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Sample records for 29th martian day

  1. Opportunity's Travels During its First 205 Martian Days

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This map shows the traverse of NASA's Mars Exploration Rover Opportunity through the rover's 205th martian day, or sol (Aug. 21, 2004). The background image is from the rover's descent imaging camera. Images inset along the route are from Opportunity's navigation camera. Opportunity began its exploration inside 'Eagle' crater near the left edge of the map. Following completion of its study of the outcrop there, it traversed eastward to a small crater ('Fram' crater) before driving southeastward to the rim of 'Endurance' crater. After a survey partly around the south rim of Endurance crater, Opportunity drove inside the southwest rim of Endurance crater and began a systematic study of outcrops exposed on the crater's inner slope.

  2. Spirit's Travels During its First 238 Martian Days

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This map shows the complete traverse of NASA's Mars Exploration Rover Spirit through the rover's 238th martian day, or sol (Sept. 3, 2004). This was shortly before the rover stopped driving for about two weeks while Mars was nearly behind the Sun from Earth's perspective. The background image consists of frames from the Mars Orbiter Camera on NASA's Mars Global Surveyor orbiter. Inset images along the route are from Spirit's navigation camera. From its landing site, Spirit drove up to the rim of 'Bonneville' crater on the far left and to the north rim of 'Missoula' crater. Then it commenced a long drive across the plains, deviating to avoid large hollows. Upon arrival at the base of the 'Columbia Hills,' Spirit drove north for a short distance before beginning its ascent onto the 'West Spur,' where it is currently located. The scale bar at lower left is 500 meters (1,640 feet). North is up.

  3. Sixty-One Martian Days of Weather Monitoring

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Canadian Meteorological Station on NASA's Phoenix Mars Lander tracked some changes in daily weather patterns over the first 61 Martian days of the mission (May 26 to July 22, 2008), a period covering late spring to early summer on northern Mars.

    This summary weather report notes that daily temperature ranges have changed only about 4 Celsius degrees (7 Fahrenheit degrees) since the start of the mission. The average daily high has been minus 30 degrees C (minus 22 degrees F), and the average daily low has been minus 79 degrees C (minus 110 degrees F).

    The mission has been accumulating enough wind data to recognize daily patterns, such as a change in direction between day and night, and to begin analyzing whether the patterns are driven by local factors or larger-scale movement of the atmosphere.

    The air pressure has steadily decreased. Scientists attribute this to a phenomenon on Mars that is not shared by Earth. The south polar cap of carbon dioxide ice grows during the southern winter on Mars, pulling enough carbon dioxide out of the thin atmosphere to cause a seasonal decrease in the amount of atmosphere Mars has. Most of the Martian atmosphere is carbon dioxide. This measurable dip in atmospheric pressure, even near the opposite pole, is a sign of large amounts of carbon dioxide being pulled out of the atmosphere as carbon-dioxide ice accumulates at the south pole.

    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. Chemical interactions between the present-day Martian atmosphere and surface minerals

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald; Fegley, Bruce

    1987-01-01

    Thermochemical and photochemical reactions between surface minerals and present-day atmospheric constituents are predicted to produce microscopic effects on the surfaces of mineral grains. Relevant reactions hypothesized in the literature include conversions of silicates and volcanic glasses to clay minerals, conversion of ferrous to ferric compounds, and formation of carbonates, nitrates, and sulfates. These types of surface-atmosphere interactions are important for addressing issues such as chemical weathering of minerals, biological potential of the surface environment, and atmospheric stability in both present and past Martian epochs. It is emphasized that the product of these reactions will be observable and interpretable on the microscopic surface layers of Martian surface rocks using modern techniques with obvious implications for sample return from Mars. Macroscopic products of chemical weathering reactions in past Martian epochs are also expected in Martian surface material. These products are expected not only as a result of reactions similar to those proceeding today but also due to aqueous reactions in past epochs in which liquid water was putatively present. It may prove very difficult or impossible however to determine definitively from the relic macroscopic product alone either the exact weathering process which led to its formation or the identity of its weathered parent mineral. The enormous advantages of studying Martian chemical weathering by investigating the microscopic products of present-day chemical reactions on sample surfaces are very apparent.

  5. Chemical interactions between the present-day Martian atmosphere and surface minerals: Implications for sample return

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald; Fegley, Bruce

    1988-01-01

    Thermochemical and photochemical reactions between surface minerals and present-day atmospheric constituents are predicted to produce microscopic effects on the surface of mineral grains. Relevant reactions hypothesized in the literature include conversions of silicates and volcanic glasses to clay minerals, conversion of ferrous to ferric compounds, and formation of carbonates, nitrates, and sulfates. These types of surface-atmosphere weathering of minerals, biological potential of the surface environment, and atmospheric stability in both present and past Martian epochs. It is emphasized that the product of these reactions will be observable and interpretable on the microscopic surface layers of Martian surface rocks using modern techniques with obvious implications for sample return from Mars. Macroscopic products of chemical weathering reactions in past Martian epochs are also expected in Martian surface materials. These products are expected not only as a result of reactions similar to those proceeding today but also due to aqueous reactions in past epochs in which liquid water was putatively present. It may prove very difficult or impossible, however, to determine definitively from the relic macroscopic product alone either the exact weathering process which led to its formation of the identity of its weathering parent mineral. The enormous advantages of studying the Martian chemical weathering by investigating the microscopic products of present-day chemical reactions on sample surfaces are very apparent.

  6. The 29th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    Schneider, William C. (Editor)

    1995-01-01

    The proceedings of the 29th Aerospace Mechanisms Symposium, which was hosted by NASA Johnson Space Center and held at the South Shore Harbour Conference Facility on May 17-19, 1995, are reported. Technological areas covered include actuators, aerospace mechanism applications for ground support equipment, lubricants, pointing mechanisms joints, bearings, release devices, booms, robotic mechanisms, and other mechanisms for spacecraft.

  7. Long Day's Drive: An Alternative Paradigm for Martian Robotic Exploration

    NASA Technical Reports Server (NTRS)

    Sims, M. H.; McKay, C. P.

    2003-01-01

    Long Day's Drive (LLD) will investigate the north polar layered deposits (PLD). The overarching science rationale for LDD is the belief that the PLD preserve within their stratigraphy an interpretable record of recent climate and geologic history for Mars. Our primary goal is to obtain data that can provide a basis for interpreting that record. In addition, we will test the hypothesis that the ice of the PLD contains organics at higher concentrations than the aeolian dust sampled at the two Viking sites. Finally, we seek to contribute to the understanding of Mars' total volatile inventory by detailed determination of the ice content of the PLD over the traverse.

  8. Adaptation of an Antarctic lichen to Martian niche conditions can occur within 34 days

    NASA Astrophysics Data System (ADS)

    de Vera, Jean-Pierre; Schulze-Makuch, Dirk; Khan, Afshin; Lorek, Andreas; Koncz, Alexander; Möhlmann, Diedrich; Spohn, Tilman

    2014-08-01

    Stresses occurring on the Martian surface were simulated in a Mars Simulation Chamber (MSC) and included high UV fluxes (Zarnecki and Catling, 2002), low temperatures, low water activity, high atmospheric CO2 concentrations, and an atmospheric pressure of about 800 Pa (Kasting, 1991; Head et al., 2003). The lichen Pleopsidium chlorophanum is an extremophile that lives in very cold, dry, high-altitude habitats, which are Earth's best approximation of the Martian surface. Samples with P. chlorophanum were exposed uninterruptedly to simulated conditions of the unprotected Martian surface (i.e. 6344 kJ m-2) and protected niche conditions (269 kJ m-2) for 34 days. Under unprotected Martian surface conditions the fungal symbiont decreases its metabolic activity and it was unclear if the algal symbiont of the lichen was still actively photosynthesizing. However, under "protected site" conditions, the entire lichen not only survived and remained photosynthetically active, it even adapted physiologically by increasing its photosynthetic activity over 34 days.

  9. Zonal Wave Number 2 Rossby Wave (3.5-day oscillation) Over The Martian Lower Atmosphere

    NASA Astrophysics Data System (ADS)

    Ghosh, P.; Thokuluwa, R. K.

    2013-12-01

    Over the Mars, height (800-50 Pascal pressure coordinate) profiles of temperature (K), measured by radio occultation technique during the MGS (Mars Global Surveyor) mission, obtained for the period of 1-10 January 2006 at the Martian latitude of ~63N in almost all the longitudes are analyzed to study the characteristics of the 3.5-day oscillation. To avoid significant data gaps in a particular longitude sector, we selected a set of 7 Mars longitude regions with ranges of 0-30E, 35-60E, 65-95E, 190-230E, 250-280E, 290-320E, and 325-360E to study the global characteristics of the 3.5-day oscillation. The 3.5-day oscillation is not selected as a-priori but observed as a most significant oscillation during this period of 1-10 January 2006. It is observed that in the longitude of 0-30E, the 3.5-day oscillation shows statistically significant power (above the 95% confidence level white noise) from the lowest height (800 Pascal, 8 hPa) itself and up to the height of 450 Pascal level with the maximum power of ~130 K^2 at the 600 & 650 Pascal levels. It started to grow from the power of ~ 50 K^2 at the lowest height of 800 Pascal level and reached the maximum power in the height of 600-650 Pascal level and then it started to get lessened monotonously up to the height of 450 Pascal level where its power is ~ 20 K^2. Beyond this height and up to the height of 50 Pascal level, the wave amplitude is below the white noise level. As the phase of the wave is almost constant at all the height levels, it seems that the observed 3.5-day oscillation is a stationary wave with respect to the height. In the 35-60 E longitude sector, the vertical structure of the 3.5-day oscillation is similar to what observed for the 0-30 E longitude region but the power is statistically insignificant at all the heights. However in the 65-95E longitude sector, the wave grows from the lowest level (70 K^2) of 800 Pascal to its maximum power of 280 K^2 in the height of 700 Pascal level and then it started

  10. Pulmonary toxicity of simulated lunar and Martian dusts in mice: I. Histopathology 7 and 90 days after intratracheal instillation

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-Wing; James, John T.; McCluskey, Richard; Cowper, Shawn; Balis, John; Muro-Cacho, Carlos

    2002-01-01

    NASA is contemplating sending humans to Mars and to the moon for further exploration. Volcanic ashes from Arizona and Hawaii with mineral properties similar to those of lunar and Martian soils, respectively, are used to simulate lunar and Martian environments for instrument testing. Martian soil is highly oxidative; this property is not found in Earth's volcanic ashes. NASA is concerned about the health risk from potential exposure of workers in the test facilities. Fine lunar soil simulant (LSS), Martian soil simulant (MSS), titanium dioxide, or quartz in saline was intratracheally instilled into groups of 4 mice (C57BL/6J) at 0.1 mg/mouse (low dose, LD) or 1 mg/mouse (high dose, HD). Separate groups of mice were exposed to ozone (0.5 ppm for 3 h) prior to MSS instillation. Lungs were harvested for histopathological examination 7 or 90 days after the single dust treatment. The lungs of the LSS-LD groups showed no evidence of inflammation, edema, or fibrosis; clumps of particles and an increased number of macrophages were visible after 7 days but not 90 days. In the LSS-HD-7d group, the lungs showed mild to moderate alveolitis, and perivascular and peribronchiolar inflammation. The LSS-HD-90d group showed signs of mild chronic pulmonary inflammation, septal thickening, and some fibrosis. Foci of particle-laden macrophages (PLMs) were still visible. Lung lesions in the MSS-LD-7d group were similar to those observed in the LSS-HD-7d group. The MSS-LD-90d group had PLMs and scattered foci of mild fibrosis in the lungs. The MSS-HD-7d group showed large foci of PLMs, intra-alveolar debris, mild-to-moderate focal alveolitis, and perivascular and peribronchiolar inflammation. The MSS-HD-90d group showed focal chronic mild-to-moderate alveolitis and fibrosis. The findings in the O(3)-MSS-HD-90d group included widespread intra-alveolar debris, focal moderate alveolitis, and fibrosis. Lung lesions in the MSS groups were more severe with the ozone pretreatment. The effects of

  11. They're Alive! Present-Day Evolution of Martian Dunes

    NASA Technical Reports Server (NTRS)

    Diniega, S.; Bridges, N.; Hansen, C.

    2011-01-01

    The sharp brinks and margins, smooth and steep lee slopes, and lack of superimposed landforms (such as small impact craters) on many Martian sand dunes suggests that these features are geologically young clean brinks and smooth/steep lee slopes (HiRISE image PSP_010413_1920; 20 deg N,79 deg E; image widthis about 500m).Within the last decade, and often primarily through the detailed inspection of high-resolution (HiRISE) images, we have finally found clear evidence that many dunes of Mars are active -- through both aeolian and seasonal (frost) processes. However, it is yet unclear if active dune formation does occur or if we are observing surficial modification of dunes which formed under different climate conditions.

  12. 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.

  13. Chaparrastique (San Mighel) Volcano Eruptions since Dec. 29th, 2013, El Salvador

    NASA Astrophysics Data System (ADS)

    Martinez-Hackert, B.; Bajo, J. V.; Escobar, D.; Gutierrez, E.

    2015-12-01

    The December 29th, 2013 eruption of Chaparrastique (San Miguel) volcano in El Salvador came as a surprise and was the first of several small eruptions in the past two years. They came after many years of preceeding earthquake swarms and significant degassing. Being the second volcano to erupt in El Salvador in less than ten years, it caused grave concern for the population of the country. Although they were not large eruptions (VEI 2), the materials were widespread and caused deposits of volcanic tephra as far at the capital San Salvador and closed the airports in the vecinity for a couple of days. This is a summary of the research, mitigation and services that were done days after the first eruption on December 29, 2013 and the follwing months. In conjunction with the team of the Direccion General del Observatorio Ambiental from the Ministerio de Medio Ambiente y Recursos Naturales possible first response strategies were discussed and decided to obtain results that could be quickly put in place to mitigate and decide on actions such as evacuations or relocations of people living in volcano related high-risk hazard areas. Collection of samples, mapping and measurements of the volcanic tephra in the field together with Digital Globe and areal photography after the event, allowed identification of four different volcanic products that can be correlated to the opening of the vent and ending in the eruption of juvenile materials of basaltic to trachybasaltic composition, and the production of a lahar hazard map based on LaharZ.

  14. 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.

  15. 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.

  16. EDITORIAL: The 29th International Conference on Phenomena in Ionized Gases The 29th International Conference on Phenomena in Ionized Gases

    NASA Astrophysics Data System (ADS)

    de Urquijo, J.

    2010-06-01

    The 29th International Conference on Phenomena in Ionized Gases (ICPIG) was held in Cancún, Mexico, on 12-17 July, 2009, under the sponsorship of the Universidad Nacional Autónoma de Mexico, UNAM, the Universidad Autónoma Metropolitana, UAM, and the International Union of Pure and Applied Physics (IUPAP). ICPIG, founded in 1953, has since been held biennally, and nowadays it covers both fundamental and applied research in all areas of low-temperature plasmas, including those related to the cold plasma in fusion devices. ICPIG fosters interdisciplinary research and interchange between different communities. The conference was attended by scientists from 33 countries. The scientific programme of ICPIG 2009 consisted of 10 General Invited and 24 Topical Lectures, covering all major topics of ICPIG. All speakers were invited to submit peer-reviewed articles based on their lectures for this special issue of Plasma Sources Science and Technology, either as reviews or original work. This special issue contains the papers of most of these talks, covering timely and key issues on elementary processes and fundamental data, plasma wall interactions, including those related to the low-temperature plasma in fusion devices. Several interesting papers were dedicated to plasma modelling, simulation and diagnostics. Important contributions to this issue deal with natural plasmas, low- and atmospheric-pressure plasmas, microplasmas and high-frequency plasmas. Almost half of the contributed papers in this issue are dedicated to applications dealing with plasmas for nanotechnology, plasma sources of various kinds, and other uses of plasmas in particle detection and mass spectrometry. Two workshops were organized. The first reviewed the state of the art on our knowledge of electron, positron and ion interaction processes in gases, with an emphasis on charged particle transport and reactions in electric and magnetic fields, measurement and calculation of cross sections and swarm

  17. Martian surface

    SciTech Connect

    Carr, M.H.

    1987-03-01

    The surface of Mars is characterized on the basis of reformatted Viking remote-sensing data, summarizing results published during the period 1983-1986. Topics examined include impact craters, ridges and faults, volcanic studies (modeling of surface effects on volcanic activity, description and interpretation of volcanic features, and calculations on lava-ice interactions), the role of liquid water on Mars, evidence for abundant ground ice at high latitudes, water-cycle modeling, and the composition and dynamics of Martian dust.

  18. The Campaign for the Occultation of UCAC4-347-165728 (R=12m2) by Pluto on June 29th, 2015

    NASA Astrophysics Data System (ADS)

    Beisker, W.; Sicardy, B.; Berard, D.; Meza, E.; Herald, D.; Gault, D.; Talbot, J.; Bode, H.-J.; Braga-Ribas, F.; Barry, T.; Broughton, J.; Hanna, W.; Bradshaw, J.; Kerr, S.; Pavlov, H.

    2015-10-01

    The occultation of UCAC4-347-165728 (R=12m2)on the 29th of June 2015 by Pluto is the last important occultation by Pluto before the New Horizons flyby 15 days later. Therefore it is a great opportunity to measure details of Pluto's atmosphere from Earth at the same time as the "on-site" determination. Observations from mobile stations and from certain fixed site observatories are planned in an international campaign in Australia and New Zealand. The telescopes will be equipped with EMCCD or CCD cameras to record a frame sequence linked to the exact timing by GPS. With high resolution astrometry in the months and weeks before the event, we intend to define the central line of the occultation so accurate that a positioning of instruments in close proximity of the central line is possible. - First results of the campaign will be presented in this report.

  19. Proceedings of the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    SciTech Connect

    Wetovsky, Marvin A.; Benson, Jody; Patterson, Eileen F.

    2007-09-25

    These proceedings contain papers prepared for the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 25-27 September, 2007 in Denver, Colorado. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  20. Martian Biosignatures: Tantalizing Evidence Within Martian Meteorites

    NASA Astrophysics Data System (ADS)

    Gibson, E. K.; Thomas-Keprta, K. L.; Clemett, S. J.; McKay, D. S.

    2016-05-01

    Several of the martian meteorites offer a unique opportunity to study possible biosignatures over the history of Mars. Reduced carbon components have been found within the pre-terrestrial aqueous alteration phases (iddingsite) of martian meteorites.

  1. 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.

  2. 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

  3. Martian Infotech

    NASA Technical Reports Server (NTRS)

    Covault, Craig

    2005-01-01

    The U.S. is beginning an $800-million project to create an information technology infrastructure at Mars. This will be essentially a Martian internet where robotic spacecraft will conduct high-data-rate exchanges between themselves and with their Earth-based teams. The objective is to better control increasingly ambitious robotic missions and to return more imagery and data from those flights for faster distribution to the science community and public. The focal point will be the Mars Telecommunication Orbiter (MTO), a Mars orbiting communications satellite already approved and funded by Congress for launch to the red planet in 2009.MTO's advanced operational microwave capability should be able to relay to Earth magnitudes more information than current spacecraft, as well as near real-time images from Nasa's next generation of rovers, also set for launch in 2009.

  4. Rumours about the Po Valley earthquakes of 20th and 29th May 2012

    NASA Astrophysics Data System (ADS)

    La Longa, Federica; Crescimbene, Massimo; Camassi, Romano; Nostro, Concetta

    2013-04-01

    The history of rumours is as old as human history. Even in remote antiquity, rumours, gossip and hoax were always in circulation - in good or bad faith - to influence human affairs. Today with the development of mass media, rise of the internet and social networks, rumours are ubiquitous. The earthquakes, because of their characteristics of strong emotional impact and unpredictability, are among the natural events that more cause the birth and the spread of rumours. For this reason earthquakes that occurred in the Po valley the 20th and 29th May 2012 generated and still continue to generate a wide variety of rumours regarding issues related to the earthquake, its effects, the possible causes, future predictions. For this reason, as occurred during the L'Aquila earthquake sequence in 2009, following the events of May 2012 in Emilia Romagna was created a complex initiative training and information that at various stages between May and September 2012, involved population, partly present in the camp, and then the school staff of the municipalities affected by the earthquake. This experience has been organized and managed by the Department of Civil Protection (DPC), the National Institute of Geophysics and Volcanology (INGV), the Emilia Romagna region in collaboration with the Network of University Laboratories for Earthquake Engineering (RELUIS), the Health Service Emilia Romagna Regional and voluntary organizations of civil protection in the area. Within this initiative, in the period June-September 2012 were collected and catalogued over 240 rumours. In this work rumours of the Po Valley are studied in their specific characteristics and strategies and methods to fight them are also discussed. This work of collection and discussion of the rumours was particularly important to promote good communication strategies and to fight the spreading of the rumours. Only in this way it was possible to create a full intervention able to supporting both the local institutions and

  5. Day-side ionospheric photoelectrons observed by MAVEN-SWEA at low altitudes and high solar zenith angles on the Martian night-side

    NASA Astrophysics Data System (ADS)

    Xu, S.; Mitchell, D. L.; Liemohn, M. W.; Dong, C.; Bougher, S. W.; Fillingim, M. O.; McFadden, J. P.; Mazelle, C. X.; Connerney, J. E. P.

    2015-12-01

    Crustal magnetic fields in the northern hemisphere of Mars are generally much weaker than those in the south (Connerney et al. 2005). Over two large regions, Utopia Planitia and the Tharsis rise, the observed magnetic field at 400 km altitude is thought to be dominated by fields induced by the solar wind interaction, although the draping pattern is asymmetric and may be influenced by the presence of crustal sources far from the spacecraft (Brain et al., 2006). The MAVEN mission (Jakosky et al. 2015) provides a comprehensive set of plasma and magnetic field observations to altitudes as low as ~150 km (~120 km during "deep dips") and over a wide range of local times and solar zenith angles. From 12/1/2014 to 2/15/2015, when periapsis was at high northern latitudes, the Solar Wind Electron Analyzer (SWEA) observed ionospheric photoelectrons with energies from 3 to 500 eV at low altitudes (140-200 km) and high solar zenith angles (120-145 deg) on ~35% of the orbits. Since this electron population is unambiguously produced in the dayside ionosphere, these observations demonstrate that the deep Martian nightside is at times magnetically connected to the sunlit hemisphere. We investigated the occurrence rate of ionospheric photoelectrons as a function of altitude, solar zenith angle, and magnetic field orientation, and found that photoelectrons are more likely to be observed at low altitudes and high solar zenith angles when the local field is more vertically oriented. This implies that the magnetic field extends to high altitudes between the night hemisphere, where photoelectrons are observed, and the source region in the dayside ionosphere, thus avoiding significant attenuation in transit. The BATSRUS Mars multi-fluid MHD model (Dong et al., 2014) suggests the presence of closed crustal magnetic field lines over the northern hemisphere that straddle the terminator and extend to high SZA. Simulations with the SuperThermal Electron Transport (STET) model (Xu and Liemohn

  6. 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.

  7. 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.

  8. 2nd International Salzburg Conference on Neurorecovery (ISCN 2013) Salzburg/ Austria | November 28th - 29th, 2013

    PubMed Central

    Brainin, M; Muresanu, D; Slavoaca, D

    2014-01-01

    The 2nd International Salzburg Conference on Neurorecovery was held on the 28th and 29th of November, 2013, in Salzburg, one of the most beautiful cities in Austria, which is well known for its rich cultural heritage, world-famous music and beautiful surrounding landscapes. The aim of the conference was to discuss the progress in the field of neurorecovery. The conference brought together internationally renowned scientists and clinicians, who described the clinical and therapeutic relevance of translational research and its applications in neurorehabilitation. PMID:25713602

  9. Sampling Martian Soil

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Scientists were using the Moessbauer spectrometer on NASA's Mars Exploration Rover Spirit when something unexpected happened. The instrument's contact ring had been placed onto the ground as a reference point for placement of another instrument, the alpha particle X-ray spectrometer, for analyzing the soil. After Spirit removed the Moessbauer from the target, the rover's microscopic imager revealed a gap in the imprint left behind in the soil. The gap, about a centimeter wide (less than half an inch), is visible on the left side of this mosaic of images. Scientists concluded that a small chunk of soil probably adhered to the contact ring on the front surface of the Moessbauer. Before anyone saw that soil may have adhered to the Moessbauer, that instrument was placed to analyze martian dust collected by a magnet on the rover. The team plans to take images to see if any soil is still attached to the Moessbauer. Spirit took these images on the rover's 240th martian day, or sol (Sept. 4, 2004).

  10. Atmospheric concentrations, sources and gas-particle partitioning of PAHs in Beijing after the 29th Olympic Games.

    PubMed

    Ma, Wan-Li; Sun, De-Zhi; Shen, Wei-Guo; Yang, Meng; Qi, Hong; Liu, Li-Yan; Shen, Ji-Min; Li, Yi-Fan

    2011-07-01

    A comprehensive sampling campaign was carried out to study atmospheric concentration of polycyclic aromatic hydrocarbons (PAHs) in Beijing and to evaluate the effectiveness of source control strategies in reducing PAHs pollution after the 29th Olympic Games. The sub-cooled liquid vapor pressure (logP(L)(o))-based model and octanol-air partition coefficient (K(oa))-based model were applied based on each seasonal dateset. Regression analysis among log K(P), logP(L)(o) and log K(oa) exhibited high significant correlations for four seasons. Source factors were identified by principle component analysis and contributions were further estimated by multiple linear regression. Pyrogenic sources and coke oven emission were identified as major sources for both the non-heating and heating seasons. As compared with literatures, the mean PAH concentrations before and after the 29th Olympic Games were reduced by more than 60%, indicating that the source control measures were effective for reducing PAHs pollution in Beijing. PMID:21497969

  11. 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.

  12. Southwest Park and Recreation Training Institute Proceedings (29th, Kingston, Oklahoma, February 5-8, 1984).

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Dept. of Park Administration and Landscape Architecture.

    After presenting introductory material about the Institute and its participants, this document offers brief summaries of workshops held at this conference. Workshop topics were: (1) solar energy; (2) nonverbal communication; (3) land acquisition; (4) employee orientation and counseling; (5) neighborhood parks; (6) Arbor Day; (7) trees in the urban…

  13. Proceedings of the Conference of the International Group for the Psychology of Mathematics Education (29th, Melbourne, Australia, July 10-15, 2005). Volume 2

    ERIC Educational Resources Information Center

    Chick, Helen L., Ed.; Vincent, Jill L., Ed.

    2005-01-01

    This document contains the second volume of the proceedings of the 29th Conference of the International Group for the Psychology of Mathematics Education. Conference papers are centered around the theme of "Learners and Learning Environments." This volume features 43 research reports by presenters with last names beginning between Adl and Fre: (1)…

  14. Proceedings of the Conference of the International Group for the Psychology of Mathematics Education (29th, Melbourne, Australia, July 10-15, 2005). Volume 3

    ERIC Educational Resources Information Center

    Chick, Helen L., Ed.; Vincent, Jill L., Ed.

    2005-01-01

    The third volume of the 29th annual conference of the International Group for the Psychology of Mathematics Education contains full research report papers. Papers include: (1) Students' Use of ICT Tools: Choices and Reasons (Anne Berit Fuglestad); (2) Interaction of Modalities in Cabri: A Case Study (Fulvia Furinghetti, Francesca Morselli, and…

  15. Proceedings of the Conference of the International Group for the Psychology of Mathematics Education (29th, Melbourne, Australia, July 10-15, 2005). Volume 4

    ERIC Educational Resources Information Center

    Chick, Helen L., Ed.; Vincent, Jill L., Ed.

    2005-01-01

    This document is the fourth volume of the proceedings of the 29th Conference of the International Group for the Psychology of Mathematics Education. Conference papers are centered around the theme of "Learners and Learning Environments." This volume features 42 research reports by presenters with last names beginning between Mul and Wu: (1) Case…

  16. Proceedings of the Conference of the International Group for the Psychology of Mathematics Education (29th, Melbourne, Australia, July 10-15, 2005). Volume 1

    ERIC Educational Resources Information Center

    Chick, Helen L., Ed.; Vincent, Jill L., Ed.

    2005-01-01

    The first volume of the 29th annual conference of the International Group for the Psychology of Mathematics Education contains plenary lecture and research forum papers as listed below. Short oral communications papers, poster presentations, brief summaries of discussion groups, and working sessions are also included in the volume. The plenary…

  17. Martian Surface after Phoenix's Conductivity Measurements

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Phoenix Mars Lander's Robotic Arm Camera took this image on Sol 71 (August 6, 2008), the 71st Martian day after landing. The shadow shows the outline of Phoenix's Thermal and Electrical Conductivity Probe, or TECP. The holes seen in the Martian surface were made by this instrument to measure the soil's conductivity. A fork-like probe inserted into the soil checks how well heat and electricity move through the soil from one prong to another.

    The measurements completed Wednesday ran from the afternoon of Phoenix's 70th Martian day, or sol, to the morning of Sol 71.

    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. 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.

  19. Photovoltaic arrays for Martian surface power

    NASA Technical Reports Server (NTRS)

    Appelbaum, Joseph; Landis, Geoffrey 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 on 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.

  20. 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.

  1. 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.

  2. Martian Soil Inside Phoenix's Robotic Arm Scoop

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image from NASA's Phoenix Mars Lander's Robotic Arm Camera (RAC) shows material from the Martian surface captured by the Robotic Arm (RA) scoop during its first test dig and dump on the seventh Martian day of the mission, or Sol 7 (June 1, 2008). The test sample shown was taken from the digging area informally known as 'Knave of Hearts.'

    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. Martian Surface as Seen by Phoenix

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This colorglyph, acquired by NASA's Phoenix Lander's Surface Stereo Imager on Sol 8, the eighth Martian day of the mission (June 2, 2008), shows a stereoscopic 3D view of the Martian surface near the lander. This area is part of Phoenix's workplace and is informally called 'Wonderland.'

    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. 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

  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. Dating of Martian Meteorites: Characterization of Luminescence from a Martian Soil Simulant and Martian Meteorites

    NASA Astrophysics Data System (ADS)

    Banerjee, D.; Blair, M.; Sears, D. W. G.; McKeever, S. W. S.

    2002-03-01

    This paper characterizes the thermoluminescence and optically stimulated luminescence signals from polymineral fine-grains of a Martian soil simulant JSC Mars-1, and the bulk fraction of an SNC Martian meteorite ALH 77005,74.

  8. Exploring for Martian Life

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    During the next decade, robotic field science will play an essential role in advancing our understanding of Martian history. Specifically, capable rovers are needed to survey a broad range of Martian rock types for in situ chemistry and mineralogy as a basis for interpreting globally-distributed data obtained from orbit. The relationship between orbital and landed science will be fundamental in selecting a landing site for future missions aimed at probing the ancient rock record for evidence of: (1) past life or prebiotic chemistry; (2) the climate and volatile history of Mars; and (3) candidate materials for in situ resource utilization.

  9. Martian sedimentary deposits

    NASA Technical Reports Server (NTRS)

    Dehon, Rene

    1992-01-01

    The objectives are characterization of flow through outflow channels, sedimentation associated with Martian outflow systems, and documentation of Martian lakes. Over the period of the grant much, but not all, of the study centered on the Maja Valles outflow. Maja served as an example in which the effects of multiple channel routing and ponding could be studied. Maja Valles also served as the test case for calculating flow through an outflow system. Applying the lessons learned in Maja Valles and comparisons and contrast required a scrutiny of other channels.

  10. 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.

  11. Sampling Martian Soil (3-D)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    Scientists were using the Moessbauer spectrometer on NASA's Mars Exploration Rover Spirit when something unexpected happened. The instrument's contact ring had been placed onto the ground as a reference point for placement of another instrument, the alpha particle X-ray spectrometer, for analyzing the soil. After Spirit removed the Moessbauer from the target, the rover's microscopic imager revealed a gap in the imprint left behind in the soil. The gap, about a centimeter wide (less than half an inch), is visible on the left side of this stereo view. Scientists concluded that a small chunk of soil probably adhered to the contact ring on the front surface of the Moessbauer. Before anyone saw that soil may have adhered to the Moessbauer, that instrument was placed to analyze martian dust collected by a magnet on the rover. The team plans to take images to see if any soil is still attached to the Moessbauer. Spirit took these images on the rover's 240th martian day, or sol (Sept. 4, 2004).

    Figure 1 is the left-eye view of a stereo pair and Figure 2 is the right-eye view of a stereo pair.

