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Muehlberger, W. R.

Publications and source records attributed to Muehlberger, W. R..

11 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Geology of the Apollo 17 site

The Apollo 17 landing site was unique in several aspects: (1) it was the only site that was not selected from telescopic-based geologic interpretation--interest in the site was generated by the visual observations of Al Worden, Apollo 15 Command Module pilot, who interpreted dark-haloed craters as possible cinder cones; (2) instead of 20-m-resolution photographs, as was the norm for all earlier missions, this site had Apollo 15 panoramic camera photography coverage that had 2-m resolution; and (3) it had a geologist-astronaut aboard who was intimately involved in all stages of planning and mission operation, and was also instrumental in the design of a long-handled sample bag holder that eliminated the need for crew to dismount before collecting a sample, which then permitted sampling between major stations. Details of site geology, sample description, and geologic synthesis of the site as viewed from studies through 1976 are summarized.

Muehlberger, W. R.↗
NASA NTRS1980

Mission objectives for geological exploration of the Apollo 16 landing site

The objectives of the Apollo 16 mission to delineate the nature and origin of two major physiographic units of the central lunar highlands are discussed. Surface exploration plans, specific sampling procedures, operational constraints, and suites of samples that were collected for specific local objectives are described. Pre-mission hypotheses that favored a volcanic origin for the Cayley plains as well as the Descartes mountains were proved to be wrong by the mission results, but not enough samples have been studied to draw any other definite conclusions. Two contrasting schools of thought about the origin of the Apollo fragmental impact deposits are described: one maintains that the samples are predominantly of local origin, while the other suggests more distant, basin-related sources.

Muehlberger, W. R.↗
NASA NTRS1978

Lunar mare ridge orientation - Implications for lunar tectonic models

Four circular mare basins were selected for ridge orientation analysis: Crisium, Imbrium, Serenitatis and Tranquillitatis. In each basin a central area was identified in which ridges were neither concentric with basin edges nor seemed to be extensions of significant highland structural trends. Ridge orientations in these central areas and in the remaining marginal areas were measured separately and rose diagrams plotted for each. Rose diagrams of ridge orientations in the four circular mare basins show a narrow dispersion with a statistical average nearly north. Trends of basin margin ridges have a high deviation and are polymodal with maxima in the northwest, north and northeast directions. Mare ridges which display a preferred northern trend result from an east-west compressive stress field.

Fagin, S. W.↗
NASA NTRS1977

The Shuttle era - A challenge to the earth scientist

Satellite observations of large-scale earth features and phenomena, with either instruments or astronauts, are discussed on the basis of earlier experience (mainly Skylab). Off-nadir views and photographs by astronauts have provided valuable supplements to instrument nadir views, providing cross-checks through remote sensing at different angles, different altitudes, and in different seasons. New information on plate tectonics, global cooling/drying trends, global oceanographic data (changing positions of major ocean current patterns, evolution of warm and cold eddies and their relation to sea temperatures and concentrations of marine fauna, location of internal sea waves, interactions between ocean currents and atmosphere, plankton blooms), storm development, snow cover patterns, lake and sea ice growth, sand-dune patterns, desert storms blown out to sea, effects of grazing and swidden agriculture, and other earth features and phenomena are surveyed.

Muehlberger, W. R.↗
NASA NTRS1974

Structural history of southeastern Mare Serenitatis and adjacent highlands

Deformational events are identified from Apollo 17 low-sun photographs of southern Mare Serenitatis and the adjacent Taurus-Littrow region. Analysis of the data indicates that the rate of deformation, including subsidence of the Serenitatis basin, has decreased through time as the crust increased in strength. Three main basalt sequences are found: one each at 3.8, 3.5, and 3.2 b.y. Wrinkle ridges began forming at about 2.5 b.y.; asymmetrical scarps also formed much later than the deformations.

Muehlberger, W. R.↗
NASA NTRS1973

Preliminary geologic investigation of the Apollo 17 landing site

A geological investigation of the Apollo 17 lunar landing site was conducted. The Taurus-Littrow valley is interpreted as a deep graben formed by structural adjustment of lunar crustal material to the Serenitatis impact. Materials of the valley fill were sampled at many stations. Ejecta around many craters on the valley floor consist of basalt, showing that the graben was partly filled by lava flows. The geological objectives of the Apollo 17 mission are divided into orbital and lunar surface data collection. The data obtained for both types of investigation are presented in tables, photographs, and drawings.

Muehlberger, W. R.↗
NASA NTRS1973

Basalt stratigraphy of southern Mare Serenitatis

The major features of the stratigraphic and structural sequence are summarized for Mare Serenitatis. The dark oldest basalts include flows coextensive with Mare Tranquillitatis and also flows and pyroclastic deposits (dark mantles) that erupted from the edge of the Serenitatis basin. The basin sagged, possibly isostatically, as basalts of intermediate age were emplaced. Sagging had nearly ceased by the time the youngest flows were deposited. Compressive movements including thrusting followed, and small extensional fissures formed in late Copernican time. The revised stratigraphic sequence that was elaborated has implications for lunar stratigraphy that transcend the boundaries of Mare Serenitatis. Dark mantle deposits and the darkest maria have commonly been assumed in geologic mapping to be relatively youthful. These assumptions must now be reevaluated and perhaps discarded.

Howard, K. A.↗
NASA NTRS1973

Lunar thrust faults in the Taurus-Littrow region

Evidence, suggesting that wrinkle ridges and similar looking one-sided scrapes in the Taurus-Littrow region are caused by anticlines and thrust faults resulting from sliding on a flowing surface, is given.

Howard, K. A.↗
NASA NTRS1973

Geologic setting of Apollo 16

Prior to the Apollo 16 mission, the materials of the Cayley Plains and the Descartes Mountains were thought to be mostly of volcanic origin. Rock and soil samples from these regions strongly suggest, however, that they may be products of multiring basin forming impacts, although minor local volcanism is not precluded. The smooth planar surfaces may have been formed initially by Imbrium ejecta which flowed into topographic lows at the distal margins of the lineated Fra Mauro ejecta. It is emphasized, however, that the rocks and soils returned from the Apollo 16 site cannot necessarily be considered representative of the lunar crust in the Descartes region from which they were collected.

Hodges, C. A.↗
NASA NTRS1972

Preliminary geologic investigation of the Apollo 16 landing site

Preliminary results of examining the lunar rock samples from the Apollo 16 flight are reported. Topics discussed include: premission geologic studies, geologic objectives, description of the site and traverse routes, superficial deposits, and station descriptions.

Muehlberger, W. R.↗