valles Marineris dominate the lower third of the September 8 image. The picture on the right shows the shadow of Phobos near the giant volcano, Olympus Mons (upper left), on September 25, 1999. Three other major volcanoes are visible from lower-center (Arsia Mons) and right-center (Pavonis Mons) to upper

  9. The Cyclic Nature of Martian Satellites

    NASA Astrophysics Data System (ADS)

    Hesselbrock, Andrew; Minton, David A.

    2016-10-01

    The inward tidal decay of Phobos will cause the satellite to rapidly disrupt into a ring as it reaches the Rigid Roche Limit at ~ 1.6 Mars radii in less than 70 My. This ring will viscously spread to eventually form a new generation of satellites at the Fluid Roche Limit at ~ 3.2 Mars radii. We have constructed a ring-satellite model to show that this is only the latest in a series of satellite-ring cycles that have occurred repeatedly throughout Martian history, beginning with a ring created by a giant impact. During each cycle, ring material is deposited onto Mars, decreasing the mass of the ring-satellite system, such that each cycle produces progressively less massive satellites. We find that at least ~ 5 ring/satellite cycles are needed to produce a Phobos mass satellite in its current orbit. Furthermore, the decay of each ring system would have deposited a significant volume of ring material onto Mars throughout the early Noachian and into the late Amazonian. Some anomalous sedimentary deposits on Mars may be linked to these periodic episodes of ring deposition.

  10. Amazonis and Utopia Planitiae: Martian Lacustrine basins

    NASA Technical Reports Server (NTRS)

    Scott, David H.; Rice, James W., Jr.; Dohm, James M.; Chapman, Mary G.

    1992-01-01

    Amazonis and Utopia Planitiae are two large (greater than 10(exp 6) sq. km) basins on Mars having morphological features commonly associated with former lakes. The investigation of these areas is an extension of our previous paleolake studies in the Elysium basin. Using Viking images, we are searching for familiar geologic forms commonly associated with standing bodies of water on Earth. Like Elysium, the two basins exhibit terraces and lineations resembling shorelines, etched and infilled floors with channel-like sinuous markings in places, inflow channels along their borders, and other geomorphic indicators believed to be related to the presence of water and ice. In some areas these features are better displayed than in others where they may be very tenuous; their value as indicators can be justified only by their association with related features. Even though these postulated paleolakes are very young in the Martian stratigraphic sequence, their shoreline features are poorly preserved and they are probably much older than large Pleistocene lakes on Earth.

  11. Plasma acceleration above martian magnetic anomalies.

    PubMed

    Lundin, R; Winningham, D; Barabash, S; Frahm, R; Holmström, M; Sauvaud, J-A; Fedorov, A; Asamura, K; Coates, A J; Soobiah, Y; Hsieh, K C; Grande, M; Koskinen, H; Kallio, E; Kozyra, J; Woch, J; Fraenz, M; Brain, D; Luhmann, J; McKenna-Lawler, S; Orsini, R S; Brandt, P; Wurz, P

    2006-02-17

    Auroras are caused by accelerated charged particles precipitating along magnetic field lines into a planetary atmosphere, the auroral brightness being roughly proportional to the precipitating particle energy flux. The Analyzer of Space Plasma and Energetic Atoms experiment on the Mars Express spacecraft has made a detailed study of acceleration processes on the nightside of Mars. We observed accelerated electrons and ions in the deep nightside high-altitude region of Mars that map geographically to interface/cleft regions associated with martian crustal magnetization regions. By integrating electron and ion acceleration energy down to the upper atmosphere, we saw energy fluxes in the range of 1 to 50 milliwatts per square meter per second. These conditions are similar to those producing bright discrete auroras above Earth. Discrete auroras at Mars are therefore expected to be associated with plasma acceleration in diverging magnetic flux tubes above crustal magnetization regions, the auroras being distributed geographically in a complex pattern by the many multipole magnetic field lines extending into space.

  12. Field Studies of Gullies and Pingos on Svalbard - a Martian Analog.

    NASA Astrophysics Data System (ADS)

    Carlsson, E.; Johannsson, H. A. B.; Johnsson, A.; Heldmann, J. L.; McKay, C. P.; Olvmo, M.; Johansson, L.; Fredriksson, S.; Schmidt, H. T.; McDaniel, S.; Reiss, D.; Hiesinger, H.; Hauber, E.; Zanetti, M.

    2008-09-01

    Introduction: The gully systems on Mars [1] have been found to superpose young geological surfaces such as dunes and thermal contraction polygons [2]. This in combination with the general absence of superimposed impact craters suggest that the gullies are relatively recent geological formations [3]. The observed gullies display a wide set of morphologies ranging from features seemingly formed by fluvial erosion to others pointing to dry landslide processes. A recent discovery [4] suggests that this is an ongoing process, which appears to occur even today. Several formation mechanisms have been proposed for the Martian gullies, such as liquid carbon dioxide reservoirs [5], shallow liquid water aquifer [6], melting ground ice [7], dry landslide [8], snow melt [9] and deep liquid water aquifer [10]. However, none of these models can alone explain all the gullies discovered on Mars. So far Martian gullies have been studied only from orbit via remote sensing data. Hydrostatic pingos are perennial ice-cored mounds that may reach an elongated or circular radius of approximately 150 m. They are found in periglacial environments where they are formed by freezing processes in the continuous permafrost. The pingos go through different evolutionary stages as they mature, where the final stage leaves an annular rim left by the collapse of the summit. Images from the High Resolution Imaging Science Experiment (HiRISE) show small fractured mounds in the Martian mid-latitudes [11]. Even though some differences are observed, the best terrestrial analogues for the observed mound morphology are pingos [11]. Gullies and pingos found in Arctic climates on Earth could be an analog for the Martian ones. A comparative analysis might help to understand the formation mechanisms of the Martian pingos and gullies and their possible eroding agent. Svalbard as a Martian Analog: Svalbard is situated at 74°-81°N and 10°-35°E, in the discontinuous zone of permafrost, and is a fairly good

  13. A Pb isotopic resolution to the Martian meteorite age paradox

    NASA Astrophysics Data System (ADS)

    Bellucci, J. J.; Nemchin, A. A.; Whitehouse, M. J.; Snape, J. F.; Kielman, R. B.; Bland, P. A.; Benedix, G. K.

    2016-01-01

    Determining the chronology and quantifying various geochemical reservoirs on planetary bodies is fundamental to understanding planetary accretion, differentiation, and global mass transfer. The Pb isotope compositions of individual minerals in the Martian meteorite Chassigny have been measured by Secondary Ion Mass Spectrometry (SIMS). These measurements indicate that Chassigny has mixed with a Martian reservoir that evolved with a long-term 238U/204Pb (μ) value ˜ two times higher than those inferred from studies of all other Martian meteorites except 4.428 Ga clasts in NWA7533. Any significant mixing between this and an unradiogenic reservoir produces ambiguous trends in Pb isotope variation diagrams. The trend defined by our new Chassigny data can be used to calculate a crystallization age for Chassigny of 4.526 ± 0.027 Ga (2σ) that is clearly in error as it conflicts with all other isotope systems, which yield a widely accepted age of 1.39 Ga. Similar, trends have also been observed in the Shergottites and have been used to calculate a >4 Ga age or, alternatively, attributed to terrestrial contamination. Our new Chassigny data, however, argue that the radiogenic component is Martian, mixing occurred on the surface of Mars, and is therefore likely present in virtually every Martian meteorite. The presence of this radiogenic reservoir on Mars resolves the paradox between Pb isotope data and all other radiogenic isotope systems in Martian meteorites. Importantly, Chassigny and the Shergottites are likely derived from the northern hemisphere of Mars, while NWA 7533 originated from the Southern hemisphere, implying that the U-rich reservoir, which most likely represents some form of crust, must be widespread. The significant age difference between SNC meteorites and NWA 7533 is also consistent with an absence of tectonic recycling throughout Martian history.

  14. Ancient Crustal Diversity Preserved within Martian Meteorite NWA 7034

    NASA Astrophysics Data System (ADS)

    Santos, A. R.; Agee, C. B.; McCubbin, F. M.; Shearer, C. K.; Burger, P. V.

    2014-12-01

    The martian meteorite Northwest Africa (NWA) 7034 is a breccia containing a variety of igneous clasts and igneous derived mineral fragments suspended in a matrix of fine grained material. Igneous clasts were examined using electron probe microanalysis (major and minor element compositions), BSE images (modal mineralogy), and secondary ion mass spectrometry (REEs). The clasts contain minerals of similar composition to martian meteorites and surface rocks, although mineral abundances differ between these clasts and other martian rocks. The clasts vary in rock type and include basalt, andesite, trachyandesite, and an exotic phosphate and FeTi-oxide rich lithology that is more Fe-rich than Wishstone-class rocks analyzed by MER. Many of the basaltic clast compositions match those of Gusev Crater rocks, as well as the average composition of the martian crust determined from orbital data, providing a strong link between this meteorite and the martian crust. Furthermore, studies have shown the majority of igneous materials in this meteorite to be ~4.4 Ga (Yin et al., 2014; Nyquist et al., 2013, Tartèse et al., 2014); this suggests these clasts represent some of the earliest formed martian crust. The range in rock types contained within this meteorite suggest early Mars was capable of producing crust that was diverse in composition, chemically enriched, and oxidized (ΔFMQ +0.7 to +4), at least in local regions. The reason for the difference in chemistry between these ancient crustal rocks and the younger SNC meteorites remains to be determined, but the lithologic diversity recorded by NWA 7034 provides evidence for a petrologically diverse martian surface both spatially and temporally.

  15. The Pb isotopic evolution of the Martian mantle constrained by initial Pb in Martian meteorites

    NASA Astrophysics Data System (ADS)

    Bellucci, J. J.; Nemchin, A. A.; Whitehouse, M. J.; Snape, J. F.; Bland, P.; Benedix, G. K.

    2015-12-01

    The Pb isotopic compositions of maskelynite and pyroxene grains were measured in ALH84001 and three enriched shergottites (Zagami, Roberts Massif 04262, and Larkman Nunatuk 12011) by secondary ion mass spectrometry. A maskelynite-pyroxene isochron for ALH84001 defines a crystallization age of 4089 ± 73 Ma (2σ). The initial Pb isotopic composition of each meteorite was measured in multiple maskelynite grains. ALH84001 has the least radiogenic initial Pb isotopic composition of any Martian meteorite measured to date (i.e., 206Pb/204Pb = 10.07 ± 0.17, 2σ). Assuming an age of reservoir formation for ALH84001 and the enriched shergottites of 4513 Ma, a two-stage Pb isotopic model has been constructed. This model links ALH84001 and the enriched shergottites by their similar μ value (238U/204Pb) of 4.1-4.6 from 4.51 Ga to 4.1 Ga and 0.17 Ga, respectively. The model employed here is dependent on a chondritic μ value (~1.2) from 4567 to 4513 Ma, which implies that core segregation had little to no effect on the μ value(s) of the Martian mantle. The proposed Pb isotopic model here can be used to calculate ages that are in agreement with Rb-Sr, Lu-Hf, and Sm-Nd ages previously determined in the meteorites and confirm the young (~170 Ma) ages of the enriched shergottites and ancient, >4 Ga, age of ALH84001.

  16. Analysis and survival of amino acids in Martian regolith analogs

    NASA Astrophysics Data System (ADS)

    Garry, James R. C.; Loes Ten Kate, Inge; Martins, Zita; Nørnberg, Per; Ehrenfreund, Pascale

    2006-03-01

    We have investigated the native amino acid composition of two analogs of Martian soil, JSC Mars-1 and Salten Skov. A Mars simulation chamber has been built and used to expose samples of these analogs to temperature and lighting conditions similar to those found at low latitudes on the Martian surface. The effects of the simulated conditions have been examined using high-performance liquid chromatography (HPLC). Exposure to energetic ultraviolet (UV) light in vacuum appears to cause a modest increase in the concentration of certain amino acids within the materials, which is interpreted as resulting from the degradation of microorganisms. The influence of low temperatures shows that the accretion of condensed water on the soils leads to the destruction of amino acids, supporting the idea that reactive chemical processes involving H2O are at work within the Martian soil. We discuss the influence of UV radiation, low temperatures, and gaseous CO2 on the intrinsic amino acid composition of Martian soil analogs and describe, with the help of a simple model, how these studies fit within the framework of life detection on Mars and the practical tasks of choosing and using Martian regolith analogs in planetary research.

  17. Liquid Water in the Extremely Shallow Martian Subsurface

    NASA Technical Reports Server (NTRS)

    Pavlov, A.; Shivak, J. N.

    2012-01-01

    Availability of liquid water is one of the major constraints for the potential Martian biosphere. Although liquid water is unstable on the surface of Mars due to low atmospheric pressures, it has been suggested that liquid films of water could be present in the Martian soil. Here we explored a possibility of the liquid water formation in the extremely shallow (1-3 cm) subsurface layer under low atmospheric pressures (0.1-10 mbar) and low ("Martian") surface temperatures (approx.-50 C-0 C). We used a new Goddard Martian simulation chamber to demonstrate that even in the clean frozen soil with temperatures as low as -25C the amount of mobile water can reach several percents. We also showed that during brief periods of simulated daylight warming the shallow subsurface ice sublimates, the water vapor diffuses through porous surface layer of soil temporarily producing supersaturated conditions in the soil, which leads to the formation of additional liquid water. Our results suggest that despite cold temperatures and low atmospheric pressures, Martian soil just several cm below the surface can be habitable.

  18. Martian mud volcanism: Terrestrial analogs and implications for formational scenarios

    USGS Publications Warehouse

    Skinner, J.A.; Mazzini, A.

    2009-01-01

    The geology of Mars and the stratigraphic characteristics of its uppermost crust (mega-regolith) suggest that some of the pervasively-occurring pitted cones, mounds, and flows may have formed through processes akin to terrestrial mud volcanism. A comparison of terrestrial mud volcanism suggests that equivalent Martian processes likely required discrete sedimentary depocenters, volatile-enriched strata, buried rheological instabilities, and a mechanism of destabilization to initiate subsurface flow. We outline five formational scenarios whereby Martian mud volcanism might have occurred: (A) rapid deposition of sediments, (B) volcano-induced destabilization, (C) tectonic shortening, (D) long-term, load-induced subsidence, and (E) seismic shaking. We describe locations within and around the Martian northern plains that broadly fit the geological context of these scenarios and which contain mud volcano-like landforms. We compare terrestrial and Martian satellite images and examine the geological settings of mud volcano provinces on Earth in order to describe potential target areas for piercement structures on Mars. Our comparisons help to evaluate not only the role of water as a functional component of geological processes on Mars but also how Martian mud volcanoes could provide samples of otherwise inaccessible strata, some of which could contain astrobiological evidence.

  19. Investigating the Martian Ionospheric Conductivity Using MAVEN Key Parameter Data

    NASA Astrophysics Data System (ADS)

    Aleryani, O.; Raftery, C. L.; Fillingim, M. O.; Fogle, A. L.; Dunn, P.; McFadden, J. P.; Connerney, J. E. P.; Mahaffy, P. R.; Ergun, R. E.; Andersson, L.

    2015-12-01

    Since the Viking orbiters and landers in 1976, the Martian atmospheric composition has scarcely been investigated. New data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, launched in 2013, allows for a thorough study of the electrically conductive nature of the Martian ionosphere. Determinations of the electrical conductivity will be made using in-situ atmospheric and ionospheric measurements, rather than scientific models for the first time. The objective of this project is to calculate the conductivity of the Martian atmosphere, whenever possible, throughout the trajectory of the MAVEN spacecraft. MAVEN instrumentation used includes the Neutral Gas and Ion Mass Spectrometer (NGIMS) for neutral species density, the Suprathermal and Thermal Ion Compositions (STATIC) for ion composition, temperature and density, the Magnetometer (MAG) for the magnetic field strength and the Langmuir Probe and Waves (LPW) for electron temperature and density. MAVEN key parameter data are used for these calculations. We compare our results with previous, model-based estimates of the conductivity. These results will allow us to quantify the flow of atmospheric electric currents which can be analyzed further for a deeper understanding of the Martian ionospheric electrodynamics, bringing us closer to understanding the mystery of the loss of the Martian atmosphere.

  20. LU-HF Age of Martian Meteorite Larkman Nunatek 06319

    NASA Technical Reports Server (NTRS)

    Shafer, J. T.; Brandon, A. D.; Lapen, T. J.; Righter, M.; Beard, B.; Peslier, A. H.

    2009-01-01

    Lu-Hf isotopic data were collected on mineral separates and bulk rock powders of LAR 06319, yielding an age of 197+/- 29 Ma. Sm-Nd isotopic data and in-situ LA-ICP-MS data from a thin section of LAR 06319 are currently being collected and will be presented at the 2009 LPSC. These new data for LAR 06319 extend the existing data set for the enriched shergottite group. Martian meteorites represent the only opportunity for ground truth investigation of the geochemistry of Mars [1]. At present, approximately 80 meteorites have been classified as Martian based on young ages and distinctive isotopic signatures [2]. LAR 06319 is a newly discovered (as part of the 2006 ANSMET field season) martian meteorite that represents an important opportunity to further our understanding of the geochemical and petrological constraints on the origin of Martian magmas. Martian meteorites are traditionally categorized into the shergottite, nakhlite, and chassignite groups. The shergottites are further classified into three distinct isotopic groups designated depleted, intermediate, and enriched [3,4] based on the isotope systematics and compositions of their source(s).

  1. Water in Pyroxene and Olivine from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Peslier, A. H.

    2012-01-01

    Water in the interior of terrestrial planets can be dissolved in fluids or melts and hydrous phases, but can also be locked as protons attached to structural oxygen in lattice defects in nominally anhydrous minerals (NAM) like olivine, pyroxene, or feldspar [1-3]. Although these minerals contain only tens to hundreds of ppm H2O, this water can amount to at least one ocean in mass when added at planetary scales because of the modal dominance of NAM in the mantle and crust [4]. Moreover these trace amounts of water can have drastic effects on melting temperature, rheology, electrical and heat conductivity, and seismic wave attenuation [5]. There is presently a debate on how much water is present in the martian mantle. Secondary ionization mass spectrometry (SIMS) studies of NAM [6], amphiboles and glass in melt inclusions [7-10], and apatites [11, 12] from Martian meteorites report finding as much water as in the same phases from Earth's igneous rocks. Most martian hydrous minerals, however, generally have the relevant sites filled with Cl and F instead of H [13, 14], and experiments using Cl [15] in parent melts can reproduce Martian basalt compositions as well as those with water [16]. We are in the process of analyzing Martian meteorite minerals by Fourier transform infrared spectrometry (FTIR) in order to constrain the role of water in this planet s formation and magmatic evolution

  2. The Martian Radiation Environment from Orbit and on the Surface

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Howe, S. D.

    1999-01-01

    A good knowledge of the Martian radiation environment and its interactions with Mars is needed for many reasons. It is needed to help unfold the results of the Mars-2001 orbiter's gamma-ray spectrometer (GRS) and neutron spectrometers (NS) to determine elemental abundances on the Martian surface. It is needed to interpret the measurements of the Martian Radiation Environment Experiments (MARIE) on both the Mars 2001 orbiter and lander. It is needed to calculate production rates of cosmogenic nuclides that will be measured in samples returned from Mars. It is needed to determine the doses that astronauts would receive in Martian orbit and especially on the surface of Mars. We discuss the two types of energetic particles in the vicinity of Mars and the nature of their interactions. Solar energetic particles (SEPs) occur very rarely but can have high fluxes that are dangerous in space. However, their energies are low enough that few solar energetic particles reach the surface of Mars. Their interactions can be fairly easily modeled because SEPs create few secondary particles. Galactic cosmic rays (GCRs) have high energies and are the dominant source of energetic particles on the Martian surface, mainly secondary neutrons. Modeling their interactions is complicated because of the range of nuclei in the GCR and their high energies. Work at Los Alamos on GCR interactions will be presented.

  3. Genetic implications of the shapes of martian and lunar craters

    USGS Publications Warehouse

    Pike, R.J.

    1971-01-01

    Craters on Mars and the Moon are alike in that larger craters differ in shape from smaller ones, and older craters differ in shape from younger ones. Smoothed depth-diameter curves for 41 large martian craters photographed by Mariner IV inflect at a crater diameter of 10-20km in a manner similar to curves for lunar craters. Below 10-20km, both depth-diameter curves are linear with a slope of roughly 1.0; above this threshold range, the curves assume a much lower slope. Diminution of lunar crater depth-diameter ratios with age indicates that the shapes of lunar and, by inference, martian craters have changed systematically since formation. Martian craters sampled here are shallower than most pre-Imbrian lunar craters. By analogy with the Moon, martian craters seem both to vary in initial shape according to the energy of the impact that formed them and to have been modified subsequently by endogenic and surface processes. A proposed model for the geologic development of large martian and lunar craters outlines a time- dependent sequence of events. Craters which have undergone rapid isostatic adjustment on the Moon have distinctive morphologies and occur preferentially along mare basin-upland margins. ?? 1972.

  4. Martian Atmospheric and Ionospheric plasma Escape

    NASA Astrophysics Data System (ADS)

    Lundin, Rickard

    2016-04-01

    Solar forcing is responsible for the heating, ionization, photochemistry, and erosion processes in the upper atmosphere throughout the lifetime of the terrestrial planets. Of the four terrestrial planets, the Earth is the only one with a fully developed biosphere, while our kin Venus and Mars have evolved into arid inhabitable planets. As for Mars, there are ample evidences for an early Noachian, water rich period on Mars. The question is, what made Mars evolve so differently compared to the Earth? Various hydrosphere and atmospheric evolution scenarios for Mars have been forwarded based on surface morphology, chemical composition, simulations, semi-empiric (in-situ data) models, and the long-term evolution of the Sun. Progress has been made, but the case is still open regarding the changes that led to the present arid surface and tenuous atmosphere at Mars. This presentation addresses the long-term variability of the Sun, the solar forcing impact on the Martian atmosphere, and its interaction with the space environment - an electromagnetic wave and particle interaction with the upper atmosphere that has implications for its photochemistry, composition, and energization that governs thermal and non-thermal escape. Non-thermal escape implies an electromagnetic upward energization of planetary ions and molecules to velocities above escape velocity, a process governed by a combination of solar EUV radiation (ionization), and energy and momentum transfer by the solar wind. The ion escape issue dates back to the early Soviet and US-missions to Mars, but the first more accurate estimates of escape rates came with the Phobos-2 mission in 1989. Better-quality ion composition measurement results of atmospheric/ionospheric ion escape from Mars, obtained from ESA Mars Express (MEX) instruments, have improved our understanding of the ion escape mechanism. With the NASA MAVEN spacecraft orbiting Mars since Sept. 2014, dual in-situ measurement with plasma instruments are now

  5. A lunar/Martian anchor emplacement system

    NASA Technical Reports Server (NTRS)

    Clinton, Dustin; Holt, Andrew; Jantz, Erik; Kaufman, Teresa; Martin, James; Weber, Reed

    1993-01-01

    On the Moon or Mars, it is necessary to have an anchor, or a stable, fixed point able to support the forces necessary to rescue a stuck vehicle, act as a stake for a tent in a Martian gale, act as a fulcrum in the erection of general construction poles, or support tent-like regolith shields. The anchor emplacement system must be highly autonomous. It must supply the energy and stability for anchor deployment. The goal of the anchor emplacement system project is to design and build a prototype anchor and to design a conceptual anchor emplacement system. Various anchors were tested in a 1.3 cubic meter test bed containing decomposed granite. A simulated lunar soil was created by adjusting the moisture and compaction characteristics of the soil. We conducted tests on emplacement torque, amount of force the anchor could withstand before failure, anchor pull out force at various angles, and soil disturbances caused by placing the anchor. A single helix auger anchor performed best in this test bed based on energy to emplace, and the ultimate holding capacity. The anchor was optimized for ultimate holding capacity, minimum emplacement torque, and minimum soil disturbance in sandy soils yielding the following dimensions: helix diameter (4.45 cm), pitch (1.27 cm), blade thickness (0.15 cm), total length (35.56 cm), shaft diameter (0.78 cm), and a weight of 212.62 g. The experimental results showed that smaller diameter, single-helix augers held more force than larger diameter augers for a given depth. The emplacement system consists of a flywheel and a motor for power, sealed in a protective box supported by four legs. The flywheel system was chosen over a gear system based on its increased reliability in the lunar environment.

  6. Hydrated Minerals in the Martian Southern Highlands

    NASA Astrophysics Data System (ADS)

    Wray, James J.; Seelos, F. P.; Murchie, S. L.; Squyres, S. W.

    2008-09-01

    Hydrated minerals including sulfates, phyllosilicates, and hydrated silica have been observed on the surface of Mars by the orbital near-infrared spectrometers OMEGA and CRISM [1,2]. Global maps from OMEGA [3,4] show that km-scale and larger exposures of these minerals are scattered widely throughout the planet's low and mid latitudes, but are relatively rare. Yet CRISM has found hundreds to thousands of Fe/Mg-phyllosilicate exposures in the highlands of Terra Tyrrhena alone [2], suggesting that smaller exposures may be much more common. To search for such exposures, we have surveyed the browse products from all PDS-released CRISM targeted observations (as of July 2008) across a large fraction of the Southern highlands, including the Noachis, Cimmeria, and Sirenum regions. Sulfates are observed in Noachian-aged terrains in each of these regions, including as far South as -63º latitude, suggesting that sulfate formation may have occurred locally or regionally throughout a large fraction of Martian history. Some of our strongest phyllosilicate detections occur adjacent to inferred chloride-bearing deposits [5] in Terra Sirenum. Also in Sirenum, the D 100 km Columbus crater contains light-toned, hydrated sulfate-bearing layers overlying materials that contain both a kaolin group clay and Fe/Mg-smectite clay, in different locations. However, phyllosilicates do not appear predominantly associated with impact craters in the regions surveyed, in contrast with Terra Tyrrhena [2]. We are currently searching for additional hydrated mineral exposures using CRISM multispectral data, providing further detail on their global distribution and identifying local areas of interest for future focused studies. [1] Bibring, J.-P. et al. (2005) Science 307, 1576-1581. [2] Mustard, J. F. et al. (2008) Nature 454, 305-309. [3] Bibring, J.-P. et al. (2006) Science 312, 400-404. [4] Poulet, F. et al. (2007) Mars 7, Abs. #3170. [5] Osterloo M. M. et al. (2008) Science 319, 1651-1654.