  12. 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.

  13. Survival of microorganisms in smectite clays: implications for Martian exobiology.

    PubMed

    Moll, D M; Vestal, J R

    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 Bacillius 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. PMID:11539360

  14. 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.

  15. Martian soil component in impact glasses in a Martian meteorite

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Borg, L. E.; McKay, D. S.; Wentworth, S. J.

    1999-01-01

    Chemical compositions of impact melt glass veins, called Lithology C (Lith C) in Martian meteorite EET79001 were determined by electron microprobe analysis. A large enrichment of S, and significant enrichments of Al, Ca, and Na were observed in Lith C glass compared to Lithology A (Lith A). The S enrichment is due to mixing of plagioclase- enriched Lith A material with Martian soil, either prior to or during impact on Mars. A mixture of 87% Lith A, 7% plagioclase, and 6% Martian soil reproduces the average elemental abundances observed in Lith C. Shock melting of such a mixture of plagioclase-enriched, fine-grained Lith A host rock and Martian soil could yield large excesses of S (observed in this study) and Martian atmospheric noble gases (found by Bogard et al., 1983) in Lith C. These mixing proportions can be used to constrain the elemental abundance of phosphorus in Martian soil.

  16. 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.

  17. 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

  18. 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.

  19. Exploring for Martian Life

    NASA Astrophysics Data System (ADS)

    Farmer, Jack D.

    1997-04-01

    During the coming decade, robotic field science will play a fundamental role in advancing our understanding of the history of Mars. In particular, capable rovers are needed to survey a broad array of Martian rock types for in situ mineralogy and chemistry as a basis for interpreting globally-distributed remote sensing data obtained from orbit. The interplay between orbital and landed science will be fundamental in selecting sites for future missions aimed at exploring the ancient rock record for evidence of A) past life or prebiotic chemistry, B) the volatile and climate history of Mars, and C) materials for in situ resource utilization. The recent suggestion of evidence for life in the Martian meteorite, ALH84001 (McKay, D.S., E.K. Gibson, K.L. Thomas-Keprta, H. Vali, C.S. Romanek, S.J. Clemett, X.D.F. Chillier, C.R. Maechling, R.N. Zare. 1996. Search for past life on Mars: Possible relic biogenic activity in Martian meteorite ALH84001. Science) 273, 924-930has placed Exobiology in a more central position in the Mars exploration (The Search for Evidence of Life on Mars. Unpublished report, Mars Expeditions Strategy Group, 1996.)

  20. 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

  1. The investigation of ionospheric response to total eclipses on 29th March, 2006 and on 20th March, 2015 based on HF oblique sounding data

    NASA Astrophysics Data System (ADS)

    Vertogradov, G. G.; Vertogradova, E. G.

    2016-09-01

    The investigation of ionosphere response to solar eclipses was carried out. Maximum observable frequencies were analyzed during two eclipses on 29th March, 2006 and on 20th March, 2015 on several oblique sounding paths which were within the range of solar flux obscuration. The model describing local changes in the ionosphere, caused by the obscuration of solar flux during eclipse, is suggested. The computer simulation of HF radiowave propagation during the eclipses was carried out on the basis of this model, while quiet ionosphere was described by IRI-2012 model. It is shown that this approach gives adequate description of HF channel during eclipses for all propagation paths under consideration while the parameters of the model were the same for all paths. As the result of computer simulation time delays of ionosperic responses during eclipses were obtained (~1800-2000 s). It was found that maximum depletion of electron concentration reached 85% in D-region for both eclipses. The electron density depletions at height of F2-peak were 48% and 34% for eclipse on 29th March, 2006 and on 20th March, 2015 respectively.

  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. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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).

  8. 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

  9. 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.

  10. 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.

  11. Web life: Be A Martian

    NASA Astrophysics Data System (ADS)

    2011-09-01

    this month's Weblife concentrates on the Be A Martian portal - a rich but manageably sized corner of the NASA site that allows both "Martian citizens" (registered users, in other words) and "anonymous tourists" to explore data and images collected by Mars-bound spacecraft.

  12. 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.

  13. The Martian Oasis Detector

    NASA Astrophysics Data System (ADS)

    Smith, P. H.; tomasko, M. G.; McEwen, A.; Rice, J.

    2000-07-01

    The next phase of unmanned Mars missions paves the way for astronauts to land on the surface of Mars. There are lessons to be learned from the unmanned precursor missions to the Moon and the Apollo lunar surface expeditions. These unmanned missions (Ranger, Lunar Orbiter, and Surveyor) provided the following valuable information, useful from both a scientific and engineering perspective, which was required to prepare the way for the manned exploration of the lunar surface: (1) high resolution imagery instrumental to Apollo landing site selection also tremendously advanced the state of Nearside and Farside regional geology; (2) demonstrated precision landing (less than two kilometers from target) and soft landing capability; (3) established that the surface had sufficient bearing strength to support a spacecraft; and (4) examination of the chemical composition and mechanical properties of the surface. The search for extinct or extant life on Mars will follow the water. However, geomorphic studies have shown that Mars has had liquid water on its surface throughout its geologic history. A cornucopia of potential landing sites with water histories (lakes, floodplains, oceans, deltas, hydrothermal regions) presently exist. How will we narrow down site selection and increase the likelihood of finding the signs of life? One way to do this is to identify 'Martian oases.' It is known that the Martian surface is often highly fractured and some areas have karst structures that support underground caves. Much of the water that formed the channels and valley networks is thought to be frozen underground. All that is needed to create the potential for liquid water is a near surface source of heat; recent lava flows and Martian meteorites attest to the potential for volcanic activity. If we can locate even one spot where fracturing, ice, and underground heat are co-located then we have the potential for an oasis. Such a discovery could truly excite the imaginations of both the

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 75 FR 62131 - Filing Dates for the New York Special Election in the 29th Congressional District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... a 30-day Post-General Report on December 2, 2010. (See chart below for the closing date for each... 2010 and January 2011. (See chart below for the closing date for each report). Unauthorized Committees... chart below for the closing date for each report). Committees filing monthly that make contributions...

  20. 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.

  1. 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).

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Martian atmospheric radiation budget

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1994-01-01

    A computer model is used to study the radiative transfer of the martian winter-polar atmosphere. Solar heating at winter-polar latitudes is provided predominately by dust. For normal, low-dust conditions, CO2 provides almost as much heating as dust. Most heating by CO2 in the winter polar atmosphere is provided by the 2.7 micron band between 10 km and 30 km altitude, and by the 2.0 micron band below 10 km. The weak 1.3 micron band provides some significant heating near the surface. The minor CO2 bands at 1.4, 1.6, 4.8 and 5.2 micron are all optically thin, and produce negligible heating. O3 provides less than 10 percent of the total heating. Atmospheric cooling is predominantly thermal emission by dust, although CO2 15 micron band emission is important above 20 km altitude.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. Relative chronology of Martian volcanoes

    NASA Technical Reports Server (NTRS)

    Landheim, R.; Barlow, N. G.

    1991-01-01

    Impact cratering is one of the major geological processes that has affected the Martian surface throughout the planet's history. The frequency of craters within particular size ranges provides information about the formation ages and obliterative episodes of Martian geologic units. The Barlow chronology was extended by measuring small craters on the volcanoes and a number of standard terrain units. Inclusions of smaller craters in units previously analyzed by Barlow allowed for a more direct comparison between the size-frequency distribution data for volcanoes and established chronology. During this study, 11,486 craters were mapped and identified in the 1.5 to 8 km diameter range in selected regions of Mars. The results are summarized in this three page report and give a more precise estimate of the relative chronology of the Martian volcanoes. Also, the results of this study lend further support to the increasing evidence that volcanism has been a dominant geologic force throughout Martian history.

  14. 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.

  15. Lidar Measurements of Snow Falling from Martian Clouds

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Canadian-built lidar aboard NASA's Phoenix Mars Lander produced this graphic of a profile of a Martian cloud on the 99th sol, or Martian day, of the mission (Sept. 3, 2008). The vertical streaks at the base of the cloud on the right of the image show ice crystals falling from the cloud, similar to snow. The streaks are curved as the winds are faster around 3 kilometers (almost 2 miles) than at higher altitudes. Scientists are able to determine that the snow is water-based and not carbon-dioxide snow, since temperatures on Mars are currently too warm to support the latter.

  16. 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.

  17. 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.

  18. 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

  19. Martian Dune Field

    NASA Technical Reports Server (NTRS)

    1976-01-01

    This spectacular picture of the Martian landscape by the Viking 1 Lander shows a dune field with features remarkably similar to many seen in the deserts of Earth. The dramatic early morning lighting - 7:30 a.m. local Mars time--reveals subtle details and shading. Taken yesterday (August 3) by the Lander s camera #1, the picture covers 100 , looking northeast at left and southeast at right. Viking scientists have studied areas very much like the one in this view in Mexico and in California (Kelso, Death Valley, Yuma). The sharp dune crests indicate the most recent wind storms capable of moving sand over the dunes in the general direction from upper left to lower right. Small deposits downwind of rocks also indicate this wind direction. Large boulder at left is about eight meters (25 feet) from the spacecraft and measures about one by three meters (3 by 10 feet). The meteorology boom, which supports Viking s miniature weather station, cuts through the picture s center. The sun rose two hours earlier and is about 30 above the horizon near the center of the picture.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Telltale Instrument Waving in the Martian Wind

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This series of images show Phoenix's telltale instrument waving in the Martian wind. Documenting the telltale's movement helps mission scientists and engineers determine what the wind is like on Mars.

    On the day these images were taken, one of the images seemed to be 'out-of-phase' with other images, possibly indicating a dust devil occurrence. Preliminary analysis of the images taken right before and after the passing of this possible dust devil indicates winds from the west at 7 meters per second. The image taken during the possible dust devil shows 11 meters per second wind from the south.

    These images were taken by the lander's Surface Stereo Imager (SSI) on the 136th Martian day, or sol, of the mission (Oct. 12, 2008). Phoenix's telltale is part of the Canadian Space Agency's meteorological package on 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.

  6. 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).

  7. Martian Dunes in Infrared

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This collage of six images taken by the camera system on NASA's Mars Odyssey, shows examples of the daytime temperature patterns of martian dunes seen by the infrared camera. The dunes can be seen in this daytime image because of the temperature differences between the sunlit (warm and bright) and shadowed (cold and dark) slopes of the dunes. The temperatures in each image vary, but typically range from approximately -35 degrees Celsius (-31 degrees Fahrenheit) to -15degrees Celsius (5 degrees Fahrenheit). Each image covers an area approximately 32 by 32 kilometers (20 by 20 miles) and was acquired using the infrared Band 9, centered at 12.6 micrometers. Clockwise from the upper left, these images are: (a) Russel crater, 54 degrees south latitude, 13 degrees east longitude; (b) Kaiser crater. 45degrees south latitude, 19 degrees east longitude; (c) Rabe crater, 43south latitude, 35 east longitude; (d) 22 north latitude, 66 degrees east longitude; (e) Proctor crater. 47 degrees south latitude, 30 degrees east longitude; (f) 61 degrees south latitude, 201 degrees east longitude.

    The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the 2001 Mars Odyssey mission for NASA's Office of Space Science in Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson and NASA's Johnson Space Center, Houston, operate the science instruments. Additional science partners are located at the Russian Aviation and Space Agency and at Los Alamos National Laboratories, New Mexico. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL.

  8. 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.

  9. 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.

  10. Composition of the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Ott, U.

    1991-04-01

    Data on the composition of the Martian atmosphere obtained by instruments aboard the Viking spacecraft are not of sufficient accuracy to address important questions regarding the compsition and history of Mars. Laboratory analyses of gases trapped in glassy phases of shergottite meteorite EETA 79001 yield precise data, but it remains to be ascertained that these gases constitute unfractionated Martian atmosphere. Return from Mars of a gas sample for laboratory analysis appears preferable to another in situ measurement, especially if rocks of documented origin will become available for gas analysis as well.

  11. 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.

  12. Phoenix Conductivity Probe Inserted in Martian Soil

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This series of six images from the Robotic Arm Camera on NASA's Phoenix Mars Lander records the first time that the four spikes of the lander's thermal and electrical conductivity probe were inserted into Martian soil.

    The images were taken on July 8, 2008, during the Phoenix mission's 43rd Martian day, or sol, since landing. The insertion visible from the shadows cast on the ground on that sol was a validation test of the procedure. The spikes on the probe are about 1.5 centimeters or half an inch long.

    The science team will use the probe tool to assess how easily heat and electricity move through the soil from one spike to another. Such measurements can provide information about frozen or unfrozen water in the soil. The probe is mounted on the 'knuckle' of Phoenix's Robotic Arm. It has already been used for assessing water vapor in the atmosphere when it is held above the ground.

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

  13. Martian Soil Ready for Robotic Laboratory Analysis

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Phoenix Mars Lander scooped up this Martian soil on the mission's 11th Martian day, or sol, after landing (June 5, 2008) as the first soil sample for delivery to the laboratory on the lander deck.

    The material includes a light-toned clod possibly from crusted surface of the ground, similar in appearance to clods observed near a foot of the lander.

    This approximately true-color view of the contents of the scoop on the Robotic Arm comes from combining separate images taken by the Robotic Arm Camera on Sol 11, using illumination by red, green and blue light-emitting diodes on the camera.

    The scoop loaded with this sample was poised over an open sample-delivery door of Thermal and Evolved-Gas Analyzer at the end of Sol 11, ready to be dumped into the instrument on the next sol.

    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.

  14. Acoustics in the Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Williams, J.-P.

    2000-10-01

    With the advent of the first attempt to deliver an acoustic microphone to the Martian surface aboard the failed Mars Polar Lander, there has been growing interests in the development of acoustic sensors to compliment scientific payloads on future spacecraft. Terrestrial scientist have been very successful in using infrasound (sound at frequencies below human detection, < 20 Hz) to detect and monitor atmospheric phenomena related to weather, tornadoes, mountain waves, microbaroms, ionospheric and auroral disturbances, and meteror/fireballs, as well as anthropogenic sources such as aircraft and nuclear explosions. Sounds on Mars at the audible frequencies (20 Hz to 20 kHz) will be severely attenuated due to viscous relaxation and thermal diffusion (collectively referred to as classical attenuation) which will be much more severe in the colder, less dense Martian atmosphere. Molecular relaxation of carbon dioxide will also contribute to the sound absorption in the lower audible frequencies. Since classical attenuation increases as a function of the frequency squared, at low infrasonic frequencies ( < 10 Hz), classical attenuation becomes less significant and sound absorption in the Martian atmosphere becomes more similar to that of the terrestrial atmosphere for the same frequencies. At these longer wavelengths, geometric spreading will dominate as the source of attenuation as the acoustic energy is spread out over an ever increasing spherical wave front. This implies that infrasound (10 to 0.01 Hz) will be a useful frequency range for future acoustic sensors developed for scientific payloads delivered to the Martian surface.

  15. 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)

  16. 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.

  17. 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

  18. Evolution of the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Pepin, R. O.

    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

  19. 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.

  20. 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.

  1. Day to Day

    ERIC Educational Resources Information Center

    Jurecki, Dennis

    2006-01-01

    A clean, healthy and safe school provides students, faculty and staff with an environment conducive to learning and working. However, budget and staff reductions can lead to substandard cleaning practices and unsanitary conditions. Some school facility managers have been making the switch to a day-schedule to reduce security and energy costs, and…

  2. 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.

  3. 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.

  4. Martian deltas: Morphology and distribution

    NASA Technical Reports Server (NTRS)

    Rice, J. W., Jr.; Scott, D. H.

    1993-01-01

    Recent detailed mapping has revealed numerous examples of Martian deltas. The location and morphology of these deltas are described. Factors that contribute to delta morphology are river regime, coastal processes, structural stability, and climate. The largest delta systems on Mars are located near the mouths of Maja, Maumee, Vedra, Ma'adim, Kasei, and Brazos Valles. There are also several smaller-scale deltas emplaced near channel mouths situated in Ismenius Lacus, Memnonia, and Arabia. Delta morphology was used to reconstruct type, quantity, and sediment load size transported by the debouching channel systems. Methods initially developed for terrestrial systems were used to gain information on the relationships between Martian delta morphology, river regime, and coastal processes.

  5. Newly Discovered Martian Impact Basins

    NASA Technical Reports Server (NTRS)

    Stam, M.

    1985-01-01

    Three previously unrecognized Martian impact basins were discovered through detailed mapping of landforms, structures and terrains near Cassini and Al Qahira basins. Al Qahira A lies on the Martian dichotomy boundary and intersects the older basin, Al Qahira. It has four rings that are expressed by a variety of landforms. Southwestward Al Qahira A is out by a younger Basin, Al Qahira B. Al Qahira B is a highly degraded basin with one identifiable ring. Its ring is expressed by a few massifs, knobs and inward-facing scarps, but is recognized by the distributions of wrinkle ridges and plains units. Cassini A lies southward of the younger Cassini Basin and is intersected by it. It probably has four rings. The importance of detailed mapping of various types of landforms and terrains to the discovery of basins on Mars are demonstrated.

  6. Flank tectonics of Martian volcanoes

    NASA Technical Reports Server (NTRS)

    Thomas, Paul J.; Squyres, Steven W.; Carr, Michael H.

    1990-01-01

    The origin of the numerous terraces on the flanks of the Olympus Mons volcano on Mars, seen on space images to be arranged in a roughly concentric pattern, is investigated. The images of the volcano show that the base of each terrace is marked by a modest but abrupt change in slope, suggesting that these terraces could be thrust faults caused by a compressional failure of the cone. The mechanism of faulting and the possible effect of the interior structure of Olympus Mons was investigated using a numerical model for elastic stresses within a Martian volcano, constructed for that purpose. Results of the analysis supports the view that the terraces on Olympus Mons, as well as on other three Martian volcanoes, including Ascraeus Mons, Arsia Mons, and Pavonis Mons are indeed thrust faults.

  7. The Martian impact cratering record

    NASA Technical Reports Server (NTRS)

    Strom, Robert G.; Croft, Steven K.; Barlow, Nadine G.

    1992-01-01

    A detailed analysis of the Martian impact cratering record is presented. The major differences in impact crater morphology and morphometry between Mars and the moon and Mercury are argued to be largely the result of subsurface volatiles on Mars. In general, the depth to these volatiles may decrease with increasing latitude in the southern hemisphere, but the base of this layer may be at a more or less constant depth. The Martial crustal dichotomy could have been the result of a very large impact near the end of the accretion of Mars. Monte Carlo computer simulations suggest that such an impact was not only possible, but likely. The Martian highland cratering record shows a marked paucity of craters less than about 30 km in diameter relative to the lunar highlands. This paucity of craters was probably the result of the obliteration of craters by an early period of intense erosion and deposition by aeolian, fluvial, and glacial processes.

  8. Hydrogen Isotopic Systematics of Nominally Anhydrous Phases in Martian Meteorites

    NASA Astrophysics Data System (ADS)

    Tucker, Kera

    Hydrogen isotope compositions of the martian atmosphere and crustal materials can provide unique insights into the hydrological and geological evolution of Mars. While the present-day deuterium-to-hydrogen ratio (D/H) of the Mars atmosphere is well constrained (~6 times that of terrestrial ocean water), that of its deep silicate interior (specifically, the mantle) is less so. In fact, the hydrogen isotope composition of the primordial martian mantle is of great interest since it has implications for the origin and abundance of water on that planet. Martian meteorites could provide key constraints in this regard, since they crystallized from melts originating from the martian mantle and contain phases that potentially record the evolution of the H 2O content and isotopic composition of the interior of the planet over time. Examined here are the hydrogen isotopic compositions of Nominally Anhydrous Phases (NAPs) in eight martian meteorites (five shergottites and three nakhlites) using Secondary Ion Mass Spectrometry (SIMS). This study presents a total of 113 individual analyses of H2O contents and hydrogen isotopic compositions of NAPs in the shergottites Zagami, Los Angeles, QUE 94201, SaU 005, and Tissint, and the nakhlites Nakhla, Lafayette, and Yamato 000593. The hydrogen isotopic variation between and within meteorites may be due to one or more processes including: interaction with the martian atmosphere, magmatic degassing, subsolidus alteration (including shock), and/or terrestrial contamination. Taking into consideration the effects of these processes, the hydrogen isotope composition of the martian mantle may be similar to that of the Earth. Additionally, this study calculated upper limits on the H2O contents of the shergottite and nakhlite parent melts based on the measured minimum H2O abundances in their maskelynites and pyroxenes, respectively. These calculations, along with some petrogenetic assumptions based on previous studies, were subsequently used

  9. Do oblique impacts produce Martian meteorites?

    NASA Astrophysics Data System (ADS)

    Nyquist, L. E.

    Geochronological and geochemical characteristics of several achondritic meteorites match those expected of Martian rocks. Several authors have suggested that these meteorites might have originated on Mars, but no satisfactory explanation has been given of how they may have been ejected from the Martian surface. It is suggested that the oblique impact of large meteoroids may produce ejecta which is entrained with the ricocheting projectile and accelerated to velocities in excess of Martian escape velocity. This suggestion is based on earlier experimental studies of oblique impacts and on the observation of several large Martian craters with the characteristic 'butterfly' ejecta pattern produced by low angle impacts. Several acceleration mechanisms may act on the Martian ejecta. The considerations suggest that a Martian origin of the shergottite meteorites is dynamically possible.

  10. 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

  11. Lunar and Martian hardware commonality

    NASA Technical Reports Server (NTRS)

    Davis, Hubert P.; Johnson, Robert E.; Phillips, Paul G.; Spear, Donald S.; Stump, William R.; Williams, Franklin U.

    1986-01-01

    A number of different hardware elements were examined for possible Moon/Mars program commonality. These include manned landers; cargo landers, a trans-Mars injection (TMI) stage, traverse vehicles, unmanned surface rovers, habitation modules, and power supplies. Preliminary analysis indicates that it is possible to build a common two-stage manned lander. A single-stage, reusable lander may be practical for the lunar cast, but much less so for the Martian case, and commonality may therefore exist only at the subsystem level. A modified orbit transfer vehicle was examined as a potential cargo lander. Potential cargoes to various destinations were calculated for a Shuttle external tank sized TMI stage. A nuclear powered, long range traverse vehicle was conceptually designed and commonality is considered feasible. Short range, unmanned rovers can be made common without great effort. A surface habitation module may be difficult to make common due to difficulties in landing certain shapes on the Martian surface with aerobraking landers. Common nuclear power sources appear feasible. High temperature radiators appear easy to make common. Low temperature radiators may be difficult to make common. In most of these cases, Martian requirements determine the design.

  12. 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.

  13. 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.

  14. 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.

  15. New insights into martian atmospheric chemistry

    NASA Astrophysics Data System (ADS)

    Boxe, C. S.; Francisco, J. S.; Shia, R.-L.; Yung, Y. L.; Nair, H.; Liang, M.-C.; Saiz-Lopez, A.

    2014-11-01

    HOx radicals are produced in the martian atmosphere by the photolysis of water vapor and subsequently participate in catalytic cycles that recycle carbon dioxide (CO2) from its photolysis product carbon monoxide (CO), providing a qualitative explanation for the stability of its atmosphere. Balancing CO2 production and loss based on our current understanding of martian gas-phase chemistry has, however, proven to be difficult. The photolysis of O3 produces O(1D), while oxidation of CO produces HOCO radicals, a new member of the HOx family. The O(1D) quantum yield has recently been updated, which quantifies nonzero quantum yields in the Huggins bands. In Earth's atmosphere HOCO is considered to be unimportant since it is quickly removed by abundant oxygen molecules. The smaller amount of O2 in the Mars' atmosphere causes HOCO's lifetime to be longer in Mars' atmosphere than Earth's (3 × 10-5 s to 1.2 days from Mars's surface to 240 km, respectively). Limited kinetic data on reactions involving HOCO prevented consideration of its reactions directly in atmospheric models. Therefore, the impact of HOCO reactions on martian chemistry is currently unknown. Here, we incorporate new literature rate constants for HOCO chemistry and an updated representation of the O(1D) quantum yield in the Caltech/JPL 1-D photochemical model for Mars' atmosphere. Our simulations exemplify perturbations to NOy, HOx, and COx species, ranging from 5% to 50%. The modified O(1D) quantum yield and new HOCO chemistry cause a 10% decrease and a 50% increase in OH and H2O2 total column abundances, respectively. At low altitudes, HOCO production contributes 5% towards CO2 production. Given recent experimentally-obtained branching ratios for the oxidation of CO, HOCO may contribute up to 70% toward the production of NOy, where HOx and NOy species are enhanced up to a factor 3, which has implications for rethinking the fundamental understanding of NOy, HOx, and CO/CO2 cycling on Mars. Two new reaction

  16. Lunar and martian meteorite delivery services

    NASA Technical Reports Server (NTRS)

    Warren, Paul H.

    1994-01-01

    Launch mechanisms for lunar and martian meteorites have been investigated, by integrating physical modeling constraints, geochemical cosmic-ray exposure (CRE) constraints, and petrologic constraints. The potential source region for lunar meteorites is remarkably small compared to the final crater volume. CRE constraints indicate that most launches start at depths of less than or equal to 3.2 m, and cratering theory implies derivation of suitably accelerated objects from a subvolume with diameter only about 0.3 x the final crater diameter. The shallow depth provenance is probably related to shock-wave interference, enhanced by the lunar regolith's extremely low compressional wave velocity. CRE constraints alone imply that four to five separate launch events are represented among the eight well-studied lunar meteorites. Most of the lunar meteorites are regolith breccias, which tend to show only limited compositional diversity within any kilometer-scale region of the Moon. Several others are polymict breccias, which also show relatively subdued compositional diversity, compared to igneous rocks. The observed diversity among these samples in terms of abundances of mare basalt and KREEP, and in Mg/(Mg + Fe) ratio, implies that among eight well-studied lunar meteorites only two potential source craters pairings are plausible: between Asuka-881757 + Y-793169 (most probable) and between Y-793274 + EET875721. Altogether, these eight lunar meteorites apparently represent at least six separate source craters, including three in the past 10(exp 5) years and five in the past 10(exp 6) years. CRE constraints imply that SNC meteorites are launched from systematically greater than lunar meteorites. SNCs are also systematically bigger, and all nine well-studied SNCs are uncommonly young (by martian standards) mafic igneous rocks. Comparison between Viking and Apollo results reveals that rocks the size of common meteorites are remarkably scarce in the martian regolith, probably due

  17. Principal Components Analysis Studies of Martian Clouds

    NASA Astrophysics Data System (ADS)

    Klassen, D. R.; Bell, J. F., III

    2001-11-01

    We present the principal components analysis (PCA) of absolutely calibrated multi-spectral images of Mars as a function of Martian season. The PCA technique is a mathematical rotation and translation of the data from a brightness/wavelength space to a vector space of principal ``traits'' that lie along the directions of maximal variance. The first of these traits, accounting for over 90% of the data variance, is overall brightness and represented by an average Mars spectrum. Interpretation of the remaining traits, which account for the remaining ~10% of the variance, is not always the same and depends upon what other components are in the scene and thus, varies with Martian season. For example, during seasons with large amounts of water ice in the scene, the second trait correlates with the ice and anti-corrlates with temperature. We will investigate the interpretation of the second, and successive important PCA traits. Although these PCA traits are orthogonal in their own vector space, it is unlikely that any one trait represents a singular, mineralogic, spectral end-member. It is more likely that there are many spectral endmembers that vary identically to within the noise level, that the PCA technique will not be able to distinguish them. Another possibility is that similar absorption features among spectral endmembers may be tied to one PCA trait, for example ''amount of 2 \\micron\\ absorption''. We thus attempt to extract spectral endmembers by matching linear combinations of the PCA traits to USGS, JHU, and JPL spectral libraries as aquired through the JPL Aster project. The recovered spectral endmembers are then linearly combined to model the multi-spectral image set. We present here the spectral abundance maps of the water ice/frost endmember which allow us to track Martian clouds and ground frosts. This work supported in part through NASA Planetary Astronomy Grant NAG5-6776. All data gathered at the NASA Infrared Telescope Facility in collaboration with

  18. FTIR Spectra of Possible End Products of Martian Surface Weathering

    NASA Astrophysics Data System (ADS)

    Maxe, L. P.

    2008-03-01

    Comparative analysis of IR spectra shows that martian weathering can lead to separating destruction of surface rocks. The semi-cosmic martian weathering results in amorphous silica dust and open unique ferry aluminum/ferry silicate martian rocks.

  19. Martian Radiation Environment Experiment (MARIE)

    NASA Astrophysics Data System (ADS)

    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

  20. New Martian satellite search

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The approach pictures taken by the Viking 1 and Viking 2 spacecrafts two days before their Mars orbital insertion maneuvers were analyzed in order to search for new satellites within the orbit of Phobos. To accomplish this task, search procedure and analysis strategy were formulated, developed and executed using the substantial image processing capabilities of the Image Processing Laboratory at the Jet Propulsion Laboratory. The development of these new search capabilities should prove to be valuable to NASA in processing of image data obtained from other spacecraft missions. The result of applying the search procedures to the Viking approach pictures was as follows: no new satellites of comparable size (approx. 20 km) and brightness to Phobos or Demios were detected within the orbit of Phobos.

  1. 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.

  2. Martian water: are there extant halobacteria on Mars?

    NASA Technical Reports Server (NTRS)

    Landis, G. A.

    2001-01-01

    On Earth, life exists in all niches where water exists in liquid form for at least a portion of the year. On Mars, any liquid water would have to be a highly concentrated brine solution. It is likely, therefore, that any present-day Martian microorganisms would be similar to terrestrial halophiles. Even if present-day life does not exist on Mars, it is an interesting speculation that ancient bacteria preserved in salt deposits could be retrieved from an era when the climate of Mars was more conducive to life.

  3. 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.

  4. Alaskan thermokarst terrain and possible Martian analog

    NASA Technical Reports Server (NTRS)

    Gatto, L. W.; Anderson, D. M.

    1975-01-01

    A first-order analog to Martian fretted terrain has been recognized on enhanced, ERTS-1 (Earth Resources Technology Satellite) imagery of Alaskan Arctic thermokarst terrain. The Alaskan analog displays flat-floored valleys and intervalley uplands characteristic of fretted terrain. The thermokarst terrain has formed in a manner similar to one of the processes postulated for the development of the Martian fretted terrain.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Flank tectonics of Martian volcanoes

    SciTech Connect

    Thomas, P.J. ); Squyres, S.W. ); Carr, M.H. )

    1990-08-30

    On the flanks of Olympus Mons is a series of terraces, concentrically distributed around the caldera. Their morphology and location suggest that they could be thrust faults caused by compressional failure of the cone. In an attempt to understand the mechanism of faulting and the possible influences of the interior structure of Olympus Mons, the authors have constructed a numerical model for elastic stresses within a Martian volcano. In the absence of internal pressurization, the middle slopes of the cone are subjected to compressional stress, appropriate to the formation of thrust faults. These stresses for Olympus Mons are {approximately}250 MPa. If a vacant magma chamber is contained within the cone, the region of maximum compressional stress is extended toward the base of the cone. If the magma chamber is pressurized, extensional stresses occur at the summit and on the upper slopes of the cone. For a filled but unpressurized magma chamber, the observed positions of the faults agree well with the calculated region of high compressional stress. Three other volcanoes on Mars, Ascraeus Mons, Arsia Mons, and Pavonis Mons, possess similar terraces. Extending the analysis to other Martian volcanoes, they find that only these three and Olympus Mons have flank stresses that exceed the compressional failure strength of basalt, lending support to the view that the terraces on all four are thrust faults.

  11. 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.

  12. Water Extraction from Martian Soil

    NASA Astrophysics Data System (ADS)

    Wiens, J.; Bommarito, F.; Blumenstein, E.; Ellsworth, M.; Cisar, T.; McKinney, B.; Knecht, B.

    2001-01-01

    With the projected growth in space exploration, several milestones have been set for future space programs. One milestone in particular is the landing of a human on the planet Mars. However, one major barrier to the successful placement of persons on Mars is a lack of water on the Martian surface. Because of the massive quantity of water that would be necessary for a mission to Mars, it is not possible to transport the amount necessary from Earth to Mars. Water would be necessary for human consumption as well as a base for jet propulsion fuel. Past unmanned missions to Mars, such as the Viking missions of the 1970's, have revealed the presence of small quantities of water in Martian soil. Research has determined that the water in the soil can be recovered when the soil is heated to a temperature between 200 C and 500 C. Team JFEET has designed a system with the capability to extract water from the soil of Mars, and then meter and deliver the water to a storage tank for later use.

