ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • LUNAR AND PLANETARY EXPLORATION  (723)
  • 1980-1984
  • 1975-1979  (723)
  • 1950-1954
  • 1977  (723)
Sammlung
Schlagwörter
Erscheinungszeitraum
  • 1980-1984
  • 1975-1979  (723)
  • 1950-1954
Jahr
  • 101
    facet.materialart.
    Unbekannt
    Meteorite impact ejecta - Dependence of mass and energy lost on planetary escape velocity (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The amounts of material and energy which escape a planet in a meteorite impact event is calculated as functions of impact and escape velocities. Results are obtained from the computed flow induced by the impact of iron and gabbroic anorthosite spheres onto a half-space of anorthosite at impact velocities of 5 to 45 km/sec. The impact-induced flows were determined by a numerical method using the mass, momentum, and energy conservation relations in finite-difference approximation, within an Eulerian computational grid. The impact velocities at which ejecta losses equal meteorite mass gains are found to be approximately 20, 35, and 45 km/sec for anorthosite objects and approximately 25, 35, and 40 km/sec for iron objects striking anorthosite surfaces for the gravity fields of the moon, Mercury and Mars.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 198; Dec. 23
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 102
    facet.materialart.
    Unbekannt
    Endogenic modification of impact craters on Mercury (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The presence of internally modified impact craters on Mercury's surface may be used to evaluate the possibility of Mercurian volcanism. Such craters are similar to the floor-fractured and mare-filled craters observed on the moon. Mariner-10 images show that most such craters occur, as on the moon, near plains-filled basins. Color-ratio images have indicated that some Mercurian craters manifest red plains materials on their floors. These features may be associated with lava analogous to mare basalts in some lunar craters, or with compositionally distinct subsurface material preserved within the impact crater. Several basins manifest photometric contrasts between basin exteriors and basin-filling plains. Dark haloes are observed around some impact craters superimposed on the interior plains. This suggests the excavation of compositionally distinct material. Some possible endogenic features are discerned, despite the poor surface resolution, such as irregular rimless depressions. It is felt that volcanism may have occurred on Mercury, and that in some areas it may be similar to that of the lunar Mare Australe region.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 103
    facet.materialart.
    Unbekannt
    Carbon monoxide on Jupiter and implications for atmospheric convection (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A study of the equilibrium and disequilibrium thermochemistry of the recently discovered carbon monoxide on Jupiter suggests that the presence of this gas in the visible atmosphere is a direct result of very rapid upward mixing from levels in the deep atmosphere where the temperature is about 1100 K and where carbon monoxide is thermodynamically much more stable. As a consequence the observed carbon monoxide mixing ratio is a sensitive function of the vertical eddy mixing coefficient. We infer a value for this latter coefficient which is about three to four orders of magnitude greater than that in the earth's troposphere. This result directly supports existing structural and dynamical theories implying very rapid convection in the deep Jovian atmosphere, driven by an internal heat source.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 198; Dec. 9
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 104
    facet.materialart.
    Unbekannt
    Occultation of Epsilon Geminorum by Mars. II - The structure and extinction of the Martian upper atmosphere (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The occultation of Epsilon Geminorum by Mars on April 8, 1976, was observed at three wavelengths and 4-ms time resolution with the 91-cm telescope aboard NASA's G. P. Kuiper Airborne Observatory. Temperature, pressure, and number-density profiles of the Martian atmosphere were obtained for both the immersion and emersion events. Within the altitude range 50-80 km above the mean surface, the mean temperature is about 145 K, and the profiles exhibit wavelike structures with a peak-to-peak amplitude of 35 K and a vertical scale of about 20 km. The ratio of the refractivity of the atmosphere at 4500 A and 7500 A is consistent with the atmospheric composition measured by Viking 1. From the 'central flash' - a bright feature in the light curve midway between immersion and emersion - an optical depth at 4500 A of 3.3 + or - 1.7 per km atm (about 0.23 per equivalent Martian air mass) is found for the atmosphere about 25 km above the mean surface near the south polar region. This large value and its weak wavelength dependence rule out Rayleigh scattering as the principal cause of the observed extinction.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 217
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 105
    facet.materialart.
    Unbekannt
    Al-26 in stony meteorites with gas losses (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The Al-26 content of a group of stony meteorites with low levels of He-3 (implying outgassing caused by near approach to the sun) was analyzed in a test of the possible role of cosmic radiation in determining the radionuclide concentration of meteorites. The Al-26 contents of the meteorites with He-3 losses were found to be indistinguishable from the Al-26 contents of L- and H-chondrites. It is concluded that if the He-3 outgassing occurred near the sun, the flux of particles producing Al-26 must have been nearly normal, or the diffusion process must have taken place very rapidly.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geochimica et Cosmochimica Acta; 41; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 106
    facet.materialart.
    Unbekannt
    Mg and Ca isotopic study of individual microscopic crystals from the Allende meteorite by the direct loading technique (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geochimica et Cosmochimica Acta; 41; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 107
    facet.materialart.
    Unbekannt
    Mars surface properties observed by earth-based radar at 70-, 12.5-, and 3.8-cm wavelengths (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: In the present paper, the results are summarized of a study aimed at determining the small-scale surface properties of Mars (for the Viking project) from a thorough review of all available Martian radar data for the 1973 opposition. Analysis of the quasi-specular echo component showed changes in apparent reflectivity of at least 5 to 1. If attributed entirely to variations in surface material, these correspond to dielectric constants between 1.6 and 4.0. Values of rms surface slope on 1- to 100-m scales range from as low as 0.5 degrees in tablelands near Valles Marineris to more than 3.0 degrees in certain other areas. There is a weak correlation between the small-scale surface characteristics inferred from radar and those inferred from Mariner 9 images and other remote-sensing data sets.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 108
    facet.materialart.
    Unbekannt
    Crater evolutionary tracks (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The technique proposed in the present paper for studying planetary surface processes is based on the measurement of crater rim height, h, depth, d, and diameter, D. The h/d and d/D ratios provide a quantitative description of crater morphology as well as a quantitative method for assessing the relative importance of competing crater modification processes (since h, d, and D change as a crater is degraded by surface processes, and h/d and d/D change with time). Different classes of processes produce distinctive evolutionary tracks on an h/d versus d/D diagram. Tracks for three general classes of crater modification (processes adding material to the crater; processes redistributing the material within the crater vicinity; and processes removing the material from the crater vicinity) are calculated, and h/d and d/D ratios for craters on the earth, moon, and Mars are compared.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 109
    facet.materialart.
    Unbekannt
    Application of photometric analyses for interpretation of Mars-Mariner VI and VII imagery (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The application of radiometric analysis in the interpretation of Mariner 6 and 7 imagery is investigated and illustrated. The following types of problems were felt could be addressed using this imagery: (1) evaluation of local reflectivity changes; (2) augmentation of geological mapping; (3) discrimination of atmospheric phenomena; and (4) investigation of polar cap structure.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-CR-157757 , CALSPAN-VE-3104-M-1
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 110
    facet.materialart.
    Unbekannt
    Infrared spectra of lunar soil analogs (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The infrared spectra of analogs of lunar soils were investigated to further the development of methodology for interpretation of remotely measured infrared spectra of the lunar surface. The optical constants of dunite, bytownite, augite, ilmenite, and a mare glass analog were obtained. The infrared emittance spectra of powdered minerals were measured and compared with spectra calculated by the reflectance theory using a catalog of optical constants. The results indicate that the predictions of the theory closely simulate the experimental measurements if the optical constants are properly derived.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-CR-157742
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 111
    facet.materialart.
    Unbekannt
    Viking on Mars - The carbon assimilation experiments (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A fixation of atmospheric carbon, presumably into organic form, occurs in Martian surface material under conditions approximating the actual Martian ones. The reaction showed the following characteristics. The amount of carbon fixed is small by terrestrial standards; highest yields were observed in the light, but some dark activity was also detected; and heating the surface material to 90 C for nearly 2 hours had no effect on the reaction, but heating to 175 C for 3 hours reduced it by nearly 90%. New data from Mars do not support an earlier suggestion that the reaction is inhibited by traces of water. There is evidence of considerable heterogeneity among different samples, but different aliquots from the same sample are remarkably uniform in their carbon-fixing capacity. In view of its thermostability it is unlikely that the reaction is biological.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 112
    facet.materialart.
    Unbekannt
    The Viking X ray fluorescence experiment - Sampling strategies and laboratory simulations (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Ten samples of Mars regolith material (six on Viking Lander 1 and four on Viking Lander 2) have been delivered to the X ray fluorescence spectrometers as of March 31, 1977. An additional six samples at least are planned for acquisition in the remaining Extended Mission (to January 1979) for each lander. All samples acquired are Martian fines from the near surface (less than 6-cm depth) of the landing sites except the latest on Viking Lander 1, which is fine material from the bottom of a trench dug to a depth of 25 cm. Several attempts on each lander to acquire fresh rock material (in pebble sizes) for analysis have yielded only cemented surface crustal material (duricrust). Laboratory simulation and experimentation are required both for mission planning of sampling and for interpretation of data returned from Mars. This paper is concerned with the rationale for sample site selections, surface sampler operations, and the supportive laboratory studies needed to interpret X ray results from Mars.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 113
    facet.materialart.