  7. Moessbauer Spectroscopy of Martian and Sverrefjell Carbonates

    NASA Technical Reports Server (NTRS)

    Agresti, David G.; Morris, Richard V.

    2011-01-01

    Mars, in its putative "warmer, wetter: early history, could have had a CO2 atmosphere much denser than its current value of <10 mbar. The question of where all this early CO2 has gone has long been debated. Now, several instruments on Mars Exploration Rover (MER) Spirit, including its Moessbauer spectrometer MIMOS II, have identified Mg-Fe carbonate in rock outcrops at Comanche Spur in the Columbia Hills of Gusev Crater. With this finding, carbonate cements in volcanic breccia collected on Sverrefjell Volcano on Spitzbergen Island in the Svalbard Archipelago (Norway) during the AMASE project are mineralogical and possible process analogues of the newly discovered martian carbonate. We report further analyses of Mossbauer spectra from Comanche Spur and discuss their relationship to Mossbauer data acquired on Sverrefjell carbonates. The spectra were velocity calibrated with MERView and fit using MERFit. Instead of the "average temperature" Comanche spectrum (data from all temperature windows summed), we refit the Comanche data for QS within each temperature window, modeling as doublets for Fe2+(carbonate), Fe2+(olivine), and Fe3+(npOx). The temperature dependences of QS for the Comanche carbonate and for a low-Ca carbonate from Chocolate Pots in Yellowstone National Park (YNP) are shown; they are the same within error. For Comanche carbonate summed over 210-270 K, (CS, QS) = (1.23, 1.95) mm/s. The value of QS for Sverrefjell carbonate at 295 K, (CS, QS) = (1.25, 1.87) mm/s, is also plotted, and the plot shows that the QS for the Sverrefjell carbonate agrees within error with the Comanche data extrapolated to 295 K. This agreement is additional evidence that the Sverrefjell carbonates are Mossbauer analogues for the Comanche carbonates, and that both carbonates might have precipitated from solutions that became carbonate rich by passing through buried carbonate deposits.

  8. Martian Arctic Dust Devil, Phoenix Sol 104

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Surface Stereo Imager on NASA's Phoenix Mars Lander caught this dust devil in action west-southwest of the lander at 11:16 a.m. local Mars time on Sol 104, or the 104th Martian day of the mission, Sept. 9, 2008.

    Dust devils have not been detected in any Phoenix images from earlier in the mission, but at least six were observed in a dozen images taken on Sol 104.

    Dust devils are whirlwinds that often occur when the Sun heats the surface of Mars, or some areas on Earth. The warmed surface heats the layer of atmosphere closest to it, and the warm air rises in a whirling motion, stirring dust up from the surface like a miniature tornado.

    The dust devil visible in the center of this image just below the horizon is estimated to be about 400 meters (about 1,300 feet) from Phoenix, and 4 meters (13 feet) in diameter. It is much smaller than dust devils that have been observed by NASA's Mars Exploration Rover Spirit much closer to the equator. It is closer in size to dust devils seen from orbit in the Phoenix landing region, though still smaller than those.

    The image has been enhanced to make the dust devil easier to see.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  9. Martian Sedimentary Basins and Central Mound Formation

    NASA Astrophysics Data System (ADS)

    Bennett, K. A.; Bell, J. F., III

    2014-12-01

    Central mounds on Mars are observed as sedimentary deposits within crater interiors, but the specific processes responsible for their formation and subsequent modification are still debated. The deposits are hypothesized to have been created by either subaerial or subaqueous processes through one of two general formation mechanisms. The prevailing hypothesis suggests that after their craters were formed, sediment filled the entire crater and was later eroded into the morphologies we observe today. Alternatively, the sediment could have been deposited as the features we observe today without any significant erosion contributing to their mound shape. We conducted a survey of central mounds that occur within craters larger than 25 km in diameter located between ± 60° latitude on Mars. We use mound locations, mound offsets within their host craters, and mound heights to address various mound formation hypotheses. The results of this survey support the hypothesis that mound sediment once filled the entire host crater and was later eroded into the features we observe today. We propose that large Martian impact craters act as simplistic sedimentary basins. These basins "catch" any sediment that is being transported through the region. Any geologic process that involves transport of material (airfall dust, explosive volcanism, impact ejecta, etc.) could have contributed to the growth of this sediment fill, although the dominant process could vary based on location. During this depositional phase, several processes (ice/frost, water, etc.) could have cemented the material; then, at some point, the environment changed from depositional to erosional, leading to the formation of isolated mounds of sediment within these craters. Our study reveals that most mounds are offset from the center of their host crater in the same direction as the regional winds. For example, the mounds in Arabia Terra are offset towards the western portion of their craters. This observation is

  10. A Bootstrap Approach to Martian Manufacturing

    NASA Technical Reports Server (NTRS)

    Dorais, Gregory A.

    2004-01-01

    In-Situ Resource Utilization (ISRU) is an essential element of any affordable strategy for a sustained human presence on Mars. Ideally, Martian habitats would be extremely massive to allow plenty of room to comfortably live and work, as well as to protect the occupants from the environment. Moreover, transportation and power generation systems would also require significant mass if affordable. For our approach to ISRU, we use the industrialization of the U.S. as a metaphor. The 19th century started with small blacksmith shops and ended with massive steel mills primarily accomplished by blacksmiths increasing their production capacity and product size to create larger shops, which produced small mills, which produced the large steel mills that industrialized the country. Most of the mass of a steel mill is comprised of steel in simple shapes, which are produced and repaired with few pieces of equipment also mostly made of steel in basic shapes. Due to this simplicity, we expect that the 19th century manufacturing growth can be repeated on Mars in the 21st century using robots as the primary labor force. We suggest a "bootstrap" approach to manufacturing on Mars that uses a "seed" manufacturing system that uses regolith to create major structural components and spare parts. The regolith would be melted, foamed, and sintered as needed to fabricate parts using casting and solid freeform fabrication techniques. Complex components, such as electronics, would be brought from Earth and integrated as needed. These parts would be assembled to create additional manufacturing systems, which can be both more capable and higher capacity. These subsequent manufacturing systems could refine vast amounts of raw materials to create large components, as well as assemble equipment, habitats, pressure vessels, cranes, pipelines, railways, trains, power generation stations, and other facilities needed to economically maintain a sustained human presence on Mars.

  11. Petrology of Martian meteorite Northwest Africa 998

    NASA Astrophysics Data System (ADS)

    Treiman, Allan H.; Irving, Anthony J.

    2008-05-01

    Nakhlite Northwest Africa (NWA) 998 is an augite-rich cumulate igneous rock with mineral compositions and oxygen isotopic composition consistent with an origin on Mars. This 456-gram, partially fusion-crusted meteorite consists of (by volume) ˜75% augite (core composition Wo39En39Fs22), ˜9% olivine (Fo35), ˜7% plagioclase (Ab61An35) as anhedra among augite and olivine, ˜3.5% low-calcium pyroxenes (pigeonite and orthopyroxene) replacing or forming overgrowths on olivine and augite, ˜1% titanomagnetite, and other phases including potassium feldspar, apatite, pyrrhotite, chalcopyrite, ilmenite, and fine-grained mesostasis material. Minor secondary alteration materials include "iddingsite" associated with olivine (probably Martian), calcite crack fillings, and iron oxide/hydroxide staining (both probably terrestrial). Shock effects are limited to minor cataclasis and twinning in augite. In comparison to other nakhlites, NWA 998 contains more low-calcium pyroxenes and its plagioclase crystals are blockier. The large size of the intercumulus feldspars and the chemical homogeneity of the olivine imply relatively slow cooling and chemical equilibration in the late- and post-igneous history of this specimen, and mineral thermometers give subsolidus temperatures near 730 °C. Oxidation state was near that of the QFM buffer, from about QFM-2 in earliest crystallization to near QFM in late crystallization, and to about QFM + 1.5 in some magmatic inclusions. The replacement or overgrowth of olivine by pigeonite and orthopyroxene (with or without titanomagnetite), and the marginal replacement of augite by pigeonite, are interpreted to result from late-stage reactions with residual melts (consistent with experimental phase equilibrium relationships). Apatite is concentrated in planar zones separating apatite-free domains, which suggests that residual magma (rich in P and REE) was concentrated in planar (fracture?) zones and possibly migrated through them. Loss of late magma

  12. Noachian Martian Volcanics a Water Source

    NASA Technical Reports Server (NTRS)

    Zent, A. P.; Glaze, L. S.; Baloga, S. M.; Fonda, Mark (Technical Monitor)

    2002-01-01

    H2O was supplied to the Noachian atmosphere by eruptions, or in association with large impacts. Most water outgassed into an extremely cold atmosphere, and condensate deposits were inevitable. High heat flow could lead to subglacial melting only if ice thicknesses were greater than 500-1000m, which is extremely unlikely. Subareal melting and flow is contingent upon temperatures periodically exceeding 273 K, and retarding evaporative loss of the flow. In still air, evaporation into a dry atmosphere is in the free convection regime, and a stream with 2 cu m/s discharge, flowing 1 m/s could persist for hundreds of days and cover distances greater than any valley reach. The zero-wind-shear condition is considered implausible however. We investigate the possibility that evaporation rates were suppressed because the atmosphere was regionally charged with H2O as it moved over snow/ice fields. Our initial concern is precipitation from volcanic plumes. A Kilauea-style eruption on the martian surface would cover a 10km circular deposit with 10cm of H2O, if all H2O could be precipitated near the vent. The characteristics of the eruption at the vent, (vent size, temperature, H2O content, etc.) are independent of the environmental conditions. The subsequent behavior of the plume, including precipitation of ash and H2O condensate depends strongly on the environment. Hence, the proximal fate of volcanic H2O is amenable to treatment in a model. A simple bulk thermodynamic model of the rise of an H2O plume through a stably stratified CO2 atmosphere, with only adiabatic cooling, produces runaway plume rise. A more complex treatment includes the effects of latent heat release, wind shear along the plume, divergence of ash and H2O, and will yield more realistic estimates of H2O transport in eruptive plumes. Results of these simulations will be presented.

  13. Compression of Martian atmosphere for production of oxygen

    NASA Technical Reports Server (NTRS)

    Lynch, D. C.; Cutler, A. H.; Nolan, P. E.

    1991-01-01

    The compression of CO2 from the Martian atmosphere for production of O2 via an electrochemical cell is addressed. Design specifications call for an oxygen production rate of 10 kg per day and for compression of 50 times that mass of CO2. Those specifications require a compression rate of over 770 cfm at standard Martian temperature and pressure (SMTP). Much of the CO2 being compressed represents waste, unless it can be recycled. Recycling can reduce the volume of gas that must be compressed to 40 cfm at SMTP. That volume reduction represents significant mass savings in the compressor, heating equipment, filters, and energy source. Successful recycle of the gas requires separation of CO (produced in the electrochemical cell) from CO2, N2, and Ar found in the Martian atmosphere. That aspect was the focus of this work.

  14. The effect of solar energetic particles on the Martian ionosphere

    NASA Astrophysics Data System (ADS)

    Darwish, Omar Hussain Al; Lillis, Robert; Fillingim, Matthew; Lee, Christina

    2016-10-01

    The precipitation of Solar Energetic Particles (SEP) into the Martian atmosphere causes several effects, one of the most important of which is ionization. However, the importance of this process to the global structure and dynamics for the Martian ionosphere is currently not well understood. The MAVEN spacecraft carries instrumentation which allow us to examine this process. The Neutral Gas and Ion Mass Spectrometer (NGIMS) measures the densities of planetary ions in the Mars ionosphere (O+,CO2+ and O2+). The Solar Energetic Particle (SEP) detector measures the fluxes of energetic protons and electrons. In this project, we examine the degree to which the density of ions in the Martian ionosphere is affected by the precipitation of energetic particles, under conditions of different SEP ion and electron fluxes and at various solar zenith angles. We will present statistical as well as case studies.

  15. Iron Redox Systematics of Shergottites and Martian Magmas

    NASA Technical Reports Server (NTRS)

    Righter, Kevin; Danielson, L. R.; Martin, A. M.; Newville, M.; Choi, Y.

    2010-01-01

    Martian meteorites record a range of oxygen fugacities from near the IW buffer to above FMQ buffer [1]. In terrestrial magmas, Fe(3+)/ SigmaFe for this fO2 range are between 0 and 0.25 [2]. Such variation will affect the stability of oxides, pyroxenes, and how the melt equilibrates with volatile species. An understanding of the variation of Fe(3+)/SigmaFe for martian magmas is lacking, and previous work has been on FeO-poor and Al2O3-rich terrestrial basalts. We have initiated a study of the iron redox systematics of martian magmas to better understand FeO and Fe2O3 stability, the stability of magnetite, and the low Ca/high Ca pyroxene [3] ratios observed at the surface.

  16. SNC meteorites and their implications for reservoirs of Martian volatiles

    NASA Technical Reports Server (NTRS)

    Jones, J. H.

    1993-01-01

    The SNC meteorites and the measurements of the Viking landers provide our only direct information about the abundance and isotopic composition of Martian volatiles. Indirect measurements include spectroscopic determinations of the D/H ratio of the Martian atmosphere. A personal view of volatile element reservoirs on Mars is presented, largely as inferred from the meteoritic evidence. This view is that the Martian mantle has had several opportunities for dehydration and is most likely dry, although not completely degassed. Consequently, the water contained in SNC meteorites was most likely incorporated during ascent through the crust. Thus, it is possible that water can be decoupled from other volatile/incompatible elements, making the SNC meteorites suspect as indicators of water inventories on Mars.

  17. Early Martian environments - The antarctic and other terrestrial analogs

    NASA Technical Reports Server (NTRS)

    Wharton, R. A., Jr.; Mckay, C. P.; Mancinelli, R. L.; Simmons, G. M., Jr.

    1989-01-01

    The comparability of the early environments of Mars and earth, and the biological evolution which occurred on early earth, motivates serious consideration of the possibility of an early Martian biota. Environments which could have contained this early Martian life and which may presently contain evidence of this former life include aquatic, ice, soil, and rock habitats. Several analogs of these potential early Martian environments, which can provide useful information in searching for extinct life on Mars, are currently available for study on earth. These terrestrial analogs include the perennially ice-covered lakes and sandstone rocks in the polar deserts of Antarctica, surface of snowfields and glaciers, desert soils, geothermal springs, and deep subsurface environments.

  18. Field Innovations in Support of Martian Polar Expeditions

    NASA Astrophysics Data System (ADS)

    Cockell, C. S.

    The Martian poles present a challenging environment for expedition planners. I review and describe innova- tions in support of human Martian polar expeditions that are a direct extrapolation of terrestrial polar explora- tion equipment. Ball tents provide an environment for de-suiting at the end of daily expedition traverse and can be used to establish temporary field camps and depots for transpolar expeditions or deep-field scientific outposts. Sublimation poles, netting and heating boxes allow for the harvesting of polar ices for water, oxygen and fuel production. Pressurization of ices prior to melting allows liquid water to be collected, thus reducing energy expenditure compared to ice vaporization. Sublimation nets additionally are used for the removal of CO2 frost from expedition equipment. Human mobility can be achieved with sledges and rovers. These innova- tions, when combined, make possible the planning of human scientific and expeditionary EVAs on the Martian polar ice caps.

  19. Mars-relevant phosphate minerals and implications for Martian habitability

    NASA Astrophysics Data System (ADS)

    Adcock, Christopher T.

    This dissertation is comprised of three studies focused on martian phosphate availability, with an introductory chapter introducing and linking the three studies. Chapter two is on the subject of merrillite synthesis. Merrillite is an extraterrestrial Ca-phosphate mineral similar to the mineral whitlockite and is found as a dominant primary phosphate mineral in martian meteorites. The chapter includes methods of whitlockite and merrillite synthesis as well as a detailed characterization of the produced minerals and a mechanism by which charge balance can be maintained when merrillite is synthesized through dehydrogenation of whitlockite. Chapter three presents the results of kinetic and thermodynamic studies on the Mars-relevant minerals chlorapatite and merrillite, as well as the more terrestrially-relevant minerals whitlockite and fluorapatite. The results of these studies indicate that the dominant primary Ca-phosphate minerals on Mars possess higher solubilities that could lead to more than twice the phosphate concentration in solution. Dissolution rates for the Mars-relevant minerals derived in the study, when combined with the higher martian phosphorus abundance, could result in phosphate release rates of up to 45x faster for a given set of aqueous conditions on Mars when compared to Earth. The implications of the results for past or present martian habitability are discussed. In Chapter four, reactive transport modeling was applied to investigate the transport and mobility of phosphate under martian conditions. The kinetic and thermodynamic data derived in Chapter three were combined with Mars mission data, results from an investigation of Mars analog basalts at Craters of the Moon National Monument in Idaho, and previously published data to inform a reactive transport code and model dissolution profiles measured by Mars Exploration Rover (MER) Spirit in Wishstone class rocks. The modeling results suggest phosphate release into near-neutral waters occurred

  20. Consequences of Giant Impacts on the Martian dynamo

    NASA Astrophysics Data System (ADS)

    Monteux, J.; Amit, H.; Arkani-Hamed, J.; Choblet, G.; Langlais, B.; Tobie, G.; Johnson, C. L.; Jellinek, M.

    2015-12-01

    The Martian surface exhibits a strong dichotomy in elevation, crustal thickness and magnetization between the southern and northern hemispheres. A giant impact has been proposed to explain the formation of the Northern Lowlands on Mars. Such an impact probably led to strong and deep mantle heating and merging between the two cores. These processes will have implications on the thermal state and on the magnetic evolution of the planet. We model the effects of such an impact on the Martian magnetic field (1) by characterizing the thermochemical consequences of the sinking of the impactor's core as a single diapir, (2) by imposing a heat flux heterogeneity on the Martian core-mantle boundary (CMB). Our results show that large viscosity contrasts between the impactor's core and the surrounding mantle silicates can reduce the duration of the merging down to 1 kyr. Direct impact heating of Martian core favor thermal stratification of the core and core dynamo cessation. The merging of the impactor's core with the Martian core only delays the re-initiation of the dynamo for a very short time. While the core thermal stratification is likely to be evacuated rapidly, the impact induced thermal anomaly within the mantle is likely to remain stable for a longer timescale above the CMB. This thermal anomaly generates a large scale cooling heterogeneity at the CMB and a magnetic field dichotomy. A polar impactor leads to a north-south hemispheric magnetic dichotomy that is stronger than an east-west dichotomy created by an equatorial impactor. The amplitude of the magnetic dichotomy is mostly controlled by the horizontal Rayleigh number that represents the vigor of the convection driven by the lateral variations of the CMB heat flux. Our results imply that an impactor radius of 1000 km could have recorded the magnetic dichotomy observed in the Martian crustal field only if very rapid post-impact magma cooling took place.

  1. Earth Mars similarity criteria for exploring martian vehicles

    NASA Astrophysics Data System (ADS)

    Savu, G.

    2006-10-01

    In order to select the most efficient kind of a martian exploring vehicle, the similarity criteria are deduced from the equilibrium movement in the terrestrial and martian conditions. Different invariants have been obtained for the existing (entry capsules, parachutes and rovers) and potential martian exploring vehicles (lighter-than-air vehicle, airplane, helicopter and Mars Jumper). These similarity criteria, as non-dimensional numbers, allow to quickly compare if such kind of vehicles can operate in the martian environment, the movement performances, the necessary geometrical dimensions and the power consumption. Following this way of study it was concluded what vehicle is most suitable for the near soil Mars exploration. “Mars Rover” has less power consumption on Mars, but due to the rugged terrain the performances are weak. A vacuumed rigid airship is possible to fly with high performances and endurance on Mars, versus the impossibility of such a machine on the Earth. Due to very low density and the low Reynolds numbers in the Mars atmosphere, the power consumption for the martian airplane or helicopter is substantially higher. The most efficient vehicle for the Mars exploration seems to be a machine using the in situ non-chemical propellants: the 95% CO2 atmosphere and the weak solar radiation. A small compressor, electrically driven by photovoltaics, compresses the gas in a storage tank, in time. If the gas is expanded through a nozzle, sufficient lift and control forces are obtained for a VTOL flight of kilometers over the martian soil, in comparison with tens of meters of the actual Mars rovers.

  2. Earth-Mars similarity criteria for exploring martian vehicles

    NASA Astrophysics Data System (ADS)

    Savu, G.

    2003-11-01

    In order to select the most efficient kind of a martian exploring vehicle, the similarity criteria are deduced from the equilibrium movement in the terrestrial and martian conditions. Different invariants have been obtained for the existing (entry capsules, parachutes and rovers) and potential martian exploring vehicles (lighter-than-air vehicle, airplane, helicopter and Mars Jumper). These similarity criteria, as non dimensional numbers, allow to quickly compare if such a kind of vehicles can operate in the martian environment, the movement performances, the necessary geometrical dimensions and the power consumption. Following this way of study it was concluded what vehicle is most suitable for the near soil Mars exploration. "Mars Rover" has less power consumption on Mars, but due to the rugged terrain the performances are weak. A vacuumed rigid airship is possible to fly with high performances and endurance on Mars, versus the impossibility of such a machine on the Earth. Due to very low density and the low Reynolds numbers in the Mars atmosphere, the power consumption for the martian airplane or helicopter, is substantial higher. The most efficient vehicle for the Mars exploration it seems to be a machine using the in-situ non-chemical propellants: the 95% CO2 atmosphere and the weak solar radiation. A small compressor, electrically driven by photovoltaics, compresses the gas in a storage tank, in time. If the gas is expanded through a nozzle, sufficient lift and control forces are obtained for a VTOL flight of kilometers over the martian soil, in comparison with tens of meters of the actual Mars rovers.

  3. Volatile and other trace elements in Martian meteorites

    NASA Astrophysics Data System (ADS)

    Wang, Ming-Sheng; Mokos, Jennifer; Lipschutz, Michael E.

    1997-03-01

    We summarize RNAA data for 15 trace elements - U, Au, Co, Sb, Ga, Rb, Ag, Se, Cs, Te, Zn, Cd, Bi, Tl and In (in order of putative volatility during nebular condensation and accretion) - in 11 of the 12 known Martian meteorites. We have not yet measured Yamato 793605. Some shergottite data (Shergotty, Zagami, ALH A77005, EET A79001, LEW 88516) were published previously. Data for the six other Martian meteorites are new: the nakhlites and Chassigny samples studied were previously analyzed at NASA/JSC using INAA.

  4. Germination and growth of wheat in simulated Martian atmospheres

    NASA Astrophysics Data System (ADS)

    Schwartzkopf, Steven H.; Mancinelli, Rocco L.

    One design for a manned Mars base incorporates a bioregenerative life support system based upon growing higher plants at a low atmospheric pressure in a greenhouse on the Martian surface. To determine the concept's feasibility, the germination and initial growth of wheat ( Triticum aestivum) was evaluated at low atmospheric pressures in simulated Martian atmosphere (SMA) and in SMA supplemented with oxygen. Total atmospheric pressures ranged from 10 to 1013 mb. No seeds germinated in pure SMA, regardless of atmospheric pressure. In SMA plus oxygen at 60 mb total pressure, germination and growth occurred but were lower than in the Earth atmosphere controls.

  5. Martian thermosphere-exosphere temperatures from SPICAM dayglow measurements

    NASA Astrophysics Data System (ADS)

    Stiepen, A.; Gérard, J.-C.; Bougher, S.; Montmessin, F.

    2013-09-01

    We analyze the ultraviolet dayglow in the atmosphere of Mars through CO2+ and CO Cameron emissions. These emissions are accumulated on a large dataset of dayside grazing limb performed by the Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM) instrument on board the Mars Express spacecraft. The temperature of the Martian high atmosphere can be retrieved from these limb emission profiles. Its variability with season, latitude, solar activity and the crustal magnetic field is discussed. We use a one-dimensional chemical-diffusive model to retrieve the main features of the emissions and constrain the temperature and density vertical profiles of the main components of the Martian atmosphere.

  6. Distribution and Orientation of Alluvial Fans in Martian Craters

    NASA Technical Reports Server (NTRS)

    Kraal, E. R.; Moore, J. M.; Howard, A. D.; Asphaug, E. I.

    2005-01-01

    We present the results of the complete survey of Martian alluvial fans from 0-30 S, initiated by Moore and Howard. Nineteen impact craters contain alluvial fans. They are regionally grouped into three distinct areas. We present our initial results regarding their distribution and orientation in order to understand what controls their formation. Since alluvial fans are formed by water transport of sediment, these features record wetter episodes of Martian climate. In addition, their enigmatic distribution (in regional groups and in some craters, but not similar adjacent ones) needs to be understood, to see how regional geology, topographic characteristics, and/or climate influence their formation and distribution.

  7. Germination and growth of wheat in simulated Martian atmospheres.

    PubMed

    Schwartzkopf, S H; Mancinelli, R L

    1991-01-01

    One design for a manned Mars base incorporates a bioregenerative life support system based upon growing higher plants at a low atmospheric pressure in a greenhouse on the Martian surface. To determine the concept's feasibility, the germination and initial growth of wheat (Triticum aestivum) was evaluated at low atmospheric pressures in simulated Martian atmosphere (SMA) and in SMA supplemented with oxygen. Total atmospheric pressures ranged from 10 to 1013 mb. No seeds germinated in pure SMA, regardless of atmospheric pressure. In SMA plus oxygen at 60 mb total pressure, germination and growth occurred but were lower than in the Earth atmosphere controls.

  8. Germination and growth of wheat in simulated Martian atmospheres

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.; Mancinelli, Rocco L.

    1991-01-01

    One design for a manned Mars base incorporates a bioregenerative life support system based upon growing higher plants at a low atmospheric pressure in a greenhouse on the Martian surface. To determine the concept's feasibility, the germination and initial growth of wheat (Triticum aestivum) was evaluated at low atmospheric pressures in simulated Martian atmosphere (SMA) and in SMA supplemented with oxygen. Total atmospheric pressures ranged from 10 to 1013 mb. No seeds germinated in pure SMA, regardless of atmospheric pressure. In SMA plus oxygen at 60 mb total pressure, germination and growth occurred but were lower than in the earth atmosphere controls.

  9. Martian Swarm Exploration and Mapping Using Laser Slam

    NASA Astrophysics Data System (ADS)

    Nowak, S.; Krüger, T.; Matthaei, J.; Bestmann, U.