  13. MOC Views of Martian Solar Eclipses

    NASA Technical Reports Server (NTRS)

    1999-01-01

    -middle-right (Ascraeus Mons).

    Phobos and the smaller, more distant satellite, Deimos, were discovered in 1877 by Asaph Hall, an astronomer at the United States Naval Observatory in Washington, D.C. Hall had been hunting for martian satellites for some time, and was about to abandon the search when he was encouraged by his wife to continue. In honor of her role, the largest crater on Phobos was named Stickney, her maiden name. Phobos is a tiny, potato-shaped world that is only about 13 km by 11 km by 9 km (8 mi by 7 mi by 6 mi) in size.

    In 1912 Edgar Rice Burroughs published a story entitled 'Under the Moons of Mars' (printed in book form in 1917 as A Princess of Mars) in which he referred to the 'hurtling moons of Barsoom' (Barsoom being the 'native' word for Mars in the fictional account). Burroughs was inspired by the fact that Phobos, having an orbital period of slightly less than 8 hours, would appear from Mars to rise in the west and set in the east only five and a half hours later. (Despite Burroughs' phrase, the outer moon, Deimos, can hardly be said to 'hurtle' -- it takes nearly 60 hours to cross the sky from east to west, rising on one day and not setting again for over two more.)

    If you could stand on Mars and watch Phobos passing overhead, you would notice that this moon appears to be only about half the size of what Earth's Moon looks like when viewed from the ground. In addition, the Sun would seem to have shrunk to about 2/3 (or nearly 1/2) of its size as seen from Earth. Martian eclipses are therefore dark but not as spectacular as total solar eclipses on Earth can be. In compensation, the martian eclipses are thousands of times more common, occurring a few times a day somewhere on Mars whenever Phobos passes over the planet's sunlit side. Due to the changing geometry of the MGS orbit relative to that of Phobos, the shadow is actually seen in MOC global map images (like in the second figure above) about a dozen times a month.

    The shadow of Phobos was seen

  14. Ensemble Kalman Filter Data Assimilation for the Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Hoffman, Matthew J.; Greybush, S.; Wilson, R. J.; Gyarmati, G.; Ide, K.; Miyoshi, T.; Szunyogh, I.; Kalnay, E.

    2009-09-01

    A data assimilation system provides a means of optimally combining information from sparse observations and an atmospheric model to provide an accurate depiction of the state of a planetary atmosphere. Here a Mars General Circulation Model (MGCM) is coupled with the local ensemble transform Kalman filter (LETKF) as the basis of an advanced data assimilation system for Mars. Identical twin experiments, in which observations are generated synthetically from a nature run of the MGCM to approximate the spatial distribution of PDS TES profiles, explore the potential of ensemble data assimilation for the Martian atmosphere. The experiments find that the LETKF is able to correct errors in the Martian atmospheric model and improve the state estimates of the temperature and wind fields, even in the absence of wind observations. The error in the state estimate quickly reduces to below the observation error, and both the forecast and subsequent analysis errors remain low for the duration of a 60 day simulation. Large-scale baroclinic waves along the Northern (winter) Hemisphere temperature front and instabilities in the upper atmosphere zonal wind jet are two predominant sources of error in the MGCM-LETKF system. This study forms the first step toward creating the MGCM-LETKF Martian Atmosphere Reanalysis, which will be incorporating real observations obtained from the MGS TES instrument.

  15. 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

  16. 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.

  17. Microscopic Image of Martian Surface Material on a Silicone Substrate

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for larger version of Figure 1

    This image taken by the Optical Microscope on NASA's Phoenix Mars Lander shows soil sprinkled from the lander's Robot Arm scoop onto a silicone substrate. The substrate was then rotated in front of the microscope. This is the first sample collected and delivered for instrumental analysis onboard a planetary lander since NASA's Viking Mars missions of the 1970s. It is also the highest resolution image yet seen of Martian soil.

    The image is dominated by fine particles close to the resolution of the microscope. These particles have formed clumps, which may be a smaller scale version of what has been observed by Phoenix during digging of the surface material.

    The microscope took this image during Phoenix's Sol 17 (June 11), or the 17th Martian day after landing. The scale bar is 1 millimeter (0.04 inch).

    Zooming in on the Martian Soil

    In figure 1, three zoomed-in portions are shown with an image of Martian soil particles taken by the Optical Microscope on NASA's Phoenix Mars Lander.

    The left zoom box shows a composite particle. The top of the particle has a green tinge, possibly indicating olivine. The bottom of the particle has been reimaged at a different focus position in black and white (middle zoom box), showing that this is a clump of finer particles.

    The right zoom box shows a rounded, glassy particle, similar to those which have also been seen in an earlier sample of airfall dust collected on a surface exposed during landing.

    The shadows at the bottom of image are of the beams of the Atomic Force Microscope.

    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. 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.

  19. 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.

  20. Martian regolith as space radiation shielding

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    Mars exploration crews will be exposed to such high radiation dosages in route from earth that as to sharply reduce the allowable dose they should receive while on the Martian surface. An account is presently given of the possibility of using Martian regolith as crew shielding to maintain very low short-term dose limits. NASA-Langley's nucleon and heavy-ion transport computer codes are used to predict the propagation and interaction of the free-space nucleons and heavy ions through the Martian atmosphere and then through various thicknesses of regolith. The largest reduction in dose occurs in the first 15-20 cm of regolith material.

  1. Degradation studies of Martian impact craters

    NASA Technical Reports Server (NTRS)

    Barlow, N. G.

    1991-01-01

    The amount of obliteration suffered by Martian impact craters is quantified by comparing measurable attributes of the current crater shape to those values expected for a fresh crater of identical size. Crater diameters are measured from profiles obtained using photoclinometry across the structure. The relationship between the diameter of a fresh crater and a crater depth, floor width, rim height, central peak height, etc. was determined by empirical studies performed on fresh Martian impact craters. We utilized the changes in crater depth and rim height to judge the degree of obliteration suffered by Martian impact craters.

  2. A model of Martian surface chemistry

    NASA Technical Reports Server (NTRS)

    Oyama, V. I.; Berdahl, B. J.

    1979-01-01

    Alkaline earth and alkali metal superoxides and peroxides, gamma-Fe2O3 and carbon suboxide polymer, are proposed to be constituents of the Martian surface material. These reactive substances explain the water modified reactions and thermal behaviors of the Martian samples demonstrated by all of the Viking Biology Experiments. It is also proposed that the syntheses of these substances result mainly from electrical discharges between wind-mobilized particles at Martian pressures; plasmas are initiated and maintained by these discharges. Active species in the plasma either combine to form or react with inorganic surfaces to create the reactive constituents.

  3. 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.

  4. Atomic oxygen in the Martian thermosphere

    NASA Technical Reports Server (NTRS)

    Stewart, A. I. F.; Alexander, M. J.; Meier, R. R.; Paxton, L. J.; Bougher, S. W.; Fesen, C. G.

    1992-01-01

    Modern models of thermospheric composition and temperature and of excitation and radiative transfer processes are used to simulate the O I 130-nm emission from Mars measured by the Mariner 9 ultraviolet spectrometer. This paper uses the Mars thermospheric general circulation model calculations (MTGCM) of Bougher et al. (1988) and the Monte Carlo partial frequency redistribution multiple scattering code of Meier and Lee (1982). It is found that the decline in atomic oxygen through the daylight hours predicted by the MTGCM cannot be reconciled with the excess afternoon brightness seen in the data. Oxygen concentrations inferred from the data show a positive gradient through the day, in agreement with the original analysis by Strickland et al. (1973). In addition, the data suggest that the oxygen abundance increases toward high southerly latitudes, in contrast with the MTGCM prediction of high values in the Northern Hemisphere. It appears that solar forcing alone cannot account for the observed characteristics of the Martian thermosphere and that wave and tidal effects may profoundly affect the structure, winds, and composition.

  5. 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.

  6. 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.

  7. Variability of the Martian thermosphere during eight Martian years as simulated by a ground-to-exosphere global circulation model

    NASA Astrophysics Data System (ADS)

    González-Galindo, F.; López-Valverde, M. A.; Forget, F.; García-Comas, M.; Millour, E.; Montabone, L.

    2015-11-01

    Using a ground-to-exosphere general circulation model for Mars we have simulated the variability of the dayside temperatures at the exobase during eight Martian years (MY, from MY24 to MY31, approximately from 1998 to 2013), taking into account the observed day-to-day solar and dust load variability. We show that the simulated temperatures are in good agreement with the exospheric temperatures derived from Precise Orbit Determination of Mars Global Surveyor. We then study the effects of the solar variability and of two planetary-encircling dust storms on the simulated temperatures. The seasonal effect produced by the large eccentricity of the Martian orbit translates in an aphelion-to-perihelion temperature contrast in every simulated year. However, the magnitude of this seasonal temperature variation is strongly affected by the solar conditions, ranging from 50 K for years corresponding to solar minimum conditions to almost 140 K during the last solar maximum. The 27 day solar rotation cycle is observed on the simulated temperatures at the exobase, with average amplitude of the temperature oscillation of 2.6 K but with a significant interannual variability. These two results highlight the importance of taking into account the solar variability when simulating the Martian upper atmosphere and likely have important implications concerning the atmospheric escape rate. We also show that the global dust storms in MY25 and MY28 have a significant effect on the simulated temperatures. In general, they increase the exospheric temperatures over the low latitude and midlatitude regions and decrease them in the polar regions.

  8. Of Martian atmospheres, oceans, and fossils

    NASA Astrophysics Data System (ADS)

    Helfer, H. L.

    1990-09-01

    A scenario is presently developed in which a substantial resemblance between Martian conditions up to 1.5 Gyr ago and those of the ancient earth led to the development of rudimentary life in Mars, in stages and on timescales that may be broadly comparable to terrestrial ones. The warm Martian oceans would give rise to both aerobic and anaerobic photosynthesizing prokaryotes, as well as such structures as stromatolites, which could in due course have transformed the Martian atmosphere as profoundly as those on earth. It is anticipated that the fossil remains of these rudimentary organisms can be found along the fringes of the ancient Martian oceans, which currently take the form of northern lowland plains.

  9. A Meteor Shower Origin for Martian Methane

    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.

    2015-07-01

    We present and discuss the hypothesis that martian methane arises from a meteor shower source. Infall material produces methane by UV photolysis, generating localized plumes that occur after Mars/comet orbit interactions. This hypothesis is testable.

  10. The Argentinean Patagonia and the Martian landscape

    NASA Astrophysics Data System (ADS)

    Pacifici, Andrea

    2009-05-01

    Throughout the Cenozoic Era, the geological history of the Argentinean Patagonia was dominated by basaltic volcanism and glacial and periglacial environments. Several geological and geomorphological processes that concurred to the sculpting of the landscape of this area could have been similar to those responsible of the shaping of the Martian surface. In this work a survey of some high-resolution satellite images of the Argentinean Patagonia is performed in order to identify possible geomorphological analogs of the Martian surface. Several morphologies that resemble Martian features are presented and discussed. They consist of proglacial and periglacial features, relatively small circular depressions, gullies, fan-deltas, eolian streaks, and diluvial dunes. Results suggest that the Argentinean Patagonia appears to consist of an interesting terrestrial analog for the Martian landscape. Furthermore, the study area shows to be interesting in order to test robotic instruments and human missions equipment, to train astronauts of future human expeditions to Mars, and to perform astrobiological experiments.

  11. Martian Unbound Water Inventories: Changes with Time

    NASA Astrophysics Data System (ADS)

    Carr, M. H.; Head, J. W.

    2014-07-01

    We estimate that approximately 34 m GEL of unbound water is within 100 m of the martian surface today and 60-70 m are estimated for the end of the Hesperian. These estimates are reconciled with the geology.

  12. Evaluation of wind electric energy based on martian wind measurements

    NASA Astrophysics Data System (ADS)

    Nishikawa, Y.; Kurita, K.

    2012-12-01

    Since Mars is characterized by strong surface wind, electric power generation by the wind activity has been proposed as a possible power source for martian base station as well as that for exploration module (George James et al., 1999, Vimal Kumar et al., 2010). George and Vimal estimated total power as 19kW and 500W, which they conclude is sufficient value as a power source of small exploration module. These values seem comparable to that used in MER( 900Wh per day ). But their estimate largely depends on the model of wind velocity and reevaluation is necessary based on plausible wind model as well as more realistic assumptions about power generation. This study evaluates plausible range of available power by using surface wind model estimated by Viking Lander measurements. Meteorological package of Viking Lander measured wind velocity and its direction at 1.6m hight at every 60 min. for 200 sols. We estimate wind statistics by using Weibull distribution function and elevation offset. We calculate the wind energy by wind turbines as the integrated value of power produced in a Martian day, and compare with solar panel and nuclear battery under various conditions (Mars ground roughness, blade length, shape of wind turbine and rotor height from the ground). As a result of the calculations, we obtain reasonable amount of wind electricity (1000 Wh per day ), which can be used if we select proper locations and suitable wind turbine.

  13. Martian Sunrise at Phoenix Landing Site, Sol 101

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This sequence of nine images taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander shows the sun rising on the morning of the lander's 101st Martian day after landing.

    The images were taken on Sept. 5, 2008. The local solar times at the landing site for the nine images were between 1:23 a.m. and 1:41 a.m.

    The landing site is on far-northern Mars, and the mission started in late northern spring. For nearly the entire first 90 Martian days of the mission, the sun never set below the horizon. As the amount of sunshine each day declined steadily after that, so has the amount of electricity available for the solar-powered spacecraft.

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

  14. 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?

  15. 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.

  16. 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.

  17. 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.

  18. Sensitivity of Martian circulation to obliquity changes

    NASA Astrophysics Data System (ADS)

    Segschneider, J.; Grieger, B.; Lunkeit, F.; Kirk, E.

    2003-04-01

    The obliquity of the Martian rotation axis varies between 15 and 35 degrees with main periods of 125 kyr and 1.3 My. This is thought to have similar impact on the Martian climate as the Milancovic cycles on Earth. The northern layered terrains indicate that climate cycles of yet unknown nature have led to varying accumulation and ablation rates. This study aims at investigating the impact of orbital changes on the Martian atmospheric circulation, while an accompanying study (CR5.05) aims at exploring the internal dynamics of the ice sheet. Here, PUMA, the Portable University Model of the Atmosphere, is used in the Martian set-up to perform sensitivity studies for minimum and maximum obliquity. PUMA is a spectral model with sigma co-ordinates that solves the dynamical equations for vorticity and divergence. Additional modules compute radiative transfers, the soil temperature and heat fluxes between the surface and the atmosphere. So far PUMA has been sucesfully used for modelling of the terrestial climate. As a first step towards a more complete simulation of the evolution of the Martian climate, simulations over one Martian year for minimum and maximum obliquity will be shown.

  19. 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.

  20. Kindergarten: All Day Every Day?

    ERIC Educational Resources Information Center

    Oelerich, Marjorie L.

    This paper reports findings that all-day every-day educational programs have positive effects on kindergarten children. Also included is a Minnesota Association for Childhood Education (MACE) position paper which advocates the provision of full-day kindergarten programs and details seven criteria that a quality full-day program must meet. Efforts…

  1. Cracks in Martian boulders exhibit preferred orientations that point to solar-induced thermal stress.

    PubMed

    Eppes, Martha-Cary; Willis, Andrew; Molaro, Jamie; Abernathy, Stephen; Zhou, Beibei

    2015-01-01

    The origins of fractures in Martian boulders are unknown. Here, using Mars Exploration Rover 3D data products, we obtain orientation measurements for 1,857 cracks visible in 1,573 rocks along the Spirit traverse and find that Mars rock cracks are oriented in statistically preferred directions similar to those compiled herein for Earth rock cracks found in mid-latitude deserts. We suggest that Martian directional cracking occurs due to the preferential propagation of microfractures favourably oriented with respect to repeating geometries of diurnal peaks in sun-induced thermal stresses. A numerical model modified here with Mars parameters supports this hypothesis both with respect to the overall magnitude of stresses as well as to the times of day at which the stresses peak. These data provide the first direct field and numerical evidence that insolation-related thermal stress potentially plays a principle role in cracking rocks on portions of the Martian surface. PMID:25813699

  2. Effect of shadowing on survival of bacteria under conditions simulating the Martian atmosphere and UV radiation.

    PubMed

    Osman, Shariff; Peeters, Zan; La Duc, Myron T; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri

    2008-02-01

    Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-microm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-microm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (approximately 5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars. PMID:18083857

  3. MOC Views of Martian Solar Eclipses

    NASA Technical Reports Server (NTRS)

    1999-01-01

    -middle-right (Ascraeus Mons).

    Phobos and the smaller, more distant satellite, Deimos, were discovered in 1877 by Asaph Hall, an astronomer at the United States Naval Observatory in Washington, D.C. Hall had been hunting for martian satellites for some time, and was about to abandon the search when he was encouraged by his wife to continue. In honor of her role, the largest crater on Phobos was named Stickney, her maiden name. Phobos is a tiny, potato-shaped world that is only about 13 km by 11 km by 9 km (8 mi by 7 mi by 6 mi) in size.

    In 1912 Edgar Rice Burroughs published a story entitled 'Under the Moons of Mars' (printed in book form in 1917 as A Princess of Mars) in which he referred to the 'hurtling moons of Barsoom' (Barsoom being the 'native' word for Mars in the fictional account). Burroughs was inspired by the fact that Phobos, having an orbital period of slightly less than 8 hours, would appear from Mars to rise in the west and set in the east only five and a half hours later. (Despite Burroughs' phrase, the outer moon, Deimos, can hardly be said to 'hurtle' -- it takes nearly 60 hours to cross the sky from east to west, rising on one day and not setting again for over two more.)

    If you could stand on Mars and watch Phobos passing overhead, you would notice that this moon appears to be only about half the size of what Earth's Moon looks like when viewed from the ground. In addition, the Sun would seem to have shrunk to about 2/3 (or nearly 1/2) of its size as seen from Earth. Martian eclipses are therefore dark but not as spectacular as total solar eclipses on Earth can be. In compensation, the martian eclipses are thousands of times more common, occurring a few times a day somewhere on Mars whenever Phobos passes over the planet's sunlit side. Due to the changing geometry of the MGS orbit relative to that of Phobos, the shadow is actually seen in MOC global map images (like in the second figure above) about a dozen times a month.

    The shadow of Phobos was seen

  4. Magmatic water in the martian meteorite Nakhla

    NASA Astrophysics Data System (ADS)

    Hallis, L. J.; Taylor, G. J.; Nagashima, K.; Huss, G. R.

    2012-12-01

    Mars does not recycle crustal materials via plate tectonics. For this reason the magmatic water reservoir of the martian mantle has not been affected by surface processes, and the deuterium/hydrogen (D/H) ratio of this water should represent the original primordial martian value. Following this logic, hydrous primary igneous minerals on the martian surface should also carry this primordial D/H ratio, assuming no assimilation of martian atmospheric water during crystallization and no major hydrogen fractionation during melt degassing. Hydrous primary igneous minerals, such as apatite and amphibole, are present in martian meteorites here on Earth. Providing these minerals have not been affected by terrestrial weathering, martian atmospheric water, or shock processes after crystallization, they should contain a good approximation of the primordial martian D/H ratio. As Nakhla was seen to fall in the Egyptian desert in 1911, terrestrial contamination is minimized in this meteorite. The nakhlites are also among the least shocked of the martian meteorites. Therefore, apatite within Nakhla could contain primordial martian hydrogen isotope ratios. We produced in-situ measurements of the D/H ratios in Nakhla apatite grains, using a Cameca ims 1280 ion-microprobe. Our measurements produced D/H values in Nakhla apatite similar to terrestrial values, despite strong evidence that our samples were not significantly contaminated by terrestrial hydrogen. These results suggest that water trapped in the martian mantle has a similar D/H to that of the Earth. Therefore, the water of these two planets may have originated from the same source material. The D/H ratios of the carbonaceous chondrite meteorites, and the Jupiter-family comet 103P/Hartley 2, are similar to the D/H of the two planets, making both these primitive inner solar system materials strong candidates for the source of the terrestrial planets water. These results support recent dynamical models of the formation of the

  5. Martian meteorites and Martian magnetic anomalies: A new perspective from NWA 7034

    NASA Astrophysics Data System (ADS)

    Gattacceca, J.; Rochette, P.; Scorzelli, R. B.; Munayco, P.; Agee, C.; Quesnel, Y.; Cournède, C.; Geissman, J.

    2014-07-01

    We present the magnetic properties of the Noachian Martian breccia NWA 7034. Among the 25 unpaired Martian meteorites studied to date, NWA 7034 has a unique magnetic mineralogy. It contains about 15 wt % of iron oxides as magnetite that has experienced cation substitution and partial alteration to maghemite, with about a quarter of the oxides being pure maghemite. It also contains oxyhydroxides in the form of superparamagnetic goethite. The presence of maghemite and goethite makes NWA 7034 the most oxidized Martian meteorite. The overall magnetic assemblage is partly linked to near-surface hydrothermal alteration. The high concentration of magnetic phases with high laboratory unblocking temperatures makes NWA 7034 a plausible analogue source lithology for the strong magnetization of the Martian Noachian crust. Near-surface hydrothermal alteration can enhance the remanence of Martian rocks and account for local, high magnetic anomalies of shallow source.

  6. 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

  7. Martian seismicity. [from Viking data

    NASA Technical Reports Server (NTRS)

    Goins, N. R.; Lazarewicz, A. R.

    1979-01-01

    During the Viking mission to Mars, the seismometer on Lander II collected approximately 0.24 earth years of observational data, excluding periods of time dominated by wind-induced Lander vibration. The 'quiet-time' data set contains no confirmed seismic events. A proper assessment of the significance of this fact requires quantitative estimates of the expected detection rate of the Viking seismometer. The first step is to calculate the minimum magnitude event detectable at a given distance, including the effects of geometric spreading, anelastic attenuation, seismic signal duration, seismometer frequency response, and possible poor ground coupling. Assuming various numerical quantities and a Martian seismic activity comparable to that of intraplate earthquakes, the appropriate integral gives an expected annual detection rate of 10 events, nearly all of which are local. Thus only two to three events would be expected in the observational period presently on hand and the lack of observed events is not in gross contradiction to reasonable expectations. Given the same assumptions, a seismometer 20 times more sensitive than the present instrument would be expected to detect about 120 events annually.

  8. 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.

  9. Seasonal activity and morphological changes in martian gullies

    USGS Publications Warehouse

    Dundas, Colin M.; Diniega, Serina; Hansen, Candice J.; Byrne, Shane; McEwen, Alfred S.

    2012-01-01

    Recent studies of martian dune and non-dune gullies have suggested a seasonal control on present-day gully activity. The timing of current gully activity, especially activity involving the formation or modification of channels (which commonly have been taken as evidence of fluvial processes), has important implications regarding likely gully formation processes and necessary environmental conditions. In this study, we describe the results of frequent meter-scale monitoring of several active gully sites by the High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO). The aim is to better assess the scope and nature of current morphological changes and to provide improved constraints on timing of gully activity on both dune and non-dune slopes. Our observations indicate that (1) gully formation on Mars is ongoing today and (2) the most significant morphological changes are strongly associated with seasonal frost and defrosting activity. Observed changes include formation of all major components of typical gully landforms, although we have not observed alcove formation in coherent bedrock. These results reduce the need to invoke recent climate change or present-day groundwater seepage to explain the many martian gullies with pristine appearance.

  10. 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.

  11. 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.

  12. Characteristics of the Martian atmosphere surface layer

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    Researchers extend elements of various terrestrial boundary layer models to Mars in order to estimate sensible heat, latent heat, and momentum fluxes within the Martian atmospheric surface layer. To estimate the molecular viscosity and thermal conductivity of a CO2-H2O gas mixture under Martian conditions, parameterizations were developed. Parameterizations for specific heat and and binary diffusivity were also determined. The Prandtl and Schmidt numbers derived from these thermophysical properties were found to range from 0.78 - 1.0 and 0.47 - 0.70, respectively, for Mars. Brutsaert's 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 researchers modified the definition of the Monin-Obukhov length to properly account for the buoyancy forces arising from water vapor gradients in the Martian atmospheric boundary layer. This length scale was then utilized with similarity theory turbulent flux profiles with the same form as those used by Businger et al. and others. It was found that under most Martian conditions, the interfacial and surface sublayers offer roughly comparable resistance to sensible heat and water vapor transport and are thus both important in determining the associated fluxes.

  13. 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.

  14. Thermal Evolution and Crystallisation Regimes of the Martian Core

    NASA Astrophysics Data System (ADS)

    Davies, C. J.; Pommier, A.

    2015-12-01

    Though it is accepted that Mars has a sulfur-rich metallic core, its chemical and physical state as well as its time-evolution are still unconstrained and debated. Several lines of evidence indicate that an internal magnetic field was once generated on Mars and that this field decayed around 3.7-4.0 Gyrs ago. The standard model assumes that this field was produced by a thermal (and perhaps chemical) dynamo operating in the Martian core. We use this information to construct parameterized models of the Martian dynamo in order to place constraints on the thermochemical evolution of the Martian core, with particular focus on its crystallization regime. Considered compositions are in the FeS system, with S content ranging from ~10 and 16 wt%. Core radius, density and CMB pressure are varied within the errors provided by recent internal structure models that satisfy the available geodetic constraints (planetary mass, moment of inertia and tidal Love number). We also vary the melting curve and adiabat, CMB heat flow and thermal conductivity. Successful models are those that match the dynamo cessation time and fall within the bounds on present-day CMB temperature. The resulting suite of over 500 models suggest three possible crystallization regimes: growth of a solid inner core starting at the center of the planet; freezing and precipitation of solid iron (Fe- snow) from the core-mantle boundary (CMB); and freezing that begins midway through the core. Our analysis focuses on the effects of core properties that are expected to be constrained during the forthcoming Insight mission.

  15. 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.

  16. Martian external magnetic field proxies

    NASA Astrophysics Data System (ADS)

    Langlais, Benoit; Civet, Francois

    2015-04-01

    Mars possesses no dynamic magnetic field of internal origin as it is the case for the Earth or for Mercury. Instead Mars is characterized by an intense and localized magnetic field of crustal origin. This field is the result of past magnetization and demagnetization processes, and reflects its evolution. The Interplanetary Magnetic Field (IMF) interacts with Mars' ionized environment to create an external magnetic field. This external field is weak compared to lithospheric one but very dynamic, and may hamper the detailed analysis of the internal magnetic field at some places or times. Because there are currently no magnetic field measurements made at Mars' surface, it is not possible to directly monitor the external field temporal variability as it is done in Earth's ground magnetic observatories. In this study we examine to indirect ways of quantifying this external field. First we use the Advanced Composition Explorer (ACE) mission which measures the solar wind about one hour upstream of the bow-shock resulting from the interaction between the solar wind and the Earth's internal magnetic field. These measurements are extrapolated to Mars' position taking into account the orbital configurations of the Mars-Earth system and the velocity of particles carrying the IMF. Second we directly use Mars Global Surveyor magnetic field measurements to quantify the level of variability of the external field. We subtract from the measurements the internal field which is otherwise modeled, and bin the residuals first on a spatial and then on a temporal mesh. This allows to compute daily or semi daily index. We present a comparison of these two proxies and demonstrate their complementarity. We also illustrate our analysis by comparing our Martian external field proxies to terrestrial index at epochs of known strong activity. These proxies will especially be useful for upcoming magnetic field measurements made around or at the surface of Mars.

  17. Project APEX: Advanced manned exploration of the Martian moon Phobos

    NASA Technical Reports Server (NTRS)

    Eisley, Joe G.; Akers, Jim

    1992-01-01

    A preliminary design has been developed for a manned mission to the Martian moon Phobos. The spacecraft is to carry a crew of five and will be launched from Low Earth Orbit in the year 2010. The outbound trajectory to Mars uses a gravitational assisted swingby of Venus and takes eight months to complete. The stay at Phobos is scheduled for 60 days. During this time, the crew will be busily engaged in setting up a prototype fuel processing facility. The vehicle will then return to Earth orbit after a total mission duration of 656 days. The spacecraft is powered by three nuclear thermal rockets which also provide the primary electrical power via dual mode operation. The overall spacecraft length is 110 m, and the total mass departing from Low Earth Orbit is 900 metric tons.

  18. Dinosaur Day!

    ERIC Educational Resources Information Center

    Nakamura, Sandra; Baptiste, H. Prentice

    2006-01-01

    In this article, the authors describe how they capitalized on their first-grade students' love of dinosaurs by hosting a fun-filled Dinosaur Day in their classroom. On Dinosaur Day, students rotated through four dinosaur-related learning stations that integrated science content with art, language arts, math, and history in a fun and time-efficient…

  19. CEMI Days

    SciTech Connect

    2015-07-01

    CEMI Days are an important channel of engagement between DOE and the manufacturing industry to identify challenges and opportunities for increasing U.S. manufacturing competitiveness. CEMI Days that are held at manufacturing companies’ facilities can include tours of R&D operations or other points of interest determined by the host company.

  20. Day Care.

    ERIC Educational Resources Information Center

    Merro, John; And Others

    Interviews on the quality of day care in the United States are presented in this transcript of a program broadcast in the National Public Radio weekly series, "Options in Education." Writers, day care center personnel and others describe and evaluate the current situation. Federal legislation concerning children is examined, and researchers…

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. Did Martian Meteorites Come From These Sources?

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.

    2007-01-01

    Large rayed craters on Mars, not immediately obvious in visible light, have been identified in thermal infrared data obtained from the Thermal Emission Imaging System (THEMIS) onboard Mars Odyssey. Livio Tornabene (previously at the University of Tennessee, Knoxville and now at the University of Arizona, Tucson) and colleagues have mapped rayed craters primarily within young (Amazonian) volcanic plains in or near Elysium Planitia. They found that rays consist of numerous chains of secondary craters, their overlapping ejecta, and possibly primary ejecta from the source crater. Their work also suggests rayed craters may have formed preferentially in volatile-rich targets by oblique impacts. The physical details of the rayed craters and the target surfaces combined with current models of Martian meteorite delivery and cosmochemical analyses of Martian meteorites lead Tornabene and coauthors to conclude that these large rayed craters are plausible source regions for Martian meteorites.

  6. Material issues for lunar/Martian structures

    NASA Technical Reports Server (NTRS)

    Radford, Donald W.; Sadeh, Willy Z.; Cheng, Boyle C.

    1991-01-01

    Development of structures in the lunar/Martian environment depends upon the use of the most appropriate materials. Advanced composite materials are apparently the best candidates for use in structures on planetary surfaces and in space in view of their unique properties, tailorability and light weight. The physical and mechanical properties of advanced composite materials as related to their use in lunar/Martian structures are reviewed. Polymer matrix composites are recommended as the best materials in the first exploration stages of a lunar/Martian base. Increased use of ceramic and metal matrix composites is expected in the more advanced exploration stages. The pressing need for the development of tailored radiation shielding composite materials is discussed.

  7. Cosmogenic nuclides: Observable effects of Martian volatiles

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Drake, D. M.; Feldman, W. C.

    1988-01-01

    Cosmic-ray produced (cosmogenic) nuclides in returned Martian samples could be used to study the amounts and distributions of volatiles in the recent past on Mars. In planning for the gamma-ray spectrometer experiment that is scheduled to fly on the Mars Observer, many calculations were done on the nuclear reactions that should occur in the Martian surface, studying especially the production and transport of neutrons. It is found that three aspects of Mars can very significantly affect the production of cosmogenic products in Mars: the Martian atmosphere and the presence of H2O in or CO2 on the surface of Mars. These volatile components can greatly affect the energy and spatial distributions of neutrons, expecially those with thermal or near thermal energies, in the surface of Mars. In turn, these neutrons produce many cosmogenic nuclides that can be observed in samples returned from Mars.

  8. 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.

  9. Do oblique impacts produce Martian meteorites

    NASA Astrophysics Data System (ADS)

    Nyquist, L. E.

    1983-11-01

    It is pointed out that several achondritic meteorites, classified as shergottites, nakhlites, and chassignites, have a number of unusual characteristics. Following the suggestion of Wood and Ashwal (1981) these meteorites are collectively referred to as SNC meteorites. The major element compositions of the SNC meteorites are, in general, distinct from those of other meteorites and lunar samples, and similar to certain terrestrial rocks. The geochemical and geochronological characteristics of the SNC meteorites strongly imply that their parent body was on the order of lunar size or larger and geologically active. Serious attention must be given to the hypothesis of a Martian origin of the SNC meteorites and to dynamic processes capable of delivering Martian meteorites to earth. In connection with the present investigation, it is suggested that oblique impacts of large meteoroids can produce ejecta which is entrained with the ricocheting projectile and accelerated to velocities in excess of Martian escape velocity.