    Unbekannt
    The search for organic substances and inorganic volatile compounds in the surface of Mars (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A total of four Martian samples, one surface and one subsurface sample at each of the two Viking landing sites, Chryse Planitia and Utopia Planitia, have been analyzed for organic compounds by a gas chromatograph-mass spectrometer. In none of these experiments could organic material of Martian origin be detected at detection limits generally of the order of parts per billion and for a few substances closer to parts per million. The evolution of water and carbon dioxide, but not of other inorganic gases, was observed upon heating the sample to temperatures of up to 500 C. The absence of organic compounds seems to preclude their production on the planet at rates that exceed the rate of their destruction. It also makes it unlikely that living systems that behave in a manner similar to terrestrial biota exist, at least at the two Viking landing sites.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 114
    facet.materialart.
    Unbekannt
    Ultraviolet observations of Mars and Saturn by the TD1A and OAO-2 satellites (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Ultraviolet photometric and spectrophotometric observations of Mars and Saturn, obtained from two earth-orbiting satellites, are discussed. High-resolution data reveal no definite absorption features in the spectra of either planet. In order to reconcile the absence of a prominent absorption in the Mars data near 2150 A with preliminary Viking measurements of NO, this gas must be preferentially concentrated at high Martian altitudes. Broadband photometry from OAO-2 shows that atmospheric dust from the great dust storm of 1971-1972 on Mars reduced the ultraviolet geometric albedo by a factor of 3 at the height of the storm. Atmospheric energy deposition appears to be an important mechanism of the storm dynamics. The combined Saturn data indicate that NH3 is not the absorber that influences the UV spectrum of Saturn. The possibility that H2S is the absorber is investigated.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 115
    facet.materialart.
    Unbekannt
    High resolution 10 mu spectrometry at different planetary latitudes. A practical Hadamard transform spectrometer for astronomical application (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Infrared observations at different latitudes were studied in order to obtain spectra in the 10 micrometers region to understand differences in chemical composition or physical structure of the optical features. In order to receive such spectra of a rotating planet, simultaneous observations at different latitudes were made. A Hadamard transform spectrometer with 15 entrance slits was used to obtain 15 simultaneous spectra, at a resolution of 0.01 micrometers. The spectral band covered contained 255 spectral elements.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-CR-155736 , CRSR-686 , CRSR-655
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 116
    facet.materialart.
    Unbekannt
    Apollo-11 lunar sample information catalogue (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The Apollo 11 mission is reviewed with emphasis on the collection of lunar samples, their geologic setting, early processing, and preliminary examination. The experience gained during five subsequent missions was applied to obtain physical-chemical data for each sample using photographic and binocular microscope techniques. Topics discussed include: binocular examination procedure; breccia clast dexrriptuons, thin section examinations procedure typical breccia in thin section, typical basalt in thin section, sample histories, and chemical and age data. An index to photographs is included.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-TM-79344 , JSC-12522-REV
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 117
    facet.materialart.
    Unbekannt
    Viking lander camera radiometry calibration report, volume 1 (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The test methods and data reduction techniques used to determine and remove instrumental signatures from Viking Lander camera radiometry data are described. Gain, offset, and calibration constants are presented in tables.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-CR-155537 , JPL-PUB-77-62-VOL-1
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 118
    facet.materialart.
    Unbekannt
    Mercury's helium exosphere after Mariner 10's third encounter (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: From Mariner 10 third encounter UV data, a value of .00045 was calculated as the fraction of the solar wind He++ flux intercepted and captured by Mercury's magnetosphere if the observed He atmosphere is maintained by the solar wind. If an internal source for He prevails, the corresponding upper bound for the global outgassing rate is estimated to be 4.5 x 10 to the 22nd power per sec. A surface temperature distribution was used which satisfies the heat equation over Mercury's entire surface using Mariner 10 determined mean surface thermal characteristics. The means stand off distance of Mercury's magnetopause averaged over Mercury's orbit was also used.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-TM-78056 , X-621-77-269
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 119
    facet.materialart.
    Unbekannt
    Mariner 10 magnetic field observations of the Venus wake (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Magnetic field measurements made over a 21-hour interval during the Mariner 10 encounter with Venus were used to study the down-stream region of the solar wind-Venus interaction over a distance of approximately 100 R sub v. For most of the day before closest approach the spacecraft was located in a sheath-like region which was apparently bounded by planetary bow shock on the outer side and either a planetary wake boundary or transient boundary-like feature on the inner side. The spacecraft made multiple encounters with the wake-like boundary during the 21-hour interval with an increasing frequency as it approached the planet. Each pass into the wake boundary from the sheath region was consistently characterized by a slight decrease in magnetic field magnitude, a marked increase in the frequency and amplitude of field fluctuations, and a systematic clockwise rotation of the field direction when viewed from above the plane of the planet orbit.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-TM-78036 , X-695-77-206
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 120
    facet.materialart.
    Unbekannt
    An upper limit for the 34.3-MHz synchrotron flux from Uranus (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The 34.3-MHz Cocoa Cross radio telescope at Clark Lake Radio Observatory has been used to search for synchrotron radiation from Uranus between November 27, 1974, and May 13, 1975. Inspection of daily chart records for 69 observations during this time period provides a conservative upper limit to the synchrotron flux of 8 Jy. No Uranian bursts were observed. This result is compared with the kilometric burst observations of Brown (1976) as well as with models for burst and possible synchrotron emission from Uranus.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 121
    facet.materialart.
    Unbekannt
    Direct measurement of the plasma screening length and surface potential near the lunar terminator (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Direct measurement of the lunar dayside surface potential and screening length has been made by the suprathermal ion detector experiment (Side) near the terminator. In a region 20-30 deg from the terminator at the Apollo 14 and 15 sites the surface potential is found to be approximately 50 V negative, and the screening length to be about 1 km. This value of the screening length is more than 2 orders of magnitude greater than the solar wind 'Debye' length. The strong negative surface potential in this region may be due to enhanced temperature and density of the solar wind plasma.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 122
    facet.materialart.
    Unbekannt
    The 1975.9 Jovian decimetric spectrum (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The Arecibo radio telescope measured the Jovian decimetric radio flux at four frequencies - 318, 430, 1415, and 2380 - on December 5 and 6, 1975. Observed flux values were obtained by comparison with the radio sources 3C18 and 3C459. The flux values were further corrected by the beaming of the Jovian emission about the xenomagnetic equator for the antenna-emission polarization angle and for the antenna-source resolution at 1415 and 2380 MHz.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 123
    facet.materialart.
    Unbekannt
    The distribution of methylamine in the Jovian atmosphere (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: An estimate has been made of the methylamine concentration in the Jupiter atmosphere on the basis of the possible overlap between the regions of hydrocarbon and ammonia photochemistry. It was found that the maximum production rate of 6 x 10 to the 4th/cu cm/Jovian day occurs in the vicinity of 60 km above the ammonia cloud layer. The volumetric mixing ratio is 3 x 10 to the -11th, if the downward transport of methylamine equals the production rate.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters; 4; May 1977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 124
    facet.materialart.
    Unbekannt
    Model 'zero-age' lunar thermal profiles resulting from electrical induction (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Thermal profiles for the moon are calculated under the assumption that a pre-main-sequence T-Tauri-like solar wind excites both transverse magnetic and transverse electric induction while the moon is accreting. A substantial initial temperature rise occurs, possibly of sufficient magnitude to cause subsequent early extensive melting throughout the moon in conjunction with nominal long-lived radioactives. In these models, accretion is an unimportant direct source of thermal energy but is important because even small temperature rises from accretion cause significant changes in bulk electrical conductivity. Induction depends upon the radius of the moon, which we take to be accumulating while it is being heated electrically. The 'zero-age' profiles calculated in this paper are proposed as initial conditions for long-term thermal evolution of the moon.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; May 10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 125
    facet.materialart.
    Unbekannt
    Mars - Microwave detection of carbon monoxide (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The 115-gigahertz microwave line of carbon monoxide has been detected in the spectrum of Mars. The measurement is sensitive to carbon monoxide between the surface and an altitude of approximately 50 kilometers in the Martian atmosphere. This extends the altitude region to well above that previously sensed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 196; June 3
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 126
    facet.materialart.
    Unbekannt
    Topography of sinuous rilles in the Harbinger Mountains region of the moon (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Five sinuous rilles in mare basalts in the Harbinger Mountains region of the moon are described. Rille length ranges from 12 to 79 km, width from 0.8 to 4.8 km, and depth from 100 to 300 m. The rilles appear to become shallower to the north, while the southern ends are characterized by circular-to-elongate depressions that occur on a 30-km-in-diameter dome of probable volcanic origin. Longitudinal profiles show that the rille floors have a northward slope of less than one deg, consistent with the general slope of the surrounding mare surface. Structural studies indicate that slope, rather than the regional structural pattern, is the dominant factor controlling rill direction. Topographic data support the theory that the rilles were formed as lave channels or tubes.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: The Moon; 16; Mar. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 127
    facet.materialart.
