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Sample records for arabia terra mars

  1. Ancient Hydrothermal Springs in Arabia Terra, Mars

    NASA Technical Reports Server (NTRS)

    Oehler, Dorothy Z.; Allen, Carlton C.

    2008-01-01

    Hydrothermal springs are important astrobiological sites for several reasons: 1) On Earth, molecular phylogeny suggests that many of the most primitive organisms are hyperthermophiles, implying that life on this planet may have arisen in hydrothermal settings; 2) on Mars, similar settings would have supplied energy- and nutrient-rich waters in which early martian life may have evolved; 3) such regions on Mars would have constituted oases of continued habitability providing warm, liquid water to primitive life forms as the planet became colder and drier; and 4) mineralization associated with hydrothermal settings could have preserved biosignatures from those martian life forms. Accordingly, if life ever developed on Mars, then hydrothermal spring deposits would be excellent localities in which to search for morphological or chemical remnants of that life. Previous attempts to identify martian spring deposits from orbit have been general or limited by resolution of available data. However, new satellite imagery from HiRISE has a resolution of 28 cm/pixel which allows detailed analysis of geologic structure and geomorphology. Based on these new data, we report several features in Vernal Crater, Arabia Terra that we interpret as ancient hydrothermal springs.

  2. Supervolcanoes Within an Ancient Volcanic Province in Arabia Terra, Mars

    NASA Technical Reports Server (NTRS)

    Michalski, Joseph. R.; Bleacher, Jacob E.

    2014-01-01

    Several irregularly shaped craters located within Arabia Terra, Mars represent a new type of highland volcanic construct and together constitute a previously unrecognized martian igneous province. Similar to terrestrial supervolcanoes, these low-relief paterae display a range of geomorphic features related to structural collapse, effusive volcanism, and explosive eruptions. Extruded lavas contributed to the formation of enigmatic highland ridged plains in Arabia Terra. Outgassed sulfur and erupted fine-grained pyroclastics from these calderas likely fed the formation of altered, layered sedimentary rocks and fretted terrain found throughout the equatorial region. Discovery of a new type of volcanic construct in the Arabia volcanic province fundamentally changes the picture of ancient volcanism and climate evolution on Mars. Other eroded topographic basins in the ancient Martian highlands that have been dismissed as degraded impact craters should be reconsidered as possible volcanic constructs formed in an early phase of widespread, disseminated magmatism on Mars.

  3. Supervolcanoes within an ancient volcanic province in Arabia Terra, Mars.

    PubMed

    Michalski, Joseph R; Bleacher, Jacob E

    2013-10-01

    Several irregularly shaped craters located within Arabia Terra, Mars, represent a new type of highland volcanic construct and together constitute a previously unrecognized Martian igneous province. Similar to terrestrial supervolcanoes, these low-relief paterae possess a range of geomorphic features related to structural collapse, effusive volcanism and explosive eruptions. Extruded lavas contributed to the formation of enigmatic highland ridged plains in Arabia Terra. Outgassed sulphur and erupted fine-grained pyroclastics from these calderas probably fed the formation of altered, layered sedimentary rocks and fretted terrain found throughout the equatorial region. The discovery of a new type of volcanic construct in the Arabia volcanic province fundamentally changes the picture of ancient volcanism and climate evolution on Mars. Other eroded topographic basins in the ancient Martian highlands that have been dismissed as degraded impact craters should be reconsidered as possible volcanic constructs formed in an early phase of widespread, disseminated magmatism on Mars. PMID:24091975

  4. Evidence for explosive volcanism in Arabia Terra, Mars

    NASA Astrophysics Data System (ADS)

    Michalski, Joseph; Bleacher, Jacob

    2014-05-01

    Several irregularly shaped craters located within Arabia Terra, Mars, represent a new type of volcanic construct and together constitute a previously unrecognized Martian igneous province. Similar to terrestrial supervolcanoes, these low-relief paterae exhibit a range of geomorphic features related to structural collapse, effusive volcanism and explosive eruptions. They were likely active in the Late Noachian or Early Hesperian and would have affected the climate, atmospheric composition, and regional surface geology at that time. Lavas extruded from these calderas contributed to the formation of enigmatic highland ridged plains in Arabia Terra, but these volcanoes do not exhibit shield-like topographic profiles related to the sustained, localized effusive eruption of basaltic lava. We suggest that the lack of a single edifice, the large volume of collapse within an associated with the calderas, and the association of the calderas with vast deposits friable clastic deposits all indicate that these volcanoes were dominated by explosive activity. Layered, friable deposits found throughout Arabia Terra have enigmatic origins, though these materials have been suggested to represent volcanic ash. Attempts to link the locations of various friable deposits in equatorial regions to known volcanic sources have demonstrated that this hypothesis is plausible, but a link between friable deposits and known volcanic sources in this particular region (Arabia Terra) has yet to emerge. We suggest that some of the layered, friable materials were sourced from calderas in Arabia Terra. Outgassed sulphur and water from these calderas would have contributed to the alteration of layered clastic materials in Arabia Terra, and perhaps throughout the equatorial region.

  5. A case for ancient springs in Arabia Terra, Mars.

    PubMed

    Allen, Carlton C; Oehler, Dorothy Z

    2008-12-01

    Based on new image data from the High Resolution Imaging Science Experiment (HiRISE) on Mars Reconnaissance Orbiter (MRO), a case can be made that several structures in Vernal Crater, Arabia Terra are ancient springs. This interpretation is based on comprehensive geomorphologic analysis coupled with assessment of multiple hypotheses. The structures identified extend across several kilometers and are exceptional in that nothing with their detail and scale has been reported from Mars. The deposits are associated with an extensive fracture system that may have facilitated upward flow of warm fluids. Several additional spring-like features occur in Vernal Crater, and it is possible that these are part of a major province of spring activity. Since springs are environments where life could have evolved on Mars, where that life could have found refuge as the climate became colder and drier, and where signatures of that life may be preserved, Vernal Crater may be a site of major astrobiological importance. PMID:19093802

  6. Prospecting for Methane in Arabia Terra, Mars - First Results

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Oehler, Dotoyhy Z.; Venechuk, Elizabeth M.

    2006-01-01

    Methane has been measured in the Martian atmosphere at concentrations of approx. 10 ppb. Since the photochemical lifetime of this gas is approx. 300 years, it is likely that methane is currently being released from the surface. Possible sources for the methane include 1) hydrothermal activity, 2) serpentinization of basalts and other water-rock interactions, 3) thermal maturation of sedimentary organic matter, and 4) metabolism of living bacteria. Any such discovery would revolutionize our understanding of Mars. Longitudinal variations in methane concentration, as measured by the Planetary Fourier Spectrometer (PFS) on Mars Express, show the highest values over Arabia Terra, Elysium Planum, and Arcadia-Memnonia, suggesting localized areas of methane release. We are using orbital data and methodologies derived from petroleum exploration in an attempt to locate these release points.

  7. Hints at diapirism in Arabia Terra bulged craters (Mars)

    NASA Astrophysics Data System (ADS)

    Pozzobon, R.; Massironi, M.; Rossi, A. P.; Sauro, F.; Carli, C.; Marinangeli, L.; Cremonese, G.

    2015-10-01

    Impact craters within Arabia Terra region,on Mars,display a large central bulge, sometimes showing a well-preserved stratification (light albedo layered deposits). In craters like Crommelin or an unnamed crater (that is numbered 12000088) located a few hundreds kilometers on the East some unusual landforms and structures among the layered deposits were observed. In particular, on Crommelin's bulge and its surroundings we found fold systems with axis parallel to the bulge perimeter. The fold sets are typical compressional structure often associated to diapiric rise on Earth[1]. In addition on top of 12000088 crater's bulge the evidence of sulfate signatures was detected as well as the presence of small bowl-shaped depressions. Several fluid-carved channels that depart radially from the bulge are cut by a ring of normal faults,thus suggesting a collapse of the bulge summit. Thus, on the basis of the previous observations it is possible to hypothesize that diapiric rise could have been responsible for central bulging both on Crommelin and 12000088 craters and likely on other bulged craters on Arabia Terra.

  8. Hints at diapirism in Arabia Terra craters, Mars

    NASA Astrophysics Data System (ADS)

    Pozzobon, Riccardo; Pio Rossi, Angelo; Massironi, Matteo; Mazzarini, Francesco; Pondrelli, Monica; Marinangeli, Lucia; Unnithan, Vikram

    2014-05-01

    Arabia Terra is a region of Mars located at the boundary between the southern highlands and the northern lowlands and classically dominated by heavily cratered terrain. Unlike the rest of the topographic dichotomy on the planet, in Arabia Terra the elevation transition is very gentle, falling of 4 km over a distance of 2500 km (average slope = 0.0016°). Most of the impact craters within the region display a central bulge, bearing a well preserved stratification and a wide range of smaller morphologies like pitted cones, mounds and knobs (Franchi et al. 2013). Images acquired by HiRISE and CTX cameras on board MRO provided a comprehensive dataset in which also these small features can be easily recognized. These are tens of meters of diameter and tens of meters high, and many of them show an apical orifice. They are interpreted to have worked as pathways for subsurface fluid flow (e.g. Pondrelli et al., 2011; Rossi et al., 2008). Indeed an active underground fluid flow activity in Arabia Terra It has been recently hypothesized (e.g. Andrews-Hanna et al, 2011) , being crater central bulges a place of sulfate precipitation, due to local water table emergence (e.g. Franchi et al., 2013). To date, there is no clear explanation for occurrence of central bulges surrounded by prominent depressions in Arabia craters. In addition, in Firsoff and Crommelin craters it is possible to recognize folds and outward dipping strata on the central bulges and their surroundings. Interestingly, a few craters with a prominent bulged floor elsewhere in Arabia Terra do not display stratification and are not explainable as impact related structures as their expected pristine central peak derived by hydrocode modelling is ~2km lower and one third the diameter than the actual topography (Pozzobon et al., 2013). All these evidences are not consistent with a typical lacustrine stratigraphic environment, whether interested by sulfate precipitation or not, and suggest active deformation after or

  9. Arabia Terra

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    This image shows deposits in a crater located in Arabia Terra. Arabia is generally dust covered and dark streaks or dust avalanches are present in the crater walls. The dominant geologic process acting in this crater interior is wind erosion. The central crater deposits are eroded to form yardangs, or linear wind-sculpted hills that resemble an inverted boat hull. Deflation and abrasion are capable of eroding rock structures that are aligned parallel to wind direction. In the lower right hand side of the crater, a dark deposit has formed barchan dunes. These crescent shaped dunes have 'horns' that point downwind indicating general northwest to southeast wind direction. These dark sands probably played a role in the erosion and formation of the yardangs.

    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.

  10. Amazonian thermokarst in Danielson crater, Arabia Terra region, Mars

    NASA Astrophysics Data System (ADS)

    Baioni, Davide; Murana, Alessio; Tramontana, Mario

    2014-12-01

    This paper describe the possible ice-related landforms observed within Danielson crater which is centered at about 8°N and 353°E, in the region of southwestern Arabia Terra about 800 km south of Becquerel crater. A morphological survey of the study area through an analysis of the available Mars images was performed. The features of the landforms were investigated through an integrated analysis of Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) data. Landforms interpreted as due to thermokarst processes, resembling similarly ice-related landforms found both in the cold-climate non-glacial regions of Earth, and putatively in other areas of Mars, was observed. These landforms are attributed to the presence of ground ice/ice-melting processes reflect significant climatic changes and different climatic conditions than those existing now. Moreover, they appear to display young erosional age, suggesting that are probably young, probably of Amazonian age.

  11. Fresh Shallow Valleys (FSVs) in Northern Arabia Terra, Mars

    NASA Astrophysics Data System (ADS)

    Wilson, S. A.; Howard, A. D.; Moore, J. M.

    2014-12-01

    Fresh Shallow Valleys (FSVs) on Mars are part of a growing inventory of post-Noachian landforms that may be related to late, widespread aqueous activity that occurred during a period once thought to be less favorable for precipitation and runoff. Constraining the source, magnitude, timing and duration of FSVs will provide insight into the mechanism and extent of fluvial activity on Mars and the geologic and climatic environments in which they formed. Unlike the older Noachian-Hesperian valleys that are characterized by integrated, dissected and degraded networks that cover large spatial extents, FSVs are typically narrow, short or discontinuous valleys with low drainage densities. They are generally incised no more than a few decameters, slightly degraded at multi-meter scales, and cluster in the mid-latitudes (35-50° in both hemispheres). A high concentration of FSVs occurs in Northern Arabia Terra (~33°N, 8°E), a Noachian-aged landscape characterized by broad, irregular depressions. Many of the FSVs in this region are 150+ km long and some appear to cross depressions that were likely filled with ice or water at the time of formation. Examples of broad, flat floored FSVs with incised channels could either indicate a complex history of a single flow event or multiple flow events. The occurrence of "pollywogs," fairly fresh, small (typically 2-10 km in diameter) craters with a single channel extending from the rim outward, implies overflow of the crater, the presence of a deep lake and the involvement of artesian groundwater flow. Roughly 25% of the FSVs in our northern Arabia Terra study region occur on relatively fresh crater ejecta, which may be related to formation age, topography, surface materials and (or) substrate. Ejecta with dense concentrations of FSVs average 25.5 km in diameter, have more degraded crater interiors, and well developed petal-like ejecta. Ejecta with sparse or no FSVs have radial ejecta with less distinct petals and are associated with

  12. Possible ancient giant basin and related water enrichment in the Arabia Terra province, Mars

    USGS Publications Warehouse

    Dohm, J.M.; Barlow, N.G.; Anderson, R.C.; Williams, J.-P.; Miyamoto, H.; Ferris, J.C.; Strom, R.G.; Taylor, G.J.; Fairen, A.G.; Baker, V.R.; Boynton, W.V.; Keller, J.M.; Kerry, K.; Janes, D.; Rodriguez, J.A.P.; Hare, T.M.

    2007-01-01

    A circular albedo feature in the Arabia Terra province was first hypothesized as an ancient impact basin using Viking-era information. To test this unpublished hypothesis, we have analyzed the Viking era-information together with layers of new data derived from the Mars Global Surveyor (MGS) and Mars Odyssey (MO) missions. Our analysis indicates that Arabia Terra is an ancient geologic province of Mars with many distinct characteristics, including predominantly Noachian materials, a unique part of the highland-lowland boundary, a prominent paleotectonic history, the largest region of fretted terrain on the planet, outflow channels with no obvious origins, extensive exposures of eroded layered sedimentary deposits, and notable structural, albedo, thermal inertia, gravity, magnetic, and elemental signatures. The province also is marked by special impact crater morphologies, which suggest a persistent volatile-rich substrate. No one characteristic provides definitive answers to the dominant event(s) that shaped this unique province. Collectively the characteristics reported here support the following hypothesized sequence of events in Arabia Terra: (1) an enormous basin, possibly of impact origin, formed early in martian history when the magnetic dynamo was active and the lithosphere was relatively thin, (2) sediments and other materials were deposited in the basin during high erosion rates while maintaining isostatic equilibrium, (3) sediments became water enriched during the Noachian Period, and (4) basin materials were uplifted in response to the growth of the Tharsis Bulge, resulting in differential erosion exposing ancient stratigraphic sequences. Parts of the ancient basin remain water-enriched to the present day. ?? 2007 Elsevier Inc. All rights reserved.

  13. Active aeolian processes on Mars: A regional study in Arabia and Meridiani Terrae

    USGS Publications Warehouse

    Silvestro, S.; Vaz, D.A.; Fenton, L.K.; Geissler, P.E.

    2011-01-01

    We present evidence of widespread aeolian activity in the Arabia Terra/Meridiani region (Mars), where different kinds of aeolian modifications have been detected and classified. Passing from the regional to the local scale, we describe one particular dune field in Meridiani Planum, where two ripple populations are distinguished by means of different migration rates. Moreover, a consistent change in the ripple pattern is accompanied by significant dune advancement (between 0.4-1 meter in one Martian year) that is locally triggered by large avalanche features. This suggests that dune advancement may be common throughout the Martian tropics. ?? 2011 by the American Geophysical Union.

  14. A new perspective on ancient martian volcanism: evidence for supervolcanoes in Arabia Terra, Mars

    NASA Astrophysics Data System (ADS)

    Michalski, J. R.; Bleacher, J. E.; Wright, S. P.

    2013-12-01

    While many Hesperian and Amazonian volcanic constructs on Mars are easily recognizable from their shield morphologies, significantly less is known about ancient (Noachian and earliest Hesperian) martian volcanism. Yet, heat flow in the martian crust was higher in the Noachian and therefore the planet was likely more magmatically active [1]. It is possible that Noachian volcanic constructs have largely escaped detection because higher erosion rates on ancient Mars destroyed geomorphological evidence for their existence. However, another possibility exists: some ancient volcanoes on Mars might have been of a fundamentally different character compared to well known, younger shield volcanoes because of an explosive nature of the more ancient ones. We present evidence for ancient supervolcanoes within the Arabia Terra region of Mars. Several large (~20-70 km-diameter) craters within Arabia Terra display little or no evidence for impact origins and exhibit various degrees of evidence for volcanism. These structures, which we term 'plains style caldera complexes,' show no evidence for preserved ejecta, raised rims, inverted stratigraphy, or central peaks that could be attributed to meteor impact-related processes. While it is possible that any evidence for impact origins was removed by erosion, we consider this unlikely because crater degradation generally leads to lower depth-diameter ratios [2] and these structures have high depth-diameter ratios, comparable to values for unmodified craters [3]. In fact, erosion has been low enough to preserve various pieces of evidence for volcanism associated with the structures, such as association with ridged plains lavas, possible vent structures, evidence for lava lakes in some cases, and association with sagging crust possibly related to magma migration or withdrawal. Taken together, these structures represent a newly recognized type of volcanism on Mars dominated by explosive volcanism and structural collapse. They occur within

  15. Mars Eolian Geology at Airphoto Scales: The Large Wind Streaks of Western Arabia Terra

    NASA Technical Reports Server (NTRS)

    Edgett, Kenneth S.

    2001-01-01

    More than 27,000 pictures at aerial photograph scales (1.5-12 m/pixel) have been acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) since September 1997. The pictures are valuable for testing hypotheses about geologic history and processes of Mars. Of particular interest are eolian features connected to surface albedo patterns. This work is focused on low-albedo wind streaks, some over 100 km long, in western Arabia Terra. Each streak is widest where it originates at an impact crater (typically 25-150 km diameter). The streaks taper downwind. Within the associated craters there is a lower-albedo surface that, in nearly all observed cases, includes barchan dunes indicative of transport in the same direction as the wind streaks. Upwind of the dunes there is usually an outcrop of layered material that might have served as a source for dune sand. MOC images show that the west Arabia streaks consist of a smooth-surfaced, multiple-meters-thick, mantle (smooth at 1.5 m/pixel) that appears to be superposed on local surfaces. No dunes are present, indicating that down-streak transport of sediment via saltation and traction have not occurred. Two models might explain the observed properties: (1) the streaks consist of dark silt- and clay-sized grains deflated from the adjacent crater interiors and deposited from suspension or (2) they are remnants (protected in the lee of impact crater rims) of a formerly much larger, regional covering of low albedo, smooth-surfaced mantle. The latter hypothesis is based on observation of low albedo mantled surfaces occurring south of west Arabia in Terra Meridiani. For reasons yet unknown, a large fraction of the martian equatorial regions are covered by low albedo, mesa-forming material that lies unconformably atop eroded layered and cratered terrain. Both hypotheses are being explored via continued selective targeting of new MOC images as well as analyses of the new data.

  16. Age dates of valley network drainage basins and subbasins within Sabae and Arabia Terrae, Mars

    NASA Astrophysics Data System (ADS)

    Bouley, Sylvain; Craddock, Robert A.

    2014-06-01

    The precise timing of valley network drainage basin formation is critical to understanding the history of water and climate on Mars. To determine whether there are any variations in ages within separate drainage basins and subbasins that may reflect local or regional variations in climate or resetting from resurfacing (e.g., impact ejecta or lava flows), we dated 27 basins and subbasins in Sabaea and Arabia Terrae. The age-dating basin technique we employed allowed sufficient precision to give accurate ages and shows that fluvial activity within the basins and subbasins ceased at approximately the same time around the Early Hesperian/Late Hesperian transition. Our results support the hypothesis that valley networks formed during a unique "fluvial optimum" that may have shut off gradually because of a global climate change that affected all areas simultaneously on Mars.

  17. Layered Deposits of Arabia Terra and Meridiani Planum: Keys to the Habitability of Ancient Mars

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Oehler, Dorothy Z.; Paris, Kristen N.; Venechuk, Elizabeth M.

    2006-01-01

    Understanding the habitability of ancient Mars is a key goal in the exploration of that planet. Evidence for conditions favorable to early life must be sought in ancient sedimentary rocks, such as those of Arabia Terra and Meridiani Planum. Arabia Terra, the northernmost extension of the ancient highlands, is dominated by cratered plains and minor ridged units. These plains extend south into the adjacent Meridiani Planum. The Opportunity rover landed in northern Meridiani, close to the border with Arabia. High resolution MOC images reveal extensive layered sequences across much of the Arabia and Meridiani region. These layers have been interpreted as eroded remnants of sedimentary rock deposits (Edgett, 2005). The layered sequences are concentrated in the SW quadrant of Arabia and in northern Meridiani. Preliminary mapping by Edgett (2005) distinguished four large scale layered sequences in the Arabia and Meridiani region. These have dimensions of hundreds to more than 1,000 km. MOLA altimetry shows that each of the sequences can attain a thickness of 200 to 400 m, with a total thickness greater than 1 km. The sequences are generally flat lying, with regional slopes of a few degrees. Much finer layering is evident within a number of craters. The plains and ridged units of the Arabia and Meridiani region were originally mapped as Noachian based on crater statistics, particularly the number of large craters (Scott and Carr, 1978). The layered sequences in the current study postdate many, but not all, of these large craters. The layered sequences have partially or totally filled a number of craters with diameters ranging from 20 to over 50 km. The topmost layered sequence, as well as the lower two sequences, have intermediate thermal inertia, as derived from THEMIS, indicative of moderate induration. The TES spectra from the lower sequences include features indicative of basalt. Some areas of the topmost sequence, which includes the Opportunity landing site, have TES

  18. Testing Formation Theories of NW Arabia Terra, Mars: New Clues from Old Craters

    NASA Astrophysics Data System (ADS)

    Robbins, S. J.; Hynek, B. M.

    2008-03-01

    Northwest Arabia Terra has topography and crater populations indicating a unique history. We directly tested two proposed formation mechanisms. Crater size-frequency and d/D ratios suggest neither scenario is easily reconcilable with the new datasets.

  19. Subsidence and Collapse Activity in Arabia Terra, Mars: Which Link with Magmatic Activity?

    NASA Astrophysics Data System (ADS)

    Mangold, N.; Howard, A. D.

    2014-12-01

    Collapsed terrains have been observed using Viking images in the northern part of Arabia Terra from Ismenius Lacus to Deuteronilus Mensae. Recent interpretations of some of these depressions as explosive volcanoes (Michalski and Bleacher, 2013) have renewed the interest for this region. However, recent observations also show the discovery in this region of a series of outflow channels named Okavango Valles (Mangold and Howard, 2013). These channels formed in the Hesperian through catastrophic flows having deposited sediments as deltas in ephemeral lakes. The source area of these channels takes place in a region of widespread depressions and local collapse pits. A continuum of landforms exists from broad depressions (~100 km in length and 100s m in depth) and sharper collapse structures (<100 km in diameter). Given the link between these depressions and the presence of outflow channels, we interpret the collapse structures as resulting from a specific lithology with volatile-rich sediments (or megaregolith) buried at depth. Collapse may be due either to the melting of subsurface ice, or subsurface flows triggered by a change in the groundwater table, or the (less likely) dissolution of buried chemical sediments. Magmatic activity is not excluded: a regionally enhanced thermal flux during the Hesperian could have triggered ground ice melting, and could have initiated subsidence subsequently, but explosive volcanism at the surface is not necessary to explain the presence of large collapsed terrains. Michalski, J. and J. Bleacher, 2013. Supervolcanoes within an ancient volcanic province in Arabia Terra, Mars, Nature, doi:10.1038/nature12482 Mangold N., and A. D. Howard, 2013. Outflow channels with deltaic deposits in Ismenius Lacus, Mars, Icarus, doi.org/10.1016/j.icarus.2013.05.040

  20. Fluvial Interpretation of Ridged Units, Northern Sinus Meridiani/Southwest Arabia Terra, Mars

    NASA Astrophysics Data System (ADS)

    Wilkinson, J.; Allen, C. C.; Oehler, D. Z.

    2007-12-01

    THEMIS, MOC, and HiRISE imagery shows features at various scales that suggest fluvial emplacement of the ridge-forming rock units exposed in northern Sinus Meridiani and southwestern Arabia Terra. The study area -- 10 N to 2 S latitude and 10 W to 8 E longitude -- spans the interface from the southern highlands to the northern plains. Numerous, linear ridges of varying width, orientation and sinuosity (mainly lower sinuosity) are suggestive of fluvial channels. Sets of features can be interpreted as braided channel reaches. Cross-cutting relationships, a common feature of channels on terrestrial fluvial plains, are ubiquitous. Many sinuous features appear as twinned parallel lines, suggesting preferential cementing of coarser channel-bank sediments. A few examples exist of features that can be interpreted as scroll bars and channel augmentation in locally narrow reaches. Layering and internal discontinuities of the Meridiani rocks are consistent with a fluvial interpretation. The regional setting of study-area units accords closely with many terrestrial basins which are occupied by fluvially emplaced sediment bodies known as megafans. Contiguous megafan surfaces (characterized by numerous channel traces, of varied orientation) cover large areas -- 1.25 million sq. km. in S. America -- with radii of hundreds of km. Megafans characteristically lie at the foot of a backing highland, from which rivers supply sediment. The ridged units on Mars lie at the foot of the southern highlands from which numerous river valleys have drained towards Meridiani Planum/southwest Arabia Terra. Further, the present regional slope is apparently away from the highlands, with downslope dimensions of hundreds of km. The low slopes of the northern Meridiani units mirror the typically low regional slopes of terrestrial megafans. Low slopes are conducive to the development of water bodies, which are numerous on some terrestrial megafans. The lacustrine model for the formation of the hematite

  1. Layered Sediments, Rampart Craters, and Potential Fluvio-Lacustrine Activity in S.W. Arabia Terra, Mars: Support for a History of Aqueous Conditions

    NASA Technical Reports Server (NTRS)

    Oehler, D. Z.; Allen, C. C.; Venechuk, E. M.; Paris, K. N.

    2007-01-01

    Arabia Terra is a unique area on Mars in that it is the only major, equatorial region characterized by high abundances of near-surface water (as measured by gamma ray and neutron spectroscopy). Vernal Crater is a 55 km-diameter structure in southwest Arabia Terra, centered at 6 N, 355.5 E. The crater includes layered sediments, potential remnants of fluvio-lacustrine activity, and indications of aeolian processes. Regional considerations, along with new THEMIS and MOC data, are being assessed to gain insight into the significance of the geomorphic units within Vernal Crater and the geologic history of SW Arabia Terra.

  2. Age-Dating Drainage Basins in Sabae and Arabia Terrae, Mars

    NASA Astrophysics Data System (ADS)

    Bouley, S.; Craddock, R. A.

    2013-12-01

    The precise timing of drainage basins is critical to understanding the climate history on Mars. One of the obvious problems with age-dating valley networks is the fact that they are small, linear features that are easily destroyed by large impact craters, thus counting craters on valley networks themselves is difficult at best. We proposed a new global study dating 27 drainage basins and subbasins in Sabaea and Arabia Terrae with the basin age-dating technique. Valley networks are contained within drainage basins, which is defined as the area that contributes water to a particular channel or set of channels . For our study, we used THEMIS (Thermal Emission Imaging System) visible images with a spatial resolution of 100 m/pixel which allow us to count craters with diameter of 1 km and larger. A digital elevation model (DEM) using 1/128 gridded Mars Orbiter Laser Altimeter (MOLA) helped us to extract the 26 basins and sub-basins drainage divides From these measurements, our study shows: (1) that all the drainages basins of a large region seem to cease their main fluvial activity at the same time at the end of the Early Hesperian epoch (~3.54 Gyr); (2) that the basin technique is the most reliable technique to do global age-dating; and (3) that there is a possible correlation between the degradation rate and the elevation. Our conclusions suggest that the main fluvial activity ceased because of a global climate change. We suppose that most of valley networks on Mars we observed today formed during the Early Hesperian and post-dated the early and late Noachian topographic features.

  3. Aram Dorsum, Candidate ExoMars Rover Landing Site: a Noachian Inverted Fluvial Channel System in Arabia Terra Mars

    NASA Astrophysics Data System (ADS)

    Balme, Matthew; Grindrod, Peter; Sefton-Nash, Elliot; Davis, Joel; Gupta, Sanjeev; Fawdon, Peter

    2016-04-01

    Much of Mars' Noachian-aged southern highlands is dissected by systems of fluvial channels and valleys > 3.7 Ga in age. Arabia Terra, lying between the southern highlands and the northern lowlands, is similarly ancient, yet apparently has few valley networks. This regional lack of valley networks only matches Noachian precipitation predictions from climate models if the Noachian climate was dry and cold [1]. In this scenario, highlands dissection was caused by transient flows of meltwater from large, regionally restricted ice-bodies. However, new results [2,3] show that Arabia Terra is not as poorly dissected as previously thought, and in fact there are extensive networks of inverted channel systems. Here, we describe an example of such a system - Aram Dorsum - which has been studied extensively as an ExoMars Rover candidate landing site. Aram Dorsum is an ~100 km long, 1-2 km wide, branching, flat-topped ridge system, in western Arabia Terra. We have mapped the system using CTX images, DEMs and other data. We interpret the ridge system to be fluvial in origin, preserved in positive relief due to infill and differential erosion; this working hypothesis is used as a conceptual framework for the study. Aram Dorsum is a branching, multi-level, contributory network, set in surrounding floodplains-like material. This demonstrates that it was a relatively long-lived, aggradational fluvial system, rather than an erosional outflow or bedrock-carved fluvial channel. Interestingly, the system shows little evidence for unconfined lateral channel migration, so there must have been significant bank stability. Aram Dorsum was therefore probably once a sizable river and, as just one example of many similar systems, is an exemplar for the middle part of a regional sediment transport system that could have extended from the southern highlands to the northern lowlands. Like Aram Dorsum, many of these other recently-recognized fluvial systems have an origin more consistent with

  4. Geometry, stratigraphy and evidences for fluid expulsion within Crommelin crater deposits, Arabia Terra, Mars

    NASA Astrophysics Data System (ADS)

    Franchi, F.; Rossi, A. P.; Pondrelli, M.; Cavalazzi, B.

    2014-03-01

    Conical mounds and furrows are widely interpreted as the morphological evidences of fluids expulsion on the martian surface. In the Crommelin crater (equatorial Arabia Terra) furrows and conical mounds are exhumed within light-toned equatorial layered deposits (ELDs). Aim of this paper is to describe these landforms and discuss their potential relations with water upwelling in Crommelin area. A comparative study of some of the morphologies hosted in the Crommelin area deposits have been performed by using multiple datasets (CTX, HRSC, MOLA, HiRISE). Then examples of spring and conical mounds on Earth was examined for comparison with analog structures on Mars. In this work thickness and geometries of the crater filling sediment packages have been calculated. Stratigraphic contacts and relations have been also reported in Crommelin area revised geological map, and mound clusters, potentially fluid-related morphologies, from Crommelin, Firsoff and Southern crater have been detailed. The morphometric and morphological analyses revealed that mounds and other structures occur where the ELDs are thicker and crudely layered. In addition, orthorectified imagery and high-resolution topography indicated the presence of conical mounds within the upper portion of ELDs near the craters rims. Mounds show apical holes and are linked to elongated structures resembling veins and dikes. Elongated structures (furrows) and concentric strata pattern that we refer to as ridge-and-through, were described inside to Crommelin crater. MOLA-based DEMs revealed that these morphologies developed within a flat topography and are inconsistent with gravitative processes. The results suggest that the inferred sediments package was likely part of an extensive zone of groundwater upwelling. This long-wavelength flow controlled water and sediments supply into the study area, probably during a major climate shift. Fluid expulsion processes were recognized as a relevant process in the formation of these

  5. Low Albedo Surfaces and Eolian Sediment: Mars Orbiter Camera Views of Western Arabia Terra Craters and Wind Streaks

    NASA Technical Reports Server (NTRS)

    Edgett, Kenneth S.

    2001-01-01

    High spatial resolution (1.5 to 12 m/pixel) Mars Global Surveyor Mars Orbiter Camera images obtained September 1997 through June 2001 indicate that the large, dark wind streaks of western Arabia Terra each originate at a barchan dune field on a crater floor. The streaks consist of a relatively thin coating of sediment deflated from the dune fields and their vicinity. This sediment drapes a previous mantle that more thickly covers nearly all of western Arabia Terra. No dunes or eolian bedforms are found within the dark wind streaks, nor do any of the intracrater dunes climb up crater walls to provide sand to the wind streaks. The relations between dunes, wind streak, and subjacent terrain imply that dark-toned grains finer than those which comprise the dunes are lifted into suspension and carried out of the craters to be deposited on the adjacent terrain. Such grains are most likely in the silt size range (3.9-62.5 micrometers). The streaks change in terms of extent, relative albedo, and surface pattern over periods measured in years, but very little evidence for recent eolian activity (dust plumes, storms, dune movement) has been observed.

  6. Sedimentary Rocks and Methane - Southwest Arabia Terra

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Oehler, Dorothy Z.; Venechuk, Elizabeth M.

    2006-01-01

    We propose to land the Mars Science Laboratory in southwest Arabia Terra to study two key aspects of martian history the extensive record of sedimentary rocks and the continuing release of methane. The results of this exploration will directly address the MSL Scientific Objectives regarding biological potential, geology and geochemistry, and past habitability.

  7. Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III; Crown, David A.

    2009-01-01

    Geologic mapping studies at the 1:1M-scale are being used to assess geologic materials and processes that shape the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary may provide constraints on: 1) origin of the dichotomy boundary, 2) paleo-environments and climate conditions, and 3) various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The results of this work will include two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

  8. Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars: Introductory Report

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III; Crown, David A.

    2008-01-01

    Geologic mapping studies at the 1:1M-scale will be used to characterize geologic processes that have shaped the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary will provide the ability to: 1) further test original dichotomy formation hypotheses, 2) constrain ancient paleoenvironments and climate conditions, and 3) evaluate various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The result will be two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

  9. The sedimentology and dynamics of crater-affiliated wind streaks in western Arabia Terra, Mars and Patagonia, Argentina

    USGS Publications Warehouse

    Rodriguez, J.A.P.; Tanaka, K.L.; Yamamoto, A.; Berman, D.C.; Zimbelman, J.R.; Kargel, J.S.; Sasaki, S.; Jinguo, Y.; Miyamoto, H.