  10. 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.

  11. Extended survival of several organisms and amino acids under simulated martian surface conditions

    NASA Astrophysics Data System (ADS)

    Johnson, A. P.; Pratt, L. M.; Vishnivetskaya, T.; Pfiffner, S.; Bryan, R. A.; Dadachova, E.; Whyte, L.; Radtke, K.; Chan, E.; Tronick, S.; Borgonie, G.; Mancinelli, R. L.; Rothschild, L. J.; Rogoff, D. A.; Horikawa, D. D.; Onstott, T. C.

    2011-02-01

    Recent orbital and landed missions have provided substantial evidence for ancient liquid water on the martian surface as well as evidence of more recent sedimentary deposits formed by water and/or ice. These observations raise serious questions regarding an independent origin and evolution of life on Mars. Future missions seek to identify signs of extinct martian biota in the form of biomarkers or morphological characteristics, but the inherent danger of spacecraft-borne terrestrial life makes the possibility of forward contamination a serious threat not only to the life detection experiments, but also to any extant martian ecosystem. A variety of cold and desiccation-tolerant organisms were exposed to 40 days of simulated martian surface conditions while embedded within several centimeters of regolith simulant in order to ascertain the plausibility of such organisms' survival as a function of environmental parameters and burial depth. Relevant amino acid biomarkers associated with terrestrial life were also analyzed in order to understand the feasibility of detecting chemical evidence for previous biological activity. Results indicate that stresses due to desiccation and oxidation were the primary deterrent to organism survival, and that the effects of UV-associated damage, diurnal temperature variations, and reactive atmospheric species were minimal. Organisms with resistance to desiccation and radiation environments showed increased levels of survival after the experiment compared to organisms characterized as psychrotolerant. Amino acid analysis indicated the presence of an oxidation mechanism that migrated downward through the samples during the course of the experiment and likely represents the formation of various oxidizing species at mineral surfaces as water vapor diffused through the regolith. Current sterilization protocols may specifically select for organisms best adapted to survival at the martian surface, namely species that show tolerance to radical

  12. 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.

  13. 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

  14. 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.

  15. Ozone heating in the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard L.

    1991-01-01

    In addition to establishing that ozone constitutes a nonnegligible but only minor heat source in the Martian atmosphere, it is presently shown that the ozone abundance's hemispherical asymmetry is an improbable factor in the establishment of the polar caps' observed hemispherical asymmetry, since ozone absorbs less than 1 percent of the total solar flux incident on the polar caps. In the remaining hypothesized roles for Martian atmospheric ozone considered, namely those of cloud formation and snowfall, ozone heating remains nonnegligible but appears overstated by previous studies.

  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. Career Day

    NASA Video Gallery

    NASA's 2013 Career Days was a joint collaboration between NASA Langley and the Newport News Shipbuilding where 600 high school students from Virginia took on two design challenges -- designing a ca...

  18. Martian Soil Delivery to Analytical Instrument on Phoenix

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Robotic Arm of NASA's Phoenix Mars Lander released a sample of Martian soil onto a screened opening of the lander's Thermal and Evolved-Gas Analyzer (TEGA) during the 12th Martian day, or sol, since landing (June 6, 2008). TEGA did not confirm that any of the sample had passed through the screen.

    The Robotic Arm Camera took this image on Sol 12. Soil from the sample delivery is visible on the sloped surface of TEGA, which has a series of parallel doors. The two doors for the targeted cell of TEGA are the one positioned vertically, at far right, and the one partially open just to the left of that one. The soil between those two doors is resting on a screen designed to let fine particles through while keeping bigger ones Efrom clogging the interior of the instrument. Each door is about 10 centimeters (4 inches) long.

    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.

  19. Martian surface roughness and stratigraphy

    NASA Astrophysics Data System (ADS)

    Beyer, Ross Alan

    2004-12-01

    Orbital datasets can be combined and manipulated to learn about the three- dimensional structure of planetary surfaces, and the processes that have acted on them. The Mars Orbital Camera (MOC) is providing high-resolution images. These images allow qualitative inspection of features, and contain quantitative information about the shape of the surface. Using a photoclinometry technique derived from a lunar-Lambert photometric function, I am able to obtain estimates of the down-sun slope of each pixel in an image. This technique was calibrated against synthetic topography, compared to an area photoclinometry technique, and applied to the Viking and Pathfinder landing sites. It is a robust technique for obtaining the roughness and slope characteristics of large areas. It was applied to the potential landing sites for the Mars Exploration Rovers to evaluate site safety. The slopes from this point photoclinometry technique can be used to obtain a rough estimate of topography, which I used in a number of studies where topographic information was crucial. MOC images have shown that layering is pervasive on the martian surface. Mars Orbital Laser Altimeter (MOLA) data can be registered to MOC images to provide elevation constraints on layer outcrops. Such layers are observed in eastern Coprates Chasma both in the chasma rim and in a flat-topped massif. Observations indicate that the chasma stratigraphy consists of thin sequences of resistant layers and intervening thicker sequences of relatively less resistant layers. More resistant units cap the massif against erosion and result in steeper slopes than the weaker units would otherwise allow. These resistant layers can be used as stratigraphic markers which have allowed me to measure the subsidence and tilting of the massif relative to the chasma walls, providing evidence for tectonic motion in this portion of the Valles Marineris. These outcrops indicate that some of these layers may be analogus to terristrial flood

  20. 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

  1. 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.

  2. Oxygen in the Martian atmosphere: Regulation of PO2 by the deposition of iron formations on Mars

    NASA Technical Reports Server (NTRS)

    Burns, Roger G.

    1992-01-01

    During Earth's early history, and prior to the evolution of its present day oxygenated atmosphere, extensive iron rich siliceous sedimentary rocks were deposited, consisting of alternating layers of silica (chert) and iron oxide minerals (hematite and magnetite). The banding in iron formations recorded changes of atmosphere-hydrosphere interactions near sea level in the ancient ocean, which induced the oxidation of dissolved ferrous iron, precipitation of insoluble ferric oxides and silica, and regulation of oxygen in Earth's early atmosphere. Similarities between the Archean Earth and the composition of the present day atmosphere on Mars, together with the pervasive presence of ferric oxides in the Martian regolith suggest that iron formation might also have been deposited on Mars and influenced the oxygen content of the Martian atmosphere. Such a possibility is discussed here with a view to assessing whether the oxygen content of the Martian atmosphere has been regulated by the chemical precipitation of iron formations on Mars.

  3. M-DLS - a multichannel diode laser spectrometer for Martian studies

    NASA Astrophysics Data System (ADS)

    Vinogradov, Imant; Rodin, Alexander V.; Klimchuk, Artem

    A concept of Martian atmosphere and soil volatiles study was developed on the basis of diode laser spectroscopy by collaboration of IKI RAS, MIPT, GPI RAS, University of Reims (France), University of Cologne (Germany), and University of Edinburgh (Great Britain). An experiment, named as M-DLS, has been proposed for the stationery Landing Platform scientific payload of the ExoMars-2018 mission. The M-DLS instrument is targeted to long-term studies of: chemical and isotopic composition of atmosphere near the Martian surface, and its diurnal and seasonal variations; Martian soil volatiles at the location of the Landing Platform; integral chemical and isotopic composition of Martian atmosphere at low scales of altitude at the Landing Platform area, and its variations in respect to local time at the day-light; thermal and dynamic structure of the Martian atmosphere. The M-DLS studies are based on regular measurements of molecular absorption spectra in the IR range along several optical path trajectories, including: a suite of ICOS optical cells of up to 1 km effective optical path, which are directly linked to the ambient atmosphere; a capillary closed-volume optical cell, which is linked to pyrolytic output of a proposed MGAS instrument (Martian Gas Analytic Suite); direct Solar observation open atmosphere path of heterodyne measurements, which is co-directional with the open path line of sight of a proposed FAST instrument (Fourier spectrometer for Atmospheric Components and Temperature). The M-DLS measurements will be carried out in series of narrow-band 2 cm (-1) wide intervals with spectral resolution of 3 MHz ( 0.0001 cm (-1) ), providing for fine recording of molecular absorption line contours. By measurement of H _{2}O and CO _{2} molecules diurnal and seasonal variations and their isotope ratios D/H, (18) O/ (17) O/ (16) O, (13) C/ (12) C, of soil volatiles H _{2}S, NH _{3}, C _{2}H _{2} and others, we expect to receive data for specifying of physical and

  4. Argon isotopes as tracers for martian atmospheric loss

    NASA Astrophysics Data System (ADS)

    Slipski, Marek; Jakosky, Bruce M.

    2016-07-01

    Recent measurements of the present-day Ar abundance and isotopic ratios in the martian atmosphere by the SAM instrument suite onboard the Curiosity rover can be used to constrain the atmospheric and volatile evolution. We have examined the role of volcanic outgassing, escape to space via sputtering, crustal erosion, impact delivery, and impact erosion in reproducing the Ar isotope ratios from an initial state 4.4 billion years ago. To investigate the effects of each of these processes, their timing, and their intensity we have modeled exchanges of Ar isotopes between various reservoirs (mantle, crust, atmosphere, etc.) throughout Mars' history. Furthermore, we use present-day atmospheric measurements to determine the parameter space consistent with observations. We find that significant loss to space (at least 48% of atmospheric 36Ar) is required to match the observed 36Ar/38Ar ratio. Our estimates of volcanic outgassing do not supply sufficient 40Ar to the atmosphere to match observations, so in our model at least 31% of 40Ar produced in the crust must have also been released to the atmosphere. Of the total 40Ar introduced into the atmosphere about 25% must have been lost to space. By adding the present-day isotopic abundances with our results of total integrated Ar loss we find a "restored" value of atmospheric 40Ar/36Ar, which represents what that ratio would be if the total integrated Ar loss had remained in the atmosphere. We determine the restored value to be ∼900-1500. This is below the present martian atmospheric value (1900 ± 300), but 3-5 times greater than the terrestrial value.

  5. Some probable characteristics of the Martian regolith

    NASA Technical Reports Server (NTRS)

    King, Elbert A.

    1987-01-01

    A number of Mars surface environmental factors seriously affect the properties of the Martian regolith. The result is a regolith that is rather different from that of the moon. Some of the anticipated differences are discussed: weathering and lack of old glass; desert varnish; lack of micrometeorite impact products; abundance of meteorite fragments; and different grain size characteristics.

  6. 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.

  7. 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.

  8. The Chlorine Isotope Composition of Martian Meteorites

    NASA Astrophysics Data System (ADS)

    Sharp, Z. D.; Shearer, C. K.; Agee, C.; Burger, P. V.; McKeegan, K. D.

    2014-11-01

    The Cl isotope composition of martian meteorites range from -3.8 to +8.6 per mil. Ol-phyric shergottites are lightest; crustally contaminated samples are heaviest, basaltic shergottites are in-between. The system is explained as two component mixing.

  9. 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.

  10. 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.

  11. 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.

  12. Measurements of the Martian Gamma/Neutron Spectra with MSL/RAD

    NASA Astrophysics Data System (ADS)

    Kohler, J.; Zeitlin, C. J.; Ehresmann, B.; Wimmer-Schweingruber, R. F.; Hassler, D.; Reitz, G.; Brinza, D.; Weigle, E.; Boettcher, S.; Burmeister, S.; Guo, J.; Martin-Garcia, C.; Boehm, E.; Posner, A.; Rafkin, S. C.; Kortmann, O.

    2013-12-01

    The Radiation Assessment Detector (RAD) onboard Mars Science Laboratory's rover curiosity measures the energetic charged and neutral particle spectra and the radiation dose rate on the Martian surface. An important factor for determining the biological impact of the Martian surface radiation is the specific contribution of neutrons, which possess a high biological effectiveness. In contrast to charged particles, neutrons and gamma rays are generally only measured indirectly. Their measurement is the result of a complex convolution of the incident particle spectrum with the measurement process. We apply an inversion method to calculate the gamma/neutron spectra from the RAD neutral particle measurements. Here we show first measurements of the Martian gamma/neutron spectra and compare them to theoretical predictions. We find that the shape of the gamma spectrum is very similar to the predicted one, but with a ~50% higher intensity. The measured neutron spectrum agrees well with prediction up to ~100 MeV, but shows a considerably increased intensity for higher energies. The measured neutron spectrum translates into a radiation dose rate of 25 μGy/day and a dose equivalent rate of 106 μSv/day. This corresponds to 10% of the total surface dose rate, and 15% of the biological relevant surface dose equivalent rate on Mars. Measuring the Martian neutron spectra is an essential step for determining the mutagenic influences to past or present life at or beneath the Martian surface as well as the radiation hazard for future human exploration, including the shielding design of a potential habitat. The contribution of neutrons to the dose equivalent increases considerably with shielding thickness, so our measurements provide an important figure to mitigate cancer risk.

  13. Initiation and growth of martian ice lenses

    NASA Astrophysics Data System (ADS)

    Sizemore, Hanna G.; Zent, Aaron P.; Rempel, Alan W.

    2015-05-01

    Water ice in the upper meters of the martian regolith is a major volatile reservoir. Although the geographic extent, burial depth, and thermal stability of this shallow ice are well understood, its origin, history, and stratigraphy are not. Over the past decade, a growing body of observational evidence has indicated that shallow ground ice exceeds the pore volume of its host soil over large regions of both martian hemispheres. This is confounding, given that (1) the physical theory that accurately predicts the location of ground ice also assumes that ice should be pore-filling in the upper meter of regolith, and (2) the Phoenix spacecraft uncovered far more pore-filling ice than excess ice at its landing site in the northern hemisphere. The development of ice lenses by low-temperature in situ segregation - analogous to the processes that generate frost heave on Earth - has been hypothesized to explain shallow excess ice on Mars. We have developed a numerical model of ice lens initiation and growth in the martian environment, and used it to test this hypothesis for the first time. We carried out a large suite of numerical simulations in order to place quantitative constraints on the timing and location of ice lens initiation, and on the magnitude of ice lens growth in a variety of host soils. We find that ice lens initiation is a ubiquitous process in the martian high latitudes, but the ultimate magnitude of lens growth, or frost heave, is sensitive to the properties of the host soil. Depending on the specific properties of martian soils, in situ segregation may be a very slow process sufficient to explain the excess ice observed in the Dodo-Goldilocks trench at the Phoenix landing site, but without regionally significant effects. Alternatively, if clay-sized particles or perchlorate salts are present, in situ segregation may be a vigorous process that has significantly affected the stratigraphy of ground ice in the upper meter of regolith throughout the high

  14. 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.

  15. Characteristics of the Martian atmosphere surface layer

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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

  16. 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.

  17. 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

  18. Inspire Day

    ERIC Educational Resources Information Center

    Bohach, Barbara M.; Meade, Birgitta

    2014-01-01

    The authors collaborated on hosting a "Spring Inspire Day." planned and delivered by preservice elementary teachers as a social studies/science methods project. Projects that have authentic application opportunities can make learning meaningful for prospective teachers as well as elementary students. With the impetus for an integrated…

  19. Formation and Preservation of the Depleted and Enriched Shergottite Isotopic Reservoirs in a Convecting Martian Mantle

    NASA Technical Reports Server (NTRS)

    Kiefer, Walter S.; Jones, John H.

    2015-01-01

    There is compelling isotopic and crater density evidence for geologically recent volcanism on Mars, in the last 100-200 million years and possibly in the last 50 million years. This volcanism is due to adiabatic decompression melting and thus requires some type of present-day convective upwelling in the martian mantle. On the other hand, martian meteorites preserve evidence for at least 3 distinct radiogenic isotopic reservoirs. Anomalies in short-lived isotopic systems (Sm-146, Nd-142, Hf-182, W-182) require that these reservoirs must have developed in the first 50 to 100 million years of Solar System history. The long-term preservation of chemically distinct reservoirs has sometimes been interpreted as evidence for the absence of mantle convection and convective mixing on Mars for most of martian history, a conclusion which is at odds with the evidence for young volcanism. This apparent paradox can be resolved by recognizing that a variety of processes, including both inefficient mantle mixing and geographic separation of isotopic reservoirs, may preserve isotopic heterogeneity on Mars in an actively convecting mantle. Here, we focus on the formation and preservation of the depleted and enriched isotopic and trace element reservoirs in the shergottites. In particular, we explore the possible roles of processes such as chemical diffusion and metasomatism in dikes and magma chambers for creating the isotopically enriched shergottites. We also consider processes that may preserve the enriched reservoir against convective mixing for most of martian history.

  20. 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.

  1. Rover's Wheel Churns Up Bright Martian Soil (Vertical)

    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.

    The image is presented here as a vertical projection, as if looking straight down, and in false color, which brings out subtle color differences.

  2. Rover's Wheel Churns Up Bright Martian Soil (False Color)

    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.

    The image is presented here in false color that is used to bring out subtle differences in color.

  3. Rover's Wheel Churns Up Bright Martian Soil (Stereo)

    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.

    Multiple images taken with Spirit's panoramic camera are combined here into a stereo view that appears three-dimensional when seen through red-blue glasses, with the red lens on the left.

  4. Conductivity Probe Inserted in Martian Soil, Sol 46

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander shows the lander's Thermal and Electrical Conductivity Probe (TECP), at the end of the Robotic Arm, on the 46th Martian day, or sol, of the mission (July 11, 2008).

    The TECP is inserted at a site called Vestri, which was monitored several times over the course of the mission. The probe's measurements at this site yielded evidence that water was exchanged, daily and seasonally, between the soil and atmosphere.

    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.

  5. Origin and Reactivity of the Martian Soil: A 2003 Micromission

    NASA Technical Reports Server (NTRS)

    Yen, Albert S.; Kim, S. Sam; Marshall, John; Murray, Bruce C.

    1999-01-01

    The role of water in the development of the martian surface remains a fundamental scientific question. Did Mars have one or more "warm and wet" climatic episodes where liquid water was stable at the surface? If so, the mineral phases present in the soils should be consistent with a history of aqueous weathering. More generally, the formation of hydrated mineral phases on Mars is a strong indicator of past habitable surface environments. The primary purpose of this investigation is to help resolve the question of whether such aqueous indicators are present on Mars by probing the upper meter for diagnostic mineral species. According to Burns [1993], the formation of the ferric oxides responsible for the visible color of Mars are the result of dissolution of Fe (+2) phases from basalts followed by aqueous oxidation and precipitation of Fe" mineral assemblages. These precipitates likely included iron oxyhydroxides such as goethite (a-FeOOH) and lepidocrocite (g-FeOOH), but convincing evidence for these phases at the surface is still absent. The stability of these minerals is enhanced beneath the surface, and thus we propose a subsurface search for hydroxylated iron species as a test for a large-scale chemical weathering process based on interactions with liquid water. It is also possible that the ferric minerals on Mars are not aqueous alteration products of the rocks. A chemical study of the Pathfinder landing site concluded that the soils are not directly derived from the surrounding rocks and are enhanced in Mg and Fe. The additional source of these elements might be from other regions of Mars and transported by winds, or alternatively, from exogenic sources. Gibson [1970] proposed that the spectral reflectivity of Mars is consistent with oxidized meteoritic material. Yen and Murray [1998] further extend Gibson's idea and show, in the laboratory, that metallic iron can be readily oxidized to maghemite and hematite under present-day martian surface conditions (in the

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

    NASA Astrophysics Data System (ADS)

    Chicarro, A. F.

    2005-12-01

    processes. The UV and IR Atmospheric Spectrometer (SPICAM) has provided the first complete vertical profile of CO2 density and temperature, and has simultaneously meas-ured the distribution of water vapour and ozone. The Energetic Neutral Atoms Analyser (ASPERA) has identified the solar wind interaction with the upper atmosphere and has measured the properties of the planetary wind in the Mars tail. The Radio Science Experiment (MaRS) has studied for the first time the surface roughness by pointing the spacecraft high-gain antenna to the Martian surface, which reflects the signal before sending it to Earth. Also, the martian interior has been probed by studying the gravity anomalies affecting the orbit due to mass variations of the crust. Finally, preliminary results of the subsur-face sounding radar (MARSIS) indicate strong echoes coming from the surface but lack of echoes under the young smooth Northern plains, which may indicate the presence of thick and homogeneous plains deposits. Water is the unifying theme of the mission to be studied by all instruments using different techniques. Mars Express is already hinting at a quantum leap in our understanding of the planet's geological evolu-tion, to be complemented by the ground truth being provided by the American MER rovers. The nominal lifetime of the orbiter spacecraft is of one Martian year (687 days), potentially to be ex-tended by another Martian year to complete global coverage and observe all seasons twice. Mars Express is the first European mission to another planet.

  7. 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

  8. Valentine's Day

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02174 Valentine's Day

    This isolated mesa [lower left center of the image] has an almost heart-shaped margin. Happy Valentine's Day from Mars.

    Image information: VIS instrument. Latitude 29.4N, Longitude 79.1E. 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. 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.

  10. 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.

  11. Schroeter's ratios for Martian craters - Radar results

    NASA Astrophysics Data System (ADS)

    Roth, L. E.

    1991-01-01

    Schroeter's ratios (ratios of the rim volume to the apparent volume) are determined for a sample of 29 large, degraded Martian craters selected from the Goldstone Mars radar altimetry data. On the average, the values of the calculated Schroeter's ratios are about two orders of magnitude smaller than the same ratios for fresh lunar craters. This indicates a severe rim volume deficit in degraded Martian craters and it provides an additional support to the notion of a widespread resurfacing of intercrater plains on Mars. Schroeter's ratios for degraded craters could provide a semi-quantitative measure of the effects of the modification processes that had been active on Mars and on the other planetary bodies.

  12. Dayside temperatures of the Martian upper atmosphere

    NASA Astrophysics Data System (ADS)

    Bittner, Hermann; Fricke, K. H.

    1987-11-01

    One central problem in understanding the Martian upper atmosphere is the poor correlation between exospheric temperatures and the energy input from the Sun in the EUV and UV. Turbulence heats the atmosphere by dissipation of turbulent energy and cools it by downward heat transport. A time-variable turbulence may introduce a stochastic component in addition to the solar-driven, regular variation of the exospheric temperatures. To investigate the possible range of temperatures on the basis of this assumption, the authors develop a one-dimensional mean-dayside model of the energy balance of the Martian upper atmosphere. With plausible assumptions on the range of the eddy diffusion coefficient, they find a stochastic component of ±63K for the exospheric temperatures. The comparison of observed data with the results of their model yields a best value for the efficiency of the heating by absorption of solar ultraviolet radiation of 0.145±0.05.

  13. Overview of the Martian radiation environment experiment

    NASA Technical Reports Server (NTRS)

    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. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Martian lake basins and lacustrine plains

    NASA Astrophysics Data System (ADS)

    de Hon, R. A.

    1992-02-01

    A classification of Martian lake basins based on the location of the basin in respect to water sources is proposed. The classes are type 1: valley-head basins; type 2: intravalley basins; type 3: valley-terminal basins; and type 4: isolated basins. Martian lakes are ephemeral features. Many craters and irregular depressions impounded water only until the basins filled and overflowed. Water escaping by spillover rapidly cut crevasses in the downstream side of basins and drained the ponds. Clastic lacustrine sediments collected in the lakes as flowing water lost velocity and turbulence. Evaporitic deposits may be significant in those basins that were not rapidly drained. Sediments deposited in lake basins form smooth, featureless plains. Lacustrine plains are potentially candidate sites for Mars landings and for the search for evidence of ancient life.

  19. 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.

  20. 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

  1. 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.

  2. Biogenic Magnetite in Martian Meteorite ALH84001

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, Kathie L.; Bazylinski, Dennis; Wentworth, Susan J.; McKay, David S.; Kirschvink, Joseph L.; Clemett, Simon J.; Bell, Mary Sue; Golden, D. C.

    1999-01-01

    Fine-grained magnetite (Fe3O4) in martian meteorite ALH84001, generally less than 200 microns in size, is located primarily in the rims that surround the carbonate globules. There are two populations of ALH84001 magnets, which are likely formed at low temperature by inorganic and biogenic processes. Nearly 27/o of ALH84001 magnetite particles. also called elongated prisms, have characteristics which make them uniquely identifiable as biological precipitates.

  3. Biogenic Magnetite in Martian Meteorite ALH84001

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, K. L.; Bazylinski, Dennis; Wentworth, Susan J.; McKay, David S.; Kirschvink, Joseph L.; Clemett, SImon J.; Bell, Mary Sue; Golden, D. C.; Gibson, Everett K., Jr.

    1999-01-01

    Fine-grained magnetite (Fe3O4) in martian meteorite ALH84001, generally less than 200 nm in size, is located primarily in the rims that surround the carbonate globules. There are two populations of ALH84001 magnetites, which are likely formed at low temperature by inorganic and biogenic processes. Nearly 27% of ALH84001 magnetite particles, also called elongated prisms, have characteristics which make them uniquely identifiable as biological precipitates. Additional information is contained in the original extended abstract.

  4. Scaling relations for large Martian valleys

    NASA Astrophysics Data System (ADS)

    Som, Sanjoy M.; Montgomery, David R.; Greenberg, Harvey M.

    2009-02-01

    The dendritic morphology of Martian valley networks, particularly in the Noachian highlands, has long been argued to imply a warmer, wetter early Martian climate, but the character and extent of this period remains controversial. We analyzed scaling relations for the 10 large valley systems incised in terrain of various ages, resolvable using the Mars Orbiter Laser Altimeter (MOLA) and the Thermal Emission Imaging System (THEMIS). Four of the valleys originate in point sources with negligible contributions from tributaries, three are very poorly dissected with a few large tributaries separated by long uninterrupted trunks, and three exhibit the dendritic, branching morphology typical of terrestrial channel networks. We generated width-area and slope-area relationships for each because these relations are identified as either theoretically predicted or robust terrestrial empiricisms for graded precipitation-fed, perennial channels. We also generated distance-area relationships (Hack's law) because they similarly represent robust characteristics of terrestrial channels (whether perennial or ephemeral). We find that the studied Martian valleys, even the dendritic ones, do not satisfy those empiricisms. On Mars, the width-area scaling exponent b of -0.7-4.7 contrasts with values of 0.3-0.6 typical of terrestrial channels; the slope-area scaling exponent $\\theta$ ranges from -25.6-5.5, whereas values of 0.3-0.5 are typical on Earth; the length-area, or Hack's exponent n ranges from 0.47 to 19.2, while values of 0.5-0.6 are found on Earth. None of the valleys analyzed satisfy all three relations typical of terrestrial perennial channels. As such, our analysis supports the hypotheses that ephemeral and/or immature channel morphologies provide the closest terrestrial analogs to the dendritic networks on Mars, and point source discharges provide terrestrial analogs best suited to describe the other large Martian valleys.

  5. MetNet - Martian Network Mission

    NASA Astrophysics Data System (ADS)

    Harri, A.-M.

    2009-04-01

    We are developing a new kind of planetary exploration mission for Mars - MetNet in situ observation network based on a new semi-hard landing vehicle called the Met-Net Lander (MNL). The actual practical mission development work started in January 2009 with participation from various countries and space agencies. The scientific rationale and goals as well as key mission solutions will be discussed. The eventual scope of the MetNet Mission is to deploy some 20 MNLs on the Martian surface using inflatable descent system structures, which will be supported by observations from the orbit around Mars. Currently we are working on the MetNet Mars Precursor Mission (MMPM) to deploy one MetNet Lander to Mars in the 2009/2011 launch window as a technology and science demonstration mission. The MNL will have a versatile science payload focused on the atmospheric science of Mars. Detailed characterization of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatology cycles, require simultaneous in-situ measurements by a network of observation posts on the Martian surface. The scientific payload of the MetNet Mission encompasses separate instrument packages for the atmospheric entry and descent phase and for the surface operation phase. The MetNet mission concept and key probe technologies have been developed and the critical subsystems have been qualified to meet the Martian environmental and functional conditions. This development effort has been fulfilled in collaboration between the Finnish Meteorological Institute (FMI), the Russian Lavoschkin Association (LA) and the Russian Space Research Institute (IKI) since August 2001. Currently the INTA (Instituto Nacional de Técnica Aeroespacial) from Spain is also participating in the MetNet payload development.

  6. Modelling the martian cosmic radiation environment

    NASA Astrophysics Data System (ADS)

    Dartnell, L. R.; Desorgher, L.; Ward, J. M.; Coates, A. J.

    2013-09-01

    The martian surface is no longer protected by a global magnetic field or substantial atmosphere and so is essentially unshielded to the flux of cosmic rays. This creates an ionising radiation field on the surface and subsurface that is hazardous to life and the operation of spacecraft instruments. Here we report the modelling approach used to characterise this complex and time-variable radiation environment and discuss the wider applications of the results generated.

  7. 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

  8. Effect of Shadowing on Survival of Bacteria under Conditions Simulating the Martian Atmosphere and UV Radiation▿ †

    PubMed Central

    Osman, Shariff; Peeters, Zan; La Duc, Myron T.; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri

    2008-01-01

    Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-μm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-μm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (∼5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars. PMID:18083857

  9. 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

  10. Hydrology day

    NASA Astrophysics Data System (ADS)

    Morel-Seytoux, H. J.

    Registration for the Hydrology Day sponsored by the Front Range Branch of AGU on April 23 at Colorado State University in Fort Collins, Colorado, totaled 121 participants, of whom 61 were students.Thirty-one individuals joined the Front Range Branch. Three students from Colorado State University won the awards for best paper in their category: Thomas W. Anzia (Sr.), ‘A Comprehensive Table of Standard Deviates for Confidence Limits on Extreme Events’ Victor Nazareth (M.S.), ‘Aquifer Properties from Single-Hole Aquifer Tests’ and Roy W. Koch (Ph.D.), ‘A Physically Based Derivation of the Distribution of Excess Precipitation.’ Judges for the awards were Dr. Bittinger, Resource Consultants, Fort Collins; George Leavesley and Daniel Bauer, USGS, Water Resources Division, Denver; Scott Tucker, Executive Director, Denver Urban Drainage and Flood Control District; Charles Brendecke, Department of Civil Engineering, Univ. of Colorado, Boulder.

  11. 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.

  12. 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.

  13. Photochemical instability of the ancient Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Zahnle, Kevin; Haberle, Robert M.; Catling, David C.; Kasting, James F.

    2008-11-01

    We develop a 1-D steady state photochemical model of the modern Martian atmosphere and apply it to possible Martian atmospheres present and past. A unique feature of our model is that the major current sink of oxygen is dry deposition (surface reactions) of highly reactive, oxidized molecules (chiefly H2O2), rather than oxygen escape to space. Another difference is that we allow hydrogen to escape to space at the diffusion limit, which gives H escape fluxes ~70% higher than in other models. What results is a model with one free parameter: a dry deposition velocity to describe the surface sink of reactive molecules. An effective global average deposition velocity of 0.02 cm s-1 for H2O2 and O3 gives a good match to the observed abundances of O2, CO, and H2, the three abundant photochemical trace gases. We then apply our model to Martian atmospheres with different amounts of CO2, H2O, and solar forcing. We find that thick, cold, dry CO2 atmospheres are photochemically unstable with respect to conversion to CO. This may be pertinent to ancient Mars when the Sun was faint and O escape rates were likely high, for which the tipping point is computed to be ~10 mbar of CO2. The possible photochemical instability of cold thick CO2 atmospheres, and the high likelihood that CO was abundant even if CO2 were stable, has broad implications for early Mars.

  14. 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.

  15. A Mobility Concept for Martian Exploration

    NASA Technical Reports Server (NTRS)

    Costes, Nicholas; Sture, Stein

    1998-01-01

    Soil mechanics and geological investigations on Mars or on the Moon are described herein, using a novel mobility system, designated as the "Elastic Loop Mobility System (ELMS)". ELMS was developed as a spin-off of the U. S. Lunar Roving Vehicle (LRV) which operated on the Moon during the Apollo 15, 16, and 17 Missions. Extensive testing of the ELMS, both on soft soil and on rigid obstacles, has shown that the ELMS outperforms by far both the LRV and the two manned, self-propelled Soviet rovers, Lunokhod 1 and 2, which landed on the Moon in the western part of Mare Imbrium, aboard the spacecraft Luna 17 and 21. In this paper, examples of soil mechanics and geological investigations that can be conducted either by an unmanned, self-propelled ELMS rover, or by an ELMS attached to a Martian Lander are discussed, along with the associated instrumentation. Through such investigations, ascertaining the existence of some primitive forms of past or present life on Martian or Lunar geological formations may become possible, in addition to obtaining numerous data on the mechanical and physico-chemical properties of Martian or Lunar soils along long traverses.