    2013-08-01

    In order to explore planet Mars in detail and search for extra-terrestrial life the observation from orbit is not sufficient. To realize complex exploration tasks the use of automatic operating robots with a robust fault-tolerant method of navigation, independent of any infrastructure is a possibility. This work includes a concept of rotary-wing Unmanned Aerial Vehicles (UAVs) and Unmanned Ground Vehicles (UGVs) for Martian exploration in a swarm. Besides the scenario of Martian surrounding, with a small number of distinctive landmarks, the challenge consists of a Simultaneous Localization and Mapping (SLAM) concept using laser data of all swarm members.

  10. Survival of microorganisms in smectite clays - Implications for Martian exobiology

    NASA Technical Reports Server (NTRS)

    Moll, Deborah M.; Vestal, J. R.

    1992-01-01

    The survival of Baccillus subtilis, Azotobacter chroococcum, and the enteric bacteriophage MS2 has been examined in clays representing terrestrial (Wyoming type montmorillonite) and Martian (Fe3+ montmorillonite) soils exposed to terrestrial and Martian environmental conditions of temperature and atmospheric composition and pressure. An important finding is that MS2 survived simulated Mars conditions better than the terrestrial environment, probably owing to stabilization of the virus caused by the cold and dry conditions of the simulated Mars environment. This finding, the first published indication that viruses may be able to survive in Mars-type soils, may have important implications for future missions to Mars.

  11. Germination and growth of wheat in simulated Martian atmospheres.

    PubMed

    Schwartzkopf, S H; Mancinelli, R L

    1991-01-01

    One design for a manned Mars base incorporates a bioregenerative life support system based upon growing higher plants at a low atmospheric pressure in a greenhouse on the Martian surface. To determine the concept's feasibility, the germination and initial growth of wheat (Triticum aestivum) was evaluated at low atmospheric pressures in simulated Martian atmosphere (SMA) and in SMA supplemented with oxygen. Total atmospheric pressures ranged from 10 to 1013 mb. No seeds germinated in pure SMA, regardless of atmospheric pressure. In SMA plus oxygen at 60 mb total pressure, germination and growth occurred but were lower than in the Earth atmosphere controls. PMID:11537561

  12. Formation of Martian Gullies by the Action of Liquid Water Flowing Under Current Martian Environmental Conditions

    NASA Technical Reports Server (NTRS)

    Heldmann, J. L.; Toon, O. B.; Pollard, W. H.; Mellon, M. T.; Pitlick, J.; McKay, C. P.; Andersen, D. T.

    2005-01-01

    Images from the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft show geologically young small-scale features resembling terrestrial water-carved gullies. An improved understanding of these features has the potential to reveal important information about the hydrological system on Mars, which is of general interest to the planetary science community as well as the field of astrobiology and the search for life on Mars. The young geologic age of these gullies is often thought to be a paradox because liquid water is unstable at the Martian surface. Current temperatures and pressures are generally below the triple point of water (273 K, 6.1 mbar) so that liquid water will spontaneously boil and/or freeze. We therefore examine the flow of water on Mars to determine what conditions are consistent with the observed features of the gullies.

  13. Biological space experiments for the simulation of Martian conditions: UV radiation and Martian soil analogues

    NASA Astrophysics Data System (ADS)

    Rettberg, P.; Rabbow, E.; Panitz, C.; Horneck, G.

    2004-01-01

    The survivability of resistant terrestrial microbes, bacterial spores of Bacillus subtilis, was investigated in the BIOPAN facility of the European Space Agency onboard of Russian Earth-orbiting FOTON satellites (BIOPAN I -III missions). The spores were exposed to different subsets of the extreme environmental parameters in space (vacuum, extraterrestrial solar UV, shielding by protecting materials like artificial meteorites). The results of the three space experiments confirmed the deleterious effects of extraterrestrial solar UV radiation which, in contrast to the UV radiation reaching the surface of the Earth, also contains the very energy-rich, short wavelength UVB and UVC radiation. Thin layers of clay, rock or meteorite material were shown to be only successful in UV-shielding, if they are in direct contact with the spores. On Mars the UV radiation climate is similar to that of the early Earth before the development of a protective ozone layer in the atmosphere by the appearance of the first aerobic photosynthetic bacteria. The interference of Martian soil components and the intense and nearly unfiltered Martian solar UV radiation with spores of B. subtilis will be tested with a new BIOPAN experiment, MARSTOX. Different types of Mars soil analogues will be used to determine on one hand their potential toxicity alone or in combination with solar UV (phototoxicity) and on the other hand their UV protection capability. Two sets of samples will be placed under different cut-off filters used to simulate the UV radiation climate of Mars and Earth. After exposure in space the survival of and mutation induction in the spores will be analyzed at the DLR, together with parallel samples from the corresponding ground control experiment performed in the laboratory. This experiment will provide new insights into the principal limits of life and its adaptation to environmental extremes on Earth or other planets which and will also have implications for the potential for the

  14. Biological space experiments for the simulation of Martian conditions: UV radiation and Martian soil analogues.

    PubMed

    Rettberg, P; Rabbow, E; Panitz, C; Horneck, G

    2004-01-01

    The survivability of resistant terrestrial microbes, bacterial spores of Bacillus subtilis, was investigated in the BIOPAN facility of the European Space Agency onboard of Russian Earth-orbiting FOTON satellites (BIOPAN I -III missions). The spores were exposed to different subsets of the extreme environmental parameters in space (vacuum, extraterrestrial solar UV, shielding by protecting materials like artificial meteorites). The results of the three space experiments confirmed the deleterious effects of extraterrestrial solar UV radiation which, in contrast to the UV radiation reaching the surface of the Earth, also contains the very energy-rich, short wavelength UVB and UVC radiation. Thin layers of clay, rock or meteorite material were shown to be only successful in UV-shielding, if they are in direct contact with the spores. On Mars the UV radiation climate is similar to that of the early Earth before the development of a protective ozone layer in the atmosphere by the appearance of the first aerobic photosynthetic bacteria. The interference of Martian soil components and the intense and nearly unfiltered Martian solar UV radiation with spores of B. subtilis will be tested with a new BIOPAN experiment, MARSTOX. Different types of Mars soil analogues will be used to determine on one hand their potential toxicity alone or in combination with solar UV (phototoxicity) and on the other hand their UV protection capability. Two sets of samples will be placed under different cut-off filters used to simulate the UV radiation climate of Mars and Earth. After exposure in space the survival of and mutation induction in the spores will be analyzed at the DLR, together with parallel samples from the corresponding ground control experiment performed in the laboratory. This experiment will provide new insights into the principal limits of life and its adaptation to environmental extremes on Earth or other planets which and will also have implications for the potential for the

  15. Looking for Fossil Bacteria in Martian Materials

    NASA Technical Reports Server (NTRS)

    Westall, F.; Walsh, M. M.; Mckay, D. D.; Wentworth, S.; Gibson, E. K.; Steele, A.; Toporski, J.; Lindstrom, D.; Martinez, R.; Allen, C. C.

    1999-01-01

    The rationale for looking for prokaryote fossils in Martian materials is based on our present understanding of the environmental evolution of that planet in comparison to the history of the terrestrial environments and the development and evolution of life on Earth. On Earth we have clear, albeit indirect, evidence of life in 3.8 b.y.-old rocks from Greenland and the first morphological fossils in 3.3-3.5 b.y.-old cherts from South Africa and Australia. In comparison, Mars, being smaller, probably cooled down after initial aggregation faster than the Earth. Consequently, there could have been liquid water on its surface earlier than on Earth. With a similar exogenous and endogenous input of organics and life-sustaining nutrients as is proposed for the Earth, life could have arisen on that planet, possibly slightly earlier dm it did on Earth. Whereas on Earth liquid water has remained at the surface of the planet since about 4.4 b.y. (with some possible interregnums caused by planet-sterilising impacts before 3.8. b.y. and perhaps a number of periods of a totally frozen Earth, this was not the case with Mars. Although it is not known exactly when surficial water disappeared from the surface, there would have been sufficient time for life to have developed into something similar to the terrestrial prokaryote stage. However, given the earlier environmental deterioration, it is unlikely that it evolved into the eukaryote stage and even evolution of oxygenic photosynthesis may not have been reached. Thus, the impetus of research is on single celled life simnilar to prokaryotes. We are investigating a number of methods of trace element analysis with respect to the Early Archaean microbial fossils. Preliminary neutron activation analysis of carbonaceous layers in the Early Archaean cherts from South Africa and Australia shows some partitioning of elements such as As, Sb, Cr with an especial enrichment of lanthanides in a carbonaceous-rich banded iron sediment . More

  16. Martian paleomagnetism with the SQUID microscope

    NASA Astrophysics Data System (ADS)

    Weiss, Benjamin Paul

    an apparently ancient martian atmosphere. Because this gas is enriched in light isotopes of H and N relative to that on present-day Mars, this supports the hypothesis that the planet has experienced significant atmospheric loss since 4 Ga. These calculations also suggest that for the last 4 Gyr, average surface temperatures on Mars may not have been much higher than the present cold conditions.

  17. Martian Dust Devil Movie, Phoenix Sol 104

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Surface Stereo Imager on NASA's Phoenix Mars Lander caught this dust devil in action west of the lander in four frames shot about 50 seconds apart from each other between 11:53 a.m. and 11:56 a.m. local Mars time on Sol 104, or the 104th Martian day of the mission, Sept. 9, 2008.

    Dust devils have not been detected in any Phoenix images from earlier in the mission, but at least six were observed in a dozen images taken on Sol 104.

    Dust devils are whirlwinds that often occur when the Sun heats the surface of Mars, or some areas on Earth. The warmed surface heats the layer of atmosphere closest to it, and the warm air rises in a whirling motion, stirring dust up from the surface like a miniature tornado.

    The dust devil visible in this sequence was about 1,000 meters (about 3,300 feet) from the lander when the first frame was taken, and had moved to about 1,700 meters (about 5,600 feet) away by the time the last frame was taken about two and a half minutes later. The dust devil was moving westward at an estimated speed of 5 meters per second (11 miles per hour), which is similar to typical late-morning wind speed and direction indicated by the telltale wind gauge on Phoenix.

    This dust devil is about 5 meters (16 feet) in diameter. This is much smaller than dust devils that have been observed by NASA's Mars Exploration Rover Spirit much closer to the equator. It is closer in size to dust devils seen from orbit in the Phoenix landing region, though still smaller than those..

    The image has been enhanced to make the dust devil easier to see. Some of the frame-to-frame differences in the appearance of foreground rocks is because each frame was taken through a different color filter.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  18. Electrostatic fields in a dusty Martian environment

    NASA Technical Reports Server (NTRS)

    Sentman, D. D.

    1991-01-01

    While there have been several studies suggesting the possibility of electrical activity on Mars, to date there have been no measurements to search for evidence of such activity. In the absence of widespread water clouds and convective storm systems similar to those on the Earth and Jupiter, the most likely candidate for the creation of electrostatic charges and fields is triboelectric charging of dust, i.e., the friction between blown dust and the ground, and of dust particles with each other. Terrestrial experience demonstrates that electric fields 5 to 15 kV-m(exp -1) are not uncommon in dust storms and dust devils in desert regions, where the polarity varies according to the chemical composition and grain size. Simple laboratory experiments have demonstrated that modest electrostatic fields of roughly 5,000 V-m(exp -1) may be produced, along with electrical spark discharges and glow discharges, in a simulation of a dusty, turbulent Martian surface environment. While the Viking landers operated for several years with no apparent deleterious effects from electrostatic charging, this may have been at least partly due to good engineering design utilizing pre-1976 electronic circuitry to minimize the possibility of differential charging among the various system components. However, free roaming rovers, astronauts, and airborne probes may conceivably encounter an environment where electrostatic charging is a frequent occurrence, either by way of induction from a static electric field or friction with the dusty surface and atmosphere. This raises the possibility of spark discharges or current surges when subsequent contact is made with other pieces of electrical equipment, and the possibility of damage to modern microelectronic circuitry. Measurements of electrostatic fields on the surface of Mars could therefore be valuable for assessing this danger. Electric field measurements could also be useful for detecting natural discharges that originate in dust storms. This

  19. A comprehensive database of Martian landslides

    NASA Astrophysics Data System (ADS)

    Battista Crosta, Giovanni; Vittorio De Blasio, Fabio; Frattini, Paolo; Valbuzzi, Elena

    2016-04-01

    During a long-term project, we have identified and classified a large number (> 3000) of Martian landslides especially but not exclusively from Valles Marineris. This database provides a more complete basis for a statistical study of landslides on Mars and its relationship with geographical and environmental conditions. Landslides have been mapped according to standard geomorphological criteria, delineating both the landslide scar and accumulation limits, associating each scarp to a deposit, and using the program ArcGis for generation of a complete digital dataset. Multiple accumulations from the same source area or from different sources have been differentiated, where possible, to obtain a more complete dataset and to allow more refined analyses. Each landslide has been classified according to a set of criteria including: type, degree of confinement, possible trigger, elevation with respect to datum, geomorphological features, degree of multiplicity, and so on. The runout, fall height, and volume have been measured for each deposit. In fact, the database is revealing a series of trends that may assist at understanding landform processes on Mars and its past climatic conditions. One of the most interesting aspects of our dataset is the presence of a population of landslides whose particularly long mobility deviates from average behavior. While some landslides have travelled unimpeded on a usually flat area, others have travelled against obstacles or mounds. Therefore, landslides are also studied in relation to i) morphologies created by the landslide itself, ii) presence of mounds, barriers or elevations than have affected the movement of the landslide mass. In some extreme cases, the landslide was capable of travelling for several tens of km along the whole valley and upon reaching the opposite side it travelled upslope for several hundreds of meters, which is indication of high travelling speed. In other cases, the high speed is revealed by dynamic deformations

  20. Radar Reflectivity of the Martian Polar Regions

    NASA Technical Reports Server (NTRS)

    Butler, B. J.; Slade, M. A.; Muhleman, D. O.

    2000-01-01

    Radar experiments provide a unique method of probing the surfaces and subsurfaces of planetary bodies. Information on surface and subsurface structures and properties can be extracted from radar data. There is a well developed history of radar investigations of the planet Mars, beginning with the first reports of variations of scattering properties as a function of martian longitude in the mid-1960's. Because of the rapid rotation of Mars, the standard technique of delay-doppler mapping cannot be used as effectively as it is on Mercury and Venus, making it a more difficult radar target. Techniques have been developed to overcome this difficulty, including an inversion technique to combine many doppler-only (CW) experiments from different viewing geometries into a map of surface reflectivity, and new random long-code techniques. These techniques still suffer from ambiguities, however. A third technique which does not suffer from these ambiguities is the combination of the powerful Goldstone transmitter with the VLA as the receiving instrument to create a combined radar imaging instrument. We have used this combined radar instrument to image the surface of Mars in 3.5-cm radar reflectivity during the 1988, 1992/93, and 1999 oppositions. During the 1988 experiments, the residual south polar ice cap (RSPIC) was the brightest radar reflector on the planet - intrinsically brighter than even the Tharsis lava flows. This was quite an unexpected result. In contrast, during the 1992/93 experiments, the residual north polar ice cap (RNPIC) was not nearly so bright, and in fact showed no enhancement at all, This was puzzling, given the 1988 results for the RSPIC. We attributed the lack of a radar reflection enhancement to a combination of three effects: the geometry was different; the season was different; and the intrinsic scattering from the residual ice caps was different. The 1999 experiments provided a chance to test the relative importance of these three effects, since

  1. Tracer transport in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Lian, Y.; Richardson, M. I.; Newman, C. E.; Lee, C.; Toigo, A. D.; Campin, J.

    2011-12-01

    Transport is crucial to understanding and reproducing the Martian dust and water cycles, and to interpreting putative methane and other trace gas (e.g. Argon) observations. However, as quantified by comparing model predictions with Argon measurements made by the Gamma Ray Spectrometer [e.g. Sprague et al., 2004, 2007], current Mars general circulation models (GCM's) appear to do a poor job at tracer transport [e.g. Nelli et al., 2007]. This invalidates a core assumption of GCM modeling in the last decade - that transport is sufficiently well treated in models that we need focus only on improving physical parameterizations, and that differences between results from different GCM's stem purely from their treatment of physical processes. If instead it is the simulated dynamical processes that need better treatment we need to move towards higher-quality numerics, e.g. based on the finite volume formulation, and introduce a more sophisticated approach to advection following work done for terrestrial chemical transport modeling. Here we present the results of non-condensable tracer transport simulations using our newly developed Mars MITgcm, which has both of the aforementioned desirable attributes: a finite volume core and access to a range of sophisticated advection schemes. Our results are encouraging in that we are able to reproduce the observed peak polar Argon enhancement factor of six (about double that attainable with most other Mars GCMs). Our diagnostics show that the time-averaged zonal-mean advection produces net increases of Argon at the winter poles, while stationary and transient eddies transport Argon away from the poles. Using less diffusive nonlinear advection schemes with flux limiters tends to produce more advective fluxes of tracers into the southern winter pole than the more diffusive linear advection schemes, resulting in a greater net increase of polar Argon abundance. We further utilize a more realistic k-distribution radiative transfer model, an

  2. Pyroxenes in Martian meteorites as petrogenetic indicators

    NASA Technical Reports Server (NTRS)

    McKay, Gordon; Le, L.; Mikouchi, T.; Makishima, J.; Schwandt, C.

    2006-01-01

    Pyroxenes in Martian meteorites are important recorders of petrogenetic processes. Understanding the details of pyroxene major and minor element compositional variations can provide important insights into those processes. A combination of careful petrographic analysis of natural samples and experimental crystallization studies can lead to better understanding of the processes that gave rise to these samples on Mars. In addition, experimentally determined major, minor and trace element partition coefficients are important for using natural pyroxenes to estimate the compositions of the melts from which they crystallized and the oxidation conditions that prevailed during crystallization. We will report on minor element (Al, Ti, Cr) zoning in nakhlite pyroxenes and in synthetic pyroxenes that we have grown for the purposes of determining pyroxene/melt partition coefficients for Sr and REE. The natural pyroxenes have patchy Al zoning that, by analogy with our experimental pyroxenes, we interpret as sector zoning. The irregular patchy nature of the zoning is probably the result of the vagaries of growth kinetics and local environment during crystal growth. More slowly cooled nakhlites have the most distinct bimodal zoning, with one mode having Al2O3 around 0.5-0.6 wt%, and the other around 0.9 %. Average Al content increases with increasing cooling rate. This feature is puzzling, since the cumulus pyroxenes were almost certainly present at the time of eruption. Al and Ti are strongly correlated, but Cr is completely decoupled from those elements. The synthetic pyroxenes are distinctly sector zoned in Al and Ti, and the sector-to-sector variation in Al within a single crystal has important effects on trace element partition coefficients. Trivalent REE are strongly correlated with Al, while divalent elements (Sr, Eu+2) show a significantly weaker correlation. For example, as the Al2O3 content varies from 0.3 to 0.6 wt % from one sector to another, D(Gd) increases by

  3. What Lies Below a Martian Ice Cap

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for larger annotated version

    This image (top) taken by the Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter reveals the layers of ice, sand and dust that make up the north polar ice cap on Mars. It is the most detailed look to date at the insides of this ice cap. The colored map below the radar picture shows the topography of the corresponding Martian terrain (red and white represent higher ground, and green and yellow lower).

    The radar image reveals four never-before-seen thick layers of ice and dust separated by layers of nearly pure ice. According to scientists, these thick ice-free layers represent approximately one-million-year-long cycles of climate change on Mars caused by variations in the planet's tilted axis and its eccentric orbit around the sun. Adding up the entire stack of ice gives an estimated age for the north polar ice cap of about 4 million years a finding that agrees with previous theoretical estimates. The ice cap is about 2 kilometers (1.2 miles) thick.

    The radar picture also shows that the boundary between the ice layers and the surface of Mars underneath is relatively flat (bottom white line on the right). This implies that the surface of Mars is not sagging, or bending, under the weight of the ice cap and this, in turn, suggests that the planet's lithosphere, a combination of the crust and the strong parts of the upper mantle, is thicker than previously thought.

    A thicker lithosphere on Mars means that temperatures increase more gradually with depth toward the interior. Temperatures warm enough for water to be liquid are therefore deeper than previously thought. Likewise, if liquid water does exist in aquifers below the surface of Mars, and if there are any organisms living in that water, they would have to be located deeper in the planet.

    The topography data are from Mars Orbiter Laser Altimeter, which was flown on NASA's Mars Global

  4. Martian fluid and Martian weathering signatures identified in Nakhla, NWA 998 and MIL 03346 by halogen and noble gas analysis

    NASA Astrophysics Data System (ADS)

    Cartwright, J. A.; Gilmour, J. D.; Burgess, R.

    2013-03-01

    We report argon (Ar) noble gas, Ar-Ar ages and halogen abundances (Cl, Br, I) of Martian nakhlites Nakhla, NWA 998 and MIL 03346 to determine the presence of Martian hydrous fluids and weathering products. Neutron-irradiated samples were either crushed and step-heated (Nakhla only), or simply step-heated using a laser or furnace, and analysed for noble gases using an extension of the 40Ar-39Ar technique to determine halogen abundances. The data obtained provide the first isotopic evidence for a trapped fluid that is Cl-rich, has a strong correlation with 40ArXS (40ArXS = 40Armeasured - 40Arradiogenic) and displays 40ArXS/36Ar of ˜1000 - consistent with the Martian atmosphere. This component was released predominantly in the low temperature and crush experiments, which may suggest a fluid inclusion host. For the halogens, we observe similar Br/Cl and I/Cl ratios between the nakhlites and terrestrial reservoirs, which is surprising given the absence of crustal recycling, organic matter and frequent fluid activity on Mars. In particular, Br/Cl ratios in our Nakhla samples (especially olivine) are consistent with previously analysed Martian weathering products, and both low temperature and crush analyses show a similar trend to the evaporation of seawater. This may indicate that surface brines play an important role on Mars and on halogen assemblages within Martian meteorites and rocks. Elevated I/Cl ratios in the low temperature NWA 998 and MIL 03346 releases may relate to in situ terrestrial contamination, though we are unable to distinguish between low temperature terrestrial or Martian components. Whilst estimates of the amount of water present based on the 36Ar concentrations are too high to be explained by a fluid component alone, they are consistent with a mixed-phase inclusion (gas and fluid) or with shock-implanted Martian atmospheric argon. The observed fluid is dilute (low salinity, but high Br/Cl and I/Cl ratios), contains a Martian atmospheric component

  5. Albedo Study of the Depositional Fans Associated with Martian Gullies

    NASA Astrophysics Data System (ADS)

    Craig, J.; Sears, D. W. G.

    2005-03-01

    This work is a two-part investigation of the albedo of the depositional aprons or fans associated with Martian gully features. Using Adobe Systems Photoshop 5.0 software we analyzed numerous Mars Global Surveyor MOC and Mars Odyssey THEMIS images.

  6. CIRs Observed by MSL/RAD on the Martian Surface

    NASA Astrophysics Data System (ADS)

    Lohf, Henning; Zeitlin, Cary; Rafkin, Scot; Koehler, Jan; Posner, Arik; Hassler, Donald M.; Heber, Bernd; Ehresmann, Bent; Wimmer-Schweingruber, Robert; Guo, Jingnan; Appel, Jan Kristoffer

    2016-07-01

    Co-rotating Interaction Regions (CIRs) are recurrent Stream Interaction Regions in the solar wind which are stable transient plasma structures lasting several solar rotations. They can modulate Galactic Cosmic Rays (GCRs) and to some extent result in a modulation of GCR induced secondary energetic particles on the Martian surface. The Mars Science Laboratory/ Radiation Assessment Detector (MSL/RAD) has been measuring the Martian Surface Radiation Environment for more than three years and observes this modulation effect. We will show that the effect of CIRs can be measured on the Martian surface with MSL/RAD and this can be used to derive the arrival times of CIRs at Mars. These can provide (limited) solar wind plasma properties in the vicinity of Mars and thus serve as important constraints for modeling atmospheric response to variations in the solar wind. We use multi spacecraft observations of the solar wind and compare them with the heliospheric MHD Model ENLIL to verify that a certain class of dose rate variation we see on the Martian surface is due to CIRs. We use ballistic back-mapping as well as a time-shift algorithm to map the plasma properties measured at individual spacecraft locations and times to Mars. We compare these predictions with those of the CCMC ENLIL heliospheric MHD simulations.

  7. Comment on 'Propellant production from the Martian atmosphere'

    NASA Technical Reports Server (NTRS)

    Ruppe, H. O.

    1993-01-01

    The optimism of the Tauber et al. (1992) note on photosynthetic production of spacecraft fuels from Martian atmospheric gases is presently noted, in conjunction with the need for prior missions' verification of such a system. Two of the original authors reply that their solar cell array assumptions are conservative in light of plausible performance projections for 2010-decade technology.

  8. Intra-Annual Variations of the Martian Swiss Cheese Terrain

    NASA Astrophysics Data System (ADS)

    Titus, T. N.; Cushing, G.; Pathare, A.; Christensen, P. R.; Byrne, S.; Ivanov, A. B.; Ingersoll, A.; Richardson, M.; Kirk, R. L.; Soderblom, L. A.; Themis Team

    2004-03-01

    Much of the surface of the carbon dioxide South Polar Residual Cap of Mars consists of quasi-circular pits with steep walls that have been dubbed "Swiss Cheese" terrain. Here, we examine the intra-annual variations of the Martian Swiss Cheese terrain using both MOC and THEMIS VIS/IR imaging.

  9. Slope histogram distribution-based parametrisation of Martian geomorphic features

    NASA Astrophysics Data System (ADS)

    Balint, Zita; Székely, Balázs; Kovács, Gábor

    2014-05-01

    The application of geomorphometric methods on the large Martian digital topographic datasets paves the way to analyse the Martian areomorphic processes in more detail. One of the numerous methods is the analysis is to analyse local slope distributions. To this implementation a visualization program code was developed that allows to calculate the local slope histograms and to compare them based on Kolmogorov distance criterion. As input data we used the digital elevation models (DTMs) derived from HRSC high-resolution stereo camera image from various Martian regions. The Kolmogorov-criterion based discrimination produces classes of slope histograms that displayed using coloration obtaining an image map. In this image map the distribution can be visualized by their different colours representing the various classes. Our goal is to create a local slope histogram based classification for large Martian areas in order to obtain information about general morphological characteristics of the region. This is a contribution of the TMIS.ascrea project, financed by the Austrian Research Promotion Agency (FFG). The present research is partly realized in the frames of TÁMOP 4.2.4.A/2-11-1-2012-0001 high priority "National Excellence Program - Elaborating and Operating an Inland Student and Researcher Personal Support System convergence program" project's scholarship support, using Hungarian state and European Union funds and cofinances from the European Social Fund.