    2010-01-01

    Wind streaks comprise recent aeolian deposits that have been extensively documented on Venus, Earth and Mars. Martian wind streaks are among the most abundant surface features on the planet and commonly extend from the downwind margins of impact craters. Previous studies of wind streaks emerging from crater interior deposits suggested that the mode of emplacement was primarily related to the deposition of silt-sized particles as these settled from plumes. We have performed geologic investigations of two wind streaks clusters; one situated in western Arabia Terra, a region in the northern hemisphere of Mars, and another in an analogous terrestrial site located in southern Patagonia, Argentina, where occurrences of wind streaks emanate from playas within maar craters. In both these regions we have identified bedforms in sedimentary deposits on crater floors, along wind-facing interior crater margins, and along wind streaks. These observations indicate that these deposits contain sand-sized particles and that sediment migration has occurred via saltation from crater interior deposits to wind streaks. In Arabia Terra and in Patagonia wind streaks initiate from crater floors that contain lithic and evaporitic sedimentary deposits, suggesting that the composition of wind streak source materials has played an important role in development. Spatial and topographic analyses suggest that regional clustering of wind streaks in the studied regions directly correlates to the areal density of craters with interior deposits, the degree of proximity of these deposits, and the craters' rim-to-floor depths. In addition, some (but not all) wind streaks within the studied clusters have propagated at comparable yearly (Earth years) rates. Extensive saltation is inferred to have been involved in its propagation based on the studied terrestrial wind streak that shows ripples and dunes on its surface and the Martian counterpart changes orientation toward the downslope direction where it

  10. Fresh Shallow Valleys in Northern Arabia Terra: Evidence for a Late, Widespread Period of Aqueous Activity on Mars

    NASA Astrophysics Data System (ADS)

    Wilson, S. A.; Howard, A. D.; Moore, J. M.; Grant, J. A., III

    2015-12-01

    Concentrations of fresh shallow valleys (FSVs) on Mars occur between ~30-45° in both hemispheres as well as near the equator (e.g., Gale crater and vicinity). FSVs in the northern hemisphere occur along the dichotomy boundary, with the highest concentration in northern Arabia Terra from 35-40°N between 0-20ºE. In this region, FSVs developed both on and away from ejecta of relatively fresh craters, making the direct association between impact processes and formation less likely. Crater statistics and cross-cutting relationships indicate the formation of FSVs terminated prior to about 1.4 Ga, suggesting they may be contemporaneous with alluvial fan and delta formation in the equatorial and mid-latitudes. Many FSV systems are 150+ km long, and in several cases appear to cross depressions that were likely filled with ice or water during FSV formation. Most FSV systems could have formed from a single episode of erosion but incision of the main channel in some locations may imply episodic formation. One long valley system in N. Arabia Terra with an incised channel (100 m wide, up to 10 m deep) yields formative discharges in the range of 100-200 m3/s assuming sand sized particles and a flow depth of 0.25 m, consistent with formation via snowmelt. The grain size is unknown, therefore discharges could range from 10s m3/s for active transport of fine sand to 1000 m3/s for gravel sized grains. Approximately 25 small craters (diameters ranging from ~2-10 km) have single channels extending outward from their rim, implying overflow of the crater and the possible presence of a deep lake. Widespread occurrence of FSVs, their similar morphology, and modest state of degradation is consistent with most forming during one or more global intervals of favorable climate, likely through snowmelt from surface or sub-ice flows during the Hesperian.

  11. Equatorial Layered Deposits in Arabia Terra, Mars: Facies and Process Variability

    NASA Astrophysics Data System (ADS)

    Pondrelli, M.; Rossi, A.; van Gasselt, S.; Le Deit, L.; Glamoclija, M.; Cavalazzi, B.; Franchi, F.; Fueten, F.; Hauber, E.; Zegers, T.

    2012-12-01

    Genetic mechanisms proposed to explain Equatorial Layered Deposits (ELDs) formation include subglacial volcanism, aeolian/airfall, lacustrine, lacustrine/volcanic and spring-fed deposition. ELDs have been frequently shown to consist of sulfates (e.g. Gendrin et al., 2005) that might form as a response to evaporation in a playa environment (Hoefen et al., 2003) or during spring precipitation (e.g. Allen and Oehler, 2008; Rossi et al., 2008). The importance of groundwater-dominated hydrological systems was proposed to explain the formation of light-toned deposits in Meridiani Planum and Arabia Terra (e.g. Andrews-Hanna et al. 2007). Additionally, fluid expulsion processes have been invoked to explain the formation of mounds within the light-toned deposits in Arabia Terra (Allen and Oehler, 2008; Rossi et al., 2008; Pondrelli et al., 2011). Potential for habitable conditions of both playa and spring-related settings (Cavalazzi et al., 2007; Glamoclija et al., 2011) coupled with the high preservation potential within sulfates (Panieri et al., 2010), make these deposits a good candidate to understand the potential past habitability of the planet. In order to investigate ELDs genesis, an area in the vicinity of Firsoff crater, where ELDs are present within and outside the craters, was selected for geological mapping and analysis of the landforms and their association using the available dataset, including CRISM in order to infer ELDs composition. Within Firsoff crater, ELDs form a bulge that can be estimated to be at least a few hundred meters thick, while, outside the craters, ELDs form flat-lying deposits. Although heavily eroded by wind and carved by yardangs, several morphologies within the ELDs in the craters seem to be depositional, which would exclude that the entire Firsoff basin had been originally filled by ELDs. Within craters, ELDs consist of roughly meter thick layers draping and onlapping the substratum. They appear affected by polygonal patterns with no

  12. A Sedimentary Platform in Margaritifer Sinus, Meridiani Terra, and Arabia?

    NASA Technical Reports Server (NTRS)

    Howard, A. D.; Moore, J. M.; Irwin, R. P., III; Craddock, R. A.

    2005-01-01

    The Margaritifer-Meridiani-Arabia highlands-lowlands (H-L) transition has long been recognized as the most fluvially dissected region of Mars. However, the geomorphic evolution of this region remains enigmatic, particularly the origin of the layered deposits of Meridiani Terra and Arabia. We suggest that a portion of this regional slope served as a fluvial depositional platform during the late Noachian.

  13. Thinking Like a Wildcatter: Prospecting for Methane in Arabia Terra, Mars

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Oehler, D. Z.

    2005-01-01

    Methane has been detected in the martian atmosphere at a concentration of approximately 10 ppb. The lifetime of such methane against decomposition by solar radiation is approximately 300 years, strongly suggesting that methane is currently being released to the atmosphere. By analogy to Earth, possible methane sources on Mars include active volcanism, hot springs, frozen methane clathrates, thermally-matured sedimentary organic matter, and extant microbial metabolism. The discovery of any one of these sources would revolutionize our understanding of Mars.

  14. Candidate Landing Site for the Mars Science Laboratory: Vernal Crater, S.W. ARabia Terra

    NASA Technical Reports Server (NTRS)

    Paris, K. N.; Allen, C. C.; Oehler, D. Z.

    2007-01-01

    In the fall of 2009, the Mars Science Laboratory (MSL) will be launched to Mars. The purpose of this mission is to assess biologic potential and geology and to investigate planetary processes of relevance to past habitability. MSL will be able to provide visual, chemical, radiation, and environmental data with its suite of instruments [1]. In order to be selected for the MSL landing site, certain engineering requirements must be met [1] and the area should contain geologic features suggestive of past habitability, so that the overriding science goal of the mission will be attained. There are a total of 33 proposed landing sites as of the first MSL Landing Site Workshop held in Pasadena, CA from May 31st to June 2nd, 2006 [1]. There will be an opportunity to gather high resolution visual and hyperspectral data on all proposed landing sites from the now-orbiting Mars Reconnaissance Orbiter (MRO) which entered martian orbit and began its main science phase in November of 2006 [2]. The data being gathered are from: the high resolution imaging science experiment (HiRISE), the context (CTX) camera and the compact reconnaissance imaging spectrometer (CRISM) onboard the spacecraft. The footprints of these instruments are centered on a single point, and each proposer must submit these coordinates, along with the coordinates of the proposed landing ellipse. Data from these instruments, along with new MOC images and THEMIS mosaics, will be used to enhance our understanding of the geologic and engineering parameters of each site.

  15. Widespread Layers in Arabia Terra: Implications for Martian Geologic History

    NASA Technical Reports Server (NTRS)

    Venechuk, Elizabeth M.; Oehler, D. Z.

    2006-01-01

    Layered rocks in Arabia Terra have been the focus of several recent papers. Studies have focused on the layers found in crater basins located in the southwest portion of the region. However, Mars Orbiter Camera (MOC) images have identified layered deposits across the region. Terrestrial layered rocks are usually sedimentary, and often deposited in water. Thus extensive layered sequences in Arabia Terra may indicate locations of past, major depositional basins on Mars. Other mechanisms can also create layered rocks, or the appearance of layered rocks, including volcanism (both lava flows and ash falls), wind-blown deposits, and wave-cut terraces at shorelines. By identifying where in the region layers occur, and classifying the layers according to morphology and albedo, past depositional environments may be identified. Arabia Terra is characterized by heavily cratered Noachian plains, as well as a rise from -4000 m in the northwest to 4000 m in the southeast (Mars Orbital Laser Altimeter [MOLA] datum). This slope may have provided a constraint on sediment deposition and thus layer formation. While most of the region is Noachian in age, a significant percentage of the area is identified as Hesperian. Although the history of the Arabia Terra initially seems to be straightforward cratered plains with several younger units atop them analysis of high-resolution imagery may reveal a more complex history.

  16. Discovery of a Plains Caldera Complex and Extinct Lava Lake in Arabia Terra, Mars: Implications for the Discovery of Additional Highland Volcanic Source Regions

    NASA Technical Reports Server (NTRS)

    Bleacher, Jacob; Michalski, Joseph

    2012-01-01

    Several irregularly shaped topographic depressions occur near the dichotomy boundary in northern Arabia Terra, Mars. The geomorphology of these features suggests that they formed by collapse, opposed to meteor impact. At least one depression (approx.55 by 85 km) displays geologic features indicating a complex, multi-stage collapse history. Features within and around the collapse structure indicate volcanic processes. The complex occurs within Hesperian ridged plains of likely volcanic origin and displays no crater rim or evidence for ejecta. Instead the depression consists of a series of circumferential graben and down-dropped blocks which also display upper surfaces similar to ridged plain lavas. Large blocks within the depression are tilted towards the crater center, and display graben that appear to have originally been linked with circumferential graben outside of the complex related to earlier collapse events. A nearly 700 m high mound exists along a graben within the complex that might be a vent. The deepest depression displays two sets of nearly continuous terraces, which we interpret as high-stands of a drained lava lake. These features appear similar to the black ledge described during the Kilauea Iki eruption in 1959. A lacustrine origin for the terraces seems unlikely because of the paucity of channels found in or around the depression that could be linked to aqueous surface processes. In addition, there is no obvious evidence for lacustrine sediments within the basin. Together with the presence of significant faulting that is indicative of collapse we conclude that this crater complex represents a large caldera formed in the Late Noachian to Early Hesperian. Other linear and irregular depressions in the region also might be linked to ancient volcanism. If that hypothesis is correct, it suggests that northern Arabia Terra could contain a large, previously unrecognized highland igneous province. Evacuation of magma via explosive and effusive activity

  17. Geological Time on Display in Arabia Terra

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    This scene from the dust covered plains of eastern Arabia Terra portrays a range of geological time. Three craters at the center of the image capture some of this range. Two have the classic bowl-shape of small, relatively recent craters while the one just to the north has seen much more history. Its rim has been scoured away by erosion and its floor has been filled in by material likely of a sedimentary nature. The channels that wind through the scene may be the oldest features present while the relatively dark streaks scattered about could have been produced in the past few years or even months as winds remove a layer of dust to reveal darker material below.

    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.

  18. Knobby terrain in Northern Arabia Terra

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 25 April 2002) The Science This THEMIS visible image shows a region in northern Arabia Terra near 44o N, 322o W (38o E). Knobby or 'scabby' plains units that mantle and modify a pre-existing cratered surface dominate the unusual landscape in this region. Several large (5-8 km diameter) impact craters seen in the upper left of the image have been extensively modified since their initial formation. The rims of these craters can still be seen, but the ejecta deposits and the surrounding plains have been buried by a layer of material. This mantling layer has itself been modified to produce a pitted, knobby surface. Circular depressions of all sizes, presumably the remnants of impact craters, are filled with smooth deposits. In some places large regions have been covered by this smooth material; an example can be seen in the lower right portion of this image. In many cases the impact craters have been extensively modified prior to their being filled. This modification indicates an erosion process that has removed material from the walls to produce shapes that vary from circular with crisp rims, to circular with no rims, to oblong and elliptical forms, and finally to irregular shapes whose initial circular outline can barely be detected. The slope of the channel at the top of the image has an unusual deposit of material that occurs preferentially on the cold, north-facing slope. Similar deposits are seen frequently at mid-northern and southern latitudes on Mars, and have a characteristic, rounded boundary that typically occurs at approximately the same distance below the ridge crest. It has been suggested that these deposits once draped the entire surface and have since been removed from all but the cold north-facing slopes. The presence and removal of ground ice may play an important role in the formation of this layer, as well as the knobby terrain and unusual features seen in this image. The StoryThere's no way these impact craters are in their original

  19. Peleolakes and impact basins in southern Arabia Terra, including Meridiani Planum: Implications for the formation of hematite deposits on Mars

    USGS Publications Warehouse

    Newsom, Horton E.; Barber, C.A.; Hare, T.M.; Schelble, R.T.; Sutherland, V.A.; Feldman, W.C.

    2003-01-01

    The hematite deposit in Meridiani Planum was selected for a Mars Exploration Rover (MER) landing site because water could be involved in the formation of hematite, and water is a key ingredient in the search for life. Our discovery of a chain of paleolake basins and channels along the southern margin of the hematite deposits in Meridiani Planum with the presence of the strongest hematite signature adjacent to a paleolake basin, supports the possible role of water in the formation of the hematite and the deposition of other layered materials in the region. The hematite may have formed by direct precipitation from lake water, as coatings precipitated from groundwater, or by oxidation of preexisting iron oxide minerals. The paleolake basins were fed by an extensive channel system, originating from an area larger than Texas and located south of the Schiaparelli impact basin. On the basis of stratigraphic relationships, the formation of channels in the region occurred over much of Mars' history, from before the layered materials in Meridiani Planum were deposited until recently. The location of the paleolake basins and channels is connected with the impact cratering history of the region. The earliest structure identified in this study is an ancient circular multiringed basin (800-1600 km diameter) that underlies the entire Meridiani Planum region. The MER landing site is located on the buried northern rim of a later 150 km diameter crater. This crater is partially filled with layered deposits that contained a paleolake in its southern portion. Copyright 2003 by the American Geophysical Union.

  20. Comparing Crustal Magnetism of Terra Meridiani and Terra Cimmeria, Mars

    NASA Astrophysics Data System (ADS)

    French, R. A.; Jurdy, D. M.

    2014-12-01

    Terra Meridiani displays remanent crustal magnetization, roughly symmetric and coherent over long distances, that has been interpreted by some workers as resulting from seafloor spreading. A detailed magnetization map of this region, located at 0º, 0º ±20º, will be compared with that of Terra Cimmeria (-40º, 180º) which hosts Mars' most intense and continuous magnetization. Mars Global Surveyor magnetometer (MGS MAG) data from mapping altitude (~400km) was downward continued to the surface. Data from the MGS aerobraking phase contains tracks in Terra Meridiani at altitudes between 110-190 km, revealing localized persistent Br signatures between -268 and 278 nT, with standard deviations of 24 and 17 nT, respectively. These signatures coincide with areas of strongest magnetization on the downward continued map at corresponding altitudes. However, several uncorrelated small-scale pockets of magnetization that appear in the aerobraking dataset may be attributed to shorter wavelength signals or noise. Positive and negative sources in Terra Meridiani show comparable decay with altitude. Similarly, sources in Terra Cimmeria resemble this decay. By extrapolating into the subsurface, we estimate the source depths for both regions and observe that Terra Meridiani has shallower sources than Terra Cimmeria. The strongest magnetization in Terra Meridiani lies along the 4,600 km diameter outer ring of the Chryse basin. A similar association occurs in Terra Cimmeria along the outer rings of the Sirenum basin. The decay of magnetization intensity with altitude, crustal composition, and crustal thickness estimates will be used to create simple models of magnetic sources for Terra Meridiani.

  1. Radar Scattering Properties of Terra Meridiani, Mars

    NASA Astrophysics Data System (ADS)

    Larsen, K. W.; Haldemann, A. F.; Jurgens, R. F.; Slade, M. A.; Arvidson, R. E.

    2002-12-01

    A series of fourteen radar observations of Mars were made during the 2001 opposition. Four of these observation tracks passed over Terra Meridiani, a prime candidate landing site for one of the 2003 Mars Exploration Rover missions. Observations were conducted using X-band (3.5 centimeter wavelength) radar transmitted with a pseudo-random binary phase encoding which, combined with the frequency resolution of the processing FFT, yields a maximum spatial resolution of approximately five kilometers. Actual spatial resolution is coarser than this (between five and twenty kilometers) due to signal-to-noise considerations that predicated longer integration times as well as greater planetary ranges for the off-opposition observations. We have processed the Terra Meridiani data in stages, beginning with one-dimensional sub-radar track profiles and culminating with four-station interferometry. Not all observations were amendable to the full four-station interferometry, due to technical issues, but were processed with a minimum of two stations to remove the spatial ambiguities inherent to radar observations. Our processing yields one- and two-dimensional maps of the surface reflectivity along the radar track. We extract scattering data for points along the sub-radar track, where the angle in incidence varies most, and model the scattering function. The multi-station reflectivity data is also modeled according to the Hagfors scattering model to extract two-dimensional maps of RMS roughness and dielectric constant. The RMS roughness data for the Terra Meridiani landing sites shows the local surface slopes to be less than 3 degrees, on the scale of tens of wavelengths. An enhanced dielectric constant is apparent over Terra Meridiani that is spatially correlated with the MGS detected hematite deposits. The level of the enhancement is consistent with the inclusion of 10-15 percent hematite, according to a weighted dielectric or PVL model. Integral to our processing, and new to

  2. Extension Across Tempe Terra, Mars from MOLA Topographic Measurements

    NASA Technical Reports Server (NTRS)

    Harrington, B. W.; Phillips, R. J.; Golombek, M. P.

    1999-01-01

    Previously, methods of estimating the extension across grabens and rifts on Mars by necessity relied on photogeologic methods such as shadow measurement, crater ellipticity, or photoclinometry. With the new data being returned by the Mars Global Surveyor, specifically from the Mars Orbital Laser Altimeter (MOLA), it is now possible to directly measure the depths of these structures and therefore to estimate more accurately the amount of extension. Here we provide an example of this new approach in the Tempe Terra region. Additional information is contained in the original extended abstract.

  3. Light-Toned, Layered Outcrops of Northern Terra Meridiani Mars: Viking, Phobos 2, and Mars Global Surveyor Observations

    NASA Technical Reports Server (NTRS)

    Edgett, Kenneth S.

    2002-01-01

    System (PDS). The main body of data examined were Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images acquired through 30 September 2002. The data also 2 include Viking orbiter images, a Phobos 2 Termoscan image, MGS Mars Orbiter Laser Altimeter (MOLA) topographic observations, and the products of published Viking Infrared Thermal Mapper (IRTM) and Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) analyses. Through September 2002, over 126,000 MOC images had been acquired, and greater than 600 of the MOC narrow angle (1.5-12 m/pixel) images occur within the portions of Terra Meridiani and southwestern Arabia Terra.

  4. Vernal Crater, SW Arabia Terra: MSL Candidate with Extensively Layered Sediments, Possible Lake Deposits, and a Long History of Subsurface Ice

    NASA Technical Reports Server (NTRS)

    Oehler, Dorothy Z.; Allen, Carlton C.

    2007-01-01

    Vernal Crater is a Mars Science Laboratory (MSL) landing site candidate providing relatively easy access to extensively layered sediments as well as potential lake deposits. Sediments of Vernal Crater are 400-1200 m below those being investigated by Opportunity in Meridiani Planum, and as such would allow study of significantly older geologic units, if Vernal Crater were selected for MSL. The location of Vernal Crater in SW Arabia Terra provides exceptional scientific interest, as rampart craters and gamma-ray spectrometer (GRS) data from the region suggest a long history of ice/fluids in the subsurface. The potential value of this MSL candidate is further enhanced by reports of atmospheric methane over Arabia, as any insight into the source of that methane would significantly increase our understanding of Mars. Finally, should MSL survive beyond its prime mission, the gentle slope within Vernal Crater would provide a route out of the crater for study of the once ice/fluid-rich plains.

  5. Ancient Giant Basin/Aquifer System in the Arabia Region, Mars

    NASA Technical Reports Server (NTRS)

    Dohm, James M.; Barlow, Nadine; Williams, Jean-Pierre; Baker, Victor R.; Anderson, Robert C.; Boynton, William V.; Fairen, Alberto G.; Hare, Trent M.

    2004-01-01

    Ancient geologic/hydrologic phenomena on Mars observed through the magnetic data [1,2] provide windows to the ancient past through the younger Argyre and Hellas impacts [e.g., 3,4], the northern plains basement [5], and the Tharsis and Elysium magmatic complexes (recently referred to as superplumes [6,7]). These signatures, coupled with highly degraded macrostructures (tectonic features that are tens to thousands of km-long [8]), reflect an energetic planet during its embryonic development (.5 Ga or so of activity) with an active dynamo and magnetosphere [1,2,6]. One such window into the ancient past occurs northwest of the Hellas impact basin in Arabia Terra. Arabia Terra is one of the few water-rich equatorial regions of Mars, as indicated through impact crater [9] and elemental [10,11] information. This region records many unique traits, including stratigraphy, topography, cratering record, structural character, geomorphology, and geophysical, elemental, albedo, and thermal inertia signatures. We interpret these to collectively indicate a possible ancient giant impact basin that later became an important aquifer, as it provided yet another source of water for the formation of putative water bodies that occupied the northern plains [12,13] and addresses possible water-related characteristics that may be observed at the Opportunity landing site. This basin is antipodal to Tharsis and estimated to be at least 3,000 km in diameter.

  6. Braided alluvial fan in the Terra Sirenum region, Mars

    NASA Astrophysics Data System (ADS)

    Adeli, S.; Hauber, E.; Le Deit, L.; Kleinhans, M. G.; Platz, T.; Fawdon, P.; Jaumann, R.

    2015-10-01

    Here we report the presence of an Amazonian-aged outflow channel located on the rim of the Ariadnes Colles basin (37°S/178°E) that has an alluvial fan on its downstream part. The study area is located in the Noachian highlands of Terra Sirenum, the site of a large hypothesized paleolake [3]. This so-called Eridania lake existed during the Late Noachian -Early Hesperian and drained into Ma'adim Vallis, one of the largest valleys on Mars. The Ariadnes Colles basin was part of the Eridania paleolake and hosted later a closed lake.

  7. Identifying the Pre-Tharsis Structures Associated with the Terra Sirenum Region, Mars

    NASA Astrophysics Data System (ADS)

    Anderson, R. C.; Dohm, J. M.; Robbins, S.; Schroeder, J.

    2014-07-01

    The Terra Sirenum region contains some of the oldest stratigraphic units found on Mars. Examination of the structures and units provides an excellent window into clarifying the processes that influenced the early geologic evolution of Mars.

  8. Terra Sirenum: Window into Pre-Tharsis and Tharsis Phases of Mars Evolution

    NASA Astrophysics Data System (ADS)

    Anderson, R. C.; Dohm, J. M.; Robbins, S.; Hynek, B.; Andrews-Hanna, J.

    2012-03-01

    The Terra Sirenum region contains some of the oldest stratigraphic units on Mars. Detailed examination of the structures and units provides an excellent window into identifying the processes that influenced the early geologic evolution of Mars.

  9. MOLA Topography of Small Volcanoes in Tempe Terra and Ceraunius Fossae, Mars: Implications for Eruptive Styles

    NASA Technical Reports Server (NTRS)

    Wong, M. P.; Sakimoto, S. E. H.; Garvin, J. B.

    2001-01-01

    We use Mars Orbiter Laser Altimeter (MOLA) data to measure small volcanoes in the Tempe Terra and Ceraunius Fossae regions of Mars. We find that previous geometry estimates based on imagery alone are inaccurate, but MOLA data support image-based interpretations of eruptive style. Additional information is contained in the original extended abstract.

  10. East Arabia Landforms

    NASA Technical Reports Server (NTRS)

    2005-01-01

    11 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two small mesas, a hill, and other landforms in the highly-eroded landscape of eastern Arabia Terra.

    Location near: 30.0oN, 295.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  11. Hematite and Etched Terrain Distribution in Terra Meridiani, Mars

    NASA Astrophysics Data System (ADS)

    Koeppen, W. C.; Arvidson, R. E.; Seelos, F. P.

    2002-12-01

    Analyses of TES-based bolometric albedo, thermal inertia, and spectral emissivity-derived hematite index for the Hematite region in Terra Meridiani (centered at 1.5 deg S and 3.0 deg W) indicate the terrain to be homogenous at resolutions of 3 km per pixel. In contrast, MOC NA frames with a maximum resolution of ~1.5 meters per pixel show that though the Hematite region is composed primarily of smooth, dark, pervasive dune-forms, there are also exposures of a ubiquitous bright material. This high albedo etched unit is interpreted to be a resistant substrate that extends beyond the borders of the overlying hematite-bearing plains. In order to quantify the relative superficial abundance of bright substrate and dark plains, we conduct high-resolution mapping of the hematite-bearing unit using MOC NA frames processed to ISIS level 2 (map projected with units proportional to radiance on sensor). As an illustrative example, MOC NA E03-01763 exhibits the etched unit in three typical settings: young crater rims, older craters which have lost much of their topographic signature but retain bright rims, and intercrater plains underlying dark, motley dunes. By area, 9.1% of the frame consists of bright material distributed uniformly across the scene. In general, MOC frames from the Hematite unit exhibit bright materials with an areal coverage ranging from 3% to 12%. This analysis demonstrates that the Mars Exploration Rover will be able to perform in-situ analyses of both the dark, hematite-bearing plains and the bright substrate over the course of the primary 90 sol mission.

  12. TERRA.

    ERIC Educational Resources Information Center

    Locke, Kirsty

    1997-01-01

    TERRA (Teaching Ecological Responsibility, Recreation, and Adventure) is an integrated, one-semester, four-course program in environmental science, environmental English, independent geography, and outdoor education for grades 11 and 12 in New Liskeard, Ontario. Program activities include outdoor adventure, environmental research projects,…

  13. The Origin of the Terra Meridiani Sediments: Volatile Transport and the Formation of Sulfate Bearing Layered Deposits on Mars

    NASA Technical Reports Server (NTRS)

    Niles, P.B.

    2008-01-01

    The chemistry, sedimentology, and geology of the Meridiani sedimentary deposits are best explained by eolian reworking of the sublimation residue of a large scale ice/dust deposit. This large ice deposit was located in close proximity to Terra Meridiani and incorporated large amounts of dust, sand, and SO2 aerosols generated by impacts and volcanism during early martian history. Sulfate formation and chemical weathering of the initial igneous material is hypothesized to have occurred inside of the ice when the darker mineral grains were heated by solar radiant energy. This created conditions in which small films of liquid water were created in and around the mineral grains. This water dissolved the SO2 and reacted with the mineral grains forming an acidic environment under low water/rock conditions. Subsequent sublimation of this ice deposit left behind large amounts of weathered sublimation residue which became the source material for the eolian process that deposited the Terra Meridiani deposit. The following features of the Meridiani sediments are best explained by this model: The large scale of the deposit, its mineralogic similarity across large distances, the cation-conservative nature of the weathering processes, the presence of acidic groundwaters on a basaltic planet, the accumulation of a thick sedimentary sequence outside of a topographic basin, and the low water/rock ratio needed to explain the presence of very soluble minerals and elements in the deposit. Remote sensing studies have linked the Meridiani deposits to a number of other martian surface features through mineralogic similarities, geomorphic similarities, and regional associations. These include layered deposits in Arabia Terra, interior layered deposits in the Valles Marineris system, southern Elysium/Aeolis, Amazonis Planitia, and the Hellas basin, Aram Chaos, Aureum Chaos, and Ioni Chaos. The common properties shared by these deposits suggest that all of these deposits share a common

  14. Blueberries on Earth and Mars: Correlations Between Concretions in Navajo Sandstone and Terra Meridiani on Mars.

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Milner, M. W.; Netoff, D.; Dohm, J.; Kalm, V.; Krinsley, D.; Sodhi, R. N.; Anderson, R. C.; Boccia, S.; Malloch, D.; Kapran, B.; Havics, A.

    2008-12-01

    Concretionary Fe-Mn-rich nodular authigenic constituents of Jurassic Navajo sandstone (moki marbles) bear a certain relationship to similar concretionary forms ('blueberries') observed on Mars. Their origin on Earth is considered to invoke variable redox conditions with underground fluids penetrating porous quartz-rich sandstone leading to precipitation of hematite and goethite-rich material from solution, generally forming around a central nucleus of fine particles of quartz and orthoclase, recently verified by XRD and SEM-EDS analyses. At the outer rim/inner nucleus boundary, bulbous lobes of fine-grained quartz often invade and fracture the outer rim armored matrix. The bulbous forms are interpreted to result from fluid explusion from the inner concretionary mass, a response to pressure changes accompanying overburden loading. Moki marbles, harder than enclosing rock, often weather out of in situ sandstone outcrops that form a surface lag deposit of varnished marbles that locally resemble desert pavement. The marbles appear morphologically similar to 'blueberries' identified on the martian surface in Terra Meridiani through the MER-1 Opportunity rover. On Earth, redox fluids responsible for the genesis of marbles may have emanated from deep in the crust (often influenced by magmatic processes). These fluids, cooling to ambient temperatures, may have played a role in the genesis of the cemented outer rim of the concretions. The low frequency of fungi filaments in the marbles, contrasts with a high occurrence in Fe-encrusted sands of the Navajo formation [1], indicating that microbial content is of secondary importance in marble genesis relative to the fluctuating influx of ambient groundwater. Nevertheless, the presence of filaments in terrestrial concretions hints at the possibility of discovering fossil/extant life on Mars, and thus should be considered as prime targets for future reconnaissance missions to Mars. 1] Mahaney, W.C., et al. (2004), Icarus, 171, 39-53.

  15. Water Indicators in Sirenum Terra and Around the Argyre Impact Basin, Mars

    NASA Technical Reports Server (NTRS)

    Stern, J. G.; Frey, H. V.

    2004-01-01

    This study examines the relationships between three temporally distinct indicators of water on Mars: ancient craters with fluidized ejecta, relatively more recent gullies inside those craters, and current abundance of near surface hydrogen around those craters. We find an association between gully occurrence and large-scale geologic features; analysis indicates unique depth/diameter ratios for gullied craters in Sirenum Terra. Numerical comparisons of fluidized and non-fluidized, gullied and non-gullied craters suggest that the Argyre region could have had a near-surface water table that receded before recent times, while Sirenum Terra may have had an ancient water table that persists to this day.

  16. Ancient Giant Basin/Aquifer System in the Arabia Region, Mars, and Its Influence on the Evolution of the Highland-Lowland Boundary

    NASA Technical Reports Server (NTRS)

    Dohm, J. M.; Barlow, N. G.; Williams, Jean-Pierre; Ferris, J. C.; Miyamoto, H.; Baker, V. R.; Boynton, W. V.; Strom, R. G.; Rodriguez, Alexis; Fairen, Alberto G.

    2004-01-01

    Ancient geologic and hydrologic phenomena on Mars observed through the magnetic data provide windows to the ancient past through the younger Argyre and Hellas impacts, the northern plains basement and the rock materials that mantle the basement, and the Tharsis and Elysium magmatic complexes (recently referred to as superplumes). These signatures, coupled with highly degraded macrostructures (tectonic features that energetic planet during its embryonic development (0.5 Ga or so of activity) with an active dynamo and magnetosphere. One such window into the ancient past occurs northwest of the Hellas impact basin in Arabia Tern. Arabia Terra is one of the few water-rich equatorial regions of Mars, as indicated I through impact crater and elemental information. This region records many unique characteristics, including predominately Noachian materials, a highland-lowland boundary region that is distinct from other boundary regions, the presence of very few macrostructures when compared to the rest of the cratered highlands, the largest region of fretted terrain on Mars, outflow channels such as Mamers Valles that do not have obvious origins, and distinct albedo, thermal inertia, gravity, magnetic, and elemental signatures.

  17. Arabia Bridal Veils

    NASA Technical Reports Server (NTRS)

    2006-01-01

    26 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of the stair-stepped, north wall of a crater in Arabia Terra. Light-toned slope streaks have formed as a result of avalanches in the dry, dark dust that mantles both the crater and its adjacent terrain in this scene.

    Location near: 20.0oN, 324.1oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  18. West Arabia Barchans

    NASA Technical Reports Server (NTRS)

    2005-01-01

    16 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows small barchan dunes on the floor of a crater in western Arabia Terra. Similar dunes are found in most of the larger craters of the region. The steepest slopes on these dunes, their slipfaces, point toward the west-southwest, indicating that dominant winds blow from the east-northeast (upper right).

    Location near: 10.9oN, 2.8oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  19. Possible Volcanic Province in Western Promethei Terra, Mars

    NASA Astrophysics Data System (ADS)

    Raitala, J.; Ivanov, M.; Kostama, V.; Korteniemi, J.; Törmänen, T.; Neukum, G.

    2007-12-01

    The western Promethei Terra region (36-50°S, 90-106°E) studied is roughly ~700 km across. It occupies a unique area on the smoothened eastern Hellas basin rim, and consists of two parts: a gentler (~0.07°, eastward of ~97°E) and a steeper (~0.88°, W of ~97°E) regional slope. The Noachian cratered terrain surrounds the region in the NE, E, and S. The large canyons of Harmakhis, Reull and Teviot Valles cut through the central area and the smooth Hesperian plains [1-10] of the western and central areas display a set of features that does not occur elsewhere on the eastern side of the Hellas basin. The plains have multi-layered interiors as seen on the walls of the canyons that cut them. Similar stacks of sub- horizontal layers are seen in other Martian regions with exposed lava plain interiors, for example, in Lunae Planum and Syrtis Major. These are classic volcanic provinces the layered structure of which was formed by successive emplacement of sheet lava flows that followed the general topographic trend. The average visible thickness of the Promethei layers is ~70-80 m and the typical measured canyon wall slope is ~25-30o. This gives an estimate of the thickness of the layers, which is ~35-45 m. The full layer stack thickness, estimated from observations, is ~1.3 km. Consistent with the observed layering, there are narrow wrinkle ridges (WR) that deform the surface of the plains. WR mostly occur in the eastern portion of the area near Reull and Teviot Valles but some of them are seen near Harmakhis Vallis in the west. Additional long straight narrow ridges (widths < km, heights 10s m, lengths 10s km), which occur in mostly NE-SW-oriented groups, are seen on the surface of the plains. The regional topography does not appear to control the distribution of the ridges. Their morphologic characteristics, areal distribution, and close association with the lava plains are consistent with and suggest that the straight ridges may represent exhumed dikes [11], which

  20. Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters

    USGS Publications Warehouse

    Golombek, M.P.; Tanaka, K.L.; Franklin, B.J.

    1996-01-01

    Two independent methods, with no common assumptions, have been used to estimate the extension across the heavily deformed Tempe Terra province of the Tharsis region of Mars. One method uses measurements of normal fault scarp width with average scarp slope data for simple grabens and rifts on Mars to estimate the fault throw, which, combined with sparse fault dip data, can be used to estimate extension. Formal uncertainties in this method are only slightly greater than those in other methods, given that the total uncertainty is dominated by the likely uncertainty in the fault dip (assumed to be 60????15??). Measurement of normal fault scarp widths along two N25??-50??W directed traverses across Tempe Terra both yield about 22??16 km of extension (or ???2% strain across the northern traverse and nearly 3% across the southern one). About three quarters of the extension has occurred during the two main phases of Tharsis-related deformation from Middle/Late Noachian to Early Hesperian and from Late Hesperian to Early Amazonian, with more extension closer to the center of Tharsis during the first phase. Extension across the region was also determined by measuring the elongation and elongation direction of all ancient Noachian impact craters without ejecta blankets, which predate most of the deformation. Results have been corrected for initial non circularity of craters, established from similar measurements of young (post deformation) impact craters, yielding a statistically significant mean strain of 1.96??0.35% in a N38????10??W direction across Tempe Terra (extension of ???20??4, comparable in magnitude and direction to the average result from the scarp measurement method). Both methods indicate an average extension for single normal fault scarps (and shortening across wrinkle ridges for the crater method) of ???100 m. The agreement between the results of the two independent methods in overall extension and average single normal fault extension argues that the average

  1. Sedimentary deposits in Xanthe Terra: Implications for the ancient climate on Mars

    NASA Astrophysics Data System (ADS)

    Hauber, E.; Gwinner, K.; Kleinhans, M.; Reiss, D.; Di Achille, G.; Ori, G.-G.; Scholten, F.; Marinangeli, L.; Jaumann, R.; Neukum, G.