    Unbekannt
    Evidence for weather on Neptune. II (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Data obtained by Joyce et al., (1977) are interpreted as evidence for the formation of an optically-thin cloud high in the atmosphere of Neptune. About 10 months after the cloud's initial appearance and subsequent partial dissipation, the optical thickness of the cloud, averaged over the planet, had a value for tau in the vicinity of 1. The minimum effective radius indicated for the cloud particles is about 1 micron. The model which leads to this interpretation of the data is explained, and the calculations are presented. Implications of the model and also apparent similarities between Neptune's atmosphere and that of other planets are discussed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 214
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 128
    facet.materialart.
    Unbekannt
    Radiometric diameters of 84 asteroids from observations in 1974-1976 (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Diameters and geometric albedos are derived from 10- and 20-micron infrared photometry for 84 asteroids, 68 of them not previously observed in this program of asteroid radiometry. All but three of the 30 brightest asteroids are included in the total sample of 131 objects, and all asteroids with diameters greater than 250 km can now be identified. The albedos are strongly bimodal, with the great majority of asteroids (class C) having visual geometric albedos between 0.025 and 0.050. The albedos of the second most numerous class, the S asteroids, are primarily between 0.10 and 0.16. The third largest class appears to be the M objects, of which seven are now identified. Apparently, the M objects are very rare for semimajor axes of less than 2.4 AU. The unusual asteroids with albedos greater than 0.20 are also discussed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 214
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 129
    facet.materialart.
    Unbekannt
    Evidence for weather on Neptune. I (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Between April 1975 and March 1976 the reflectance of Neptune between 1 and 4 microns increased substantially. A spectrum taken at these wavelengths near the period of peak observed brightness showed a low-intensity continuum with weak superposed absorptions caused by CH4 and H2. Photographic spectra of the planet measured during the same period showed no differences from older published data. The gas abundances derived from the infrared spectrum, 5 plus or minus 2 km-amagat of H2 at a base density of 0.26 plus or minus 0.08 am and no more than about 1 m-am of CH4, appear to refer to an effective reflecting level high in the atmosphere of Neptune.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 214
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 130
    facet.materialart.
    Unbekannt
    Nebular condensation of moderately volatile elements and their abundances in ordinary chondrites (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Two models accounting for the concentrations of moderately volatile elements in ordinary chondrites are discussed. The first relies on an apparent correlation between ordinary chondrite/type-I carbonaceous chondrite abundance ratios and ideal solution-condensation temperatures of such elements as Sn, Cu, Li, Na, and Mn to construct a model in which volatiles are lost as gases before nebular condensation or as finely-divided solids that are incompletely agglomerated, and the condensation/agglomeration efficiency declines as a function of time. The second theory largely discounts this gas-dust diffraction effect and instead proposed condensation on matrix and volatization from chondules and coarse metal grains as mechanisms explaining the apparent existence of three distinct classes of volatile-element abundance in ordinary chondrites.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Earth and Planetary Science Letters; 36; 1, Au; Aug. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 131
    facet.materialart.
    Unbekannt
    Crater saturation and equilibrium - A Monte Carlo simulation (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Conditions of crater saturation and equilibrium have been simulated with a Monte Carlo computer program which utilizes a generating function of the form N = b x D to the -a. The following conclusions have been deduced from the results of the model: (1) saturation and equilibrium for large craters occur at crater densities substantially greater than those observed on the moon, Mars, and Mercury, an indication that the observed populations are essentially production populations, (2) generating functions with a greater than 2 lead to final crater populations with a = 2, (3) generating functions with a between 2 and 1.5 lead to crater populations with the parameter a approaching 1.0, and (4) changes in the slope of crater populations occur gradually and over a wide interval of crater densities and diameters as saturation is approached.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; June 10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 132
    facet.materialart.
    Unbekannt
    Pontlyfni - A differentiated meteorite related to the group IAB irons (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The abundances of 23 major and trace elements in the Pontlyfni meteorite have been measured by instrumental neutron activation analysis. The compositions of the metal and silicate fractions suggest a genetic relationship between Pontlyfni and the group IAB irons.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Earth and Planetary Science Letters; 35; 1, Ma; May 1977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 133
    facet.materialart.
    Unbekannt
    A saturation model of the atmosphere of Uranus (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A model of the atmospheric structure of Uranus is presented which differs from previous types of models in two important respects: (1) the CH4/H2 ratio is sufficiently large that CH4 is saturated to large depths in the Uranian atmosphere and (2) the internal energy flux is small compared with that due to solar heating. Because of the small internal flux, the thermal flux decreases rapidly with depth and the atmosphere is radiative to large optical depths. A CH4 droplet cloud forms where the atmosphere finally becomes convective due to the internal flux. The model is shown to be in reasonable agreement with published observations of the H2 quadrupole 3-0 and 4-0 bands, the visible (4000-6000 A) CH4 bands, and the infrared emission spectrum.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 31; May 1977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 134
    facet.materialart.
    Unbekannt
    Detection of Lyman-alpha emission from the Saturnian disk and from the ring system (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A rocket-borne spectrograph detected H I Lyman-alpha emission from the disk of Saturn and from the vicinity of the planet. The signal is consistent with an emission brightness of 700 rayleighs for the disk and 200 rayleighs for the vicinity of Saturn. The emission from the vicinity of the planet may be due to a hydrogen atmosphere associated with the Saturnian ring system.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science vol. 197; Aug. 19
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 135
    facet.materialart.
    Unbekannt
    A constraint on impact theories of chondrule formation (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The association between agglutinates and chondrule-like spherules, which characterizes the assemblage of impact-derived melt products in lunar regolith samples and some gas-rich achondrites, is not found in primitive chondrites. This observation suggests that impacts into a parent-body regolith are unlikely to have produced the chondrules. We believe that if chondrules were formed from impact melt, it was probably generated by jetting during particle-to-particle collisions, presumably in the nebula.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Earth and Planetary Science Letters; 35; 1, Ma; May 1977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 136
    facet.materialart.
    Unbekannt
    Apollo 17 KREEPy basalt - A rock type intermediate between mare and KREEP basalts (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The Apollo 17 KREEPy basalt is a unique lunar volcanic rock, observed only as clasts in the light friable breccia matrix (72275) of Boulder 1, Station 2 at Taurus-Littrow. Its status as a volcanic rock is confirmed by the absence of any meteoritic contamination, a lack of cognate inclusions or xenocrystal material, and low Ni contents in metal grains. The basalt was extruded 4.01 + or - 0.04 b.y. ago, approximately contemporaneously with the high-alumina mare basalts at Fra Mauro; shortly afterwards it was disrupted, probably by the Serenitatis impact, and its fragments emplaced in the South Massif. The basalt, which is quartz-normative and aluminous, is chemically and mineralogically intermediate between the Apollo 15 KREEP basalts and the high-alumina mare basalts in most respects. It consists mainly of plagioclase and pigeonitic pyroxene in approximately equal amounts, and 10-30% of mesostatis.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Earth and Planetary Science Letters; 35; 1, Ma; May 1977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 137
    facet.materialart.
    Unbekannt
    Iron - Whence it came, where it went (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Determinations of the abundances of iron and related elements in the photosphere, chromosphere, and corona of the sun as well as in solar and galactic cosmic rays are reviewed and compared with abundances derived from meteoritic data. Observed solar system abundances are found to be in accord with predictions of nucleosynthesis under either hydrostatic or explosive conditions but cannot yet be used to define these processes uniquely. The distribution of iron among planets and meteorites can probably be adequately modelled by condensation and fragmentation under equilibrium conditions above about 700 K, but below that temperature it is likely that inhibited solid-state diffusion perturbed attainment of equilibrium. Pertinent factors which are presently unknown include the mechanism responsible for metal-silicate fractionation, the grain size achieved by metallic iron in the nebula, and whether iron-bearing silicate formed prior to accretion.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Space Science Reviews; 20; Feb. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 138
    facet.materialart.
    Unbekannt
    Planimetric Martian triangulations (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Narrow-angle photographs, which have severe drawbacks for stereophotogrammetry, have advantages for simple plane triangulations. Rectified narrow-angle pictures corrected for map projection effects can be combined in the map plane in relatively accurate planimetric triangulations. Provided the strict precepts of least squares are not followed, these triangulations can incorporate considerable overdetermination without increase in the labor of solving the equations. These plane triangulations have been used successfully in the cartography of Mars and are illustrated here by a triangulation of the environs of the prime Martian landing site.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Photogrammetric Engineering and Remote Sensing; 43; June 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 139
    facet.materialart.