  10. Terrestrial glacial eskers: Analogs for Martian sinuous ridges

    NASA Technical Reports Server (NTRS)

    Kargel, Jeffrey S.; Strom, Roger G.

    1991-01-01

    A glacial model was introduced last year for the Argyre region, a concept which is now extended, and which was recently integrated with a Global Hydrologic Model incorporating many other aspects of Martian geology. Despite wide agreement that the Martian ridges strongly resemble glacial eskers, this hypothesis has been presented with great equivocation due to a perceived lack of other glacial landforms. Quite to the contrary, it is shown that the Martian ridges actually do occur in logical ordered sequences with many other types of characteristically glacial appearing landforms. Herein, the esker hypothesis is further supported in isolation from considerations of regional landform assemblages. It is concluded that Martian sinuous ridges are similar in every respect to terrestrial eskers: scale, morphology, planimetric pattern, and associations with other probable glaciogenic landforms. It is found that the esker hypothesis is well supported. Eskers are glaciofluvial structures, and owe their existence to large scale melting of stagnant temporate glaciers. Thus, eskers are indicators of an ameliorating climatic regime after a protracted episode of cold, humid conditions.

  11. The Martian Water Cycle Based on 3-D Modeling

    NASA Technical Reports Server (NTRS)

    Houben, H.; Haberle, R. M.; Joshi, M. M.

    1999-01-01

    Understanding the distribution of Martian water is a major goal of the Mars Surveyor program. However, until the bulk of the data from the nominal missions of TES, PMIRR, GRS, MVACS, and the DS2 probes are available, we are bound to be in a state where much of our knowledge of the seasonal behavior of water is based on theoretical modeling. We therefore summarize the results of this modeling at the present time. The most complete calculations come from a somewhat simplified treatment of the Martian climate system which is capable of simulating many decades of weather. More elaborate meteorological models are now being applied to study of the problem. The results show a high degree of consistency with observations of aspects of the Martian water cycle made by Viking MAWD, a large number of ground-based measurements of atmospheric column water vapor, studies of Martian frosts, and the widespread occurrence of water ice clouds. Additional information is contained in the original extended abstract.

  12. Strategic Planning for Exploration of the Martian Subsurface

    NASA Technical Reports Server (NTRS)

    Beaty, D. W.; Briggs, G.; Clifford, S. M.

    2000-01-01

    Exploration of the upper 2-5 km of the martian crust (i.e. the portion that we can realistically envision physically accessing) is a tantalizing prospect. This may provide our best opportunity to advance the three current objectives of the Mars exploration program: Life, Climate, and Resources, with a common theme of water.

  13. Modeling the development of martian sublimation thermokarst landforms

    NASA Astrophysics Data System (ADS)

    Dundas, Colin M.; Byrne, Shane; McEwen, Alfred S.

    2015-12-01

    Sublimation-thermokarst landforms result from collapse of the surface when ice is lost from the subsurface. On Mars, scalloped landforms with scales of decameters to kilometers are observed in the mid-latitudes and considered likely thermokarst features. We describe a landscape evolution model that couples diffusive mass movement and subsurface ice loss due to sublimation. Over periods of tens of thousands of Mars years under conditions similar to the present, the model produces scallop-like features similar to those on the martian surface, starting from much smaller initial disturbances. The model also indicates crater expansion when impacts occur in surfaces underlain by excess ice to some depth, with morphologies similar to observed landforms on the martian northern plains. In order to produce these landforms by sublimation, substantial quantities of excess ice are required, at least comparable to the vertical extent of the landform, and such ice must remain in adjacent terrain to support the non-deflated surface. We suggest that martian thermokarst features are consistent with formation by sublimation, without melting, and that significant thicknesses of very clean excess ice (up to many tens of meters, the depth of some scalloped depressions) are locally present in the martian mid-latitudes. Climate conditions leading to melting at significant depth are not required.

  14. Modeling the development of martian sublimation thermokarst landforms

    USGS Publications Warehouse

    Dundas, Colin M.; Byrne, Shane; McEwen, Alfred S.

    2015-01-01

    Sublimation-thermokarst landforms result from collapse of the surface when ice is lost from the subsurface. On Mars, scalloped landforms with scales of decameters to kilometers are observed in the mid-latitudes and considered likely thermokarst features. We describe a landscape evolution model that couples diffusive mass movement and subsurface ice loss due to sublimation. Over periods of tens of thousands of Mars years under conditions similar to the present, the model produces scallop-like features similar to those on the Martian surface, starting from much smaller initial disturbances. The model also indicates crater expansion when impacts occur in surfaces underlain by excess ice to some depth, with morphologies similar to observed landforms on the Martian northern plains. In order to produce these landforms by sublimation, substantial quantities of excess ice are required, at least comparable to the vertical extent of the landform, and such ice must remain in adjacent terrain to support the non-deflated surface. We suggest that Martian thermokarst features are consistent with formation by sublimation, without melting, and that significant thicknesses of very clean excess ice (up to many tens of meters, the depth of some scalloped depressions) are locally present in the Martian mid-latitudes. Climate conditions leading to melting at significant depth are not required.

  15. Development of a Charged Particle Detector for Windborne Martian Dust

    NASA Technical Reports Server (NTRS)

    Calle, C. I.; Mantovani, J. G.; Groop, E. E.; Buehler, M. G.; Buhler, C. R.; Nowicki, A. W.

    2002-01-01

    A prototype of an aerodynamic electrometer to measure the electrostatic properties of Martian atmospheric dust has been constructed. The instrument will enable a more thorough understanding of the potential for electrostatic discharge of different materials on Mars. Additional information is contained in the original extended abstract.

  16. Martian Atmospheric Dust Mitigation for ISRU Intakes via Electrostatic Precipitation

    NASA Technical Reports Server (NTRS)

    Phillips, James R., III; Pollard, Jacob R. S.; Johansen, Michael R.; Mackey, Paul J.; Clements, Sid; Calle, Carlos I.

    2016-01-01

    This document is the presentation to be given at the 2016 American Society of Civil Engineers Earth and Space Conference to examine the concept of using electrostatic precipitation for Martian atmospheric dust mitigation of the intakes of in-situ resource utilization reactors.

  17. Simulation of the UV-radiation at the Martian surface

    NASA Astrophysics Data System (ADS)

    Kolb, C.; Stimpfl, P.; Krenn, H.; Lammer, H.; Kargl, G.; Abart, R.; Patel, M. R.

    The UV-radiation at the Martian surface is for several reasons of importance. UV radiation can cause specific damages in the DNA-containing living systems and is involved in the formation of catalytically produced oxidants such as superoxide ions and peroxides. These are capable to oxidize and subsequently destroy organic matter. Lab simulations are necessary to investigate and understand the effects of organic matter removal at the Martian surface. We designed a radiation apparatus which simulates the solar spectrum at the Martian surface between 200 and 700 nm. The system consists of an UV-enhanced xenon arc lamp and special exchangeable filter-sets and mirrors for simulating the effects of the Martian atmospheric column and dust loading. A special collimating system bundles the final parallel beam so that the intensity at the target spot is independent from the distance between the ray source and the sample. The system was calibrated by means of an optical photo-spectrometer to align the ray output with the theoretical target spectrum and to ensure spectral homogeneity. We present preliminary data on calibration and performance of our system, which is integrated in the Austrian Mars simulation facility.

  18. Martian-Solar Wind Interaction Boundaries as Observed by MAVEN

    NASA Astrophysics Data System (ADS)

    Gruesbeck, J.; Espley, J. R.; Connerney, J. E. P.; DiBraccio, G. A.; Soobiah, Y. I. J.

    2015-12-01

    Lacking a global intrinsic field, the Martian magnetosphere is a product of the interaction of Mars with the interplanetary magnetic field and the supersonic solar wind. Previous analysis has been performed, using Phobos 2 and Mars Global Surveyor, observations to determine the average location of the Martian bow shock and the magnetic pileup boundary (MPB). However, analysis of individual orbits shows that the location of these boundaries can be highly variable in response to the changing heliospheric environment, implying that an average boundary may not be as representative as finite thickness boundary layers. MAVEN has been in orbit and producing science observations since November 2014 providing a large number of orbits, approximately 5 per day, for the spacecraft to cross the induced boundaries during a wide range of heliospheric conditions. Using data from the Particle and Fields Package onboard the MAVEN spacecraft, we are able to determine the location and thickness of the bow shock and the MPB, during each orbit. Additionally, MAVEN's orbit precesses such that we observe boundary crossings over a wide range of latitude and longitudes, important if there is any influence on the variability of the boundaries from the Martian crustal fields. Here we present a new model for the boundaries of the Martian magnetosphere, with a finite thickness to capture the variability of their location due to the changing solar wind environment.

  19. Martian weather and climate in the 21st century

    SciTech Connect

    Zurek, R.W.

    1990-01-01

    The historical interest in the weather and climate of Mars and current understanding of aspects of the present climate are addressed. Scientific research into the weather and climate of Mars in the next century is examined. The impact of the Martian weather of the 21st century on humans that may then be inhabiting the planet is considered. 8 refs.

  20. Iron-montmorillonite - A spectral analog of Martian soil

    NASA Astrophysics Data System (ADS)

    Banin, A.; Margulies, L.; Chen, Y.

    1985-02-01

    Spectral data for smectite clays, particularly for montmorillonite, which contain various adsorbed ions and are measured in the UV, VIS, and NIR ranges are analyzed and compared with Martian soil and dust spectra. It is shown that the structural octahedral iron in smectite clays affects their light absorbance in the UV at 240-260 nm, which results from an O(2-) to Fe(3+) charge transfer, similar to one observed in the Martian spectrum. Adsorbed iron affects, via crystal field absorptions, the reflectance of montmorillonite in the VIS and NIR ranges, resulting in stronger absorption and higher opacity in the range 0.40-0.65 micron. Both in spectral contrast and presence of (or lack of) spectral features, the Fe-montmorillonite spectra in the VIS and NIR are in reasonable agreement with the Martian spectrum. It is found that the spectral characteristics of iron-saturated smectite clays cannot be used to preclude the presence of clays in Martian soils and dust.

  1. Samples from Martian craters: Origin of the Martian soil by hydrothermal alteration of impact melt deposits and atmospheric interactions with ejecta during crater formation

    NASA Technical Reports Server (NTRS)

    Newsom, Horton E.

    1988-01-01

    The origin of the Martian soil is an important question for understanding weathering processes on the Martian surface, and also for understanding the global geochemistry of Mars. Chemical analyses of the soil will provide an opportunity to examine what may be a crustal average, as studies of loess on the Earth have demonstrated. In this regard the origin of the Martian soil is also important for understanding the chemical fractionations that have affected the composition of the soil. Several processes that are likely to contribute to the Martian soil are examined.

  2. Synchrotron Characterization of Hydrogen and Ferric Iron in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Dyar, Melinda D.

    2003-01-01

    The hydrogen budget of the Martian interior is distributed among several phases: melts, hydrous minerals, and nominally anhydrous minerals like olivine, pyroxene, and garnet. All these phases are vulnerable to loss of hydrogen during shock, excavation and transport via the mechanism of dehydrogenation, in which the charge on the H protons is left behind as polarons on Fe atoms. Thus, both H and F(3x) must be analyzed in order to reconstruct hydrogen and oxygen fugacities on Mars. To date, SIMS data have elucidated D/H and H contents of hydrous phases in SNC meteorites, but anhydrous martian minerals have not been systematically examined for trace hydrogen. Ferric iron has been quantified using XANES in many marital phases, but integrated studies of both Fe(3x) and H on the same spots are really needed to address the H budget. Here, we measure and profile H and Fe(3x) abundances in and across individual grains of glass and silicates in Martian meteorites. We use the new technology of synchrotron microFI'lR spectroscopy to measure the hydrogen contents of hydrous and nominally anhydrous minerals in martian meteorites on 30-100 microns thick, doubly polished thin sections on spots down to 3 x 3 microns. Synchrotron microXANES was used to analyze Fe(3x) on the same scale, and complementary SIMS D/H data will be collected where possible, though at a slightly larger scale. Development of this combination of techniques is critical because future sample return missions will generate only microscopic samples for study. Results have been used to quantitatively assess the distribution of hydrogen and ferric iron among phases in the martian interior, which will better constrain the geodynamic processes of the interior, as well as the overall hydrogen and water budgets on Mars.

  3. Constraints on the Composition and Petrogenesis of the Martian Crust

    NASA Technical Reports Server (NTRS)

    McSween, Harry Y., Jr.; Grove, Timothy L.; Wyatt, Michael B.

    2003-01-01

    Spectral interpretation that silicic rocks are widespread on Mars implies that Earth's differentiated crust is not unique. Evaluation of observations bearing on the composition of the Martian crust (Martian meteorite petrology and a possible crustal assimilant, analysis of Mars Pathfinder rocks, composition of Martian fines, interpretation of spacecraft thermal emission spectra, and inferred crustal densities) indicates that the crust can be either basalt plus andesite or basalt plus weathering products. New calculated chemical compositions for Thermal Emission Spectrometer (TES) global surface units indicate that surface type 1 has basaltic andesite composition and surface type 2 has the composition of andesite. If these materials represent volcanic rocks, their calc-alkaline compositions on a FeO*/MgO versus silica diagram suggest formation by hydrous melting and fractional crystallization. On Earth, this petrogenesis requires subduction, and it may suggest an early period of plate tectonics on Mars. However, anorogenic production of andesite might have been possible if the primitive Martian mantle was wet. Alternatively, chemical weathering diagrams suggest that surface type 2 materials could have formed by partial weathering of surface type 1 rocks, leading to depletion in soluble cations and mobility of silica. A weathered crust model is consistent with the occurrence of surface type 2 materials as sediments in a depocenter and with the alpha proton X-ray spectrometer (APXS) analysis of excess oxygen suggesting weathering rinds on Pathfinder rocks. If surface type 1 materials are also weathered or mixed with weathered materials, this might eliminate the need for hydrous melting, consistent with a relatively dry Martian mantle without tectonics.

  4. Numerical simulation of the radiation environment on Martian surface

    NASA Astrophysics Data System (ADS)

    Zhao, L.

    2015-12-01

    The radiation environment on the Martian surface is significantly different from that on earth. Existing observation and studies reveal that the radiation environment on the Martian surface is highly variable regarding to both short- and long-term time scales. For example, its dose rate presents diurnal and seasonal variations associated with atmospheric pressure changes. Moreover, dose rate is also strongly influenced by the modulation from GCR flux. Numerical simulation and theoretical explanations are required to understand the mechanisms behind these features, and to predict the time variation of radiation environment on the Martian surface if aircraft is supposed to land on it in near future. The high energy galactic cosmic rays (GCRs) which are ubiquitous throughout the solar system are highly penetrating and extremely difficult to shield against beyond the Earth's protective atmosphere and magnetosphere. The goal of this article is to evaluate the long term radiation risk on the Martian surface. Therefore, we need to develop a realistic time-dependent GCR model, which will be integrated with Geant4 transport code subsequently to reproduce the observed variation of surface dose rate associated with the changing heliospheric conditions. In general, the propagation of cosmic rays in the interplanetary medium can be described by a Fokker-Planck equation (or Parker equation). In last decade,we witnessed a fast development of GCR transport models within the heliosphere based on accurate gas-dynamic and MHD backgrounds from global models of the heliosphere. The global MHD simulation produces a more realistic pattern of the 3-D heliospheric structure, as well as the interface between the solar system and the surrounding interstellar space. As a consequence, integrating plasma background obtained from global-dependent 3-D MHD simulation and stochastic Parker transport simulation, we expect to produce an accurate global physical-based GCR modulation model. Combined

  5. Spectral characterization of acid weathering products on Martian basaltic glass

    NASA Astrophysics Data System (ADS)

    Yant, Marcella; Rogers, A. Deanne; Nekvasil, Hanna; Zhao, Yu-Yan Sara; Bristow, Tom

    2016-03-01

    For the first time, direct infrared spectral analyses of glasses with Martian compositions, altered under controlled conditions, are presented in order to assess surface weathering and regolith development on Mars. Basaltic glasses of Irvine and Backstay composition were synthesized and altered using H2SO4-HCl acid solutions (pH 0-4). Scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, Raman, and infrared spectral measurements were acquired for each reaction product. Infrared spectra were also acquired from previously synthesized and altered glasses with Pathfinder-measured compositions. Acid alteration on particles in the most acidic solutions (pH ≤ 1) yielded sulfate-dominated visible near infrared (VNIR) and thermal infrared (TIR) spectra with some silica influence. Spectral differences between alteration products from each starting material were present, reflecting strong sensitivity to changes in mineral assemblage. In the TIR, alteration features were preserved after reworking and consolidation. In the VNIR, hydrated sulfate features were present along with strong negative spectral slopes. Although such signatures are found in a few isolated locations on Mars with high-resolution spectrometers, much of the Martian surface lacks these characteristics, suggesting the following: acid alteration occurred at pH ≥ 2; small amounts of sulfates were reworked with unaltered material; there is a prevalence of intermediate-to-high silica glass in Martian starting materials (more resistant to acid alteration); primary or added sulfur were lacking; alteration features are obscured by dust; and/or large-scale, pervasive, acid sulfate weathering of the Martian surface did not occur. These results highlight the need to better understand the spectral properties of altered Martian surface material in order to enhance the interpretation of remote spectra for altered terrains.

  6. Infrared radiative transfer in the dust-free Martian atmosphere

    SciTech Connect

    Crisp, D. )

    1990-08-30

    Gases in the Martian atmosphere, including CO{sub 2}, H{sub 2}O, CO, and O{sub 3}, combine to produce some absorption at most infrared wavelengths. Line-by-line and quasi-random models are used to derive synthetic spectra of dust-free Martian atmospheres. These spectra show where gases absorb most strongly and provide a baseline for comparison with the results from more complete models that include the effects of dust. Gas absorption and emission features at many infrared wavelengths provide a source of contamination that must be removed from remote sensing observations of the Martian surface. For example, the weak reflectance minimum observed at wavelengths near 2.35 {mu}m, which has been interpreted as evidence for a variety of surface materials, is produced almost entirely by atmospheric CO and CO{sub 2} absorption. Isotopic CO{sub 2} bands near 7 and 8 {mu}m and near-infrared water vapor absorption bands partially overlap strong carbonate and hydrate features and frustrate systematic spectroscopic searches for these important candidate surface materials on Mars. In other spectral regions, gas absorption bands provide opportunities to study the structure and composition of the Martian atmosphere. Computed radiances within the strong CO{sub 2} 15-{mu}m band are incorporated into an atmospheric retrieval algorithm to derive the atmospheric temperature structure from Mariner 9 IRIS observations. Absorption and emission by gases also contributes to the energetics of the Martian atmosphere. Near-infrared CO{sub 2} bands absorb enough sunlight to produce globally-averaged solar heating rates that vary from 1 K/Earth day at the surface, to 10 K/Earth day at pressures near 0.01 mbar. Other gases contribute 1-5% of the heating at some levels.

  7. Planetary Bioresources and Astroecology. 1. Planetary Microcosm Bioassays of Martian and Carbonaceous Chondrite Materials: Nutrients, Electrolyte Solutions, and Algal and Plant Responses

    NASA Astrophysics Data System (ADS)

    Mautner, Michael N.

    2002-07-01

    The biological fertilities of planetary materials can be assessed using microcosms based on meteorites. This study applies microcosm tests to martian meteorites and analogues and to carbonaceous chondrites. The biological fertilities of these materials are rated based on the soluble electrolyte nutrients, the growth of mesophile and cold-tolerant algae, and plant tissue cultures. The results show that the meteorites, in particular the Murchison CM2 carbonaceous chondrite and DaG 476 martian shergottite, contain high levels of water-extractable Ca, Mg, and SO 4-S. The martian meteorites DaG 476 and EETA 79001 also contain higher levels of extractable essential nutrients NO 3-N (0.013-0.017 g kg -1) and PO 4-P (0.019-0.046 g kg -1) than the terrestrial analogues. The yields of most of the water-extractable electrolytes vary only by factors of 2-3 under a wide range of planetary conditions. However, the long-term extractable phosphate increases significantly under a CO 2 atmosphere. The biological yields of algae and plant tissue cultures correlate with extractable NO 3-N and PO 4-P, identifying these as the limiting nutrients. Mesophilic algae and Asparagus officinalis cultures are identified as useful bioassay agents. A fertility rating system based on microcosm tests is proposed. The results rate the fertilities in the order martian basalts > terrestrial basalt, agricultural soil > carbonaceous chondrites, lava ash > cumulate igneous rock. The results demonstrate the application of planetary microcosms in experimental astroecology to rate planetary materials as targets for astrobiology exploration and as potential space bioresources. For example, the extractable materials in Murchison suggest that concentrated internal solutions in carbonaceous asteroids (3.8 mol L -1 electrolytes and 10 g L -1 organics) can support and disperse microorganisms introduced by natural or directed panspermia in early solar systems. The results also suggest that carbonaceous asteroids

  8. Durham, North Carolina, Students Study Martian Volcanism

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image of the wall of a graben a depressed block of land between two parellel faults in Tyrrhena Terra, in Mars' ancient southern highlands, was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 0914 UTC (4:14 a.m. EST) on February 6, 2008, near 17.3 degrees south latitude, 95.5 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 35 meters (115 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point.

    This image was part of an investigation planned by students in four high schools in Durham, North Carolina. The students are working with the CRISM science team in a project called the Mars Exploration Student Data Teams (MESDT), which is part of NASA's Mars Public Engagement Program and Arizona State University's Mars Education Program. Starting with a medium-resolution map of the area, taken as part of CRISM's 'multispectral survey' campaign to map Mars in 72 colors at 200 meters (660 feet) per pixel, the students identified a key rock outcrop to test their hypothesis that the irregular depression was formed by Martian volcanism. They provided the coordinates of the target to CRISM's operations team, who took a high-resolution image of the site. The Context Imager (CTX) accompanied CRISM with a 6 meter (20 feet) per pixel, high-resolution image to sharpen the relationship of spectral variations to the underlying surface structures. The Durham students worked with a mentor on the CRISM team to analyze the data, and presented their results at the 39th Lunar and Planetary Science Conference, held in League City, Texas, on March 10-14, 2008.

    The upper panel of the image shows the location of the CRISM data and the surrounding, larger CTX image, overlain on an image mosaic taken by the Thermal Emission Imaging System (THEMIS) on Mars Odyssey. The mosaic has been color-coded for elevation using data from the Mars

  9. The Martian Prime Meridian -- Longitude 'Zero'

    NASA Technical Reports Server (NTRS)

    2001-01-01

    , 746A46), and these two images were the basis of the martian longitude system for the rest of the 20th Century.

    The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) has attempted to take a picture of Airy-0 on every close overflight since the beginning of the MGS mapping mission. It is a measure of the difficulty of hitting such a small target that nine attempts were required, since the spacecraft did not pass directly over Airy-0 until almost the end of the MGS primary mission, on orbit 8280 (January 13, 2001).

    In the left figure above, the outlines of the Mariner 9, Viking, and Mars Global Surveyor images are shown on a MOC wide angle context image, M23-00924. In the right figure, sections of each of the three images showing the crater Airy-0 are presented. A is a piece of the Mariner 9 image, B is from the Viking image, and C is from the MGS image. Airy-0 is the larger crater toward the top-center in each frame.

    The MOC observations of Airy-0 not only provide a detailed geological close-up of this historic reference feature, they will be used to improve our knowledge of the locations of all features on Mars, which will in turn enable more precise landings on the Red Planet by future spacecraft and explorers.

  10. Sunscreening Agents

    PubMed Central

    Martis, Jacintha; Shobha, V; Sham Shinde, Rutuja; Bangera, Sudhakar; Krishnankutty, Binny; Bellary, Shantala; Varughese, Sunoj; Rao, Prabhakar; Naveen Kumar, B.R.

    2013-01-01

    The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food and Drug Administration and European Union have incorporated changes in their guidelines to help consumers select products based on their sun protection factor and protection against ultraviolet radiation, whereas the Indian regulatory agency has not yet issued any special guidance on sunscreening agents, as they are classified under cosmetics. In this article, the authors discuss the pharmacological actions of sunscreening agents as well as the available formulations, their benefits, possible health hazards, safety, challenges, and proper application technique. New technologies and scope for the development of sunscreening agents are also discussed as well as the role of the physician in patient education about the use of these agents. PMID:23320122

  11. Light Lithophile Elements in Natural and Experimental Phases in Martian Basalts: Implications for the Degassing of Water from Martian Magmas

    NASA Technical Reports Server (NTRS)

    Herd, C. D. K.; Treiman, A. H.; McKay, G. A.; Shearer, C. K.

    2003-01-01

    Lentz et al. argued that zoning trends in light lithophile elements (LLE) in pyroxene in Shergotty and Zagami are evidence for the degassing of magmatic water. We tested this inference by obtaining: additional LLE analyses of Shergotty and Zagami pyroxene; analyses of Pasamonte pyroxene; and silicate and phosphate partition coefficients for B and Li for martian magma and mineral compositions.