    2009-07-01

    A variety of sedimentary deposits is observed in Xanthe Terra, Mars, including Gilbert-type deltas, fan deltas dominated by resedimentation processes, and alluvial fans. Sediments were provided through deeply incised valleys, which were probably incised by both runoff and groundwater sapping. Mass balances based on High-Resolution Stereo Camera (HRSC) digital terrain models show that up to ˜30% of the material that was eroded in the valleys is present as deltas or alluvial fan deposits. Stratigraphic relationships and crater counts indicate an age of ˜4.0 to ˜3.8 Ga for the fluvial activity. Hydrologic modeling indicates that the deposits were probably formed in geologically very short time scales. Our results point to episodes of a warmer and wetter climate on early Mars, followed by a long period of significantly reduced erosion rates.

  2. Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars

    USGS Publications Warehouse

    Wray, J.J.; Milliken, R.E.; Dundas, C.M.; Swayze, G.A.; Andrews-Hanna, J. C.; Baldridge, A.M.; Chojnacki, M.; Bishop, J.L.; Ehlmann, B.L.; Murchie, S.L.; Clark, R.N.; Seelos, F.P.; Tornabene, L.L.; Squyres, S. W.

    2011-01-01

    Columbus crater in the Terra Sirenum region of the Martian southern highlands contains light-toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate in detail the morphology, thermophysical properties, mineralogy, and stratigraphy of these deposits; explore their regional context; and interpret the crater's aqueous history. Hydrated mineral-bearing deposits occupy a discrete ring around the walls of Columbus crater and are also exposed beneath younger materials, possibly lava flows, on its floor. Widespread minerals identified in the crater include gypsum, polyhydrated and monohydrated Mg/Fe-sulfates, and kaolinite; localized deposits consistent with montmorillonite, Fe/Mg-phyllosilicates, jarosite, alunite, and crystalline ferric oxide or hydroxide are also detected. Thermal emission spectra suggest abundances of these minerals in the tens of percent range. Other craters in northwest Terra Sirenum also contain layered deposits and Al/Fe/Mg-phyllosilicates, but sulfates have so far been found only in Columbus and Cross craters. The region's intercrater plains contain scattered exposures of Al-phyllosilicates and one isolated mound with opaline silica, in addition to more common Fe/Mg-phyllosilicates with chlorides. A Late Noachian age is estimated for the aqueous deposits in Columbus, coinciding with a period of inferred groundwater upwelling and evaporation, which (according to model results reported here) could have formed evaporites in Columbus and other craters in Terra Sirenum. Hypotheses for the origin of these deposits include groundwater cementation of crater-filling sediments and/or direct precipitation from subaerial springs or in a deep (???900 m) paleolake. Especially under the deep lake scenario, which we prefer, chemical gradients in Columbus crater may have created a habitable environment at this location on early Mars. ?? 2011 by the American Geophysical Union.

  3. Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars

    NASA Astrophysics Data System (ADS)

    Wray, J. J.; Milliken, R. E.; Dundas, C. M.; Swayze, G. A.; Andrews-Hanna, J. C.; Baldridge, A. M.; Chojnacki, M.; Bishop, J. L.; Ehlmann, B. L.; Murchie, S. L.; Clark, R. N.; Seelos, F. P.; Tornabene, L. L.; Squyres, S. W.

    2011-01-01

    Columbus crater in the Terra Sirenum region of the Martian southern highlands contains light-toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate in detail the morphology, thermophysical properties, mineralogy, and stratigraphy of these deposits; explore their regional context; and interpret the crater's aqueous history. Hydrated mineral-bearing deposits occupy a discrete ring around the walls of Columbus crater and are also exposed beneath younger materials, possibly lava flows, on its floor. Widespread minerals identified in the crater include gypsum, polyhydrated and monohydrated Mg/Fe-sulfates, and kaolinite; localized deposits consistent with montmorillonite, Fe/Mg-phyllosilicates, jarosite, alunite, and crystalline ferric oxide or hydroxide are also detected. Thermal emission spectra suggest abundances of these minerals in the tens of percent range. Other craters in northwest Terra Sirenum also contain layered deposits and Al/Fe/Mg-phyllosilicates, but sulfates have so far been found only in Columbus and Cross craters. The region's intercrater plains contain scattered exposures of Al-phyllosilicates and one isolated mound with opaline silica, in addition to more common Fe/Mg-phyllosilicates with chlorides. A Late Noachian age is estimated for the aqueous deposits in Columbus, coinciding with a period of inferred groundwater upwelling and evaporation, which (according to model results reported here) could have formed evaporites in Columbus and other craters in Terra Sirenum. Hypotheses for the origin of these deposits include groundwater cementation of crater-filling sediments and/or direct precipitation from subaerial springs or in a deep (˜900 m) paleolake. Especially under the deep lake scenario, which we prefer, chemical gradients in Columbus crater may have created a habitable environment at this location on early Mars.

  4. Characterization of hydrated silicate-bearing outcrops in Tyrrhena Terra, Mars: Implications to the alteration history of Mars

    NASA Astrophysics Data System (ADS)

    Loizeau, D.; Carter, J.; Bouley, S.; Mangold, N.; Poulet, F.; Bibring, J.-P.; Costard, F.; Langevin, Y.; Gondet, B.; Murchie, S. L.

    2012-05-01

    The Tyrrhena Terra region of Mars is studied with the imaging spectrometers OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) onboard Mars Express and CRISM (Compact Reconnaissance Infrared Spectrometer for Mars) onboard Mars Reconnaissance Orbiter, through the observation of tens of craters that impacted into this part of the martian highlands. The 175 detections of hydrated silicates are reported, mainly associated with ejecta blankets, crater walls and rims, and central up-lifts. Sizes of craters where hydrated silicates are detected are highly variable, diameters range from less than 1 km to 42 km. We report the presence of zeolites and phyllosilicates like prehnite, Mg-chlorite, Mg-rich smectites and mixed-layer chlorites-smectites and chlorite-vermiculite from comparison of hyperspectral infrared observations with laboratory spectra. These minerals are associated with fresh craters post-dating any aqueous activity. They likely represent ancient hydrated terrains excavated by the crater-forming impacts, and hence reveal the composition of the altered Noachian crust, although crater-related hydrothermal activity may have played a minor role for the largest craters (>20 km in diameter). Most detected minerals formed over relatively high temperatures (100-300 °C), likely due to aqueous alteration of the Noachian crust by regional low grade metamorphism from the Noachian thermal gradient and/or by extended hydrothermal systems associated with Noachian volcanism and ancient large impact craters. This is in contrast with some other phyllosilicate-bearing regions like Mawrth Vallis where smectites, kaolinites and hydrated silica were mainly identified, pointing to a predominance of surface/shallow sub-surface alteration; and where excavation by impacts played only a minor role. Smooth plains containing hydrated silicates are observed at the boundary between the Noachian altered crust, dissected by fluvial valleys, and the Hesperian

  5. Evidence for Recent Liquid Water on Mars: Gullies in Crater Wall, Noachis Terra

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site]

    Gullies eroded into the wall of a meteor impact crater in Noachis Terra. This high resolution view (top left) from the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) shows channels and associated aprons of debris that are interpreted to have formed by groundwater seepage, surface runoff, and debris flow. The lack of small craters superimposed on the channels and apron deposits indicates that these features are geologically young. It is possible that these gullies indicate that liquid water is present within the martian subsurface today.

    The MOC image was acquired on September 28, 1999. The scene covers an area approximately 3 kilometers (1.9 miles) wide by 6.7 km (4.1 mi) high (note, the aspect ratio is 1.5 to 1.0). Sunlight illuminates this area from the upper left. The image is located near 54.8oS, 342.5oW. The context image (above) shows the location of the MOC image on the south-facing wall of an impact crater approximately 20 kilometers (12 miles) in diameter. The context picture was obtained by the Viking 1 orbiter in 1980 and is illuminated from the upper left. The large mound on the floor of the crater in the context view is a sand dune field. The Mars Orbiter Camera high resolution images are taken black-and-white (grayscale); the color seen here has been synthesized from the colors of Mars observed by the MOC wide angle cameras and by the Viking Orbiters in the late 1970s.

    A brief description of how the color was generated: The MOC narrow angle camera only takes grayscale (black and white) pictures. To create the color versions seen here, we have taken much lower resolution red and blue images acquired by the MOC's wide angle cameras, and by the Viking Orbiter cameras in the 1970s, synthesized a green image by averaging red and blue, and created a pallette of colors that represent the range of colors on Mars. We then use a relationship that correlates color and brightness to assign a color to

  6. Geologic Map of MTM -20012 and -25012 Quadrangles, Margaritifer Terra Region of Mars

    USGS Publications Warehouse

    Grant, J. A.; Wilson, S.A.; Fortezzo, C.M.; Clark, D.A.

    2009-01-01

    Mars Transverse Mercator (MTM) -20012 and -25012 quadrangles (lat 17.5 deg - 27.5 deg S., long 345 deg - 350 deg E.) cover a portion of Margaritifer Terra near the east end of Valles Marineris. The map area consists of a diverse assemblage of geologic surfaces including isolated knobs of rugged mountainous material, heavily cratered and dissected ancient highland material, a variety of plains materials, chaotic terrain materials, and one of the highest densities of preserved valleys and their associated deposits on the planet (Saunders, 1979; Baker, 1982; Phillips and others, 2000, 2001). The map area is centered on a degraded, partially filled, ~200-km-diameter impact structure (lat 22 deg S., long 347.5 deg E.), informally referred to as Parana basin, located between Parana Valles to the east and Loire Valles to the west. Parana Valles is a network of multidigitate, mostly east-west-oriented valleys that flowed west and discharged into Parana basin (Grant, 1987, 2000; Grant and Parker, 2002). Loire Valles, broadly comparable in length to the Grand Canyon on Earth, has a deeply incised channel within the map area that originates at the west-northwest edge of Erythraeum Chaos within Parana basin (Grant, 1987, 2000; Grant and Parker, 2002; Strom and others, 2000). Parana and Loire Valles, combined with Samara Valles to the west, form one of the most laterally extensive, well-integrated valley networks on Mars (Grant, 2000) and record a long history of modification by fluvial processes. The origin and morphology of the valley networks, therefore, provide insight into past environmental conditions, whereas their relation with other landforms helps constrain the timing and role of fluvial processes in the evolution and modification of the Margaritifer Terra region.

  7. Sedimentary deposits in Xanthe Terra: Implications for the ancient climate on Mars

    NASA Astrophysics Data System (ADS)

    Hauber, E.; Gwinner, K.; Kleinhans, M.; Reiss, D.; di Achille, G.; Ori, G.-G.; Scholten, F.; Marinangeli, L.; Jaumann, R.; Neukum, G.

    2008-09-01

    Summary A variety of sedimentary deposits is observed in Xanthe Terra, Mars, including Gilbert-type deltas, fan deltas dominated by resedimentation processes, and alluvial fans. Sediments were provided through deeply incised valleys, which were probably incised by both runoff and groundwater sapping. Mass balances based on high-resolution HRSC digital terrain models show that up to ~30% of the material that was eroded in the valleys is present as deltas or alluvial fan deposits. Stratigraphic relationships and crater counts indicate an age of ~4.0 to ~3.8 Ga for the fluvial activity. Hydrologic modeling indicates that the deposits were probably formed in geologically very short time-scales. Our results indicate episodes of a warmer and wetter climate on early Mars, followed by a long period of significantly reduced erosion rates. Background Fluvial and lacustrine deposits on Mars contain a record of past hydrological conditions and are important targets of environmental and paleoclimatic studies. Ancient depositional landforms associated with fluvial channels are generally thought to indicate an active hydrosphere, involving precipitation, runoff, and significant erosion. However, the exact nature of the flow processes and the time-scales over which they occurred are under debate. End-member scenarios are represented by an early Mars that was either wet and warm or cold and dry. The analysis of sedimentary deposits can constrain paleohydrological models. For example, a warmer climate and persistent flow would have been required if they were formed in long-standing paleolakes. Alternatively, fans and deltas might have formed under subaerial conditions or in short-lived lakes. Therefore, the determination of the time when such deposits were formed in Mars` history, the duration of the fluvial activity, and the type of sedimentary environment is a critical component of paleoclimatic studies of Mars. Data The High Resolution Stereo Camera (HRSC) on the Mars Express

  8. Detailed spectroscopic analysis of chloride salt deposits in Terra Sirenum, Mars

    NASA Astrophysics Data System (ADS)

    Osterloo, M. M.; Glotch, T. D.; Bandfield, J. L.

    2015-12-01

    Chloride salt-bearing deposits have been identified throughout the southern highlands of Mars [1] based on the lack of diagnostic spectral features of anhydrous chlorides in both the visible near infrared (VNIR) and middle infrared (MIR) wavelength ranges [1,2]. A puzzling aspect of martian chloride deposits is the apparent lack of other weathering or evaporite phases associated with most of the deposits. A global analysis over the chloride salt sites conducted by [3] found that only ~9% of the deposits they analyzed were associated with minerals such as phyllosilicates. Most of these occurrences are in Terra Sirenum where [4] noted that salt-bearing deposits lie stratigraphically above Noachian phyllosilicates. Although a variety of formation mechanisms have been proposed for these intriguing deposits, detailed geologic mapping by [5] suggests that surface water and evaporation played a dominant role. On Earth, evaporative settings are often characterized by a multitude of evaporite and phyllosilicate phases including carbonates, sulfates, and nitrates. [6] evaluated chemical divides and brine evolution for martian systems and their results indicate three pathways wherein late-stage brines favor chloride precipitation. In each case the pathway to chloride formation includes precipitation of carbonates (calcite, siderite, and/or magnesite) and sulfates (gypsum, melanterite, and/or epsomite). Here, we present the results of our detailed and systematic spectroscopic study to identify additional evaporite phases associated with salt/silicate mixtures in Terra Sirenum. [1] Osterloo et al. (2008) Science, 319, [2] Glotch, T. D. et al. (2013) Lunar and Planet. Sci. XLIV, abstract #1549 [3] Ruesch, O. et al. (2012), J. Geophys. Res., 117, E00J13 [4] Glotch, T. D. et al. (2010) Geophys. Res. Lett. 37, L16202, [5] Osterloo, M. M. and B. M Hynek (2015) Lunar and Planet. Sci XLVI. Abstract #1054 [6] Tosca, N. J. and S. M. McLennan (2006), Earth and Planet. Sci. Lett., 241.

  9. Analysis of crater valleys, Noachis Terra, Mars: Evidence of fluvial and glacial processes

    NASA Astrophysics Data System (ADS)

    Hobbs, S. W.; Clarke, J. D. A.; Paull, D. J.

    2016-05-01

    The precise mechanism for the formation and evolution of crater valley networks in the Martian southern highlands remains under debate, with precipitation, groundwater flow, and melting induced by impact being suggested. We studied valley networks within four craters of the Noachis Terra highlands that were representative of similar features in Noachis Terra and where orbital data existed for analysis in order to characterise their morphology and infer possible processes involved in their formation and evolution. We found evidence for valleys carved by liquid water and ice-related processes. This included strong evidence of liquid water-based valley formation through melting of ice-rich deposits throughout our study area, suggesting an alternative to previously suggested rainfall or groundwater-based scenarios. The location of these valleys on steeply sloping crater walls, as opposed to the shallow slopes of the highlands where Martian valleys are typically found, suggested that our 'fluvial' valleys had not evolved a more structured fluvial morphology as valley networks found on the Martian plains. Our studied valleys' association with ice-rich material and abundant evidence for erosion caused by downslope flow of ice-rich material are consistent with a cold, wet Mars hypothesis where accumulation, flow, and melting of ice have been dominant factors in eroding crater valleys. Additionally, analysis of valley morphology with slope and aspect suggested a greater dependence on local geology and presence of volatiles than larger valley networks, though ice-related valleys were consistently wider for their length than valleys assessed as fluvial carved. We assessed that local conditions such as climate, geology, and availability of ice-rich material played a major role in the erosion of crater valleys at our study site.

  10. Possible crater-based karstic and lacustrine terrain in Tyrrhena Terra, Mars.

    NASA Astrophysics Data System (ADS)

    Baioni, Davide; Soare, Richard

    2015-04-01

    We have identified two craters in Tyrrhena Terra, Mars (19.560 S, 67.480 E, 18.500 S, 68.340 E), where crater-floor deposits display traits that are consistent with formation by karst-driven processes. Tyrrhena Terra is located in the cratered highlands of the southern Martian hemisphere, immediately to the northeast of Hellas Planitia and to the southeast of Isidis Planitia. Crater diameters in the region vary widely, from metres to 100km. Most of these craters are moderately to highly degraded and many show bright deposits on their floors. Here, we present some of the key characteristics associated with these bright deposits and explain why a "karstic" formation hypothesis is reasonable. First and foremost amongst these characteristics are depressions that are ubiquitous within the bright deposits. They display a variety of plan forms ranging from rounded, circular, elongated, polygonal and drop-like to elliptical. Moreover, they display strong morphometric (sizes) and morphologic (shapes, bottoms, walls) similarities with the karst depressions that are common on limestone and evaporite terrains on the Earth. Some depression morphologies - rounded/elongate - could be the result of formation by coalescence. We infer that the depressions are dolines, karstic features formed polygenetically by corrosion and solution-related intra-crater processes; we also demonstrate why the formation of the depressions by aeolian, periglacial, volcanic or impact-related processes seems less plausible by karst-related ones. Interestingly, polygonal cracks whose morphology points to an origin by dessication often cross-cut the bright deposits; as such, their crater floor presence could be an important co-marker of ponded or running liquid water within the craters where they are observed.

  11. Analysis of Ice-Related Intra-Crater Facies in Promethei Terra, Mars

    NASA Astrophysics Data System (ADS)

    Orgel, Csilla; Kereszturi, Ákos; van Gasselt, Stephan

    2014-05-01

    On Mars ice-related landforms have been identified at mid-latitudes between 30° and 50° in both hemispheres including the areas of Tempe Terra, Deuteronilus-Protonilus Mensae, Phlegra Montes and the rims of the southern-hemispheric impact basins Argyre and Hellas [1-7]. Our study area - informally termed hourglass-shaped crater [8] - is located near Reull Vallis on the eastern rim of the Hellas impact basin (39.0°S, 102.8°E). Impact-crater infill was described as debris-covered piedmont-type glacier [8] based on analysis of High Resolution Stereo Camera (HRSC) data, and implies a glacial origin with precipitation of ice during higher obliquity phases. Recent, higher-resolution image data such as data of the High Resolution Imaging Science Experiment (HiRISE) and the Context Imager (CTX) provide a more detailed picture of the lateral distribution of different small-scale surface features indicative of periglacial and/or glacial origin. The aim of this study is to identify qualitative and quantitative characteristics of these ice-related landforms and to separate sources of water ice and related processes. Initial age determinations based on impact-crater size-frequency statistics indicate an age of 3.4 Gyr for the impact-crater and an age of approximately 75 Myr for the infill [8]. In order to identify a possible sequence of surface-feature evolution we calculated the age distribution of four major surface units which span ages ages between 1-47 Myr. Along with detailed age information and a separation of different processes at this confined type location of Mars young-Amazonian landscape evolution and potential cyclic signals are being reconstructed to constrain climate evolution. Carr, M. H. & Schaber, G. G. 1977: Martian permafrost features.- J. Geophys. Res. 82, 4039-4054. Squyres, S. W. 1978: Martian fretted terrain: flow of erosional debris.- Icarus 34, 600-613. Squyres, S. W. 1979: The distribution of lobate debris aprons and similar flows on Mars.- J

  12. New Mineralogic Diversity in the Noachian Crust of Tyrrhena Terra, Mars

    NASA Astrophysics Data System (ADS)

    Seelos, K. D.; Seelos, F. P., IV; Viviano-Beck, C.; Murchie, S. L.

    2015-12-01

    The cratered Noachian highlands region of Mars is host to hundreds to thousands of exposures of hydrated minerals. Areas of the highlands that are relatively free of dust, such as Tyrrhena Terra, have been previously examined using Mars Express/OMEGA and MRO/CRISM visible/near-IR reflectance data. The inferred alteration mineralogy is consistent with formation under low water to rock ratio, relatively low T/P and shallow crustal conditions. The vast majority of occurrences are associated with impact craters with a wide range of diameters, and within not only central peaks, but also rims and ejecta. This implies that most outcrops are a result of the excavation of pre-existing mineralology, not formation in-situ by post-impact hydrothermalism. Types of minerals reported include, most commonly, Fe/Mg phyllosilicates (smectite, chlorite, mixed-layer clays, prehnite, serpentine, illite), and less commonly, Al-phyllosilicates (e.g., kaolinite), carbonates, zeolites (e.g., analcime), and hydrated silica. Here we document and characterize the occurrence of an additional class of mineralogy in Noachian terrain: hydrated sulfates. Hydrated sulfates are observed in the central peaks and (in one case) the proximal ejecta of 3 craters dispersed across the region. In each crater, a diverse assemblage of other hydrated alteration minerals is also apparent and includes prehnite, carbonate, zeolite, Fe/Mg smectite, and chlorite. Two of the three craters are approximately 10 km in diameter, with resulting sulfate exhumation depths in the central peaks approaching 1 km. The third crater has a diameter of 25 km; however, uplift and ejecta from several pre-existing impacts reduce the possible sulfate excavation depth to 1.3 km. CRISM spectra are consistent with a poly-hydrated sulfate, with major absorptions centered at 1.45, 1.95, and 2.4 micrometers - similar to, but distinct from, many zeolites. While mono-hydrated and poly-hydrated sulfates are not uncommon to other areas of Mars

  13. Exploration Zone for Human Mission to Mars: The Area South of Firsoff Crater in Arabia Terra

    NASA Astrophysics Data System (ADS)

    Ori, G. G.; Pondrelli, M.

    2015-10-01

    We are proposing an area south of Firsoff Crater that scientifically includes: reconstruction of the stratigraphy at global scale, the identification of sedimentary environment and paleoclimatic conditions and large astrobiological potentiality.

  14. Sediments of Arabia

    NASA Technical Reports Server (NTRS)

    2005-01-01

    21 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows martian sediment in two basic forms: (1) light-toned, layered, sedimentary rock outcrops and (2) dark, windblown sand dunes. The dark sand of the dunes is most likely composed of grains rich in iron-, magnesium-, aluminum-, and silicon-bearing minerals. The hills and mounds of layered sedimentary rock were once more extensive, covering the entire scene shown here, which occurs on the floor of a crater in western Arabia Terra.

    Location near: 8.9oN, 1.2oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  15. Detection and context of hydrated mineralogy in the Tyrrhena Terra region, Mars

    NASA Astrophysics Data System (ADS)

    den Haan, J.; Zegers, T. E.; van Ruitenbeek, F. J. A.; van der Werff, H. M. A.; Rossi, A.

    2008-09-01

    Introduction The discovery of phyllosilicates on Mars [1] has had major implications on the perceived geologic and climatologic evolution of Mars [2]. Not only do phyllosilicates represent a `wet' period on Mars, they might also represent a potentially favorable environment for life. The phyllosilicates have so far exclusively been found in or close to ancient Noachian highland terrain. Those phyllosilicate deposits studied (e.g. [3]) show a clear association between hydrated mineralogy and heavily eroded and crater-saturated outcrops. Phyllosilicates on Earth are associated with a wide variety of geological processes (volcanism, metamorphism, hydrothermal alteration, sedimentation). The occurrence of phyllosilicates on Mars may be equally diverse in nature. To be able to place constraints on the early Martian environment, the processes by which these phyllosilicates formed need to be reconstructed. To derive this information from individual phyllosilicate deposits, it is necessary to interpret their composition in relation to their geological context and relative time relationships. We conducted such an integrated hyperspectral and geological study of the Tyrrhena Terra region. Data products ad methods HRSC data products (both image at 12 m/pixel and stereo-derived DTMs) are used for examining geologic cross-cutting relationships, geomorphologic landforms and visual determination of unit boundaries. Odyssey THEMIS nighttime TIR images are analyzed for spatial variations in thermal inertia. Where available, HRSC is supplemented by higher-resolution visible observations of CTX or MOC. Hyperspectral analysis is conducted using data from the OMEGA hyperspectral instrument. In order to batch-process large amounts of OMEGA data, an IDL/ENVI tool was developed on top of the existing SOFT04, distributed by PSA. The applied atmospheric correction assumes that atmospheric contributions are multiplicative, and follow a power-law distribution with altitude [4]. The ratio of

  16. Comparison of Plains Volcanism in the Tempe Terra Region of Mars to the Eastern Snake River Plains, Idaho with Implications for Geochemical Constraints

    NASA Technical Reports Server (NTRS)

    Weren, S. L.; Sakimoto, S. E. H.; Hughes, S. S.; Gregg, T. K. P.

    2004-01-01

    The Eastern Snake River Plains (ESRP) in Idaho have long been considered a terrestrial analog for the plains volcanism like that evident in Syria Planum and Tempe Terra, Mars. Both the ESRP and Tempe Terra are sediment-blanketed volcanic fields in areas with significant extensional faulting. Similar volcanic features can be observed throughout both study areas using field analysis and DEMs of the ESRP and the Mars Global Surveyor (MGS) data from Mars. These features include flow fields, low shields, shields with steep summits, and fissure eruptions. A few other volcanic features, such as cinder cones, which suggest variable compositions, volatile interactions, and multiple volcanic events can be seen in both areas. The eruptions in both the ESRP and Tempe Terra generally originate from the fissures creating elongate, multi-vent shields as well as isolated or aligned single vent shields. Many of these show evidence of radial flow patterns from summit craters as well as lava tube fed flows. The volcanoes of Tempe Terra display some of the global latitudinal parameter trends of small volcanoes on Mars. Some of these trends may be explained by the variation of volatile content and compositional variation across Mars. However, within Tempe Terra no significant local latitudinal trends can be seen in edifice attributes and not all variations are explained by global trends. This study builds upon previous studies of the Tempe Terra region and the ESRP in order to develop a more detailed representation of features and topographic data. Using these data we attempt to help constrain the composition and eruptive style of the Tempe Terra volcanoes by correlating them with the similar and quantified ESRP variations.

  17. THEMIS and MOLA Provide 3-D Stratigraphy in the Terra Meridiani Region of Mars

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

    The layered rocks observed in the vicinity of the Mars Exploration Rover (MER) Opportunity landing site are part of a vast stratigraphic complex exposed over ~3×105km2, encompassing 20° of longitude [Hynek, 2004, Nature]. We have used elevations derived from geoid- and orbit-corrected individual MOLA laser shots to determine the three-dimensional disposition of individual stratigraphic horizons exposed within the complex and as mapped with 100 m/pix THEMIS thermal inertia images (high inertia areas correspond to ``etched terrain''). The Opportunity landing site is near the NW edge of an elongated NE-trending topographic bench that contains the hematite-rich plains unit and is about 500 km wide. Mappable stratigraphic exposures occur mostly in two groups, one near the base of the upward slope (to the Arabia Highlands) on the SE side of the bench and one near the top of the downward slope (to the Northern Lowlands) on the NW side of the bench. The total thickness of the stratigraphic complex is ~1000 m. We fit least-squares planes to individual horizons and tested for quality of fit. Our main interest is the orientations of the planes, so the probability density function of the tangent of the dip azimuth was used as a discriminator for solution acceptance (dip azimuth error range < 30°). Of the 22 horizons sampled, 14 had acceptable solutions. The 14 individual stratigraphic horizons are spatially extensive, with maximum MOLA sampling separations in a given horizon being as much as 200 km (mean for all horizons is 80 km). This implies that the depositional environment for these units was coherent over a scale of typically 100 km. Of the 14 acceptable horizons, 10 have shallow dip azimuths in the direction N to NW, consistent with the long-wavelength (regional) slope, which itself is the result of the global pole-to-pole slope plus Noachian-aged Tharsis-induced membrane deformation [Phillips et al., 2001, Science]. The stratigraphic complex both overlies and is

  18. Evaluation of Surface Slope Effects on Ripple Orientations Observed on Sand Dunes in the Terra Tyrrhena Region of Mars

    NASA Astrophysics Data System (ADS)

    Zimbelman, J. R.; Johnson, M. B.

    2014-12-01

    The High Resolution Imaging Science Experiment (HiRISE) has revealed abundant wind ripples on sand dunes across Mars. Ripple orientations have been documented using HiRISE images of sand dunes at 24 widely distributed sites across Mars, in order to identify the last significant wind directions at these locations. Howard (GSAB, 1977) gives a mathematical expression for how surface slopes on a sand dune can affect the orientation of ripples with respect to the formative winds. In order to evaluate this mechanism for measured ripple orientations on Mars, quantitative data for surface slopes on the sand dunes is required. Stereo pairs of HiRISE images are used to generate Digital Terrain Models (DTMs) with postings of one meter. In June 2014 we produced a DTM of sand dunes in the Terra Tyrrhena region of Mars (14.55° S, 97.77° E) using SOCET SET at the Astrogeology Branch, USGS-Flagstaff. Typically it is difficult for feature matching software to work well on sand dunes, but our stereo images (ESP_022609_1655 and ESP_026675_1655) were obtained only six Earth days apart under excellent illumination conditions. The Terra Tyrrhena DTM had remarkably few artifacts on the sand dunes (except at slip faces, where the average slope between slip face crest and base was interpolated) and excellent control from irregular terrain exposed in interdune areas. Slopes on the stoss sides of sand dunes are generally <10°; the Howard equation indicates ripple deflection angles should be <17° with respect to the actual surface wind direction. We are adjusting documented ripple orientations to account for surface slopes utilizing the DTM data, and so far we do not see major changes to inferred surface wind directions that would be derived directly from the ripple orientations.

  19. Geology of Libya Montes and the Interbasin Plains of Northern Tyrrhena Terra, Mars: Project Introduction and First Year Work Plan

    NASA Technical Reports Server (NTRS)

    Skiner, J. A., Jr.; Rogers, A. D.; Seelos, K. D.

    2009-01-01

    The highland-lowland boundary (HLB) of Mars is interpreted to be a complex tectonic and erosional transition that may hold evidence for past geologic processes and environments. The HLB-abutting margin of the Libya Montes and the interbasin plains of northern Tyrrhena Terra display an exceptional view of the earliest to middle history of Mars that has yet to be fully characterized. This region contains some of the oldest exposed materials on the Martian surface as well as aqueous mineral signatures that may be potential chemical artifacts of early highland formational processes. However, a full understanding of the regions geologic and stratigraphic evolution is remarkably lacking. Some outstanding questions regarding the geologic evolution of Libya Montes and northern Tyrrhena Terra in-clude: Does combining geomorphology and composition advance our understanding of the region s evolution? Can highland materials be subdivided into stratigraphically discrete rock and sediment sequences? What do major physiographic transitions imply about the balanced tectonism, climate change, and erosion? Where is the erosional origin and what is the post-depositional history of channel and plains units? When and in what types of environments did aqueous mineral signatures arise? This abstract introduces the geologic setting, science rationale, and first year work plan of a recently-funded 4-year geologic mapping proposal (project year = calendar year). The objective is to delineate the geologic evolution of Libya Montes and northern Tyrrhena Terra at 1:1M scale using both classical geomorphological and compositional mapping techniques. The funded quadrangles are MTMs 00282, -05282, -10282, 00277, -05277, and -10277.

  20. Multiple Episodes of Recent Gully Activity Indicated by Gully Fan Stratigraphy in Eastern Promethei Terra, Mars.

    NASA Astrophysics Data System (ADS)

    Schon, S.; Head, J.; Fassett, C.

    2008-09-01

    Introduction Gullies are considered among the youngest geomorphic features on Mars based upon their stratigraphic relationships, superposition on steep slopes and distinctive morphology in unconsolidated sediment. Multiple formation hypotheses have been proposed, which can be divided into three broad classes: entirely dry mechanisms (e.g., [1,2]), wet mechanisms invoking groundwater or ground ice (e.g., [3,4]) and wet mechanisms invoking surficial meltwater (e.g., [5,6,7,8]). It has been difficult to differentiate between these hypotheses based upon past observations and it remains possible that gullies are polygenetic landforms. This study presents stratigraphic relationships in the depositional fan of a crater wall gully system that suggest: (1) multiple episodes of alluvial fan-style deposition, (2) very recent depositional activity that is younger than a newly recognized rayed crater, and (3) surficial snowmelt as the most likely source of these multiple episodes of recent gully activity. Gully-Fan Stratigraphy In Eastern Promethei Terra an ~5 km-diameter crater is observed with a well-developed gully system (Fig. 1) and several smaller gullies in its northnortheast wall. The large gully system (composed of a small western gully and larger eastern gully) shows evidence for incision into the crater wall country rock and has multiple contributory sub-alcoves and channels. The depositional fan associated with this gully system is bounded on its western side by a small arcuate ridge swell that is not observed on the eastern side of the fan. This ridge is interpreted as a moraine-like structure that may have bounded a glacially-formed depression into which the fan is deposited [8]. Similar depressions with bounding ridges are commonly observed in this latitude band (~30-50°S) in association with deeply incised gully alcoves [9,10,11]. This gully fan is composed of multiple lobes with distinct lobe contacts, incised channels, and cut-andfill deposits - all features

  1. Fluvial channels in the north-western part of Noachis Terra, Mars: Implications for tectonic controls

    NASA Astrophysics Data System (ADS)

    De, K.; Dasgupta, N.; Kundu, A.; Chauhan, P.

    2015-10-01

    Palaeochannels in the western part of Noachis Terra are mapped to understand their origin and also the control on their courses. Relation to impact craters, trends and cross- correlations between their paths indicates to impact-related origin and tectonic lineament controlled courses for the rivers.

  2. Thermal Inertia, Albedo, and MOLA-derived Roughness for Terrains in the Terra Meridiani Area, Mars

    NASA Technical Reports Server (NTRS)

    Arvidson, R. E.; Deal, K.; Hynek, B. M.; Seelos, F. P., IV; Snider, N. O.; Mellon, M. T.; Garvin, J. B.

    2002-01-01

    Surface properties of layered deposits draped on dissected, cratered terrain in the Terra Meridiani area are analyzed using remote sensing data. The etched plains are cemented and differentially eroded, and the hematite plains are loose and drifting. Additional information is contained in the original extended abstract.

  3. Evidence for Noachian flood volcanism in Noachis Terra, Mars, and the possible role of Hellas impact basin tectonics

    NASA Astrophysics Data System (ADS)

    Rogers, A. D.; Nazarian, A. H.

    2013-05-01

    Spectral and imaging data sets from Mars Reconnaissance Orbiter and Mars Odyssey, as well as spectral and topographic data from Mars Global Surveyor, are used to understand the origin of in-place rock units found in the intercrater plains and Hellas circumferential graben floors of Noachis Terra, Mars. The rocky units are interpreted as effusive volcanic plains on the basis of broad areal extent, structural competence, association with topographic lows, distinct mineralogy from regolith, and lack of sedimentary textures or minerals associated with aqueous processes. Some rocky expanses contain at least two compositionally distinct units. The relatively light-toned unit exhibits a higher plagioclase/pyroxene ratio than the lower, dark-toned unit. Both units exhibit ~10% olivine enrichment compared to surrounding regolith. These units are heavily degraded and exhibit crater model ages between ~3.80 and 4.0 Ga, making these some of the oldest preserved volcanic plains accessible by remote sensing. They are found in association with Hellas ring structures, where the westward extent of these rocky units is limited to the outermost ring structure. Fracturing associated with the Hellas impact may have enabled magmas to ascend from the base of the crust in the circum-Hellas region. Identification of these units as volcanic materials extends previous estimates for volume of outgassed volatiles. Though the estimated volcanic volume increase is minor, the local effects could have been significant. The role of multi-ring impact basins in providing a spatial control on Martian highlands volcanism and subsurface mineralization may have been underestimated in the past.

  4. Geology of Holden Crater and the Holden and Ladon Multi-Ring Impact Basins, Margaritifer Terra, Mars

    NASA Technical Reports Server (NTRS)

    Irwin, R. P., III; Grant, J. A.

