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El-Baz, F.

Publications and source records attributed to El-Baz, F..

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Earth observations and photography experiment: Summary of significant results

Observation and photographic data from the Apollo Soyuz Test Project are analyzed. The discussion is structured according to the fields of investigation including: geology, desert studies, oceanography, hydrology, and meteorology. The data were obtained by: (1) visual observations of selected Earth features, (2) hand-held camera photography to document observations, and (3) stereo mapping photography of areas of significant scientific interest.

El-Baz, F.↗
NASA NTRS1978

The meaning of desert color in earth orbital photographs

The color of desert surfaces as seen in earth orbital photographs is indicative of soil composition. Apollo-Soyuz photographs of the Sturt and Simpson Deserts of Australia confirm that sand grains become redder as the distance from the source increases. Reddening is caused by a thin iron-oxide coating on individual sand grains and can be used, in some cases, to map relative-age zones. Photographs of the Western (Libyan) Desert of Egypt indicate three distinct and nearly parallel color zones that have been correlated in the field with: (1) arable soil composed of quartz, clay, and calcium carbonate particles; (2) relatively active sand with or without sparse vegetation; and (3) relatively inactive sand mixed with dark (desert-varnished) pebbles. The youngest sands are in the form of longitudinal dunes, which are migrating to the south-southeast along the prevailing wind direction. Some of the young dune fields are encroaching on the western boundary of the fertile Nile Valley.

El-Baz, F.↗
NASA NTRS1978

The nature of rays and sources of highland material in Mare Crisium

Although highland fragments are rare in the Luna 24 core, they should provide an important source of information on the sequence of formation and lithology of lunar east-limb basins. The numerous rays that cross the Crisium basin suggest several sources of highland materials. Both deposition of primary ejecta and reworking of local material were most likely responsible for the formation of ray systems in Mare Crisium. In addition to the fact that Luna 24 landed near the uprange end of a Giordano Bruno ray, incomplete sampling of the uppermost layer and formation of the ray by reworking of in situ regolith suggest that its materials may be scarce or not present in the core. Highland fragments present are most likely to be representative of several highland sources.

Maxwell, T. A.↗
NASA NTRS1977

Topography of sinuous rilles in the Harbinger Mountains region of the moon

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.

Strain, P. L.↗
NASA NTRS1976

Earth observations and photography experiment MA-136

The primary objectives of the earth observations and photography experiment of the Apollo Soyuz Test Project were to photograph various terrestrial structures and to use the capabilities of man as a trained observer in visually studying earth features and phenomena. Man's special capabilities include the sensitivity of the eye to subtle color variations and the speed with which the eye/brain system can interpret what is seen and select targets for photography. Real time astronaut observations constitute a useful complement to orbital photographs and greatly aid in their interpretation. Targets for mapping and hand held photography were selected on the basis of their value to specialists in the earth sciences including geology, oceanography, desert study, hydrology, meteorology, and environmental science.

El-Baz, F.↗
NASA NTRS1976

Photogeology of the multi-ringed crater Haldane in Mare Smythii

Haldane is a 40 km multi-ringed crater that occurs along with similar structures in a belt within the Smythii Basin. It is the best developed structurally of all craters in this belt and displays examples of all materials units of Mare Smythii. In addition to the outer rim, the crater displays a sharp-crested, nearly complete inner ring, and a complex central peak of round hills that are 300-600 m higher than the floor. There are two fracture systems associated with Haldane, one annular and the other radial. The annular fractures seem to control the deposition of mare basalts and dark mantle units in and around the crater. Topographic evidence and flow scarps indicate that the crater was the source of mare basalts and associated dark mantle, rather than its being flooded by such deposits. There are numerous indications that most of the features in and around Haldane are attributable to volcano-tectonic modifications of an original crater-form.

Wolfe, R. W.↗
NASA NTRS1975

Distribution, morphology, and origin of ridges and arches in Mare Serenitatis

Lunar mare ridges and arches in Mare Serenitatis were mapped to understand better their mode of formation. Maps of these features indicate that several pre-mare impacts in the Serenitatis area may be responsible for the localization of the circular ridge systems and that the subsurface, pre-mare topography is more complex than previously recognized. Apollo Lunar Sounder cross sections of ridge systems in southern Serenitatis indicate 50 to 100 m of local relief on these features. Small-scale features of ridges, such as medial lineations and lobate margins, do not conclusively define the origin of the ridges. However, estimates of crustal shortening from Lunar Sounder data and the coincidence of the major ridge system with the Serenitatis mascon suggest that ridges and arches were formed by gravitational readjustments of the mare fill along four probable impact structures and along a north-trending fracture pattern.