  12. Insights into the Martian Regolith from Martian Meteorite Northwest Africa 7034

    NASA Technical Reports Server (NTRS)

    McCubbin, Francis M.; Boyce, Jeremy W.; Szabo, Timea; Santos, Alison R.; Domokos, Gabor; Vazquez, Jorge; Moser, Desmond E.; Jerolmack, Douglas J.; Keller, Lindsay P.; Tartese, Romain

    2015-01-01

    Everything we know about sedimentary processes on Mars is gleaned from remote sensing observations. Here we report insights from meteorite Northwest Africa (NWA) 7034, which is a water-rich martian regolith breccia that hosts both igneous and sedimentary clasts. The sedimentary clasts in NWA 7034 are poorly-sorted clastic siltstones that we refer to as protobreccia clasts. These protobreccia clasts record aqueous alteration process that occurred prior to breccia formation. The aqueous alteration appears to have occurred at relatively low Eh, high pH conditions based on the co-precipitation of pyrite and magnetite, and the concomitant loss of SiO2 from the system. To determine the origin of the NWA 7034 breccia, we examined the textures and grain-shape characteristics of NWA 7034 clasts. The shapes of the clasts are consistent with rock fragmentation in the absence of transport. Coupled with the clast size distribution, we interpret the protolith of NWA 7034 to have been deposited by atmospheric rainout resulting from pyroclastic eruptions and/or asteroid impacts. Cross-cutting and inclusion relationships and U-Pb data from zircon, baddelleyite, and apatite indicate NWA 7034 lithification occurred at 1.4-1.5 Ga, during a short-lived hydrothermal event at 600-700 C that was texturally imprinted upon the submicron groundmass. The hydrothermal event caused Pb-loss from apatite and U-rich metamict zircons, and it caused partial transformation of pyrite to submicron mixtures of magnetite and maghemite, indicating the fluid had higher Eh than the fluid that caused pyrite-magnetite precipitation in the protobreccia clasts. NWA 7034 also hosts ancient 4.4 Ga crustal materials in the form of baddelleyites and zircons, providing up to a 2.9 Ga record of martian geologic history. This work demonstrates the incredible value of sedimentary basins as scientific targets for Mars sample return missions, but it also highlights the importance of targeting samples that have not been

  13. The Martian paleo-magnetosphere during the early Naochian and its implication for the early Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Khodachenko, Maxim L.; Scherf, Manuel; Amerstorfer, Ute; Alexeev, Igor; Johnstone, Colin; Belenkaya, Elena; Tu, Lin; Lichtenegger, Herbert; Guedel, Manuel; Lammer, Helmut

    2016-10-01

    During the late 1990's the Mars Global Surveyor MAG/ER experiment detected crustal remanent magnetization at Mars indicating an ancient internal magnetic dynamo. The location of this remanent magnetization and in particular its absence at the large Martian impact craters like Hellas suggests a cessation of the dynamo during the early Naochian epoch, i.e. ~ 4.1 to 4 billion years ago. The strength of the remanent magnetization together with dynamo theory are indicating an ancient dipole field strength lying in the range of ~0.1 and ~1.0 of the present-day dipole field of the Earth, making the Martian paleo-magnetosphere comparable with the terrestrial paleo-magnetosphere. This also has implication for the early Martian atmosphere.In this poster we will present simulations of the paleo-magnetosphere of Mars for the early Naochian, just before cessation (i.e. for ~4.1 to ~4.0 billion years ago). These were performed with an adapted version of the Paraboloid Magnetospheric Model (PMM) of the Skobeltsyn Institute of Nuclear Physics of the Moscow State University, which serves as an ISO standard for the magnetosphere. Here the ancient magnetic field was assumed to be a dipole field (with dipole tilt ψ=0). The ancient solar wind ram pressure as important input parameter was derived from a newly developed solar/stellar wind evolution model, which is strongly dependent on the rotation rate of the early Sun. These simulations show that for the most extreme case of a fast rotating Sun and a paleomagnetic field strength of 0.1 of the present-day Earth value, the Martian magnetopause was located at ~5.5 RM (i.e. ~2.9 RE) above the Martian surface. Assuming a strong dipole field (i.e. 1.0 of present-day Earth) and a slow rotating Sun – our least extreme case - would lead to a standoff-distance of rs~16 RM (i.e. ~8.5 RE).Our simulations also have implications for the early Martian atmosphere, which will be demonstrated within this poster. These first results on the erosion of

  14. Laboratory Shock Experiments on Basalt - Iron Sulfate Mixes at ~ 40 - 50 GPa and their Relevance to the Martian Reolith Component Present in Shergotties

    SciTech Connect

    Rao, M N; Nyquist, L E; Ross, D K; Asimow, P D; See, T; Sutton, S; Cardernas, F; Montes, R; Cintala, M

    2012-03-14

    Basaltic shergottites such as Shergotty, Zagami and EET79001 contain impact melt glass pockets that are rich in Martian atmospheric gases and are known as gas-rich impact-melt (GRIM) glasses. These glasses show evidence for the presence of a Martian regolith component based on Sm and Kr isotopic studies. The GRIM glasses are sometimes embedded with clusters of innumerable micron-sized iron-sulfide blebs associated with minor amounts of iron sulfate particles. These sulfide blebs are secondary in origin and are not related to the primary igneous sulfides occurring in Martian meteorites. The material comprising these glasses arises from the highly oxidizing Martian surface and sulfur is unlikely to occur as sulfide in the Martian regoilith. Instead, sulfur is shown to occur as sulfate based on APXS and Mossbauer results obtained by the Opportunity and Spirit rovers at Meridiani and Gusev. We have earlier suggested that the micron-sized iron sulfide globules in GRIM glasses were likely produced by shock-reduction of iron sulfate occurring in the regolith at the time when the GRIM glasses were produced by the meteoroid impact that launched the Martian meteorites into space. As a result of high energy deposition by shock (~ 40-60 GPa), the iron sulfate bearing phases are likely to melt along with other regolith components and will get reduced to immiscible sulfide fluid under reducing conditions. On quenching, this generates a dispersion of micron-scale sulfide blebs. The reducing agents in our case are likely to be H2 and CO which were shock-implanted from the Martian atmosphere into these glasses along with the noble gases. We conducted lab simulation experiments in the Lindhurst Laboratory of Experimental Geophysics at Caltech and the Experimental Impact Laboratory at JSC to test whether iron sulfide globules can be produced by impact-driven reduction of iron sulfate by subjecting Columbia River Basalt (CRB) and ferric sulfate mixtures to shock pressures

  15. Laboratory Shock Experiments on Basalt - Iron Sulfate Mixes at Approximately 40-50 GPa and Their Relevance to the Martian Regolith Component Present in Shergottites

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Nyquist, L. E.; Ross, D. K.; Asimow, P. D.; See, T.; Sutton, S.; Cardernas, F.; Montes, R.; Cintala, M.

    2012-01-01

    Basaltic shergottites such as Shergotty, Zagami and EET79001 contain impact melt glass pockets that are rich in Martian atmospheric gases [1] and are known as gas-rich impact-melt (GRIM) glasses. These glasses show evidence for the presence of a Martian regolith component based on Sm and Kr isotopic studies [2]. The GRIM glasses are sometimes embedded with clusters of innumerable micron-sized iron-sulfide blebs associated with minor amounts of iron sulfate particles [3, 4]. These sulfide blebs are secondary in origin and are not related to the primary igneous sulfides occurring in Martian meteorites. The material comprising these glasses arises from the highly oxidizing Martian surface and sulfur is unlikely to occur as sulfide in the Martian regoilith. Instead, sulfur is shown to occur as sulfate based on APXS and Mossbauer results obtained by the Opportunity and Spirit rovers at Meridiani and Gusev [5]. We have earlier suggested that the micron-sized iron sulfide globules in GRIM glasses were likely produced by shock-reduction of iron sulfate occurring in the regolith at the time when the GRIM glasses were produced by the meteoroid impact that launched the Martian meteorites into space [6]. As a result of high energy deposition by shock (approx. 40-60 GPa), the iron sulfate bearing phases are likely to melt along with other regolith components and will get reduced to immiscible sulfide fluid under reducing conditions. On quenching, this generates a dispersion of micron-scale sulfide blebs. The reducing agents in our case are likely to be H2 and CO which were shock-implanted from the Martian atmosphere into these glasses along with the noble gases. We conducted lab simulation experiments in the Lindhurst Laboratory of Experimental Geophysics at Caltech and the Experimental Impact Laboratory at JSC to test whether iron sulfide globules can be produced by impact-driven reduction of iron sulfate by subjecting Columbia River Basalt (CRB) and ferric sulfate mixtures to

  16. Antiparasitic agents.

    PubMed

    Rosenblatt, J E

    1992-03-01

    In recent years, introduction of new and more effective agents has improved the overall therapy for parasitic infections. This field, however, is still plagued by numerous problems, including the development of resistance to antimicrobial agents (especially with malaria), unavailability of agents in the United States or lack of approval by the Food and Drug Administration, and major toxicities or lack of experience in pregnant women and children, which limits use in these groups of patients. Widespread resistance of Plasmodium falciparum to chloroquine and other agents has complicated the treatment and prophylaxis of this type of malaria. A combination of quinine and Fansidar is usually effective oral therapy for falciparum malaria; quinidine may be administered if intravenous therapy is needed. Mefloquine, which is currently recommended for prophylaxis against chloroquine-resistant P. falciparum, is also effective for single-dose oral treatment, although this regimen has not yet been approved by the Food and Drug Administration. Metronidazole has been widely used for treatment of gastroenteritis due to Entamoeba histolytica and Giardia lamblia (not approved by the Food and Drug Administration for the latter) and is considered safe and effective. A new macrolide, azithromycin, has been reported to be effective for cryptosporidiosis in experimental animals; currently, no effective therapy is available for human infections. Combinations of sulfonamides with other antifolates, trimethoprim or pyrimethamine, are recommended therapy for Pneumocystis carinii pneumonia or toxoplasmosis, respectively. Therapies for the various types of leishmaniasis and trypanosomiasis are complex, often toxic, and often of limited efficacy. The benzimidazoles are effective for roundworm infections, although thiabendazole has severe toxic effects. The recent introduction of ivermectin has revolutionized the treatment and control of onchocerciasis. Another relatively new agent, praziquantel

  17. Evolution of the martian mantle as recorded by igneous rocks

    NASA Astrophysics Data System (ADS)

    Balta, J. B.; McSween, H. Y.

    2013-12-01

    Martian igneous rocks provide our best window into the current state of the martian mantle and its evolution after accretion and differentiation. Currently, those rocks have been examined in situ by rovers, characterized in general from orbiting spacecraft, and analyzed in terrestrial laboratories when found as meteorites. However, these data have the potential to bias our understanding of martian magmatism, as most of the available meteorites and rover-analyzed rocks come from the Amazonian (<2 Ga) and Hesperian (~3.65 Ga) periods respectively, while igneous rocks from the Noachian (>3.8 Ga) have only been examined by orbiters and as the unique meteorite ALH 84001. After initial differentiation, the main planetary-scale changes in the structure of Mars which impact igneous compositions are cooling of the planet and thickening of the crust with time. As the shergottite meteorites give ages <500 Ma1, they might be expected to represent thick-crust, recent volcanism. Using spacecraft measurements of volcanic compositions and whole rock compositions of meteorites, we demonstrate that the shergottite meteorites do not match the composition of the igneous rocks composing the young volcanoes on Mars, particularly in their silica content, and no crystallization or crustal contamination trend reproduces the volcanoes from a shergottite-like parent magma. However, we show that the shergottite magmas do resemble older martian rocks in composition and mineralogy. The Noachian-aged meteorite ALH 84001 has similar radiogenic-element signatures to the shergottites and may derive from a similar mantle source despite the age difference2. Thus, shergottite-like magmas may represent melting of mantle sources that were much more abundant early in martian history. We propose that the shergottites represent the melting products of an originally-hydrous martian mantle, containing at least several hundred ppm H2O. Dissolved water can increase the silica content of magmas and thus

  18. Laboratory experiments to explore the sediment transport capacity of carbon dioxide sublimation under martian conditions

    NASA Astrophysics Data System (ADS)

    Sylvest, Matthew; Conway, Susan; Patel, Manish; Dixon, John; Barnes, Adam

    2015-04-01

    Every spring, the solid carbon dioxide deposited over the martian high latitudes sublimates. Several, unusual surface features, including dark spots and flows on sand dunes, as well as recent activity in martian gullies, have been associated with this CO2 sublimation. Water and/or brines have also been proposed as potential agents for these events, but the timing of these phenomena suggest CO2 sublimation is more likely. However, the exact mechanism by which CO2 sublimation moves sediment is not fully understood, and this understanding is required to validate the CO2 hypothesis. Here we present the results of the first ever laboratory simulations of this process under martian conditions, and show that significant quantities of loose sediment can be transported. The centrepiece of the apparatus is a 1m diameter, 2m long Mars simulation chamber, housed at The Open University, UK. JSC Mars-1A regolith simulant was formed into a slope, inside a box, ~30 cm long, 23 cm wide by 12 cm deep. The box is constructed of coiled, copper tubing to allow cooling of the regolith by liquid nitrogen. The experimental procedure consists of four stages: 1) establishment of a dry atmosphere in the chamber, 2) cooling the regolith sufficiently to support condensation of CO2 frost at reduced pressure, 3) introduction of cooled CO2 gas above the regolith to deposit as frost, and 4) video recording the surface evolution under radiant heating (~100 mins). Two High Definition digital video cameras were mounted above the box and image pairs taken from the videos were then used to create digital elevation models (DEMs) in Agisoft Photoscan at regular intervals. In our initial experiments we performed four experimental runs where the slope was set at or near the angle of repose (~30°). In each case we observed mass wasting events triggered by the sublimation of the deposited CO2 over the whole duration of the insolation. The highest levels of activity occurred in the first third of the run

  19. Terrestrial microbes in martian and chondritic meteorites

    NASA Astrophysics Data System (ADS)

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

    2007-08-01

    Introduction: The best extraterrestrial analogs for microbiology are meteorites. The chemistry and mineralogy of Asteroid Belt and martian (SNC) meteorites are used as tracers of processes that took place in the early solar system. Meteoritic falls, in particular those of carbonaceous chondrites, are regarded as pristine samples of planetesimal evolution as these rocks are primitive and mostly unprocessed since the formation of the solar system 4.56 billion years ago. Yet, questions about terrestrial contamination and its effects on the meteoritic isotopic, chemical and mineral characteristics often arise. Meteorites are hosts to biological activity as soon as they are in contact with the terrestrial biosphere, like all rocks. A wide biodiversity was found in 21 chondrites and 8 martian stones, and was investigated with cell culture, microscopy techniques, PCR, and LAL photoluminetry. Some preliminary results are presented here. The sample suite included carbonaceous chondrites of types CR, CV, CK, CO, CI, and CM, from ANSMET and Falls. Past studies documented the alteration of meteorites by weathering and biological activity [1]-[4]. Unpublished observations during aqueous extraction for oxygen isotopic analysis [5], noted the formation of biofilms in water in a matter of days. In order to address the potential modification of meteoritic isotopic and chemical signatures, the culture of microbial contaminating species was initiated in 2005, and after a prolonged incubation, some of the species obtained from cell culture were analyzed in 2006. The results are preliminary, and a systematic catalog of microbial contaminants is developing very slowly due to lack of funding. Methods: The primary method was cell culture and PCR. Chondrites. Chondritic meteorite fragments were obtained by breaking stones of approximately one gram in sterile mortars. The core of the rocks, presumably less contaminated than the surface, was used for the present microbial study, and the

  20. Antidiabetic Agents.

    ERIC Educational Resources Information Center

    Plummer, Nancy; Michael, Nancy, Ed.

    This module on antidiabetic agents is intended for use in inservice or continuing education programs for persons who administer medications in long-term care facilities. Instructor information, including teaching suggestions, and a listing of recommended audiovisual materials and their sources appear first. The module goal and objectives are then…

  1. Mitigating Adverse Effects of a Human Mission on Possible Martian Indigenous Ecosystems

    NASA Astrophysics Data System (ADS)

    Lupisella, M. L.

    2000-07-01

    Although human beings are, by most standards, the most capable agents to search for and detect extraterrestrial life, we are also potentially the most harmful. While there has been substantial work regarding forward contamination with respect to robotic missions, the issue of potential adverse effects on possible indigenous Martian ecosystems, such as biological contamination, due to a human mission has remained relatively unexplored and may require our attention now as this presentation will try to demonstrate by exploring some of the relevant scientific questions, mission planning challenges, and policy issues. An informal, high-level mission planning decision tree will be discussed and is included as the next page of this abstract. Some of the questions to be considered are: (1) To what extent could contamination due to a human presence compromise possible indigenous life forms? (2) To what extent can we control contamination? For example, will it be local or global? (3) What are the criteria for assessing the biological status of Mars, both regionally and globally? For example, can we adequately extrapolate from a few strategic missions such as sample return missions? (4) What should our policies be regarding our mission planning and possible interaction with what are likely to be microbial forms of extraterrestrial life? (5) Central to the science and mission planning issues is the role and applicability of terrestrial analogs, such as Lake Vostok for assessing drilling issues, and modeling techniques. Central to many of the policy aspects are scientific value, international law, public concern, and ethics. Exploring this overall issue responsibly requires an examination of all these aspects and how they interrelate. A chart is included, titled 'Mission Planning Decision Tree for Mitigating Adverse Effects to Possible Indigenous Martian Ecosystems due to a Human Mission'. It outlines what questions scientists should ask and answer before sending humans to Mars.

  2. Mitigating Adverse Effects of a Human Mission on Possible Martian Indigenous Ecosystems

    NASA Technical Reports Server (NTRS)

    Lupisella, M. L.

    2000-01-01

    Although human beings are, by most standards, the most capable agents to search for and detect extraterrestrial life, we are also potentially the most harmful. While there has been substantial work regarding forward contamination with respect to robotic missions, the issue of potential adverse effects on possible indigenous Martian ecosystems, such as biological contamination, due to a human mission has remained relatively unexplored and may require our attention now as this presentation will try to demonstrate by exploring some of the relevant scientific questions, mission planning challenges, and policy issues. An informal, high-level mission planning decision tree will be discussed and is included as the next page of this abstract. Some of the questions to be considered are: (1) To what extent could contamination due to a human presence compromise possible indigenous life forms? (2) To what extent can we control contamination? For example, will it be local or global? (3) What are the criteria for assessing the biological status of Mars, both regionally and globally? For example, can we adequately extrapolate from a few strategic missions such as sample return missions? (4) What should our policies be regarding our mission planning and possible interaction with what are likely to be microbial forms of extraterrestrial life? (5) Central to the science and mission planning issues is the role and applicability of terrestrial analogs, such as Lake Vostok for assessing drilling issues, and modeling techniques. Central to many of the policy aspects are scientific value, international law, public concern, and ethics. Exploring this overall issue responsibly requires an examination of all these aspects and how they interrelate. A chart is included, titled 'Mission Planning Decision Tree for Mitigating Adverse Effects to Possible Indigenous Martian Ecosystems due to a Human Mission'. It outlines what questions scientists should ask and answer before sending humans to Mars.

  3. Modeling Cooling Rates of Martian Flood Basalt Columns

    NASA Astrophysics Data System (ADS)

    Weiss, D. K.; Jackson, B.; Milazzo, M. P.; Barnes, J. W.

    2011-12-01

    Columnar jointing in large basalt flows have been extensively studied and can provide important clues about the emplacement conditions and cooling history of a basalt flow. The recent discovery of basalt columns on Mars in crater walls near Marte Vallis provides an opportunity to infer conditions on early Mars when the Martian basalt flows were laid down. Comparison of the Martian columns to Earth analogs allows us to gain further insight into the early Martian climate, and among the best terrestrial analogs are the basalt columns in the Columbia River Basalt Group (CRBG) in eastern Washington. The CRBG is one of the youngest (< 17 Myrs old) and most extensively studied basalt provinces in the world, extending over 163,700 square km with total thickness exceeding 1 km in some places. The morphologies and textures of CRBG basalt columns suggest that in many places flows ~100 m thick cooled at uniform rates, even deep in the flow interior. Such cooling seems to require the presence of water in the column joints since the flow interiors should have cooled much more slowly than the flow margins if conductive cooling dominated. Secondary features, such pillow basalts, likewise suggest the basalt flows were in direct contact with standing water in many places. At the resolution provided by the orbiting HiRISE camera (0.9 m), the Martian basalt columns resemble the CRBG columns in many respects, and so, subject to important caveats, inferences linking the morphologies of the CRBG columns to their thermal histories can be extended in some respects to the Martian columns. In this presentation, we will describe our analysis of the HiRISE images of the Martian columns and what can be reasonably inferred about their thermal histories and the conditions under which they were emplaced. We will also report on a field expedition to the CRBG in eastern Washington State. During that expedition, we surveyed basalt column outcrops on the ground and from the air using Unmanned Aerial

  4. Harmonic Analysis of Zonal Density Structures in Martian Upper Atmosphere

    NASA Astrophysics Data System (ADS)

    Withers, P.; Bougher, S. W.; Keating, G. M.

    2001-05-01

    Mars Global Surveyor Accelerometer measurements of density in the martian upper atmosphere during aerobraking are now available via the PDS [Keating et al, 2001]. We are continuing our investigations of variations in density with longitude at fixed local solar time, latitude, and season, concentrating on Phase 2 of aerobraking. We find that, contrary to previous suspicions, the zonal structure is not dominated solely by wave-2 harmonics. The dominant harmonics are as follows: wave-3 in the northern extratropics, wave-2 and wave-3 in the tropics, and no clearly dominant harmonic in the southern extratropics. The relative amplitudes of the various harmonics vary with latitude. However, their phases remain very stable, despite large changes in the phasing of the corresponding harmonic of zonal topography. Relative to the mean density, the amplitudes of the various harmonics decrease as altitude increases. This is opposite to the behaviour predicted by a simple, dissipation-less model of the martian upper atmosphere, in which deviations from the background state of the atmosphere are proportional to the inverse of the square root of pressure, and indicates the presence of damping in the upper atmosphere. When the martian day was an integer multiple of the spacecraft orbital period, the accelerometer measured densities at the same latitude, local solar time, season, and longitude each martian day. This period of resonance lasted for several days as the spacecraft orbital period decreased through the critical value due to drag. This permits us to examine the true variability of the martian upper atmosphere without the complications of the zonal variability. An accurate estimate of this essentially unpredictable variability is crucial for effective and efficient aerobraking of future spacecraft missions. At an altitude of 130 km, variabilities of 15 percent were typical, though values of 30 percent were observed. This variability also decreased as altitude increased, an

  5. S.A.M., the Italian Martian simulation chamber.

    PubMed

    Galletta, G; Ferri, F; Fanti, G; D'Alessandro, M; Bertoloni, G; Pavarin, D; Bettanini, C; Cozza, P; Pretto, P; Bianchini, G; Debei, S

    2006-12-01

    The Martian Environment Simulator (SAM "Simulatore di Ambiente Marziano") is a interdisciplinary project of Astrobiology done at University of Padua. The research is aimed to the study of the survival of the microorganisms exposed to the "extreme" planetary environment. The facility has been designed in order to simulate Mars' environmental conditions in terms of atmospheric pressure, temperature cycles and UV radiation dose. The bacterial cells, contained into dedicated capsules, will be exposed to thermal cycles simulating diurnal and seasonal Martian cycles. The metabolism of the different biological samples will be analysed at different phases of the experiment, to study their survival and eventual activity of protein synthesis (mortality, mutations and capability of DNA repairing). We describe the experimental facility and provide the perspectives of the biological experiments we will perform in order to provide hints on the possibility of life on Mars either autochthonous or imported from Earth.

  6. The application of NERVA technology to Martian power plants

    NASA Astrophysics Data System (ADS)

    Farbman, G. H.; Pierce, B. L.

    1991-09-01

    A Martian Nuclear Power Plant is described, based on the nuclear technologies developed and demonstrated in the NERVA nuclear propulsion program. The reactor is in a closed-cycle system, employing an inert gas coolant, while the power-turbine generator system is an open-cycle gas turbine which uses the Martian atmosphere as a working fluid. The two systems are connected by a double-walled heat exchanger which transfers energy from the reactor to the power turbine system. The plant is rated at 3 MWe and is capable of three years of power operation, at a capacity factor of 90 percent, before the fuel is depleted. The plant is arranged in modules, which are fully constructed on earth and then interconnected on the surface of Mars. A preliminary estimate of the module contents and masses leads to a total plant specific mass of 25.3 kg/kWe.

  7. Numerical Model Studies of the Martian Mesoscale Circulations

    NASA Technical Reports Server (NTRS)

    Segal, M.; Arritt, R. W.

    1996-01-01

    Studies concerning mesoscale topographical effects on Martian flows examined low-level jets in the near equatorial latitudes and the dynamical intensification of flow by steep terrain. Continuation of work from previous years included evaluating the dissipation of cold air mass outbreaks due to enhanced sensible heat flux, further sensitivity and scaling evaluations for generalization of the characteristics of Martian mesoscale circulation caused by horizontal sensible heat-flux gradients, and evaluations of the significance that non-uniform surface would have on enhancing the polar CO2 ice sublimation during the spring. The sensitivity of maximum and minimum atmospheric temperatures to changes in wind speed, surface albedo, and deep soil temperature was investigated.

  8. Filter Media Tests Under Simulated Martian Atmospheric Conditions

    NASA Technical Reports Server (NTRS)

    Agui, Juan H.

    2016-01-01

    Human exploration of Mars will require the optimal utilization of planetary resources. One of its abundant resources is the Martian atmosphere that can be harvested through filtration and chemical processes that purify and separate it into its gaseous and elemental constituents. Effective filtration needs to be part of the suite of resource utilization technologies. A unique testing platform is being used which provides the relevant operational and instrumental capabilities to test articles under the proper simulated Martian conditions. A series of tests were conducted to assess the performance of filter media. Light sheet imaging of the particle flow provided a means of detecting and quantifying particle concentrations to determine capturing efficiencies. The media's efficiency was also evaluated by gravimetric means through a by-layer filter media configuration. These tests will help to establish techniques and methods for measuring capturing efficiency and arrestance of conventional fibrous filter media. This paper will describe initial test results on different filter media.

  9. The age of the carbonates in martian meteorite ALH84001.

    PubMed

    Borg, L E; Connelly, J N; Nyquist, L E; Shih, C Y; Wiesmann, H; Reese, Y

    1999-10-01

    The age of secondary carbonate mineralization in the martian meteorite ALH84001 was determined to be 3.90 +/- 0.04 billion years by rubidium-strontium (Rb-Sr) dating and 4.04 +/- 0.10 billion years by lead-lead (Pb-Pb) dating. The Rb-Sr and Pb-Pb isochrons are defined by leachates of a mixture of high-graded carbonate (visually estimated as approximately 5 percent), whitlockite (trace), and orthopyroxene (approximately 95 percent). The carbonate formation age is contemporaneous with a period in martian history when the surface is thought to have had flowing water, but also was undergoing heavy bombardment by meteorites. Therefore, this age does not distinguish between aqueous and impact origins for the carbonates. PMID:10506566

  10. Orbital evolution and origin of the Martian satellites

    SciTech Connect

    Szeto, A.M.K.