    2008-01-01

    Geologic mapping at 1:500K scale of Mars quads 15s027, 20s027, 25s027, and 25s032 (Fig. 1) is in progress to constrain the geologic and geomorphic history of southwestern Margaritifer Terra. This work builds on earlier maps at 1:5M [1] and 1:15M scales [2], recent to concurrent 1:500Kscale mapping of adjacent areas to the east [3-5], and studies of drainage basin evolution along the Uzboi-Ladon-M (ULM; the third valley in the sequence has no formal name) Valles basin overflow system and nearby watersheds [6-9]. Two of the six landing sites under consideration for the Mars Science Laboratory rover are in this map area, targeting finely layered, phyllosilicate-rich strata and alluvial fans in Holden crater [10-12] (26degS, 34degW, 150 km diameter) or deposits southeast of a likely delta in Eberswalde crater [13-16] (24degS, 33degW, 50 km in diameter). Diverse processes including larger and smaller impacts, a wide range in fluvial activity, and local to regional structural influences have all affected the surface morphology.

  5. Blueberries on Earth and Mars: Some Correlations Between Andean Paleosols, Geothermal Pipes in Navajo Sandstone and Terra Meridiani on Mars

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Milner, M. W.; Netoff, D. I.; Dohm, J. M.; Sodhi, R. N. S.; Aufreiter, S.; Hancock, R. G. V.; Bezada, M.; Kalm, V.; Malloch, D.

    2006-03-01

    The origin of "blueberries" on Mars and their relationship to similar concretionary forms on Earth invokes a process of variable redox conditions in underground fluids. The possible role of microorganisms in the origin of bluberries opens an avenue for biological investigations.

  6. Fluvial Degradation of the Highlands: The Terra Tyrrhena Region of Mars

    NASA Technical Reports Server (NTRS)

    Mest, S. C.; Crown, D. A.; Harbert, W.

    2002-01-01

    Geologic and geomorphic analyses of highland terrains reveal the effects of fluvial erosion by well-integrated valley networks. Hydrologic modeling using 128 pix/deg Mars Orbiting Laser Altimeter (MOLA) gridded topography is being done to quantitatively characterize these systems. Additional information is contained in the original extended abstract.

  7. Multi-agent gully processes: Evidence from the Monaro Volcanic Province, Australia and in Terra Cimmeria, Mars

    NASA Astrophysics Data System (ADS)

    Hobbs, S. W.; Paull, D. J.; Clarke, J. D. A.; Roach, Ian C.

    2016-03-01

    Comparison of the similarities and differences between terrestrial and Martian hillside gullies promotes understanding of how surface processes operate on both planets. Here we tested the viability of subsurface flow of water as a process affecting gully evolution. We compared gullies within the Monaro Volcanic Province near Cooma, New South Wales, Australia, to gullies possessing strong structural control near Gasa Crater, Terra Cimmeria, Mars. Although cursory examination of the Monaro gullies initially suggested strong evidence for aquifer erosion, detailed field surveys showed the evidence to be ambiguous. Instead a complex regime of erosion dependent on multiple conditions and processes such as local geology, surface runoff, dry mass wasting, and animal activity emerged. We found the morphology of gullies near Gasa Crater to be consistent with erosion caused by liquid water, while also being heavily influenced by the local environment, including slope and geology. Additionally, erosion at the Martian site was not consistent with evidence of subsequent, smaller scale erosion and channel modification by dry mass wasting. Local conditions thus play an important role in gully evolution, further highlighting that processes forming Martian gullies may be more diverse than initially thought.

  8. Hydrological evolution of Atlantis basin, Sirenum Terrae, Mars. Preliminar analysis of MOC and THEMIS images.

    NASA Astrophysics Data System (ADS)

    de Pablo, M. A.; Márquez, A.; Centeno, J. D.

    The Atlantis basin is one of the martian highlands areas where there was proposed the existence of an ancient lake during the early geological history of Mars [1] [2] [3] [4]. The existence of some morphological features inside the basin and in the surrounding area, allow to check the existence of liquid water in the past of the planet. On the other hand, other morphological features indicate the existence of snow and liquid groundwater in recent times. The detailed study of the geomorphologic features allows to make an approach to the hydrological evolution of the Atlantis basin. The study of the geomorphology of this region has been carried out by means of the analysis of MOC high resolution images obtained by the Mars Global Surveyor mission and the THEMIS images, in the visible spectrum, sent by Mars Odyssey spacecrafts. The most clearly morphological feature indicative of the existence of water in the surface of Mars in the past are the numerous channels that end into Atlantis basin from the highest terrains. In addiction to these fluvial channels, the existence of mass flow deposits is also indicative of the existence of water in the area. Some of these slumps are in the internal slopes of impact craters, but others cover huge extensions around the chaotic terrains of the studied area. The lobated ejecta deposits observed in the Atlantis basin region are indicative of the existence of groundwater (solid or liquid) [5]. Serrated reliefs and tables in the borders of the basins are indicative of the existence of a water sheet. Beneath this water sheet some deposits was formed which was eroded, due to the gradual desiccation of the basin, forming the tables and serrated reliefs. The existence of different chaotic terrains in the area implies the existence of huge amounts of water under the surface according to the different models of chaotic terrain formation [6] [7]. The existence of groundwater could be decided by the existence of collapses in the near to the

  9. Hydrological evolution of Atlantis basin, Sirenum Terrae, Mars. Preliminar analysis of MOC and THEMIS images.

    NASA Astrophysics Data System (ADS)

    de Pablo, M. A.; Márquez, A.; Centeno, J. D.

    The Atlantis basin is one of the martian highlands areas where there was proposed the existence of an ancient lake during the early geological history of Mars [1] [2] [3] [4]. The existence of some morphological features inside the basin and in the surrounding area, allow to check the existence of liquid water in the past of the planet. On the other hand, other morphological features indicate the existence of snow and liquid groundwater in recent times. The detailed study of the geomorphologic features allows to make an approach to the hydrological evolution of the Atlantis basin. The study of the geomorphology of this region has been carried out by means of the analysis of MOC high resolution images obtained by the Mars Global Surveyor mission and the THEMIS images, in the visible spectrum, sent by Mars Odyssey spacecrafts. The most clearly morphological feature indicative of the existence of water in the surface of Mars in the past are the numerous channels that end into Atlantis basin from the highest terrains. In addiction to these fluvial channels, the existence of mass flow deposits is also indicative of the existence of water in the area. Some of these slumps are in the internal slopes of impact craters, but others cover huge extensions around the chaotic terrains of the studied area. The lobated ejecta deposits observed in the Atlantis basin region are indicative of the existence of groundwater (solid or liquid) [5]. Serrated reliefs and tables in the borders of the basins are indicative of the existence of a water sheet. Beneath this water sheet some deposits was formed which was eroded, due to the gradual desiccation of the basin, forming the tables and serrated reliefs. The existence of different chaotic terrains in the area implies the existence of huge amounts of water under the surface according to the different models of chaotic terrain formation [6] [7]. The existence of groundwater could be decided by the existence of collapses in the near to the

  10. Analysis of regional gullies within Noachis Terra, Mars: A complex relationship between slope, surface material and aspect

    NASA Astrophysics Data System (ADS)

    Hobbs, S. W.; Paull, D. J.; Clarke, J. D. A.

    2015-04-01

    The precise mechanisms by which martian hillside gullies erode and their dependence on the local environment remain subjects of debate. We studied three sharp rimmed craters in Noachis Terra and 37 gully profiles using Context Camera (CTX), Mars Orbiter Laser Altimeter (MOLA) and High Resolution Stereo Camera (HRSC) data. We analysed the gully topographic profiles of seven gullies and nine dry ravines. We measured slope properties using HRSC elevation data and used thermal inertia to infer material types of the gully sites. We compared these with three nearby Noachian age craters possessing crater wall slope angles within the range of previously observed gully formations. In-line with previous findings on individual gullies, we found that the slope angles of gullies in our study area consistently reflect the inherited slope angles of the host escarpment, suggesting that traditional slope-based evidence of fluvial activity in martian gullies needs to be placed in context of its local environment. We also observed a direct relationship between gully morphology and local composition of surface units. Martian gully features, and possibly method of erosion appeared heavily influenced by changes in underlying geology and presence of erodible sediment. Examples included gully shape changing in accordance with type of erodible sediment. We suggest that the degraded rims of gully-free Noachian craters precluded slope angles high enough to trigger creation of precursors to alcoves through mass wasting. Lack of these hollows has probably prevented the accumulation of enough ice-rich sediment for gullies to form in. Our analysis reveals that there is a complex interdependence between slope processes and the local environment, and global martian gully models may not work at the local scale.

  11. Water on early Mars: Possible subaqueous sedimentary deposits covering ancient cratered terrain in western Arabia and Sinus Meridiani

    NASA Astrophysics Data System (ADS)

    Edgett, Kenneth S.; Parker, Timothy J.

    1997-11-01

    Western Arabia and northern Sinus Meridiani (30 deg N-10 deg S; 40 deg W-40 deg E) are almost entirely covered by wind-eroded, horizontally-bedded, sedimentary layers that lap against local topographic features. This portion of Mars' ancient cratered terrain is relatively low (less than 1 km elevation) and flat (sloping westward 0.7 m/km over 3,000 km). The region lacks valley network channels. We propose that at some time in early Martian history, this region was under water. The water hypothesis is strengthened by the presence of (1) a shore-like contact between smooth-surfaced deposits and ancient cratered terrain in central Sinus Meridiani, (2) polygonal structures in northern Sinus Meridiani, and (3) sand (which cannot be from airfall), possibly reworked by wind from the underlying sedimentary units. The September 1997 arrival of Mars Global Surveyor's thermal emission spectrometer offers an opportunity to begin to test this hypothesis by searching for carbonate and evaporite minerals among the sediment covering the region.

  12. Compositions of Low Albedo Intracrater Materials and Wind Streaks on Mars: Examination of MGS TES Data in Western Arabia Terra

    NASA Technical Reports Server (NTRS)

    Bandfield, J. L.; Wyatt, M. B.; Christensen, P.; McSween, H. Y., Jr.

    2001-01-01

    Basalt and andesite surface compositions are identified within individual low albedo intracrater features and adjacent dark wind streaks. High resolution mapping of compositional heterogeneities may help constrain origin hypotheses for these features. Additional information is contained in the original extended abstract.

  13. Terra Sirenum

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    This image is from a region called Terra Sirenum in Mars' southern hemisphere. This region was named in 1958 for the Sea of the Sirens from Greek Mythology. This is not a sea, however, but a relatively dusty, high albedo region of Mars. There are numerous dust devil tracks that are apparent in the center- left of the image. The dust devils act like vacuum cleaners and lift dust off of the surface leaving a less dusty and relatively lower albedo surface behind. Dust devils are very common on Mars and are thought to be the primary mechanism for constantly lifting the dust into the atmosphere. Dust is constantly present in the Martian atmosphere in greater abundances than typically seen on Earth. The Martian dust is one of the main factors that affect the present Martian climate and clearly displays the relationship between Mars' geology and atmosphere.

    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

  14. Related magma-ice interactions: Possible origins of chasmata, chaos, and surface materials in Xanthe, Margaritifer, Meridiani Terrae, Mars

    USGS Publications Warehouse

    Chapman, M.G.; Tanaka, K.L.

    2002-01-01

    We examine here the close spatial and temporal associations among several unique features of Xanthe and Margaritifer Terrae, specifically the Valles Marineris troughs or chasmata and their interior deposits, chaotic terrain, the circum-Chryse outflow channels, and the subdued cratered material that covers Xanthe, Margaritifer, and Meridiani Terrae. Though previous hypotheses have attempted to explain the origin of individual features or subsets of these, we suggest that they may all be related. All of these features taken together present a consistent scenario that includes the processes of sub-ice volcanism and other magma/ice interactions, results of intrusive events during Late Noachian to Early Amazonian times. ?? 2002 Elsevier Science (USA).

  15. Geology of Libya Montes and the Interbasin Plains of Northern Tyrrhena Terra, Mars: First Year Results and Second Year Work Plan

    NASA Technical Reports Server (NTRS)

    Skinner, J. A., Jr.; Rogers, A. D.; Seelos, K. D.

    2010-01-01

    The Libya Montes-Tyrrhena Terra highland-lowland transitional zone of Mars is a complex tectonic and erosional region that contains some of the oldest exposed materials on the Martian surface as well as aqueous mineral signatures that may be potential chemical artifacts of early highland formational processes. Our 1:1M scale mapping project includes the geologic materials and landforms contained within MTMs 00282, -05282, -10282, 00277, - 05277, and -10277, which cover the highland portion of the transitional zone. The map region extends from the Libya Montes southward into Tyrrhena Terra and to the northern rim of Hellas basin and includes volcanic rocks of Syrtis Major Planum and a broad lowlying plain (palus) that forms a topographic divide between Isidis and Hellas basins. The objective of this project is to describe the geologic history of regional massif and plains materials by combining geomorphological and compositional mapping observations. This abstract summarizes the technical approaches and interim scientific results of Year 1 efforts and the expected work plan for Year 2 efforts.

  16. Terra Meridiani

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site] (Released 28 June 2002) The Science This THEMIS visible image illustrates the complex terrains within Terra Meridiani. This general region is one of the more complex on Mars, with a rich array of sedimentary, volcanic, and impact surfaces that span a wide range of martian history. This image lies at the eastern edge of a unique geologic unit that was discovered by the Mars Global Surveyor Thermal Emission Spectrometer (TES) Science Team to have high concentrations of a unique mineral called grey (crystalline) hematite. As discussed by the TES Science Team, this mineral typically forms by processes associated with water, and this region appears to have undergone alteration by hydrothermal (hot water) or other water-related processes. As a result of this evidence for water activity, this region is a leading candidate for further exploration by one of NASA's upcoming Mars Exploration Rovers. The brightness and texture of the surface varies remarkably throughout this image. These differences are associated with different rock layers or ?units?, and can be used to map the occurrence of these layers. The number of layers indicates that extensive deposition by volcanic and sedimentary processes has occurred in this region. Since that time, however, extensive erosion has occurred to produce the patchwork of different layers exposed across the surface. Several distinct layers can be seen within the 20 km diameter crater at the bottom (south) of the image, indicating that this crater once contained layers of sedimentary material that has since been removed. THEMIS infrared images of this region show that many of these rock layers have distinctly different temperatures, indicating that the physical properties vary from layer to layer. These differences suggest that the environment and the conditions under which these layers were deposited or solidified varied through time as these layers were formed. The Story Mars exploration

  17. Terra Sirenum Slope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    16 July 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the layered rocks and boulders exposed on the wall of a trough in the Terra Sirenum region. The layers that erode to produce large boulders are harder and more resistant to weathering and erosion than those that do not. The slope is located near 25.8oS, 139.8oW. The image covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the upper left.

  18. Lunar and Planetary Science XXXV: Impacts on Mars and Earth

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Impacts on Mars and Earth" included the following reports:A Timescale for Major Events in Early Mars Crustal Evolution; Impact Craters in Arabia Terra, Mars; Ancient Giant Basin/Aquifer System in the Arabia Region, Mars; Small Crater Morphology Within Gusev Crater and Isidis Planitia: Evidence for Widespread Secondaries on Mars; Martian Surface Properties: Inferences from Resolved Differences in Crater Geometries; Asymmetric Ramparts of Secondary Craters in Cerberus, Mars: Interpretation and Implications for Local Stratigraphy; Depth to Diameter Relationships of Craters in the High Latitudes (70 -80 ) of Mars: Implications for Geologic History of Those Areas; Impact Cratering on Mars: Search for Target Influence on Morphology; Starting Conditions for Hydrothermal Systems Underneath Martian Craters: Hydrocode Modeling; Impact-induced Hydrothermal System at the Sudbury Crater: Duration, Temperatures, Mechanics, and Biological Implications; Major and Trace Element Variations in Impact Crater Clay from Chicxulub, Lonar, and Mistastin, Implications for the Martian Soil; Stable Isotopes and Hydrothermal Fluid Source in the Yaxcopoil-1 Borehole, Chicxulub Impact Structure, Mexico; and Chicxulub Impact Melts: Geochemical Signatures of Target Lithology Mixing and Post-Impact Hydrothermal Fluid Processes.

  19. Terra Satellite

    Atmospheric Science Data Center

    2013-04-19

    ... techniques, this enables construction of 3-D models and estimation of the total amount of sunlight reflected by Earth's diverse ... Artist Concept Terra with MISR location:  Global Images thumbnail:  ...

  20. Regional-scale stratigraphy of surface units in Tyrrhena and Iapygia Terrae, Mars: Insights into highland crustal evolution and alteration history

    USGS Publications Warehouse

    Rogers, A.D.; Fergason, R.L.

    2011-01-01

    The compositional, thermophysical and geologic characteristics of surface units in Iapygia and Tyrrhena Terra (60??E-100??E, 0??-30??S) provide new insights into the compositional stratigraphy of the region. Intercrater plains are dominated by two surface units. The older unit (unit 1) is deficient in olivine and more degraded and likely consists of a mixture of impact, volcanic and sedimentary materials. The younger unit (unit 2) is enriched in olivine, exhibits a resistant morphology and higher thermal inertia, and likely represents volcanic infilling of plains. Units 1 and 2 bear a strong resemblance to those previously mapped in Mare Serpentis, a section of highlands crust located northwest of Hellas Basin. Thus, the two major intercrater plains units are even more widespread than previously thought and therefore likely constitute important components of Mars' highland stratigraphy. Many craters in the region contain high thermal inertia deposits (unit 3) that are compositionally identical to unit 2. These may have formed via volcanic infilling or may represent sedimentary materials that have been eroded from crater walls and lithified. Less common units include olivine and/or pyroxene-rich massifs and crater central peaks. These are primarily found within Hellas Basin rim units and may represent mantle materials brought toward the surface during the Hellas impact. Putative chloride deposits are primarily associated with olivine-deficient surfaces (unit 1) that may be heavily degraded occurrences of unit 2. The observations raise a variety of questions related to Martian crustal evolution and alteration that may have more widespread implications outside the study region. Copyright ?? 2011 by the American Geophysical Union.

  1. Regional-scale stratigraphy of surface units in Tyrrhena and Iapygia Terrae, Mars: insights into highland crustal evolution and alteration history

    USGS Publications Warehouse

    Rogers, A. Deanne; Fergason, Robin L.

    2011-01-01

    The compositional, thermophysical and geologic characteristics of surface units in Iapygia and Tyrrhena Terra (60°E-100°E, 0°-30°S) provide new insights into the compositional stratigraphy of the region. Intercrater plains are dominated by two surface units. The older unit (unit 1) is deficient in olivine and more degraded and likely consists of a mixture of impact, volcanic and sedimentary materials. The younger unit (unit 2) is enriched in olivine, exhibits a resistant morphology and higher thermal inertia, and likely represents volcanic infilling of plains. Units 1 and 2 bear a strong resemblance to those previously mapped in Mare Serpentis, a section of highlands crust located northwest of Hellas Basin. Thus, the two major intercrater plains units are even more widespread than previously thought and therefore likely constitute important components of Mars' highland stratigraphy. Many craters in the region contain high thermal inertia deposits (unit 3) that are compositionally identical to unit 2. These may have formed via volcanic infilling or may represent sedimentary materials that have been eroded from crater walls and lithified. Less common units include olivine and/or pyroxene-rich massifs and crater central peaks. These are primarily found within Hellas Basin rim units and may represent mantle materials brought toward the surface during the Hellas impact. Putative chloride deposits are primarily associated with olivine-deficient surfaces (unit 1) that may be heavily degraded occurrences of unit 2. The observations raise a variety of questions related to Martian crustal evolution and alteration that may have more widespread implications outside the study region.

  2. Nature and origin of materials exposed in the Oxia Palus-Western Arabia-Sinus Meridiani region, Mars

    NASA Technical Reports Server (NTRS)

    Presley, M. A.; Arvidson, R. E.

    1988-01-01

    Images and thermal data obtained by the Viking Orbiter over the Martian equatorial cratered terrain in western Arabia, eastern Oxia, and Sinuses Sabaeus and Meridiani, have been evaluated with a view to the identification, characterization, and mapping of local, bedrock-related materials. Three primary color/thermal units are discernible: (1) bright red dust storm deposits; (2) brown materials, which may be indurated; and (3) dark, but less red materials which may be composed of medium sand size-range lithic fragments. The surficial units exposed over the study area are judged to represent mixed eolian deposits, largely decoupled from the bedrock underneath.

  3. CD-ROM publication of the Mars digital cartographic data base

    NASA Technical Reports Server (NTRS)

    Batson, R. M.; Eliason, E. M.; Soderblom, L. A.; Edwards, Kathleen; Wu, Sherman S. C.

    1991-01-01

    The recently completed Mars mosaicked digital image model (MDIM) and the soon-to-be-completed Mars digital terrain model (DTM) are being transcribed to optical disks to simplify distribution to planetary investigators. These models, completed in FY 1991, provide a cartographic base to which all existing Mars data can be registered. The digital image map of Mars is a cartographic extension of a set of compact disk read-only memory (CD-ROM) volumes containing individual Viking Orbiter images now being released. The data in these volumes are pristine in the sense that they were processed only to the extent required to view them as images. They contain the artifacts and the radiometric, geometric, and photometric characteristics of the raw data transmitted by the spacecraft. This new set of volumes, on the other hand, contains cartographic compilations made by processing the raw images to reduce radiometric and geometric distortions and to form geodetically controlled MDIM's. It also contains digitized versions of an airbrushed map of Mars as well as a listing of all feature names approved by the International Astronomical Union. In addition, special geodetic and photogrammetric processing has been performed to derive rasters of topographic data, or DTM's. The latter have a format similar to that of MDIM, except that elevation values are used in the array instead of image brightness values. The set consists of seven volumes: (1) Vastitas Borealis Region of Mars; (2) Xanthe Terra of Mars; (3) Amazonis Planitia Region of Mars; (4) Elysium Planitia Region of Mars; (5) Arabia Terra of Mars; (6) Planum Australe Region of Mars; and (7) a digital topographic map of Mars.

  4. Quasi-periodic bedding in the sedimentary rock record of mars

    USGS Publications Warehouse

    Lewis, K.W.; Aharonson, O.; Grotzinger, J.P.; Kirk, R.L.; McEwen, A.S.; Suer, T.-A.

    2008-01-01

    Widespread sedimentary rocks on Mars preserve evidence of surface conditions different from the modern cold and dry environment, although it is unknown how long conditions favorable to deposition persisted. We used 1-meter stereo topographic maps to demonstrate the presence of rhythmic bedding at several outcrops in the Arabia Terra region. Repeating beds are ???10 meters thick, and one site contains hundreds of meters of strata bundled into larger units at a ???10:1 thickness ratio. This repetition likely points to cyclicity in environmental conditions, possibly as a result of astronomical forcing. If deposition were forced by orbital variation, the rocks may have been deposited over tens of millions of years.

  5. Urbanization: Riyadh, Saudi Arabia

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Riyadh, the national capital of Saudi Arabia, is shown in 1972, 1990 and 2000. Its population grew in these years from about a half million to more than two million. Saudi Arabia experienced urbanization later than many other countries; in the early 1970s its urban-rural ratio was still about 1:3. By 1990 that had reversed to about 3:1. The city grew through in-migration from rural areas, and from decreases in the death rate while birthrates remained high. The 1972 image is a Landsat MSS scene; the 1990 image is a Landsat Thematic Mapper scene; and the 2000 image is an ASTER scene. All three images cover an area of about 27 x 34 km. The image is centered at 24.6 degrees north latitude, 46.6 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  6. Terra Cimmeria Crater Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The landslide in this VIS image is located inside an impact crater in the Terra Cimmeria region of Mars. The unnamed crater hosting this image is just east of Molesworth Crater.

    Image information: VIS instrument. Latitude -27.7, Longitude 152 East (208 West). 19 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.

  7. InfoTerra/TerraSAR initiative

    NASA Astrophysics Data System (ADS)

    Wahl, Manfred W.

    2004-01-01

    The overarching goal of the InfoTerra/TerraSAR Initiative is to establish a self-sustaining operational/commercial business built on Europe"s know-how and experience in space-borne Synthetic Aperture Radar (SAR) technology, in SAR data processing as well as in SAR applications. InfoTerra stands for a new business concept based on supplying innovative geo-information products and services. TerraSAR is a space and ground system conceived to consist of an initial deployment and operation of 2 Radar satellites (one in X- and one in L-band) flying in a tandem configuration in the same orbit. The design of TerraSAR is driven by the market and is user-oriented. TerraSAR is key to capturing a significant proportion of the existing market and to opening new market opportunities, when it becomes operational. The InfoTerra/TerraSAR Initiative has evolved gradually. It started in 1997 as a joint venture between German (DSS) and British (MMS-UK) space industry, strongly supported by both space agencies, DLR and BNSC. In early 2001, DLR and BNSC submitted to ESA the Formal Programme Proposal for InfoTerra/TerraSAR to become an essential element of ESA"s Earth Watch Programme. In summer 2001, when it became evident that there was not yet sufficient support from the ESA Member States to allow immediate start entering into TerraSAR Phase C/D, it has been decided to implement first a TerraSAR consolidation phase. In early 2002, in order to avoid further delays, a contract was signed between DLR and Astrium GmbH on the development of one component of TerraSAR, the TerraSAR-X, in the frame of a national programme, governed by a Public Private Partnership Agreement. Even if now the different launch dates for TerraSAR-X and TerraSAR-L are narrowing down the window of common data acquisition, it is a reasonable starting point, but it should always be kept in mind that the utmost goal for the longterm is to achieve self sustainability by supplying geo-information products and services

  8. Mars

    NASA Astrophysics Data System (ADS)

    McSween, H. Y., Jr.

    2003-12-01

    More than any other planet, Mars has captured our attention and fueled our speculations. Much of this interest relates to the possibility of martian life, as championed by Percival Lowell in the last century and subsequently in scientific papers and science fiction. Lowell's argument for life on Mars was based partly on geochemistry, in that his assessmentof the planet's hospitable climate was dependent on the identification of H2O ice rather than frozen CO2 in the polar caps. Although this reasoning was refuted by Alfred Wallace in 1907, widespread belief in extant martian life persisted within the scientific community until the mid-twentieth century (Zahnle, 2001). In 1965 the Mariner 4 spacecraft flyby suddenly chilled this climate, by demonstrating that the martian atmosphere was thin and the surface was a cratered moonscape devoid of canals. This view of Mars was overturned again in 1971, when the Mariner 9 spacecraft discovered towering volcanoes and dry riverbeds, implying a complex geologic history. The first geochemical measurements on Mars, made by two Viking landers in 1976, revealed soils enriched in salts suggesting exposure to water, but lacking organic compounds which virtually ended discussion of martian life.The suggestion that a small group of achondritic meteorites were martian samples (McSween and Stolper, 1979; Walker et al., 1979; Wasson and Wetherill, 1979) found widespread acceptance when trapped gases in them were demonstrated to be compositionally similar to the Mars atmosphere ( Bogard and Johnson, 1983; Becker and Pepin, 1984). The ability to perform laboratory measurements of elements and isotopes present in trace quantities in meteorites has invigorated the subject of martian geochemistry. Indeed, because of these samples, we now know more about the geochemistry of Mars than of any other planet beyond the Earth-Moon system. Some studies of martian meteorites have prompted a renewed search for extraterrestrial life using chemical

  9. Evolution of Lacustrine Environments on Mars and Their Significance: The Case for the Brazos Lakes and East Terra Meridiani Basins as Landing Sites for Surveyor 2001

    NASA Astrophysics Data System (ADS)

    Cabrol, N. A.; Grin, E. A.

    1999-01-01

    Ancient Martian lacustrine environments must be considered as primary targets to explore on Mars. Terrestrial studies show that lakes are exceptional sites to keep the record of the evolution of climate, geology, water and life. Finding this record is also the principal objective of the Mars Surveyor Program. This record encompasses changes at local, regional and global scales. Lacustrine sediments provide critical information about all events occurring in the lake catchment area. They are also a locus of complex chemical processes, concentration for life and favorable sites for fossilization processes to take place. We proposed two candidate-sites in the Schiaparelli Crater region responding to this high-priority scientific objective at the June 1999 meeting in Buffalo, NY. The two sites are located in the Sinus Sabeus quadrangle, are well documented by MOC images, and are among the best evidence yet of a Martian past lacustrine activity. We develop their case as high-priority sites for the 01' mission.

  10. Rippled Mars

    NASA Technical Reports Server (NTRS)

    2004-01-01

    29 July 2004 Hundreds of large ripples or small dunes cover the landscape in the Terra Tyrrhena region of Mars in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image. The winds responsible for these dunes blew from the north-northwest (top/upper left). This scene is located near 8.8oS, 252.8oW, and covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the terrain from the left.

  11. Exobiology site priorities for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Farmer, Jack D.; Desmarais, David J.

    1994-01-01

    The fact that life developed on the Earth within the first billion years of its history makes it quite plausible that life may have also developed on Mars. If life did develop on Mars, it undoubtedly left behind a fossil record. Such a fossil record is likely to be more accessible than either subsurface environments that may harbor life, or scattered 'oases' that may be present at the surface. Consequently, the post-Viking approach of Mars exobiology has shifted focus to search for evidence of an ancient martian biosphere. This has led to the emergence of a new subdiscipline of paleontology, herein termed 'exopaleontology', which deals with the exploration for fossils on other planets and whose core concepts derive from Earth-based Precambrian paleontology, microbial ecology, and sedimentology. Potential targets on Mars for subaqueous spring deposits, sedimentary cements, and evaporites are ancient terminal lake basins where hydrological systems could have endured for some time under arid conditions. Potential targets for the Mars Pathfinder mission include channeled impact craters and areas of deranged drainage associated with outflows in northwest Arabia and Xanthe Terra, where water may have ponded temporarily to form lakes. The major uncertainty of such targets is their comparatively younger age and the potentially short duration of hydrological activity compared to older paleolake basins found in the southern hemisphere. However, it has been suggested that cycles of catastrophic flooding associated with Tharsis volcanism may have sustained a large body of water, Oceanus Borealis, in the northern plains area until quite late in martian history. Although problematic, the shoreline areas of the proposed northern ocean provide potential targets for a Mars Pathfinder mission aimed at exploring for carbonates or other potentially fossiliferous marine deposits. Carbonates and evaporites possess characteristic spectra signatures in the near-infrared and should be

  12. Saudi Arabia.

    PubMed

    1986-12-01

    In 1985, Saudi Arabia's population stood at 9.6 million, with an annual growth rate of 2.8%. The infant mortality rate was 78/1000 and life expectancy was 60 years. Literacy was at the 50% level among men and 25% among women. Of the work force of 3 million, 66% are foreign workers. The labor force is distributed as follows: agriculture, 14%; industry, 11%; services, commerce, and government, 53%; construction, 20%; and oil and mining, 2%. The GDP was US$98.1 billion in 1985-86, with an annual growth rate of 8% and a per capita GDP of $9800. Under the impact of rapid economic growth, urbanization has advanced rapidly and 95% of the population is now settled. Saudi Arabia, a monarchy, is divided into 14 provinces that are governed by princes or relatives of the royal family. Oil is the major source of foreign exchange, contributing 81% of government revenues. Ample government funds and foreign exchange resources are available for development, defense, and aid to other Arab and Islamic countries. The government has sought to allocate its petroleum income to transform its relatively undeveloped oil-based economy into that of a modern industrial state while maintaining traditional Islamic values. The standard of living of most Saudis has improved significantly. A shortage of skilled workers at all levels remains the principal obstacle to rapid development. PMID:12178138

  13. Nature and origin of the hematite-bearing plains of Terra Meridiani based on analyses of orbital and Mars Exploration rover data sets

    USGS Publications Warehouse

    Arvidson, R. E.; Poulet, F.; Morris, R.V.; Bibring, J.-P.; Bell, J.F., III; Squyres, S. W.; Christensen, P.R.; Bellucci, G.; Gondet, B.; Ehlmann, B.L.; Farrand, W. H.; Fergason, R.L.; Golombeck, M.; Griffes, J.L.; Grotzinger, J.; Guinness, E.A.; Herkenhoff, K. E.; Johnson, J. R.; Klingelhofer, G.; Langevin, Y.; Ming, D.; Seelos, K.; Sullivan, R.J.; Ward, J.G.; Wiseman, S.M.; Wolff, M.J.

    2006-01-01

    The ???5 km of traverses and observations completed by the Opportunity rover from Endurance crater to the Fruitbasket outcrop show that the Meridiani plains consist of sulfate-rich sedimentary rocks that are largely covered by poorly-sorted basaltic aeolian sands and a lag of granule-sized hematitic concretions. Orbital reflectance spectra obtained by Mars Express OMEGA over this region are dominated by pyroxene, plagioclase feldspar, crystalline hematite (i.e., concretions), and nano-phase iron oxide dust signatures, consistent with Pancam and Mini-TES observations. Mo??ssbauer Spectrometer observations indicate more olivine than observed with the other instruments, consistent with preferential optical obscuration of olivine features in mixtures with pyroxene and dust. Orbital data covering bright plains located several kilometers to the south of the landing site expose a smaller areal abundance of hematite, more dust, and a larger areal extent of outcrop compared to plains proximal to the landing site. Low-albedo, low-thermal-inertia, windswept plains located several hundred kilometers to the south of the landing site are predicted from OMEGA data to have more hematite and fine-grained olivine grains exposed as compared to the landing site. Low calcium pyroxene dominates spectral signatures from the cratered highlands to the south of Opportunity. A regional-scale model is presented for the formation of the plains explored by Opportunity, based on a rising ground water table late in the Noachian Era that trapped and altered local materials and aeolian basaltic sands. Cessation of this aqueous process led to dominance of aeolian processes and formation of the current configuration of the plains. Copyright 2006 by the American Geophysical Union.

  14. Sand Dunes in Noachis Terra

    NASA Technical Reports Server (NTRS)

    2004-01-01

    11 February 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-toned sand dunes in a crater in eastern Noachis Terra. Most big martian dunes tend to be dark, as opposed to the more familiar light-toned dunes of Earth. This difference is a product of the composition of the dunes; on Earth, most dunes contain abundant quartz. Quartz is usually clear (transparent), though quartz sand grains that have been kicked around by wind usually develop a white, frosty surface. On Mars, the sand is mostly made up of the darker minerals that comprise iron- and magnesium-rich volcanic rocks--i.e., like the black sand beaches found on volcanic islands like Hawaii. Examples of dark sand dunes on Earth are found in central Washington state and Iceland, among other places. This picture is located near 49.0oS, 326.3oW. Sunlight illuminates this scene from the upper left; the image covers an area 3 km (1.9 mi) wide.

  15. Medusae Fossae-Elysium Region, Mars: Depression in the HEND/Odyssey Map of Mars Epithermal Neutrons

    NASA Technical Reports Server (NTRS)

    Ivanov, M. A.; Litvak, M. L.; Mitrofanov, I. G.; Boynton, W.; Saunders, R. S.

    2003-01-01

    The first data from the Gamma Ray Spectrometer (GRS) onboard Mars Odyssey spacecraft showed that the low neutron fluxes characterize both subpolar regions of Mars. The low neutron fluxes mean the presence of hydrogen-rich soils and have been interpreted as an indication on abundant water ice in these areas. The equatorial region of Mars (equatorward of approx. 50 deg) is characterized by higher fluxes of both epithermal (0.4 eV-100 keV, come from depth 1-2 m) and fast (3.4-7.3 MeV, come from depth 0.2-0.3 m) neutrons meaning that this area is mostly dry. The pattern of distribution of the neutron fluxes is in a good agreement with the theoretical predictions on the stability of ground ice on present Mars. The actual distribution of the ice, however, depends on variations of thermal inertia of soils and albedo of the surface. The flux of the epithermal neutrons detected by the HEND instrument, which is part of GRS, has two noticeable depressions in the equatorial region, one in Arabia Terra and another in the Medusae Fossae-Elysium region (MFER). Here we present the initial results of analysis of characteristics of the neutron fluxes and regional geological setting of the epithermal neutron depression in this area. The main goal of our study was to put some constraints on the time of the anomaly formation and to assess possible form of hydrogen (ground ice vs. chemically bound water) there.