  16. Terrestrial Analog Studies for Martian Patterned Ground

    NASA Technical Reports Server (NTRS)

    Rossbacher, L. A.

    1985-01-01

    A recurring problem in understanding Martian patterned ground is explaining its large size. Terrestrial patterned ground in Swedish Lapland offers an analog that may help explain this. In cold, arid regions with strong winds, polygonal features are accentuated paralled to the dominant wind direction. Preliminary results of a comparison between Martian polygonal troughs and dominant wind directions suggests a good correlation. This evolutionary model involving aeolian modification of Martian polygonal ground helps explain the large size features without requiring multiple, deep freeze-thaw cycles. A well-established geographical technique, nearest neighbor analysis, can be modified and applied to the distribution of patterned ground on Earth and Mars. The procedure determines the R-statistic, which reflects the degree to which on observation departs from an expected random pattern. The R-statistic is independent of scale, and therefore it can be applied to any size of type of pattern. Preliminary results indicate that there may be a correlation between the R-statistic and the process that create the polygons.

  17. 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?

  18. 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.

  19. Periglacial and glacial analogs for Martian landforms

    NASA Astrophysics Data System (ADS)

    Rossbacher, Lisa A.

    1992-12-01

    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.

  20. 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.

  1. 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.

  2. 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.

  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. 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.

  5. 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

  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. A Martian analog in Kansas: Comparing Martian strata with Permian acid saline lake deposits

    NASA Astrophysics Data System (ADS)

    Benison, Kathleen C.

    2006-05-01

    An important result of the Mars Exploration Rover's (MER) mission has been the images of sedimentary structures and diagenetic features in the Burns Formation at Meridiani Planum. Bedding, cross-bedding, ripple marks, mud cracks, displacive evaporite crystal molds, and hematite concretions are contained in these Martian strata. Together, these features are evidence of past saline groundwater and ephemeral shallow surface waters on Mars. Geochemical analyses of these Martian outcrops have established the presence of sulfates, iron oxides, and jarosite, which strongly suggests that these waters were also acidic. The same assemblage of sedimentary structures and diagenetic features is found in the salt-bearing terrestrial red sandstones and shales of the middle Permian (ca. 270 Ma) Nippewalla Group of Kansas, which were deposited in and around acid saline ephemeral lakes. These striking sedimentological and mineralogical similarities make these Permian red beds and evaporites the best-known terrestrial analog for the Martian sedimentary rocks at Meridiani Planum.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. Spectroscopic Identification of Carbonate Minerals in the Martian Dust

    NASA Astrophysics Data System (ADS)

    Bandfield, Joshua L.; Glotch, Timothy D.; Christensen, Philip R.

    2003-08-01

    Thermal infrared spectra of the martian surface indicate the presence of small concentrations (~2 to 5 weight %) of carbonates, specifically dominated by magnesite (MgCO3). The carbonates are widely distributed in the martian dust, and there is no indication of a concentrated source. The presence of small concentrations of carbonate minerals in the surface dust and in martian meteorites can sequester several bars of atmospheric carbon dioxide and may have been an important sink for a thicker carbon dioxide atmosphere in the martian past.

  13. Tides in the Martian atmosphere, and other topics

    NASA Astrophysics Data System (ADS)

    Withers, Paul Gareth

    2003-11-01

    The dynamics of the martian upper atmosphere are not well-understood. I have identified the dominant tidal modes present in the upper atmosphere by comparing density measurements from the aerobraking of the Mars Global Surveyor spacecraft to predictions from classical tidal theory. Other observations and general circulation models have also provided constraints. I have presented a justification for why topography has a strong influence on the tides in the upper atmosphere. I have also studied sol-to-sol variations in density at fixed altitude, latitude, longitude, season, and time of day. I have developed a novel “Balanced Arch” technique to derive pressures and temperature from these density measurements that also estimates the zonal wind speed in the atmosphere. These are the first measurements of winds in the martian upper atmosphere. This technique can also be applied to anticipated data from Titan to measure winds in its upper atmosphere. I have developed techniques to derive density, pressure, and temperature profiles from entry accelerometer data, used them to investigate the entry of Mars Pathfinder, and discovered that surprisingly accurate temperature profiles can be derived without using any aerodynamic information at all. I have also investigated techniques to derive atmospheric properties from the Doppler shift in telemetry from a spacecraft during atmospheric entry and found that a surprisingly robust estimate of temperature at peak acceleration can be derived. I have discovered a network of tectonic ridges in the otherwise bland northern plains of Mars and studied their implications for a possible ocean in that area. I have tested the hypothesis that the formation of lunar crater Giordano Bruno was witnessed in 1178 AD and rejected it due to the lack of any observations of the immense meteor storm that must have followed the crater's formation.

  14. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2012-07-01 2012-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  15. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2010-07-01 2010-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  16. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2014-07-01 2013-07-01 true Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  17. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2011-07-01 2010-07-01 true Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  18. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2013-07-01 2013-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  19. Marvin: MARtian Vehicular INvestigator A Proposal for a Long-Range Pressurized Rover

    NASA Astrophysics Data System (ADS)

    1999-01-01

    NASA is planning manned missions to Mars in the near future. In order to fully exploit the available time on the surface for exploration, a roving vehicle is necessary. A nine-member student design team from the Wichita State University Department of Aerospace Engineering developed the MARtian Vehicular INvestigator (MARVIN) a manned, pressurized, long distance rover. In order to meet the unique requirements for successful operation in the harsh Martian environment a four wheeled, rover was designed with a composite pressure vessel six meters long and 2.5 meters in diameter. The rover is powered by twin proton exchange membrane fuel cells which provide electricity to the drive motors and onboard systems. The MARVIN concept is expected to have a 1500 km range with a maximum speed of 25 km/hr and a 14-day endurance.

  20. Animated Optical Microscope Zoom in from Phoenix Launch to Martian Surface

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This animated camera view zooms in from NASA's Phoenix Mars Lander launch site all the way to Phoenix's Microscopy and Electrochemistry and C Eonductivity Analyzer (MECA) aboard the spacecraft on the Martian surface. The final frame shows the soil sample delivered to MECA as viewed through the Optical Microscope (OM) on Sol 17 (June 11, 2008), or the 17th Martian day.

    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.

  1. A numerical circulation model with topography for the Martian Southern Hemisphere

    NASA Technical Reports Server (NTRS)

    Mass, C.; Sagan, C.

    1975-01-01

    A quasi-geostrophic numerical model, including friction, radiation, and the observed planetary topography, is applied to the general circulation of the Martian atmosphere in the Southern Hemisphere at latitudes south of about 35 deg. Near equilibrium weather systems developed after about 5 model days. To avoid violating the quasi-geostrophic approximation, only 0.8 of the already smoothed relief was employed. Weather systems and velocity fields are strikingly tied to topography. A 2mb middle latitude jet stream is found of remarkably terrestrial aspect. Highest surface velocities, both horizontal and vertical, are predicted in western Hellas Planitia and eastern Argyre Planitia, which are observed to be preferred sites of origin of major Martian dust storms. Mean horizontal velocities and vertical velocities are found just above the surface velocity boundary layer.

  2. Martian Clouds Pass By on a Winter Afternoon

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Opportunity captured a view of wispy afternoon clouds, not unlike fair weather clouds on Earth, passing overhead on the rover's 956th sol, or Martian day (Oct. 2, 2006). With Opportunity facing northeast, the clouds appear to drift gently toward the west in this movie taken with the rover's navigation camera.

    The 10 frames, taken 32 seconds apart, show the formation and evolution of what are likely mid-level, convective water clouds. Such clouds are common near Mars' equator at this time of the Martian year. They have been observed by both of NASA's Mars Exploration Rovers, by satellites orbiting Mars, and by the Hubble Space Telescope. In this case, the clouds appear to develop at a fixed location, in the center of the frame about 25 degrees above the horizon. This style of origin suggests that a thermal plume is rising over a surface feature. In spite of apparent winds aloft, the thermal plume appears to remain stationary for the 5-minute duration of the movie.

    Though scientists have determined from the images that the wind bearing is east-northeast, approximately 80 degrees, it is not possible on the basis of the movie to unambiguously determine the height and speed of the clouds. Scientists estimate, based on models of atmospheric wind profiles and the apparent displacement of the clouds, that all of the clouds in the movie are at about the same height somewhere between 5 kilometers and 25 kilometers (3 to 20 miles) above the surface. The clouds are estimated to be moving at 2.5 meters per second, if they are low, to 12.5 meters per second, if they are high (8 feet per second to 41 feet per second).

    Like clouds on Earth, these Martian clouds are probably composed of ice crystals and possibly supercooled water droplets. They are similar in appearance to terrestrial cirrocumulus or high altocumulus clouds. On Earth, such clouds are relatively transient and consist of small, individual cloudlets arranged in rippled

  3. 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.

  4. 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

  5. Constraints on Mantle Plume Melting Conditions in the Martian Mantle Based on Improved Melting Phase Relationships of Olivine-Phyric Shergottite Yamato 980459

    NASA Technical Reports Server (NTRS)

    Kiefer, Walter S.; Rapp, Jennifer F.; Usui, Tomohiro; Draper, David S.; Filiberto, Justin

    2016-01-01

    Martian meteorite Yamato 980459 (hereafter Y98) is an olivine-phyric shergottite that has been interpreted as closely approximating a martian mantle melt [1-4], making it an important constraint on adiabatic decompression melting models. It has long been recognized that low pressure melting of the Y98 composition occurs at extremely high temperatures relative to martian basalts (1430 degC at 1 bar), which caused great difficulties in a previous attempt to explain Y98 magma generation via a mantle plume model [2]. However, previous studies of the phase diagram were limited to pressures of 2 GPa and less [2, 5], whereas decompression melting in the present-day martian mantle occurs at pressures of 3-7 GPa, with the shallow boundary of the melt production zone occurring just below the base of the thermal lithosphere [6]. Recent experimental work has now extended our knowledge of the Y98 melting phase relationships to 8 GPa. In light of this improved petrological knowledge, we are therefore reassessing the constraints that Y98 imposes on melting conditions in martian mantle plumes. Two recently discovered olivine- phyric shergottites, Northwest Africa (NWA) 5789 and NWA 6234, may also be primary melts from the martian mantle [7, 8]. However, these latter meteorites have not been the subject of detailed experimental petrology studies, so we focus here on Y98.

  6. Daily and seasonal Viking observations of Martian bore wave systems

    NASA Technical Reports Server (NTRS)

    Hunt, G. E.; Pickersgill, A. O.; James, P. B.; Evans, N.

    1981-01-01

    A Martian atmospheric phenomenon called a bore wave has been observed by the Viking imaging system during late spring and early summer of two Martian years, in the Tharsis Ridge region of the planet. The observational data are presented, and a tentative explanation is offered for the occurrence of this feature, formed by airflow and which behaves like a thermally induced diurnal katabatic breeze.

  7. Martian Cratering 4: Mariner 9 Initial Analysis of Cratering Chronology

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.

    1973-01-01

    Early analyses of cratering and other Martian surface properties that indicated extensive ancient erosion have been strongly supported by Mariner 9 data. By their great variations in density, these craters indicate a history of Martian erosion and crustal development intermediate between earth and the moon.

  8. 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.

  9. 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…

  10. Aerobraking in a dusty Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Chang, I-Dee; Tauber, Michael; Papadopoulos, Periklis

    1990-01-01

    The effects of dust particle impacts on the erosion of the heat shield were estimated for a 26 m diameter aerobraking vehicle entering the Mars atmosphere at 8.6 km/sec. An explicit Navier-Stokes code was used to compute the flow field about the vehicle for the actual Martian atmospheric composition at a speed of 7.5 km/sec. The deceleration and melting of the dust particles within the forebody shock-layer was computed for dust spherules having initial diameters from 3 to 10 microns. Two heat shield materials were considered: Shuttle tiles with glassy surfaces and a low-density ablator known as Avcoat.

  11. Moessbauer Spectroscopy on the Martian Surface: Predictions

    NASA Technical Reports Server (NTRS)

    Schaefer, M. W.; Dyar, M. D.

    2003-01-01

    Moessbauer spectrometers will be used on the upcoming MER/Athena and Mars Express/ Beagle 2 landers to identify and quantify relative amounts of iron-bearing minerals and determine Fe3+/Fe2+ ratios, allowing more realistic modeling of Martian mineralogy and geochemistry. To properly interpret the spectra acquired by these instruments, we must understand the Mossbauer parameters of minerals that we might expect to find on Mars. We present here a summary of predicted Fe-bearing minerals that might be observed by the MER Moessbauer spectrometers, based upon previous and our own on-going work.

  12. 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.

  13. Differential degradation of Martian impact basins

    NASA Technical Reports Server (NTRS)

    Stam, M.

    1984-01-01

    Among the major problems of martian geologic history are the cause of the highland-lowland dichotomy, and of the scarp separating these two global-scale provinces. These features were formed after much of the early bombardment was completed; consequently, many of the surviving impact basins very likely were present during the creation of the dichotomy, and it is possible that differences in their present morphologies as a function of location and of relative age may provide clues to the tectonic and geomorphic processes responsible for the dichotomy and the scarp.

  14. Release of volatiles from possible Martian analogs

    NASA Technical Reports Server (NTRS)

    Kotra, R. K.; Gibson, E. K.; Urbancic, M. A.

    1982-01-01

    Viking data suggest the presence of volatile-rich materials in the Martian regolith. The thermal stabilities of mineral phases and their volatile release profiles were studied in detail in our laboratory. Thermal analysis, combined with mass spectrometry, was applied to the study of the behavior of carbonates, sulfates, hydrates, and clays. The results indicate that these techniques are useful in the preliminary mineralogical characterizations of volatile-rich minerals. However, our results also indicate that great care must be taken in the incorporation into planetary probes of such methods as hearing rates, pressure, composition of atmospheres, grain size, etc., because these factors effect volatile release.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Mars Scout: Micromissions to Investigate Martian Environments

    NASA Technical Reports Server (NTRS)

    Cabrol, N. A.; Ori, G. G.; Grin, E. A.; Sims, M. H.; Marinangeli, L.; McKay, C.; Marshall, J.; Thomas, H.; Rabbette, M.; Landheim, R.

    2000-01-01

    Environments can be local, regional, or global. They can include one or more geological, morphological, climatological, and biological types. An environment also represents all the interactions that take place in the identified boundaries. Current planned missions to Mars in the Surveyor Program assume a good knowledge of the Martian environment that we do not have because it cannot be obtained only from orbit. There is a missing step between orbital data and the complex Surveyor missions to be landed that needs to be filled. The Ames/IRSPS Scout Mission Concept originally proposed in February 1999 filled this gap by landing a series of small (less than 10 kgs. each) scout missions. The Mars Environment Scout Mission Concept is being developed to explore the possibility of sending a series of small, simple, and inexpensive stations to the surface of Mars. The objective(s) would be to document either: (a) the environmental diversity of Mars, (b) a specific Martian environment, and/or (c) a region of interest. This type of mission will provide critical information about environments that is currently not available, and could also be used as precursors helping the design, preparation, and planning of more complex future missions to come.

  6. Martian cratering. II - Asteroid impact history.

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.

    1971-01-01

    This paper considers the extent to which Martian craters can be explained by considering asteroidal impact. Sections I, II, and III of this paper derive the diameter distribution of hypothetical asteroidal craters on Mars from recent Palomar-Leiden asteroid statistics and show that the observed Martian craters correspond to a bombardment by roughly 100 times the present number of Mars-crossing asteroids. Section IV discusses the early bombardment history of Mars, based on the capture theory of Opik and probable orbital parameters of early planetesimals. These results show that the visible craters and surface of Mars should not be identified with the initial, accreted surface. A backward extrapolation of the impact rates based on surviving Mars-crossing asteroids can account for the majority of Mars craters over an interval of several aeons, indicating that we see back in time no further than part-way into a period of intense bombardment. An early period of erosion and deposition is thus suggested. Section V presents a comparison with results and terminology of other authors.

  7. 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.

  8. SNC meteorites - Clues to Martian petrologic evolution?

    NASA Astrophysics Data System (ADS)

    McSween, H. Y.

    1985-11-01

    Shergottites, nakhlites and the Chassigny meteorites (SNC group) may have originated on Mars. The shergottites are medium-grained basalts, the nakhlites are pyroxenites and the Chassigny is a dunite. The SNC group is petrologically diverse but differs from all other known achondrites in terms of mineral chemistry, the redox state, the oxygen isotopic composition and the radiometric ages. The SNC stones are mafic and ultramafic cumulate rocks with mineralogies that indicate rapid cooling and crystallization from tholeiitic magmas which contained water and experienced a high degree of oxidation. The characteristics suggest formation from a large parent body, i.e., a planet, but not earth. The estimated ages for the rocks match the estimated ages for several mapped Martian volcanoes in the Tharsis region. Additionally, the elemental and isotopic abundances of atmospheric gases embedded in melts in the SNC stones match Viking Lander data for the Martian atmosphere. However, reasons are cited for discounting the possibility that a large meteorite(s) collided with Mars about 180 myr ago and served as the mechanism for ejecting the SNC stones to earth.

  9. 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.

  10. Minor constituents in the Martian atmosphere from the ISM/Phobos experiment.

    PubMed

    Rosenqvist, J; Drossart, P; Combes, M; Encrenaz, T; Lellouch, E; Bibring, J P; Erard, S; Langevin, Y; Chassefiere, E

    1992-08-01

    Global Martian atmospheric results derived from the infrared imaging spectrometer ISM flown aboard the Phobos 2 Soviet spacecraft are presented. Over low altitude regions the expected CO mixing ratio of (8 +/- 3) x 10(-4) is measured. Variations of the 2.35-micrometers feature are inconsistent with this value over the Great Martian Volcanoes. If the 2.35-micrometers band is entirely attributable to carbon monoxide, the CO mixing ratio is typically depleted by a factor of 3 over these high altitude areas. Orography should play a major role in the existence of this CO "hole." If, however, these spectral variations at 2.35 micrometers are due to the surface composition, the fraction of the surface covered by the responsible mineral must smoothly decrease as the surface elevation decreases. This phenomenon implies a strong interaction between the surface and the atmosphere for the Great Martian Volcanoes. Diurnal behavior and latitudinal variations of water vapor are globally consistent with Viking measurements. During the Phobos observations, the water vapor amounts over the bright equatorial regions range around 11 pr-micrometers during the day. These amounts are slightly larger than those inferred from 1976 to 1979. The lack of global dust storms during 1988-1989 could explain the enhancement of H2O in the atmosphere. PMID:11539361

  11. The engineering of a nuclear thermal landing and ascent vehicle utilizing indigenous Martian propellant

    NASA Technical Reports Server (NTRS)

    Zubrin, Robert M.

    1991-01-01

    The following paper reports on a design study of a novel space transportation concept known as a 'NIMF' (Nuclear rocket using Indigenous Martian Fuel). The NIMF is a ballistic vehicle which obtains its propellant out of the Martian air by compression and liquefaction of atmospheric CO2. This propellant is subsequently used to generate rocket thrust at a specific impulse of 264 s by being heated to high temperature (2800 K) gas in the NIMFs' nuclear thermal rocket engines. The vehicle is designed to provide surface to orbit and surface to surface transportation, as well as housing, for a crew of three astronauts. It is capable of refueling itself for a flight to its maximum orbit in less than 50 days. The ballistic NIMF has a mass of 44.7 tonnes and, with the assumed 2800 K propellant temperature, is capable of attaining highly energetic (250 km by 34,000 km elliptical) orbits. This allows it to rendezvous with interplanetary transfer vehicles which are only very loosely bound into orbit around Mars. If a propellant temperature of 2000 K is assumed, then low Mars orbit can be attained; while if 3100 K is assumed, then the ballistic NIMF is capable of injecting itself onto a minimum energy transfer orbit to Earth in a direct ascent from the Martian surface.

  12. Martian atmospheric gravity waves simulated by a high-resolution general circulation model

    NASA Astrophysics Data System (ADS)

    Kuroda, Takeshi; Yiǧit, Erdal; Medvedev, Alexander S.; Hartogh, Paul

    2016-07-01

    Gravity waves (GWs) significantly affect temperature and wind fields in the Martian middle and upper atmosphere. They are also one of the observational targets of the MAVEN mission. We report on the first simulations with a high-resolution general circulation model (GCM) and present a global distributions of small-scale GWs in the Martian atmosphere. The simulated GW-induced temperature variances are in a good agreement with available radio occultation data in the lower atmosphere between 10 and 30 km. For the northern winter solstice, the model reveals a latitudinal asymmetry with stronger wave generation in the winter hemisphere and two distinctive sources of GWs: mountainous regions and the meandering winter polar jet. Orographic GWs are filtered upon propagating upward, and the mesosphere is primarily dominated by harmonics with faster horizontal phase velocities. Wave fluxes are directed mainly against the local wind. GW dissipation in the upper mesosphere generates a body force per unit mass of tens of m s^{-1} per Martian solar day (sol^{-1}), which tends to close the simulated jets. The results represent a realistic surrogate for missing observations, which can be used for constraining GW parameterizations and validating GCMs.

  13. Prototype detector development for measurement of high altitude Martian dust using a future orbiter platform

    NASA Astrophysics Data System (ADS)

    Pabari, Jayesh; Patel, Darshil; Chokhawala, Vimmi; Bogavelly, Anvesh

    2016-07-01

    Dust devils mostly occur during the mid of Southern hemisphere summer on Mars and play a key role in the background dust opacity. Due to continuous bombardment of micrometeorites, secondary ejecta come out from the Moons of the Mars and can easily escape. This phenomenon can contribute dust around the Moons and therefore, also around the Mars. Similar to the Moons of the Earth, the surfaces of the Martian Moons get charged and cause the dust levitation to occur, adding to the possible dust source. Also, interplanetary dust particles may be able to reach the Mars and contribute further. It is hypothesized that the high altitude Martian dust could be in the form of a ring or tori around the Mars. However, no such rings have been detected to the present day. Typically, width and height of the dust torus is ~5 Mars radii wide (~16950 km) in both the planes as reported in the literature. 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, a langmuir probe cannot explain the source of such dust particles. It is a puzzling question to the space scientist how dust has reached to such high altitudes. A dedicated dust instrument on future Mars orbiter may be helpful to address such issues. To study origin, abundance, distribution and seasonal variation of Martian dust, a Mars Orbit Dust Experiment (MODEX) is proposed. In order to measure the Martian dust from a future orbiter, design of a prototype of an impact ionization dust detector has been initiated at PRL. This paper presents developmental aspects of the prototype dust detector and initial results. The further work is underway.

  14. An ultraviolet simulator for the incident Martian surface radiation and its applications

    NASA Astrophysics Data System (ADS)

    Kolb, C.; Abart, R.; Bérces, A.; Garry, J. R. C.; Hansen, A. A.; Hohenau, W.; Kargl, G.; Lammer, H.; Patel, M. R.; Rettberg, P.; Stan-Lotter, H.

    2005-10-01

    Ultraviolet (UV) radiation can act on putative organic/biological matter at the Martian surface in several ways. Only absorbed, but not transmitted or reflected, radiation energy can be photo-chemically effective. The most important biological UV effects are due to photochemical reactions in nucleic acids, DNA or RNA, which constitute the genetic material of all cellular organisms and viruses. Protein or lipid effects generally play a minor role, but they are also relevant in some cases. UV radiation can induce wavelengths-specific types of DNA damage. At the same time it can also induce the photo-reversion reaction of a UV induced DNA photoproduct of nucleic acid bases, the pyrimidine dimers. Intense UVB and UVC radiation, experienced on early Earth and present-day Mars, has been revealed to be harmful to all organisms, including extremophile bacteria and spores. Moreover, the formation of oxidants, catalytically produced in the Martian environment through UV irradiation, may be responsible for the destruction of organic matter on Mars. Following this, more laboratory simulations are vital in order to investigate and understand UV effects on organic matter in the case of Mars. We have designed a radiation apparatus that simulates the anticipated Martian UV surface spectrum between 200 and 400 nm (UVC UVA). The system comprises a UV enhanced xenon arc lamp, special filter-sets and mirrors to simulate the effects of the Martian atmospheric column and dust loading. We describe the technical setup and performance of the system and discuss its uses for different applications. The design is focused on portability, therefore, the Mars-UV simulator represents a device for several different Mars simulation facilities with specific emphasis on Mars research topics.

  15. Effects of a Simulated Martian UV Flux on the Cyanobacterium, Chroococcidiopsis sp. 029

    NASA Astrophysics Data System (ADS)

    Cockell, Charles S.; Schuerger, Andrew C.; Billi, Daniela; Imre Friedmann, E.; Panitz, Corinna

    2005-06-01

    Dried monolayers of Chroococcidiopsis sp. 029, a desiccation-tolerant, endolithic cyanobacterium, were exposed to a simulated martian-surface UV and visible light flux, which may also approximate to the worst-case scenario for the Archean Earth. After 5 min, there was a 99% loss of cell viability, and there were no survivors after 30 min. However, this survival was approximately 10 times higher than that previously reported for Bacillus subtilis. We show that under 1 mm of rock, Chroococcidiopsis sp. could survive (and potentially grow) under the high martian UV flux if water and nutrient requirements for growth were met. In isolated cells, phycobilisomes and esterases remained intact hours after viability was lost. Esterase activity was reduced by 99% after a 1-h exposure, while 99% loss of autofluorescence required a 4-h exposure. However, cell morphology was not changed, and DNA was still detectable by 4',6-diamidino-2-phenylindole staining after an 8-h exposure (equivalent to approximately 1 day on Mars at the equator). Under 1 mm of simulant martian soil or gneiss, the effect of UV radiation could not be detected on esterase activity or autofluorescence after 4 h. These results show that under the intense martian UV flux the morphological signatures of life can persist even after viability, enzymatic activity, and pigmentation have been destroyed. Finally, the global dispersal of viable, isolated cells of even this desiccation-tolerant, ionizing-radiation-resistant microorganism on Mars is unlikely as they are killed quickly by unattenuated UV radiation when in a desiccated state. These findings have implications for the survival of diverse microbial contaminants dispersed during the course of human exploratory class missions on the surface of Mars.

  16. Highly Siderophile Element Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Neal, C. R.; Ely, J. C.

    2001-01-01

    Critical evaluation of new and literature data for highly siderophile elements (HSE) in Martian (SNC) meteorites allows several first order conclusions to be drawn. (i) Re concentrations in SNC meteorites are nearly constant (within a factor of two) and do not correlate with rock type. Exceptions to this rule are Chassigny and Dar al Gani (DaG) 476, both of which are inferred to have experienced terrestrial Re contamination. (ii) Fractionations between Rh and Pd are small. Excluding Shergotty, the Rh/Pd ratio of the SNC suite is 0.22\\pm0.05. (iii) Os and Ir contents vary by about four orders of magnitude; and positive correlations with MgO, Cr, and Ni suggest that these variations are not controlled by sulfide fractionation. A possible exception is the orthopyroxenite ALH84001, whose HSE's (including Ni, which is compatible in opx) are very low. (iv) Zagami, Shergotty, and Nakhla have nearly identical HSE signatures. Shergotty and Zagami have experienced assimilation-fractional crystallization (AFC) and have "crustal" Sr and Nd isotopic signatures. Conversely, the Nakhla parent was a small degree partial melt of a depleted mantle that interacted little with the Martian crust. These observations suggest that "evolved" HSE signatures can be produced by either fractional crystallization or small degrees of partial melting. (v) Chassigny and other mafic SNC's have HSE signatures that are very distinct from those of Nakhla-Zagami-Shergotty. The HSE elemental ratios of mafic SNC's approach chondritic, implying that the Martian mantle has nearly chondritic relative abundances of the HSE's. (vi) This chondritic HSE signature is observed in SNC's of various ages, suggesting that this is an ancient feature that has not evolved over time. (vii) No correlation is observed between HSE's and signatures of crustal contamination (e.g., Sr isotopes), indicating that the HSE signatures of the SNC suite are not derived from the crust. (vii) The Ru/Pd for the SNC suite ratio is about

  17. 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

  18. Mapping and analysis of Martian landslides

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni B.; Frattini, Paolo; Valbuzzi, Elena; Russo, Valeria

    2013-04-01

    This work is part of a larger effort aimed to a more quantitative description of landslide phenomena on Mars and the understanding of rock mass properties and landslide mobility with respect to their Earth equivalents. Recently, large satellite imagery datasets have become available and they have been mosaicked in different suitable tools making mapping an easier job than before. Furthermore, the availability of other georeferenced database makes possible and easily feasible some spatially distributed analyses. We prepared a new landslide inventory to acquire information about: landslide size distribution and areal density, controls of geometrical condition along Martian slopes, landslide typology and mechanism, relationship with impact craters distribution, runout, volume estimates, characteristic features. We adopted Google Earth, Google, Inc. as a mapping tool using both visible and CTX images. Landslides have been mapped according to standard geomorphological criteria, by two landslide experts delineating both the landslide scar and accumulation limits, associating each scarp to a deposit. Multiple accumulations have been differentiated where possible to obtain a more sound dataset. We prevalently mapped landslides located along the Martian valleys and Chasma flanks with only minor attention to classical block and slump instabilities typical of crater rim failures. This because we were mainly interested in long runout landslides or complex failures which could allow to define some rock mass characteristics along these slopes, and to study landslide mobility with respect to Earth equivalent phenomena. So long runout landslides have been mapped also when recognized within crater rims. Topographic characteristics have been extracted by means of the available MOLA dataset. The inventory presently consists of 1232 landslides covering a total area of about 180,000 km2. Landslide size ranges from 0.15 km2 to a maximum of 12,000 km2. We examined area

  19. Detailed Cloud Patterns in Martian Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Cold and cloudy mornings; cool, hazy afternoons. High winds aloft and weather fronts moving slowly to the east. It is winter in the Martian northern hemisphere. One of the many reasons to study Mars is that, at times, its weather is very 'Earth-like.' At this time of the Martian year, clouds are abundant, especially in the morning and especially in the high northern latitudes. Clouds and fogs are also observed in low-lying areas farther to the south, in some lowlands they are as far south as the equator.

    The above color composite images, obtained by Mars Global Surveyor's camera on June 4, 1998, illustrate this Martian 'weather report.' Most of the thick, white clouds seen here occur north of latitude 35oN (roughly equivalent to Albuquerque NM, Memphis TN, and Charlotte, NC). Fog (seen as bright orange because it is lighter than the ground but some of the ground is still visible) occupies the lowest portions of the Kasei Valles outflow channel around 30oN and at 25oN.

    Several different types of cloud features are seen. The repetitious, wash-board pattern of parallel lines are 'gravity wave clouds'. These commonly form, in the lee--downwind side-- of topographic features such as mountain ranges (on Earth) or crater rims (on Mars), under very specific atmospheric conditions (low temperatures, high humidity, and high wind speeds). In this area, the wave clouds are lower in the atmosphere than some of the other clouds. These other clouds show attributes reflecting more the regional weather pattern, occasionally showing the characteristic 'slash' shape (southwest to northeast) of a weather front. These clouds probably contain mostly crystals of water ice but, depending on the temperature at high altitude (and more likely closer to the pole), some could also contain frozen carbon dioxide ('dry ice').

    MOC images 34501 (the red wide angle image) and 34502 (the blue wide angle image) were obtained on Mars Global Surveyor's 345th orbit about the planet

  20. 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.

  1. 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.

  2. 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.

  3. Prototype Backscatter Moessbauer Spectrometer for Measurement of Martian Surface Mineralogy

    NASA Technical Reports Server (NTRS)

    Shelfer, T. D.; Morris, R. V.; Agresti, D. G.; Nguyen, T.; Wills, E. L.; Shen, M. H.

    1993-01-01

    We have designed and successfully tested a prototype of a backscatter Moessbauer spectrometer (BaMS) targeted for use on the Martian surface to (1) determine oxidation states of iron, and (2) identify and determine relative abundances of iron-bearing mineralogies. No sample preparation is required to perform measurements; it is only necessary to bring sample and instrument into physical contact. The prototype meets our projected specification for a flight instrument in terms of mass, power, and volume. A Moessbauer spectrometer on the Martian surface would provide wide variety of information about the current state of the Martian surface, and this information is described.