    Unbekannt
    The tilt effect for Saturn's rings (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Multiple-scattering computations are carried out to explain the variation of the observed brightness of the A and B rings of Saturn with declination of the earth and sun. These computations are performed by a doubling scheme for a homogeneous plane-parallel scattering medium. A range of choices is tested for the phase function, albedo for single scattering, and optical depth of both the rings. Isotropic scattering and several other simple phase functions are ruled out, and it is found that the phase function must be moderately peaked in both the forward and backward directions. The tilt effect can be explained by multiple scattering in a homogeneous layer, but, for ring B, this requires a single-scattering albedo in excess of 0.8. The brightest part of ring B must have an optical depth greater than 0.9. It is found that the tilt effect for ring A can be reproduced by particles having the same properties as those in ring B with the optical depth for the A ring in the range 0.4 to 0.6.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 31; May 1977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 140
    facet.materialart.
    Unbekannt
    Spectral reflectance of Martian areas during the 1973 opposition - Photoelectric filter photometry 0.33-1.10 microns (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 31; May 1977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 141
    facet.materialart.
    Unbekannt
    Observations of the 13th satellite of Jupiter during the 1975-1976 opposition (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Observations of the 13th satellite of Jupiter during the 1976-1976 opposition
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 142
    facet.materialart.
    Unbekannt
    Io - Morphology of its sodium emission region (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Results of experiments carried out to obtain two-dimensional images of the sodium emission region associated with Io are presented. Through multislit spectrograms and Perot-Fabry interferograms, the dependence of the Na-emission distribution on Jupiter's magnetic field is demonstrated. The time scale of the observed changes in the Na emission is shown to require electron fluxes in the Jovian magnetosphere one order of magnitude larger than those obtained by an extrapolation of the proton fluxes measured in situ from the Pioneer 10 spacecraft.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astronomical Society of the Pacific; vol. 89
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 143
    facet.materialart.
    Unbekannt
    Surface of Venus - Evidence of diverse landforms from radar observations (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Radar images seem to indicate that some regions of Venus have remained little altered since a period of intense bombardment similar to that recorded by the many large impact craters on the moon. On the other hand, there is evidence in other regions that Venus has been a geologically active planet, forming diverse landforms, and perhaps rivaling the earth in the breadth of features portrayed on its surface
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 196; May 27
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 144
    facet.materialart.
    Unbekannt
    Moonquakes - Mechanisms and relation to tidal stresses (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Observed features of moonquakes are combined with theoretical calculations of the tidal stresses to interpret the moonquake mechanisms. Tidal stresses, together with a postulated ambient tectonic stress, are sufficient to explain the depth, periodicity, and polarity reversal of moonquakes. Both of these stresses are small (on the order of 1 bar) and consistent with the small magnitudes of moonquakes.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 196; May 27
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 145
    facet.materialart.
    Unbekannt
    The Viking X ray fluorescence experiment - Analytical methods and early results (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Ten samples of the Martian regolith have been analyzed by the Viking lander X ray fluorescence spectrometers. Because of high-stability electronics, inclusion of calibration targets, and special data encoding within the instruments the quality of the analyses performed on Mars is closely equivalent to that attainable with the same instruments operated in the laboratory. Determination of absolute elemental concentrations requires gain drift adjustments, subtraction of background components, and use of a mathematical response model with adjustable parameters set by prelaunch measurements on selected rock standards. Bulk fines at both Viking landing sites are quite similar in composition, implying that a chemically and mineralogically homogeneous regolith covers much of the surface of the planet. Important differences between samples include a higher sulfur content in what appear to be duricrust fragments than in fines and a lower iron content in fines taken from beneath large rocks than those taken from unprotected surface material. Further extensive reduction of these data will allow more precise and more accurate analytical numbers to be determined and thus a more comprehensive understanding of elemental trends between samples.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 146
    facet.materialart.
    Unbekannt
    Surface materials of the Viking landing sites (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: In the present paper, the soil characteristics at the Viking sites are discussed in terms of bulk density, particle size, angle of internal friction, cohesion, and moisture content. At the Viking Lander-1 site, there is a relatively weak drift material, along with more cohesive materials of a rocky area, and rocks. A variety of materials are present also at the Lander-2 site. Moisture content is low as compared to terrestrial soils. Current estimates of some of the physical properties are tabulated and discussed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 147
    facet.materialart.
    Unbekannt
    Seismology on Mars (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: High-quality data (uncontaminated by lander or wind noise) obtained with a three-axis short-period seismometer operating on Mars in the Utopia Planitia region are analyzed. No large events have been detected during the first five months of operation covered in the present paper. This indicates that Mars is less seismically active than the earth. Winds, and therefore a seismic background, began to intrude into the nighttime hours, starting with sol 119 (sol is a Martian day). The seismic background correlates well with wind velocity, and is proportional to the square of the wind velocity, as is appropriate for turbulent flow. A local seismic event of a magnitude of 3 and a distance of 110 km was detected on sol 80. It is interpreted as a natural seismic event.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 148
    facet.materialart.
    Unbekannt
    The rotation of Uranus (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The rotation rate of Uranus is investigated by measuring the tilts of reflected Fraunhofer lines observed through a slit spectrograph. The data obtained are corrected for the effect of astronomical seeing, and the data-reduction procedures are outlined in detail. Observations are discussed which indicate that the planet's pole of rotation is parallel to the pole of its satellites' orbits and that Uranus may not rotate as a solid body. A rotational period of 15.57 + or - 0.80 hr is derived for northern midlatitudes on Uranus by adopting a planetary diameter of 51,800 + or - 600 km. Possible sources of small systematic errors are briefly considered.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 217
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 149
    facet.materialart.
    Unbekannt
    Asteroid surface materials: Mineralogical characterizations from reflectance spectra (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Mineral assemblages analogous to most meteorite types, with the exception of ordinary chondritic assemblages, have been found as surface materials of Main Belt asteroids. C1- and C2-like assemblages (unleached, oxidized meteoritic clay minerals plus opaques such as carbon) dominate the population throughout the Belt, especially in the outer Belt. A smaller population of asteroids exhibit surface materials similar to C3 (CO, CV) meteoritic assemblages (olivine plus opaque, probably carbon) and are also distributed throughout the Belt. The majority of remaining studied asteroids (20) of 65 asteroids exhibit spectral reflectance curves dominated by the presence of metallic nickel-iron in their surface materials. The C2-like materials which dominate the main asteroid belt population appear to be relatively rare on earth-approaching asteroids.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-CR-154510 , PUBL-151
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 150
    facet.materialart.
    Unbekannt
    Detection of methane and ethane emission on Neptune but not on Uranus (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 218
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 151
    facet.materialart.
    Unbekannt
    Search for Jovian auroral hot spots (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Auroral emission originating at the foot of the Io-associated flux tube at Jupiter has been detected with a high-resolution spectrometer/telescope on board the Orbiting Astronomical Observatory Copernicus. The emission intensity at Ly-alpha is found to be greater than 100 kR, and the emission is located at zenographic latitudes greater than 65 deg.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 218
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 152
    facet.materialart.
    Unbekannt
    Ionosphere and atmosphere of the moon in the geomagnetic tail (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The paper presents calculations of the densities and energies of the various constituents of the lunar ionosphere during the time that the moon is in the geomagnetic tail; the surface concentrations of neon and argon are calculated from a theoretical model to be 3,900 and 1,700, respectively. It is found that a hydrostatic model of the ionospheric plasma is inadequate because the gravitational potential energy of the plasma is considerably smaller than its thermal energy. A hydrodynamic model, comparable to that used to describe the solar wind, is developed to obtain plasma densities and flow velocities as functions of altitude. The electromagnetic properties of the quiescent ionosphere are then investigated, and it is concluded that plasma effects on lunar induction can be neglected for quiescent conditions in the geomagnetic tail lobes.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Nov. 10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 153
    facet.materialart.
    Unbekannt
    The abundance of acetylene in the atmosphere of Jupiter (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The Q and R branches of the C2H2 nu(5) fundamental, observed in emission in an aircraft spectrum of Jupiter near 750/cm, have been analyzed with the help of an improved line listing for this band. The line parameters have been certified in the laboratory with the same interferometer used in the Jovian observations. The maximum mixing ratio of C2H2 is found to be between 5 times 10 to the -8th and 6 times 10 to the -9th power, depending on the form of its vertical distribution and the temperature structure assumed for the lower stratosphere. Most consistent with observations of both Q and R branches are: (1) distributions of C2H2 with a constant mixing ratio in the stratosphere and a cutoff at a total pressure of 100 mbar or less, and (2) the assumption of a temperature at 0.01 bar which is near 155 K.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Dec. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 154
    facet.materialart.
    Unbekannt
    Uranus' rotational period (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A modified spectroscopic technique was applied to determine the rotational period of Uranus and the orientation of the projected spin axis of the planet. The method consists in obtaining a series of spectra for both a nonrotated planet disk and for a disk rotated 180 degrees. Ignoring the effects of seeing in analyzing the spectra for no rotation of the disk leads to a lower limit on the period, and for a disk rotated 180 degrees, ignoring the seeing in the modeling of the spectra leads to an upper limit on the period. When blurring from seeing and guiding errors are added to the modeling for both image orientations and the model spectra are compared to the observations, both the period and the degree of blurring are obtained simultaneously. The results gave a period of rotation of Uranus 23 + 5 or - 2 hr.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Dec. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 155
    facet.materialart.