  16. NASA Remote Sensing Validation Data: Saudi Arabia

    DOE Data Explorer

    Myers, Daryl R. [NREL; Al-Abbadi, Naif [King Abdulaziz City for Science and Technology, Energy Research Institite; Wilcox, Steve [NREL

    Since 1995, the King Abdulaziz City for Science and Technology (KACST) and the National Renewable Energy Laboratory (NREL) have co-operated to establish a 12 station network of high quality solar radiation monitoring installations across the Kingdom of Saudi Arabia. NREL and KACST realized the value of accurate surface solar radiation flux measurements for validation of satellite derived surface and atmospheric solar radiation flux measurements, and is making this data available to support validation of satellite data products related to the NASA Mission to Planet Earth component of the Earth Science Enterprise Earth Observing System (EOS) project to evaluate long term climate trends based on measuements from EOS Terra Platforms. A CIMEL 8 channel sunphotometer for measuring aerosol optical depth at 6 wavelengths and total column water has been deployed at the Solar Village station since February 24, 1999. [Taken from http://rredc.nrel.gov/solar/new_data/Saudi_Arabia/

  17. EOS Terra Validation Program

    NASA Technical Reports Server (NTRS)

    Starr, David

    1999-01-01

    The EOS Terra mission will be launched in July 1999. This mission has great relevance to the atmospheric radiation community and global change issues. Terra instruments include ASTER, CERES, MISR, MODIS and MOPITT. In addition to the fundamental radiance data sets, numerous global science data products will be generated, including various Earth radiation budget, cloud and aerosol parameters, as well as land surface, terrestrial ecology, ocean color, and atmospheric chemistry parameters. Significant investments have been made in on-board calibration to ensure the quality of the radiance observations. A key component of the Terra mission is the validation of the science data products. This is essential for a mission focused on global change issues and the underlying processes. The Terra algorithms have been subject to extensive pre-launch testing with field data whenever possible. Intensive efforts will be made to validate the Terra data products after launch. These include validation of instrument calibration (vicarious calibration) experiments, instrument and cross-platform comparisons, routine collection of high quality correlative data from ground-based networks, such as AERONET, and intensive sites, such as the SGP ARM site, as well as a variety field experiments, cruises, etc. Airborne simulator instruments have been developed for the field experiment and underflight activities including the MODIS Airborne Simulator (MAS), AirMISR, MASTER (MODIS-ASTER), and MOPITT-A. All are integrated on the NASA ER-2, though low altitude platforms are more typically used for MASTER. MATR is an additional sensor used for MOPITT algorithm development and validation. The intensive validation activities planned for the first year of the Terra mission will be described with emphasis on derived geophysical parameters of most relevance to the atmospheric radiation community. Detailed information about the EOS Terra validation Program can be found on the EOS Validation program

  18. EOS Terra Validation Program

    NASA Technical Reports Server (NTRS)

    Starr, David

    2000-01-01

    The EOS Terra mission will be launched in July 1999. This mission has great relevance to the atmospheric radiation community and global change issues. Terra instruments include Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Clouds and Earth's Radiant Energy System (CERES), Multi-Angle Imaging Spectroradiometer (MISR), Moderate Resolution Imaging Spectroradiometer (MODIS) and Measurements of Pollution in the Troposphere (MOPITT). In addition to the fundamental radiance data sets, numerous global science data products will be generated, including various Earth radiation budget, cloud and aerosol parameters, as well as land surface, terrestrial ecology, ocean color, and atmospheric chemistry parameters. Significant investments have been made in on-board calibration to ensure the quality of the radiance observations. A key component of the Terra mission is the validation of the science data products. This is essential for a mission focused on global change issues and the underlying processes. The Terra algorithms have been subject to extensive pre-launch testing with field data whenever possible. Intensive efforts will be made to validate the Terra data products after launch. These include validation of instrument calibration (vicarious calibration) experiments, instrument and cross-platform comparisons, routine collection of high quality correlative data from ground-based networks, such as AERONET, and intensive sites, such as the SGP ARM site, as well as a variety field experiments, cruises, etc. Airborne simulator instruments have been developed for the field experiment and underflight activities including the MODIS Airborne Simulator (MAS) AirMISR, MASTER (MODIS-ASTER), and MOPITT-A. All are integrated on the NASA ER-2 though low altitude platforms are more typically used for MASTER. MATR is an additional sensor used for MOPITT algorithm development and validation. The intensive validation activities planned for the first year of the Terra

  19. Plains Style Caldera Complexes: Evidence for Ancient, Explosive Volcanism on Mars

    NASA Astrophysics Data System (ADS)

    Michalski, J. R.; Bleacher, J. E.

    2014-12-01

    One of the mysteries of Mars' geology is the origin of widespread, layered, friable deposits that likely formed through air fall deposition. The enigmatic chaos terrains are largely composed of such deposits, as are many of the most intriguing layered, clay- and sulfate-bearing deposits of astrobiological interest. Such deposits are most likely of volcanic origin, but lack an obvious source, based on comparison with well-known volcanic provinces [1]. We suggest that these deposits may have been sourced from previously unrecognized explosive volcanoes in Arabia Terra. While Arabia is not traditionally considered to be a volcanic region, we propose that several of the large depressions in the area are in fact calderas that formed through a combination of structural collapse and explosive volcanism. These features are characterized by the observation of sets of nested depressions, association with ridged plains, development of ring fractures and faults, the presence of interior slump blocks, and direct association, in some cases, with friable deposits, lavas and evidence for lava lakes. Eden Patera is the type example and shows evidence for three nested calderas with >4000 km3 of collapse volume. Siloe Patera also contains a set of nested collapse features that occur within a zone of demagnetized crust that might indicate the presence of a magma chamber at shallow depth [2]. It is not yet clear why explosive volcanoes may have formed in Arabia Terra, but we suggest that they might represent the rapid rise of mafic magmas through a thin crust. They might represent more silicic or volatile-rich magmas, but these scenarios do not appear to be necessary [3]. We suggest that explosive mafic volcanism was an important aspect of early Martian geological processes. [1] Kerber, L., Head III, J., Madeleine, J. B., Forget, F. & Wilson, L. The dispersal of pyroclasts from ancient explosive volcanoes on Mars: Implications for the friable layered deposits. Icarus 219, 358-381 (2012

  20. Xanthe Terra Landslide in IR

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    This is a daytime IR image of a chaos region within Xanthe Terra. As with earlier images, the landslide in this image is caused by the failure of steep slopes releasing material to form the landslide deposit.

    Image information: IR instrument. Latitude 3.1, Longitude 309.7 East (50.3 West). 100 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.

  1. Can hydrous minerals account for the observed mid-latitude water on Mars?

    SciTech Connect

    Bish, D. L.; Vaniman, D. T.; Fialips, C. I.; Carey, J. W.; Feldman, W. C.

    2003-01-01

    Great interest was generated with the discovery by the Odyssey spacecraft OC heterogeneously distributed hydrogcn at martian mid-latitudes, suggesting that large areas of the near-equatorial highlands contain near-surface deposits of 'chemically and/or physically bound 1120 and/or OH' in amounts up to 3.8% equivalent H20. More recent interpretations of the Odyssey data using new calibrations suggest that some near-equatorial areas, such as Arabia Terra, contain up to 8.5f I .3% water-equivalent hydrogen. Such shallow occurrences (Mars, and both groups of minerals are common terrestrial alteration products of hydrovolcanic basaltic ashes and palagonitic material comparable io those that may be widespread on Mars. Smectites within martian meteorites, attributed to hydrous alteration on Mars rather than on Earth, provide direct evidence of clay minerals from Mars. In addition, new thermal emission spectrometer (TES) data provide evidence for unspecified zeolites in martian surface dust, and concluded that spectral deconvolution of MGS TES and Mariner 9 IRIS data is consistent with the presence of zeolite in the martian surface dust.

  2. Resurfacing history of Tempe Terra and surroundings

    SciTech Connect

    Frey, H.V. ); Grant, T.D. )

    1990-08-30

    The resurfacing history of the Tempe Terra region is determined using the Neukum and Hiller technique of breaking cumulative frequency curves into separate branches where the curves depart from a standard production curve. We find four surfaces recorded in the heavily cratered portions of Tempe Terra, with crater retention ages N(1) = (242,100), (95,700), (20,800), and (5,500). This is interpreted to indicate three major resurfacing events occurred in this region, ending at N(1) = (95,700), (20,800), and (5,500). The ridged plains on the Tempe Terra plateau have an oldest recorded surface age of (20,400), identical to that of the second resurfacing event recorded in the heavily cratered areas. A single resurfacing of the ridged plains (which may have been a second episode of ridged plains volcanism) occurred at N(1) = (7,800). The knobby plains to the north west and east of Tempe Terra also show a resurfacing at (20,000) and additional events at (5,400) and perhaps (1,600). Mottled plains to the northeast record surfaces with crater retention age (7,500), (5,000), and (3,900), where the first age is determined by a single surviving crater. It appears that the Lunae Planum Age (LPA) (at N(1) = (20,000)) resurfacing event seen elsewhere on mars was widespread and effective in this region. A second widespread event appears to have ended at N(1) = (5,000). The authors estimate the thickness of the resurfacing materials corresponding to the LPA event to be less than 90 m in the heavily cratered areas but 300-500 m in the ridged plains themselves. Later resurfacing materials were generally thicker farther north in the mottled plains (300 m) than in the knobby plains (200 m).

  3. Cratered terrain in Terra Meridiani

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 30 April 2002) The Science This THEMIS visible image shows a region in Terra Meridiani near -12o S, 358o W (2o E). An old, heavily degraded channel can be seen from the lower (southern) portion of the image toward the top. This channel appears to terminate abruptly at the rim of a 10 km diameter crater. This apparent 'superposition' of the crater on top of the channel suggests that the impact crater was created after the channel was formed. This crater has two 3-km sized blocks of material that have slumped off from the lower left segment of the original crater rim. These immense blocks must have moved as a single unit because the rock layers that can be seen in the original wall of the crater can still be seen in these detached blocks. The walls of several craters in this image show vague hints of possible gully formation at the bottom of pronounced rock layers, with the suggestion of alcoves above the individual gullies. Well-developed gullies that were imaged by the Mars Orbiter Camera (MOC) on Mars Global Surveyor have been suggested to form by seepage and runoff of a fluid. The MOC has observed these gullies in numerous craters and channels further south, but they are uncommon at latitudes this close to the equator. Several sections of the crater walls appear to have ridges and troughs formed by the dry avalanche of loose rock, and a similar process of dry avalanche may account for the gullies seen in this THEMIS image. Patches of lighter material, possibly small dunes ripples, can be seen in several places throughout this image. The Story When the walls come tumbling down! Take a closer look at the bright linear ridges within a deep crater near the center of this image (bottom, left-hand side of the crater). Almost 2 miles long, these chunks of material slumped off the crater side in one fell swoop. Phoozhj! Down they came as one massive unit. You can tell, because the rock layers seen in the original wall of the crater are also still there in the

  4. Slope Streaks in Terra Sabaea

    NASA Technical Reports Server (NTRS)

    2007-01-01

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

    This HiRISE image shows the rim of a crater in the region of Terra Sabaea in the northern hemisphere of Mars.

    The subimage (figure 1) is a close-up view of the crater rim revealing dark and light-toned slope streaks. Slope streak formation is among the few known processes currently active on Mars. While their mechanism of formation and triggering is debated, they are most commonly believed to form by downslope movement of extremely dry sand or very fine-grained dust in an almost fluidlike manner (analogous to a terrestrial snow avalanche) exposing darker underlying material.

    Other ideas include the triggering of slope streak formation by possible concentrations of near-surface ice or scouring of the surface by running water from aquifers intercepting slope faces, spring discharge (perhaps brines), and/or hydrothermal activity.

    Several of the slope streaks in the subimage, particularly the three longest darker streaks, show evidence that downslope movement is being diverted around obstacles such as large boulders. Several streaks also appear to originate at boulders or clumps of rocky material.

    In general, the slope streaks do not have large deposits of displaced material at their downslope ends and do not run out onto the crater floor suggesting that they have little reserve kinetic energy. The darkest slope streaks are youngest and can be seen to cross cut and superpose older and lighter-toned streaks. The lighter-toned streaks are believed to be dark streaks that have lightened with time as new dust is deposited on their surface.

    Observation Geometry Image PSP_001808_1875 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 15-Dec-2006. The complete image is centered at 7.4 degrees latitude, 47.0 degrees East longitude. The range to the target site was 272.1 km

  5. Occurrence and origin of rhythmic sedimentary rocks on Mars

    NASA Astrophysics Data System (ADS)

    Lewis, Kevin W.; Aharonson, Oded

    2014-06-01

    Sedimentary rocks preserved on the surface of Mars represent a natural archive of past climate conditions. Although the details of their formation often remain poorly constrained, the recent detection of rhythmic bedding patterns in the Arabia Terra region suggests the influence of orbital variations on sedimentary deposition. Here we detail a number of new sites which exhibit quasiperiodic stratigraphic variations, demonstrating their occurrence throughout the equatorial region of the planet. We characterize these recorded signals as well as the local geomorphic context and structural attributes. Two cyclic units are identified within Gale crater, the landing site of the Mars Science Laboratory mission, enabling estimation of possible formation timescales for the geologic units that may be studied in situ by the rover. We find a general lack of fluvial features in connection with rhythmic geologic units, contrasting these sites with the aperiodic deltaic stratigraphy found at Eberswalde crater. Possible formation scenarios and their climatic implications are discussed for the diverse set of quasiperiodic sedimentary units. We propose multiple depositional pathways for recording cyclic climate changes, including repeated evaporitic precipitation from groundwater discharge in topographic lows as well as largely anhydrous accumulation of atmospheric dust for deposits outside of confined basins. The preservation of orbital signals in sediments distributed across a wide range of geographic settings suggests a pervasive influence on Martian climate conditions through time.

  6. Seasonal Frost in Terra Sirenum

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This image of the Terra Sirenum region of Mars was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 0918 UTC (4:18 a.m. EST) on Nov. 25, 2006, near 38.9 degrees south latitude, 195.9 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 18 meters (60 feet) across.

    At this time, Mars' southern hemisphere was experiencing mid-winter. During Martian southern winter, the southern polar cap is covered and surrounded by carbon dioxide frost and water frost. This is unlike Earth, whose frozen winter precipitation is made up of only one volatile -- water. The carbon dioxide frost evaporates, or sublimates, at a lower temperature than water frost. So, during spring, the carbon dioxide ice evaporates first and leaves a residue of water frost, which later sublimates as well.

    The image shown here covers part of a crater rim, which is illuminated from the upper left. North is at the top. The topography creates a cold microenvironment on the south side of the rim that is partially protected from solar illumination. That cold surface contains an outlier of the southern seasonal frost about 15 degrees of latitude closer to the equator than the average edge of the frost at this season.

    The top image was constructed from three infrared wavelengths that highlight the bluer color of frost than the background rock and soil. Note that the frost occurs both on sunlit and shaded surfaces on the south side of the rim. The shaded areas are still visible because they are illuminated indirectly by the Martian sky.

    The bottom image was constructed by measuring the depths of spectral absorption bands due to water frost and carbon dioxide frost, and displaying the results in image form. Blue shows strength of an absorption due to water frost near 1.50 micrometers, and green shows strength of an absorption due to carbon dioxide frost near 1.45 micrometers. Red shows

  7. Mars Digital Image Mosaic Globe

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The photomosaic that forms the base for this globe was created by merging two global digital image models (DIM's) of Mars-a medium-resolution monochrome mosaic processed to emphasize topographic features and a lower resolution color mosaic emphasizing color and albedo variations.

    The medium-resolution (1/256 or roughly 231 m/pixel) monochromatic image model was constructed from about 6,000 images having resolutions of 150-350 m/pixel and oblique illumination (Sun 20 o -45 o above the horizon). Radiometric processing was intended to suppress or remove the effects of albedo variations through the use of a high-pass divide filter, followed by photometric normalization so that the contrast of a given topographic slope would be approximately the same in all images.

    The global color mosaic was assembled at 1/64 or roughly 864 m/pixel from about 1,000 red- and green-filter images having 500-1,000 m/pixel resolution. These images were first mosaiced in groups, each taken on a single orbit of the Viking spacecraft. The orbit mosaics were then processed to remove spatially and temporally varying atmospheric haze in the overlap regions. After haze removal, the per-orbit mosaics were photometrically normalized to equalize the contrast of albedo features and mosaiced together with cosmetic seam removal. The medium-resolution DIM was used for geometric control of this color mosaic. A green-filter image was synthesized by weighted averaging of the red- and violet-filter mosaics. Finally, the product seen here was obtained by multiplying each color image by the medium-resolution monochrome image. The color balance selected for images in this map series was designed to be close to natural color for brighter, redder regions, such as Arabia Terra and the Tharsis region, but the data have been stretched so that the relatively dark regions appear darker and less red than they actually are.

    The images are presented in a projection that portrays the entire surface of Mars in a

  8. Small Volcano in Terra Cimmeria

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 26 June 2002) The Science This positive relief feature (see MOLA context) in the ancient highlands of Mars appears to be a heavily eroded volcanic center. The top of this feature appears to be under attack by the erosive forces of the martian wind. Light-toned streaks are visible, trending northeast to southwest, and may be caused by scouring of the terrain, or they may be dune forms moving sand. The northeast portion of the caldera area looks as though a layer of material is being removed to expose a slightly lighter-toned surface underneath. The flanks of this feature are slightly less cratered than the surrounding terrain, which could be explained in two ways: 1) this feature may be younger than the surrounding area, and has had less time to accumulate meteorite impacts, or 2) the slopes that are observed today may be so heavily eroded that the original, cratered surfaces are now gone, exposing relatively uncratered rocks. Although most of Terra Cimmeria has low albedo, some eastern portions, such as shown in this image, demonstrate an overall lack of contrast that attests to the presence of a layer of dust mantling the surface. This dust, in part, is responsible for the muted appearance and infill of many of the craters at the northern and southern ends of this image The Story This flat-topped volcano pops out from the surface, the swirls of its ancient lava flows running down onto the ancient highlands of Mars. Its smooth top appears to be under attack by the erosive forces of the martian wind. How can you tell? Click on the image above for a close-up look. You'll see some light-toned streaks that run in a northeast-southwest direction. They are caused either by the scouring of the terrain or dunes of moving sand. Either way, the wind likely plays upon the volcano's surface. Look also for the subtle, nearly crescent shaped feature at the northeast portion of the volcano's cap. It looks as if a layer of material has been removed by the wind, exposing

  9. Terra is in NORMAL Mode

    Atmospheric Science Data Center

    2016-02-23

    ... 22, 2016.  TERRA has recovered from Safe Hold and is now in Normal mode. CERES will hold their CAM Wednesday morning and will ... . You can learn more about this mission at the Terra web site. The Flight Operations Team is working on resolving the issue as ...

  10. A simple model of clastic sediments on Mars

    NASA Technical Reports Server (NTRS)

    Christensen, Philip R.; Malin, Michael C.

    1993-01-01

    In preparation for the start of Mars Observer operations at Mars later this year, Viking Infrared Thermal Mapper (IRTM) observations were synthesized into a simple but geologically coherent conceptual model for use in establishing targets for coordinated Thermal Emission Spectrometer (TES) and Mars Observer Camera (MOC) observations. The model is based on three assumptions that are, at best, only partly true: that albedo is a measure of the presence or absence of dust; that thermal inertia is a measure of the weighted average particle size; and that rock abundance is a measure of the statistical thickness of fine sediment (i.e., that the observed areal abundance of rock reflects the whole or partial burial of rocks). Using this model, it is possible to show that, on the scale of 30 km, mantles of wind-transportable sediment (dust and sand) are at most about 1 m thick, and that on a global average such mantles are about 35 cm thick. It is shown that 3.8 x 10(exp 19) cu cm of such sediment covers Mars equatorward of +/- 60 deg latitude. Using the model, interpretation of digital maps of IRTM data focus attention not only on areas where dust is the primary sediment (e.g., Arabia Terra), but also on areas where sand is the primary sediment (e.g., eastern Valles Marineris) and where rocks and other coarse materials are abundant (e.g., eastern Kasei Vallis). Three IRTM data sets are used in the analysis: Viking 1 and 2 pre-dawn observations mosaiced into a global map of single-point thermal inertias at 0.5 deg/bin resolution; Pleskot and Miner's global albedo map using the best available, clear-period IRTM observations (1x/bin); and Christensen's 1 deg/bin rock abundance map. Uncertainty analyses indicate these data sets to be accurate to 5 percent, 2 percent, and 20 percent, respectively.

  11. Northern Terra Meridiani's 'Monument Valley'

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Northern Terra Meridiani, near the intersection of the martian equator and prime meridian, is a region of vast exposures of layered rock. A thermal image from the Phobos 2 orbiter in 1989 showed these materials to be anomalously cool during the daytime, an observation very suggestive of dense, hardened materials like rock. Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images of this region show layered material exposed in cliffs, buttes, and mesas that in some ways resemble the rock outcrops of northern Arizona and southeastern Utah in North America (e.g., Monument Valley, Canyonlands, Zion National Park, Four Corners). MGS MOC Extended Mission operations have included several hundred opportunities for the spacecraft to be rolled off-nadir (i.e., at an angle other than 'straight down') to take pictures that repeat earlier MOC coverage. These repeat images, because they are taken from a different angle, can be combined with the original picture to produce a stereoscopic ('3-D') view. The image shown here is a composite of two pictures, the first taken October 23, 2000, the second acquired by pointing the spacecraft off-nadir on May 15, 2001. This view shows four buttes and a pinnacle (near left-center) composed of eroded, layered rock. The four buttes are each capped by the remains of a single layer of rock that is harder than the materials beneath it. It is the presence of this cap rock that has permitted these buttes to remain standing after surrounding materials were eroded away. Like the buttes of Monument Valley in the Navajo Nation on the Arizona/Utah border, these are believed to consist of sedimentary rocks, perhaps deposited in water or by wind, though some scientists have speculated that they could be made of thick accumulations of volcanic ash. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the left. To see the image in 3-D, red (left-eye) and blue (right-eye) '3-D' glasses are required.

  12. Lithostratigraphical analysis in northern Sinus Meridiani, Mars.

    NASA Astrophysics Data System (ADS)

    Baioni, D.; Sgavetti, M.; Tampella, G.; Wezel, F. C.

    2012-04-01

    In the Terra Meridiani- Arabia Terra region of Mars, layered rock units with a range of stratal patterns have been widely reported in the literature, and the record of the spectral signatures indicative of hydrate minerals suggests the existence of aqueous activity in at least some of the stratigraphic units. . In this work we investigated the area in the northern region of Sinus Meridiani located between 2°N to 3°N latitude and 2°W to 1°E longitude, using multiple remote sensing data sets to identify, characterize in detail, and understand the origin and evolution of the selected units in this region of Mars. MOLA and HiRISE data were used in combination to classify and correlate surface units recorded in distinct stratigraphic logs, based on planimetric configuration, topography, morphological and litho-facies characteristics. In particular, detailed analyses were focused on the layered units discovered in the walls of two impact craters located at a distance of about 100 km to each other within the study area. The stratigraphic interval analysed here corresponds to the upper part of the well known "light-toned layered deposits" identified by several authors. Distinct competent layers are observed in the internal slopes of both craters. Our observations indicate that the lithostratigraphic sections can be divided in three units. The lower unit consists of very thick bodies of light-toned bouldery breccia deposits. In the HiRISE images these white-coloured beds are composed of irregularly-shaped, white nodules which are either isolated or coalescent, distributed between bedding planes. The middle unit mainly consists of alternating thin strong layers and thicker sequences of relatively weak layers, horizontally bedded. The strong, competent layers maintain steeper erosional profiles and play a major role in controlling the overall shape and geomorphology of the wall slopes. The upper unit can be traced laterally in the surrounding ground level, displaying mesa

  13. Highest-Resolution View of 'Face on Mars'

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A key aspect of the Mars Global Surveyor (MGS) Extended Mission is the opportunity to turn the spacecraft and point the Mars Orbiter Camera (MOC) at specific features of interest. A chance to point the spacecraft comes about ten times a week. Throughout the Primary Mission (March 1999 - January 2001), nearly all MGS operations were conducted with the spacecraft pointing 'nadir'--that is, straight down. In this orientation, opportunities to hit a specific small feature of interest were in some cases rare, and in other cases non-existent. In April 1998, nearly a year before MGS reached its Primary Mission mapping orbit, several tests of the spacecraft's ability to be pointed at specific features was conducted with great success (e.g., Mars Pathfinder landing site, Viking 1 site, and Cydonia landforms). When the Mars Polar Lander was lost in December 1999, this capability was again employed to search for the missing lander. Following the lander search activities, a plan to conduct similar off-nadir observations during the MGS Extended Mission was put into place. The Extended Mission began February 1, 2001. On April 8, 2001, the first opportunity since April 1998 arose to turn the spacecraft and point the MOC at the popular 'Face on Mars' feature.

    Viking orbiter images acquired in 1976 showed that one of thousands of buttes, mesas, ridges, and knobs in the transition zone between the cratered uplands of western Arabia Terra and the low, northern plains of Mars looked somewhat like a human face. The feature was subsequently popularized as a potential 'alien artifact' in books, tabloids, radio talk shows, television, and even a major motion picture. Given the popularity of this landform, a new high-resolution view was targeted by pointing the spacecraft off-nadir on April 8, 2001. On that date at 20:54 UTC (8:54 p.m., Greenwich time zone), the MGS was rolled 24.8o to the left so that it was looking at the 'face' 165 km to the side from a distance of about 450 km

  14. Bilateral symmetry across Aphrodite Terra

    NASA Technical Reports Server (NTRS)

    Crumpler, L. S.; Head, J. W.; Campbell, D. B.

    1987-01-01

    There are three main highland areas on Venus: Beta Regio, Ishtar Terra and Aphrodite Terra. The latter is least known and the least mapped, yet existing analyses of Aphrodite Terra based on available Pioneer-Venus orbiter data suggest that it may be the site of extensive rifting. Some of the highest resolution (30 km) PV data (SAR) included most of the western half of Aphrodite Terra. Recent analysis of the SAR data together with Arecibo range-doppler topographic profiling (10 X 100 km horizontal and 10 m vertical resolution) across parts of Aphrodite, further characterized the nature of possible tectonic processes in the equatorial highlands. The existence of distinct topographic and radar morphologic linear discontinuities across the nearly east-west strike of Aphrodite Terra is indicated. Another prominent set of linear features is distinctly parallel to and orthogonal to the ground tracks of the PV spacecraft and are not included because of the possibility that they are artifacts. Study of the northwest trending cross-strike discontinuities (CSD's) and the nature of topographic and morphologic features along their strike suggest the presence of bilateral topographic and morphologic symmetry about the long axis of Aphrodite Terra.

  15. A hypersaline spring analogue in Manitoba, Canada for potential ancient spring deposits on Mars

    NASA Astrophysics Data System (ADS)

    Berard, Genevieve; Applin, Daniel; Cloutis, Edward; Stromberg, Jessica; Sharma, Raven; Mann, Paul; Grasby, Stephen; Bezys, Ruth; Horgan, Briony; Londry, Kathleen; Rice, Melissa; Last, Bill; Last, Fawn; Badiou, Pascal; Goldsborough, Gordon; Bell, James

    2013-06-01

    This study explores the possible applications of a spring complex, East German Creek (EGC), Manitoba, Canada, as a terrestrial analogue for similar environments on Mars. Potential ancient spring deposits have been identified by Allen and Oehler (Allen, C.C., Oehler, D.Z. [2008]. Astrobiology 8, 1093-1112) in Vernal Crater, Arabia Terra, as well as in the intercrater plains of Terra Sirenum by Wray et al. (Wray et al. [2011]. J. Geophys. Res., 116, 1-41). EGC can provide guidance in the search for fossil spring deposits on Mars by using comparative mineralogy to contrast mineral identification from field studies to that available from remote sensing instruments such as the CRISM instrument aboard the Mars Reconnaissance Orbiter. The formation processes of EGC are also useful for finding spring-like environments on Mars. A variety of techniques were employed (X-ray diffractometry, reflectance spectra, water chemistry analysis) to analyze mineralogical changes in spring water precipitates with distance from the main springs at EGC, which were compared with concentrations of dissolved species in outflow water. Biosignatures in outflow stream sediments as well as the effect of surficial Fe oxyhydroxide coatings on the detection of underlying carbonate absorption features have also been spectrally characterized. Halite is the main mineral precipitated at EGC, followed by gypsum, and calcite. The presence of gypsum is readily detected in surficial precipitate spectra while halite does not have a diagnostic spectral signature in the 0.35-2.5 μm region. An absorption feature indicative of chlorophyll a is present in stream sediment spectra from most sampling stations and on outwash plain sediments. Carbonates appear to be spectrally detectable through a coating of ferric minerals, such as goethite by a characteristic absorption band near 2.3 μm. We attempted to detect significant spectral changes over an area of potential spring features in Vernal Crater on Mars using

  16. Update: Saudi Arabia.

    ERIC Educational Resources Information Center

    McGregor, Joy; Nydell, Margaret

    A guide for persons planning on living in or relocating to Saudi Arabia for extended periods of time, this book features information on such topics as entry requirements, transportation, money matters, housing, schools, and insurance. The guide's contents include the following sections: (1) an overview; (2) before leaving; (3) on arrival; (4)…

  17. Absolute Measurements of Methane on Mars

    NASA Astrophysics Data System (ADS)

    Mumma, M. J.; Villanueva, G. L.; Novak, R. E.

    2009-12-01

    On Mars, methane has been sought for nearly 40 years because of its potential biological significance, but it was detected only recently [1-5]. Its distribution on the planet is found to be patchy and to vary with time [1,2,4,5], suggesting that methane is released from the subsurface in localized areas, and is then rapidly destroyed [1,6]. To date, we have detected four spectral lines of the CH4 ν3 band near 3.3 µm, along with H2O and HDO [1,5,7]. Our observational campaign resumed in August 2009, now using CRIRES/VLT along with CSHELL/NASA-IRTF and NIRSPEC/Keck. Our study of methane on Mars now extends over four Mars years, sampling a wide range of seasons (Ls) with significant spatial coverage. For a typical observation, the spectrometer's long entrance slit is held to the central meridian of Mars while spectra are taken sequentially in time. For each snapshot in time, spectra are acquired simultaneously at contiguous positions along the entire slit length, sampling latitudinally resolved spatial footprints on the planet (35 footprints along the N-S meridian, when Mars is 7 arc-sec in diameter). Successive longitudes are presented as the planet rotates, and the combination then permits partial mapping of the planet. In Northern summer 2003, methane was notably enriched over several localized areas: A (East of Arabia Terra, where water vapor is also greatly enriched), B1 (Nili Fossae), and B2 (southeast quadrant of Syrtis Major) [1,5]. The combined plume contained ~19,000 metric tons of methane, and the estimated source strength (≥ 0.6 kilogram per second) was comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, California. By vernal equinox about one-half the released methane had been lost. When averaged over latitude and season, spectral data from Mars Express also imply an enhancement in methane in this longitude range [4]. The most compelling results from these searches are: 1) the unambiguous detection of multiple

  18. The Seasonal Cycle of Water Vapour on Mars from Assimilation of Thermal Emission Spectrometer Data

    NASA Technical Reports Server (NTRS)

    Steele, Liam J.; Lewis, Stephen R.; Patel, Manish R.; Montmessin, Franck; Forget, Francois; Smith, Michael D.

    2014-01-01

    We present for the first time an assimilation of Thermal Emission Spectrometer (TES) water vapour column data into a Mars global climate model (MGCM). We discuss the seasonal cycle of water vapour, the processes responsible for the observed water vapour distribution, and the cross-hemispheric water transport. The assimilation scheme is shown to be robust in producing consistent reanalyses, and the global water vapour column error is reduced to around 2-4 pr micron depending on season. Wave activity is shown to play an important role in the water vapour distribution, with topographically steered flows around the Hellas and Argyre basins acting to increase transport in these regions in all seasons. At high northern latitudes, zonal wavenumber 1 and 2 stationary waves during northern summer are responsible for spreading the sublimed water vapour away from the pole. Transport by the zonal wavenumber 2 waves occurs primarily to the west of Tharsis and Arabia Terra and, combined with the effects of western boundary currents, this leads to peak water vapour column abundances here as observed by numerous spacecraft. A net transport of water to the northern hemisphere over the course of one Mars year is calculated, primarily because of the large northwards flux of water vapour which occurs during the local dust storm around L(sub S) = 240-260deg. Finally, outlying frost deposits that surround the north polar cap are shown to be important in creating the peak water vapour column abundances observed during northern summer.

  19. The seasonal cycle of water vapour on Mars from assimilation of Thermal Emission Spectrometer data

    NASA Astrophysics Data System (ADS)

    Steele, Liam J.; Lewis, Stephen R.; Patel, Manish R.; Montmessin, Franck; Forget, François; Smith, Michael D.

    2014-07-01

    We present for the first time an assimilation of Thermal Emission Spectrometer (TES) water vapour column data into a Mars global climate model (MGCM). We discuss the seasonal cycle of water vapour, the processes responsible for the observed water vapour distribution, and the cross-hemispheric water transport. The assimilation scheme is shown to be robust in producing consistent reanalyses, and the global water vapour column error is reduced to around 2-4 pr μm depending on season. Wave activity is shown to play an important role in the water vapour distribution, with topographically steered flows around the Hellas and Argyre basins acting to increase transport in these regions in all seasons. At high northern latitudes, zonal wavenumber 1 and 2 stationary waves during northern summer are responsible for spreading the sublimed water vapour away from the pole. Transport by the zonal wavenumber 2 waves occurs primarily to the west of Tharsis and Arabia Terra and, combined with the effects of western boundary currents, this leads to peak water vapour column abundances here as observed by numerous spacecraft. A net transport of water to the northern hemisphere over the course of one Mars year is calculated, primarily because of the large northwards flux of water vapour which occurs during the local dust storm around LS=240-260°. Finally, outlying frost deposits that surround the north polar cap are shown to be important in creating the peak water vapour column abundances observed during northern summer.

  20. Gravitational Effects of Flooding and Filling of Impact Basins on Mars

    NASA Technical Reports Server (NTRS)

    Smith, David E.; Zuber, Maria T.

    2004-01-01

    The presence of large impact basins and the low northern plains that might have contained ice or liquid water at an earlier stage of Mars evolution suggests that the global gravity field could have been different in the distant past than it is today. In addition, any significant change in the distribution of mass affects the moments of inertia and consequently and could conceivably change the position of the pole and the length of day. Similar effects could have been produced by large erosional processes, such as the removal of crustal material from the Arabia Terra region and subsequent re-deposition in the Chryse region of the northern plains. We have endeavored to estimate the magnitudes of material that might have been involved in these processes and their possible effect on the gravity and dynamics of Mars. We have used present-day topography and gravity field as a starting point, recognizing that both the result of the processes that we are trying to study rather than the state at the times of interest.

  1. SUV Tracks On Mars? The 'Devil' is in the Details

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Sport Utility Vehicles (SUVs) on Mars? Imagine the MOC imaging team's surprise on the morning of April 27, 1998, as the latest images came in from the 'Red Planet.'

    A picture taken by the camera on Mars Global Surveyor just one day earlier showed several thin, dark lines that--at first glance--looked like pathways blazed by off-road sport utility vehicles. Who's been driving around on Mars?

    The MOC image in question (#26403), seen here at full resolution of 13.8 meters (45 feet) per pixel, was obtained around 10:22 a.m. PDT on April 26, 1998, during Mars Global Surveyor's 264th orbit. North is approximately up, illumination is from the lower right. Located in eastern Arabia Terra near 16.5o N latitude, 311.4o W longitude, the image showed a number of natural features--small craters formed by meteor impact, several buttes and mesas left by erosion of the surrounding terrain, small dunes and drifts, and a mantle of dust that varies in thickness from place to place. But the new picture also showed two dark lines--each varying in width up to about 15 meters (49 feet)--that extended several kilometers/miles across the image.