  4. 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.

  5. Luminescence Dating of Martian Polar Deposits: Concepts and Preliminary Measurements Using Martian Soil Analogs

    NASA Astrophysics Data System (ADS)

    Lepper, K.; Kuhns, C. K.; McKeever, S. W. S.; Sears, D. W. G.

    2000-08-01

    Martian polar deposits have the potential to reveal a wealth of information about the evolution of Mars' climate and surface environment. However, as pointed out by Clifford et al. in the summary of the First International Conference on Mars Polar Science and Exploration, 'The single greatest obstacle to unlocking and interpreting the geologic and climatic record preserved at the [martian] poles is the need for absolute dating.' At that same conference Lepper and McKeever proposed development of luminescence dating as a remote in-situ technique for absolute dating of silicate mineral grains incorporated in polar deposits. Clifford et al. have also acknowledged that luminescence dating is more practical from cost, engineering, and logistical perspectives than other isotope-based methods proposed for in-situ dating on Mars. We report here the results of ongoing experiments with terrestrial analogs of martian surface materials to establish a broad fundamental knowledge base from which robust dating procedures for robotic missions may be developed. This broad knowledge base will also be critical in determining the engineering requirements of remote in-situ luminescence dating equipment intended for use on Mars. Additional information can be found in the original extended abstract.

  6. A search for the effects exerted by a possible Martian intrinsic magnetic field on its SEP environment

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, Susan; Alho, Markku; Kallio, Esa; Jarvinen, Riku; Dyadechkin, Sergey; Wedlund, Cyril Simon

    2014-05-01

    Present-day Mars does not have a significant global intrinsic magnetic field although it displays surface magnetic anomalies. In the past 'young Mars' may have had a strong intrinsic magnetic field. Induced Martian magnetic fields affect the properties of Solar Energetic Particles, (SEPs), near the planet. Recent Martian SEP environment studies, made using self-consistent global plasma simulations [McKenna-Lawlor et al. 2012; Kallio et al., 2012], have shown that piled up magnetic fields in the Martian magnetosheath/magnetosphere affect the behaviour of SEPs, resulting, for instance, in dramatic magnetic shadowing. In these studies when correlating the simulations with in situ measurements made by the SLED instrument aboard the Phobos spacecraft, Mars was not assumed to have an intrinsic magnetic field, which raises the question as to whether, and how, a residual Martian intrinsic magnetic field may have contributed to affecting the disturbed solar energetic particles (SEPs) recorded near the planet. In the present work we have extended our hybrid modelling of SEPs by assuming that Mars has an intrinsic magnetic field. Then, we compare a non-magnetized Mars with a magnetized Mars in terms of SEP measurements. We also discuss the consequences of the results, keeping in mind the forthcoming in situ SEP instrument measurements which are scheduled to start near Mars at the end of 2014 on-board the MAVEN spacecraft.

  7. The observed day-to-day variability of Mars water vapor

    NASA Technical Reports Server (NTRS)

    Jakosky, Bruce M.; Lapointe, Michael R.; Zurek, Richard W.

    1987-01-01

    The diurnal variability of atmospheric water vapor as derived from the Viking MAWD data is discussed. The detection of day to day variability of atmospheric water would be a significant finding since it would place constraints on the nature of surface reservoirs. Unfortunately, the diurnal variability seen by the MAWD experiment is well correlated with the occurrence of dust and/or ice hazes, making it difficult to separate real variations from observational effects. Analysis of the day to day variability of water vapor in the Martian atmosphere suggests that the observations are, at certain locations and seasons, significantly affected by the presence of water-ice hazes. Because such effects are generally limited to specific locations, such as Tharsis, Lunae Planum, and the polar cap edge during the spring, the seasonal and latitudinal trends in water vapor that have been previously reported are not significantly affected.

  8. 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.

  9. Microscopic Comparison of Airfall Dust to Martian Soil

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This pair of images taken by the Optical Microscope on NASA's Phoenix Mars Lander offers a side-by-side comparison of an airfall dust sample collected on a substrate exposed during landing (left) and a soil sample scooped up from the surface of the ground beside the lander. In both cases the sample is collected on a silicone substrate, which provides a sticky surface holding sample particles for observation by the microscope.

    Similar fine particles at the resolution limit of the microscope are seen in both samples, indicating that the soil has formed from settling of dust.

    The microscope took the image on the left during Phoenix's Sol 9 (June 3, 2008), or the ninth Martian day after landing. It took the image on the right during Sol 17 (June 11, 2008).

    The scale bar is 1 millimeter (0.04 inch).

    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.

  10. Temperature measurements of a Martian local dust storm

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph

    1995-01-01

    A technique for estimating the ground and near-ground atmospheric temperatures within a Martian local dust storm is presented. It is applied to soundings taken by the Viking orbiter infrared thermal mapper (IRTM) instrument at four times-of-day for one storm. Essentially, a comparison is made between infrared radiances emerging from the storm interior and those from the region surrounding the storm. Particle extinction properties are assumed to be independent of position in the storm region, and scattering properties must be selected arbitrarily. For the storm studied here, the ground temperature in the interior is at least 6 K cooler, whereas the near-ground atmospheric temperature may be less than or comparable to, those of the surroundings. The thermal structure of the storm interior did not change measurably between 11.5 and 16.6 hours local time. These observations favor the theories of dust storm development in which regional winds rather than local, dust driven convection initiate the mobilization of dust from the surface. It also concluded that the optical properties of dust particles in this local storm differ from those observed by Mariner 9 during the 1971-1972 global dust storm.

  11. Temperature measurements of a Martian local dust storm

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph

    1995-01-01

    A technique for estimating the ground and near-ground atmospheric temperatures within a Martian local dust storm is presented. It is applied to soundings taken by the Viking orbiter infrared thermal mapper (IRTM) instrument at four times-of-day for one storm. Essentially, a comparison is made between infrared radiances emerging from the storm interior and those from the region surrounding the storm. Particle extinction properties are assumed to be independent of position in the storm region, and scattering properties must be selected arbitrarily. For the storm studied here, the ground temperature in the interior is at least 6 K cooler, whereas the near-ground atmospheric temperature may be less than or comparable to, those of the surroundings. The thermal structure of the storm interior did not change measurably between 11.5 and 16.6 hours local time. These observations favor theories of dust storm development in which regional winds rather than local, dust-driven convection initiate the mobilization of dust from the surface. It is also concluded that the optical properties of dust particles in this local storm differ from those observed by Mariner 9 during the 1971-1972 global dust storm.

  12. Transient Density Enhancements of the Martian Orbiting Dust Torus

    NASA Astrophysics Data System (ADS)

    Juhasz, A.; Horanyi, M.

    2014-12-01

    The moons Phobos and Deimos have been suggested to be responsible for sustaining a permanently present dust cloud around Mars. The equilibrium size and spatial distribution of this dust torus has been the subject of numerous theoretical studies. However, no observational evidence has been found as of yet. Because of the renewed interest in Phobos and Deimos as potential targets for human precursor mission to Mars, there is a new opportunity for the detection of the putative Martian dust clouds using in situ measurements. Both Phobos and Deimos, as all airless bodies in the solar system, are continually bombarded by interplanetary dust grains, generating secondary ejecta particles. The surface gravity escape of these objects are low, hence most secondary particles escapethem, but remain in orbit about Mars. Subsequent perturbations by solar radiation pressure, electromagnetic forces acting on charged grains, and collisions with the moons or Mars itself limit the lifetime of the produced particles. The size dependent production rates and lifetimes set the most abundant particle size range of 10 - 30 micron in radius. Large, but short-lived, dust density enhancements can be predicted during periods of meteor showers. Also, comet Siding Spring will flyby Mars in October, 2014. Its dust tail can 'sand-blast' both Phobos and Deimos, dramatically increasing their dust production for a few hours. We present the results of our numerical studies on the temporal and spatial evolution of the dust clouds raised during highly enhanced production rates that last only hours-to-days.

  13. Martian Surface Mineralogy from Rovers with Spirit, Opportunity, and Curiosity

    NASA Technical Reports Server (NTRS)

    Morris, Richard V.

    2016-01-01

    Beginning in 2004, NASA has landed three well-instrumented rovers on the equatorial martian surface. The Spirit rover landed in Gusev crater in early January, 2004, and the Opportunity rover landed on the opposite side of Mars at Meridian Planum 21 days later. The Curiosity rover landed in Gale crater to the west of Gusev crater in August, 2012. Both Opportunity and Curiosity are currently operational. The twin rovers Spirit and Opportunity carried Mossbauer spectrometers to determine the oxidation state of iron and its mineralogical composition. The Curiosity rover has an X-ray diffraction instrument for identification and quantification of crystalline materials including clay minerals. Instrument suites on all three rovers are capable of distinguishing primary rock-forming minerals like olivine, pyroxene and magnetite and products of aqueous alteration in including amorphous iron oxides, hematite, goethite, sulfates, and clay minerals. The oxidation state of iron ranges from that typical for unweathered rocks and soils to nearly completely oxidized (weathered) rocks and soils as products of aqueous and acid-sulfate alteration. The in situ rover mineralogy also serves as ground-truth for orbital observations, and orbital mineralogical inferences are used for evaluating and planning rover exploration.

  14. Stratigraphy of the Martian northern plains

    NASA Technical Reports Server (NTRS)

    Tanaka, K. L.

    1993-01-01

    The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

  15. 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

  16. Dynamics of a terraformed Martian biosphere

    NASA Astrophysics Data System (ADS)

    Fogg, Martyn J.

    1993-08-01

    The outcome of terraforming on Mars is examined by considering the function of its biosphere. By borrowing a life-support model of the Earth's biosphere, scenarios of ecopoiesis and full terraforming are contrasted in terms of their energy flow and matter cycling. It is argued that Martian colonists are unlikely to be satisfied with the services provided by the anaerobic biosphere produced by ecopoiesis and that full terraforming will be the specific goal of planetary engineering. The distance of Mars from the sun and its probable lack of a closed rock cycle will require small scale, conscious intervention in biogeochemical cycles to maintain the habitability of the planet. Vernadsky's concept of the noosphere (an envelope of mind) will thus have more relevance to Mars as an abode of life than Lovelock's Gaia hypothesis.

  17. 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

  18. 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.

  19. Mottled terrain - A continuing Martian enigma

    NASA Technical Reports Server (NTRS)

    Scott, D. H.; Underwood, J. R., Jr.

    1991-01-01

    The mottled plains material found in the northern Martian lowlands is discussed in terms of Mariner and Viking images as well as geologic mapping based on Viking images. The mottling in Mariner 9 images of this area was associated with albedo contrasts between bright crater-ejecta blankets and dark intercrater material, and dark-crested knobs. The interpretation of the plains material based on the Mariner images is compared to an interpretation of the higher-quality Viking images. Based on the newer images, the mottled terrain is theorized to be comprised of the four constituent members of the Vastitas Borealis formation of Late Hesperian age. Fluvial, aeolian, and glaciotectonic processes are responsible for the extensive modifications of the apparently volcanic formations. The northern plains are not completely understood in spite of the Viking images, and the varied geology in those plains requires more sampling to confirm the theories.

  20. 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.

  1. Martian dust devils detector over FPGA

    NASA Astrophysics Data System (ADS)

    de Lucas, E.; Miguel, M. J.; Mozos, D.; Vázquez, L.

    2012-04-01

    Digital applications that must be on-board space missions must comply with a very restrictive set of requirements. These include energy efficiency, small volume and weight, robustness and high performance. Moreover, these circuits cannot be repaired in case of error, so they must be reliable or provide some way to recover from errors. These features make reconfigurable hardware (FPGAs, Field Programmable Gate Arrays) a very suitable technology to be used in space missions. This paper presents a Martian dust devil detector implemented on an FPGA. The results show that a hardware implementation of the algorithm presents very good numbers in terms of performance compared with the software version. Moreover, as the amount of time needed to perform all the computations on the reconfigurable hardware is small, this hardware can be used most of the time to realize other applications.

  2. Martian dust devils detector over FPGA

    NASA Astrophysics Data System (ADS)

    de Lucas, E.; Miguel, M. J.; Mozos, D.; Vázquez, L.

    2011-12-01

    Digital applications that must be on-board of space missions must accomplish a very restrictive set of requirements. These include energy efficiency, small volume and weight, robustness and high performance. Moreover these circuits can not be repaired in case of error, so they must be reliable or provide some way to recover from errors. These features make reconfigurable hardware (FPGAs, Field Programmable Gate Arrays) a very suitable technology to be used in space missions. This paper presents a Martian dust devil detector implemented on a FPGA. The results show that a hardware implementation of the algorithm present very good numbers in terms of performance compared with the software version. Moreover, as the amount of time needed to perform all the computations on the reconfigurable hardware is small, this hardware can be used more of the time to realize other applications.

  3. Early Dust Storm Season Thermal State of the Martian Atmosphere - Latest Results from the Horizon Science Experiment

    NASA Astrophysics Data System (ADS)

    Martin, T. Z.; Murphy, J. R.

    1999-09-01

    The Horizon Science Experiment (HORSE) uses the Mars Horizon Sensor Assembly on the MGS orbiter to measure 15 micrometer band thermal emission from the middle Martian atmosphere. Since mapping began in March 1999, data acquisition has been continuous, with 12 orbits/day providing rapid longitudinal coverage. The instrument's four quadrants aligned orthogonally on the Martian limb provide important coverage in local time; two quadrants fore and aft give redundant sampling of the ground track, while the other two sample +/- 1.4 hrs in local time at the equator. Equator crossing is nominally at 3 AM and 3 PM. This coverage of six local times per day for most of the planet means that the MHSA is well suited to detect diurnal temperature variations, including the semidiurnal tidal mode, which is particularly sensitive to the presence of atmospheric dust. We report recent results on the global thermal state; specific dust events; diurnal behavior; and other wavelike phenomena.

  4. Organic degradation under simulated Martian conditions

    NASA Astrophysics Data System (ADS)

    Stoker, Carol R.; Bullock, Mark A.

    1997-05-01

    We report on laboratory experiments which simulate the breakdown of organic compounds under Martian surface conditions. Chambers containing Mars-analog soil mixed with the amino acid glycine were evacuated and filled to 100 mbar pressure with a Martian atmosphere gas mixture and then irradiated with a broad spectrum Xe lamp. Headspace gases were periodically withdrawn and analyzed via gas chromatography for the presence of organic gases expected to be decomposition products of the glycine. The quantum efficiency for the decomposition of glycine by light at wavelengths from 2000 to 2400 Å was measured to be 1.46+/-1.0×10-6molecules/photon. Scaled to Mars, this represents an organic destruction rate of 2.24+/-1.2×10-4g of Cm-2yr-1. We compare this degradation rate with the rate that organic compounds are brought to Mars as a result of meteoritic infall to show that organic compounds are destroyed on Mars at rates far exceeding the rate that they are deposited by meteorites. Thus the fact that no organic compounds were found on Mars by the Viking Lander Gas Chromatograph Mass Spectrometer experiment can be explained without invoking the presence of strong oxidants in the surface soils. The organic destruction rate may be considered as an upper bound for the globally averaged biomass production rate of extant organisms at the surface of Mars. This upper bound is comparable to the slow growing cryptoendolithic microbial communities found in dry Antarctica deserts. Finally, comparing these organic destruction rates to recently reported experiments on the stability of carbonate on the surface of Mars, we find that organic compounds may currently be more stable than calcite.

  5. 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.

  6. 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

  7. Analyzing Martian winds and tracer concentrations using Mars Observer data

    NASA Technical Reports Server (NTRS)

    Houben, Howard C.

    1993-01-01

    During the courses of a day, the Mars Observer spacecraft will acquire globally distributed profiles of the martian atmosphere. It is highly desirable that this data be assembled into synoptic weather maps (complete specifications of the atmospheric pressure, temperature, and winds at a given time), which can in turn be used as starting points in the study of many meteorological phenomena. Unfortunately, the special nature of the Mars Observer data presents several challenges above and beyond the usual difficult problem of data initialization. Mars Observer atmospheric data will consist almost exclusively of asynoptic vertical profiles of temperatures (or radiances) and pressures, whereas winds are generally in balance with horizontal gradients of these quantities (which will not be observed). It will therefore be necessary to resort to dynamical models to analyze the wind fields. As a rule, data assimilation into atmospheric models can result in the generation of spurious gravity waves, so special steps must be taken to suppress these. In addition, the asynoptic nature of the data will require a four-dimensional (space and time) data assimilation scheme. The problem is to find a full set of meteorological fields (winds and temperatures) such that, when marched forward in time in the model, they achieve a best fit (in the weighted least-squares sense) to the data. The proposed solution is to develop a model especially for the Mars Observer data assimilation problem. Gravity waves are filtered from the model by eliminating all divergence terms from the prognostic divergence equation. This leaves a diagnostic gradient wind relation between the rotational wind and the temperature field. The divergent wind is diagnosed as the wind required to maintain the gradient wind balance in the presence of the diabatic heating. The primitive equations of atmospheric dynamics (with three principal dependent variables) are thus reduced to a simpler system with a single prognostic

  8. Possible Meteorites in the Martian Hills (False Color)

    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 false-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 750 nanometers, 530 nanometers, and 430 nanometers. The image is presented in false color to emphasize differences among

  9. Numerical simulations of the formation and evolution of water ice clouds in the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Michelangeli, Diane V.; Toon, Owen B.; Haberle, Robert M.; Pollack, James B.

    1993-01-01

    A model of the formation, evolution, and description of Martian water ice clouds is developed which well reproduces the physical processes governing the microphysics of water ice cloud formation on Mars. The model is used to show that the cloud properties are most sensitive to the temperature profile, the number of days for which condensation previously occurred, the contact angle, and the presence of incoming meteoritic debris at the top of the atmosphere. The AM-PM differences in optical depths measured at the Viking Lander site were successfully simulated with the model, obtaining total column optical depths of ice of a few tenths in agreement with observations.

  10. Recent Movements: New Landslides in Less than 1 Martian Year

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Changes between 1 February 1998 and 18 November 1999

    Crater at 6oS, 184oW on 01 FEB 1998 [figure removed for brevity, see original site]

    3-D Anaglyph View--PIA02380 [figure removed for brevity, see original site]

    What is happening on Mars right now? Pictures that show changes occurring from time to time give some clues as to what processes are shaping the modern martian landscape. Dust devils, dust storms, and polar frosts are all known to cause change sin the surface every martian year. But what about other geologic processes? How 'active' is Mars today? The Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) has been in orbit long enough that it is starting to provide some answers. MGS began orbiting Mars in September 1997. Since that time, it has seen the planet cycle through more than 1 of its 687-Earth-days-long years. The pictures shown here document changes observed by the MOC caused by small landslides.

    The picture at the lower left (above) shows a shallow crater located near Apollinaris Patera at 6oS, 184oW, that was photographed by MOC in February 1998. The walls of this crater exhibit approximately 100 dark streaks running down its slopes. These streaks have formed as small landslides or avalanches and are probably composed of sand and/or silt. The image is illuminated by sunlight from the lower left, and the crater is about 5 kilometers (3 miles) across. The white box shows the location of a section of the crater that was photographed again in mid-November 1999, about 92% of a Martian Year later.

    The top picture shows a comparison of the southeastern crater wall as it appeared on February 1, 1998, and again on November 18, 1999. (Note that the picture has been rotated relative to the context image at lower left). During the time between the two images, three new dark slope streaks formed (arrows, top right). The older streaks are lighter and fainter than these new, dark ones, suggesting that streaks fade with time

  11. Origin and Reactivity of the Martian Soil: A 2003 Micromission

    NASA Technical Reports Server (NTRS)

    Yen, Albert S.; Kim, S. Sam; Marshall, John; Murray, Bruce C.

    1999-01-01

    The role of water in the development of the martian surface remains a fundamental scientific question. Did Mars have one or more "warm and wet" climatic episodes where liquid water was stable at the surface? If so, the mineral phases present in the soils should be consistent with a history of aqueous weathering. More generally, the formation of hydrated mineral phases on Mars is a strong indicator of past habitable surface environments. The primary purpose of this investigation is to help resolve the question of whether such aqueous indicators are present on Mars by probing the upper meter for diagnostic mineral species. According to Burns [1993], the formation of the ferric oxides responsible for the visible color of Mars are the result of dissolution of Fe (+2) phases from basalts followed by aqueous oxidation and precipitation of Fe" mineral assemblages. These precipitates likely included iron oxyhydroxides such as goethite (a-FeOOH) and lepidocrocite (g-FeOOH), but convincing evidence for these phases at the surface is still absent. The stability of these minerals is enhanced beneath the surface, and thus we propose a subsurface search for hydroxylated iron species as a test for a large-scale chemical weathering process based on interactions with liquid water. It is also possible that the ferric minerals on Mars are not aqueous alteration products of the rocks. A chemical study of the Pathfinder landing site concluded that the soils are not directly derived from the surrounding rocks and are enhanced in Mg and Fe. The additional source of these elements might be from other regions of Mars and transported by winds, or alternatively, from exogenic sources. Gibson [1970] proposed that the spectral reflectivity of Mars is consistent with oxidized meteoritic material. Yen and Murray [1998] further extend Gibson's idea and show, in the laboratory, that metallic iron can be readily oxidized to maghemite and hematite under present-day martian surface conditions (in the

  12. Origin and Reactivity of the Martian Soil: A 2003 Micromission

    NASA Astrophysics Data System (ADS)

    Yen, Albert S.; Kim, S. Sam; Marshall, John; Murray, Bruce C.

    1999-09-01

    The role of water in the development of the martian surface remains a fundamental scientific question. Did Mars have one or more "warm and wet" climatic episodes where liquid water was stable at the surface? If so, the mineral phases present in the soils should be consistent with a history of aqueous weathering. More generally, the formation of hydrated mineral phases on Mars is a strong indicator of past habitable surface environments. The primary purpose of this investigation is to help resolve the question of whether such aqueous indicators are present on Mars by probing the upper meter for diagnostic mineral species. According to Burns [1993], the formation of the ferric oxides responsible for the visible color of Mars are the result of dissolution of Fe (+2) phases from basalts followed by aqueous oxidation and precipitation of Fe" mineral assemblages. These precipitates likely included iron oxyhydroxides such as goethite (a-FeOOH) and lepidocrocite (g-FeOOH), but convincing evidence for these phases at the surface is still absent. The stability of these minerals is enhanced beneath the surface, and thus we propose a subsurface search for hydroxylated iron species as a test for a large-scale chemical weathering process based on interactions with liquid water. It is also possible that the ferric minerals on Mars are not aqueous alteration products of the rocks. A chemical study of the Pathfinder landing site concluded that the soils are not directly derived from the surrounding rocks and are enhanced in Mg and Fe. The additional source of these elements might be from other regions of Mars and transported by winds, or alternatively, from exogenic sources. Gibson [1970] proposed that the spectral reflectivity of Mars is consistent with oxidized meteoritic material. Yen and Murray [1998] further extend Gibson's idea and show, in the laboratory, that metallic iron can be readily oxidized to maghemite and hematite under present-day martian surface conditions (in the

  13. Variability of the thermospheric temperatures of Mars during 9 Martian Years as given by a ground-to-exosphere Global Climate Model

    NASA Astrophysics Data System (ADS)

    Gonzalez-Galindo, Francisco; Forget, Francois; Garcia-Comas, Maya; Millour, Ehouarn; Lopez-Valverde, Miguel; Montabone, Luca

    2016-07-01

    The temperature of the Martian upper thermosphere is one of the main factors affecting the rate of the different escape to space processes which shape the Martian atmosphere and its long-term evolution. A good knowledge of the variability of this parameter is thus very important in order to gain a deeper understanding of the present-day escape rate and of the evolutive history of Mars. We have used a ground-to-exosphere Global Climate Model, the LMD-MGCM, to simulate the variability of the temperatures at the Martian exobase during the last 9 Martian Years (MY24-MY32, approximately 17 terrestrial years). The simulations include for the first time a realistic day-to-day variability of the UV solar flux. The simulated temperatures are in good agreement with the exospheric temperatures derived from Precise Orbit Determination of Mars Global Surveyor. A significant inter-annual variability of the temperatures, due to both the 11 year solar cycle and the variability of the dust load in the lower atmosphere, is predicted by the model. The variation in the solar output produced by the 27 day solar rotation cycle is seen in the simulated exobase temperatures. We also find that the global dust storms in MY25 and MY28 significantly impact the temperatures at the exobase. These results underline the importance of properly taking into account the dust and solar variabilities to simulate the upper atmosphere of Mars.

  14. 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

  15. 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.

  16. Estimating Volume of Martian Valleys Using Axelsson Algorithm

    NASA Astrophysics Data System (ADS)

    Jung, J. H.; Kim, C. J.; Heo, J.; Luo, W.

    2012-03-01

    A progressive TIN densification algorithm is adapted to estimate the volume martian valley networks (VN) based MOLA point data. This method can be used to estimate the global water inventory associated with VN.

  17. 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.

  18. '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.

  19. Halobacterium Salinarum: Polyextremophile Model for Life Inside Martian Halite

    NASA Astrophysics Data System (ADS)

    Srivastava, A.

    2014-07-01

    The present work briefly reviews the recent studies on long-term survival potential of Halobacterium salinarum in ancient terrestrial halite and studies the possible survival ability of this poly-extremophilic archaeon inside martian halite.

  20. Martian stable isotopes: volatile evolution, climate change and exobiological implications

    NASA Technical Reports Server (NTRS)

    Jakosky, B. M.

    1999-01-01

    Measurements of the ratios of stable isotopes in the martian atmosphere and crust provide fundamental information about the evolution of the martian volatile and climate system. Current best estimates of the isotope ratios indicate that there has been substantial loss of gases to space and exchange of gases between the atmosphere and the crust throughout geologic time; exchange may have occurred through circulation of water in hydrothermal systems. Processes of volatile evolution and exchange will fractionate the isotopes in a manner that complicates the possible interpretation of isotopic data in terms of any fractionation that may have been caused by martian biota, and must be understood first. Key measurements are suggested that will enhance our understanding of the non-biological fractionation of the isotopes and of the evolution of the martian volatile system.

  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. Hematite Mineralized Bacterial Remnants: Implications for Martian Hematite Deposits

    NASA Technical Reports Server (NTRS)

    Schelble, Rachel T.; Westall, Frances; Allen, Carlton C.; Brearley, Adrian J.

    2001-01-01

    Hematite mineralized bacterial remnants in the Gunflint Formation [early Proterozoic] can be used as an analog for potential microfossils in martian iron deposits. Additional information is contained in the original extended abstract.

  3. Identifying Martian Hydrothermal Sites: Geological Investigation Utilizing Multiple Datasets

    NASA Technical Reports Server (NTRS)

    Dohm, J. M.; Baker, V. R.; Anderson, R. C.; Scott, D. H.; Rice, J. W., Jr.; Hare, T. M.

    2000-01-01

    Comprehensive geological investigations of martian landscapes that may have been modified by magmatic-driven hydrothermal activity, utilizing multiple datasets, will yield prime target sites for future hydrological, mineralogical, and biological investigations.

  4. 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

  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. 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.

  7. Dust Ejection Induced by Small Meteoroids Impacting Martian Surface

    NASA Technical Reports Server (NTRS)

    Shuvalov, Valery

    2001-01-01

    The objective of this study is numerical modeling of meteoroid impact on the martian surface and determination of the resulting dust cloud parameters. Additional information is contained in the original extended abstract.

  8. 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.

  9. Standardizing the nomenclature of Martian impact crater ejecta morphologies

    USGS Publications Warehouse

    Barlow, Nadine G.; Boyce, Joseph M.; Costard, Francois M.; Craddock, Robert A.; Garvin, James B.; Sakimoto, Susan E.H.; Kuzmin, Ruslan O.; Roddy, David J.; Soderblom, Laurence A.

    2000-01-01

    The Mars Crater Morphology Consortium recommends the use of a standardized nomenclature system when discussing Martian impact crater ejecta morphologies. The system utilizes nongenetic descriptors to identify the various ejecta morphologies seen on Mars. This system is designed to facilitate communication and collaboration between researchers. Crater morphology databases will be archived through the U.S. Geological Survey in Flagstaff, where a comprehensive catalog of Martian crater morphologic information will be maintained.

  10. Martian cratering and central peak statistics - Mariner 9 results

    NASA Technical Reports Server (NTRS)

    Cordell, B. M.; Lingenfelter, R. E.; Schubert, G.

    1974-01-01

    Mariner 9 imagery shows that central peaked craters occur much more frequently in the Martian south polar region than in typical equatorial areas, and that both regions have crater size frequency distributions characteristic of saturation. Several arguments indicate that a preferential production mechanism, e.g., pingo formation made possible by subsurface permafrost confined to Martian polar regions, may account for the central peak excess in the south polar region.

  11. Clearing the Martian air - The troubled history of dust storms

    NASA Astrophysics Data System (ADS)

    Martin, L. J.

    1984-03-01

    This note is an attempt to resolve some misconceptions regarding the historical record of the Martian atmospheric phenomena referred to as 'dust storms,' but often called yellow storms, yellow clouds, planetwide dust storms, global dust storms, great dust storms, etc. The known frequency of planet-encircling storms will be specifically addressed. Better knowledge of the sizes, frequencies, and locations of Martian dust storms is needed for atmospheric modeling and for future mission planning.

  12. 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.

  13. [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

  14. 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.

  15. A thermal plume model for the Martian convective boundary layer

    NASA Astrophysics Data System (ADS)

    Colaïtis, A.; Spiga, A.; Hourdin, F.; Rio, C.; Forget, F.; Millour, E.

    2013-07-01

    The Martian planetary boundary layer (PBL) is a crucial component of the Martian climate system. Global climate models (GCMs) and mesoscale models (MMs) lack the resolution to predict PBL mixing which is therefore parameterized. Here we propose to adapt the "thermal plume" model, recently developed for Earth climate modeling, to Martian GCMs, MMs, and single-column models. The aim of this physically based parameterization is to represent the effect of organized turbulent structures (updrafts and downdrafts) on the daytime PBL transport, as it is resolved in large-eddy simulations (LESs). We find that the terrestrial thermal plume model needs to be modified to satisfyingly account for deep turbulent plumes found in the Martian convective PBL. Our Martian thermal plume model qualitatively and quantitatively reproduces the thermal structure of the daytime PBL on Mars: superadiabatic near-surface layer, mixing layer, and overshoot region at PBL top. This model is coupled to surface layer parameterizations taking into account stability and turbulent gustiness to calculate surface-atmosphere fluxes. Those new parameterizations for the surface and mixed layers are validated against near-surface lander measurements. Using a thermal plume model moreover enables a first-order estimation of key turbulent quantities (e.g., PBL height and convective plume velocity) in Martian GCMs and MMs without having to run costly LESs.

  16. 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

  17. Identification of Martian Cave Skylights Using the Temperature Change During Day and Night

    NASA Astrophysics Data System (ADS)

    Jung, Jongil; Yi, Yu; Kim, Eojin

    2014-06-01

    Recently, cave candidates have been discovered on other planets besides the Earth, such as the Moon and Mars. When we go to other planets, caves could be possible human habitats providing natural protection from cosmic threats. In this study, seven cave candidates have been found on Pavonis Mons and Ascraeus Mons in Tharsis Montes on Mars. The cave candidates were selected using the images of the Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO). The Context Camera could provide images with the high resolution of 6 meter per pixel. The diameter of the candidates ranges from 50 to 100m. Cushing et al. (2007) have analyzed the temperature change at daytime and nighttime using the Thermal Emission Imaging System (THEMIS) for the sites of potential cave candidates. Similarly, we have examined the temperature change at daytime and at nighttime for seven cave candidates using the method of Cushing et al. (2007). Among those, only one candidate showed a distinct temperature change. However, we cannot verify a cave based on the temperature change only and further study is required for the improvement of this method to identify caves more clearly.

  18. 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.

  19. 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

  20. The Martian Dust Cycle: Observations and Modeling

    NASA Technical Reports Server (NTRS)

    Kahre, Melinda A.