    1983-07-01

    The orbital evolution of the Martian satellites is considered from a dynamical point of view. Celestial mechanics relevant to the calculation of satellite orbital evolution is introduced and the physical parameters to be incorporated in the modeling of tidal dissipation are discussed. Results of extrapolating the satellite orbits backward and forward in time are presented and compared with those of other published work. Collision probability calculations and results for the Martian satellite system are presented and discussed. The implications of these calculations for the origin scenarios of the satellites are assessed. It is concluded that Deimos in its present form could not have been captured, for if it had been, it would have collided with Phobos at some point. An accretion model is therefore preferred over capture, although such a model consistent with the likely carbonaceous chondritic composition of the satellites has yet to be established. 91 references.

  11. Chemistry and mineralogy of Martian dust: An explorer's primer

    NASA Technical Reports Server (NTRS)

    Gooding, James L.

    1991-01-01

    A summary of chemical and mineralogical properties of Martian surface dust is offered for the benefit of engineers or mission planners who are designing hardware or strategies for Mars surface exploration. For technical details and specialized explanations, references should be made to literature cited. Four sources used for information about Martian dust composition: (1) Experiments performed on the Mars surface by the Viking Landers 1 and 2 and Earth-based lab experiments attempting to duplicate these results; (2) Infrared spectrophotometry remotely performed from Mars orbit, mostly by Mariner 9; (3) Visible and infrared spectrophotometry remotely performed from Earth; and (4) Lab studies of the shergottite nakhlite chassignite (SNC) clan of meteorites, for which compelling evidence suggests origin on Mars. Source 1 is limited to fine grained sediments at the surface whereas 2 and 3 contain mixed information about surface dust (and associated rock) and atmospheric dust. Source 4 has provided surprisingly detailed information but investigations are still incomplete.

  12. Topography of the Martian tropical regions with ISM

    NASA Astrophysics Data System (ADS)

    Bibring, J.-P.; Erard, S.; Gondet, B.; Langevin, Y.; Soufflot, A.; Combes, M.; Cara, C.; Drossart, P.; Encrenaz, T.; Lellouch, E.; Rosenqvist, J.; Moroz, V. I.; Dyachkov, A. V.; Grygoriev, A. V.; Havinson, N. G.; Khatuntsev, I. V.; Kiselev, A. V.; Ksanfomality, L. V.; Nikolsky, Yu. V.; Masson, P.; Forni, O.; Sotin, C.

    1991-02-01

    The measurement of the CO2 column density on Mars, from the 2-micron band, in the Phobos/ISM spectra allows the determination of the altitude of the surface of Mars, with a horizontal spatial resolution of 20 km. The uncertainties involved in this method are described and compared with previous measurements of the Martian topography. Several topographic maps have been calculated, in the region of the high Martian volcanoes and Valles Marineris. Comparison with topographic maps derived from Mariner 9 and Viking measurements shows a good agreement. An average accuracy of about 400 m is obtained, which constitutes a significant improvement, compared with previous altimetry errors, of the order of 1 km. The method has a uniform accuracy over a full observation sequence (about 3000 km wide), and is complementary to the Viking photogrammetric measurements, more accurate on a 100 km scale.

  13. The Martian paleoclimate and enhanced atmospheric carbon dioxide

    NASA Technical Reports Server (NTRS)

    Cess, R. D.; Owen, T.; Ramanathan, V.

    1980-01-01

    Current evidence indicates that the Martian surface is abundant with water presently in the form of ice, while the atmosphere was at one time more massive with a past surface pressure of as much as 1 atm of CO2. In an attempt to understand the Martian paleoclimate, a past CO2-H2O greenhouse was modeled and global temperatures which are consistent with an earlier presence of liquid surface water are found in agreement with the extensive evidence for past fluvial erosion. An important aspect of the CO2-H2O greenhouse model is the detailed inclusion of CO2 hot bands. For a surface pressure of 1 atm of CO2, the present greenhouse model predicts a global mean surface temperature of 294 K, but if the hot bands are excluded, a surface temperature of only 250 K is achieved.

  14. Martian Radiation Environment: Model Calculations and Recent Measurements with "MARIE"

    NASA Technical Reports Server (NTRS)

    Saganti, P. B.; Cucinotta, F. A.; zeitlin, C. J.; Cleghorn, T. F.

    2004-01-01

    The Galactic Cosmic Ray spectra in Mars orbit were generated with the recently expanded HZETRN (High Z and Energy Transport) and QMSFRG (Quantum Multiple-Scattering theory of nuclear Fragmentation) model calculations. These model calculations are compared with the first eighteen months of measured data from the MARIE (Martian Radiation Environment Experiment) instrument onboard the 2001 Mars Odyssey spacecraft that is currently in Martian orbit. The dose rates observed by the MARIE instrument are within 10% of the model calculated predictions. Model calculations are compared with the MARIE measurements of dose, dose-equivalent values, along with the available particle flux distribution. Model calculated particle flux includes GCR elemental composition of atomic number, Z = 1-28 and mass number, A = 1-58. Particle flux calculations specific for the current MARIE mapping period are reviewed and presented.

  15. Factors Controlling the Position of the Martian Magnetic Pileup Boundary

    NASA Technical Reports Server (NTRS)

    Crider, D. H.; Acuna, M.; Vignes, D.; Krymskii, A.; Breus, T.; Ness, N.

    2003-01-01

    The magnetic pileup boundary (MPB) at Mars is the position where the dominant ion of the plasma changes from solar wind protons to heavy ions of planetary origin. As such, it is the obstacle to solar wind ions. We investigate the factors that influence the shape and position of the magnetic pileup boundary at Mars in order to better understand the Martian obstacle to the solar wind. Employing MGS data, we determine how the Martian MPB moves in response to factors including solar wind pressure and crustal magnetic fields. We also study the factors affecting the thickness of the MPB. Further, we compare the magnetic pileup boundary to the magnetic barrier at Venus. Direct comparison aids in our interpretation of the physics involved in the solar wind interaction with planets lacking a significant intrinsic magnetic field.

  16. Investigating the coupling between the Martian atmosphere and its subsurface

    NASA Astrophysics Data System (ADS)

    Paton, M.; Harri, A. M.; Mäkinen, T.

    2011-10-01

    In-situ measurements are necessary to provide ground truths for remote observations, to conduct focused investigations on local scales and working as a network to investigate large scale phenomenon and their relation to local scale processes [1]. In this work we are interested in the coupling between the Martian atmosphere and the subsurface in terms of the thermal and mass exchange processes as this is not fully understood yet. A thermal model combined with temperature measurements is a useful way to characterise the subsurface properties [2]. A model is developed that simulates heat transfer through convection and conduction. The model is applied to the temperatures measured by the Viking 1 footpad sensor that was in direct contact with the Martian surface. The sensor is shown to be in shadow and the thermal properties used in the model suggest the influence of the footpad thermal properties.

  17. Geochemistry and setting of Martian weathering: The Lafayette meteorite

    NASA Technical Reports Server (NTRS)

    Treiman, A. H.; Barrett, R. A.; Gooding, J. L.

    1992-01-01

    Lafayette, one of the SNC (martian) meteorites, contains preterrestrial alteration materials rich in smectite and ferric oxides. The compositions and textures of the veinlets suggest that they were formed in episodic alteration events by waters that contained a relatively small load of dissolved salts. The Lafayette achondrite, one of the nakhlites of probable martian origin, is an igneous rock consisting mostly of augite and olivine, with interstitial feldspar, sulfides (pyrite), high-Si glass, and other phases. Like Nakhla itself, Lafayette contains veinlets of hydrous alteration materials. We studied thin sections of sample ME2116 (Field Museum, Chicago), using scanning and transmission electron microscopy (SEM and TEM) with energy dispersive X-ray spectrometry (EDS).

  18. Microscopic Views of Martian Soils and Evidence for Incipient Diagenesis

    NASA Technical Reports Server (NTRS)

    Goetz, W.; Madsen, M. B.; Bridges, N.; Clark, B.; Edgett, K. S.; Fisk, M.; Grotzinger, J. P.; Hviid, S. F.; Meslin, P.-Y.; Ming, D. W.; Newsom, H.; Sullivan, R.; Vaniman, D.; Wiens, R.

    2014-01-01

    Mars landed missions returned im-ages at increasingly higher spatial resolution (Table 1). These images help to constrain the microstructure of Martian soils, i.e. the grain-by-grain association of chemistry and mineralogy with secondary properties, such as albedo, color, magnetic properties, and mor-phology (size, shape, texture). The secondary charac-teristics are controlled by mineralogical composition as well as the geo-setting (transport and weathering modes, e.g. water supply, pH, atmospheric properties, exposure to radiation, etc.). As of today this association is poorly constrained. However, it is important to un-derstand soil-forming processes on the surface of Mars. Here we analyze high-resolution images of soils re-turned by different landed missions. Eventually these images must be combined with other types of data (chemistry and mineralogy at small spatial scale) to nail down the microstructure of Martian soils.

  19. Mineral Biomarkers in Martian Meteorite Allan Hills 84001?

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  20. Weathering processes implied from analysis of small Martian avalanche chutes

    NASA Technical Reports Server (NTRS)

    Sullivan, R.

    1992-01-01

    It has been proposed that the smaller features of martian spur and gully slope morphology, located along the upper walls of Valles Marineris, are avalanche chutes. A three-dimensional stability back-analysis technique was developed and applied to these small avalanche chutes, yielding average values of cohesion and angle of internal friction for the mobile layer materials on these slopes at the time of each slope failure. Generally, the analysis showed that at the time of each slope failure material strengths had been reduced to those of moderately cohesive debris down through depths of tens of meters. These results have implications and possible constraints for the nature and rate of martian weathering processes.

  1. Extraterrestrial meteors: a martian meteor and its parent comet.

    PubMed

    Selsis, Franck; Lemmon, Mark T; Vaubaillon, Jérémie; Bell, James F

    2005-06-01

    Regular meteor showers occur when a planet approaches the orbit of a periodic comet--for example, the Leonid shower is evident around 17 November every year as Earth skims past the dusty trail of comet Tempel-Tuttle. Such showers are expected to occur on Mars as well, and on 7 March last year, the panoramic camera of Spirit, the Mars Exploration Rover, revealed a curious streak across the martian sky. Here we show that the timing and orientation of this streak, and the shape of its light curve, are consistent with the existence of a regular meteor shower associated with the comet Wiseman-Skiff, which could be characterized as martian Cepheids. PMID:15931208

  2. The Martian valley networks: Origin by niveo-fluvial processes

    NASA Technical Reports Server (NTRS)

    Rice, J. W., Jr.

    1993-01-01

    The valley networks may hold the key to unlocking the paleoclimatic history of Mars. These enigmatic landforms may be regarded as the Martian equivalent of the Rosetta Stone. Therefore, a more thorough understanding of their origin and evolution is required. However, there is still no consensus among investigators regarding the formation (runoff vs. sapping) of these features. Recent climatic modeling precludes warm (0 degrees C) globally averaged surface temperatures prior to 2 b.y. when solar luminosity was 25-30 percent less than present levels. This paper advocates snowmelt as the dominant process responsible for the formation of the dendritic valley networks. Evidence for Martian snowfall and subsequent melt has been discussed in previous studies.

  3. S.A.M., the Italian Martian Simulation Chamber

    NASA Astrophysics Data System (ADS)

    Galletta, G.; Ferri, F.; Fanti, G.; D'Alessandro, M.; Bertoloni, G.; Pavarin, D.; Bettanini, C.; Cozza, P.; Pretto, P.; Bianchini, G.; Debei, S.

    2006-12-01

    The Martian Environment Simulator (SAM “Simulatore di Ambiente Marziano”) is a interdisciplinary project of Astrobiology done at University of Padua. The research is aimed to the study of the survival of the microorganisms exposed to the “extreme” planetary environment. The facility has been designed in order to simulate Mars’ environmental conditions in terms of atmospheric pressure, temperature cycles and UV radiation dose. The bacterial cells, contained into dedicated capsules, will be exposed to thermal cycles simulating diurnal and seasonal Martian cycles. The metabolism of the different biological samples will be analysed at different phases of the experiment, to study their survival and eventual activity of protein synthesis (mortality, mutations and capability of DNA reparing). We describe the experimental facility and provide the perspectives of the biological experiments we will perform in order to provide hints on the possibility of life on Mars either autochthonous or imported from Earth.

  4. Studies of Martian polar regions. [using CO2 flow

    NASA Technical Reports Server (NTRS)

    Smith, C. I.; Clark, B. R.; Eschman, D. F.

    1974-01-01

    The flow law determined experimentally for solid CO2 establishes that an hypothesis of glacial flow of CO2 at the Martian poles is not physically unrealistic. Compression experiments carried out under 1 atmosphere pressure and constant strain rate conditions demonstrate that the strength of CO2 near its sublimation point is considerably less than the strength of water ice near its melting point. A plausible glacial model for the Martian polar caps was constructed. The CO2 deposited near the pole would have flowed outward laterally to relieve high internal shear stresses. The topography of the polar caps, and the uniform layering and general extent of the layered deposits were explained using this model.

  5. K, U, and Th behavior in Martian environmental conditions

    NASA Technical Reports Server (NTRS)

    Zolotov, M. YU.; Krot, T. V.; Moroz, L. V.

    1993-01-01

    The possibility of K, U, and Th content determination from orbit and in situ allows consideration of those elements as geochemical indicators in the planetary studies. In the case of Mars the unambiguous interpretations of such data in terms of igneous rocks are remarkably constrained by the widespread rock alteration and the existence of exogenic deposits. Besides, the terrestrial experience indicates that K, U, and Th contents could be used as indicators of environmental geochemical processes. Thus the determination of K, U, and Th contents in the Martian surface materials could provide the indirect data on the conditions of some exogenic geological processes. The speculations on the K, U, and Th behavior in the Martian environments show that aeolian and aqueous processes leads to the preferential accumulation of K, U, and Th in fine dust material. The separation of K, U, and Th on Mars is smaller in scale to that on Earth.

  6. Martian Methane From a Cometary Source: A Hypothesis

    NASA Technical Reports Server (NTRS)

    Fries, M.; Christou, A.; Archer, D.; Conrad, P.; Cooke, W.; Eigenbrode, J.; ten Kate, I. L.; Matney, M.; Niles, P.; Sykes, M.; Steele, A.; Treiman, A.

    2016-01-01

    In recent years, methane in the martian atmosphere has been detected by Earth-based spectroscopy, the Planetary Fourier Spectrometer on the ESA Mars Express mission, and the NASA Mars Science Laboratory. The methane's origin remains a mystery, with proposed sources including volcanism, exogenous sources like impacts and interplanetary dust, aqueous alteration of olivine in the presence of carbonaceous material, release from ancient deposits of methane clathrates, and/or biological activity. An additional potential source exists: meteor showers from the emission of large comet dust particles could generate martian methane via UV pyrolysis of carbon-rich infall material. We find a correlation between the dates of Mars/cometary orbit encounters and detections of methane on Mars. We hypothesize that cometary debris falls onto Mars during these interactions, generating methane via UV photolysis.

  7. Martian great dust storms - Interpretive axially symmetric models

    NASA Astrophysics Data System (ADS)

    Schneider, E. K.

    1983-08-01

    The Martian great dust storms are presently considered in light of the Schneider (1977) simplified theory of steady, nearly inviscid, thermally forced and axially symmetric atmospheric motions. A highly idealized calculation of atmospheric response to heating that is concentrated in a small latitude band is conducted, leading to the identification of qualitatively different local and global response regimes. Idealized model results indicate that subtropical latitudes are favored for the initiation of a dust-raising global dust storm. The steady, axially symmetric Martian response to solar forcing and modification to this response through an additional, latitudinally localized heat source are also discussed, and it is suggested that transition behavior similar to that of the more idealized model is to be expected in this case as well.

  8. Martian Surface Properties: Inferences from Resolved Differences in Crater Geometries

    NASA Technical Reports Server (NTRS)

    Valiant, G. J.; Stewart, S. T.

    2004-01-01

    Impact craters are a natural probe of planetary sub-surfaces, both from the excavated material and from crater geometries, which are sensitive to material properties of the target. One of the most intriguing aspects of Martian craters is the morphology of the ejecta blankets. All fresh and many older Martian craters larger than a few km are surrounded by ejecta blankets which appear fluidized, with morphologies believed to form by entrainment of liquid water. In addition to the ejecta morphology, quantitative information about the subsurface composition may be derived from geometrical measurements, e.g., rim uplift height and ejecta blanket volumes. In order to use craters to derive subsurface composition or test rampart morphology formation hypotheses, accurate measurements with quantified error estimates are required. We have developed and tested a toolkit for measurements of crater geometry using the MOLA altimetry data. Here, we present the results from geometry measurements on fresh craters in Lunae Planum and Utopia Planitia.

  9. The age of the carbonates in martian meteorite ALH84001

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    The age of secondary carbonate mineralization in the martian meteorite ALH84001 was determined to be 3.90 +/- 0.04 billion years by rubidium-strontium (Rb-Sr) dating and 4.04 +/- 0.10 billion years by lead-lead (Pb-Pb) dating. The Rb-Sr and Pb-Pb isochrons are defined by leachates of a mixture of high-graded carbonate (visually estimated as approximately 5 percent), whitlockite (trace), and orthopyroxene (approximately 95 percent). The carbonate formation age is contemporaneous with a period in martian history when the surface is thought to have had flowing water, but also was undergoing heavy bombardment by meteorites. Therefore, this age does not distinguish between aqueous and impact origins for the carbonates.

  10. Extraterrestrial meteors: a martian meteor and its parent comet.

    PubMed

    Selsis, Franck; Lemmon, Mark T; Vaubaillon, Jérémie; Bell, James F

    2005-06-01

    Regular meteor showers occur when a planet approaches the orbit of a periodic comet--for example, the Leonid shower is evident around 17 November every year as Earth skims past the dusty trail of comet Tempel-Tuttle. Such showers are expected to occur on Mars as well, and on 7 March last year, the panoramic camera of Spirit, the Mars Exploration Rover, revealed a curious streak across the martian sky. Here we show that the timing and orientation of this streak, and the shape of its light curve, are consistent with the existence of a regular meteor shower associated with the comet Wiseman-Skiff, which could be characterized as martian Cepheids.

  11. The Martian near surface environment: Analysis of Antarctic soils and laboratory experiments on putative Martian organics

    NASA Astrophysics Data System (ADS)

    Archer, Paul Douglas, Jr.

    Understanding the physical properties as well as the potential for organic material in the Martian near-surface environment can give us a glimpse into the history of the site with regards to water, soil formation processes, as well as the conditions necessary for life. This work is done to support the interpretation of data from the Phoenix Mars Lander as well as other past and future landed missions. The Antarctic Dry Valleys are a hyper-arid cold polar desert that is the most Mars-like place on Earth. Soils from two different soil and climate regimes are analyzed to determine their physical properties such as mineralogy, particle size, shape, color, and specific surface area. These data are used to describe the sample locations in Antarctica and infer properties of Martian soils by comparison to Antarctic sites. I find that the particle size distribution can be used to determine the water history of the site and that the behavior of soluble species in the soil can also be used to trace the movement of water through the soil and could be instructive in understanding how soil organic material is processed by the environment. Continuing with the theme of soil organic matter, we revisit the Viking conclusions with regards to organics on Mars and look at the Phoenix data on the same subject. First, we assume that Mars receives organic material from meteoritic infall. These organics will be processed by chemical oxidants as well as UV light down to 200 nm. Chemical oxidation is predicted to produce molecules such as mellitic acid, which could preserve up to 10% of the original organic mass. Using mellitic acid and other similar organic molecules, we irradiate these molecules with Mars-like ultraviolet light, analyzing the gases that come off as irradiation takes place. We find that organic molecules can survive Mars-like UV conditions as layers of UV-resistant organics build up, shielding the remaining organic material. Additionally, the gas products of irradiation

  12. The Martian Plasma Environment: Model Calculations and Observations

    NASA Astrophysics Data System (ADS)

    Lichtenegger, H. I. M.; Dubinin, E.; Schwingenschuh, K.; Riedler, W.

    Based on a modified version of the model of an induced martian magnetosphere developed by Luhmann (1990), the dynamics and spatial distribution of different planetary ion species is examined. Three main regions are identified: A cloud of ions travelling along cycloidal trajectories, a plasma mantle and a plasma sheet. The latter predominantly consists of oxygen ions of ionospheric origin with minor portions of light particles. Comparison of model results with Phobos-2 observations shows reasonable agreement.

  13. Paleointensity of the Martian field from SQUID Microscopy

    NASA Astrophysics Data System (ADS)

    Weiss, B. P.; Fong, L. E.; Lima, E. A.; Baudenbacher, F. J.; Vali, H.

    2005-12-01

    Crustal magnetic anomalies in the southern Martian hemisphere have intensities an order of magnitude larger than typical crustal anomalies on Earth. Two possible explanations for this difference are that compared to the present-day Earth, Mars has either (i) larger amounts of crustal ferromagnetic minerals or (ii) the crust was magnetized by a larger paleofield. ALH84001, the only pre-Amazonian Martian meteorite, possesses a stable magnetization dating to 4 Ga or earlier. Previous paleomagnetic studies with SQUID moment magnetometers on bulk ALH84001 grains have estimated that the paleointensity of the field which magnetized the meteorite was between 0.1-1 times that of the Earth's present field. However, these estimates may be lower limits on the true paleointensity because the orientation of the magnetization in ALH84001 is spatially heterogeneous on the submillimeter scale. This complication could have profound implications for hypothesis (ii) above. Here we first demonstrate that superconducting quantum interference device (SQUID) microscopy can recover the same magnetization intensity and direction of a well characterized modern-day terrestrial basalt as that measured with a 2G Enterprises SQUID moment magnetometer. A SQUID microscope paleointensity analysis of this basalt gives the expected present day field intensity of a few tens of microtesla. We further show that our new high resolution SQUID microscopy study of ALH84001, which has mapped its heterogeneous magnetization with the highest resolution yet (0.1 mm), favors the upper range of previous paleointensity estimates for the 4 Ga Martian paleofield (e.g., within a factor of several of that of the present-day Earth). However, this field, were it dynamo in origin, is still too weak to easily explain the intensity of the Martian magnetic anomalies.

  14. Phobos and Deimos: A base for sampling the Martian past

    NASA Technical Reports Server (NTRS)

    Singer, S. F.

    1987-01-01

    Future exploration of Mars is summed up by the proposal that the Martian satellites provide an ideal base for exploring the surface of Mars. For example, a manned base on Deimos could direct a series of unmanned rovers and sample recovery operations, providing an immediate feedback to the operation. Samples analyzed in such an environment would be fresh, and most importantly, would not require quarantine.

  15. Comparing Martian chaotic terrains with their terrestrial analogues

    NASA Astrophysics Data System (ADS)

    Rossi, A. P.; Chicarro, A.; Huvenna, V.; Henriet, J. P.; Di Lorenzo, S.; Neukum, G.; HRSC Co-Investigator Team

    2005-08-01

    Martian chaotic terrains have some morphological resemblance with certain terrestrial submarine slope failures [1]. We are comparing a few chaos areas on Mars with an ancient slope failure in the Porcupine Basin, offshore SW Ireland [2]. Disrupted terrains (chaos) occur extensively on Mars, even if most strictly named chaos are concentrated in the outflow channels source region, close to the Eastern part of Valles Marineris canyon system. Mesas in Martian chaos areas are usually up to a few tens of km wide, whereas knobs are usually from a few hundred meters to a few km. Instead, blocks in the Porcupine slope failure are up to a few hundred meters wide. The blocks (or mesas) in Porcupine slope failure occupy an average of about 42% of the area. The percentage of undisrupted mesas however varies across the slope failure. Preliminary measurements in Aureum and Hydaspis chaos on Mars show comparable but slightly lower percentage of preserved mesas (25-30%). Locally in chaotic terrain-like areas such as the area north of Deuteronilus Mensae, the percentage of preserved blocks is around 15%, possibly due to further degradation and erosion of the mesas. Fluidization possibly occurs on both Martian chaotic terrains and in this terrestrial submarine failure. It is not clear yet whether basal sliding, present in the Porcupine Basin, has occurred in certain Martian chaotic terrains, and therefore we are using HRSC data to provide constraints. Multiple processes, such as rapid fluidization and sapping, could have produced polygonal morphologies on Mars. The Porcupine Basin slope failure could be of help in understanding the mechanism of chaos formation on Mars. References: [1] Nummedal, D. and Prior D. B., 1981, Icarus 45, 77-86. [2] Huvenne, V.A.I., Croker, P.F. & Henriet, J. P., 2002, Terra Nova, 14, 33-40.

  16. Martian geomorphology and its relation to subsurface volatiles

    NASA Technical Reports Server (NTRS)

    Clifford, Stephen M. (Editor); Rossbacher, Lisa A. (Editor); Zimbelman, James R. (Editor)

    1986-01-01

    Martian volatile inventory, planetary climatic and atmospheric evolution, and the interpretation of various remote sensing data were discussed. A number of morphologies that were cited as potential indicators of subsurface volatiles were reviewed. Rampart craters and terrain softening were the focus of more in-depth discussion because of the popular attention they have received and the fact that their areal distributions are by far the most extensive of all the proposed indicators.

  17. Microwave Palaeointensity Experiments On Terrestrial and Martian Material

    NASA Astrophysics Data System (ADS)

    Shaw, J.; Hill, M.; Gratton, M.