    Unbekannt
    Trace elements in the Allende meteorite. III - Coarse-grained inclusions revisited (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Radiochemical neutron activation analytic determinations of several elements in coarse-grained inclusions of the Allende meteorite are reported. The condensation and fractionation behavior of these and other elements are described. Evidence was found for a post-accretion thermal event which redistributed some trace elements. The solar system ratio of Zr/Hf is computed on the basis of the minimum variation in the inclusion, and the percentage of high-temperature condensates in the earth and moon are calculated on the basis of the mean U content of the inclusions. The mean value of the enrichment factors of 21 refractory elements relative to C1 chondrites is provided, and the elements that did or did not condense in a solid solution of melilite are listed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geochimica et Cosmochimica Acta; 41; Nov. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 156
    facet.materialart.
    Unbekannt
    An improved lunar moment of inertia determination - A proposed strategy (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A strategy for determining an improved lunar moment of inertia is proposed. An improved uncertainty in the lunar inhomogeneity parameter could reduce the core density error from 4.20 gr/cu cm to 0.1 gm/cu cm for the case of a lunar density model having a 300 km core radius. The current error of 0.0025 for the lunar inhomogeneity parameter is mostly due to the uncertainties in the C20 and C22 gravity harmonics. An optimum reduction strategy for obtaining an order of magnitude improvement in the gravity estimates is based on covariance analyses of Doppler data. The long-arc reduction method is shown to provide better results than the short-arc technique, and the use of an orbit with a 7000 km semimajor axis along with certain terms of up to degree and order eight is recommended.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: The Moon; 17; Sept
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 157
    facet.materialart.
    Unbekannt
    Luna 24 - Opaque mineral chemistry of gabbroic and basaltic fragments from Mare Crisium (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Spinels and ilmenites are relatively sparse in the Luna 24 gabbro and basalts. Spinel compositions show some affinities to those of spinels in Apollo 12, Apollo 14 and Luna 16 basalts; a characteristic feature is high Al2O3, reaching a maximum of 19.8 wt%. A comparison of spinels in the Luna 24 gabbro with those in other deep-seated lunar intrusive rocks shows a characteristic trend for Fe/Mg. This trend is systematic from gabbro to anorthosite to troctolite and is interpreted to be P-T dependent. Compositions of spinels in the gabbro fall within the Cr/Al trend defined by the spinels of the basalts, but form a Fe/Mg trend parallel to that of the basalts; this relationship suggests that both the gabbro and the basalts are derived from a closely similar source region, with the basalts originating at a slightly greater depth than the gabbro. The spinels in both rock types are considered to have formed at high crustal levels, at low pressures. The Luna 24 data suggest that the compositional discontinuities which exist between chromian spinels and titanian spinels in a large proportion of mare basalts are the result of nucleation of chromian spinels at high crustal levels prior to eruption, and of titanian spinels during melt crystallization at the lunar surface.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters; 4; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 158
    facet.materialart.
    Unbekannt
    High-silica glass inclusions in olivine of Luna-24 samples (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Optical examination of nine polished grain mounts of Luna-24 drill-core material (0.09-0.50 mm size) revealed melt inclusions in olivine crystals. Two inclusions consist of clear glass with exceptionally high Si, yet contain no visible daughter minerals and have had no reaction effects with the olivine walls. Their compositions (one has SiO2 93.8, Al2O3 1.51, FeO 2.32, MgO 1.61, CaO 0.06, Na2O less than 0.05, K2O 0.11, total 99.41%; the other is similar) are unique and quite unlike the high-Si high-K melt of granitic composition that is found as inclusions in late-stage minerals of these (and the Apollo) samples, from silicate liquid immiscibility. The host olivines are Fo73 and Fo51. The origin of the melt in the inclusions and the lack of reaction effects are perplexing unsolved problems.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters; 4; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 159
    facet.materialart.
    Unbekannt
    Laboratory simulation of the lunar magnetosphere (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The magnetic field disturbance created by the impingement of a supermagnetosonic collision-free plasma upon a hollow, electrically nonconducting body (lunella) has been studied in the laboratory using a plasma accelerator. Diamagnetic currents on the boundary of the downstream cavity which is formed are the source of these disturbances which fringe out within the lunella and extend on into the upstream flow to a distance of about the geometric mean Larmor radius. Additional field perturbations and associated currents appear over the upstream hemisphere. The results are in qualitative accord with lunar magnetometer data and bear upon the interaction of the solar wind with small non-magnetic bodies.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters; 4; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 160
    facet.materialart.
    Unbekannt
    Quantitative analysis of the Dermott-Gold theory for Uranus's rings (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A summary is presented of an investigation which supplements the largely qualitative analysis conducted by Dermott and Gold (1977). Dermott and Gold have attempted to explain the locations of Uranus's rings in terms of resonances between ring particles and pairs of satellites. An equation of motion, analogous to that of a pendulum, is derived, taking into account a study by Wilkens (1933) of possible three-body resonances involving one minor and two major planets. Dermott and Gold had concluded that the observed pattern is probably due primarily to the effect of Ariel-Titania and Ariel-Oberon pairs. However, on the basis of the values derived in the reported investigation it is seen that Miranda plays the key role rather than Ariel, in spite of the small mass of the former. It is concluded that a decisive test of the Dermott-Gold theory has to await further observational details concerning the Uranus's rings.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Nature; 269; Oct. 27
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 161
    facet.materialart.
    Unbekannt
    The dynamics and helium distribution in hydrogen-helium fluid planets (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The simple case of a homogeneous planet without first-order phase transitions is considered and an investigation is conducted concerning a pure hydrogen planet in which a first-order phase transition takes place from fluid molecular hydrogen to fluid metallic hydrogen. Attention is also given to convection in the presence of a compositional gradient, the effects of helium insolubility in a cooling hydrogen-helium planet, a hydrogen-helium planet in its early evolution, and the case in which influence of phase transition occurs much later in the evolution of the planet.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal Supplement Series; 35; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 162
    facet.materialart.
    Unbekannt
    The phase diagram and transport properties for hydrogen-helium fluid planets (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The properties of pure hydrogen and helium are examined, taking into account metallic hydrogen, molecular hydrogen, and the molecular-metallic transition. Metallic hydrogen-helium mixtures are considered along with molecular hydrogen-helium mixtures, the total phase diagram, and minor constituents, including deuterium. The transport properties of the metallic and the molecular phase are also discussed, giving attention to electrical conductivity, thermal conductivity, viscosity, self-diffusion, interdiffusion, radiative opacity, and second-order transport coefficients.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal Supplement Series; 35; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 163
    facet.materialart.
    Unbekannt
    Mars and earth - Origin and abundance of volatiles (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: An investigation is conducted concerning the factors which are responsible for the tenuous nature of the Martian atmosphere in comparison to the terrestrial atmosphere, taking into account new data obtained in connection with the Viking missions. It is found that Mars was poor in volatiles from the start and fell further behind earth by less complete outgassing, by extensive retrapping, and by the partial loss of lighter gases. Attention is given to noble gases on earth and Mars, the condensation of noble gases and other volatiles, the sources of earth's volatiles, the bulk composition of earth, the release of volatiles from earth, clues to the volatile endowment of Mars, an abundance table for Mars, a comparison of terrestrial and Martian conditions, isotopic data on noble gases, xenon-129 on Mars and earth, possibilities concerning the loss of an early Martian atmosphere, the evolution of the atmosphere of Mars, conditions in the case of planet Venus, and the reasons for the poorness of small planets in volatiles.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 198; Nov. 4
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 164
    facet.materialart.
    Unbekannt
    On the prograde rotation of asteroids (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Sets of diameter determinations before and after opposition for the asteroids Ceres, Pallas, Vesta, and Fortuna have been studied statistically for indications of spin direction. All four asteroids are tentatively found to have prograde spin. For Ceres, that conclusion is virtually certain.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Dec. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 165
    facet.materialart.
    Unbekannt
    Far-infrared spectral observations of Saturn and its rings (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The spectrum of Saturn and its rings between 45 and 115 microns has been measured at an average resolving power of 14 from the NASA Lear Jet. The combined brightness temperature of the rings and planetary disk decreases beyond 65 microns, in disagreement with previous results. A brightness temperature of 65 + or - 10 K is obtained for the planetary disk in the 80-110-micron wavelength range if a large-particle, constant-emissivity model is assumed for the rings. The possible effects of small particles in the rings are briefly considered.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Dec. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 166
    facet.materialart.
    Unbekannt
    The effective temperature of Neptune (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The brightness temperature of Neptune has been measured in two broad passbands with flux-weighted mean wavelengths of 45 and 93 microns, permitting a direct determination of its effective temperature. The derived value of 55.5 plus or minus 2.3 K implies that Neptune radiates twice as much power as it receives from the sun.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 218
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 167
    facet.materialart.