    2013-01-01

    The dust cycle is critically important for Mars' current climate system. Suspended atmospheric dust affects the radiative balance of the atmosphere, and thus greatly influences the thermal and dynamical state of the atmosphere. Evidence for the presence of dust in the Martian atmosphere can be traced back to yellow clouds telescopically observed as early as the early 19th century. The Mariner 9 orbiter arrived at Mars in November of 1971 to find a planet completely enshrouded in airborne dust. Since that time, the exchange of dust between the planet's surface and atmosphere and the role of airborne dust on Mars' weather and climate has been studied using observations and numerical models. The goal of this talk is to give an overview of the observations and to discuss the successes and challenges associated with modeling the dust cycle. Dust raising events on Mars range in size from meters to hundreds of kilometers. During some years, regional storms merge to produce hemispheric or planet encircling dust clouds that obscure the surface and raise atmospheric temperatures by tens of kelvin. The interannual variability of planet encircling dust storms is poorly understood. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. A low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading are generally observed: one peak occurs before northern winter solstice and one peak occurs after northern winter solstice. Numerical modeling studies attempting to interactively simulate the Martian dust cycle with general circulation models (GCMs) include the lifting, transport, and sedimentation of radiatively active dust. Two dust lifting processes are commonly represented in

  1. 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

  2. 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

  3. Northwest Africa 8159: New Type of Martian Meteorite

    NASA Astrophysics Data System (ADS)

    Agee, C. B.; Muttik, N.; Ziegler, K. G.; Walton, E. L.; Herd, C. D. K.; McCubbin, F. M.; Santos, A. R.; Simon, J. I.

    2014-12-01

    Up until recently the orthopyroxenite ALH 84001 and basaltic breccia NWA 7034 were the only martian meteorites that did not fit within the common SNC types. However with the discovery of Northwest Africa (NWA) 8159, the diversity is expanded further with a third unique non-SNC meteorite type. The existence of meteorite types beyond the narrow range seen in SNCs is what might be expected from a random cratering sampling of a volcanically long-lived and geologically complex planet such as Mars. NWA 8159, a fine-grained, augite basalt, is a new type of martian meteorite, with SNC-like oxygen isotopes and Fe/Mn values, but having several characteristics that make it distinct from other known martian meteorite types. NWA 8159 is the only martian basalt type known to have augite as the sole pyroxene phase in its mineralogy. NWA 8159 is unique among martian meteorites in that it possesses both crystalline plagioclase and shock amorphized plagioclase, often observed within a single grain, the bracketing of plagioclase amorphization places the estimated peak shock pressures at >15 GPa and <23 GPa. Magnetite in NWA 8159 is exceptionally pure, whereas most martian meteorites contain solid-solution titano-magnetites, and this pure magnetite is a manifestation of the highest oxygen fugacity (fO2) yet observed in a martian meteorite. Although NWA 8159 has the highest fO2 of martian meteorites, it has a pronounced light rare earth (LREE) depletion pattern similar to that of very low fO2 basaltic shergottites such as QUE 94201. Thus NWA 8159 displays a striking exception to well documented correlation between fO2 and LREE patterns in SNC meteorites. Finally, NWA 8159 stands apart from other martian meteorites in that it has an an early Amazonian age that is not represented in the SNCs, ALH 84001, or the NWA 7034 pairing group. NWA 8159 appears to be from an eruptive flow or shallow intrusion that is petrologically distinct from shergottite basalts, and its crystallization age

  4. Great Kobuk Sand Dunes, Alaska: A Terrestrial Analog Site for Polar, Topographically Confined Martian Dune Fields

    NASA Astrophysics Data System (ADS)

    Dinwiddie, C. L.; Hooper, D. M.; Michaels, T. I.; McGinnis, R. N.; Stillman, D.; Bjella, K.; Stothoff, S.; Walter, G. R.; Necsoiu, M.; Grimm, R. E.

    2010-12-01

    Martian dune systems belong to two broad categories: (i) the sprawling north polar erg, rich in and immobilized by seasonal and perennial volatiles; and (ii) isolated low- to high-latitude dune fields confined by topography. While modern dune migration on Mars is nearly imperceptibly slow, recent studies are producing robust evidence for aeolian activity, including bedform modification. Cold-climate terrestrial dunes containing volatile reservoirs provide an important analog to Martian polar dunes because permafrost and seasonal cycles of CO2 and H2O frost mantling are thought to partially decouple Martian polar dunes from atmospheric forcing. The 67°N latitude, 62 km2 Great Kobuk Sand Dunes (GKSD) are a terrestrial analog for polar, intercrater dune fields on Mars. Formative winds affected by complex topography and the presence of volatiles and intercalated snow within the GKSD have direct analogy to factors that impede migration of Martian polar dunes. This system offers the opportunity to study cold-climate, noncoastal, topographically constrained, climbing and reversing barchanoid, transverse, longitudinal, and star dunes. The Kobuk Valley climate is subarctic and semiarid with long, cold winters and brief, warm summers. Niveoaeolian sedimentation occurs within west-facing lee slope catchments. In March 2010, we found the seasonally frozen layer to range in thickness from 1.5 to 4.0 m, and no evidence for shallow permafrost. Instead, using GPR and boreholes, we found a system-wide groundwater aquifer that nearly parallels topography and cuts across steeply dipping bedforms. GPR cannot uniquely detect ice and water; however, a similar analysis of rover-based GPR might be used to detect volatiles in Martian dunes. The perennial volatile reservoir is liquid because of mean annual air temperature, intense solar heating before, during, and after 38 days of continuous summer daylight, high dry sand thermal conductivity, higher wet sand thermal conductivity

  5. 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.

  6. Magnetic properties of Martian surface material

    NASA Technical Reports Server (NTRS)

    Hargraves, R. B.

    1984-01-01

    The hypothesis that the magnetic properties of the Martian surface material are due to the production of a magnetic phase in the clay mineral nontronite by transient shock heating is examined. In the course of the investigation a magnetic material is produced with rather unusual properties. Heating from 900 C to 1000 C, of natural samples of nontronite leads first to the production of what appears to be Si doped maghemite gamma (-Fe2O3). Although apparently metastable, the growth of gamma -Fe2O3 at these temprtures is unexpected, and its relative persistence of several hours at 1000 C is most surprising. Continued annealing of this material for longer periods promote the crystallization of alpha Fe2O3 and cristobalite (high temperature polymorph of SiO2). All available data correlate this new magnetic material with the cristobalite hence our naming it magnetic ferri cristobalite. Formation of this magnetic cristobalite, however, may require topotactic growth from a smectite precursor.

  7. Possible Martian brines: Radar observations and models

    SciTech Connect

    Zent, A.P.; Fanale, F.P. ); Roth, L.E. )

    1990-08-30

    The 1971 and 1973 Goldstone 12.6-cm radar observations of Mars are separate data sets which include reflectivity as a function of latitude, longitude, and season. It has been argued that secular reflectivity variations of Mars' surface are indicated by the data and that shallow subsurface melting is the causal mechanism most compatible with the observations; however, the melting hypothesis conflicts with accepted notions of the state and distribution of water on Mars. The authors examine the data to identify temporal and spatial domains within which statistically significant changes in measured reflectivity are clustered. A few reflectivity changes may be genuine; others may be due to ephemeris errors or binning during data reduction. Brines which might satisfy the best supported reflectivity variations are out of equilibrium with the chemical megaenvironment. It is unclear whether such a brine, if emplaced in the Martian regolith at a depth shallow enough to affect the radar reflectivity, could survive even a single freeze-thaw cycle. They suggest that some combination of unique scattering properties or some as yet unidentified process other than melting is responsible for any genuine reflectivity variations.

  8. The heating environment during Martian atmospheric descent

    NASA Technical Reports Server (NTRS)

    Tauber, Michael E.; Yang, Lily

    1988-01-01

    It has been shown that a vehicle with a lift/drag ratio of 2.3 entering the Martian atmosphere at parabolic speed of 5 km/sec, or from a low orbit at 3.5 km/sec, has a very large landing footprint. At the 5-km/sec entry speed, the trajectory exhibits large skipping motions; however, a lateral range of up to 3300 km is attainable. The entries from low satellite orbit yield a gliding lateral range of 2500 km. The distances correspond to latitude changes of 57 and 42 deg, respectively. The high-speed, skipping entries were accompanied by the most intense heating. The peak stagnation point convective rates varied from 59 W/sq cm to 88 W/sq cm for partially and fully catalytic walls, respectively; the corresponding equilibrium wall temperatures were 1900 K and 2100 K. The peak heating at a wing leading-edge point reached 50 W/sq cm because of the presence of a transitional boundary layer. The lower-speed, gliding entries experienced much milder heating with a peak stagnation point rate of about 14 W/sq cm, resulting in a wall temperature near 1300 K. However, the longer duration of the gliding entries resulted in comparable heat loads for both entry speeds. The highest heat loads approached values experienced by the Shuttle orbiter stagnation point during a typical entry.

  9. 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.

  10. 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.

  11. Cold Ion Escape from the Martian Ionosphere

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    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 coldionospheric 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 to 2014 at 2.9±0.2×10 25 atoms/s which is in good agreement with model estimates. In this talk we will also try to compare these results with more recent observations by the MAVEN spacecraft. Possible mechanism to generate this flux can be the ionospheric pressure gradient between dayside and nightside or momentum transfer from the solar wind via the induced magnetic field since the flow velocity is in the Alfvénic regime.

  12. 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.

  13. Possible Martian brines - Radar observations and models

    NASA Technical Reports Server (NTRS)

    Zent, Aaron P.; Fanale, Fraser P.; Roth, Ladislav E.

    1990-01-01

    The 1971 and 1973 Goldstone 12.6-cm radar observations of Mars are separate data sets which include reflectivity as a function of latitude, longitude, and season. It has been argued that secular reflectivity variations of Mars' surface are indicated by the data and that shallow subsurface melting is the causal mechanism most compatible with the observations; however, the melting hypothesis conflicts with accepted notions of the state and distribution of water on Mars. The data are examined to identify temporal and spatial domains within which statistically significant changes in measured reflectivity are clustered. Brines which might satisfy the best supported reflectivity variations are out of equilibrium with the chemical megaenvironment. It is unclear whether such a brine, if emplaced in the Martian regolith at a depth shallow enough to affect the radar reflectivity, could survive even a single freeze-thaw cycle. Some combination of unique scattering properties or some as yet unidentified process other than melting is responsible for any genuine reflectivity variations.

  14. Secondary electron emission from Martian soil simulant

    NASA Astrophysics Data System (ADS)

    Pavlů, J.; Beránek, M.; Vaverka, J.; Å afránková, J.; Němeček, Z.; Richterová, I.

    2014-01-01

    In the recent years, growing interest in dust charging physics is connected with several lander missions running on or planned to the Moon, Mars, and Mercury for a near future. In support of these missions, laboratory simulations are a potential tool to optimize in situ exploration and measurements. In the paper, we have investigated electrical properties of a Martian soil simulant prepared at the Johnson Space Center under name JSC Mars-1 using the dust charging experiment when a single dust grain is trapped in a vacuum chamber and its secondary electron emission is studied. The exposure of the grain to the electron beam revealed that the grain surface potential is low and generally determined by a mean atomic number of the grain material at a low-energy range (<1 keV), whereas it can reach a limit of the field ion emission being irradiated by more energetic electrons. A comparison of model and experimental results reveals an influence of the grain shape and size predominantly in the range of higher (>2 keV) electron energies. We discuss possible implications of the secondary electron emission for the presence of lightnings on Mars.

  15. Martian paleolakes and waterways: Exobiological implications

    USGS Publications Warehouse

    Scott, D.H.; Rice, J. W., Jr.; 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Electric field generation in martian dust devils

    NASA Astrophysics Data System (ADS)

    Barth, Erika L.; Farrell, William M.; Rafkin, Scot C. R.

    2016-04-01

    Terrestrial dust devils are known to generate electric fields from the vertical separation of charged dust particles. The particles present within the dust devils on Mars may also be subject to similar charging processes and so likely contribute to electric field generation there as well. However, to date, no Mars in situ instrumentation has been deployed to measure electric field strength. In order to explore the electric environment of dust devils on Mars, the triboelectric dust charging physics from the Macroscopic Triboelectric Simulation (MTS) code has been coupled to the Mars Regional Atmospheric Modeling System (MRAMS). Using this model, we examine how macroscopic electric fields are generated within martian dust disturbances and attempt to quantify the time evolution of the electrodynamical system. Electric fields peak for several minutes within the dust devil simulations. The magnitude of the electric field is a strong function of the size of the particles present, the average charge on the particles and the number of particles lifted. Varying these parameters results in peak electric fields between tens of millivolts per meter and tens of kilovolts per meter.

  1. Characterization of Dark Streaks on Martian Slopes

    NASA Astrophysics Data System (ADS)

    Fenton, L. K.; Danielson, G. E.; Albee, A.; MGS MOC Science Team

    1998-09-01

    The narrow angle MOC images from the Mars Global Surveyor (MGS) show dozens of examples of dark streaks on Martian hillsides that may be indicative of fluid flow. In many cases multiple streaks seem to initiate from a narrow layer near the tops of steep slopes. They appear from these layers as narrow features that quickly broaden and then either remain the same width downhill or narrow and disappear. The largest streak observed to date is approximately 2 km in length and 100 m in width. MOLA data is not yet available to determine the slope down the length of the streaks. The lack of variation in brightness downhill and across the streaks shows that the formation of each streak occurred quickly. The streaks are widely distributed globally, but seem to be confined to layered materials. The streaks' characteristics show not only that the material forming them moved rapidly downslope but also that the streak material originated within the nearby bedrock. Change in brightness from one streak to another provides relative streak ages, assuming that dust infall causes an increase in streak albedo. The dark streaks are caused by a process that appears similar to fluid flow at the resolution of the MOC images. Possible causes of the streaks are water flow, lava flow, and debris flow. Our results are not yet conclusive as to the origins of the dark streaks, but we narrow the range of possible formation processes.

  2. Magnetic properties of Martian surface material

    NASA Astrophysics Data System (ADS)

    Hargraves, R. B.

    1984-06-01

    The hypothesis that the magnetic properties of the Martian surface material are due to the production of a magnetic phase in the clay mineral nontronite by transient shock heating is examined. In the course of the investigation a magnetic material is produced with rather unusual properties. Heating from 900 C to 1000 C, of natural samples of nontronite leads first to the production of what appears to be Si doped maghemite gamma (-Fe2O3). Although apparently metastable, the growth of gamma -Fe2O3 at these temprtures is unexpected, and its relative persistence of several hours at 1000 C is most surprising. Continued annealing of this material for longer periods promote the crystallization of alpha Fe2O3 and cristobalite (high temperature polymorph of SiO2). All available data correlate this new magnetic material with the cristobalite hence our naming it magnetic ferri cristobalite. Formation of this magnetic cristobalite, however, may require topotactic growth from a smectite precursor.

  3. Determining Catalytic Cycles in the Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Stock, Joachim; Boxe, Christopher; Grenfell, Lee; Lehmann, Ralph; Patzer, Beate; Rauer, Heike; Yung, Yuk

    2010-05-01

    Chemical trace species play an important role in the chemical composition of terrestrial planetary atmospheres. These species can operate in catalytic cycles, which critically affect the concentrations of major chemical constituents and hence the whole structure of the atmosphere itself. The determination of chemical pathways in such complex systems is generally a challenging task, so effective methods are desirable for the investigation of such problems. In order to address this question to the chemical catalytic cycles in the atmosphere of Mars, we use a new analysis tool (Pathway Analysis Program - PAP), which was originally developed and applied to automatically identify and quantify ozone and methane cycles in Earth's stratosphere. The implemented algorithm determines and quantifies all significant pathways by treating each species one after the other as a branching point. Pathways are formed by connecting shorter pathways producing those branching point species with pathways consuming them. Reaction rates are assigned to the pathways proportional to the branching probabilities. In order to identify and analyze the dominant chemical processes in the Martian atmosphere, we apply PAP to the CalTech photochemical column model. The methodology of the algorithm is presented and first results of our analysis are discussed in view of the relevant chemical trace species.

  4. 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.

  5. 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.

  6. 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.

  7. Determining the modal mineralogy of Martian soils

    NASA Astrophysics Data System (ADS)

    McSween, Harry Y.; McGlynn, Ian O.; Rogers, A. Deane

    2010-12-01

    A method for identifying the major and minor minerals and quantifying their proportions (by weight) in soils at the Mars Exploration Rovers landing sites is presented. The procedure utilizes modeled Mössbauer data for iron-bearing minerals, chemical calculations of Alpha Particle X-ray Spectrometer data for iron-absent minerals, and modeling of MiniTES thermal infrared spectra for silica and clays. Two models are formulated, using different assumptions about the mineralogy of sulfur and chlorine: sulfate + chloride, or incorporated in or adsorbed onto schwertmannite + akaganeite. The actual soil mineralogy may be bracketed by these results. Using either model, average dark soils on the Gusev crater plains and on Meridiani Planum are shown to be composed of a mixture of igneous (olivine, pyroxene, plagioclase, Fe-Ti-Cr spinels, phosphate) and alteration (amorphous silica, hematite, nanophase oxides, clays, plus sulfate + chloride or oxysulfate + oxychloride) minerals. This assemblage suggests that soil alteration did not occur in situ and that the igneous and alteration components were likely derived from different sources. The (model dependent) mixing ratio of igneous and alteration components is identical at the two sites on opposite sides of the planet, implying that Martian soils may provide a representative mineralogical sampling of the exposed crust.

  8. 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.

  9. Ephemeral Liquid Water at the Surface of Martian North Polar Cap

    NASA Astrophysics Data System (ADS)

    Losiak, Anna; Czechowski, Leszek; Velbel, Michael A.

    2015-04-01

    Formation of large, young gypsum deposits within the Olympia Planum region has been an unsolved riddle since its discovery [1]. It was proposed that gypsum was formed by precipitation of water emanating from polar layered deposits [2]. However, it is improbable that a large amount of bulk water could exist under current Martian low atmospheric pressure sufficiently long to form the observed deposits [3]. One of the proposed solutions to this problem is that gypsum is formed due to weathering in the ice [3, 4, 5, 6]. However none of the previous papers have described this process in detail, tested whether it is possible under current Martian conditions, and defined the environmental properties required for this process to occur. The aim of this paper is to determine if solar irradiation available currently at the North Polar Cap (NPC) is sufficient to heat a basaltic dust grain enough to melt a thin layer of glacial ice located directly beneath it. The numerical model used here is based on a one dimensional, time-dependent equation of heat transfer [8]. The model is applicable for grains exposed on the south-facing side of the NPC spiral troughs, during the warmest days of the year (with average or low amount of dust in the atmosphere), when surface temperature reaches 215 K and solar radiation delivers >260 W m^-2 (on the inclined surface). Our calculations show that during the warmest days of summer, pure water-ice located below a dark dust particle lying on the equatorial-facing slopes of the Martian NPC can be melted. Melting occurs over a wide range of used parameters which shows that this phenomenon is relatively common (albeit localized). Our research shows that on the Martian NPC there can be a sufficient amount of transient, metastable liquid water for evaporites such as gypsum to form, as was hypothesized by [3, 4, 5, 6]. Additionally, bulk water surrounding dust grains near the surface and precipitating evaporitic minerals makes the NPC one of the most

  10. Pulmonary Toxicity Study of Lunar and Martian Dust Simulants Intratracheally Instilled in Mice

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-Wing; James, John T.; Latch, John A.; Holian, A.; McCluskey, R.

    2000-01-01

    NASA is contemplating sending humans to Mars and the Moon for further exploration. The properties of Hawaiian and Californian volcanic ashes allow them to be used to simulate Martian and lunar dusts, respectively. NASA laboratories use these dust simulants to test performance of hardware destined for Martian or lunar environments. Workers in these test facilities are exposed to low levels of these dusts. The present study was conducted to investigate the toxicity of these dust simulants. Particles of respirable-size ranges of lunar simulant (LS), Martian simulant (MS), TiO2 (negative control) and quartz (positive control) were each intratracheally instilled (saline as vehicle) to groups of 4 mice (C57BL, male, 2-3 month old) at a single treatment of 1 (Hi dose) or 0.1 (Lo dose) mg/mouse. The lungs were harvested at the end of 7 days or 90 days for histopathological examination. Lungs of the LS-Lo groups had no evidence of inflammation, edema or fibrosis. The LS-Hi-7d group had mild to moderate acute inflammation, and neutrophilic and lymphocytic infiltration; the LS-Hi-90d group showed signs of chronic inflammation and some fibrosis. Lungs of the MS-Lo-7d group revealed mild inflammation and neutrophilic and lymphocytic infiltration; the MS-Lo-90d group showed mild fibrosis and particle-laden macrophages (PLM). Lungs of the MS-Hi-7d group demonstrated mild to moderate inflammation and large foci of PLM; the MS-Hi-90d group showed chronic mild to moderate inflammation and fibrosis. To mimic the effects of the oxidative and reactive properties of Martian soil surface, groups of mice were exposed to ozone (3 hour at 0.5 ppm) prior to MS dust instillation. Lung lesions in the MS group were more severe with the pretreatment. The results for the negative and positive controls were consistent with the known pulmonary toxicity of these compounds. The overall severity of toxic insults to the lungs were TiO2

  11. North-Polar Martian Cap as Habitat for Elementary Life

    NASA Astrophysics Data System (ADS)

    Wallis, M. K.; Wickramasinghe, J. T.; Wickramasinghe, N. C.

    2008-09-01

    through the dirt-encrusted ice cliff [7]. Thermal conduction through the dirt crust limits sublimation of underlying ice. This allows use of the thermal wave solution: where the thermal diffusivity α combining conductivity and specific heat is taken constant and τ0 = 1.88 yr is the martian year. As in [6] we adopt a sinusoidal temperature variation and take α = 0.0001 m²/hour. Like the martian ground ice case, the transition from dirt to ice is quite sharp. The surface temperature variation at the polar cap determined from local radiative balance is largely determined by albedo, while sublimation losses from a south-facing cliff are concentrated in the summer months. For fresh frost, the albedo is close to unity but values 0.6-0.8 allow for varying amounts of exposed dirt or dust, as explored in Figure 1. This shows the integrated ice loss over one martian year (687 Earth days) using the thermal wave solution and the Clausius-Clapeyron equation for ice sublimation: for T in degrees Kelvin. The solutions in Fig. 1 indicate a 10-15cm dirt crust develops quite quickly, within a few decades, becoming thick enough to choke back the sublimation rate to under 1mm/yr, compatible with the age of the cliffs. Less steep slopes develop rather thinner crusts. The seasonal thermal wave of Equ.1 applies for depths exceeding ~5cm (two diurnal skin depths). For A of 0.6, Fig. 1 shows a 10 cm thick crust builds up in ~30yr; this thick a crust may plausibly be maintained against weathering processes. If A<0.5, the mean temperature is too high for thermal inertia alone to choke the sublimation; the crust thickens to >10 cm within a few years and the self-sealing (deposition) and flow-retarding (adsorption/desorption) properties become significant in the thicker and hotter crust [5]. For A>0.7, a 5 cm crust cuts the sublimation rate to <0.1 mm/yr - we expect frost deposition to dominate, keeping the surface icy with high albedo for most of the diurnal cycle. The thermal lag due to latent

  12. When Every Day Is Professional Development Day

    ERIC Educational Resources Information Center

    Tienken, Christopher H.; Stonaker, Lew

    2007-01-01

    In the Monroe Township (New Jersey) Public Schools, teachers' learning occurs daily, not just on one day in October and February. Central office and school-level administrators foster job-embedded teacher growth. Every day is a professional development day in the district, but that has not always been so. How did the district become a system with…

  13. 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.

  14. Pulmonary Toxicity of Simulated Lunar and Martian Dusts Intratracheally Instilled into Mice

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-Wing; James, John; Holian, Andrij; Latch, Judith N.; Balis, John; Muro-Cacho, Carlos; Cowper, Shawn; McCluskey, Richard

    2000-01-01

    The National Aeronautics and Space Administration (NASA) is contemplating sending humans to Mars and to the Moon for further exploration. Equipment designated for these extraterrestrial bases will require testing in simulated Martian or lunar environments. The properties of Hawaiian and San Francisco Mountain volcanic ashes make them suitable to be used in these test environments as Martian and lunar dust simulants, respectively. The present toxicity study was conducted to address NASA's concern about the health risk of dust exposures in the test facilities. In addition, the results obtained on these simulants can be used to design a toxicity study of actual moon dust and Martian dust, which will probably be available in a few years. Respirable portions of lunar soil simulant (LSS) and Martian soil simulant (MSS) were separated from their respective raw materials. These soil simulants, together- with fine titanium dioxide (negative control for fibrogenesis in mice), and crystalline silica (positive control) were each intratracheally instilled in saline to groups of 4 male mice (C57BL/6J, 2-3 months old) at 0.1 mg/mouse (LD) or lmg/mouse (HD). The lungs were harvested 7 or 90 days after the single dust treatment for histopathological examination. Lungs of the LSS-LD groups on either the 7- or 90-day study showed no evidence of inflammation, edema, or fibrosis. Clumps of particles and an increased number of macrophages, visible in the lungs examined after 7 days, were absent after 90 days. The LSS-HD-7d group showed mild to moderate alveolitis with neutrophilic and lymphocytic infiltration, and mild perivascular and peribronchiolar inflammation. The LSS-HD-90d group showed signs of chronic inflammation: septal thickening, mild perivascular and peribronchiolar inflammation, mild alveolitis and some fibrosis. Foci of particle-laden macrophages (PLMs) were still visible. Lungs of the MSS-LD-7d group revealed mild focal intraalveolar inflammation with neutrophilic and

  15. Large-scale geometry and temporal variability of the Martian external magnetic field

    NASA Astrophysics Data System (ADS)

    Mittelholz, A.; Johnson, C. L.; Langlais, B.

    2014-12-01

    The martian magnetic field is unique among the terrestrial planets, as it results from the interaction of fields caused by crustal remnant magnetization and a planetary ionosphere with the solar wind and the interplanetary magnetic field. Internal fields of crustal origin have been subject to extensive studies, whereas the focus of our work deals with average spatial structure and time variability in the martian external magnetic field. We use the Mars Global Surveyor (MGS) vector magnetic field data to investigate the large-scale geometry and magnitude of such external fields. We analyze the day-time and night-time magnetic signature for the duration of the MGS mission in mapping orbit (2000-2006). We use along-track vector field measurements to estimate the day-time and night-time external fields after the subtraction of predicted crustal magnetic fields at spacecraft altitudes. We also examine day/night differences (i.e., the daily variation) in external fields; these are independent of crustal fields. Because the external fields are modified by the crustal fields, we investigate their structure as a function of latitude in the local time frame and as a function of both latitude and longitude in the body-fixed frame. In the body-fixed-frame BΘis generally dominant in magnitude with a day/night variation described to first order by a zonal degree-2 spherical harmonic structure. Br is strongly correlated with the crustal magnetic field. BΦ shows variable spatial behaviour during both night and day. Seasonal variations are observed as stronger average magnetic fields in the hemisphere pointing towards the sun. Additional shorter time scale variations in the global external field structure are observed.

  16. A global view of gravity waves in the Martian atmosphere inferred from a high-resolution general circulation model

    NASA Astrophysics Data System (ADS)

    Kuroda, Takeshi; Medvedev, Alexander S.; Yiǧit, Erdal; Hartogh, Paul

    2015-11-01

    Global characteristics of the small-scale gravity wave (GW) field in the Martian atmosphere obtained from a high-resolution general circulation model (GCM) are presented for the first time. The simulated GW-induced temperature variances are in a good agreement with available radio occultation data in the lower atmosphere between 10 and 30 km. The model reveals a latitudinal asymmetry with stronger wave generation in the winter hemisphere and two distinctive sources of GWs: mountainous regions and the meandering winter polar jet. Orographic GWs are filtered, while propagating upward, and the mesosphere is primarily dominated by harmonics with faster horizontal phase velocities. Wave fluxes are directed mainly against the local wind. GW dissipation in the upper mesosphere generates body forces of tens of m s-1 per Martian solar day (sol-1), which tend to close the simulated jets. The results represent a realistic surrogate for missing observations, which can be used for constraining GW parameterizations and validating GCM simulations.

  17. Martian Arctic Dust Devil and Phoenix Meteorology Mast

    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 vertical post near the left edge of this image is the mast of the Meteorological Station on Phoenix. The dust devil visible at the horizon just to the right of the mast is estimated to be 600 to 700 meters (about 2,000 to 2,300 feet) from Phoenix, and 4 to 5 meters (10 to 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.

  18. Methane storage capacity of the early martian cryosphere

    NASA Astrophysics Data System (ADS)

    Lasue, Jeremie; Quesnel, Yoann; Langlais, Benoit; Chassefière, Eric

    2015-11-01

    Methane is a key molecule to understand the habitability of Mars due to its possible biological origin and short atmospheric lifetime. Recent methane detections on Mars present a large variability that is probably due to relatively localized sources and sink processes yet unknown. In this study, we determine how much methane could have been abiotically produced by early Mars serpentinization processes that could also explain the observed martian remanent magnetic field. Under the assumption of a cold early Mars environment, a cryosphere could trap such methane as clathrates in stable form at depth. The extent and spatial distribution of these methane reservoirs have been calculated with respect to the magnetization distribution and other factors. We calculate that the maximum storage capacity of such a clathrate cryosphere is about 2.1 × 1019-2.2 × 1020 moles of CH4, which can explain sporadic releases of methane that have been observed on the surface of the planet during the past decade (∼1.2 × 109 moles). This amount of trapped methane is sufficient for similar sized releases to have happened yearly during the history of the planet. While the stability of such reservoirs depends on many factors that are poorly constrained, it is possible that they have remained trapped at depth until the present day. Due to the possible implications of methane detection for life and its influence on the atmospheric and climate processes on the planet, confirming the sporadic release of methane on Mars and the global distribution of its sources is one of the major goals of the current and next space missions to Mars.

  19. Evolution of Martian atmospheric argon: Implications for sources of volatiles

    NASA Astrophysics Data System (ADS)

    Hutchins, Kevin S.; Jakosky, Bruce M.

    We have examined processes affecting isotopes of argon (36Ar, 38Ar, 40Ar) in order to determine important atmospheric sources and sinks. Our simple model for argon evolution incorporates production of radiogenic argon in the mantle, outgassing of all argon species by extrusive and intrusive volcanism, and loss to space by knock-on sputtering above the exobase. Sputtering has been shown previously to be an important loss process for atmospheric species, especially isotopes of noble gases, which have few other mechanisms of escape. The integrated evolution of argon (36Ar, 38Ar, and 40Ar, respectively) is modeled in terms of these variables: (1) the planetary concentration of potassium, (2) the fraction of juvenile argon released catastrophically during the first 600 Myr., (3) potential variation in the time-history of sputtering loss from that suggested by Luhmann et al. [1992], and (4) the volume of total outgassing to the surface as compared to outgassing contributed by volcanic release. Our results indicate that Mars has lost between 85-95% of 36Ar and 70-88% of outgassed 40Ar. Due to this substantial loss, the planet must have outgassed the equivalent of between 10 and 100 times the total volume of gases released by extrusive and intrusive volcanics. This indicates that volcanic outgassing, alone, is insufficient to explain the present-day abundances of 36Ar and 40Ar in the Martian atmosphere. Similar calculations for 20Ne suggest outgassed volumes of between 100 and 1800 times in excess of that due to volcanism. This results in a distinct Ne/Ar elemental fractionation, with a preference for outgassing argon, of the order of 10 to 17. Although the results must be evaluated within the model uncertainties, the results are compelling in that they unequivocally show the existence of additional sources of atmospheric volatiles and helps define a means to identify them.

  20. 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.

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

    USGS Publications Warehouse

    Skinner, J.A., Jr.; 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.

  2. 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).

  3. Capture of Solar Wind He++ by the Martian Exosphere

    NASA Astrophysics Data System (ADS)

    Chanteur, G. M.; Modolo, R.; Dubinin, E.

    The quantity of helium in the Martian atmosphere can be estimated from its emission line at 58 4nm Krasnopolsky and Gladstone Icarus vol 176 395-407 2005 and references therein Considering the necessary balance between losses through escape to the interplanetary medium and sources Krasnopolsky and coworkers have established that radioactive decay of uranium and thorium provides only one third of the lost helium They argue that the remaining two thirds should be captured from the solar wind This external source of Martian helium was also suggested by Barabash et al JGR 100 A11 21307 1995 Brecht JGR 102 A6 11287 1997 has estimated the deposition of protons into the Martian atmosphere from 3d hybrid simulation of the interaction of Mars with a solar wind made of protons and electrons only From these results Brecht gave an estimate of the deposition of solar helium ions into the Martian atmosphere based on scaling arguments In the recent past we have developed a consistent multi-species 3d hybrid model of the interaction of solar wind protons and alpha particles with the Martian plasma environment taking into account the ionisation of the oxygen and hydrogen neutral coronas of Mars Modolo et al Ann Geophys 23 433 2005 Neutral species are ionised by photons and by electron impacts the two processes are simulated consistently and independently through the specification of ionisation frequencies and cross sections Charge exchange reactions of protons and oxygen ions with hydrogen and oxygen atoms are taken into account

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Martian Analogue Samples, Their Spectroscopic Biosignatures, and Degradation by the Cosmic Radiation Environment

    NASA Astrophysics Data System (ADS)

    Dartnell, L. R.

