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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Mars Elysium Basin - Geologic/volumetric analysis of a young lake and exobiologic implications

Geologic, physiographic, and topographic data on the Elysium Basin on the Martial lowland plains are used to determine the former volume of water in the basin and the sources of this water. The maximum extent of the paleolake was estimated to be about 2,000,000 sq km, with a water volume of 850,000 cu km or more, supplied to the basin from many sources in the highlands via inflow channels. The climatic and biological implications that the Elysium-Basin sea or lake might have had are discussed.

Scott, D. H.↗
NASA NTRS1991

Venus mapping

Semicontrolled image mosaics of Venus, based on Magellan data, are being compiled at 1:50,000,000, 1:10,000,000, 1:5,000,000, and 1:1,000,000 scales to support the Magellan Radar Investigator (RADIG) team. The mosaics are semicontrolled in the sense that data gaps were not filled and significant cosmetic inconsistencies exist. Contours are based on preliminary radar altimetry data that is subjected to revision and improvement. Final maps to support geologic mapping and other scientific investigations, to be compiled as the dataset becomes complete, will be sponsored by the Planetary Geology and Geophysics Program and/or the Venus Data Analysis Program. All maps, both semicontrolled and final, will be published as I-maps by the United States Geological Survey. All of the mapping is based on existing knowledge of the spacecraft orbit; photogrammetric triangulation, a traditional basis for geodetic control on planets where framing cameras were used, is not feasible with the radar images of Venus, although an eventual shift of coordinate system to a revised spin-axis location is anticipated. This is expected to be small enough that it will affect only large-scale maps.

Batson, R. M.↗
NASA NTRS1976

Geochemistry

The most effective strategy for the geochemical study of a planet is to proceed systematically with the mineralogical and chemical characterization of its materials in accordance with geologically determined priorities. It is insufficient merely to analyze chemically the surface rocks. To appreciate the meaning of a chemical analysis, some assessment must be made of the geologic history of the sample - what its source and mode of origin are and what processes have operated upon the sample to cause chemical fractionation. Determination of mineralogy, texture, lithology, and other properties of the rock that might be relevant to origin is, therefore, necessary.

Carr, M. H.↗
NASA NTRS1995

Aerolian erosion, transport, and deposition of volcaniclastic sands among the shifting sand dunes, Christmas Lake Valley, Oregon: TIMS image analysis

Remote sensing is a tool that, in the context of aeolian studies, offers a synoptic view of a dune field, sand sea, or entire desert region. Blount et al. (1990) presented one of the first studies demonstrating the power of multispectral images for interpreting the dynamic history of an aeolian sand sea. Blount's work on the Gran Desierto of Mexico used a Landsat TM scene and a linear spectral mixing model to show where different sand populations occur and along what paths these sands may have traveled before becoming incorporated into dunes. Interpretation of sand transport paths and sources in the Gran Desierto led to an improved understanding of the origin and Holocene history of the dunes. With the anticipated advent of the EOS-A platform and ASTER thermal infrared capability in 1998, it will become possible to look at continental sand seas and map sand transport paths using 8-12 mu m bands that are well-suited to tracking silicate sediments. A logical extension of Blount's work is to attempt a similar study using thermal infrared images. One such study has already begun by looking at feldspar, quartz, magnetite, and clay distributions in the Kelso Dunes of southern California. This paper describes the geology and application of TIMS image analysis of a less-well known Holocene dune field in south central Oregon using TIMS data obtained in 1991.

Edgett, Kenneth S.↗
NASA NTRS1975

Computer-aided analysis of Skylab multispectral scanner data in mountainous terrain for land use, forestry, water resource, and geologic applications

The author has identified the following significant results. One of the most significant results of this Skylab research involved the geometric correction and overlay of the Skylab multispectral scanner data with the LANDSAT multispectral scanner data, and also with a set of topographic data, including elevation, slope, and aspect. The Skylab S192 multispectral scanner data had distinct differences in noise level of the data in the various wavelength bands. Results of the temporal evaluation of the SL-2 and SL-3 photography were found to be particularly important for proper interpretation of the computer-aided analysis of the SL-2 and SL-3 multispectral scanner data. There was a quality problem involving the ringing effect introduced by digital filtering. The modified clustering technique was found valuable when working with multispectral scanner data involving many wavelength bands and covering large geographic areas. Analysis of the SL-2 scanner data involved classification of major cover types and also forest cover types. Comparison of the results obtained wth Skylab MSS data and LANDSAT MSS data indicated that the improved spectral resolution of the Skylab scanner system enabled a higher classification accuracy to be obtained for forest cover types, although the classification performance for major cover types was not significantly different.