    Unbekannt
    Why is a minor planet minor (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A hypothesis based on the accretion model of planet formation is proposed which can explain why minor planets could not grow into full-sized planets. Temperature and impact-velocity conditions for bouncing, accumulation, and fragmentation of planetesimals are evaluated for silicate and iron planetesimals at the heliocentric distances of Mercury, Venus, earth, Mars, and the asteroid belt. The results indicate that the low-temperature environment of the asteroids very likely hampered their growth into ironlike planetesimals, which in turn inhibited the accumulation of silicate planetesimals. It is concluded that the brittleness of iron at temperatures below 200 to 250 K is the primary reason why minor planets are 'minor' and could not grow to full size.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Nature; 270; Dec. 8
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 168
    facet.materialart.
    Unbekannt
    Moon-Mercury - Relative preservation states of secondary craters (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Geologic studies including mapping of the Kuiper quadrangle of Mercury suggest that secondary craters are much better preserved than those on the moon. Factors which may account for the apparent differences between lunar and Mercurian secondary crater morphology include: (1) the rapid isostatic adjustment of the parent crater, (2) different impact fluxes of the two planets, (3) the greater concentration of Mercurian secondaries around impact areas, and (4) differences in crater ejection velocities. It has been shown that the ejection velocities on Mercury are about 50% greater than those on the moon at equivalent ranges. This may account for morphologically enhanced secondary craters, and may explain their better preservation with time.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 169
    facet.materialart.
    Unbekannt
    Rayed craters on the moon and Mercury (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Systems of bright rays are exhibited by many fresh craters on the moon and Mercury. Diameter/density distributions suggest that lunar-rayed craters represent the Class 1 craters, and that Mercurian rayed craters represent post-Caloris craters. Photogeological analyses of lunar imagery indicate that the ray systems are composed of finely divided material from the primary crater along with locally derived ejecta from secondary and tertiary craters. The primary ray material probably occurs in moderately thick (0.1-1 meter) deposits. The rate of darkening may depend more on the thickness of the ray material than on the rates of various darkening processes. Darkening rate may also be a function of crater size. It is observed that rays of craters more than 1 b.y. old remain bright, whereas those older than Class 1 generally fade to imperceptibility.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 170
    facet.materialart.
    Unbekannt
    The relationship between crustal tectonics and internal evolution in the moon and Mercury (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The relationship between crustal tectonics and thermal evolution is discussed in terms of the moon and Mercury. Finite strain theory and depth and temperature-dependent thermal expansion are used to evaluate previous conclusions about early lunar history. Factors bringing about core differentiation in the first 0.6 b.y. of Mercurian evolution are described. The influence of concentrating radioactive heat sources located in Mercury's crust on the predicted contraction is outlined. The predicted planetary volume change is explored with regard to quantitative limits on the extent of Mercurian core solidification. Lunar and Mercurian thermal stresses involved in thermal evolution are reviewed, noting the history of surface volcanism. It is concluded that surface faulting and volcanism are closely associated with the thermal evolution of the whole planetary volume. As the planet cools or is heated, several types of tectonic and volcanic effects may be produced by thermal stress occurring in the lithosphere.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 171
    facet.materialart.
    Unbekannt
    Recent results from the Viking Labeled Release experiment on Mars (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The Labeled Release (LR) life detection experiment seeks detection of heterotrophic metabolism by monitoring radio-active gas evolution following the addition of a radioactive nutrient containing seven C-14 labeled organic substrates to surface material. LR results obtained on Mars prior to conjunction showed rapid evolution of radioactive counts upon addition of the nutrient to a fresh surface sample. The responses at both landing sites were quite similar. The additional results summarized in the present paper provide further information on the gas kinetics following a second injection of nutrient and on the effect of 'cold sterilization' of the Martian surface material. Specifically, it is shown that the production of gas from the LR nutrient is remarkably uniform; after reaction approaches completion, addition of more nutrient results in a net loss of the radioactive gas; the reactant in the Mars soil is completely inhibited by heating the soil to 160 C, and is largely inhibited by heating to 46 C. In contrast, exposure to 18 C for 2 sol (1 sol = 24.6 hr) does not appear to inhibit the reaction.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 172
    facet.materialart.
    Unbekannt
    The composition of the atmosphere at the surface of Mars (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The current status is summarized of investigations of the composition of the Martian atmosphere, in which use was made of the mass spectrometers that function as the analytical component of the molecular analysis experiments on the two Viking landers. The following points seem well established: N2, Ar-40, Ne, Kr, Xe, and the primordial isotope of Ar are present. The present atmosphere of Mars represents only a small fraction of the total amount of volatiles outgassed by the planet, so that high surface pressure and abundant water may have been present. The noble gases in the Martian atmosphere exhibit a relative abundance pattern similar to that in the earth's atmosphere and (except for Xe) to that in the primordial component of meteorites. The existence of a 'planetary component' is thus proven, supporting the arguments of those who favor a fractionation of noble gases prior to the formation of the planets. In spite of these similarities, the isotopic ratios of nitrogen, argon, and xenon indicate that the histories of the Martian and the earth's atmospheres have been very different.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 173
    facet.materialart.
    Unbekannt
    Geochemical and mineralogical interpretation of the Viking inorganic chemical results (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The current status of geochemical, mineralogical, petrological interpretation of refined Viking Lander data is reviewed, and inferences that can be drawn from data on the composition of Martian surface materials are presented. The materials are dominantly fine silicate particles admixed with, or including, iron oxide particles. Both major element and trace element abundances in all samples are indicative of mafic source rocks (rather than more highly differentiated salic materials). The surface fines are nearly identical in composition at the two widely separated Lander sites, except for some lithologic diversity at the 100-m scale. This implies that some agency (presumably aeolian processes) has thoroughly homogenized them on a planetary scale. The most plausible model for the mineralogical constitution of the fine-grained surface materials at the two Lander sites is a fine-grained mixture dominated by iron-rich smectites, or their degradation products, with ferric oxides, probably including maghemite and carbonates (such as calcite), but not such less stable phases as magnesite or siderite.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 174
    facet.materialart.
    Unbekannt
    Meteorological results from the surface of Mars - Viking 1 and 2 (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The meteorology equipment carried by the Viking landers was intended to measure atmospheric temperature, wind speed, wind direction, and pressure. During the summer months, the winds were a few meters per second, with a complex hodograph and the Lander-1 site, dominated by counterclockwise turning of the wind, and a simpler hodograph at the Lander-2 site, marked by clockwise turning of the wind. With advancing season, the repetitive wind pattern began to break down, and protracted northeasterly winds were recorded on several occasions (some of which are associated with lower than normal temperatures). Examples are given of wind and temperature traces over short periods, illustrating the effects of convection, static stability, and lander interference. A theoretical argument, based on the horizontal scale dictated by heating of slopes and on vertical mixing of momentum, is presented to explain the different sense of wind rotation at the two lander sites.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 175
    facet.materialart.
    Unbekannt
    The Viking magnetic properties experiment - Primary mission results (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Three permanent magnet arrays were mounted on each Viking lander: a strong array fixed on a photometric reference test chart on top of the landers; and two arrays, one strong and one weak, incorporated into the backhoe of the surface sampler. Some or all of the magnetic particles detected could be highly magnetic unoxidized mineral grains (metallic Fe, magnetite, pyrrhotite) forming the core beneath a reddish coating of limonite or hematite; or grains composed of gamma-Fe2O3, with and without other iron oxides; or igneous rock (or mineral particles) which consist of an admixture of unweathered silicate material or minerals with a significant fraction of highly magnetic phase, again with a reddish coating; they could be also igneous rock or mineral particles, intrinsically nonmagnetic, but having a reddish coating containing gamma-Fe2O3; or clay mineral particles which contain and/or are coated with Fe2O3, of which a substantial fraction is in the gamma-Fe2O3 form.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 176
    facet.materialart.
    Unbekannt
    Properties of aerosols in the Martian atmosphere, as inferred from Viking Lander imaging data (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Three types of aerosol were detected from observations of the Martian sky, Phobos, and the sun with the Viking imaging cameras. Atmospheric optical depths were derived from observations of the objects' brightness. Data on the absorption coefficient, mean size, and shape of aerosols were obtained from studies of the sky brightness, using a multiple-scattering computer code. The aerosol types were water ice ground fog, a higher-level ice cloud (polar hood), and soil particles suspended at heights up to 30 km. The properties of each type of aerosol are discussed. The data are subjected to thorough analysis, and the results are summarized.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 177
    facet.materialart.
    Unbekannt
    The geology of the Viking Lander 2 site (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Models are discussed of several competitive geologic histories that can be hypothesized for the Viking Lander 2 site, none of which is uniquely persuasive. The craft landed on a flat plain of fine-grained sediment overlain by dispersed evenly distributed boulders. The fine-grain material appears to be part of a high-latitude mantle comprising material swept south of the pole regions. The boulders, which are covered by distinctive deep pits, or vesicles, may be the residue of an ejecta deposit from the crater Mie. Alternatively, they may be the remnants of lava flows which formerly covered the region. Polygonal sediment-filled cracks may have been formed by ice wedging, similar to the process that occurs in terrestrial permafrost regions. The possibility that they are desiccation polygons may not be excluded.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 178
    facet.materialart.