    Lines like these have been seen before on Mars. They are most likely the result of dust devils--columnar vortices of wind that move across the landscape, pick up dust, and look somewhat like miniature tornadoes. Dust devils are a common occurrence in dry and desert landscapes on Earth as well as Mars. They form when the ground heats up during the day, warming the air immediately above the surface. As pockets of warm air rise and interfere with one another, they create horizontal pressure variations that, combined with other meteorological winds, cause the upward moving air to spin (the direction of the spin is controlled by the same Coriolis forces that cause terrestrial hurricanes to spin in specific directions). As the spinning column of air moves across the surface, it occasionally encounters dust on the surface, which it can suck upward

  2. Irrigated Agriculture, Saudi Arabia

    NASA Technical Reports Server (NTRS)

    1990-01-01

    In Saudi Arabia, center-pivot, swing-arm irrigated agriculture complexes such as the one imaged at Jabal Tuwayq (20.5N, 45.0 E) extract deep fossil water reserves to achieve food crop production self sufficiency in this desert environment. The significance of the Saudi expanded irrigated agriculture is that the depletion of this finite water resource is a short term solution to a long term need that will still exist when the water has been extracted.

  3. Major water-related episodes on the lowlands of Mars

    NASA Astrophysics Data System (ADS)

    Fairén, A. G.; Dohm, J. M.; Baker, V. R.

    2003-04-01

    in Arabia Terra, where the initial shoreline might have been as far south as Sinus Meridani (Edgett and Parker, 1997), forming an almost equipotential line (total elevation differences are ˜2 km) that we name Contact 0, which is also consistent with the location of the boundary in crustal thickness dichotomy, as deduced from topography and gravity data (Zuber et al., 2000), and with the locus of debouch of almost every valley network in Arabia (Edgett and Parker, 1997; Carr, 2002); a Late Hesperian sea, which would have extended over the deeper areas in the lowlands inset within the boundary of the first great ocean, and so portrayed by Contact 2; and a number of widely distributed minor lakes that may represent a reduced Late Hesperian sea, or ponded waters in the deepest reaches of the northern plains related to minor Tharsis (e.g., Anderson et al., 2001) and Elysium (Skinner and Tanaka, 2001) induced Amazonian flooding. Possible biologic evolution throughout the resulting different climatic and hydrologic conditions would account for very distinct metabolic pathways for hypothesized organisms capable of surviving and perhaps evolving in each aqueous environment, those that existed in the dry and cold periods between the flood inundations, and those organisms that could survive both extremes. Terrestrial microbiota, chemolithotrophic and heterotrophic bacteria, provide exciting analogues for such potential extremophile existence in Mars, especially where long-lived, magmatic-driven hydrothermal activity is indicated (Farmer and Des Marais, 1999). Such Martian environments and related materials and life forms may have been excavated to the surface by catastrophic outflows making targets readily available for sampling and in-deep analyses. References Anderson, R. C. et al.: Primary centers and secondary concentrations of tectonic activity through time in western hemisphere of Mars. J. Geophys. Res. 106, 20 563--20 585, 2001. Baker, V.R., et al.: Ancient oceans, ice

  4. Science Writers' Guide to TERRA

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The launch of NASA's Terra spacecraft marks a new era of comprehensive monitoring of the Earth's atmosphere, oceans, and continents from a single space-based platform. Data from the five Terra instruments will create continuous, long-term records of the state of the land, oceans, and atmosphere. Together with data from other satellite systems launched by NASA and other countries, Terra will inaugurate a new self-consistent data record that will be gathered over the next 15 years. The science objectives of NASAs Earth Observing System (EOS) program are to provide global observations and scientific understanding of land cover change and global productivity, climate variability and change, natural hazards, and atmospheric ozone. Observations by the Terra instruments will: provide the first global and seasonal measurements of the Earth system, including such critical functions as biological productivity of the land and oceans, snow and ice, surface temperature, clouds, water vapor, and land cover; improve our ability to detect human impacts on the Earth system and climate, identify the "fingerprint" of human activity on climate, and predict climate change by using the new global observations in climate models; help develop technologies for disaster prediction, characterization, and risk reduction from wildfires, volcanoes, floods, and droughts, and start long-term monitoring of global climate change and environmental change.

  5. Relative Ages of the Highlands, Lowlands, and Transition Zone Along a Portion of the Mars Crustal Dichotomy from Densities of Visible and Buried Impact Craters

    NASA Technical Reports Server (NTRS)

    DeSoto, G. E.; Frey, H. V.

    2005-01-01

    Understanding the fundamental age relationships of the different parts of the Mars Crustal Dichotomy is essential to fully understanding the events that shaped the early history and formation of the surface of Mars. A dominant question is what are the true relative ages of the Northern Lowlands and the Southern Highlands? Using MOLA data from the Mars Global Surveyor and Viking visual images, a dataset of both buried and visible crater diameters was created over a nine million sq km study area of a section of the dichotomy boundary stretching from Arabia Terra to Utopia Planitia. Cumulative frequency plots on a log-log scale were used to determine the relative ages for the Highlands, the Lowlands, and the Transition Zone, separately for the visible, the buried and the combined total (visible+ buried) populations. We find the overall Highland crater population in this area is slightly older than the Lowlands, consistent with previous global studies, but the Lowlands and Transition Zone are also very old and formed at roughly the same time. It appears that the formation of the Lowlands in this region formed contemporaneously with a large-scale resurfacing event in the Highlands, perhaps caused by the process responsible for the Lowland formation.

  6. Health Education in Saudi Arabia

    PubMed Central

    Al-Hashem, Anwar

    2016-01-01

    This article provides a historical overview of the evolution of health education in Saudi Arabia. It outlines milestones in the development of the health education profession and traces the roles of various health sectors and their achievements in the health education field. Additionally, this review seeks to describe the status of health education professionals in Saudi Arabia. PMID:27606106

  7. Lunar and Planetary Science XXXV: Mars Geophysics

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The titles in this section include: 1) Distribution of Large Visible and Buried Impact Basins on Mars: Comparison with Free-Air Gravity, Crustal Thickness, and Magnetization Models; 2) The Early Thermal and Magnetic State of Terra Cimmeria, Southern Highlands of Mars; 3) Compatible Vector Components of the Magnetic Field of the Martian Crust; 4) Vertical Extrapolation of Mars Magnetic Potentials; 5) Rock Magnetic Fields Shield the Surface of Mars from Harmful Radiation; 6) Loading-induced Stresses near the Martian Hemispheric Dichotomy Boundary; 7) Growth of the Hemispheric Dichotomy and the Cessation of Plate Tectonics on Mars; 8) A Look at the Interior of Mars; 9) Uncertainties on Mars Interior Parameters Deduced from Orientation Parameters Using Different Radio-Links: Analytical Simulations; 10) Refinement of Phobos Ephemeris Using Mars Orbiter Laser Altimetry Radiometry.

  8. TerraSAR-X mission

    NASA Astrophysics Data System (ADS)

    Werninghaus, Rolf

    2004-01-01

    The TerraSAR-X is a German national SAR- satellite system for scientific and commercial applications. It is the continuation of the scientifically and technologically successful radar missions X-SAR (1994) and SRTM (2000) and will bring the national technology developments DESA and TOPAS into operational use. The space segment of TerraSAR-X is an advanced high-resolution X-Band radar satellite. The system design is based on a sound market analysis performed by Infoterra. The TerraSAR-X features an advanced high-resolution X-Band Synthetic Aperture Radar based on the active phased array technology which allows the operation in Spotlight-, Stripmap- and ScanSAR Mode with various polarizations. It combines the ability to acquire high resolution images for detailed analysis as well as wide swath images for overview applications. In addition, experimental modes like the Dual Receive Antenna Mode allow for full-polarimetric imaging as well as along track interferometry, i.e. moving target identification. The Ground Segment is optimized for flexible response to (scientific and commercial) User requests and fast image product turn-around times. The TerraSAR-X mission will serve two main goals. The first goal is to provide the strongly supportive scientific community with multi-mode X-Band SAR data. The broad spectrum of scientific application areas include Hydrology, Geology, Climatology, Oceanography, Environmental Monitoring and Disaster Monitoring as well as Cartography (DEM Generation) and Interferometry. The second goal is the establishment of a commercial EO-market in Europe which is driven by Infoterra. The commercial goal is the development of a sustainable EO-business so that the e.g. follow-on systems can be completely financed by industry from the profit. Due to its commercial potential, the TerraSAR-X project will be implemented based on a public-private partnership with the Astrium GmbH. This paper will describe first the mission objectives as well as the

  9. Intimations of water on Mars.

    PubMed

    2000-08-01

    This photo essay contains images of Mars that propose evidence of the possible present or past existence of liquid water on Mars. Images were taken by the Mars Global Surveyor Mars Orbiter Camera. Images presented include: Polar Wall Pit region, consisting of gully landforms possibly caused by seepage and runoff of liquid water; Noachis Terra region, an area of gullies eroded into the wall of a meteor impact crater, where channels and related debris are seen, possibly formed by seepage, runoff, and debris flow; two images of Gorgonum Chaos region, one a series of troughs and layers of gullies and the other of gullies in a specific layer forming an alcove similar to an aquifer; Sirenum Fossae/Gorgonum Chaos mosaic of two images from this region of the southern hemisphere of Mars, showing 20 different channels coming down from a trough and their associated debris fans. Images and their enhancements are from NASA/JPL/Malin Space Science System. PMID:11543294

  10. Terra firma-forme dermatosis.

    PubMed

    Oztürk, Ferdi; Kocabaş, Engin; Ertan, Pelin; Ermertcan, Aylin Türel

    2010-12-01

    Terra firma-forme dermatosis (TFFD) is an uncommon disorder of keratinization with an unknown etiology in which patients present with dirt-like lesions that are resistant to washing. A 6-year old girl presented with the complaint of an asymptomatic brownish black dirt-like eruption on her body. Her parents reported no response to washing with soap and water. Dermatologic examination revealed brown hyperpigmented patches on the trunk and abdominal region. TFFD was suspected, and isopropyl alcohol was applied to the patient's lesions. All lesions completely disappeared after rubbing with alcohol. Terra firma-forme dermatosis is a relatively recently described entity that is much more common than might be expected when surveying the medical literature. With the very few reports found in the literature about TFFD, we believe that an increased awareness of this entity among primary care physicians would help decrease unnecessary worries or medical procedures, since TFFD lesions simply resolve by rubbing with isopropyl alcohol. PMID:20684734

  11. The global distribution of near-surface hydrogen on Mars

    SciTech Connect

    Feldman, W. C.; Prettyman, T. H.; Maurice, S.; Bish, D. L.; Vaniman, D. T.; Squyres, Steven W.; Boynton, W. V.; Elphic, R. C.; Funsten, H. O.; Lawrence, David J. ,; Tokar, R. L.; Moore, K. R.

    2004-01-01

    Odyssey neutron observations also revealed a near equatorial hydrogen reservoir that maximizes in Arabia Terra and its antipode. Initial quantitative estimates of hydrogen abundances in these investigations were normalized to an assumed 1% H{sub 2}O content by mass for the Viking 1 landing site. However, a recent analysis of the seasonal variation of the CO{sub 2} frost cover at the north pole has allowed an independent absolute calibration of the three neutron energy bands measured using the NS aboard Mars Odyssey. This calibration allows a reinterpretation of neutron fluxes measured globally to provide a lower bound of the hydrogen abundance within about 1 m of the Martian surface. A determination of true hydrogen abundances requires knowledge of the stratigraphy of hydrogen-bearing layers because the presence of an overlying relatively desiccated layer would mask enhanced abundances of a lower layer.

  12. Variations in Crustal Structure, Lithospheric Flexural Strength, and Isostatic Compensation Mechanisms of Mars

    NASA Astrophysics Data System (ADS)

    Ding, M.; Lin, J.; Zuber, M. T.

    2014-12-01

    We analyze gravity and topography of Mars to investigate the spatial variations in crustal thickness, lithospheric strength, and mechanisms of support of prominent topographic features on Mars. The latest gravity model JGMRO110c (released in 2012) from the Mars Reconnaissance Orbiter mission has a spatial block size resolution of ~97 km (corresponding to degree-110), enabling us to resolve crustal structures at higher spatial resolution than those determined from previous degree-80 and 85 gravity models [Zuber et al., 2000; McGovern et al., 2002, 2004; Neumann et al., 2004; Belleguic et al., 2005]. Using the latest gravity data, we first inverted for a new version of crustal thickness model of Mars assuming homogeneous crust and mantle densities of 2.9 and 3.5 g/cm3. We calculated "isostatic" topography for the Airy local isostatic compensation mechanism, and "non-isostatic" topography after removing the isostatic part. We find that about 92% of the Martian surface is in relatively isostatic state, indicating either relatively small lithospheric strength and/or small vertical loading. Relatively isostatic regions include the hemispheric dichotomy, Hellas and Argyre Planitia, Noachis and Arabia Terra, and Terra Cimmeria. In contrast, regions with significant amount of non-isostatic topography include the Olympus, Ascraeus, Arsia, Pavonis, Alba, and Elysium Mons, Isidis Planitia and Valles Marineris. Their relatively large "non-isostatc topography" implies relatively strong lithospheric strength and large vertical loading. Spectral analysis of the admittance and correlation relationship between gravity and topography were conducted for the non-isostatic regions using the localized spectra method [Wieczorek and Simons, 2005, 2007] and thin-shell lithospheric flexural approximation [Forsyth, 1985; McGovern et al., 2002, 2004]. The best-fitting models reveal significant variations in the effective lithospheric thickness with the greatest values for the Olympus Mon

  13. Mars Ice Age, Simulated

    NASA Technical Reports Server (NTRS)

    2003-01-01

    December 17, 2003

    This simulated view shows Mars as it might have appeared during the height of a possible ice age in geologically recent time.

    Of all Solar System planets, Mars has the climate most like that of Earth. Both are sensitive to small changes in orbit and tilt. During a period about 2.1 million to 400,000 years ago, increased tilt of Mars' rotational axis caused increased solar heating at the poles. A new study using observations from NASA's Mars Global Surveyor and Mars Odyssey orbiters concludes that this polar warming caused mobilization of water vapor and dust into the atmosphere, and buildup of a surface deposit of ice and dust down to about 30 degrees latitude in both hemispheres. That is the equivalent of the southern Unites States or Saudi Arabia on Earth. Mars has been in an interglacial period characterized by less axial tilt for about the last 300,000 years. The ice-rich surface deposit has been degrading in the latitude zone of 30 degrees to 60 degrees as water-ice returns to the poles.

    In this illustration prepared for the December 18, 2003, cover of the journal Nature, the simulated surface deposit is superposed on a topography map based on altitude measurements by Global Surveyor and images from NASA's Viking orbiters of the 1970s.

    Mars Global Surveyor and Mars Odyssey are managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for the NASA Office of Space Science, Washington.

  14. Roughness and near-surface density of Mars from SHARAD radar echoes

    NASA Astrophysics Data System (ADS)

    Campbell, Bruce A.; Putzig, Nathaniel E.; Carter, Lynn M.; Morgan, Gareth A.; Phillips, Roger. J.; Plaut, Jeffrey J.

    2013-03-01

    We present a technique for estimating Mars topographic roughness on horizontal scales from about 10 m to 100 m using Shallow Radar (SHARAD) sounding data. Our results offer a view of surface properties complementary to Mars Orbiter Laser Altimeter (MOLA) pulse-width or baseline roughness maps and can be compared to SHARAD peak-echo properties to infer deviations from the average near-surface density. Latitudinal averaging of SHARAD-derived roughness over Arabia and Noachis Terrae shows good agreement with MOLA-derived roughness and provides clear evidence for latitude-dependent mantling deposits previously inferred from image data. In northwestern Gordii Dorsum, we find that bulk density in at least the upper few meters is significantly lower than in other units of the Medusae Fossae Formation. We observe the same behavior indicative of low near-surface density in wind-eroded crater fill in the southern highlands. Combining surface-properties analysis, subsurface sounding, and high-resolution optical images, we show that the Pavonis Mons fan-shaped deposit differs significantly from lobate debris aprons which SHARAD has shown to be ice-cored. There are no internal radar reflections from the smooth-facies portion of the Pavonis Mons fan-shaped deposit, and we suggest that these deposits are either quite thin or have little dielectric (i.e., density) contrast with the underlying terrain. Future application of these techniques can identify other low-density units across Mars, assist in the mapping of regional volatile-rich mantling units, and provide new constraints on the physical properties of the polar layered terrain.

  15. Terra Nova Bay Polynya, Antarctica

    NASA Technical Reports Server (NTRS)

    2007-01-01

    In Terra Nova Bay, off the Scott Coast of Victoria Land, Antarctica, a large pocket of open water persists throughout most of the Southern Hemisphere winter, even while most of the rest of the Antarctic coastline is firmly embraced by the frozen Southern Ocean. This pocket of open water--a polynya--results from exceptionally strong winds that blow downslope from the Trans-Antarctic Mountains. These fierce katabatic winds drive the sea ice eastward. Since the dominant ice drift pattern in the area is northward, the Drygalski Ice Tongue prevents the bay from being re-populated with sea ice. This image of the Terra Nova Bay polynya was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite on October 16, 2007. Sea ice sits over the Ross Sea like a cracked and crumbling windshield. Blue-tinged glaciers flow down from the Trans-Antarctic Mountains. Although glaciers can appear blue because of melt water, they can also get that tint when the wind scours and polishes the ice surface. Given the strength of the katabatic winds along this part of the Antarctic coast, it is likely that the blue color of these glaciers is a result of their having been swept clean of snow. The large image has a spatial resolution (level of detail) of 250 meters per pixel.

  16. Geologic history and channeling episodes of the Chryse Planitia region of Mars

    NASA Astrophysics Data System (ADS)

    Rotto, Susan L.; Tanaka, Kenneth L.

    1991-06-01

    The study of the Chryse Planitia region of Mars is based on geologic mapping on a 1:5,000,000 scale shaded relief map. The map area includes Chryse and southern Acidalia Planitiae; the circum Chryse channels and chaotic terrains; Xanthe, southern Tempe, and western Arabia Terrae; Lunae Planum; and northeastern Valles Marineris. The aim of the study is twofold: (1) to obtain relative ages of the outflow channels by performing and compiling detailed stratigraphic analyses; and (2) to correlate channeling episodes with causative mechanisms (such as volcanism and tectonism) and resulting effects (such as climate change). The geologic history given based on this mapping, includes the documentation of a previously unproposed channeling episode in the region as well as the presently favored hypotheses concerning the nature and origin of the channeling events. It is concluded that the history of the Chryse region suggests that two major periods of tectonic activity resulted in two episodes of channeling in the highlands surrounding Chryse Planitia.

  17. Mars Through the Eye of HiRISE

    NASA Astrophysics Data System (ADS)

    McEwen, A. S.; Hirise, T.

    2007-05-01

    The High Resolution Imaging Science Experiment (HiRISE) has acquired more than 2 Tb of data in more than 1,000 images of Mars at resolutions as high as 25 cm/pixel in the 3 PM mapping orbit of Mars Reconnaissance Orbiter. Each image consists of data from up to 14 CCD detectors and could contain as many as 3 giga-pixels. Early results include (1) improved knowledge of the stratigraphy of the north polar layered deposits and the origin of the thick basal unit; (2) discovery that rocks are uniformly abundant in the Vastitas Borealis Formation covering the northern lowlands; (3) imaging of past landing sites has provided new insights and surprises about the nature of these surfaces; (4) fine layered deposits in Valles Marineris, Meridiani Planum, Arabia Terra and elsewhere are often cut by indurated and/or bleached joints and faults, most likely due to precipitation from fluids; (5) regions of Mars rich in phyllosilicate minerals [Murchie et al., submitted] are seen to consist of layered deposits with fine-scale fractures and polygons; (6) lava flows through Athabasca Valles were surprisingly thick flows that were deflated and drained, leaving behind a veneer of lava with abundant evidence for lava-water interactions; (7) stratigraphic studies reveal two major episodes of fluvial/lacustrine activity in Holden crater, and we've detected exposures of ancient megabreccia in the crater walls; (8) recent large (3-60 km) impact craters have created a range of apparently fluvially-modified landforms; (9) a small cluster of craters from a very recent impact event created a large (~2 km) wide blast zone with thousands of dust avalanches; (10) relatively bright deposits associated with very recent activities in gullies appear to consist of materials eroded from the crater slopes; (11) the south polar residual cap of CO2 has a range of newly-discovered morphologies that constrain models for landscape evolution; and(12) geysers or cold jets associated with sublimation of the

  18. First dinosaurs from Saudi Arabia.

    PubMed

    Kear, Benjamin P; Rich, Thomas H; Vickers-Rich, Patricia; Ali, Mohammed A; Al-Mufarreh, Yahya A; Matari, Adel H; Al-Massari, Abdu M; Nasser, Abdulaziz H; Attia, Yousry; Halawani, Mohammed A

    2013-01-01

    Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (~ 75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids - this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region. PMID:24386326

  19. First Dinosaurs from Saudi Arabia

    PubMed Central

    Kear, Benjamin P.; Rich, Thomas H.; Vickers-Rich, Patricia; Ali, Mohammed A.; Al-Mufarreh, Yahya A.; Matari, Adel H.; Al-Massari, Abdu M.; Nasser, Abdulaziz H.; Halawani, Mohammed A.

    2013-01-01

    Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (∼75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids – this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region. PMID:24386326

  20. Rub' al Khali, Arabia

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Rub' al Khali is one of the largest sand deserts in the world, encompassing most of the southern third of the Arabian Peninsula. It includes parts of Oman, United Arab Emirates, and Yemen. The desert covers 650,000 square kilometers, more than the area of France. Largely unexplored until recently, the desert is 1000 km long and 500 km wide. The first documented journeys made by Westerners were those of Bertram Thomas in 1931 and St. John Philby in 1932. With daytime temperatures reaching 55 degrees Celsius, and dunes taller than 330 meters, the desert may be one of the most forbidding places on Earth.

    The image was acquired December 2, 2005, covers an area of 54.8 x 61.9 km, and is located near 20.7 degrees north latitude, 53.6 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  1. Adult Education in Saudi Arabia.

    ERIC Educational Resources Information Center

    Griffin, Tim D.; Algren, Mark S.

    Religion pervades all aspects of Saudi Arabia, the conservative home of Islam, where the constitution is the Quran and law is interpreted by religious scholars. A formal adult basic education program was initiated in 1960. As part of the country's modernization since the early 1970s, the Saudi government has begun an enormous nation-building plan…

  2. Social Education in Saudi Arabia.

    ERIC Educational Resources Information Center

    Al-Jabr, Soliman M.

    1990-01-01

    Reveals some cultural aspects of Saudi Arabian Islamic society and the role social studies education plays in it. States that the National Council for the Social Studies in Saudia Arabia stipulates general social studies goals and allows teachers to make specific behavioral goals. Concludes that Saudi Arabian schools are becoming more modern. (GG)

  3. Tectonic implications of Mars crustal magnetism.

    PubMed

    Connerney, J E P; Acuña, M H; Ness, N F; Kletetschka, G; Mitchell, D L; Lin, R P; Reme, H

    2005-10-18

    Mars currently has no global magnetic field of internal origin but must have had one in the past, when the crust acquired intense magnetization, presumably by cooling in the presence of an Earth-like magnetic field (thermoremanent magnetization). A new map of the magnetic field of Mars, compiled by using measurements acquired at an approximately 400-km mapping altitude by the Mars Global Surveyor spacecraft, is presented here. The increased spatial resolution and sensitivity of this map provide new insight into the origin and evolution of the Mars crust. Variations in the crustal magnetic field appear in association with major faults, some previously identified in imagery and topography (Cerberus Rupes and Valles Marineris). Two parallel great faults are identified in Terra Meridiani by offset magnetic field contours. They appear similar to transform faults that occur in oceanic crust on Earth, and support the notion that the Mars crust formed during an early era of plate tectonics. PMID:16217034

  4. Tectonic implications of Mars crustal magnetism

    PubMed Central

    Connerney, J. E. P.; Acuña, M. H.; Ness, N. F.; Kletetschka, G.; Mitchell, D. L.; Lin, R. P.; Reme, H.

    2005-01-01

    Mars currently has no global magnetic field of internal origin but must have had one in the past, when the crust acquired intense magnetization, presumably by cooling in the presence of an Earth-like magnetic field (thermoremanent magnetization). A new map of the magnetic field of Mars, compiled by using measurements acquired at an ≈400-km mapping altitude by the Mars Global Surveyor spacecraft, is presented here. The increased spatial resolution and sensitivity of this map provide new insight into the origin and evolution of the Mars crust. Variations in the crustal magnetic field appear in association with major faults, some previously identified in imagery and topography (Cerberus Rupes and Valles Marineris). Two parallel great faults are identified in Terra Meridiani by offset magnetic field contours. They appear similar to transform faults that occur in oceanic crust on Earth, and support the notion that the Mars crust formed during an early era of plate tectonics. PMID:16217034

  5. DEMONSTRATION BULLETIN: TERRA KLEEN SOLVENT EXTRACTION TECHNOLOGY - TERRA-KLEEN RESPONSE GROUP, INC.

    EPA Science Inventory

    The Terra-Kleen Solvent Extraction Technology was developed by Terra-Kleen Response Group, Inc., to remove polychlorinated biphenyls (PCB) and other organic constituents from contaminated soil. This batch process system uses a proprietary solvent at ambient temperatures to treat ...

  6. The Earth Observing System Terra Mission

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.

    2000-01-01

    Langley's remarkable solar and lunar spectra collected from Mt. Whitney inspired Arrhenius to develop the first quantitative climate model in 1896. After the launch in Dec. 16 1999, NASA's Earth Observing AM Satellite (EOS-Terra) will repeat Langley's experiment, but for the entire planet, thus pioneering a wide array of calibrated spectral observations from space of the Earth System. Conceived in response to real environmental problems, EOS-Terra, in conjunction with other international satellite efforts, will fill a major gap in current efforts by providing quantitative global data sets with a resolution smaller than 1 km on the physical, chemical and biological elements of the earth system. Thus, like Langley's data, EOS-Terra can revolutionize climate research by inspiring a new generation of climate system models and enable us to assess the human impact on the environment. In the talk I shall review the historical perspective of the Terra mission and the key new elements of the mission. We expect to have some first images that demonstrate the most innovative capability from EOS Terra: MODIS - 1.37 microns cirrus channel; 250 m daily cover for clouds and vegetation change; 7 solar channels for land and aerosol; new fire channels; Chlorophyll fluorescence; MISR - 9 multi angle views of clouds and vegetation; MOPITT - Global CO maps and CH4 maps; ASTER - Thermal channels for geological studies with 15-90 m resolution.

  7. The Earth Observing System Terra Mission

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Langley's remarkable solar and lunar spectra collected from Mt. Whitney inspired Arrhenius to develop the first quantitative climate model in 1896. After the launch in Dec. 16 1999, NASA's Earth Observing AM Satellite (EOS-Terra) will repeat Langley's experiment, but for the entire planet, thus pioneering a wide array of calibrated spectral observations from space of the Earth System. Conceived in response to real environmental problems, EOS-Terra, in conjunction with other international satellite efforts, will fill a major gap in current efforts by providing quantitative global data sets with a resolution better than 1 km on the physical, chemical and biological elements of the earth system. Thus, like Langley's data, EOS-Terra can revolutionize climate research by inspiring a new generation of climate system models and enable us to assess the human impact on the environment. In the talk I shall review the historical perspective of the Terra mission and the key new elements of the mission. We expect to have first images that demonstrate the most innovative capability from EOS Terra 5 instruments: MODIS - 1.37 micron cirrus cloud channel; 250m daily coverage for clouds and vegetation change; 7 solar channels for land and aerosol studies; new fire channels; Chlorophyll fluorescence; MISR - first 9 multi angle views of clouds and vegetation; MOPITT - first global CO maps and C114 maps; ASTER - Thermal channels for geological studies with 15-90 m resolution.

  8. Terra - the Earth Observing System flagship observatory

    NASA Astrophysics Data System (ADS)

    Thome, K. J.

    2013-12-01

    The Terra platform enters its teenage years with an array of accomplishments but also with the potential to do much more. Efforts continue to extend the Terra data record to build upon its array of accomplishments and make its data more valuable by creating a record length that allows examination of inter annual variability, observe trends on the decadal scale, and gather statistics relevant to the define climate metrics. Continued data from Terra's complementary instruments will play a key role in creating the data record needed for scientists to develop an understanding of our climate system. Terra's suite of instruments: ASTER (contributed by the Japanese Ministry of Economy and Trade and Industry with a JPL-led US Science Team), CERES (NASA LaRC - PI), MISR (JPL - PI), MODIS (NASA GSFC), and MOPITT (sponsored by Canadian Space Agency with NCAR-led Science Team) are providing an unprecedented 81 core data products. The annual demand for Terra data remains with >120 million files distributed in 2011 and >157 million in 2012. More than 1,100 peer-reviewed publications appeared in 2012 using Terra data bringing the lifetime total >7,600. Citation numbers of 21,000 for 2012 and over 100,000 for the mission's lifetime. The broad range of products enable the community to provide answers to the overarching question, 'How is the Earth changing and what are the consequences for life on Earth?' Terra continues to provide data that: (1) Extend the baseline of morning-orbit collections; (2) Enable comparison of measurements acquired from past high-impact events; (3) Add value to recently-launched and soon-to-be launched missions, and upcoming field programs. Terra data continue to support monitoring and relief efforts for natural and man-made disasters that involve U.S. interests. Terra also contributes to Applications Focus Areas supporting the U.S. National Objectives for agriculture, air quality, climate, disaster management, ecological forecasting, public health, water

  9. DETAIL OF ORNAMENTAL TERRA COTTA FRIEZE ABOVE GROUND FLOOR AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF ORNAMENTAL TERRA COTTA FRIEZE ABOVE GROUND FLOOR AND TYPICAL TERRA COTTA WINDOW SILL. CORNER OF CLAY AND 15TH STREETS - John Breuner & Company Building, 1515 Clay Street, Oakland, Alameda County, CA

  10. Scaling the Pipe: NASA EOS Terra Data Systems at 10

    NASA Technical Reports Server (NTRS)

    Wolfe, Robert E.; Ramapriyan, Hampapuram K.

    2010-01-01

    Standard products from the five sensors on NASA's Earth Observing System's (EOS) Terra satellite are being used world-wide for earth science research and applications. This paper describes the evolution of the Terra data systems over the last decade in which the distributed systems that produce, archive and distribute high quality Terra data products were scaled by two orders of magnitude.

  11. Connecting Students across Universities in Saudi Arabia

    ERIC Educational Resources Information Center

    Al-Jarf, Reima Sado

    2005-01-01

    The present study reports results of an experiment in which the author and her students at King Saud University (KSU) in Riyadh, Saudi Arabia shared an online grammar course with a professor and his students at Umm Al-Qura University (UQU) in Makkah, Saudi Arabia using www.makkahelearning.net. The experiment proved to be a total failure. Factors…

  12. Health Education in Saudi Arabia: Historical overview.

    PubMed

    Al-Hashem, Anwar

    2016-08-01

    This article provides a historical overview of the evolution of health education in Saudi Arabia. It outlines milestones in the development of the health education profession and traces the roles of various health sectors and their achievements in the health education field. Additionally, this review seeks to describe the status of health education professionals in Saudi Arabia. PMID:27606106

  13. Development of Higher Education in Saudi Arabia.

    ERIC Educational Resources Information Center

    Saleh, Mahmoud Abdullah

    1986-01-01

    The history of higher education in Saudi Arabia is outlined, especially as it relates to Islamic religion and educational philosophy, and its rapid growth is chronicled. These aspects are examined: Saudi students studying abroad, foreign students in Saudi Arabia, women's education, the Ministry of Higher Education's role, and financing. (MSE)

  14. ES4 Terra-Xtrk Ed3

    Atmospheric Science Data Center

    2016-06-08

    ... Order:  Reverb   Reverb Tutorial Order Data:  Reverb:  Order Data Guide Documents:  ... for Terra and Aqua; Edition2 for TRMM) are approved for science publications.  Additional Info:  b SCAR-B ...

  15. Mars Landscapes

    NASA Video Gallery

    Spacecraft have studied the Martian surface for decades, giving Earthlings insights into the history, climate and geology of our nearest neighbor, Mars. These images are from "Mars Landscapes," a v...

  16. Terra in K-16 formal education settings

    NASA Astrophysics Data System (ADS)

    Chambers, L. H.; Fischer, J. D.; Lewis, P. M.; Moore, S. W.; Oots, P. C.; Rogerson, T. M.; Hitke, K. M.; Riebeek, H.

    2009-12-01

    Since it began, the Terra mission has had an active presence in formal education at the K-16 level. This educational presence was provided through the S’COOL project for the first five years of the mission, joined by the MY NASA DATA project for the second five years. The Students’ Cloud Observations On-Line (S’COOL) Project, begun in 1997 under the auspices of the Clouds and the Earth’s Radiant Energy System (CERES) project, seeks to motivate students across the entire K-12 spectrum to learn science basics and how they tie in to a larger picture. Beginning early on, college level participants have also participated in the project, both in science classes and in science education coursework. The project uses the connection to an on-going NASA science investigation as a powerful motivator for student observations, analysis and learning, and has reached around the globe as shown in the world map. This poster will review the impact that Terra, through S’COOL, has made in formal education over the last decade. The MY NASA DATA Project began in 2004 under the NASA Research, Education and Applications Solutions Network (REASoN). A 5-year REASoN grant enabled the creation of an extensive website which wraps easily accessible Earth science data - including Terra parameters from CERES (involving MODIS data fusion), MISR, and MOPITT (an example for carbon monoxide is given in the graph, with dark areas indicating high CO levels) - with explanatory material written at the middle school level, and an extensive collection of peer-reviewed lesson plans. The MY NASA DATA site has a rapidly growing user-base and was recently adopted by a number of NASA Earth Science missions, in addition to Terra, as a formal education arm of their Education and Public Outreach efforts. This poster will summarize the contributions that Terra, through MY NASA DATA, has made to formal education since 2004.

  17. Terra Populus and DataNet Collaboration

    NASA Astrophysics Data System (ADS)

    Kugler, T.; Ruggles, S.; Fitch, C. A.; Clark, P. D.; Sobek, M.; Van Riper, D.

    2012-12-01

    Terra Populus, part of NSF's new DataNet initiative, is developing organizational and technical infrastructure to integrate, preserve, and disseminate data describing changes in the human population and environment over time. Terra Populus will incorporate large microdata and aggregate census datasets from the United States and around the world, as well as land use, land cover, climate and other environmental datasets. These data are widely dispersed, exist in a variety of data structures, have incompatible or inadequate metadata, and have incompatible geographic identifiers. Terra Populus is developing methods of integrating data from different domains and translating across data structures based on spatio-temporal linkages among data contents. The new infrastructure will enable researchers to identify and merge data from heterogeneous sources to study the relationships between human behavior and the natural world. Terra Populus will partner with data archives, data producers, and data users to create a sustainable international organization that will guarantee preservation and access over multiple decades. Terra Populus is also collaborating with the other projects in the DataNet initiative - DataONE, the DataNet Federation Consortium (DFC) and Sustainable Environment-Actionable Data (SEAD). Taken together, the four projects address aspects of the entire data lifecycle, including planning, collection, documentation, discovery, integration, curation, preservation, and collaboration; and encompass a wide range of disciplines including earth sciences, ecology, social sciences, hydrology, oceanography, and engineering. The four projects are pursuing activities to share data, tools, and expertise between pairs of projects as well as collaborating across the DataNet program on issues of cyberinfrastructure and community engagement. Topics to be addressed through program-wide collaboration include technical, organizational, and financial sustainability; semantic

  18. Central Saudi Arabia, Persian Gulf

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This panoramic view of Central Saudi Arabia and the Persian Gulf (28.0N, 47.0E) dramatically illustrates the stark beauty of the deserts. Riyadh, the capital city, lies in the foreground, with the Persian Gulf in the middle and Iran in the background. The coastal oil terminals of Al Hufuf and Ad Dammam are also visible. Black smudges of soot from the oil fires set during the Gulf War can be seen on the sands to the north and south of Kuwait City.