Hoffer, R. M.↗
NASA NTRS1995

Global Stratigraphy of Venus: Analysis of a Random Sample of Thirty-Six Test Areas

The age relations between 36 impact craters with dark paraboloids and other geologic units and structures at these localities have been studied through photogeologic analysis of Magellan SAR images of the surface of Venus. Geologic settings in all 36 sites, about 1000 x 1000 km each, could be characterized using only 10 different terrain units and six types of structures. These units and structures form a major stratigraphic and geologic sequence (from oldest to youngest): (1) tessera terrain; (2) densely fractured terrains associated with coronae and in the form of remnants among plains; (3) fractured and ridged plains and ridge belts; (4) plains with wrinkle ridges; (5) ridges associated with coronae annulae and ridges of arachnoid annulae which are contemporary with wrinkle ridges of the ridged plains; (6) smooth and lobate plains; (7) fractures of coronae annulae, and fractures not related to coronae annulae, which disrupt ridged and smooth plains; (8) rift-associated fractures; and (9) craters with associated dark paraboloids, which represent the youngest 1O% of the Venus impact crater population (Campbell et al.), and are on top of all volcanic and tectonic units except the youngest episodes of rift-associated fracturing and volcanism; surficial streaks and patches are approximately contemporary with dark-paraboloid craters. Mapping of such units and structures in 36 randomly distributed large regions (each approximately 10(exp 6) sq km) shows evidence for a distinctive regional and global stratigraphic and geologic sequence. On the basis of this sequence we have developed a model that illustrates several major themes in the history of Venus. Most of the history of Venus (that of its first 80% or so) is not preserved in the surface geomorphological record. The major deformation associated with tessera formation in the period sometime between 0.5-1.0 b.y. ago (Ivanov and Basilevsky) is the earliest event detected. In the terminal stages of tessera fon-nation, extensive parallel linear graben swarms representing a change in the style of deformation from shortening to extension were formed on the tessera and on some volcanic plains that were emplaced just after, and perhaps also during the latter stages of the major compressional phase of tessera emplacement. Our stratigraphic analyses suggest that following tessera formation, extensive volcanic flooding resurfaced at least 85% of the planet in the form of the presently-ridged and fractured plains. Several lines of evidence favor a high flux in the post-tessera period but we have no independent evidence for the absolute duration of ridged plains emplacement. During this time, the net state of stress in the lithosphere apparently changed from extensional to compressional, first in the form of extensive ridge belt development, followed by the formation of extensive wrinkle ridges on the flow units. Subsequently, there occurred local emplacement of smooth and lobate plains units which are presently essentially undefortned. The major events in the latest 10% of the presently preserved history of Venus (less than 50 m.y. ago) are continued rifting and some associated volcanism, and the redistribution of eolian material largely derived from impact crater deposits.

Basilevsky, Alexander T.↗
NASA NTRS1974

Contribution of space platforms to a ground and airborne remote sensing programme over active Italian volcanoes

The author has identified the following significant results. A method has been suggested for the forecasting of the lateral eruptions of Mount Etna, through the multispectral analysis of the vegetation behavior. Unknown geological lineaments which seem to be related to deep crustal movements have been discovered using the ERTS-1 imagery. Results in the geological field were obtained in the study of the general structure of the Alpine range. In the field of official vegetation classification, ERTS-1 images were used for a preliminary study of rice fields in northern Italy. Very good experimental results have been obtained using the Skylab multispectral photographs. In the field of hydrogeology and soil type discrimination discoveries of unknown paleoriver beds have been made in the northeastern part of the Po Valley using the multispectral imagery of SL3. The superior resolution of Skylab was a fundamental element for the success of this investigation.

Cassinis, R.↗
NASA NTRS1980

Preliminary analysis of the potential of LANDSAT imagery to study desertification

The use of LANDSAT imagery to define and delimit areas under process of desertification was investigated. Imagery for two different years (1973 and 1978) and two different seasons (dry and rainy seasons in 1976), were used to identify terrain morphology and vegetation cover. The analysis of LANDSAT interpretation, combined with geological and soil information obtained from published literature, allowed the identification of eleven ecological units which were classified corresponding to the degree of the Xique Xique region of Rio Sao Francisco.