    2016-05-01

    Here we discuss the use of Raman and FTIR spectroscopy for the detection and characterisation of biosignatures in martian analogue samples, and their degradation by the cosmic ray environment in the martian near-subsurface.

  10. Experimental Study of Water Exchange Between Regolith and Atmosphere Under Martian Conditions: Thermodynamics and Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pommerol, A.; Schmitt, B.; Brissaud, O.

    2008-03-01

    We have designed a facility to measure near-infrared reflectance spectra of martian regolith analogs under martian surface temperature and humidity. We present adsorption isotherm and exchange kinetics between water and JSC Mars-1 regolith simulant.

  11. 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.

  12. 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

  13. Aqueous Alteration and Martian Bulk Chemical Composition

    NASA Astrophysics Data System (ADS)

    Taylor, J.; Boynton, W. V.; McLennan, S. M.

    2009-12-01

    The bulk compositions of the terrestrial planets are fundamentally important in testing models for planetary accretion. This is particularly true for the abundances of volatile elements. In the absence of direct samples of the mantle, we must rely on samples of surface materials obtained from orbit (specifically from the Mars Odyssey Gamma-Ray Spectrometer, GRS), Martian meteorites, and in situ analyses. Use of these databases requires understanding the processes that formed and modified the igneous rocks composing the crust; aqueous processes are particularly important. Halogens are useful elements for understanding Martian bulk composition and surface aqueous alteration. Here, we focus on Cl, which is an incompatible element during partial melting. Cosmochemically, Cl is a moderately volatile element with a condensation temperature of 948 Kelvin, only slightly below that of K (1006 Kelvin), another incompatible lithophile element. Cl is substantially lost during magma degassing at or near the surface, making it difficult to determine its abundances in the interior through analyses of rocks, leading to an underestimate of Cl abundance in bulk silicate Mars. GRS data for Mars between approximately 52 degrees north and south show that K and Cl are uncorrelated. This is not surprising as they fractionate easily by release of Cl-bearing gases from magmas near the surface and during eruptions, by aqueous alteration of surface materials, and by the large solubility of Cl salts in water. A positive correlation of Cl with H supports the role of water in Cl redistribution. In spite of the lack of correlation between K and Cl, the mean Cl/K ratio is roughly chondritic: 1.5 ±0.1 compared to 1.28 in CI chondrites. However, Cl appears to be enriched at least in the uppermost few tens of cm analyzed by the GRS: Cl correlates with both H and S, but a linear fit to the data shows a positive Cl intercept of about 0.3, which suggests a decoupling of Cl from S and H. Adjusting the

  14. 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.

  15. A lunar/Martian anchor emplacement system

    NASA Astrophysics Data System (ADS)

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

    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.

  16. 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.

  17. 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

  18. Cold Ion Escape from the Martian Ionosphere

    NASA Astrophysics Data System (ADS)

    Fränz, Markus; Dubinin, Eduard; Andrews, David; Nilsson, Hans; Fedorov, Andrei

    2014-05-01

    It has always been challenging to observe the flux of ions with energies of less than 10eV escaping from the planetary ionospheres. We here report on new measurements of the ionospheric ion flows at Mars by the ASPERA-3 experiment on board Mars Express. The ion sensor IMA of this experiment has in principle a low-energy cut-off at 10eV but in negative spacecraft charging cold ions are lifted into the range of measurement but the field of view is restricted to about 4x360 deg. In a recent paper Nilsson et al. (Earth Planets Space, 64, 135, 2012) tried to use the method of long-time averaged distribution functions to overcome these constraints. In this paper we first use the same method to show that we get results consistent with this when using ASPERA-3 observations only. But then we can show that these results are inconsistent with observations of the local plasma density by the MARSIS radar instrument on board Mars Express. We demonstrate that the method of averaged distribution function can deliver the mean flow speed of the plasma but the low-energy cut-off does usually not allow to reconstruct the density. We then combine measurements of the cold ion flow speed with the plasma density observations of MARSIS to derive the cold ion flux. In an analysis of the combined nightside datasets we show that the main escape channel is along the shadow boundary on the tailside of Mars. At a distance of about 0.5 Martian radii the flux settles at a constant value which indicates that about half of the transterminator ionospheric flow escapes from the planet. Possible mechanism to generate this flux can be the ionospheric pressure gradient between dayside and nightside or momentum transfer from the solar wind via the induced magnetic field since the flow velocity is in the Alfvénic regime.

  19. The origin of the Martian moons revisited

    NASA Astrophysics Data System (ADS)

    Rosenblatt, Pascal

    2011-08-01

    The origin of the Martian moons, Phobos and Deimos, is still an open issue: either they are asteroids captured by Mars or they formed in situ from a circum-Mars debris disk. The capture scenario mainly relies on the remote-sensing observations of their surfaces, which suggest that the moon material is similar to outer-belt asteroid material. This scenario, however, requires high tidal dissipation rates inside the moons to account for their current orbits around Mars. Although the in situ formation scenarios have not been studied in great details, no observational constraints argue against them. Little attention has been paid to the internal structure of the moons, yet it is pertinent for explaining their origin. The low density of the moons indicates that their interior contains significant amounts of porous material and/or water ice. The porous content is estimated to be in the range of 30-60% of the volume for both moons. This high porosity enhances the tidal dissipation rate but not sufficiently to meet the requirement of the capture scenario. On the other hand, a large porosity is a natural consequence of re-accretion of debris at Mars' orbit, thus providing support to the in situ formation scenarios. The low density also allows for abundant water ice inside the moons, which might significantly increase the tidal dissipation rate in their interiors, possibly to a sufficient level for the capture scenario. Precise measurements of the rotation and gravity field of the moons are needed to tightly constrain their internal structure in order to help answering the question of the origin.

  20. 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.

  1. Morphogenesis of Antarctic Paleosols: Martian Analogue

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Dohm, J. M.; Baker, V. R.; Newsom, Horton E.; Malloch, D.; Hancock, R. G. V.; Campbell, Iain; Sheppard, D.; Milner, M. W.

    2001-11-01

    Samples of horizons in paleosols from the Quartermain Mountains of the Antarctic Dry Valleys (Aztec and New Mountain areas) were analyzed for their physical characteristics, mineralogy, chemical composition, and microbiology to determine the accumulation and movement of salts and other soluble constituents and the presence/absence of microbial populations. Salt concentrations are of special interest because they are considered to be a function of age, derived over time, in part from nearby oceanic and high-altitude atmospheric sources. The chemical composition of ancient Miocene-age paleosols in these areas is the direct result of the deposition and weathering of airborne-influxed salts and other materials, as well as the weathering of till derived principally from local dolerite and sandstone outcrops. Paleosols nearer the coast have greater contents of Cl, whereas near the inland ice sheet, nitrogen tends to increase on a relative basis. The accumulation and vertical distribution of salts and other soluble chemical elements indicate relative amounts of movement in the profile over long periods of time, in the order of several million years. Four of the six selected subsamples from paleosol horizons in two ancient soil profiles contained nil concentrations of bacteria and fungi. However, two horizons at depths of between 3 and 8 cm, in two profiles, yielded several colonies of the fungi Beauveria bassiana and Penicillium brevicompactum, indicating very minor input of organic carbon. Beauveria bassiana is often reported in association with insects and is used commercially for the biological control of some insect pests. Penicillium species are commonly isolated from Arctic, temperate, and tropical soils and are known to utilize a wide variety of organic carbon and nitrogen compounds. The cold, dry soils of the Antarctic bear a close resemblance to various present and past martian environments where similar weathering could occur and possible microbial populations

  2. 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.

  3. Superoxide Radical Lifetime on the Martian Surface

    NASA Astrophysics Data System (ADS)

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

    2005-08-01

    We have examined the formation and stability of the superoxide radical O2-, which has been hypothesized as a potential Mars oxidant. Rutile (TiO2) was heated to ˜ 400 degrees C under vacuum. The samples were tipped off in ampules under 8-9 torr O2, photolyzed with a Hg lamp for 30 minutes; EPR spectra were immediately obtained at 77K. The signature of O2- was clearly observed in the rutile. The sealed ampules were stored at room temperature for up to 2 weeks without any decrease in the number of spins. The same process, applied to rutile that was not baked out yielded superoxide signals that could not be detected once the photolyzing flux was cut off. To examine the effects of partial dehydration, we carried out the same series of experiments on rutile that was baked out at 200 degrees C. This material showed decay of superoxide spins to zero in less than 10 minutes. This qualitative pattern is also observed in experiments on anatase (Attwood, et al., , 2003). We hypothesize that O2- can be stabilized against reaction with H2O and OH by crystalline surface defects. On hydrated surfaces, O2- must compete for stabilizing sites, and the population is quickly extinguished; in dehydrated samples, it can migrate to stabilizing defects. Once sorbed, the O2- radical is stable in the presence of H2O. OMEGA Mars Express data (Poullet et al, 2005) suggest one to several percent adsorbed H2O across the Martian surface, which will significantly decrease O2- lifetime. One possibility for subsurface stabilization of O2- can be postulated based on EPR spectra of anatase, exposed to H2O2 in our lab in 1996, and which in 2005 shows the signature of O2-. Evidently, H2O2 can convert to stable O2- on some surfaces. This hypothesis might allow subsurface diffusion of H2O2, followed by conversion to O2-.

  4. The Martian ionosphere: comparison of a global climate model with MARSIS data

    NASA Astrophysics Data System (ADS)

    González-Galindo, F.; Němec, F.; López-Valverde, M. A.; Chaufray, J.-Y.; Forget, F.; Morgan, D. D.; Diéval, C.; Gurnett, D. A.

    2015-10-01

    We present here the comparison of the electron density profiles predicted by a 3D global climate model (GCM), the Mars GCM developed at the Laboratoire de Météorologie Dynamique (LMD-MGCM) [4], with the measurements from the instrument MARSIS on board Mars Express [5]. The observations were ob- tained during 5 Martian Years (MY), from MY27 to MY31 (mid 2005-end of 2013). The model was run using the observed day-to-day variability of the UV solar flux and of the dust load during that period. We focus the comparison on two parameters: the electron density at the main peak, and the altitude of the peak. Special attention will be paid to the variability of these two parameters with different geophysical parameters (latitude, SZA, ...), which can provide interesting information about the neutral upper atmosphere of Mars and its interaction with the UV solar radiation.

  5. A strong seasonal dependence in the Martian hydrogen exosphere

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Dolon; Clarke, John T.; Bertaux, Jean-Loup; Chaufray, Jean-Yves; Mayyasi, Majd

    2015-10-01

    Hubble Space Telescope and Mars Express observed unexpected rapid changes in the Martian hydrogen exosphere involving a decrease in scattered Lyman α intensity in fall 2007 (solar longitude, Ls = 331°-345°). These changes detected were speculated to be a combination of seasonal variation and/or dust storms and lower atmospheric dynamics. Here we present Hubble Space Telescope observations of Mars in 2014 over a broad range of heliocentric distances and seasons (Ls = 138°-232°) which indicate a factor of ~3.5 change in Martian Lyman α brightness associated with a factor of ~5.4 variation of hydrogen escape flux in the absence of global dust storms and significant solar variability. We thus conclude that seasonal effects have a strong influence on the hydrogen exosphere, which in turn has major implications for the processes that control water supply to the Martian upper atmosphere and the history of water escape from Mars.

  6. Pre-Global Surveyor evidence for Martian ground water

    PubMed Central

    Donahue, Thomas M.

    2001-01-01

    A time-dependent theory for the evolution of water on Mars is presented. Using this theory and invoking a large number of observational constraints, I argue that these constraints require that a large reservoir of water exists in the Martian crust at depths shallow enough to interact strongly with the atmosphere. The constraints include the abundance of atmospheric water vapor, escape fluxes of hydrogen and deuterium, D/H ratios in the atmosphere and in hydrous minerals found in one Martian meteorite, alteration of minerals in other meteorites, and fluvial features on the Martian surface. These results are consonant with visual evidence for recent groundwater seepage obtained by the Mars Global Surveyor satellite. PMID:11158555

  7. Pre-global surveyor evidence for Martian ground water.

    PubMed

    Donahue, T M

    2001-01-30

    A time-dependent theory for the evolution of water on Mars is presented. Using this theory and invoking a large number of observational constraints, I argue that these constraints require that a large reservoir of water exists in the Martian crust at depths shallow enough to interact strongly with the atmosphere. The constraints include the abundance of atmospheric water vapor, escape fluxes of hydrogen and deuterium, D/H ratios in the atmosphere and in hydrous minerals found in one Martian meteorite, alteration of minerals in other meteorites, and fluvial features on the Martian surface. These results are consonant with visual evidence for recent groundwater seepage obtained by the Mars Global Surveyor satellite. PMID:11158555

  8. On the original igneous source of Martian fines

    NASA Technical Reports Server (NTRS)

    Baird, A. K.; Clark, B. C.

    1981-01-01

    The composition of the silicate portion of Martian regolith fines indicates derivation of the fines from mafic to ultramafic rocks, probably rich in pyroxene. Rock types similar in chemical and mineralogical composition include terrestrial Archean basalts and certain achondrite meteorites. If these igneous rocks weathered nearly isochemically, the nontronitic clays proposed earlier as an analog to Martian fines could be formed. Flood basalts of pyroxenitic lavas may be widespread and characteristic of early volcanism on Mars, analogous to maria flood basalts on the moon and early Precambrian basaltic komatiites on earth. Compositional differences between lunar, terrestrial, and Martian flood basalts may be related to differences in planetary sizes and mantle compositions of the respective planetary objects.

  9. Triboelectric Charging of an Insulator's Surface Using Martian Soil Simulant

    NASA Astrophysics Data System (ADS)

    Mantovani, J. G.; Calle, C. I.; Groop, E. E.; Buehler, M. G.

    2000-11-01

    We have investigated the simultaneous triboelectric charging of five types of insulating materials under identical conditions using frictional contact with Martian soil simulant (JSC Mars-1). The insulators studied were fiberglass/epoxy, polycarbonate, teflon, Rulon J, and polymethylmethacrylate. The amount of electric charge that developed on each insulator's surface was measured simultaneously by five independent electrometer circuits contained in the Mars Environmental Compatibility Assessment (MECA) electrometer. This is a flight instrument designed at JPL and NASA Kennedy Space Center for a future robotic lander mission of the Martian surface. We will describe the proposed robotic operation of the MECA electrometer on Mars, and will present data that was taken with the electrometer at NASA KSC using Martian soil simulant at room temperature inside a vacuum chamber containing a CO2 atmosphere at a pressure of 7 Torr.

  10. 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.

  11. Organic Compounds in Martian Meteorites May Be Terrestrial Contaminants

    NASA Astrophysics Data System (ADS)

    Jull, A. J. T.

    1998-02-01

    In 1996, David McKay and coworkers reported evidence suggesting the possibility of fossils in the Martian meteorite ALH84001 (see PSRD article "Life on Mars"). This work has stimulated much discussion as to the nature and origin of organic material in ALH84001, another Martian meteorite, EET79001, and other Martian meteorites in general. My colleagues C. Courtney, D. A. Jeffrey, and J. W. Beck and I have been investigating the origin of the organic compounds by measuring the abundances of the isotopes of carbon (C) using accelerator mass spectrometry (AMS). Important clues to the origin of the organic material can be obtained from the amounts of 14C (frequently nicknamed radiocarbon) and the relative amounts of 13C and 12C. Our analyses indicate that at least 80% of the organic material in ALH84001 is from Earth, not Mars, casting doubt on the hypothesis the meteorite contains a record of fossil life on Mars.

  12. Helium in the Martian atmosphere - Thermal loss considerations

    NASA Technical Reports Server (NTRS)

    Levine, J. S.; Keating, G. M.; Prior, E. J.

    1974-01-01

    Helium concentrations in the Martian atmosphere are estimated assuming that the helium production on Mars (comparable to its production on earth) via the radioactive decay of uranium and thorium is in steady state equilibrium with its thermal escape. Although nonthermal losses would tend to reduce the estimated concentrations, these concentrations are not necessarily an upper limit since higher production rates and/or a possibly lower effective exospheric temperature over the solar activity cycle could increase them to even higher values. The computed helium concentration at the Martian exobase (200 km) is 8 million atoms/cu cm. Through the lower exosphere, the computed helium concentrations are 30-200 times greater than the Mariner-measured atomic hydrogen concentrations. It follows that helium may be the predominant constituent in the Martian lower exosphere and may well control the orbital lifetime of Mars-orbiting spacecraft.

  13. 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.

  14. Extended Survival of Several Microorganisms and Relevant Amino Acid Biomarkers under Simulated Martian Surface Conditions as a Function of Burial Depth

    SciTech Connect

    Johnson, Adam; Pratt, L.M.; Vishnivetskaya, Tatiana A; Pfiffner, S. M.; Bryan, R. A.; Dadachova, E.; Whyte, L G; Radtke, K.; Chan, E.; Tronick, S.; Borgonie, G.; Mancinelli, R.; Rothschild, L.; Rogoff, D.; Horikawa, D. D.; Onstott, T. C.

    2011-01-01

    Recent orbital and landed missions have provided substantial evidence for ancient liquid water on the martian surface as well as evidence of more recent sedimentary deposits formed by water and/or ice. These observations raise serious questions regarding an independent origin and evolution of life on Mars. Future missions seek to identify signs of extinct martian biota in the form of biomarkers or morphological characteristics, but the inherent danger of spacecraft-borne terrestrial life makes the possibility of forward contamination a serious threat not only to the life detection experiments, but also to any extant martian ecosystem. A variety of cold and desiccation-tolerant organisms were exposed to 40 days of simulated martian surface conditions while embedded within several centimeters of regolith simulant in order to ascertain the plausibility of such organisms survival as a function of environmental parameters and burial depth. Relevant amino acid biomarkers associated with terrestrial life were also analyzed in order to understand the feasibility of detecting chemical evidence for previous biological activity. Results indicate that stresses due to desiccation and oxidation were the primary deterrent to organism survival, and that the effects of UV-associated damage, diurnal temperature variations, and reactive atmospheric species were minimal. Organisms with resistance to desiccation and radiation environments showed increased levels of survival after the experiment compared to organisms characterized as psychrotolerant. Amino acid analysis indicated the presence of an oxidation mechanism that migrated downward through the samples during the course of the experiment and likely represents the formation of various oxidizing species at mineral surfaces as water vapor diffused through the regolith. Current sterilization protocols may specifically select for organisms best adapted to survival at the martian surface, namely species that show tolerance to radical

  15. 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

  16. 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.

  17. 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.

  18. Shergottite Impact Melt Glasses Contain Soil from Martian Uplands

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Martian meteorite (shergottite) impact melt glasses that contain high concentrations of martian atmospheric noble gases and show significant variations in Sr-87/Sr-86 isotopic ratios are likely to contain Martian surface fines mixed with coarser regolith materials. The mixed soil constituents were molten due to shock at the time of meteoroid impact near the Martian surface and the molten glass got incorporated into the voids and cracks in some shergottite meteorites. Earlier, Rao et al. found large enrichments of sulfur (sulfate) during an electron-microprobe study of several impact melt glass veins and pods in EET79001,LithC thin sections. As sulfur is very abundant in Martian soil, these S excesses were attributed to the mixing of a soil component containing aqueously altered secondary minerals with the LithC precursor materials prior to impact melt generation. Recently, we studied additional impact melt glasses in two basaltic shergottites, Zagami and Shergotty using procedures similar to those described. Significant S enrichments in Zagami and Shergotty impact melt glass veins similar to the EET79001, LithC glasses were found. In addition, we noticed the depletion of the mafic component accompanied by the enrichment of felsic component in these impact melt glass veins relative to the bulk host rock in the shergottites. To explain these observations, we present a model based on comminution of basaltic rocks due to meteoroid bombardment on martian regolith and mechanical fractionation leading to enrichment of felsics and depletion of mafics in the fine grained dust which is locally mobilized as a result of saltation and deflation due to the pervasive aeolian activity on Mars.

  19. Shergottite Impact Melt Glasses Contain Soil from Martian Uplands

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Martian meteorite (shergottite) impact melt glasses that contain high concentrations of martian atmospheric noble gases and show significant variations in Sr-87/Sr-86 isotopic ratios are likely to contain Martian surface fines mixed with coarser regolith materials. The mixed soil constituents were molten due to shock at the time of meteoroid impact near the Martian surface and the molten glass got incorporated into the voids and cracks in some shergottite meteorites. Earlier, Rao et al. found large enrichments of sulfur (sulfate) during an electron-microprobe study of several impact melt glass veins and pods in EET79001,LithC thin sections. As sulfur is very abundant in Martian soil, these S excesses were attributed to the mixing of a soil component containing aqueously altered secondary minerals with the LithC precursor materials prior to impact melt generation. Recently, we studied additional impact melt glasses in two basaltic shergottites, Zagami and Shergotty using procedures similar to those described by Rao et al. Significant S enrichments in Zagami and Shergotty impact melt glass veins similar to the EET79001, LithC glasses were found. In addition, we noticed the depletion of the mafic component accompanied by the enrichment of felsic component in these impact melt glass veins relative to the bulk host rock in the shergottites. To explain these observations, we present a model based on comminution of basaltic rocks due to meteroid bombardment on martian regolith and mechanical fractionation leading to enrichment of felsics and depletion of mafics in the fine grained dust which is locally mobilized as a result of saltation and deflation due to the pervasive aeolian activity on Mars.

  20. 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.

  1. Martian weathering processes: Terrestrial analog and theoretical modeling studies

    NASA Astrophysics Data System (ADS)

    McAdam, Amy Catherine

    2008-06-01

    Understanding the role of water in the Martian near-surface, and its implications for possible habitable environments, is among the highest priorities of NASA's Mars Exploration Program. Characterization of alteration signatures in surface materials provides the best opportunity to assess the role of water on Mars. This dissertation investigates Martian alteration processes through analyses of Antarctic analogs and numerical modeling of mineral-fluid interactions. Analog work involved studying an Antarctic diabase, and associated soils, as Mars analogs to understand weathering processes in cold, dry environments. The soils are dominated by primary basaltic minerals, but also contain phyllosilicates, salts, iron oxides/oxyhydroxides, and zeolites. Soil clay minerals and zeolites, formed primarily during deuteric or hydrothermal alteration of the parent rock, were subsequently transferred to the soil by physical rock weathering. Authigenic soil iron oxides/oxyhydroxides and small amounts of poorly-ordered secondary silicates indicate some contributions from low-temperature aqueous weathering. Soil sulfates, which exhibit a sulfate- aerosol-derived mass-independent oxygen isotope signature, suggest contributions from acid aerosol-rock interactions. The complex alteration history of the Antarctic materials resulted in several similarities to Martian materials. The processes that affected the analogs, including deuteric/ hydrothermal clay formation, may be important in producing Martian surface materials. Theoretical modeling focused on investigating the alteration of Martian rocks under acidic conditions and using modeling results to interpret Martian observations. Kinetic modeling of the dissolution of plagioclase-pyroxene mineral mixtures under acidic conditions suggested that surfaces with high plagioclase/pyroxene, such as several northern regions, could have experienced some preferential dissolution of pyroxenes at a pH less than approximately 3-4. Modeling of the

  2. 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.

  3. Martian induced magnetosphere variations with solar activity cycle

    NASA Astrophysics Data System (ADS)

    Fedorov, Andrey; Ronan, Modolo; Jarninen, Riku; Mazelle, Christian; Barabash, Stas

    2014-05-01

    During the last 6 years of ESA Mars Express mission we have accumulated plasma data taken inside and around the Martian induced magnetosphere corresponding to the increasing branch of solar activity. This data allows to make an enhanced study of the magnetosphere variations as a response of the solar activity level. Since Mars Express has no onboard magnetometer, we used the hybrid models of the Martian plasma environment to get a proper frame to make an adequate statistics of the magnetospheric response. In this paper we present a spatial distribution of the planetary plasma in the planetary wake as well as the ionsospheric escape as a function of the solar activity.

  4. 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.

  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

    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.

  8. Schoolwide Literacy Days.

    ERIC Educational Resources Information Center

    Polder, Darlene D.

    2000-01-01

    Describes 10 "literacy day" activities that one California elementary school has used successfully schoolwide, typically one such day per month, to make reading fun and purposeful, while developing a sense of community. Includes: spread-a-quilt day; teacher exchange day; turn off the TV; Dr. Seuss day; community readers; schoolwide poets; original…

  9. 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.

  10. Evaluation of the formation environment of the carbonates in Martian meteorite ALH84001

    NASA Astrophysics Data System (ADS)

    Niles, Paul Breckenridge

    The carbonates in martian meteorite ALH84001 preserve a record of aqueous processes on Mars at 3.9 Ga, and have been suggested to contain signatures of ancient martian life. The conditions of the carbonate formation environment are critical for understanding possible evidence for life on Mars, the history of water on Mars, and the evolution of the martian atmosphere. However, the formation environment of the ALH84001 carbonates continues to be controversial. New isotopic analyses of the ALH84001 carbonates, laboratory experiments, and geochemical modeling performed in this study provide quantitative constraints on the formation environment of the ALH84001 carbonates. Microscale carbon isotope analyses of ALH84001 carbonates reveal variable d 13 C values ranging from +27[per thousand] to +64[per thousand] that are correlated with carbonate chemical compositions. Isotopic analyses of synthetic hydrothermal carbonates with chemical compositions similar to the ALH84001 carbonates do not show similar isotope compositions, correlations, or trends. Combined with earlier oxygen isotope analyses, these data are inconsistent with formation of the carbonates in previously proposed environments, and indicate that the carbonates formed in a short period of time (hours or days) from a low temperature, dynamic aqueous system. A combination of empirical and equilibrium thermodynamic modeling reveals that the precipitating fluids were Mg- and CO 2 -rich, and probably formed through low temperature (<100°C) leaching of rocks with similar compositions to ALH84001. Prior to precipitating the carbonates, the fluids must have had an Mg/Ca ratio greater than ~4 and an Fe/Ca ratio greater than ~1. Three new hypotheses are proposed that involve low temperature (<100°C), dynamic aqueous processes: the carbonates formed (1) in a sublacustrine spring environment during the mixing of two fluids derived from separate chemical and isotopic reservoirs; (2) from high pH fluids that were exposed

  11. How well is Martian ozone inferred with reflectance spectroscopy?

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1992-01-01

    The Mariner 9 UV spectrometer scanned from 2100 to 3500 Angstroms in one of its two spectral channels every 3 seconds with a spectral resolution of 15 Angstroms and an effective field-of-view of approximately 300 km(exp 2). The only gaseous absorption in the 2000 to 3000 Angstrom region was assumed to come from the Hartley band system of ozone, and therefore the amount of ozone was inferred by fitting this absorption feature with laboratory data of ozone absorption. Mars O3 as inferred from these spectra shows strong seasonal and latitudinal variation, with column abundances ranging from 0.2 microns at equatorial latitudes to 60 microns over the northern winter polar latitudes. The detectability limit of the spectrometer was approximately 3 microns. I use a radiative transfer model based on the discrete ordinate method to calculate synthetic radiance spectra. When typical amounts of dust and cloud are present, significant underestimation of O3 occurs. A factor of 3 times as much O3 is needed to generate the same spectrum for cloudy, dusty atmospheres as for a clear atmosphere. If the scattering properties of Martian clouds and dust were well known, then their appearance would not be a problem, as a model would be capable of retrieving the O3 abundance. However, these properties are not well known, which raises doubts about the effectiveness of the current UV spectroscopy technique used to measure O3. Spatial and temporal variability in temperature and water vapor have been claimed to account for the scatter of the data points. However, water vapor is a small source of odd hydrogen in the winter polar atmosphere, and may not account for most of the variability. Masking by clouds and dust may also account for some of the observed O3 variability, because the nature and opacity of the clouds and dust in the polar hood change dramatically in latitude and even on a day-to-day basis. As the maximum O3 abundance resides near the surface, spacecraft must be able to observe

  12. 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

  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. The optical depth sensor (ODS) for column dust opacity measurements and cloud detection on martian atmosphere

    NASA Astrophysics Data System (ADS)

    Toledo, D.; Rannou, P.; Pommereau, J.-P.; Foujols, T.

    2016-05-01

    A lightweight and sophisticated optical depth sensor (ODS) able to measure alternatively scattered flux at zenith and the sum of the direct flux and the scattered flux in blue and red has been developed to work in martian environment. The principal goals of ODS are to perform measurements of the daily mean dust opacity and to retrieve the altitude and optical depth of high altitude clouds at twilight, crucial parameters in the understanding of martian meteorology. The retrieval procedure of dust opacity is based on the use of radiative transfer simulations reproducing observed changes in the solar flux during the day as a function of 4 free parameters: dust opacity in blue and red, and effective radius and effective width of dust size distribution. The detection of clouds is undertaken by looking at the time variation of the color index (CI), defined as the ratio between red and blue ODS channels, at twilight. The retrieval of altitude and optical depth of clouds is carried out using a radiative transfer model in spherical geometry to simulate the CI time variation at twilight. Here the different retrieval procedures to analyze ODS signals, as well as the results obtained in different sensitivity analysis are presented and discussed.

  15. The optical depth sensor (ODS) for column dust opacity measurements and cloud detection on martian atmosphere

    NASA Astrophysics Data System (ADS)

    Toledo, D.; Rannou, P.; Pommereau, J.-P.; Foujols, T.

    2016-08-01

    A lightweight and sophisticated optical depth sensor (ODS) able to measure alternatively scattered flux at zenith and the sum of the direct flux and the scattered flux in blue and red has been developed to work in martian environment. The principal goals of ODS are to perform measurements of the daily mean dust opacity and to retrieve the altitude and optical depth of high altitude clouds at twilight, crucial parameters in the understanding of martian meteorology. The retrieval procedure of dust opacity is based on the use of radiative transfer simulations reproducing observed changes in the solar flux during the day as a function of 4 free parameters: dust opacity in blue and red, and effective radius and effective width of dust size distribution. The detection of clouds is undertaken by looking at the time variation of the color index (CI), defined as the ratio between red and blue ODS channels, at twilight. The retrieval of altitude and optical depth of clouds is carried out using a radiative transfer model in spherical geometry to simulate the CI time variation at twilight. Here the different retrieval procedures to analyze ODS signals, as well as the results obtained in different sensitivity analysis are presented and discussed.

  16. Nitrogen and Argon in ALH 84001 Revisited: Unravelling a Martian Atmospheric Component

    NASA Astrophysics Data System (ADS)

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

    1996-03-01

    We have measured nitrogen and argon released simultaneously upon combustion of two samples of ALH 84001 (A84). Both nitrogen and argon appeared to be heterogeneously distributed in the rock: one sample liberated very little gas above blank levels, whereas the second sample, selected because it contained abundant material from the "crush zones", was rich in both species. Using the ^40Ar/^14N ratio and delta ^15N of the gas liberated above 700 degrees C from this second sample, an attempt has been made to calculate the relative quantities of adsorbed terrestrial gases and trapped martian atmospheric species. Following from this, excess ^40Ar attributed to radiogenic production from potassium decay can be used to determine a K-Ar age of the sample. We calculate that ~17.5% of the total ^40Ar is indigenous to the sample. Assuming that the trapped component would have a ^40Ar/^14N ratio equivalent to that in the present-day martian atmosphere (~0.33), then there is a small excess of ^40Ar (amounting to about 1.5% of the total ^40Ar). Taking a reasonable estimate of the potassium abundance (100-200 ppm) implies that A84 has a K-Ar age of ~0.76-1.28 Gyr, which is much younger than ages determined in previous studies and using other methods.

  17. Phoenix Conductivity Probe after Extraction from Martian Soil on Sol 99

    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 Surface Stereo Imager on Phoenix took this image on the morning of Sol 99 after the probe was lifted away from the soil. This imaging served as a check of whether soil had stuck to the needles.

    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.

  18. First Day of Life

    MedlinePlus

    ... Things to Know About Zika & Pregnancy The First Day of Life KidsHealth > For Parents > The First Day ... continue What Your Baby Does on the First Day Many parents are surprised to see how alert ...

  19. 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

  20. 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