    Unbekannt
    The geology of the Viking Lander 1 site (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Stereo pictures show that Viking Lander 1 landed on volcanic terrain of undulating topography in the plains of Chryse. The bedrock is exposed along several ridge crests, and blocks are more numerous than can be attributed to impact ejecta. The presence of a variety of rock types suggests in situ weathering of extrusive and near-surface basaltic igneous rocks along a linear volcanic vent. Fine-grained sediment is present in drift complexes and isolated drifts. A small patch of fine-grained sediment slumped down one of the drift faces during the course of the Viking mission. Otherwise, no other morphological changes unrelated to spacecraft activity have been observed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 179
    facet.materialart.
    Unbekannt
    Particle motion on Mars inferred from the Viking lander cameras (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Data from Viking lander cameras indicate fine particle mobility on the surface of Mars such as: probable ventifacts, rock-associated raised streaks, and particulate drifts. Peak wind directions inferred from Chryse and Utopia are roughly equal, and are consistant with those inferred by orbiter photography. A 24 deg systematic offset between: (1) the direction of rock-associated streaks in the Viking I landing site, and (2) Mariner 9 and Viking observations of crater-associated streaks is consistant with a Coriolis acceleration of particles entrained by high-velocity winds during the production of crater-associated streaks. It is suggested that if a large fraction of collision impact energy goes into deformation, strain, and rupture, a preferential destruction of the most easily saltated grains and a depletion of 15-micron diameter grains will be observed. Investigations of particulates dumped on the landing grid suggest that major saltation events took place between sols 96 and 207, caused by winds of greater than 50 meters/sec normalized to the top of the boundary layer.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 180
    facet.materialart.
    Unbekannt
    Photochemistry and evolution of Mars' atmosphere - A Viking perspective (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Viking measurements of the upper atmosphere of Mars have indicated thermospheric temperatures below 200 K, colder than those originally calculated by remote sensing experiments. It is suggested that dynamical coupling of the upper and lower regions of the Martian atmosphere may account for the variability in thermospheric temperature. The absorption of extreme ultraviolet solar radiation may account for observed ionospheric features, and may provide a source of fast N and O atoms escaping the planet's gravitational field. Measurements of the isotopic composition of O and N may be used to place constraints on models of the evolution of the Martian atmosphere. It is suggested that previous abundance of N2 may have exceeded that of CO2 in the present atmosphere, and that large sources of H2O may exist on the planet. The present degassing rate for nitrogen is felt to be less than the time-averaged degassing rate by at least a factor of 20.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 181
    facet.materialart.
    Unbekannt
    The Martian ionosphere as observed by the Viking retarding potential analyzers (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The first in situ measurements of the ionosphere of another planet were obtained by retarding potential analyzers of the Viking landers. These results are presented with attention to: (1) the determination of the peak ion concentration in the ionosphere layer at several altitudes, (2) the measurement of ion temperatures, and (3) an equatorward horizontal ion velocity observed at various heights. Both landers entered the ionosphere layer at solar zenith angles near 44 deg, and more structure was observed in the height profiles of ionospheric quantities on Viking 2, although the profiles were similar in shape to those of Viking 1.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; Sept. 30
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 182
    facet.materialart.
    Unbekannt
    Chemical and petrographic constraints on the origin of chondrules and inclusions in carbonaceous chondrites (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Bulk chemical compositions of the various petrographic types of chondrules and inclusions in Type 3 carbonaceous chondrites (excluding those affected by metamorphism) have been determined by microprobe defocused-beam analysis. Inclusion compositions follow approximately the theoretical compositional trajectory for equlibrium condensation. Chondrules occurring in the same meteorites have higher silica contents and show only slight overlap with inclusion compositions. Dust fusion is apparently an inadequate mechanism for producing the wide chemical variations observed among chondrules. Impact-melting models require sampling of complex target rocks which are unknown as components of meteorites; this mechanism also demands efficient mechanical processing of chondrules before accretion. A genetic relationship between chondrules and inclusions in carbonaceous chondrites is suggested by the compositional continuum between these objects. A condensation sequence which dips into the liquid stability field at lower temperatures is advocated for the production of both inclusions and chondrules. Textural relationships between intergrown chondrules and inclusions support such a sequence. This model suggests that the assembled components (inclusions and chondrules) of carbonaceous chondrites are related by a common process.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geochimica et Cosmochimica Acta; 41; Dec. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 183
    facet.materialart.
    Unbekannt
    Petrographic variations among carbonaceous chondrites of the Vigarano type (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The Vigarano subtype is a petrographically complex class of meteorites. Oxidized and reduced groups can be distinguished on the basis of metal vs magnetite abundances and Ni contents of sulfide minerals. These meteorites also differ in the proportions of matrix and chondrules and in polymict character. Slight bulk chemical differences correlate with the recognized petrologic groupings. It is likely that the Vigarano subtype includes several previously unrecognized subgroups. Metamorphism has affected Coolidge, Mulga (West) and, to a lesser extent, Allende, as evidenced by ferromagnesian mineral equilibration, Fe-enrichment of fine-grained inclusions, and loss of some volatile gases. Because of the metamorphic effects in the Allende chondrite (the only meteorite of the group that has been intensively studied) and the petrographic differences among all meteorites of the Vigarano subtype, it is suggested that Allende alone may not adequately reflect the wide spectrum of properties in this important class of meteorites.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geochimica et Cosmochimica Acta; 41; Dec. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 184
    facet.materialart.
    Unbekannt
    Primordial noble gases in chondrites - The abundance pattern was established in the solar nebula (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Ordinary chondrites, like carbonaceous chondrites, contain primordial noble gases mainly in a minor phase comprising not more than 0.05 percent of the meteorite, probably an iron-chromium sulfide. The neon-20/argon-36 ratios decrease with increasing argon-36 concentration, as expected if the gas pattern was established by condensation from the solar nebula, and was negligibly altered by metamorphism in the meteorite parent bodies. Meteoritic and planetary matter apparently condensed over a substantial range of temperatures.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 198; Dec. 2
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 185
    facet.materialart.
    Unbekannt
    Geologic interpretation of new observations of the surface of Venus (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: New radar observations of the surface of Venus provide further evidence of a diverse and complex geologic evolution. The radar bright feature 'Beta' (24 deg N, 85 deg W) is seen to be a 700 km diameter region elevated a maximum of approximately 10 km relative to its surroundings with a 60 x 90 km wide depression at its summit. 'Beta' is interpreted to be a large volcanic construct, analogous to terrestrial and Martian shield volcanoes. Two large, quasi-circular areas of low reflectivity, examples of a class of features interpreted to be impact basins by previous investigators who were without the benefit of actual topographic information, are shown in altimetry maps to be depressions. Thus the term 'basin' can be applied, although we urge a non-genetic usage until more complete understanding of their origin is achieved through analysis of future observations.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters; 4; Nov. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 186
    facet.materialart.
    Unbekannt
    Search for correlation between asteroid families and classes (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A correlation between membership in a dynamically defined asteroid family and membership in a given asteroid spectral class is sought. Examination of 10 families each with five or more classified members indicates a correlation for the 4 families whose existence is best established, and no correlation for the remaining 6 families. This conclusion supports the break-up hypothesis for the origin of some families, while not contradicting that hypothesis for any family.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 32; Oct. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 187
    facet.materialart.
    Unbekannt
    Apollo 14 coarse fines (4-10 mm) sample location and classification (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The 4 to 10 mm sieve fraction from the soil samples collected during the Apollo 14 Mission was identified and described. Examination and description of the fines were carried out in nitrogen-filled, stainless steel cabinets during a general examination of the Apollo 14 sample collection. Each particle was held between forceps, dusted in a jet of N2, and placed on a teflon-covered stage. They were examined with a binocular microscope, separated by lithology, and the lithologic types described. Weights of individual particles in the fraction ranged from about 0.10 to 0.50 gm, large enough in size for studies of age, chemistry, and petrology to be accomplished.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-TM-79348 , JSC-12992
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 188
    facet.materialart.
    Unbekannt
    Acceleration of protons at 32 Jovian radii in the outer magnetosphere of jupiter (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: During the inbound pass of Pioneer 10, a rapid ten-fold increase of the 0.2 to MeV proton flux was observed at 32 Jovian radii (R sub J). The total event lasted for 30 minutes and was made up of a number of superimposed individual events. At the time, the spacecraft was in the outer magnetosphere about 7 R sub J below the magnetic equator. Before and after the event, the proton flux was characteristic of the low flux level normally encountered between crossings of the magnetic equator. Flux changes at different energies were coherent within 1 minute; a time comparable to the time resolution of the data. The angular distributions were highly anisotropic with protons streaming towards Jupiter. A field-aligned dumbbell distribution was observed initially, and a pancake distribution just before the flux decayed to its pre-event value. The alpha particle flux changed as rapidly as the proton flux but peaked at different times. The energetic electron flux behaved differently; it increased gradually throughout the period.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-TM-X-71410 , X-660-77-225
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 189
    facet.materialart.