Dejesusparada, N.↗
NASA NTRS1983

Inventory and analysis of rangeland resources of the state land block on Parker Mountain, Utah

High altitude color infrared (CIR) photography was interpreted to provide an 1:24,000 overlay to U.S.G.S. topographic maps. The inventory and analysis of rangeland resources was augmented by the digital analysis of LANDSAT MSS data. Available geology, soils, and precipitation maps were used to sort out areas of confusion on the CIR photography. The map overlay from photo interpretation was also prepared with reference to print maps developed from LANDSAT MSS data. The resulting map overlay has a high degree of interpretive and spatial accuracy. An unacceptable level of confusion between the several sagebrush types in the MSS mapping was largely corrected by introducing ancillary data. Boundaries from geology, soils, and precipitation maps, as well as field observations, were digitized and pixel classes were adjusted according to the location of pixels with particular spectral signatures with respect to such boundaries. The resulting map, with six major cover classes, has an overall accuracy of 89%. Overall accuracy was 74% when these six classes were expanded to 20 classes.

Jaynes, R. A.↗
NASA NTRS1984

Topography on Ganymede derived from photoclinometry

A fundamental limitation in the quantitative analysis of planetary geomorphology and structural geology results from the absense of topographic data. Among the studies that might be addressed, were such data available, are volumetric and slope relationships of Ionian volcanics, fracture and annealing processes in icy crusts on Europa and Ganymede, and evaluation of viscous relaxation as a means of degrading landforms on Europea, Ganymede, and Callisto. A technique for acquiring topographic data on the Galilean satellites using photoclinometry was developed and applied.

Danielson, G. E.↗
NASA NTRS1983

Thermal inertia mapping - A promising new tool for mineral exploration

The Heat Capacity Mapping Mission (HCMM) is a NASA-sponsored program designed to acquire day visible and day and night thermal IR imagery from a satellite launched on April 26, 1978 into a near polar orbit at 620 km altitude. The data are used to produce temperature difference (12 or 36 hour interval) and apparent thermal inertia (ATI) images or numerical data sets for selected areas within much of North America, Europe, North Africa, and Australia. These data are being applied to rock type discrimination, soil moisture detection, assessment of vegetation states, thermal current monitoring in water bodies, urban heat island analysis and other multidisciplinary studies. Key geological results include (1) groups of dissimilar rock materials and some individual rock types can be separated and sometimes identified by their satellite-determined thermal inertias (dependent on their albedos, densities, and conductivities), (2) large lineaments (including some faults) are often recognized by their thermal signatures (may relate to moisture content and/or reduced bulk density), and (3) visually striking expressions of geomorphic units (types) at a regional scale are especially enhanced in the night IR imagery.

Short, N. M.↗
NASA NTRS1986

The fossil record of evolution: Data on diversification and extinction

Synoptic studies of the fossil record of complex life on Earth indicate increasingly that extinction, and especially mass extinction, were extremely important driving forces in the history of life. Analysis of a new compilation of geologic ranges for 25,000 genera of marine animals suggests that extinction events were much more frequent in occurrence and variable in magnitude than previously suspected. At least 30 well documented and potential mass extinctions were identified in the dataset. The most recent event, distributed over 260 to 0 ma. exhibit a stationary periodicity of 26.1 + or - 1 ma, implicating a cosmological forcing mechanism. Earlier events, especially in the 575 to 450 ma interval, are more frequent, possibly indicating either a breakdown of periodicity in the more distant past; and as yet undemonstrated diminution of the period length; or frequent aperiodic terrestrial perturbations of a less stable biota superimposed upon the cosmological periodicity.

Sepkoski, J. J., Jr.↗
NASA NTRS1988

The Shuttle Imaging Radar B (SIR-B) experiment report

The primary objective of the SIR-B experiment was to acquire multiple-incidence-angle radar imagery of a variety of Earth's surfaces to better understand the effects of imaging geometry on radar backscatter. A complementary objective was to map extensive regions of particular interest. Under these broad objectives, many specific scientific experiments were defined by the 43 SIR-B Science Team members, including studies in the area of geology, vegetation, radar penetration, oceanography, image analysis, and calibration technique development. Approximately 20 percent of the planned digital data were collected, meeting 40 percent of the scientific objectives. This report is an overview of the SIR-B experiment and includes the science investigations, hardware design, mission scenario, mission operations, events of the actual missions, astronaut participation, data products (including auxiliary data), calibrations, and a summary of the actual coverage. Also included are several image samples.