    The microwave palaeointensity technique was developed in Liverpool University (Walton et al 1996) and has successfully been applied to archaeological ceramics and recent lavas (Shaw et al 1996, 1999.; Hill et al 1999,2000). These published results show that microwave analysis provides accurate palaeointensity determinations com- bined with a very high success rate. Most recently the technique has been successfully applied to Martian material (Shaw et al, 2001) to look for the existence of an internal Martian dynamo early in Martian history. New experiments have been carried out us- ing microwaves to demagnetise synthetic muti-component TRM's and new palaeoin- tensity experiments providing a comparison between microwave analysis of laboratory TRM's and conventional thermal Thellier analysis of microwave generated mTRM's. These experiments demonstrate the equivalence of microwave and thermally gener- ated TRM's. D. Walton, S Snape, T.C. Rolph, J. Shaw and J.A. Share, Application of ferromagnetic resonance heating to palaeointensity determinations.1996, Phys Earth Planet Int,94, 183-186. J. Shaw, D. Walton, S Yang, T.C.Rolph, and J.A. Share. Microwave Archaeointensities from Peruvian Ceramics. 1996, Geophys. J. Int,124,241-244 J. Shaw, S. Yang, T. C. Rolph, and F. Y. Sun. A comparison of archaeointensity results from Chinese ceramics using Microwave and conventional ThellierSs and ShawSs methods.,1999, G J Int.136, 714-718 M. Hill, and J. Shaw, 1999, Palaeointensity results for Historic Lavas from Mt. Etna using microwave demagnetisation/remagnetisation in a modified Thellier type exper- iment. G. J. Int, 139, 583-590 M. J. Hill, and J. Shaw, 2000. Magnetic field intensity study of the 1960 Kilauea lava flow, Hawaii, using the microwave palaeointensity technique, Geophys. J. Int., 142, 487-504. J. Shaw, M. Hill, and S. J. Openshaw, 2001, Investigating the ancient Martian magnetic field using microwaves, Earth and Planetary Science Letters 190 (2001) 103-109

  18. Solder joint fatigue analysis under low temperature Martian conditions

    NASA Technical Reports Server (NTRS)

    Tudryn, Carissa

    2006-01-01

    Electronics, without requiring heater power or enclosure in a centralized 'warm electronics box,' will need to survive mean surface temperatures of -120 degrees Celsius to +20 degrees Celsius for an extended Martian mission and an operational temperature up to 85 degrees Celsisus. Since these electronics will need to survive extended cycles under these conditions, fatigue is a significant concern. The solder joint reliability of connectors on a printed wiring board was investigated.

  19. Seasonal Variation of Martian Pick-up Ions

    NASA Astrophysics Data System (ADS)

    Yamauchi, M.; Hara, T.; Lundin, R.; Dubinin, E.; Fedorov, A.; Sauvaud, J.-A.; Frahm, R.; Ramstad, R.; Futaana, Y.; Holmstrom, M.; Barabash, S.

    2015-10-01

    Statistics of Mars Express (MEX) ion mass analyser(IMA) data shows that ion production from exospheric hydrogen depends more on the Sun-Mars distance than the solar cycle phase or winter-summer hemispheric difference. This indicates that the EUV is not the only driver of the production of cold, exospheric-origin ions, and that the extension of the exosphere is strongly influenced by total irradiance that carries the majority of the solar energy to the Martian atmosphere.

  20. Rocket Cratering in Simulated Lunar and Martian Environments

    NASA Technical Reports Server (NTRS)

    Immer, Christopher; Metzger, Phillip

    2010-01-01

    With NASA's planned return to the moon and possibly with lunar outposts being formed, repeated landings at the same site will be necessary. Understanding rocket plume interaction with lunar and Martian surfaces is of paramount importance in order to safely land and protect hardware surrounding the landing site. This work will report on results of three small experiments intended to explore plume impingement onto lunar and Martian surfaces: Handheld Observation of Scour Holes (HOOSH), Handheld Angle of Repose Measurements of Lunar Simulants (HARMLuS), and Mars Architecture Team study (MATS). The first two experiments were performed during two sorties of reduced gravity flights. HOOSH was designed to investigate crater formation as a function of gravitational level (lunar and Martian gravity). HARMLuS was designed to measure the Angle of Failure (related to the angle of repose) at lunar and Martian gravity. Both experiments have complex findings indicative of the hysteretic behavior of granular materials, especially resulting from reduced gravity. The MATS experiment was designed to investigate the effects of regolith compaction on the granular mechanics of crater formation . In general, the granular mechanics is a much stronger function of compaction than gravitation acceleration. Crater formation is greatly enhanced at reduced gravity (resulting in much larger craters). The angle of failure of the lunar simulants increases with decreasing gravitational acceleration, and occasionally becomes infinite for some compactions at lunar gravity. The angle of failure also increases with increasing compaction. While compaction does play a role in the time development of crater formation, the asymptotic behavior is largely unaffected.

  1. Possible contemporary evaporites formation at the Martian Northern Polar Cap

    NASA Astrophysics Data System (ADS)

    Losiak, Anna; Czechowski, Leszek

    Evaporitic minerals are abundant on the surface of Mars (e.g., Wentworth et al. 2005, Velbel 2012, Clark and Van Hart 1981, Wang et al. 2006, Kuzmin et al. 2009), especially within the Circumpolar Dune Field and on the Northern Ice Cap itself (e.g., Langevin et al., 2005, Roach et al. 2007, Horgan et al. 2009, Masse et al. 2010, 2012). Most of their proposed formation mechanisms require significant amounts of liquid water and are thus not possible under current Martian conditions (Arvidson et al. 2006, Andrews-Hanna et al. 2007, Fishbaugh et al. 2007, Szynkiewicz et al. 2010). Some authors have considered the potential role of ice and ice- or snowmelt-related alteration in the weathering of Martian materials (e.g., Catling et al. 2006, Zolotov and Mironenko 2007, Niles and Michalski 2009, Masse et al. 2010). However, none of those studies discussed details of the process leading to the formation of the evaporites or the timing of the processes. The aim of this paper is to model numerically if the current radiant heating is sufficient to melt a thin layer of ice surrounding a single dust grain exposed within the south facing side of the Martian North Polar Cap trench. The results of our initial study suggest that for dust grains with basaltic properties and ice with low values of coefficient of heat conduction, and solar constant = 492 W/m2 liquid water may exist below a dust grain for up to 4 hours a sol. This suggest that contemporary evaporites formation on Martian Polar Cap is possible.

  2. Martian sub-crustal stress from gravity and topographic models

    NASA Astrophysics Data System (ADS)

    Tenzer, Robert; Eshagh, Mehdi; Jin, Shuanggen

    2015-09-01

    The latest Martian gravity and topographic models derived from the Mars Orbiter Laser Altimeter and the Mars Global Surveyor spacecraft tracking data are used to compute the sub-crustal stress field on Mars. For this purpose, we apply the method for a simultaneous determination of the horizontal sub-crustal stress component and the crustal thickness based on solving the Navier-Stokes problem and incorporating the Vening Meinesz-Moritz inverse problem of isostasy. Results reveal that most of the Martian sub-crustal stress is concentrated in the Tharsis region, with the most prominent signatures attributed to a formation of Tharsis major volcanoes followed by crustal loading. The stress distribution across the Valles Marineris rift valleys indicates extensional tectonism. This finding agrees with more recent theories of a tectonic origin of Valles Marineris caused, for instance, by a crustal loading of the Tharsis bulge that resulted in a regional trusting and folding. Aside from these features, the Martian stress field is relatively smooth with only a slightly enhanced pattern of major impact basins. The signatures of active global tectonics and polar ice load are absent. Whereas the signature of the hemispheric dichotomy is also missing, the long-wavelength spectrum of the stress field comprises the signature of additional dichotomy attributed to the isostatically uncompensated crustal load of Tharsis volcanic accumulations. These results suggest a different origin of the Earth's and Martian sub-crustal stress. Whereas the former is mainly related to active global tectonics, the latter is generated by a crustal loading and regional tectonism associated with a volcanic evolution on Mars. The additional sub-crustal stress around major impact basins is likely explained by a crustal extrusion after impact followed by a Moho uplift.

  3. Low computation vision-based navigation for a Martian rover

    NASA Technical Reports Server (NTRS)

    Gavin, Andrew S.; Brooks, Rodney A.

    1994-01-01

    Construction and design details of the Mobot Vision System, a small, self-contained, mobile vision system, are presented. This system uses the view from the top of a small, roving, robotic vehicle to supply data that is processed in real-time to safely navigate the surface of Mars. A simple, low-computation algorithm for constructing a 3-D navigational map of the Martian environment to be used by the rover is discussed.

  4. Exposure and Terrestrial Histories of New Lunar and Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Nishiizumi, K.; Hillegonds, D. J.; McHargue, L. R.; Jull, A. J. T.

    2004-01-01

    Cosmogenic nuclide studies of lunar and Martian meteorites have contributed significantly to our understanding of these objects. By measuring a combination of cosmogenic stable- and radionuclides, we can determine a number of important properties of those meteorites. Most lunar meteorites have complex cosmic ray exposure histories, having been exposed both at some depth on the lunar surface (2 irradiation) before their ejection and as small bodies in space (4 irradiation) during transport from the Moon to the Earth. On the other hand, we have not observed evidence of complex exposure history for any Martian meteorites, so far. These exposures were then followed by residence on Earth s surface, a time commonly referred to as the terrestrial age. In addition to their complement of galactic cosmic ray (GCR) produced nuclides some lunar and Martian meteorites contain nuclides produced by solar cosmic rays (SCR). Unraveling the complex history of these objects requires the measurement of at least four cosmogenic nuclides. The specific goals of these measurements are to constrain or set limits on the following shielding or exposure parameters: (1) the depth of the sample at the time of ejection from the Moon or Mars; (2) the transit time (4 exposure age) from ejection off the lunar or Martian surface to the time of capture by the Earth and (3) the terrestrial residence time. The sum of the transit time and residence time yield an ejection age. The ejection age, in conjunction with the sample depth on the Moon or Mars, can then be used to model impact and ejection mechanisms.

  5. Is ground ice stable near the Martian equator?

    NASA Technical Reports Server (NTRS)

    Paige, D. A.

    1992-01-01

    Determining the present distribution of subsurface water ice on Mars will undoubtedly be a prime objective for future spacecraft missions. Past theoretical studies have predicted that Martian ground ice should be stable to evaporation only at latitudes poleward of approximately +/- 50 deg. Presented here are a new set of calculations which show that bright surficial dust deposits can protect subsurface ice deposits from evaporation at much lower latitudes than previously expected.

  6. Considerations Concerning the Development and Testing of In-situ Materials for Martian Exploration

    NASA Technical Reports Server (NTRS)

    Kim, M.-H. Y.; Heilbronn, L.; Thibeault, S. A.; Simonsen, L. C.; Wilson, J. W.; Chang, K.; Kiefer, R. L.; Maahs, H. G.

    2000-01-01

    Natural Martian surface materials are evaluated for their potential use as radiation shields for manned Mars missions. The modified radiation fluences behind various kinds of Martian rocks and regolith are determined by solving the Boltzmann equation using NASA Langley s HZETRN code along with the 1977 Solar Minimum galactic cosmic ray environmental model. To make structural shielding composite materials from constituents of the Mars atmosphere and from Martian regolith for Martian surface habitats, schemes for synthesizing polyimide from the Mars atmosphere and for processing Martian regolith/polyimide composites are proposed. Theoretical predictions of the shielding properties of these composites are computed to assess their shielding effectiveness. Adding high-performance polymer binders to Martian regolith to enhance structural properties enhances the shielding properties of these composites because of the added hydrogenous constituents. Laboratory testing of regolith simulant/polyimide composites is planned to validate this prediction.

  7. An attempt to comprehend Martian weathering conditions through the analysis of terrestrial palagonite samples

    NASA Technical Reports Server (NTRS)

    Douglas, C.; Wright, I. P.; Bell, J. B.; Morris, R. V.; Golden, D. C.; Pillinger, C. T.

    1993-01-01

    Spectroscopic observations of the Martian surface in the invisible to near infrared (0.4-1.0 micron), coupled with measurements made by Viking, have shown that the surface is composed of a mixture of fine-grained weathered and nonweathered minerals. The majority of the weathered components are thought to be materials like smectite clays, scapolite, or palagonite. Until materials are returned for analysis there are two possible ways of proceeding with an investigation of Martian surface processes: (1) the study of weathering products in meteorites that have a Martian origin (SNC's), and (2) the analysis of certain terrestrial weathering products as analogs to the material found in SNC's, or predicted to be present on the Martian surface. We describe some preliminary measurements of the carbon chemistry of terrestrial palagonite samples that exhibit spectroscopic similarities with the Martian surface. The data should aid the understanding of weathering in SNC's and comparisons between terrestrial palagonites and the Martian surface.

  8. Martian Radiative Transfer Modeling Using the Optimal Spectral Sampling Method

    NASA Technical Reports Server (NTRS)

    Eluszkiewicz, J.; Cady-Pereira, K.; Uymin, G.; Moncet, J.-L.

    2005-01-01

    The large volume of existing and planned infrared observations of Mars have prompted the development of a new martian radiative transfer model that could be used in the retrievals of atmospheric and surface properties. The model is based on the Optimal Spectral Sampling (OSS) method [1]. The method is a fast and accurate monochromatic technique applicable to a wide range of remote sensing platforms (from microwave to UV) and was originally developed for the real-time processing of infrared and microwave data acquired by instruments aboard the satellites forming part of the next-generation global weather satellite system NPOESS (National Polarorbiting Operational Satellite System) [2]. As part of our on-going research related to the radiative properties of the martian polar caps, we have begun the development of a martian OSS model with the goal of using it to perform self-consistent atmospheric corrections necessary to retrieve caps emissivity from the Thermal Emission Spectrometer (TES) spectra. While the caps will provide the initial focus area for applying the new model, it is hoped that the model will be of interest to the wider Mars remote sensing community.

  9. Martian zeolites as a source of atmospheric methane

    NASA Astrophysics Data System (ADS)

    Mousis, Olivier; Simon, Jean-Marc; Bellat, Jean-Pierre; Schmidt, Frédéric; Bouley, Sylvain; Chassefière, Eric; Sautter, Violaine; Quesnel, Yoann; Picaud, Sylvain; Lectez, Sébastien

    2016-11-01

    The origin of the martian methane is still poorly understood. A plausible explanation is that methane could have been produced either by hydrothermal alteration of basaltic crust or by serpentinization of ultramafic rocks producing hydrogen and reducing crustal carbon into methane. Once formed, methane storage on Mars is commonly associated with the presence of hidden clathrate reservoirs. Here, we alternatively suggest that chabazite and clinoptilolite, which belong to the family of zeolites, may form a plausible storage reservoir of methane in the martian subsurface. Because of the existence of many volcanic terrains, zeolites are expected to be widespread on Mars and their Global Equivalent Layer may range up to more than ∼1 km, according to the most optimistic estimates. If the martian methane present in chabazite and clinoptilolite is directly sourced from an abiotic source in the subsurface, the destabilization of a localized layer of a few millimeters per year may be sufficient to explain the current observations. The sporadic release of methane from these zeolites requires that they also remained isolated from the atmosphere during its evolution. The methane release over the ages could be due to several mechanisms such as impacts, seismic activity or erosion. If the methane outgassing from excavated chabazite and/or clinoptilolite prevails on Mars, then the presence of these zeolites around Gale Crater could explain the variation of methane level observed by Mars Science Laboratory.

  10. The viability of photovoltaics on the Martian surface

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Perez-Davis, Marla E.

    1994-01-01

    The viability of photovoltaics (PV) on the Martian surface may be determined by their ability to withstand significant degradation in the Martian environment. Probably the greatest threat is posed by fine dust particles which are continually blown about the surface of the planet. In an effort to determine the extent of the threat, and to investigate some abatement strategies, a series of experiments were conducted in the Martian Surface Wind Tunnel (MARSWIT) at NASA Ames Research Center. The effects of dust composition, particle size, wind velocity, angle of attack, and protective coatings on the transmittance of light through PV coverglass were determined. Both initially clear and initially dusted samples were subjected both to clear winds and simulated dust storms in the MARSWIT. It was found that wind velocity, particle size, and angle of attack are important parameters affecting occlusion of PV surfaces, while dust composition and protective coatings were not. Neither induced turbulence nor direct current biasing up to 200 volts were effective abatement techniques. Abrasion diffused the light impinging on the PV cells, but did not reduce total coverglass transmittance by more than a few percent.

  11. Modeling the Martian climate with a new general circulation model

    NASA Astrophysics Data System (ADS)

    Urata, R.; Toon, O. B.

    2009-12-01

    We have adapted the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM3.0) to Martian conditions. Several modifications to the original model have been made. These include adjusting the physical parameters to Mars-like values, changing atmospheric composition, changing the calendar to cover a Martian year, and the addition of a carbon dioxide condensation scheme. The Martian atmosphere is composed of 95% carbon dioxide, and as much as 25% of the atmosphere can condense out at the winter pole so it is important to include the carbon dioxide condensation in the model. We plan to use the model to simulate impacts on Mars during the late Noachian. As a reference point we have performed some climate simulations with a 500 mbar carbon dioxide atmosphere. The results will be presented at the meeting. Currently a few general circulation models are available for Mars. However instead of using one of these previously developed models, we have chosen to develop our own based off of CAM3 for a number of reasons. These include the model’s support for multi-processor runs, the model’s compatibility with other models including land, aerosol, and chemistry, and the fact many in our group already use the Earth version of this model, so we are familiar with it. During the development of our model, we have been in contact with NCAR, and have plans to make the model readily available to the public through NCAR.

  12. The physics of Martian weather and climate: a review

    NASA Astrophysics Data System (ADS)

    Read, P. L.; Lewis, S. R.; Mulholland, D. P.

    2015-12-01

    The planet Mars hosts an atmosphere that is perhaps the closest in terms of its meteorology and climate to that of the Earth. But Mars differs from Earth in its greater distance from the Sun, its smaller size, its lack of liquid oceans and its thinner atmosphere, composed mainly of CO2. These factors give Mars a rather different climate to that of the Earth. In this article we review various aspects of the martian climate system from a physicist’s viewpoint, focusing on the processes that control the martian environment and comparing these with corresponding processes on Earth. These include the radiative and thermodynamical processes that determine the surface temperature and vertical structure of the atmosphere, the fluid dynamics of its atmospheric motions, and the key cycles of mineral dust and volatile transport. In many ways, the climate of Mars is as complicated and diverse as that of the Earth, with complex nonlinear feedbacks that affect its response to variations in external forcing. Recent work has shown that the martian climate is anything but static, but is almost certainly in a continual state of transient response to slowly varying insolation associated with cyclic variations in its orbit and rotation. We conclude with a discussion of the physical processes underlying these long- term climate variations on Mars, and an overview of some of the most intriguing outstanding problems that should be a focus for future observational and theoretical studies.

  13. Does life's rapid appearance imply a Martian origin?

    PubMed

    Davies, P C W

    2003-01-01

    The hypothesis that life's rapid appearance on Earth justifies the belief that life is widespread in the universe has been investigated mathematically by Lineweaver and Davis (Astrobiology 2002;2:293-304). However, a rapid appearance could also be interpreted as evidence for a nonterrestrial origin. I attempt to quantify the relative probabilities for a non-indigenous versus indigenous origin, on the assumption that biogenesis involves one or more highly improbable steps, using a generalization of Carter's well-known observer-selection argument. The analysis is specifically applied to a Martian origin of life, with subsequent transfer to Earth within impact ejecta. My main result is that the relatively greater probability of a Martian origin rises sharply as a function of the number of difficult steps involved in biogenesis. The actual numerical factor depends on what is assumed about conditions on early Mars, but for a wide range of assumptions a Martian origin of life is decisively favored. By contrast, an extrasolar origin seems unlikely using the same analysis. These results complement those of Lineweaver and Davis.

  14. Potential Influence of Perchlorate on Organic Carbon in Martian Regolith

    NASA Astrophysics Data System (ADS)

    Oze, C.; Vithanage, M. S.; Kumarathilaka, P. R.; Indraratne, S.; Horton, T. W.

    2014-12-01

    Perchlorate is a strong oxidizer present at elevated concentrations in surface martian regolith. Chemical and isotopic modification of potential organic carbon with perchlorate in martian regolith during H2O(l) interactions is unknown. Here we assess the relationship between martian levels of perchlorate and organic carbon present in life harbouring geologic material from Earth. These materials represent chemical (i.e., processed serpentine soils from Sri Lanka) and temperature (i.e., hydrothermal jarosite/goethite deposit from White Island, New Zealand) extremes to where life exists on Earth. Preliminary evidence demonstrates that organic carbon decreases and δ13C values are modified for ultramafic sediment in both perchlorate kinetic and incubation experiments. In hydrothermal jarosite/goethite with microbial communities present, total and organic carbon is maintained and little modification in δ13C values is apparent. These preliminary results suggest that surface hydrothermal deposits with mineralogically 'protected' organic carbon are preferable sites to assess the potential of life on Mars.

  15. Response of terrestrial microorganisms to a simulated Martian environment

    NASA Technical Reports Server (NTRS)

    Foster, T. L.; Winans, L., Jr.; Casey, R. C.; Kirschner, L. E.

    1978-01-01

    Soil samples from Cape Canaveral were subjected to a simulated Martian environment and assayed periodically over 45 days to determine the effect of various environmental parameters on bacterial populations. The simulated environment was based on the most recent available data, prior to the Viking spacecraft, describing Martian conditions and consisted of a pressure of 7 millibars, an atmosphere of 99.9% CO2 and 0.1% O2, a freeze-thaw cycle of -65 C for 16 h and 24 C for 8 h, and variable moisture and nutrients. Reduced pressure had a significant effect, reducing growth under these conditions. Slight variations in gaseous composition of the simulated atmosphere had negligible effect on growth. The freeze-thaw cycle did not inhibit growth, but did result in a slower rate of decline after growth had occurred. Dry samples exhibited no change during the 45-day experiment, indicating that the simulated Martian environment was not toxic to bacterial populations. Psychrotrophic organisms responded more favorably to this environment than mesophiles, although both types exhibited increases of approximately 3 logs in 7 to 14 days when moisture and nutrients were available.

  16. Implications of an impact origin for the martian hemispheric dichotomy.

    PubMed

    Nimmo, F; Hart, S D; Korycansky, D G; Agnor, C B

    2008-06-26

    The observation that one hemisphere of Mars is lower and has a thinner crust than the other (the 'martian hemispheric dichotomy') has been a puzzle for 30 years. The dichotomy may have arisen as a result of internal mechanisms such as convection. Alternatively, it may have been caused by one or several giant impacts, but quantitative tests of the impact hypothesis have not been published. Here we use a high-resolution, two-dimensional, axially symmetric hydrocode to model vertical impacts over a range of parameters appropriate to early Mars. We propose that the impact model, in addition to excavating a crustal cavity of the correct size, explains two other observations. First, crustal disruption at the impact antipode is probably responsible for the observed antipodal decline in magnetic field strength. Second, the impact-generated melt forming the northern lowlands crust is predicted to derive from a deep, depleted mantle source. This prediction is consistent with characteristics of martian shergottite meteorites and suggests a dichotomy formation time approximately 100 Myr after martian accretion, comparable to that of the Moon-forming impact on Earth.

  17. Degradation of Organics in a Glow Discharge Under Martian Conditions

    NASA Technical Reports Server (NTRS)

    Hintze, P. E.; Calle, L. M.; Calle, C. I.; Buhler, C. R.; Trigwell, S.; Starnes, J. W.; Schuerger, A. C.

    2006-01-01

    The primary objective of this project is to understand the consequences of glow electrical discharges on the chemistry and biology of Mars. The possibility was raised some time ago that the absence of organic material and carbonaceous matter in the Martian soil samples studied by the VikinG Landers might be due in part to an intrinsic atmospheric mechanism such as glow discharge. The high probability for dust interactions during Martian dust storms and dust devils, combined with the cold, dry climate of Mars most likely results in airborne dust that is highly charged. Such high electrostatic potentials generated during dust storms on Earth are not permitted in the low-pressure CO2 environment on Mars; therefore electrostatic energy released in the form of glow discharges is a highly likely phenomenon. Since glow discharge methods are used for cleaning and sterilizing surfaces throughout industry, the idea that dust in the Martian atmosphere undergoes a cleaning action many times over geologic time scales appears to be a plausible one.

  18. Martian canyons and African rifts: Structural comparisons and implications

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    1978-01-01

    The resistant parts of the canyon walls of the Martian rift complex Valled Marineris were used to infer an earlier, less eroded reconstruction of the major roughs. The individual canyons were then compared with individual rifts of East Africa. When measured in units of planetary radius, Martian canyons show a distribution of lengths nearly identical to those in Africa, both for individual rifts and for compound rift systems. A common mechanism which scales with planetary radius is suggested. Martian canyons are significantly wider than African rifts. The overall pattern of the rift systems of Africa and Mars are quite different in that the African systems are composed of numerous small faults with highly variable trend. On Mars the trends are less variable; individual scarps are straighter for longer than on earth. This is probably due to the difference in tectonic histories of the two planets: the complex history of the earth and the resulting complicated basement structures influence the development of new rifts. The basement and lithosphere of Mars are inferred to be simple, reflecting a relatively inactive tectonic history prior to the formation of the canyonlands.

  19. Martian canyons and African rifts - Structural comparisons and implications

    NASA Technical Reports Server (NTRS)

    Frey, H.

    1979-01-01

    The resistant parts of the canyon walls of the Martian rift complex Valles Marineris have been used to infer an earlier, less eroded reconstruction of the major troughs. The individual canyons are compared with individual rifts of East Africa. When measured in units of planetary radius, Martian canyons show a distribution of lengths nearly identical to those in Africa, both for individual rifts and for compound rift systems. A common mechanism which scales with planetary radius is suggested. Martian canyons are significantly wider than African rifts. This is consistent with the longstanding idea that rift width is related to crustal thickness: most evidence favors a crust on Mars at least 50% thicker than that of Africa. The overall patterns of the rift systems of Africa and Mars are quite different in that the African systems are composed of numerous small faults with highly variable trend. On Mars the trends are less variable; individual scraps are straighter for longer than on earth. The basement and lithosphere of Mars are inferred to be simple, reflecting a relatively inactive tectonic history prior to the formation of the canyonlands.

  20. Human locomotion and workload for simulated lunar and Martian environments.

    PubMed

    Newman, D J; Alexander, H L

    1993-08-01

    Human locomotion in simulated lunar and Martian environments is investigated. A unique human-rated underwater treadmill and an adjustable ballasting harness simulate partial gravity in order to better understand how gravity determines the biomechanics and energetics of human locomotion. This study has two research aspects, biomechanics and energetics. The fundamental biomechanics measurements are continuously recorded vertical forces as exerted by subjects of the treadmill which is instrumented with a force platform. Experimental results indicate that peak vertical force and stride frequency decrease as the gravity level is reduced. Foot contact time is independent of gravity level. Oxygen uptake measurements, VO2, constitute the energetics, or workload, data for this study. As theory predicts, locomotion energy requirements for lunar (1/6-g) and Martian (3/8-g) gravity levels are significantly less than at 1-g. The observed variation in workload with gravity level is nonmonotonic, however, in over half the subject population. The hypothesis is offered that energy expenditure increases for lunar, as compared with Martian, locomotion due to the subject "wasting energy" for stability and posture control in simulated lunar gravity. Biomechanics data could influence advanced spacesuit design and planetary habitat design, while workload data will help define oxygen requirements for planetary life support systems.