  19. Euripus Mons - Landform Evolution and Climate Constraints in Promethei Terra

    NASA Astrophysics Data System (ADS)

    van Gasselt, Stephan; Kim, Jungrack; Baik, Hyun-Seob

    2016-04-01

    The Promethei Terra region of Mars exhibits a variety of geomorphic landforms indicative of ice-assisted creep of debris and ice, similar to features and processes found at the Martian dichotomy boundary in Deuteronilus, Protonilus and Nilosyrtis Mensae. Despite only little doubt about the fact that ice played an integral role in the formation of these features, it is still disputed if these features were formed by glacial processes, requiring precipitation of ice and snow and exhibiting glacial deformation and basal sliding, or if these landforms are a product of periglacial denudation and subject to different deformation regimes. As information about past climate conditions on Mars is sparse, the proper assessment of landform types today allows to put constraints on their environmental conditions in the past. Due to limited knowledge about the internal physical and thermal structure of these landforms, it remains impossible to unambiguously determine their origin [1]. A variety of geomorphic and model-based indicators need to be taken into account when putting constraints on their history and when trying to reconstruct their evolution. For selected features on Mars it has been shown by SHARAD radar observations that the ice content might be relatively high [2], and that some of them might be composed of pure ice, protected from sublimation by a thin debris cover. One of such examples, Euripus Mons, is a 80 km remnant feature with an associated circumferential talus deposit that shows indicators for deformation by downslope movement, i.e. debris apron morphology. Recent modelling assuming glacial deformation helped to reconstruct some internal structural properties [3]. Despite these attempts, Euripus Mons shows clear geomorphic signatures of classical periglacial denudation which do not fit into the concept of glacial-only evolution. Denudation rates as well as ages are similar to those reported from other locations on Mars for which hyperarid climate conditions

  20. First Self-Consistent, Two-Layer Model of Near-Surface Water-Equivalent-Hydrogen on Mars

    NASA Astrophysics Data System (ADS)

    Feldman, W. C.; Pathare, A.; Prettyman, T. H.; Maurice, S.

    2015-12-01

    This study uses 9.5 years of Mars Odyssey Neutron Spectrometer (MONS) data [1]. We have used the epithermal and fast neutron count rates to determine the water-equivalent-hydrogen (WEH) content of an upper layer, Wup, having thickness D. The "crossover" technique we utilized is an improvement over previous work [2,3]. We then used Monte Carlo simulated grids of epithermal and thermal count rates spanning Wup = 1% to 15% [4] to determine the WEH content, Wdn, of a semi-infinite lower layer buried at depth, D. We also advance upon previous work by using improved deconvolution methods to reduce spatial blurring in fast and epithermal maps [5]. The resultant count-rates were digitized into a 2°x2°cylindrical grid for all WEH computations. Two sets of WEH maps will be shown. The first uses the one-layer model developed initially by Feldman et al. [6]. Comparison of the undeconvolved and deconvolved versions clearly illustrates the improvement obtained by deconvolution. We will also present the full two layer maps of Wup, Wdn, and D for the deconvolved data sets, which show: 1) contrary to our previous preliminary mapping [3], the fresh icy mid-latitude craters identified by [7] are NOT exclusively found in regions with average Wdn values that exceed the pore-filling threshold for regolith ice; 2) a maximum Wdn of about 80% by weight at the Phoenix site; 3) an isolated Wdn maximum just east of Gale crater that is centered on Aeolis Mensae; 4) a resolved Wdn maximum that overlays the Orsen Wells crater on Xanthe Terra; 5) Wdn local maxima that hug the western flanks of Olympus Mons and Elysium Mons, and 6) several Wdn maxima that cover Arabia Terra. We will present and interpret regional maps of all of these features. Refs: [1] Maurice et al. JGR, 2011; [2] Feldman et al. JGR, 2011; [3] Pathare et al. 8th Mars Conf., 2014; [4] Prettyman et al. JGR, 2004 [5] Prettyman et al. JGR, 2009; [6] Feldman et al. JGR, 2004; [7] Dundas et al. JGR, 2014.

  1. Monitoring on Xi'an ground fissures deformation with TerraSAR-X data

    USGS Publications Warehouse

    Zhao, C.; Zhang, Q.; Zhu, W.; Lu, Zhiming

    2012-01-01

    Owing to the fine resolution of TerraSAR-X data provided since 2007, this paper applied 6 TerraSAR data (strip mode) during 3rd Dec. 2009 to 23rd Mar. 2010 to detect and monitor the active fissures over Xi'an region. Three themes have been designed for high precision detection and monitoring of Xi'an-Chang'an fissures, as small baseline subsets (SBAS) to test the atmospheric effects of differential interferograms pair stepwise, 2-pass differential interferogram with very short baseline perpendicular to generate the whole deformation map with 44 days interval, and finally, corner reflector (CR) technique was used to closely monitor the relative deformation time series between two CRs settled crossing two ground fissures. Results showed that TerraSAR data are a good choice for small-scale ground fissures detection and monitoring, while special considerations should be taken for their great temporal and baseline decorrelation. Secondly, ground fissures in Xi'an were mostly detected at the joint section of stable and deformable regions. Lastly, CR-InSAR had potential ability to monitor relative deformation crossing fissures with millimeter precision.

  2. Volatile-rich Crater Interior Deposits on Mars: An Energy Balance Model of Modification

    NASA Technical Reports Server (NTRS)

    Russell, Patrick S.; Head, James W.; Hecht, Michael H.

    2003-01-01

    Several craters on Mars are partially filled by material emplaced by post-impact processes. Populations of such craters include those in the circumsouth polar cap region, in Arabia Terra, associated with the Medusae Fossae Formation, and in the northern lowlands proximal to the north polar cap. In this study, crater fill material refers to an interior mound, generally separated from the interior walls of the crater by a trough that may be continuous along the crater s circumference (i.e. a ring-shaped trough), or may only partially contact the crater walls (i.e. a crescent-shaped trough). The fill deposit is frequently off-center from the crater center and may be asymmetric, (i.e. not circular) in plan view shape. Here we test the hypothesis that asymmetries in volatile fill shape, profile, and center-location within a crater result from asymmetries in local energy balance within the crater due mainly to variation of solar insolation and radiative effects of the crater walls over the crater interior. We first focus on Korolev crater in the northern lowlands. We can then apply this model to other craters in different regions. If asymmetry in morphology and location of crater fill are consistent with radiative-dominated asymmetries in energy budget within the crater, then 1) the volatile-rich composition of the fill is supported (this process should not be effective at shaping volcanic or sedimentary deposits), and 2) the dominant factor determining the observed shape of volatile-rich crater fill is the local radiative energy budget within the crater (and erosive processes such as eolian deflation are not necessary).

  3. New composite spectra of Mars, 0.4-5.7 μm

    USGS Publications Warehouse

    Erard, Stephane; Calvin, Wendy M.

    1997-01-01

    About 15 areas were observed in the equatorial regions of Mars by the infrared spectrometers IRS (Mariner 6 and 7) and ISM (Phobos-2). The comparison between the spectra shows a remarkable consistency between two data sets acquired 20 years apart and calibrated independently. This similarity demonstrates the accuracy of ISM calibration above 2 μm, except for a possible stray light contribution above 2.6 μm, on the order of ∼1–2% of the solar flux at 2.7 μm. Most differences in spectral shapes are related to differences in spectral/spatial resolution and viewing geometries. No important variation in surface properties is detected, except for a spot in southern Arabia Terra which has a much deeper hydration feature in IRS spectra; differences in viewing geometries and spatial resolutions do not seem to account for this difference that could result from shifting or dehydration of surface materials. Composite spectra of several types of bright and dark materials are computed by modeling the thermal emission and are completed with telescopic spectra in the visible range. Modeled reflectance in the 3.0–5.7 μm range is consistent with basalts and palagonites. The bright regions and analog palagonite spectra are different from hematite in this range, but resemble several phyllosilicates. We infer that (1) although hematite dominates the spectra in the 0.4- to 2.5-μm range, the silicate-clay host is spectrally active beyond 3 μm and can be identified from this domain; (2) phyllosilicates such as montmorillonite or smectite may be abundant components of the martian soils, although the domain below 3 μm lacks the characteristic features of the most usual terrestrial clay minerals.

  4. The Global Distribution of Weathered Glass on Mars

    NASA Astrophysics Data System (ADS)

    Horgan, B.; Chojnacki, M.; Lai, J.; Clarke, D.; Joseph, J.; Bell, J. F.

    2012-12-01

    Weathered iron-bearing glass has been identified as the primary phase in over ten million square kilometers of low-albedo deposits in the northern lowlands of Mars, based on visible to near-infrared (0.36-2.5 μm) spectra from the OMEGA imaging spectrometer onboard Mars Express (Horgan and Bell, 2012). The glass exhibits a concave blue slope in the near-infrared that is consistent with a leached glass rind. This rind is formed during exposure of glass to at least slightly acidic fluids under water-limited conditions, and is commonly observed in dry volcanic environments on Earth. The proposed origin for these materials is explosive volcanism, potentially triggered due to ice-magma interactions in the late Hesperian or Amazonian, followed by post-depositional acidic weathering at the surface. A possible analog for these glass-rich sedimentary terrains are the extensive sand plains, dune fields, and flood plains of Iceland, which are composed of glass-rich (50-90%) volcaniclastic sediments formed during sub-glacial eruptions. The large scale of the martian deposits suggests widespread (and potentially ice-related) explosive volcanism either in the northern lowlands or near the dichotomy boundary. This possibility raises the question: How widespread are glass-rich deposits on Mars globally? To address this question, we have developed a global set of visible/near-infrared OMEGA mosaics at 1 km/pixel resolution. Preliminary analysis of this data set indicates that the concave spectral slope that we associate with weathered glass is present in large portions of the Syrtis Major region, within Mawrth Vallis, and in several dozen dune fields in the regions of Syrtis Major, Arabia Terra, Valles Marineris, and the Argyre Basin. Higher resolution CRISM observations of several Valles Marineris dune fields appear to confirm these preliminary results, as spectra within the dune fields are consistent with iron-bearing glass (Chojnacki et al., 2012). We are currently working to

  5. Partially-Exhumed Crater in Northern Terra Meridiani: Stereo Anaglyph of overlapping coverage in

    NASA Technical Reports Server (NTRS)

    2002-01-01

    MGS MOC Release No. MOC2-316, 8 August 2002 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images have shown time and again that the geology and history of Mars is complex. These two pictures show different views of a circular feature in northern Terra Meridiani at 2.3oN, 356.6oW. The first is a mosaic of 3 MOC narrow angle images acquired in August 1999, November 2000, and June 2002. The black area is a gap in coverage resulting from data lost after transmission from Mars to Earth. The second picture is a stereo ('3-D') anaglyph of a portion of the same circular feature. It has been rotated 90o clockwise to show the stereo effect that results from combining the August 1999 image, which was taken while the spacecraft was pointed nadir (straight down) and the June 2002 image, taken with the spacecraft pointing backwards about 16o (i.e., MGS Relay-16 orientation). The anaglyph should be viewed with '3-D' glasses (red in left eye, blue in the right). The circular feature was once an impact crater. The crater was 2.6 km (1.6 mi) across, about 2.6 times larger than the famous Meteor Crater in northern Arizona. Terra Meridiani, like northern Arizona, is a region of vast exposures of layered sedimentary rock. Like the crater in Arizona, this one was formed by a meteor that impacted a layered rock substrate. Later, this crater was filled and completely buried under more than 100 m (more than 327 ft) of additional layered sediment. The sediment hardened to become rock. Later still, the rock was eroded away--by processes unknown (perhaps wind)--to re-expose the buried crater. The crater today remains mostly filled with sediment, its present rim standing only about 40 m (130 ft) above its surroundings.

  6. Geologic Mapping in Southern Margaritifer Terra

    NASA Technical Reports Server (NTRS)

    Irwin, R. P., III; Grant, J. A.

    2010-01-01

    Margaritifer Terra records a complex geologic history [1-5], and the area from Holden crater through Ladon Valles, Ladon basin, and up to Morava Valles is no exception [e.g., 6-13]. The 1:500,000 geologic map of MTM quadrangles -15027, -20027, -25027, and -25032 (Figs. 1 and 2 [14]) identifies a range of units that delineate the history of water-related activity and regional geologic context.

  7. Vicarious calibration of Aqua and Terra MODIS

    NASA Astrophysics Data System (ADS)

    Thome, Kurtis J.; Czapla-Myers, Jeffrey S.; Biggar, Stuart F.

    2003-11-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) is onboard both the Terra and Aqua platforms. An important aspect of the use of MODIS, and other Earth Science Enterprise sensors, has been the characterization and calibration of the sensors and validation of their data products. The Remote Sensing Group at the University of Arizona has been active in this area through the use of ground- based test sites. This paper presents the results from the reflectance-base approach using the Railroad Valley Playa test site in Nevada for both Aqua and Terra MODIS. The key to the approach is the measurement of surface reflectance over a 1-km2 area of the playa and results from this method shows agreement with both MODIS sensors to better than 5%. Early results indicate that while the two sensors both agree with the ground-based measurements to within the uncertainties of the reflectance-based approach, there were significant differences between the Aqua and Terra MODIS for data prior to September 2002. Recent results indicate that this bias, if any, is now within the uncertainties of the reflectance-based method of calibration.

  8. Is Ishtar Terra a thickened basaltic crust?

    NASA Technical Reports Server (NTRS)

    Arkani-Hamed, Jafar

    1992-01-01

    The mountain belts of Ishtar Terra and the surrounding tesserae are interpreted as compressional regions. The gravity and surface topography of western Ishtar Terra suggest a thick crust of 60-110 km that results from crustal thickening through tectonic processes. Underthrusting was proposed for the regions along Danu Montes and Itzpapalotl Tessera. Crustal thickening was suggested for the entire Ishtar Terra. In this study, three lithospheric models with total thicknesses of 40.75 and 120 km and initial crustal thicknesses of 3.9 and 18 km are examined. These models could be produced by partial melting and chemical differentiation in the upper mantle of a colder, an Earth-like, and a hotter Venus having temperatures of respectively 1300 C, 1400 C, and 1500 C at the base of their thermal boundary layers associated with mantle convection. The effects of basalt-granulite-eclogite transformation (BGET) on the surface topography of a thickening basaltic crust is investigated adopting the experimental phase diagram and density variations through the phase transformation.

  9. Future of energy demand in Saudi Arabia

    SciTech Connect

    Elshayal, I.M.; Al-Zakri, A.S.

    1981-01-01

    In this study, the most recent papers on this topic were reviewed to examine the future use of nuclear energy in seawater desalination and electric power generation, as well as its impact on the environment in Saudi Arabia. 14 refs.

  10. Geologic Mapping of the Nili Fossae Region of Mars: MTM Quadrangles 20287, 20282, 25287, 25282, 30287, and 30282

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III; Crown, David A.

    2010-01-01

    Geologic mapping studies at the 1:1M-scale are being used to assess geologic materials and processes that shape the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will provide a regional context and evaluate the distribution, stratigraphic position, and potential lateral continuity of compositionally distinct outcrops identified by spectral instruments currently in orbit (i.e., CRISM and OMEGA). Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary may provide constraints on: 1) origin of the dichotomy boundary, 2) paleoenvironments and climate conditions, and 3) various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes, including hydrothermal alteration, across the region.

  11. Terra Mission Operations: Launch to the Present (and Beyond)

    NASA Technical Reports Server (NTRS)

    Kelly, Angelita; Moyer, Eric; Mantziaras, Dimitrios; Case, Warren

    2014-01-01

    The Terra satellite, flagship of NASA's long-term Earth Observing System (EOS) Program, continues to provide useful earth science observations well past its 5-year design lifetime. This paper describes the evolution of Terra operations, including challenges and successes and the steps taken to preserve science requirements and prolong spacecraft life. Working cooperatively with the Terra science and instrument teams, including NASA's international partners, the mission operations team has successfully kept the Terra operating continuously, resolving challenges and adjusting operations as needed. Terra retains all of its observing capabilities (except Short Wave Infrared) despite its age. The paper also describes concepts for future operations. This paper will review the Terra spacecraft mission successes and unique spacecraft component designs that provided significant benefits extending mission life and science. In addition, it discusses special activities as well as anomalies and corresponding recovery efforts. Lastly, it discusses future plans for continued operations.

  12. NASA's Terra spacecraft is prepared for encapsulation before launch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Workers at Vandenberg AFB, Calif., help prepare NASA's Terra spacecraft (right) for encapsulation in the rocket faring (left). Terra is expected to be launched aboard a Lockheed Martin Atlas IIAS rocket Dec. 16 from Space Launch Complex 3 East at Vandenberg. Terra comprises five state-of-the-art sets of instruments that will collect data for continuous, long-term records of the state of Earth's land, oceans and atmosphere. Together with data from other satellite systems launched by NASA and other countries, Terra will inaugurate a new self-consistent data record that will be gathered over the next 15 years. From an altitude of 438 miles, Terra will circle the Earth 16 times a day from pole to pole (98 degree inclination), crossing the equator at 10:30 a.m. The five Terra instruments will operate by measuring sunlight reflected by the Earth and heat emitted by the Earth.

  13. NASA's Terra spacecraft is prepared for encapsulation before launch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    NASA's Terra spacecraft (foreground) is ready for encapsulation in the rocket faring behind it. Terra is expected to be launched aboard a Lockheed Martin Atlas IIAS rocket Dec. 16 from Space Launch Complex 3 East at Vandenberg AFB, Calif. Terra comprises five state-of-the-art sets of instruments that will collect data for continuous, long-term records of the state of Earth's land, oceans and atmosphere. Together with data from other satellite systems launched by NASA and other countries, Terra will inaugurate a new self-consistent data record that will be gathered over the next 15 years. From an altitude of 438 miles, Terra will circle the Earth 16 times a day from pole to pole (98 degree inclination), crossing the equator at 10:30 a.m. The five Terra instruments will operate by measuring sunlight reflected by the Earth and heat emitted by the Earth.

  14. Organ Transplantation in Saudi Arabia.

    PubMed

    Shaheen, Faissal A M

    2016-07-01

    Organ transplantation started in the Kingdom of Saudi Arabia (KSA) in 1979 with a kidney transplanted from a live donor. The Saudi Center for Organ Transplantation has been established in 1985 as a governmental agency that supervises all national transplant activities in the KSA. Organ transplantation in the KSA has made great strides since 1985. Saudi Center for Organ Transplantation is playing a central role in all aspects of transplantation including education on all levels, allocation, coordination and procurement. A new initiative has started an ambitious program in 2014 to improve the identification and reporting of organ donors aiming at an annual rate of 15 donors per million populations within 3 years in the KSA. PMID:27326805

  15. Multihued Mars

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken at JPL shows the panoramic camera used onboard both Mars Exploration Rovers. The panel to the lower right highlights the multicolored filter wheel that allows the camera to see a rainbow of colors, in addition to infrared bands of light. By seeing Mars in all its colors, scientists can gain insight into the different minerals that constitute its rocks and soil.

  16. Geologic Mapping of the Mawrth Vallis Region, Mars: MTM Quadrangles 25022, 25017, 25012, 20022, 20017, and 20012

    NASA Technical Reports Server (NTRS)

    Chuang, F. C.; Bleamaster, L. F., III

    2010-01-01

    Mawrth Vallis is a 15-25 km wide, 500 km long sinuous channel that winds through the highlands of Arabia Terra and debouches into the lowlands of Acidalia Planitia. The Mawrth Vallis region lies along the gradational zone between southern hemisphere thick crust and northern hemisphere thin crust, a topographically distinct portion of the Martian crustal dichotomy. The origin and age of the dichotomy boundary are controversial and are further complicated by the multi-stage and multi-process geologic history that has modified this approximately 6000 km section of the highland-lowland boundary (approximately 5 N, 330E to approximately 30 N, 80 E; herein referred as the Arabia Terra boundary). Furthermore, the Arabia Terra boundary has been subjected to many post-boundary processes such as outflow floods to the west, volcanism and tectonism to the east, and potential volatile deposition and glacial modification to the north. This study seeks to better understand the history of the Mawrth Vallis region by mapping six MTM quadrangles (17.5-27.5 N, 335-350 E) at 1:1M scale using traditional and modern digital geologic mapping techniques.

  17. Topographic Analyses of the Vestalia Terra plateau, Vesta (Invited)

    NASA Astrophysics Data System (ADS)

    Buczkowski, D.; Wyrick, D. Y.; Williams, D. A.; Preusker, F.; Roatsch, T.; DeSanctis, M. C.; Raymond, C. A.; Russell, C. T.

    2013-12-01

    The identification of Vestalia Terra, a topographically high region of Vesta bound by steep scarps, is itself a direct result of topographic analysis of the asteroid. However, additional analysis of the topography of the plateau has yielded important scientific discoveries. While most equatorial regions on Vesta display numerous wide and flat-floored troughs, Vestalia Terra does not. There are, however, three long pit crater chains on top of the plateau that are roughly aligned with the equatorial flat-floor troughs. Pit crater chains are a type of feature that have been observed on several planetary bodies and have been described as lines of circular to elliptical depressions which lack an elevated rim, ejecta deposits, or lava flows. Individual pits most commonly have a conical shape, sometimes with a flat floor, but in some cases they are elliptical in shape, with the long axis parallel to the chain orientation. Pit craters can in many cases coalesce into linear troughs, but the pits are often bordered by a graben (a down-dropped block bounded by normal faults) even before this coalesence. While pits are generally agreed to have formed by collapse into a subsurface cavity, the exact formation mechanisms hypothesized can vary from planet to planet. However, several researchers have suggested that pit crater chains on small bodies such as Phobos, Eros, Lutetia and Enceladus are formed by the drainage of a loose cover material into subsurface voids formed by dilation of a subsurface normal fault, a method described in extensive detail for pit crater chains on Mars. This formation hypothesis is strengthened by the strong correlation between pit crater chains and fault-bounded graben that has been observed and by the fact that pit chains are often in alignment with a regional fault and fracture system. There are two fundamental controls on the maximum size a pit can attain: the thickness of the overlying regolith and the amount of subsurface accommodation space. The

  18. Volcanism in Northwest Ishtar Terra, Venus

    SciTech Connect

    Gaddis, L.R.; Greeley, R. )

    1990-10-01

    Evidence is presented for a previously undocumented volcanic complex in the highlands of NW Ishtar Terra (74 deg N, 313 deg E). The proposed valcanic center is in mountainous banded terrain thought to have been formed by regional compression. Data used include Soviet Venera 15/16 radar images and topography (Fotokarta Veneri B-4, 1987). An attempt is made to assess the place of this feature in the framework of known volcanic landforms of the Lakshmi Planum and to examine the relationships between volcanism and tectonism in this region. 38 refs.

  19. Terra firma-forme dermatosis revisited.

    PubMed

    Browning, John; Rosen, Ted

    2005-01-01

    Terra firma-forme dermatosis is a cutaneous discoloration resembling dirt, hence the clinical name. The dyschromia cannot be removed with routine soap and water washing, but can be eliminated by rubbing with isopropyl alcohol. Although the condition poses no serious medical threat, it is cosmetically distressing. Our experience is that this entity is much more frequent that might be expected when considering the paucity of reports in the readily available medical literature. We chronicle a series of cases to highlight occurrence in widely divergent demographic groups and long duration of remission following appropriate topical intervention. The cause remains unknown. PMID:16150223

  20. Crustal Evolution of the Protonilus Mensae Area, Mars

    NASA Technical Reports Server (NTRS)

    McGill, G. E.; Smrekar, S. E.; Dimitriou, A. M.; Raymond, C. A.

    2004-01-01

    Despite research by numerous geologists and geo- physicists, the age and origin of the martian crustal dichotomy remain uncertain. Models for the origin of this dichotomy involve single or multiple impact, mantle megaplumes, primordial crustal asymmetry, and plate tectonics. Most of these models imply a Noachian age for the dichotomy. A major problem common to all genetic models is the difficulty separating the features resulting from the primary cause for the dichotomy from features due to younger fault- ing, impact cratering, volcanism, deposition, and erosion. highlands (the dichotomy boundary) approximates a small circle that ranges in latitude from about -10 deg. in Elysium Planitia to about +45 deg. north of Arabia Terra. For much of its length the boundary is characterized by relatively steep scarps separating highland plateau to the south from lowland plains to the north, generally with a complex transition zone on the lowland side of these scarps. These scarps are almost certainly due to normal faulting. The type fretted terrain, which defines the boundary in north-central Arabia Terra, also is characterized by scarps but has under- gone a more complex history of faulting and dissection [13]. In some places, notably in the Acidalia Planitia region, the dichotomy boundary is gradational. In the Tharsis region the boundary is obscured by younger volcanics.

  1. Pedogenetic processes on Mars

    NASA Astrophysics Data System (ADS)

    Chiara Tangari, Anna; Marinangeli, Lucia; Piluso, Eugenio; Pompilio, Loredana; Scarciglia, Fabio

    2014-05-01

    Clay minerals, such as Fe/Mg smectite and Al-rich phyllosilicates (i.e., montmorillonite and kaolinite) were detected in the last years on Mars by numerous missions[1,2]. These minerals can be formed by fluid/rock interaction. Therefore, their study may provide important information on the climatic conditions and consequent habitability of the Martian surface. In this work we compare the mineralogy observed with CRISM data in the eastern part of Valles Marineris (Coprates-Ganges-Capri-Eos Chasmata), Margaritifer Terra and Margaritifer Chaos regions, with soils sampled on the Etna volcano (Sicily) and Cerviero Mount (Calabria, Southern Italy). We use an integrated approach of remote sensing coupled with pedological, petrographical and mineralogical investigations. Our purpose, here, is to find possible analogies between some Andosols developed on the basaltic substrates of Etna and Cerviero Mount, and the Martian soils, based on their spectral response and formation processes. CRISM data show poor abundance of clay minerals, such as illite, smectite and montmorillonite, in the eastern part of Valles Marineris. On the contrary, these phases are widely exposed in the Margaritifer Terra and Margaritifer Chaos, where we detected allophone (poorly crystalline clay), vermiculite, chlorite and other phyllosilicates belonging to the smectite group, such as saponite and nontronite. The surrounding area shows dominant signatures of basaltic composition.Our preliminary analysis on terrestrial soil profiles, using X-ray diffraction analysis, shows similar characteristics to Mars in terms of bedrock composition and clay mineralogy. Etnean soils, formed from lavas and pyroclastics of various ages (from 12 ka to 122 BC) [3] show the presence of clay minerals, such as kaolinite and small amounts of illite. The Cerviero Mount soils, developed on pillow basalts of Maastrichtian-Paleocene ages [4] are composed of vermiculite, illite, chlorite and interstratified clays such as

  2. Near and Thermal Infrared Remote Sensing of Bedrock and Sand in Dust-Covered Regions on Mars: Assessing Bedrock Mineralogy Through 'Windows' in the Dust

    NASA Astrophysics Data System (ADS)

    Lai, J. C.; Horgan, B. H.; Bell, J. F.

    2013-12-01

    Bright surface dust masks large regions of Mars from detailed mineralogical and petrological analysis using remote sensing. In order to help address this issue, we assessed a number of orbital data sets to identify and characterize small 'windows' through the dust that may reveal the underlying bedrock. Data sets assessed include the Mars Global Surveyor orbiter (MGS) Thermal Emission Spectrometer (TES) Dust Cover Index (DCI), Mars Odyssey orbiter Thermal Emission Imaging System (THEMIS) thermal imaging, and Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) color mapping observations. Data from the MGS Mars Orbiter Laser Altimeter (MOLA) and high-resolution visible-wavelength images from the MRO Context Camera (CTX) and High Resolution Imaging Science Experiment (HiRISE) provided important topographical and morphological context. We have identified and characterized 67 individual windows in four classically bright regions of Mars: Amazonis Planitia, Arabia Terra, Elysium Planitia, and Tharsis Montes. These windows are characterized by having one or more of the following characteristics in contrast with the surrounding terrain: low DCI value, low MARCI and/or TES albedo, and/or high THEMIS night/day temperature contrast. Windows are typically tens of kilometers across but larger ones hundreds of km across have also been found, most notably in Tharsis. The majority of windows are associated with impact craters, most commonly as intracrater splotches or streaks of warm and/or dark material emanating from the crater. Some of these craters contain outcrops and, in some cases, distinct layers of dark material on their walls or central mound, providing opportunities to analyze bedrock. Other types of windows have also been found in smaller numbers, including those located on the flanks and summits of Mars' most prominent volcanoes, in addition to the walls and bases of cliffs tens to hundreds of meters in height. Initial near-IR spectroscopic analysis using our

  3. Mars Underground News.

    NASA Astrophysics Data System (ADS)

    Edgett, K.

    Contents: Next entry to Mars (Mars Pathfinder and the microrover Sojourner). Hello, Mars, we're back! Mars Global Surveyor update. The Mars program - 2001 and beyond. Schedule of missions to Mars (as of June 11, 1997). Mars on the Web.

  4. Synthesis of Spectral Data From the Grey Hematite Regions of Mars

    NASA Astrophysics Data System (ADS)

    Calvin, W.; Fallacaro, A.; Baldridge, A.

    2003-12-01

    The martian surface has been mapped by a number of visible and infrared spectral instruments from orbit. Telescopic and historical data sets noted the global albedo distribution of bright and dark units. Work in the near infrared (1 to 5 μ m) identified subtle spectral variations and the appearance of areas with unique signatures. Broad classification of color and near-infrared spectral units include bright ferric material (dust), dark ferrous material (mafic rocks and pyroxene), dark ``crystalline'' ferric material (low albedo but with strong ferric absorptions) and water of hydration in surface materials. The Thermal Emission Spectrometer (TES) on MGS has identified two dominant surface units (mafic/basaltic and basaltic/andesitic-or-glassy-or-weathered). Small outcrops where the spectral signature of bulk grey hematite is exposed at the surface have been identified in Meridiani, Aram Chaos and Valles Marineris. Data from both the Infrared Spectrometers (IRS) on Mariner 6 and 7 and the Imaging Spectrometer for Mars (ISM) show the hematite locations to be more hydrated than other surface regions. Initial comparisons between ISM and the Gamma Ray Spectrometer (GRS) on Odyssey show the increased infrared signature of water in regions also found by GRS to contain more hydrogen. The GRS also shows a broad enhancement of hydrogen over Meridiani and Arabia which covers the hematite outcrop but is much larger in extent. This can be explained if GRS is sensitive both to surface hydration and water at depth in minerals or ice. The preferred interpretation for the bulk hematite units is an aqueous precipitate and synthesis of multiple spectral data sets support that conclusion. A synthesis of the data from these instruments at the hematite locations will be presented. The largest of the sites, in Terra Meridiani, is the landing site for the ``Opportunity'' Mars Exploration Rover which lands Jan 25, 2004. Consideration of constraints imposed by these orbital data sets

  5. Role of TERRA in the Regulation of Telomere Length

    PubMed Central

    Wang, Caiqin; Zhao, Li; Lu, Shiming

    2015-01-01

    Telomere dysfunction is closely associated with human diseases such as cancer and ageing. Inappropriate changes in telomere length and/or structure result in telomere dysfunction. Telomeres have been considered to be transcriptionally silent, but it was recently demonstrated that mammalian telomeres are transcribed into telomeric repeat-containing RNA (TERRA). TERRA, a long non-coding RNA, participates in the regulation of telomere length, telomerase activity and heterochromatinization. The correct regulation of telomere length may be crucial to telomeric homeostasis and functions. Here, we summarize recent advances in our understanding of the crucial role of TERRA in the maintenance of telomere length, with focus on the variety of mechanisms by which TERRA is involved in the regulation of telomere length. This review aims to enable further understanding of how TERRA-targeted drugs can target telomere-related diseases. PMID:25678850

  6. NASA's Terra spacecraft is prepared for encapsulation before launch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Workers (left) at Vandenberg AFB, Calif., get ready to prepare NASA's Terra spacecraft (right) for encapsulation in the rocket faring (left) before launch. The spacecraft is expected to be launched Dec. 16 aboard a Lockheed Martin Atlas IIAS rocket from the AFB's Space Launch Complex 3 East. Terra comprises five state-of-the-art sets of instruments that will collect data for continuous, long-term records of the state of Earth's land, oceans and atmosphere. Together with data from other satellite systems launched by NASA and other countries, Terra will inaugurate a new self-consistent data record that will be gathered over the next 15 years. From an altitude of 438 miles, Terra will circle the Earth 16 times a day from pole to pole (98 degree inclination), crossing the equator at 10:30 a.m. The five Terra instruments will operate by measuring sunlight reflected by the Earth and heat emitted by the Earth.

  7. NASA's Terra spacecraft is prepared for encapsulation before launch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    NASA's Terra spacecraft awaits installation of the instruments that will collect data for continuous, long-term records of the state of Earth's land, oceans and atmosphere. Terra is expected to be launched aboard a Lockheed Martin Atlas IIAS rocket Dec. 16 from Space Launch Complex 3 East at Vandenberg AFB, Calif. Terra comprises five state-of-the-art sets of instruments that, together with data from other satellite systems launched by NASA and other countries, will inaugurate a new self-consistent data record that will be gathered over the next 15 years. From an altitude of 438 miles, Terra will circle the Earth 16 times a day from pole to pole (98 degree inclination), crossing the equator at 10:30 a.m. The five Terra instruments will operate by measuring sunlight reflected by the Earth and heat emitted by the Earth.

  8. Mars Bowling

    NASA Video Gallery

    More than 140 fourth and fifth graders from Kraft Elementary School in Hampton learned how Newton's laws of motion apply to bowling and the Mars Curiosity rover during "The Science of Bowling," an ...

  9. Hydrogeology of Basins on Mars

    NASA Technical Reports Server (NTRS)

    Arvidson, Raymond E.

    2001-01-01

    This document summarizes the work accomplished under NASA Grant NAG5-3870. Emphasis was put on the development of the FIDO rover, a prototype for the twin-Mers which will be operating on the surface of Mars in 2004, specifically the primary work was the analysis of FIDO field trials. The grantees also analyzed VIKING Lander 1 XRFS and Pathfinder APXS data. Results show that the Viking site chemistry is consistent with an andesite, and the Pathfinder site is consistent with a basaltic andesite. The grantees also worked to demonstrate the capability to simulate annealing methods to apply to the inversion of remote sensing data. They performed an initial analyses of Sojourner engineering telemetry and imaging data. They performed initial analyses of Viking Lander Stereo Images, and of Hematite deposits in Terra Meridiani. They also acquired and analyzed the New Goldstone radar data.

  10. Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    First of NASA's Discovery missions. Launched in December 1996 and arrived at Mars on 4 July 1997. Mainly intended as a technology demonstration mission. Used airbags to cushion the landing on Mars. The Carl Sagan Memorial station returned images of an ancient flood plain in Ares Vallis. The 10 kg Sojourner rover used an x-ray spectrometer to study the composition of rocks and travelled about 100 ...

  11. Mars resources

    NASA Technical Reports Server (NTRS)

    Duke, Michael B.

    1986-01-01

    The most important resources of Mars for the early exploration phase will be oxygen and water, derived from the Martian atmosphere and regolith, which will be used for propellant and life support. Rocks and soils may be used in unprocessed form as shielding materials for habitats, or in minimally processed form to expand habitable living and work space. Resources necessary to conduct manufacturing and agricultural projects are potentially available, but will await advanced stages of Mars habitation before they are utilized.

  12. Exploring Mars

    NASA Astrophysics Data System (ADS)

    Breuil, Stéphanie

    2016-04-01

    Mars is our neighbour planet and has always fascinated humans as it has been seen as a potential abode for life. Knowledge about Mars is huge and was constructed step by step through numerous missions. It could be difficult to describe these missions, the associated technology, the results, the questions they raise, that's why an activity is proposed, that directly interests students. Their production is presented in the poster. Step 1: The main Mars feature and the first Mars explorations using telescope are presented to students. It should be really interesting to present "Mars Canals" from Percival Lowell as it should also warn students against flawed interpretation. Moreover, this study has raised the big question about extra-terrestrial life on Mars for the first time. Using Google Mars is then a good way to show the huge knowledge we have on the planet and to introduce modern missions. Step 2: Students have to choose and describe one of the Mars mission from ESA and NASA. They should work in pairs. Web sites from ESA and NASA are available and the teacher makes sure the main missions will be studied. Step 3: Students have to collect different pieces of information about the mission - When? Which technology? What were the main results? What type of questions does it raise? They prepare an oral presentation in the form they want (role play, academic presentation, using a poster, PowerPoint). They also have to produce playing cards about the mission that could be put on a timeline. Step 4: As a conclusion, the different cards concerning different missions are mixed. Groups of students receive cards and they have to put them on a timeline as fast as possible. It is also possible to play the game "timeline".