Cimino, Jo Bea↗
NASA NTRS1990

Terrestrial-Imaging Spectroscopy

Report reviews history and state of art of terrestrial imaging spectroscopy. Discusses history, design, and performance of Airborne Imaging Spectrometer (AIS), which is pioneering sensor for terrestrial high-resolution remote sensing. Also discusses recent developments described in literature of imaging spectroscopy from three points of view: techniques for handling and analysis of spectral-image data, geological research, and botanical research. This field encompasses use of airborne and spaceborne imaging spectrometers to generate specialized maps for use in agriculture, geology, ecology, and related disciplines.

Vane, Gregg A.↗
NASA NTRS1993

Chronology, eruption duration, and atmospheric contribution of the Martian volcano Apollinaris Patera

Results are presented of an investigation of the geology, physical properties, and topography of Apollinaris Patera which was performed on the basis of geologic mapping, thermal inertia measurements, and analysis of the color (visual wavelengths) of this Martian volcano. Initially, the main edifice was formed over a period of about 10 exp 7 yr, and then the volcano experienced a period of quiescence during which the basal scarp formed and the valleys were incised in the main flanks. Activity at the summit formed the present large outer caldera and floor materials. After, or during late stages of outer calder activity, the materials that formed the fan were erupted over 10,000 yr. After emplacement of the fan materials, the smaller, inner caldera and associated floor materials formed over an unconstrained time period. Morphologic analysis suggests that a significant portion of the main edifice is composed of poorly to nonwelded pyroclastic deposits, possibly including a phreatomagmatic component.

Robinson, Mark S.↗
NASA NTRS1994

Spectroscopy of Mars from 2.04 to 2.44 micrometers during the 1993 opposition: absolute calibration and atmospheric vs mineralogic origin of narrow absorption features

We present moderate-resolution (lambda/delta lambda = 300 to 370) reflectance spectra of Mars from 2.04 to 2.44 micrometers that were obtained at UKIRT during the 1993 opposition. Seven narrow absorption features were detected and found to have a Mars origin. By comparison with solar and Mars atmospheric spectra, five of these features were attributed all or in part to Mars atmospheric CO2 or CO(2.052 +/- 0.003, 2.114 +/- 0.002, 2.150 +/- 0.003, 2.331 +/- 0.001, and 2.357 +/- 0.002 micrometers). Two of the bands (2.331 +/- 0.001 and 2.357 +/- 0.002 micrometers) appear to have widths and depths that are consistent with additional, nonatmospheric absorptions, although a solar contribution cannot be entirely ruled out. Two other weak bands centered at 2.278 +/- 0.002 and 2.296 +/- 0.002 micrometers may be at least partially mineralogic in origin. The data provide no conclusive identification of the mineralogy responsible for these absorption features. However, examination of terrestrial spectral libraries and previous moderate spectral resolution mineral studies indicates that the most likely origin of these features is either (bi)carbonate or (bi)sulfate anions in framework silicates or (Fe, Mg)-OH bonds in sheet silicates. If the bands are caused by phyllosilicate minerals, then an explanation must be found for the extremely narrow widths of the cation-OH features in the Mars spectra as compared to terrestrial minerals.

Mars↗
NASA NTRS2004

Life Detection on the Early Earth

Finding evidence for first the existence, and then the nature of life on the early Earth or early Mars requires both the recognition of subtle biosignatures and the elimination of false positives. The history of the search for fossils in increasingly older Precambrian strata illustrates these difficulties very clearly, and new observational and theoretical approaches are both needed and being developed. At the microscopic level of investigation, three-dimensional morphological characterization coupled with in situ chemical (isotopic, elemental, structural) analysis is the desirable first step. Geological context is paramount, as has been demonstrated by the controversies over AH84001, the Greenland graphites, and the Apex chert microfossils . At larger scales, the nature of sedimentary bedforms and the structures they display becomes crucial, and here the methods of condensed matter physics prove most useful in discriminating between biological and non-biological constructions. Ultimately, a combination of geochemical, morphological, and contextural evidence may be required for certain life detection on the early Earth or elsewhere.

Runnegar, B.↗