  1. Origin of Martian Moons from Binary Asteroid Dissociation

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Lyons, Valerie J. (Technical Monitor)

    2001-01-01

    The origin of the Martian moons Deimos and Phobos is controversial. A common hypothesis for their origin is that they are captured asteroids, but the moons show no signs of having been heated by passage through a (hypothetical) thick martian atmosphere, and the mechanism by which an asteroid in solar orbit could shed sufficient orbital energy to be captured into Mars orbit has not been previously elucidated. Since the discovery by the space probe Galileo that the asteroid Ida has a moon 'Dactyl', a significant number of asteroids have been discovered to have smaller asteroids in orbit about them. The existence of asteroid moons provides a mechanism for the capture of the Martian moons (and the small moons of the outer planets). When a binary asteroid makes a close approach to a planet, tidal forces can strip the moon from the asteroid. Depending on the phasing, either or both can then be captured. Clearly, the same process can be used to explain the origin of any of the small moons in the solar system.

  2. Degassing history of Mars from Martian atmosphere samples

    NASA Technical Reports Server (NTRS)

    Rao, A. S. P.

    1988-01-01

    A comparison of the abundances of Ar-40 and He-4 (radiogenic) in various terrestrial planetary atmospheres provides clues to the volcanic and tectonic histories of the planets while the amount of primordial noble gases in the planetary atmospheres provides clues to the quantities of volatile rich materials captured by each planet. The noble gas contents of Mars, Earth, and Venus clearly show that the absolute abundances of isotopes of gases are directly proportional to the amounts of degassed CO2 into the planetary atmosphere. Several basic geological units can be seen on the global geological map of Mars. The enormous size of volcanic and tectonic structures of Mars, despite its smaller size, provide invaluable clues to the degassing history of Mars. Therefore, the collection of samples of Martian atmosphere and soil volatiles is imperative to understand the origin and evolution of the atmosphere and its interaction with the Martian surface. Surface properties of Martian rocks, soils, breccias, and regolith and their chemistry are also generic to any discussion on the origin and evolution of the atmosphere of Mars. The differences in absolute abundances of gases in the planetary atmospheres are amenable to many alternative interpretations. These alternative interpretations can be tested by imposing additional constraints derived from the isotopic results of noble gases in the atmospheres of the planets.

  3. The physics of Martian weather and climate: a review.

    PubMed

    Read, P L; Lewis, S R; Mulholland, D P

    2015-12-01

    The planet Mars hosts an atmosphere that is perhaps the closest in terms of its meteorology and climate to that of the Earth. But Mars differs from Earth in its greater distance from the Sun, its smaller size, its lack of liquid oceans and its thinner atmosphere, composed mainly of CO(2). These factors give Mars a rather different climate to that of the Earth. In this article we review various aspects of the martian climate system from a physicist's viewpoint, focusing on the processes that control the martian environment and comparing these with corresponding processes on Earth. These include the radiative and thermodynamical processes that determine the surface temperature and vertical structure of the atmosphere, the fluid dynamics of its atmospheric motions, and the key cycles of mineral dust and volatile transport. In many ways, the climate of Mars is as complicated and diverse as that of the Earth, with complex nonlinear feedbacks that affect its response to variations in external forcing. Recent work has shown that the martian climate is anything but static, but is almost certainly in a continual state of transient response to slowly varying insolation associated with cyclic variations in its orbit and rotation. We conclude with a discussion of the physical processes underlying these long- term climate variations on Mars, and an overview of some of the most intriguing outstanding problems that should be a focus for future observational and theoretical studies.

  4. Waves in the martian atmosphere: Observations, Theory, and Application

    NASA Astrophysics Data System (ADS)

    Murphy, James

    2001-11-01

    Ongoing spacecraft exploration and numerical model studies indicate the presence in the martian atmosphere of migrating thermal waves with structures extending from the surface to at least 100 kilometers altitude. High frequency atmospheric waves are both a direct (westward travelling) and indirect (eastward travelling) response to the diurnal variations of solar heating and cooling. The eastward travelling waves are the result of longitudinal asymmetries in the thermal forcing, generated by topography and atmospheric dust on Mars. Quantification of these waves offers both a window into the physical state of the martian atmosphere (dust load, temperature structure, wind field structure) as well as a tool by which the state of the martian thermosphere can be ‘predicted’ for spacecraft aerobraking and aerocapture purposes. We will discuss the current theoretical understanding of these wave phenomena, the observational record of the same, and the ongoing employment of this growing understanding in the current aerobraking activities of the Mars ’01 Odyssey orbiter (due to arrive into orbit about Mars on Oct. 24, 2001). This work is funded by NASA’s Mars Data Analysis Program and by the Mars Exploration Office at JPL.

  5. Martian glaciation and the flow of solid CO2

    NASA Technical Reports Server (NTRS)

    Clark, B. R.; Mullin, R. P.

    1976-01-01

    Results are discussed for a series of laboratory deformation experiments that were conducted to determine a flow law for solid CO2 so that a physical basis could be established for considering the possibility of CO2 glaciation in the Martian polar regions. The experimentally determined flow law indicates that (1) the concept of CO2 glacial flow at the Martian poles is not physically unrealistic, (2) the strength of CO2 near its sublimation point is considerably less than the strength of water ice near its melting point, and (3) CO2 is likely to flow over a broad range of temperatures below its melting point. A glacial model for the Martian polar caps is suggested in which CO2-rich layers deposited near the poles flowed outward laterally to relieve high internal shear stresses. It is shown that this model can explain the topography of the polar caps, the uniform layering of the layered deposits, and the general extent of the polar 'sediments'. Some problematic assumptions of the model are noted, including the large amounts of CO2 necessary to move the layered deposits and the need to increase vapor pressure and temperature with depth in the deposits.

  6. Geochemistry of Martian Meteorites and the Petrologic Evolution of Mars

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, D. W.

    2002-01-01

    Mafic igneous rocks serve as probes of the interiors of their parent bodies - the compositions of the magmas contain an imprint of the source region composition and mineralogy, the melting and crystallization processes, and mixing and assimilation. Although complicated by their multifarious history, it is possible to constrain the petrologic evolution of an igneous province through compositional study of the rocks. Incompatible trace elements provide one means of doing this. I will use incompatible element ratios of martian meteorites to constrain the early petrologic evolution of Mars. Incompatible elements are strongly partitioned into the melt phase during igneous processes. The degree of incompatibility will differ depending on the mineral phases in equilibrium with the melt. Most martian meteorites contain some cumulus grains, but nevertheless, incompatible element ratios of bulk meteorites will be close to those of their parent magmas. ALH 84001 is an exception, and it will not be discussed. The martian meteorites will be considered in two groups; a 1.3 Ga group composed of the clinopyroxenites and dunite, and a younger group composed of all others.

  7. The Loss Rate of Ions from the Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Brain, D. A.; McFadden, J. P.; Halekas, J. S.; Connerney, J. E. P.; Bougher, S. W.; Curry, S.; Dong, C.; Dong, Y.; Eparvier, F. G.; Fang, X.; Fortier, K.; Hara, T.; Harada, Y.; Jakosky, B. M.; Lillis, R. J.; Livi, R.; Luhmann, J. G.; Ma, Y.; Modolo, R.; Seki, K.; Thiemann, E.

    2015-12-01

    In November 2014 the MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft began the science phase of its mission to study the upper atmosphere of Mars and its escape to space. The loss of atmospheric particles (in neutral or charged state) to space is thought to have played a role in the evolution of the Martian climate over the past ~4 billion years. Charged particle escape at Mars may be significant due to the absence of a global dynamo magnetic field for most of its history, allowing more direct access of the solar wind to the Martian atmosphere. Among its many measurement capabilities, MAVEN can detect escaping planetary ions with high time cadence and high energy and mass resolution using the STATIC (SupraTheral and Thermal Ion Composition) instrument. We present the results of an effort to compute the escape rate of ions from the Martian atmosphere over MAVEN's primary mission. We statistically map the measured fluxes of planetary ions to various surfaces near Mars, including a closed spherical shell surrounding the planet. We map both incoming and outgoing ion fluxes over different mass and energy ranges, and separate the fluxes by different drivers of escape measured by MAVEN, including solar wind pressure, Extreme Ultraviolet flux, and Interplanetary Magnetic Field strength. We place our results in context with measurements of ion escape made by the Phobos 2 and Mars Express missions, and address the implications for atmospheric loss over the history of the planet.

  8. A model for the origin of Martian polygonal terrain

    NASA Technical Reports Server (NTRS)

    Mcgill, G. E.

    1993-01-01

    Extensive areas of the Martian northern plains in Utopia and Acidalia Planitiae are characterized by 'polygonal terrain.' Polygonal terrain consists of material cut by complex troughs defining a pattern resembling mudcracks, columnar joints, or frost-wedge polygons on the Earth. However, the Martian polygons are orders of magnitude larger than these potential Earth analogs, leading to severe mechanical difficulties for genetic models based on simple analogy arguments. Stratigraphic studies show that the polygonally fractured material in Utopia Planitia was deposited on a land surface with significant topography, including scattered knobs and mesas, fragments of ancient crater rims, and fresh younger craters. Sediments or volcanics deposited over topographically irregular surfaces can experience differential compaction producing drape folds. Bending stresses due to these drape folds would be superposed on the pervasive tensile stresses due to desiccation or cooling, such that the probability of fracturing is enhanced above buried topographic highs and suppressed above buried topographic lows. Thus it was proposed that the scale of the Martian polygons is controlled by the spacing of topographic highs on the buried surface rather than by the physics of the shrinkage process.

  9. High-Resolution Multiple Sulfur Isotope Studies of Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Mojzsis, S. J.

    2000-01-01

    Sensitive, high resolution measurements of S-32, S-31, and S-34 in individual pyrite grains in martian meteorite ALH84001 by an in situ ion microprobe multi-collection technique reveal mass-independent anomalies in Delta.S-33 (Delta.S-33 = delta.S-33 - 0.516delta.S-34) in addition to the lowest 634S found in an extraterrestrial material. Low delta.S-34 values in two pyrite grains intimately associated with carbonate in ALH84001 can be explained by the sensitivity of sulfur to fractionations in the geologic environment. Anomalies in Delta.S-33 recorded in ALH84001 pyrites probably formed by gas-phase reactions in the early martian atmosphere (>4 Ga). The discovery of clearly resolvable Delta-S33 anomalies in 2 of 12 ALH84001 pyrites analyzed in their petrographic context in thin section, is considered strong evidence for crust-atmosphere exchange and the global cycling of volatile sulfur species on early Mars. These results corroborate previous measurements by Farquhar and co-workers who used a different technique that measures that bulk Delta.S-33 values of martian meteorites. These independent techniques, and their results, suggest that sulfur affected by mass-independent fractionation is common on Mars.

  10. Biohazard potential of putative Martian organisms during missions to Mars.

    PubMed

    Warmflash, David; Larios-Sanz, Maia; Jones, Jeffrey; Fox, George E; McKay, David S

    2007-04-01

    Exploration Class missions to Mars will require precautions against potential contamination by any native microorganisms that may be incidentally pathogenic to humans. While the results of NASA's Viking biology experiments of the 1970s have been generally interpreted as inconclusive for surface organisms, and attributed to active but nonbiological chemistries, the possibility of native surface life has never been ruled out completely. It is possible that, prior to the first human landing on Mars, robotic craft and sample return missions will provide enough data to know with certainty whether future human landing sites harbor extant life forms. If native life were found to exist, it would be problematic to determine whether any of its species might present a medical danger to astronauts. Therefore, it will become necessary to assess empirically the risk that the planet contains pathogens based on terrestrial examples of pathogenicity and to take a reasonably cautious approach to biohazard protection. A survey of terrestrial pathogens was conducted with special emphasis on those whose evolution has not depended on the presence of animal hosts. The history of the development and implementation of Apollo anti-contamination protocol and recommendations of the National Research Council's Space Studies Board regarding Mars were reviewed. Organisms can emerge in Nature in the absence of indigenous animal hosts and both infectious and non-infectious human pathogens are therefore theoretically possible on Mars. Although remote, the prospect of Martian surface life, together with the existence of a diversity of routes by which pathogenicity has emerged on Earth, suggests that the probability of human pathogens on Mars, while low, is not zero. Still, since the discovery and study of Martian life can have long-term benefits for humanity, the risk that Martian life might include pathogens should not be an obstacle to human exploration. As a precaution, it is recommended that EVA

  11. Biohazard potential of putative Martian organisms during missions to Mars.

    PubMed

    Warmflash, David; Larios-Sanz, Maia; Jones, Jeffrey; Fox, George E; McKay, David S

    2007-04-01

    Exploration Class missions to Mars will require precautions against potential contamination by any native microorganisms that may be incidentally pathogenic to humans. While the results of NASA's Viking biology experiments of the 1970s have been generally interpreted as inconclusive for surface organisms, and attributed to active but nonbiological chemistries, the possibility of native surface life has never been ruled out completely. It is possible that, prior to the first human landing on Mars, robotic craft and sample return missions will provide enough data to know with certainty whether future human landing sites harbor extant life forms. If native life were found to exist, it would be problematic to determine whether any of its species might present a medical danger to astronauts. Therefore, it will become necessary to assess empirically the risk that the planet contains pathogens based on terrestrial examples of pathogenicity and to take a reasonably cautious approach to biohazard protection. A survey of terrestrial pathogens was conducted with special emphasis on those whose evolution has not depended on the presence of animal hosts. The history of the development and implementation of Apollo anti-contamination protocol and recommendations of the National Research Council's Space Studies Board regarding Mars were reviewed. Organisms can emerge in Nature in the absence of indigenous animal hosts and both infectious and non-infectious human pathogens are therefore theoretically possible on Mars. Although remote, the prospect of Martian surface life, together with the existence of a diversity of routes by which pathogenicity has emerged on Earth, suggests that the probability of human pathogens on Mars, while low, is not zero. Still, since the discovery and study of Martian life can have long-term benefits for humanity, the risk that Martian life might include pathogens should not be an obstacle to human exploration. As a precaution, it is recommended that EVA

  12. The Martian Atmosphere, Climate, and General Circulation Models

    NASA Astrophysics Data System (ADS)

    Richardson, M. I.

    2004-05-01

    Our understanding of the Martian atmosphere, and the embodiment of this understanding in GCM models, sits part way between that of the Earth's atmosphere and that of the other planets in the solar system. Compared to the Earth, it is incomplete even as it applies to certain basic, elementary components and it is studied by a very limited community. Compared to the other planets in the solar system, most elements of the circulation are understood in outline, the data sets are vast and rich, and a number of well-staffed, competing modeling groups exist. Given this ``middle sibling'' status of Martian atmospheric science, an obvious issue arises as to whom it should be compared: Is the paucity of our understanding compared to the Earth motivation for redoubled efforts, or advanced state of knowledge cause to refocus on other planetary bodies? In this presentation, I will review the components of the Martian circulation and the progress that has been made in their understanding through the synthesis of data with GCMs. I will also review the aspects of Martian climate that uniquely influence the atmosphere. These include the lofting of dust by large-scale winds and thermal convection, resulting in a permanent (if varying) dust haze that significantly increases atmospheric temperatures, and occasionally leading to the generation of global dust storms. The spontaneous generation of such storms in a GCM has only very recently been accomplished. The condensation of the major atmospheric constituent (CO2) onto the surface to form massive seasonal ice caps in the frigid polar winter also generates a significant climate signal and a pole-to-pole condensation flow. Finally, Mars possesses an active water cycle with the development of clouds, formation of seasonal water ice deposits, and storage of water in the near-sub surface as adsorbate. The water cycle is fundamentally driven by exchange with a residual water ice cap at the northern (and not the southern) pole. Such

  13. The viability of native microbial communities in martian environment (model)

    NASA Astrophysics Data System (ADS)

    Vorobyova, Elena; Cheptcov, Vladimir; Pavlov, Anatolyi; Vdovina, Mariya; Lomasov, Vladimir

    For today the important direction in astrobiology is the experimental simulation of extraterrestrial habitats with the assessment of survivability of microorganisms in such conditions. A new task is to investigate the resistance of native microbial ecosystems which are well adapted to the environment and develop unique protection mechanisms that enable to ensure biosphere formation. The purpose of this research was to study the viability of microorganisms as well as viability of native microbial communities of arid soils and permafrost under stress conditions simulating space environment and martian regolith environment, estimation of duration of Earth like life in the Martian soil. The experimental data obtained give the proof of the preservation of high population density, biodiversity, and reproduction activity under favorable conditions in the Earth analogues of Martian soil - arid soils (Deserts of Israel and Morocco) and permafrost (East Siberia, Antarctica), after the treatment of samples by ionizing radiation dose up to 100 kGy at the pressure of 1 torr, temperature (- 50oC) and in the presence of perchlorate (5%). It was shown that in simulated conditions close to the parameters of the Martian regolith, the diversity of natural bacterial communities was not decreased, and in some cases the activation of some bacterial populations occurred in situ. Our results allow suggesting that microbial communities like those that inhabit arid and permafrost ecosystems on the Earth, can survive at least 500 thousand years under conditions of near surface layer of the Martian regolith. Extrapolation of the data according to the intensity of ionizing radiation to the open space conditions allows evaluating the potential lifespan of cells inside meteorites as 20-50 thousand years at least. In this work new experimental data have been obtained confirming the occurrence of liquid water and the formation of wet soil layer due to sublimation of ice when the temperature of the

  14. Carbon and Oxygen Stable Isotope Measurements of Martian Atmospheric CO2 by the Phoenix Lander

    NASA Technical Reports Server (NTRS)

    Niles, Paul B.; Boynton, W. V.; Hoffman, J. H.; Ming, D. W.; Hamara, D.

    2010-01-01

    Precise stable isotope measurements of the CO2 in the martian atmosphere have the potential to provide important constraints for our understanding of the history of volatiles, the carbon cycle, current atmospheric processes, and the degree of water/rock interaction on Mars [1]. The isotopic composition of the martian atmosphere has been measured using a number of different methods (Table 1), however a precise value (<1%) has yet to be achieved. Given the elevated Delta(sup 13)C values measured in carbonates in martian meteorites [2-4] it has been proposed that the martian atmosphere was enriched in 13C [8]. This was supported by measurements of trapped CO2 gas in EETA 79001[2] which showed elevated Delta(sup 13)C values (Table 1). More recently, Earth-based spectroscopic measurements of the martian atmosphere have measured the martian CO2 to be depleted in C-13 relative to CO2 in the terrestrial atmosphere[ 7, 9-11]. The Thermal and Evolved Gas Analyzer (TEGA) instrument on the Mars Phoenix Lander [12] included a magnetic-sector mass spectrometer (EGA) [13] which had the goal of measuring the isotopic composition of martian atmospheric CO2 to within 0.5%. The mass spectrometer is a miniature instrument intended to measure both the martian atmosphere as well as gases evolved from heating martian soils.

  15. KGB agents

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    A short story is reported in which the activity of Communist Party of the USSR and secret KGB agents, which were payed by the State, in view of controlling of the conscience of population. The story reffers to the Physics Department of the Moscow University, Planing Institute of the Gosplan of Moldavian S.S.R. and Chishinau Technical University (actually: Technical University of Moldova), where the author has worked during Soviet times. Almost every 6-th citizen in the USSR was engaged in this activity, while actually the former communists rule in the Republic of Moldova.

  16. The potential importance of phosphorus for martian magmatism

    NASA Astrophysics Data System (ADS)

    Toplis, Michael

    2015-04-01

    Magmatic rocks from Mars shows many important compositional differences compared to terrestrial counterparts. For example, one of the most striking features of volcanic rocks from Mars is that they are significantly richer in iron and poorer in silica than lavas produced by partial melting of the Earth's mantle. The iron-rich nature of Martian volcanics has been attributed to a higher FeO content of the Martian mantle [1], while the low silica content has no widely accepted explanation. It is also of note that the SNC meteorites generally show superchondritic Ca/Al, an observation which contrasts with most terrestrial basalts, and which places constraints on the composition of the mantle source which produced the SNC's. In addition to these differences in major-element chemistry, the available analyses of Martian rocks suggest that the sampled silicate portion of Mars is significantly richer in phosphorus than the Earth's crust/ upper mantle. On the other hand, no particular importance has been attached to this observation. It is the aim of this contribution to make the case that this difference may be potentially important. One of the most significant influences of the addition of small amounts of phosphorus to a peridotite assemblage concerns the compositions of liquids produced by partial melting. The presence of phosphorus in a silicate melt is known to dramatically affect silica activity, as elegantly demonstrated by the experimental results of [2]. Using the MELTS thermodynamic calculator [3], it is shown that for a bulk Martian mantle containing ~0.17wt% P2O5 [1], low degree partial melts on Mars will be particularly silica-poor, in contrast to the Earth where the relative absence of P and competing effect of alkalis leads to high silica contents. The difference in silica content between liquids produced from a mantle with 0 and 0.2 wt% P2O5 is predicted to be almost 10wt% SiO2 when the degree of partial melting is 3%, a value more or less independent of

  17. MOURA Martian magnetometer potential for high resolution magnetic mapping

    NASA Astrophysics Data System (ADS)

    Díaz-Michelena, Marina; Kilian, Rolf

    2013-04-01

    Mars Global Surveyor (MGS) mission mapped the magnetic signature all along the Martian globe during its operation between 1996 and 2006. These data shows that Mars does not present an active global magnetic field as the Earth. However, the Martian crust has an overall magnetic signature stronger than the Earth which was inherited from the active magnetic field of the Martian core during its early cooling history. The MGS survey shows plenty of magnetic anomalies located in particular within high lands of its Southern Hemisphere. Several magnetic models have been derived to explain the MGS data considering magnetic dipoles distribution in the Martian crust with moderate to high magnetic intensities and pronounced regional anomalies. However, the origin of major magnetic anomalies remains highly disputed [1]. From the magnetic investigation point of view it would be of major importance to perform near-surface magnetic measurements [2] to compare both surface and in orbit (between 100 and 440 km) data. This would help to comprehend not only the distribution of the magnetic dipoles but also to make progress in the identification of different rock types and understanding of their degree of alteration which could have modified superficial magnetic signatures. In the frame of Finnish-Russian and Spanish MetNet mission, to perform meteorological studies on Martian surface, a miniaturized magnetometer and gradiometer named MOURA was developed with the objective to improve the interpretation of the magnetic anomalies and their origin. In order to test this magnetometer, comparative on Earth magnetic measurements were performed with MOURA and a reference absolute scalar magnetometer (Geometrics 853) in areas with a representative and large variation of magmatic rocks compositions. The final goal is to test the appropriateness of the developed magnetometer for the in situ measurements on Mars. The active continental margin of the Patagonian Andes was used for this case study

  18. The Martian Surface is old and so are Shergottites

    NASA Astrophysics Data System (ADS)

    Bouvier, A.; Blichert-Toft, J.; Vervoort, J. D.; Albarede, F.

    2005-12-01

    We report new Sm-Nd, Lu-Hf, and Pb-Pb mineral and whole-rock (WR) isotope data for the basaltic shergottite (BS) Zagami (Zag), as well as Pb-Pb WR isotope data for the BS Los Angeles (LA). The isotopic analyses were carried out by MC-ICP-MS at ENSL. The Sm-Nd and Lu-Hf data for Zag yield internal isochron ages of 155±9 Ma (MSWD=0.45) and 185±36 Ma (MSWD=1.2), respectively. While these young ages overlap with earlier Rb-Sr, Sm-Nd, and U-Pb ages (2), the Pb-Pb age does not. Our Pb isotope data on Zag and LA lie on the same Pb-Pb array as previous analyses of BS by (1), which, if interpreted as an isochron, indicate an age of ~4 Ga. The range of δ18O (3.9-5.2 permil) observed in shergottites (3, 4) is too broad to be accounted for by igneous processes only and attests to low-T interaction with fluids. The Martian surface appears to be covered with sulfates, while essentially lacking carbonates (5, 6), implying that the surface of Mars was once covered with acidic water bodies of unknown depths (7). An important observation is that apatite is a common phase in Zag and LA, as in all the shergottites (8), and explains why most of the REE, Th, U, and some fraction of Pb can be removed by leaching (9). The main inventory of Pb, however, resides in maskelynite. The Pb isotope data on shergottites, in conjunction with the existing body of geochemical and geophysical evidence, have important implications for the history of the Martian surface and lithosphere. A fundamental problem with the young crystallization ages for the Martian meteorites has been that these ages are difficult to reconcile with the large 182W and 142Nd isotopic anomalies present in these meteorites. On one hand, the anomalies from the extinct radionuclides appear to require a static, non-convecting mantle, whereas widespread volcanism on Mars as young as 150 Ma seems to require an actively convecting mantle. We suggest, based on the Pb isotope systematics of shergottites, that the Martian surface is

  19. Data processing of Martian topographic information obtained from ground-based radar and spectroscopy and from Mariners 6 and 7. Martian topography elevations: Data processing

    NASA Technical Reports Server (NTRS)

    Anderson, K. A.

    1974-01-01

    Papers are presented which were published as a result of a project involving the preparation of a topographical elevation contour map of Mars from all data sources available through 1969, as well as the observation of Mars by spectroscopic methods in 1971 to provide additional pressure data for topographic information. Topics of the papers include: the analysis of large-scale Martian topography variations - data preparation from earth based radar, earth based CO2 spectroscopy, and Mariners 6 and 7 CO2 spectroscopy; the analysis of water content in observed Martian white clouds; and Martian, lunar, and terrestrial crusts - a three-dimensional exercise in comparative geophysics.

  20. Filling agents.

    PubMed

    Glavas, Ioannis P

    2005-06-01

    Injectable fillers have become an important component of minimally invasive facial rejuvenation modalities. Their ease of use, effectiveness, low morbidity, and fast results with minimal downtime are factors that have made them popular among patients. Soft tissue augmentation has evolved to a unique combination of medicine and art. A wide selection of available agents and new products, each one with unique properties, may be used alone or in combination. The physician acquires the tools to rebalance facial characteristics not only by filling wrinkles but also by having the ability to shape the face and restore bony contours and lines. Careful selection of candidates, realistic expectations, and an understanding of the limitations of fillers are crucial for a successful result.