    Unbekannt
    The origin of the grooves on Phobos (1977)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Various theories for the long, linear depressions on the surface of Phobos are reviewed. Imagery from Viking Orbiters is used to map the surface distribution of the grooves, study their morphology, and date them by means of the density of superimposed impact craters. Data is presented which tends to support the hypothesis that the deep-seated fracturing was caused by a large, nearly catastrophic cratering event. It is suggested that the grooves were produced during the creation of the Stickney crater, rather than as the result of tidal stresses induced by Mars or by drag forces during the hypothetical capture of the satellite by Mars.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA-CR-157998 , CRSR-679
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 190
    facet.materialart.
    Unbekannt
    Basalts from Mare Crisium (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The stratified core sample returned from Mare Crisium by the Luna 24 unmanned space probe is composed primarily of a variety of subophitic to ophitic basalt with very low contents of TiO2 and MgO. This consists of clinopyroxene, calcic plagioclase, olivine, and minor amounts of silica, chromite, ulvoespinel, ilmenite, troilite, apatite, and Fe-metal. Granular metabasalts have the same bulk composition, but mineral phases exhibit less compositional variation. Fine-grained impact melts have similar compositions and are apparently derived from these basalts. It is concluded that the basalts, which are chemically distinct from the very-low-titanium basalts found elsewhere on the moon, represent the local surface flows of Mare Crisium. Sparse fragments of an olivine vitrophyre that is low in TiO2 but high in MgO and approaches the composition of the Apollo 15 green glasses may be derived from patches of dark mantling materials 20 km from the landing site.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: The Moon; 17; Nov. 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 191
    facet.materialart.
    Unbekannt
    The use of surface reflections in lunar seismograms (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The use of polarization filters is demonstrated on lunar seismograms. Body-wave arrivals from artificial impacts are identified as surface reflections, which may be used for improving our knowledge of the lunar interior or to relocate surface events if an approximate location is known as well as an approximate model.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Seismological Society of America; vol. 67
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 192
    facet.materialart.
    Unbekannt
    Lunar gravity - A long-term Keplerian rate method (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Nearside tracking data from Apollo subsatellites and Lunar Orbiter 5 are used to construct a model of the farside lunar gravity field. An indirect method of calculating the average effect of all the gravity anomalies which affect spacecraft orbits is reduced to a linear estimation problem by eliminating the integration of spacecraft dynamics. Doppler frequency shifts between the lunar satellite and earth-based tracking station are used to measure the line of sight velocity component between the orbiter and the tracker; gravity determination is then performed in a weighted least squares estimator which employs the orbital rates as data and formulates the normal equations using the associated Keplerian state. Simulations performed demonstrate that farside gravity features can be economically determined by use of gravity estimates obtained from long-period models of nearside orbiting tracks.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; July 10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 193
    facet.materialart.
    Unbekannt
    Lunar gravity - A harmonic analysis (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A sixteenth-degree and sixteenth-order spherical harmonic lunar gravity field has been derived from the long-term Keplerian variations in the orbits of the Apollo subsatellites and Lunar Orbiter 5. This model resolves the major mascon gravity anomalies of the lunar near side and is in very good agreement with line-of-sight acceleration results. The far-side map shows the major ringed basins to be strong localized negative anomalies located in broad regions of positive gravity which correspond closely to the highlands. The rms pressure levels calculated from equivalent-surface height variations show that the moon and earth support nearly equal pressures, whereas Mars is appreciably stronger. The moon appears to support larger loads than earth owing to its weaker central gravity field and perhaps a colder upper lithosphere. Significant differences between the low-degree gravity and topography spectra indicate that the longer-wavelength topographic features are isostatically compensated.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 82; July 10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 194
    facet.materialart.
    Unbekannt
    Calculations of the effects of angular momentum on the early evolution of Jupiter (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Early phases in the evolutionary development of a rotating cloud of gas and dust are investigated to determine whether physically reasonable initial conditions are likely to produce a planet-satellite system with the values of specific orbital angular momentum currently observed for Jupiter and its inner satellites. Spherically symmetric computations of Jupiter's evolutionary history are reviewed, and transport of angular momentum is considered along with evolutionary sequences of individual differentially rotating models with decreasing values of equatorial radius. The problem of accounting for the present specific orbital angular momenta of Jupiter and its regular satellites is examined qualitatively, and a range of possible angular-momentum distributions in an initially tidally unstable cloud is assessed. The results show that particular physically plausible angular-momentum distributions, which could either be established as initial conditions or be caused by angular-momentum transport, will lead to favorable situations for the formation of a central planet and a surrounding rotating cloud with specific angular momentum comparable to that of the regular satellites.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 31; July 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 195
    facet.materialart.
    Unbekannt
    Far-infrared and submillimeter observations of the planets (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Broadband observations in several passbands between 30 and 500 microns of Mercury, Venus, Mars, Jupiter, Saturn, and Uranus are presented. The best agreement between the data and various thermal models of Mars, Jupiter, and Uranus is obtained with a slightly cooler absolute temperature scale than that previously adopted by Armstrong et al. (1972). The effective temperature of Uranus is 58 + or - 2 K, which is in agreement with its solar equilibrium temperature. The existence of an internal energy source for Saturn has been reconfirmed; its output must lie within the range of 0.9 to 3.2 times the absorbed solar flux. A depression exists in the spectra of Jupiter, Saturn, and Uranus between 80 and 300 microns, which may be a result of NH3 opacity.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 31; July 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 196
    facet.materialart.
    Unbekannt
    Photometric imaging of Mars during the 1973 opposition (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The paper discusses imaging of Mars at 20 wavelengths in the spectral region from 0.35 to 1.10 microns performed during the 1973 opposition with a photometric imaging system that uses a silicon vidicon tube as the detector. The imaging system and data-reduction procedures are described in detail, and relative reflectance spectra for several small areas in the images are presented along with vidicon images obtained during early phases in the development of the 1973 dust storms. Several anomalous blue brightenings are examined and attributed to ground fog and H2O frost. It is suggested that anomalously large amounts of H2O were pulsed into the atmosphere from the regolith by the storm system. An apparent fading and recession of the north polar hood is noted, surface units revealed in contrast-enhanced ratio images are identified, and the need for higher-spatial-resolution orbital spectroscopy of dark areas is emphasized.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 31; July 197
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 197
    facet.materialart.
    Unbekannt
    Uranus - Limb and polar brightening at 7300 A (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: Pinhole photoelectric area-scanning photometry of the Uranus disk demonstrates directly the existence of both limb and polar brightening in the 7300 A CH4 band. Polar brightening, which appears to be present also at continuum wavelengths, is interpreted as being caused by scattering in a thin aerosol haze located over the polar region.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysical Journal; vol. 214
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 198
    facet.materialart.
    Unbekannt
    Photometry of the Gallilean satellites (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: The dependence of the magnitudes and colors on both solar and orbital phase angles is derived from photometric observations of the Gallilean satellites. The rotational variations are best defined by the most recent observations; as a consequence of the complex albedo distributions on the satellites, the light curves cannot be represented by simple analytic expressions. The recent data also establish the mean magnitudes on the V photometric system to within + or - 0.02 magnitude and permit accurate geometric albedos to be derived. The dependence of magnitude on solar phase angle, and particularly at very small phase angles, is best shown by the extensive observations from 1926 and 1927. The determined rotational curves are used to reduce these data and express the phase effect in terms of a linear curve for phase angles greater than 6 deg and a quadratic curve for smaller angles. The phase dependence of these satellites is compared with that observed for other small bodies in the solar system; particularly interesting are the anomalously large phase coefficient and opposition effect of Io.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 199
    facet.materialart.
    Unbekannt
    Photometry of satellite surfaces (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A review is presented of basic photometric concepts as they apply to the study of the surfaces of natural satellites. The analysis of brightness variations related to changes in solar phase angle, the longitude of the satellite in its orbit about the primary, and other factors is discussed, together with the derivation of phase integrals. The method used to determine geometric albedos is outlined, and major uncertainties in determined values are considered. Photometric results obtained for satellites of Mars and Jupiter are summarized. Leading side/trailing side brightness trends characteristic of the inner satellites of these planets and lightcurve color amplitude trends are examined. Priority areas for future photometric studies are identified.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 200
    facet.materialart.
    Unbekannt
    Satellite spectrophotometry and surface compositions (1977)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-27
    Beschreibung: A summary of available spectrophotometric data for planetary satellites is presented. Most data given is for the 0.3 to about 3 micron spectral region. The spectrophotometric results are compared with spectral reflectivity curves of cosmologically abundant substances to provide information on the possible composition of surfaces of planetary satellites, excluding earth's moon. Water ice and other frosts appear to be common in the outer solar system; however, most surface compositions cannot be unambiguously defined.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...