  13. Mars Exploration Program and Mars Technology Program

    NASA Technical Reports Server (NTRS)

    Whetsel, Charles W.

    2002-01-01

    The Mars Exploration Program and constituent Mars Technology Program are described. Current, ongoing and future NASA-led missions are presented, including discussions of scientific accomplishments and objectives as well as technology validations accomplished and technological enablers for future missions. The missions summarized include (in order of actual or planned launch): Mars Global Surveyor, Mars Pathfinder, 2001 Mars Odyssey, Mars Reconnaissance Orbiter, Mars 'Smart' Lander, Mars Scouts, Mars Sample Return. Key technology areas hdiscussed include: Navigation, Entry, Descent and Landing, Science and Surface Operations, Orbital Transport and Sample Return Technologies.

  14. Validation of CERES/TERRA Data

    NASA Technical Reports Server (NTRS)

    Barkstrom, Bruce R.; Wieliski, Bruce A.; Smith, G. Louis; Lee, Robert B.; Priestley, Kory J.; Charlock, Thomas P.; Kratz, David P.

    2000-01-01

    There are 2 CERES scanning radiometer instruments aboard the TERRA spacecraft, one for mapping the solar radiation reflected from the Earth and the outgoing longwave radiation and the other for measuring the anisotropy of the radiation. Each CERES instrument has on-board calibration devices, which have demonstrated that from ground to orbit the broadband total and shortwave sensor responses maintained their ties to the International Temperature Scale of 1990 at precisions approaching radiances have been validated in orbit to +/- 0.3 % (0.3 W/sq m sr). Top of atmosphere fluxes are produced by use of the CERES data alone. By including data from other instruments, surface radiation fluxes and radiant fluxes within the atmosphere and at its top, shortwave and longwave, for both up and down components, are derived. Validation of these data products requires ground and aircraft measurements of fluxes and of cloud properties.

  15. Bilateral topographic symmetry patterns across Aphrodite Terra, Venus

    NASA Technical Reports Server (NTRS)

    Crumpler, L. S.; Head, James W.

    1988-01-01

    Topographic profiles have been obtained across Aphrodite Terra to test for bilateral symmetry of the type associated with thermal boundary layer topography at divergent plate boundaries on earth. In addition to a broad bilateral symmetry at a range of angles across Aphrodite Terra, detailed bilateral symmetry is noted within domains between linear discontinuities in directions parallel to the strike of the discontinuities. The results suggest that western Aphrodite Terra is similar to terrestrial oceanic divergent plate boundary environments, and that the cross-strike discontinuities are analogous to oceanic fracture zones rather than strike-slip faults.

  16. Physical therapy education in Saudi Arabia

    PubMed Central

    Alghadir, Ahmad; Zafar, Hamayun; Iqbal, Zaheen Ahmed; Anwer, Shahnawaz

    2015-01-01

    [Purpose] To review the physical therapy educational program model, professional curriculum, and gender representation at major universities, as well as the quality and scope of physical therapy practice in Saudi Arabia. [Methods] Information regarding course curriculum, gender representation, and the quality and scope of physical therapy practice was collected from six universities in Saudi Arabia, the Saudi Physical Therapy Association, and the Saudi Health Commission. [Results] The first bachelor’s degree course of physical therapy was started in Saudi Arabia more than 30 years ago. In the last 10 years, the number of universities offering a bachelor’s degree in physical therapy has risen from 6 to 16, of which 14 are governmental and two are private. The 5- to 6 year bachelor’s degree program in physiotherapy includes an internship and preparatory prerequisite courses. Postgraduate study in physical therapy was introduced in 2000. Most universities offer segregated physical therapy courses for male and female students. [Conclusion] The enrollment of students in physical therapy programs in Saudi Arabia is gradually increasing. There are many opportunities to extend the scope of practice and contribute to the health needs of the Arab population and international communities. PMID:26157276

  17. Cenozoic volcanic rocks of Saudi Arabia

    USGS Publications Warehouse

    Coleman, R.G.; Gregory, R.T.; Brown, G.F.

    2016-01-01

    The historical record of volcanic activity in Saudi Arabia suggests that volcanism is dormant. The harrats should be evaluated for their potential as volcanic hazards and as sources of geothermal energy. The volcanic rocks are natural traps for groundwater; thus water resources for agriculture may be significant and should be investigated.

  18. English Language Teaching Profile: Saudi Arabia.

    ERIC Educational Resources Information Center

    British Council, London (England). English Language and Literature Div.

    The role and status of English in Saudi Arabia are examined, with attention directed to: (1) English within the education system; (2) teachers of English; (3) English outside the education system; (4) materials support; (5) British support for the teaching of English; and (6) English syllabi at intermediate, secondary, and higher education levels.…

  19. The Education of Women in Saudi Arabia.

    ERIC Educational Resources Information Center

    Al Rawaf, Haya Saad; Simmons, Cyril

    1991-01-01

    Describes the development and expansion of formal education for women in Saudi Arabia since 1960. Discusses girls' curriculum in elementary and secondary schools, the influence of conservative attitudes toward sex roles, and the growth of female higher education despite a lack of female employment. Contains 20 references. (SV)

  20. Making a Smart Campus in Saudi Arabia

    ERIC Educational Resources Information Center

    Abuelyaman, Eltayab Salih

    2008-01-01

    Prince Sultan University (PSU) in Riyadh, Saudi Arabia, has conceptualized what it means to be a smart campus after surveying similar notions worldwide. A "smart" campus requires smart teachers, smart technology, and smart pedagogical centers. It deploys smart teachers and gives them smart tools and ongoing support to do their jobs while…

  1. Online Continuing Medical Education in Saudi Arabia

    ERIC Educational Resources Information Center

    Alwadie, Adnan D.

    2013-01-01

    As the largest country in the Middle East, Saudi Arabia and its health care system are well positioned to embark on an online learning intervention so that health care providers in all areas of the country have the resources for updating their professional knowledge and skills. After a brief introduction, online continuing medical education is…

  2. Completion and Submission of the Terra Sirenum Map Project

    NASA Astrophysics Data System (ADS)

    Anderson, R. C.; Dohm, J. M.; Robbins, S.; Schroeder, J.

    2016-06-01

    We have completed and plan to submit a detailed 1:5,000,000-scale geologic map of the Terra Sirenum region, which includes mapping stratigraphic units and identifying tectonic, erosional, depositional, and impact structures.

  3. TERRA promotes telomerase-mediated telomere elongation in Schizosaccharomyces pombe.

    PubMed

    Moravec, Martin; Wischnewski, Harry; Bah, Amadou; Hu, Yan; Liu, Na; Lafranchi, Lorenzo; King, Megan C; Azzalin, Claus M

    2016-07-01

    Telomerase-mediated telomere elongation provides cell populations with the ability to proliferate indefinitely. Telomerase is capable of recognizing and extending the shortest telomeres in cells; nevertheless, how this mechanism is executed remains unclear. Here, we show that, in the fission yeast Schizosaccharomyces pombe, shortened telomeres are highly transcribed into the evolutionarily conserved long noncoding RNA TERRA A fraction of TERRA produced upon telomere shortening is polyadenylated and largely devoid of telomeric repeats, and furthermore, telomerase physically interacts with this polyadenylated TERRA in vivo We also show that experimentally enhanced transcription of a manipulated telomere promotes its association with telomerase and concomitant elongation. Our data represent the first direct evidence that TERRA stimulates telomerase recruitment and activity at chromosome ends in an organism with human-like telomeres. PMID:27154402

  4. 4. DETAIL OF TERRA COTTA DECORATION AT TOP OF EXPRESSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL OF TERRA COTTA DECORATION AT TOP OF EXPRESSED COLUMN, JUST ABOVE FOURTH FLOOR WINDOWS ON SOUTH FRONT FACADE - John D. Van Allen & Son Store, South Fifth Avenue & Second Street, Clinton, Clinton County, IA

  5. 3. DETAIL OF TERRA COTTA DECORATION ON LOWER END OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. DETAIL OF TERRA COTTA DECORATION ON LOWER END OF EXPRESSED COLUMN, JUST BELOW SECOND FLOOR ON SOUTH FRONT FACADE - John D. Van Allen & Son Store, South Fifth Avenue & Second Street, Clinton, Clinton County, IA

  6. Detail, terra cotta, ironwork, and painted wood "worm gear" carved ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail, terra cotta, ironwork, and painted wood "worm gear" carved columns, north rear. - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  7. SSF Terra-FM1 Ed3A

    Atmospheric Science Data Center

    2016-07-13

    SSF Terra-FM1 Ed3A Project Title:  CERES Discipline:  Clouds Radiation Budget ...   Reverb Tutorial Subset/Visualization Tool: CERES Order Tool Subset Data:  CERES Search and Subset Tool (HDF4 & ...

  8. NASA's Terra spacecraft is prepared for encapsulation before launch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The rocket faring is lifted up the launch tower for mating with the Lockheed Martin Atlas IIAS rocket after encapsulation of Terra, formerly EOS AM-1. It is scheduled for launch Dec. 16 from Space Launch Complex 3 East at Vandenberg AFB, Calif. Terra comprises five state-of-the-art sets of instruments that will collect data for continuous, long-term records of the state of Earth's land, oceans and atmosphere. Together with data from other satellite systems launched by NASA and other countries, it will inaugurate a new self-consistent data record that will be gathered over the next 15 years. From an altitude of 438 miles, Terra will circle the Earth 16 times a day from pole to pole (98 degree inclination), crossing the equator at 10:30 a.m. The five Terra instruments will operate by measuring sunlight reflected by the Earth and heat emitted by the Earth.

  9. Mars 2003

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-402, 25 June 2003

    The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) experiment consists of 3 different cameras: a narrow angle imager that provides the black-and-white high resolution views (up to 1.4 meters per pixel) of Mars, and 2 wide angle cameras, observing in red and blue wavelengths, from which color views of the entire planet are assembled each day. The wide angle cameras provide a daily record of changes in martian weather and surface frost as the seasons progress. MGS MOC has obtained a record of martian weather spanning a little over 2 martian years since it began systematic observations in March 1999.

    The view of Mars shown here was assembled from MOC daily global images obtained on May 12, 2003. At that time, the northern hemisphere was in early autumn, and the southern hemisphere in early spring. At the left/center of this view are the four large Tharsis volcanoes: Olympus Mons, Ascraeus Mons, Pavonis Mons, and Arsia Mons. Stretching across the center of the globe is the 5,000 kilometers (3,000 miles) long Valles Marineris trough system. The seasonal south polar carbon dioxide frost cap is visible at the bottom of this view. A dust storm sweeps across the plains of northern Acidalia at the upper right. North is up, east is right, sunlight illuminates the planet from the left.

  10. Case study of climatic changes in Martian fluvial systems at Xanthe Terra

    NASA Astrophysics Data System (ADS)

    Kereszturi, Akos

    2014-06-01

    An unnamed valley system was analyzed in Xanthe Terra south of Havel Vallis on Mars where three separate episodes of fluvial activity could be identified with different morphology, water source and erosional processes, inferring formation under different climatic conditions. The oldest scattered valleys (1. group) form interconnecting network and suggest areally distributed water source. Later two valley types formed from confined water source partly supported by possible subsurface water. The smaller upper reaches (2. group) with three separate segments and also a similar aged but areal washed terrain suggest contribution from shallow subsurface inflow. These valleys fed the main channel (3. group), which morphology (wide, theater shaped source, few tributaries, steep walls) is the most compatible with the subsurface sapping origin. While the first valley group formed in the Noachian, the other two, more confined groups are younger. Their crater density based age value is uncertain, and could be only 1200 million years. After these three fluvial episodes etch pitted, heavily eroded terrain formed possibly by ice sublimation driven collapse. More recently (60-200 million years ago) dunes covered the bottom of the valleys, and finally the youngest event took place when mass movements produced debris covered the valleys' slopes with sediments along their wall around 5-15 million years ago, suggesting wind activity finished earlier than the mass movements in the region. This small area represents the sequence of events probably appeared on global scale: the general cooling and drying environment of Mars. Comparing the longitudinal profiles here to other valleys in Xanthe Terra, convex shaped valley profiles are usually connected to steep terrains. The location of erosional base might play an important role in their formation that can be produced convex shapes where the erosional base descended topographically (by deep impact crater or deep outflow channel formation

  11. NASA's Terra spacecraft is prepared for encapsulation before launch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    NASA's Terra spacecraft (right) is prepared for encapsulation in the rocket faring (left) before launch at Vandenberg AFB, Calif. The faring displays a logo of the many science instruments that make up Terra. The spacecraft's launch aboard a Lockheed Martin Atlas IIAS rocket is scheduled for Dec. 16 from Space Launch Complex 3 East at Vandenberg. Terra comprises five state-of-the- art sets of instruments that will collect data for continuous, long-term records of the state of Earth's land, oceans and atmosphere. Together with data from other satellite systems launched by NASA and other countries, Terra will inaugurate a new self-consistent data record that will be gathered over the next 15 years. From an altitude of 438 miles, Terra will circle the Earth 16 times a day from pole to pole (98 degree inclination), crossing the equator at 10:30 a.m. The five Terra instruments will operate by measuring sunlight reflected by the Earth and heat emitted by the Earth.

  12. Terra - 15 Years as the Earth Observing System Flagship Observatory

    NASA Astrophysics Data System (ADS)

    Thome, K. J.

    2014-12-01

    Terra marks its 15th year on orbit with an array of accomplishments and the potential to do much more. Efforts continue to extend the Terra data record to make its data more valuable by creating a record length to examine interannual variability, observe trends on the decadal scale, and gather statistics relevant to climate metrics. Continued data from Terra's complementary instruments will play a key role in creating the data record needed for scientists to develop an understanding of our climate system. Terra's suite of instruments: ASTER (contributed by the Japanese Ministry of Economy and Trade and Industry with a JPL-led US Science Team), CERES (NASA LaRC - PI), MISR (JPL - PI), MODIS (NASA GSFC), and MOPITT (sponsored by Canadian Space Agency with NCAR-led Science Team) are providing an unprecedented 81 core data products. The annual demand for Terra data remains with >120 million files distributed in 2011 and >157 million in 2012. More than 1,100 peer-reviewed publications appeared in 2012 using Terra data bringing the lifetime total >7,600. Citation numbers of 21,000 for 2012 and over 100,000 for the mission's lifetime. The power of Terra is in the high quality of the data calibration, sensor characterization, and the complementary nature of the instruments covering a range of scientific measurements as well as scales. The broad range of products enable the community to provide answers to the overarching question, "How is the Earth changing and what are the consequences for life on Earth?" Terra continues to provide data that: (1) Extend the baseline of morning-orbit collections; (2) Enable comparison of measurements acquired from past high-impact events; (3) Add value to recently-launched and soon-to-be launched missions, and upcoming field programs. Terra data continue to support monitoring and relief efforts for natural and man-made disasters that involve U.S. interests. Terra also contributes to Applications Focus Areas supporting the U.S. National

  13. Sulfates on Mars: Indicators of Aqueous Processes

    NASA Technical Reports Server (NTRS)

    Bishop, Janice L.; Lane, Melissa D.; Dyar, M. Darby; Brown, Adrian J.

    2006-01-01

    Recent analyses by MER instruments at Meridiani Planum and Gusev crater and the OMEGA instrument on Mars Express have provided detailed information about the presence of sulfates on Mars [1,2,3]. We are evaluating these recent data in an integrated multi-disciplinary study of visible-near-infrared, mid-IR and Mossbauer spectra of several sulfate minerals and sulfate-rich analog sites. Our analyses suggest that hydrated iron sulfates may account for features observed in Mossbauer and mid-IR spectra of Martian soils [4]. The sulfate minerals kieserite, gypsum and other hydrated sulfates have been identified in OMEGA spectra in the layered terrains in Valles Marineris and Terra Meridiani [2]. These recent discoveries emphasize the importance of studying sulfate minerals as tracers of aqueous processes. The sulfate-rich rock outcrops observed in Meridiani Planum may have formed in an acidic environment similar to acid rock drainage environments on Earth [5]. Because microorganisms typically are involved in the oxidation of sulfides to sulfates in terrestrial sites, sulfate-rich rock outcrops on Mars may be a good location to search for evidence of past life on that planet. Whether or not life evolved on Mars, following the trail of sulfate minerals will lead to a better understanding of aqueous processes and chemical weathering.

  14. Waters and desalination programs of Saudi Arabia

    SciTech Connect

    Wojcik, C.K.; Maadhah, A.G.

    1981-07-01

    Saudi Arabia is an arid desert country without rivers or sweet-water lakes. It does, however, have large amounts of ground water and seawater. These waters must be desalted by some means in order to make them potable. The most frequently used methods for that purpose are: multistage flash (MSF) evaporation, reverse osmosis (RO), and electrodialysis (ED). Because of rapid industrialization of the country, the demand for fresh water has been growing steadily. This, in turn, has resulted in a spectacular growth of the water-desalination industry. This paper discusses the availability and properties of the waters. It gives a detailed description of the major accomplishments and of the ongoing and future programs in the field of water desalination in Saudi Arabia. 14 references, 6 figures, 8 tables.

  15. Mars habitat

    NASA Technical Reports Server (NTRS)

    Ayers, Dale; Barnes, Timothy; Bryant, Woody; Chowdhury, Parveen; Dillard, Joe; Gardner, Vernadette; Gregory, George; Harmon, Cheryl; Harrell, Brock; Hilton, Sherrill

    1991-01-01

    The objective of this study is to develop a conceptual design for a permanently manned, self-sustaining Martian facility, to accommodate a crew of 20 people. The goal is to incorporate the major functions required for long term habitation in the isolation of a barren planet into a thriving ecosystem. These functions include living, working, service, and medical facilities as well as a green house. The main design task was to focus on the internal layout while investigating the appropriate structure, materials, and construction techniques. The general concept was to create a comfortable, safe living environment for the crew members for a stay of six to twelve months on Mars. Two different concepts were investigated, a modular assembly reusable structure (MARS) designated Lavapolis, and a prefabricated space frame structure called Hexamars. Both models take into account factors such as future expansion, radiation shielding, and ease of assembly.

  16. Aedes mosquito species in western Saudi Arabia.

    PubMed

    Alikhan, Masroor; Al Ghamdi, Khalid; Mahyoub, Jazem Abdullah

    2014-01-01

    The Aedes Meigen (Diptera: Culicidae) mosquito species populations in the western region of Saudi Arabia, especially in and around Jeddah, are increasing, therefore increasing susceptibility of humans to the dengue virus. An extensive survey was carried out for one year, and four species were identified with the help of different pictorial keys available. The identification was based on morphological characteristics of adult female Aedes mosquitoes. PMID:25373216

  17. Dust Storm, Red Sea and Saudi Arabia

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Outlined against the dark blue water of the Red Sea, a prominent dust storm is making its way across the Red Sea into Saudi Arabia (22.0N, 39.0E) between the Islamic holy cities of Medinah and Mecca. Funneled through a gap in the coastal ranges of southern Sudan near the Ethiopian border, dust storms frequently will blow counter to the prevailing tropical easterly winds of the region.

  18. Telomeric repeat-containing RNA (TERRA) constitutes a nucleoprotein component of extracellular inflammatory exosomes

    PubMed Central

    Wang, Zhuo; Deng, Zhong; Dahmane, Nadia; Tsai, Kevin; Wang, Pu; Williams, Dewight R.; Kossenkov, Andrew V.; Showe, Louise C.; Zhang, Rugang; Huang, Qihong; Conejo-Garcia, José R.; Lieberman, Paul M.

    2015-01-01

    Telomeric repeat-containing RNA (TERRA) has been identified as a telomere-associated regulator of chromosome end protection. Here, we report that TERRA can also be found in extracellular fractions that stimulate innate immune signaling. We identified extracellular forms of TERRA in mouse tumor and embryonic brain tissue, as well as in human tissue culture cell lines using RNA in situ hybridization. RNA-seq analyses revealed TERRA to be among the most highly represented transcripts in extracellular fractions derived from both normal and cancer patient blood plasma. Cell-free TERRA (cfTERRA) could be isolated from the exosome fractions derived from human lymphoblastoid cell line (LCL) culture media. cfTERRA is a shorter form (∼200 nt) of cellular TERRA and copurifies with CD63- and CD83-positive exosome vesicles that could be visualized by cyro-electron microscopy. These fractions were also enriched for histone proteins that physically associate with TERRA in extracellular ChIP assays. Incubation of cfTERRA-containing exosomes with peripheral blood mononuclear cells stimulated transcription of several inflammatory cytokine genes, including TNFα, IL6, and C-X-C chemokine 10 (CXCL10) Exosomes engineered with elevated TERRA or liposomes with synthetic TERRA further stimulated inflammatory cytokines, suggesting that exosome-associated TERRA augments innate immune signaling. These findings imply a previously unidentified extrinsic function for TERRA and a mechanism of communication between telomeres and innate immune signals in tissue and tumor microenvironments. PMID:26578789

  19. BOOK REVIEW: European Perceptions of Terra Australis

    NASA Astrophysics Data System (ADS)

    Sterken, Christiaan

    2012-12-01

    Terra Australis - the southern land - has been one of the most widespread concepts in European geography from the sixteenth to the eighteenth century. This book comprises a set of 14 interdisciplinary scholarly contributions that deal with personal perceptions of Terra Australis by cartographers and explorers, and with putting these perceptions in their historical and cultural environments. This book seems, at a first glance, to be very remote from astronomy - and even from the history of astronomy - however, as it also offers an excellent background to Captain James Cook's second voyage to observe the 1769 transit of Venus from Tahiti, it definitely is a work of truly interdisciplinary character. Cook's voyages, in fact, became a model in which key scientists of many nationalities and disciplines traveled together on ships. In these voyages, art, science, technology and political power were centralised and united. The chapters range across history, the visual arts, literature, popular culture, technology, politics and science. Issues of scientific reasoning are raised in the description of how people did think about the south before there even existed a perception of the unknown land - quite comparable to how ancient and early-modern astronomers had their thought about cosmology even before any observational data were available. Several early map systems - like the zonal and T-O maps (medieval world maps with the letter T inside an O representing the lands inside a circle of oceans) - are described, and the description of Roman geography shows the amazing fact that theory and practice were not unified, and existed independently of each other insofar that a real paradox between theory and observation had persisted for a very long time. The maps and charts also exemplify the long-lasting consequences of early modern copy-paste practice: navigators copied original sketch charts of coasts that were previously unknown to them, herewith committing many translation and

  20. Search for Chemically Bound Water in the Surface Layer of Mars Based on HEND/Mars Odyssey Data

    NASA Technical Reports Server (NTRS)

    Basilevsky, A. T.; Litvak, M. L.; Mitrofanov, I. G.; Boynton, W.; Saunders, R. S.

    2003-01-01

    This study is emphasized on search for signatures of chemically bound water in surface layer of Mars based on data acquired by High Energy Neutron Detector (HEND) which is part of the Mars Odyssey Gamma Ray Spectrometer (GRS). Fluxes of epithermal (probe the upper 1-2 m) and fast (the upper 20-30 cm) neutrons, considered in this work, were measured since mid February till mid June 2002. First analysis of this data set with emphasis of chemically bound water was made. Early publications of the GRS results reported low neutron flux at high latitudes, interpreted as signature of ground water ice, and in two low latitude areas: Arabia and SW of Olympus Mons (SWOM), interpreted as 'geographic variations in the amount of chemically and/or physically bound H2O and or OH...'. It is clear that surface materials of Mars do contain chemically bound water, but its amounts are poorly known and its geographic distribution was not analyzed.

  1. Synergism of MODIS Aerosol Remote Sensing from Terra and Aqua

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles; Kaufman, Yoram J.; Remer, Lorraine A.

    2003-01-01

    The MODerate-resolution Imaging Spectro-radiometer (MODIS) sensors, aboard the Earth Observing System (EOS) Terra and Aqua satellites, are showing excellent competence at measuring the global distribution and properties of aerosols. Terra and Aqua were launched on December 18, 1999 and May 4, 2002 respectively, with daytime equator crossing times of approximately 10:30 am and 1:30 pm respectively. Several aerosol parameters are retrieved at 10-km spatial resolution from MODIS daytime data over land and ocean surfaces. The parameters retrieved include: aerosol optical thickness (AOT) at 0.47, 0.55 and 0.66 micron wavelengths over land, and at 0.47, 0.55, 0.66, 0.87, 1.2, 1.6, and 2.1 microns over ocean; Angstrom exponent over land and ocean; and effective radii, and the proportion of AOT contributed by the small mode aerosols over ocean. Since the beginning of its operation, the quality of Terra-MODIS aerosol products (especially AOT) have been evaluated periodically by cross-correlation with equivalent data sets acquired by ground-based (and occasionally also airborne) sunphotometers, particularly those coordinated within the framework of the AErosol Robotic NETwork (AERONET). Terra-MODIS AOT data have been found to meet or exceed pre-launch accuracy expectations, and have been applied to various studies dealing with local, regional, and global aerosol monitoring. The results of these Terra-MODIS aerosol data validation efforts and studies have been reported in several scientific papers and conferences. Although Aqua-MODIS is still young, it is already yielding formidable aerosol data products, which are also subjected to careful periodic evaluation similar to that implemented for the Terra-MODIS products. This paper presents results of validation of Aqua-MODIS aerosol products with AERONET, as well as comparative evaluation against corresponding Terra-MODIS data. In addition, we show interesting independent and synergistic applications of MODIS aerosol data from

  2. Effect of MODIS Terra Radiometric Calibration Improvements on Collection 6 Deep Blue Aerosol Products: Validation and Terra/Aqua Consistency

    NASA Technical Reports Server (NTRS)

    Sayer, A. M.; Hsu, N. C.; Bettenhausen, C.; Jeong, M.-J.; Meister, G.

    2015-01-01

    The Deep Blue (DB) algorithm's primary data product is midvisible aerosol optical depth (AOD). DB applied to Moderate Resolution Imaging Spectroradiometer (MODIS) measurements provides a data record since early 2000 for MODIS Terra and mid-2002 for MODIS Aqua. In the previous data version (Collection 5, C5), DB production from Terra was halted in 2007 due to sensor degradation; the new Collection 6 (C6) has both improved science algorithms and sensor radiometric calibration. This includes additional calibration corrections developed by the Ocean Biology Processing Group to address MODIS Terra's gain, polarization sensitivity, and detector response versus scan angle, meaning DB can now be applied to the whole Terra record. Through validation with Aerosol Robotic Network (AERONET) data, it is shown that the C6 DB Terra AOD quality is stable throughout the mission to date. Compared to the C5 calibration, in recent years the RMS error compared to AERONET is smaller by approximately 0.04 over bright (e.g., desert) and approximately 0.01-0.02 over darker (e.g., vegetated) land surfaces, and the fraction of points in agreement with AERONET within expected retrieval uncertainty higher by approximately 10% and approximately 5%, respectively. Comparisons to the Aqua C6 time series reveal a high level of correspondence between the two MODIS DB data records, with a small positive (Terra-Aqua) average AOD offset <0.01. The analysis demonstrates both the efficacy of the new radiometric calibration efforts and that the C6 MODIS Terra DB AOD data remain stable (to better than 0.01 AOD) throughout the mission to date, suitable for quantitative scientific analyses.

  3. Effect of MODIS Terra radiometric calibration improvements on Collection 6 Deep Blue aerosol products: Validation and Terra/Aqua consistency

    NASA Astrophysics Data System (ADS)

    Sayer, A. M.; Hsu, N. C.; Bettenhausen, C.; Jeong, M.-J.; Meister, G.

    2015-12-01

    The Deep Blue (DB) algorithm's primary data product is midvisible aerosol optical depth (AOD). DB applied to Moderate Resolution Imaging Spectroradiometer (MODIS) measurements provides a data record since early 2000 for MODIS Terra and mid-2002 for MODIS Aqua. In the previous data version (Collection 5, C5), DB production from Terra was halted in 2007 due to sensor degradation; the new Collection 6 (C6) has both improved science algorithms and sensor radiometric calibration. This includes additional calibration corrections developed by the Ocean Biology Processing Group to address MODIS Terra's gain, polarization sensitivity, and detector response versus scan angle, meaning DB can now be applied to the whole Terra record. Through validation with Aerosol Robotic Network (AERONET) data, it is shown that the C6 DB Terra AOD quality is stable throughout the mission to date. Compared to the C5 calibration, in recent years the RMS error compared to AERONET is smaller by ˜0.04 over bright (e.g., desert) and ˜0.01-0.02 over darker (e.g., vegetated) land surfaces, and the fraction of points in agreement with AERONET within expected retrieval uncertainty higher by ˜10% and ˜5%, respectively. Comparisons to the Aqua C6 time series reveal a high level of correspondence between the two MODIS DB data records, with a small positive (Terra-Aqua) average AOD offset <0.01. The analysis demonstrates both the efficacy of the new radiometric calibration efforts and that the C6 MODIS Terra DB AOD data remain stable (to better than 0.01 AOD) throughout the mission to date, suitable for quantitative scientific analyses.

  4. Identification of New Genomospecies in the Mycobacterium terrae Complex

    PubMed Central

    Ngeow, Yun Fong; Wong, Yan Ling; Tan, Joon Liang; Hong, Kar Wai; Ng, Hien Fuh; Ong, Bee Lee; Chan, Kok Gan

    2015-01-01

    Members of the Mycobacterium terrae complex are slow-growing, non-chromogenic acid-fast bacilli found in the natural environment and occasionally in clinical material. These genetically closely-related members are difficult to differentiate by conventional phenotypic and molecular tests. In this paper we describe the use of whole genome data for the identification of four strains genetically similar to Mycobacterium sp. JDM601, a newly identified member of the M. terrae complex. Phylogenetic information from the alignment of genome-wide orthologous genes and single nucleotide polymorphisms show consistent clustering of the four strains together with M. sp. JDM601 into a distinct clade separate from other rapid and slow growing mycobacterial species. More detailed inter-strain comparisons using average nucleotide identity, tetra-nucleotide frequencies and analysis of synteny indicate that our strains are closely related to but not of the same species as M. sp. JDM601. Besides the 16S rRNA signature described previously for the M. terrae complex, five more hypothetical proteins were found that are potentially useful for the rapid identification of mycobacterial species belonging to the M. terrae complex. This paper illustrates the versatile utilization of whole genome data for the delineation of new bacterial species and introduces four new genomospecies to add to current members in the M. terrae complex. PMID:25830768

  5. NASA's Terra spacecraft is prepared for encapsulation before launch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The rocket faring (left) displays a logo of the many science instruments that make up NASA's Terra spacecraft (background). When fully assembled, Terra will be encapsulated in the faring before launch, scheduled for Dec. 16 aboard a Lockheed Martin Atlas IIAS rocket from Space Launch Complex 3 East at Vandenberg AFB, Calif. Terra comprises five state-of-the-art sets of instruments that will collect data for continuous, long-term records of the state of Earth's land, oceans and atmosphere. Together with data from other satellite systems launched by NASA and other countries, it will inaugurate a new self-consistent data record that will be gathered over the next 15 years. From an altitude of 438 miles, Terra will circle the Earth 16 times a day from pole to pole (98 degree inclination), crossing the equator at 10:30 a.m. The five Terra instruments will operate by measuring sunlight reflected by the Earth and heat emitted by the Earth.

  6. Demographic perspectives on Saudi Arabia's development.

    PubMed

    Looney, R E

    1985-06-01

    Demographic movements likely to be taking place in Saudi Arabia were hypothesized on the basis of general knowledge. The discussion reports on population size, general Arab demographic patterns, general determinants of fertility, Arab fertility patterns, Saudi fertility patterns, mortality in general, mortality in the Middle East, mortality in Saudi Arabia, Saudi Arabian population growth, immigration, the changing composition of the work force, and third plan targets. Some doubt exists as to the size of Saudi Arabia's population, but there is little question that the total is growing rapidly. This expansion is taking place through stepped up immigration and a relatively high natural growth of indigenous Saudis, but statistics on population size, structure, and on the number of births and deaths leaves the magnitude of a number of important demographic trends in doubt. Yet, considerable evidence exists that several of the Arab countries in the region with fairly good demographic data are likely to have similar demographic patterns. In depth analysis of the demographic dynamics of these countries, particularly Jordan and Kuwait, identified several common elements bearing on several key parameters. Using what Saudi data is available and making comparisons with these neighboring countries, one can, based on expected levels of birth and death rates, indirectly infer the natural growth of Saudi Arabia's population. With several notable exceptions, Saudi Arabia's demographic patterns show a marked similarity to those experienced in the region as a whole. The average rate of population growth in both Saudi Arabia and the Arab region is about 3% a year and in both instances fertility rates are high. The demographic structure of these countries is characterized by the youthfulness of the population. In most of the Arab countries, the population aged 15 years or under accounts for over 48% of the population. The rate of the economically active population is low, ranging from

  7. NASA Mars Conference

    SciTech Connect

    Reiber, D.B.

    1988-01-01

    Papers about Mars and Mars exploration are presented, covering topics such as Martian history, geology, volcanism, channels, moons, atmosphere, meteorology, water on the planet, and the possibility of life. The unmanned exploration of Mars is discussed, including the Phobos Mission, the Mars Observer, the Mars Aeronomy Observer, the seismic network, Mars sample return missions, and the Mars Ball, an inflatable-sectored-tire rover concept. Issues dealing with manned exploration of Mars are examined, such as the reasons for exploring Mars, mission scenarios, a transportation system for routine visits, technologies for Mars expeditions, the human factors for Mars missions, life support systems, living and working on Mars, and the report of the National Commission on Space.

  8. Women and Education in Saudi Arabia: Challenges and Achievements

    ERIC Educational Resources Information Center

    Hamdan, Amani

    2005-01-01

    The historical socio-economic and political conditions of Saudi Arabia are an essential aspect of understanding a woman's position in Saudi society. The persistence of women's exclusion from public life in contemporary Saudi Arabia is one of the most heated debates not only among Muslims but also worldwide, as Saudi society comes under more and…

  9. Special Education in Saudi Arabia: Challenges, Perspectives, Future Possibilities

    ERIC Educational Resources Information Center

    Alquraini, Turki

    2011-01-01

    This paper provides a brief background of the education system in Saudi Arabia and current special education services and programs for students with disabilities. Additionally, this paper presents the findings of some studies that examined teachers' perspectives regarding the inclusion of students with disabilities. As Saudi Arabia continues its…

  10. Mars @ ASDC

    NASA Astrophysics Data System (ADS)

    Carraro, Francesco

    "Mars @ ASDC" is a project born with the goal of using the new web technologies to assist researches involved in the study of Mars. This project employs Mars map and javascript APIs provided by Google to visualize data acquired by space missions on the planet. So far, visualization of tracks acquired by MARSIS and regions observed by VIRTIS-Rosetta has been implemented. The main reason for the creation of this kind of tool is the difficulty in handling hundreds or thousands of acquisitions, like the ones from MARSIS, and the consequent difficulty in finding observations related to a particular region. This led to the development of a tool which allows to search for acquisitions either by defining the region of interest through a set of geometrical parameters or by manually selecting the region on the map through a few mouse clicks The system allows the visualization of tracks (acquired by MARSIS) or regions (acquired by VIRTIS-Rosetta) which intersect the user defined region. MARSIS tracks can be visualized both in Mercator and polar projections while the regions observed by VIRTIS can presently be visualized only in Mercator projection. The Mercator projection is the standard map provided by Google. The polar projections are provided by NASA and have been developed to be used in combination with APIs provided by Google The whole project has been developed following the "open source" philosophy: the client-side code which handles the functioning of the web page is written in javascript; the server-side code which executes the searches for tracks or regions is written in PHP and the DB which undergoes the system is MySQL.