Maxwell, T. A.↗
NASA NTRS1975

Photogeological, geophysical, and geochemical data on the east side of the moon

Correlations between Apollo orbital data and geologic data for eight map provinces are reported for a region centered on the east limb of the moon (50 deg N to 50 deg S and 50 deg E to 140 deg E). The appearance of the provinces is described, and the basins in or near the region are assigned relative ages. The western (nearside) part of the region averages about 3 km lower in elevation than the eastern (farside) part, according to laser altimeter measurements which are used to make geologic cross sections. Gravity data correlate with most geologic provinces and the surface profiles made by the laser altimeter and lunar sounder. The distribution of concentration ratios of Al/Si and Mg/Si as well as the distribution of relatively low natural radioactivity are considered.

El-Baz, F.↗
NASA NTRS1974

Surface geology of the moon

Questions regarding the formation of major lunar surface features are discussed, giving attention to the multiringed circular basins, the craters, and the mare material. Aspects of lunar stratigraphy are explored. At the present time, a lunar-wide time-stratigraphic sequence exists, in which surface units belong to one of a number of systems, including the Copernican, the Eratosthenian, Imbrian, Nectarian, and pre-Nectarian system. Details of Apollo surface exploration as conducted in each individual mission are considered along with the chemistry and the age of lunar materials, the lunar interior, and the evolution of the lunar surface.

El-Baz, F.↗
NASA NTRS1973

Geological observations from lunar orbit

The visual observations of the lunar surface from the command module of the Apollo 17 flight are presented. Detailed descriptions of the observation sites are given.

Evans, R. E.↗
NASA NTRS1973

Aitken crater and its environs

The physical characteristics of the fresh looking Aitken Crater and its surrounding environment are studied. Rim deposits and ejecta blanket indicate the crater has a probable impact origin or is formed during post-Aitken events. Data also indicate the crater's dark floor fill, its flow scarps, and smaller craters with domical structures are volcanic in origin. Landform varieties suggest episodic erruptions may also cause such craters.

El-Baz, F.↗
NASA NTRS1973

Observations of Mare Serenitatis from lunar orbit and their interpretation

Visual observations are investigated of color differences of Serenitatis mare materials from orbit complement photography and other remotely sensed data. The light tan gray inner fill of the Serenitatis basin is younger than the dark blue gray annulus; the latter continues into and appears to be contemporaneous with the fill of Mare Tranquillitatis. Mare ridges occur in both the inner basin fill and the dark annulus of Serenitatis. Ridges are interpreted as the result of structural deformation and up-doming after the solidification of the basaltic lavas. On the southeastern rim of the Serenitatis basin is the darkes blue gray unit within which Apollo 17 landed. Highland massifs surrounding this unit have unstable slopes which are believed to be the result of localized tectonic activity. On the southwest rim of the basin are the dark tan to brown gray mantling materials of the Sulpicius Gallus Formation. Farther west on the rim are dark blue grap patches which resemble the mare material of the Serenitatis dark annulus.

El-Baz, F.↗
NASA NTRS1973

Orbital observations of the lunar highlands on Apollo 16 and their interpretation

From orbital altitudes, the lunar highlands display the same surface characteristics on both the far and near sides. Rugged terra and plains forming materials all appear as if dusted with a uniform mantle. No stratigraphy or evidence of layering are seen in highland craters, with the possible exception of South Ray Crater in the Descartes landing site area. Among the discussed small scale features of the lunar highlands are: fine lineaments, that appear to be real rather than artifacts of lighting, on both horizontal and inclined surfaces; ridge-like scarps that cut across highland topography; and benches that are believed to be high lava marks rather than talus accumulates.

Mattingly, T. K.↗
NASA NTRS1973

Observations of Mare Serenitatis from lunar orbit and their interpretation

Visual observations of color differences of Serenitatis mare materials from orbit complement photography and other remotely sensed data. The light tan gray inner fill of the Serenitatis Basin is younger than the dark blue gray annulus; the latter continues into and appears to be contemporaneous with the fill of Mare Tranquillitatis. Mare ridges occur in both the inner basin fill and the dark annulus of Serenitatis. Ridges are interpreted as the result of structural deformation and up-doming after the solidification of the basaltic lavas. On the southeastern rim of the Serenitatis Basin is the darkest blue gray unit within which Apollo 17 landed. Highland massifs surrounding this unit have unstable slopes which are believed to be the result of localized tectonic activity. On the southwest rim of the basin are the dark tan to brown gray mantling materials of the Sulpicius Gallus Formation.

El-Baz, F.↗
NASA NTRS1972

Visual observations from lunar orbit, part A

Visual observations from Apollo 15 lunar orbits are discussed, complementing photographic and other remotely sensed data. Color tone of surface units, global tectonic trends, and small scale features are considered. Visual observations were made on Tsiolkovsky Crater, swirls in Mare Marginis, Picard Crater region, Proclus Crater, Littrow Crater area, landing site area, flow fronts in Mare Imbrium, and Aristarchus Plateau.

El-Baz, F.↗
NASA NTRS1972

Surface disturbances at the Apollo 15 landing site, part E

High resolution panoramic photographs taken from 110 km orbits of the command service module show the lunar module structure on the moon as evidenced by reflected light and by the shadow. Before and after photographs of the landing site are presented; the increased brightness or halo is attributed to mare surface materials.

Hinners, N. W.↗