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Adams, J. B.

Publications and source records attributed to Adams, J. B..

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Geochemical and geological units of Mare Humorum - Definition using remote sensing and lunar sample information

Mare Humorum has been found to contain at least nine distinct units. Mare basalt units typical of those at the Apollo 12 and 15 sites and central Mare Serenitatis exist also in Mare Humorum, but the early, high-titanium basalts typical of Mare Tranquillitatis and southeast Mare Serenitatis are absent. Basalts containing about 5% TiO2, not sampled at any Apollo site, also are found in Mare Humorum. Emplacement of extensive low-titanium basalts occurred in Mare Humorum in roughly the same period as emplacement of similar basalts at Apollo 12 and central Mare Serenitatis. These were followed by emplacement of the higher titanium basalts during a later period. These and other units are characterized and their extent mapped using a combination of remote sensing and Apollo sample studies. The results are interpreted in the context of the evolution of the Humorum region.

Pieters, C.↗
NASA NTRS1974

Lunar surface - Identification of the dark mantling material in the Apollo 17 soil samples

Evidence indicates that Apollo 17 sample 74001, a soil consisting of very dark spheres, is composed almost entirely of the dark mantling material that covers a large region of the southeastern boundary of Mare Serenitatis. Other Apollo 17 samples contain only a component of this material. The underlying basalt in the Taurus-Littrow valley appears to be an extension of material forming the low-albedo ring around part of Mare Serenitatis and much of the surface of Mare Tranquillitatis. The surface of this basalt region is spectrally distinct from areas with dark mantling material. These results are derived from telescopic and laboratory measurements of the optical properties of lunar soil. Digital vidicon color images are used to map the extent of these material units in the Taurus-Littrow region.

Pieters, C.↗
NASA NTRS1974

Spectral reflectance of 72275 from Boulder 1, Station 2, Apollo 17

Spectral reflectance measurements were made of samples 72275,103 (chip) and 72275,98 (saw cuttings). Both the chips and the cuttings consist mainly of friable feldspathic breccia. Sample 72275,103, a chip taken from eastend piece 72275,27, is rich in gray polymict breccia. The saw cuttings were derived from the entire rock, but they are probably strongly biased toward the friable feldspathic matrix material that has been preferentially disaggregated. The spectra of both samples show two prominent absorption bands arising from Fe2(+) in pyroxene. The depths of these bands are large enough to preclude the presence of much glass or opaque material in the samples. From the spectral properties alone, it is clear that the samples are not soil breccias nor vitric breccias, as, of course, has been verified by petrography. The wavelengths of the principal absorption bands plot on the pyroxene trend, indicating that orthopyroxene is spectrally dominant.

Adams, J. B.↗
NASA NTRS1974

Orange glass - Evidence for regional deposits of pyroclastic origin on the moon

Crystallized spheres of orange glass from Shorty Crater at the Apollo 17 site are shown by spectral reflectance data to be the characteristic ingredient of the dark mantling deposit of the Taurus-Littrow region. This deposit, mapped on spectral vidicon images taken using earth-based telescopes, apparently is thickest 50 km northwest of the Apollo 17 landing area, and has a gradational contact with the surrounding materials. The irregular areal distribution of the dark-mantle deposit and the gradational borders support conclusions based on laboratory studies of the orange soils that these are volcanic pyroclastic materials. Similar deposits are identified by spectral reflectance properties near Rima Bode, Schroeter W, Fauth H, and Higinus W. The same material is likely to occur at Sulpucius Gallus based on visual and photographic observations of orange soil. The apparently restricted occurrence of the orange-glass deposits in a belt along the edges of major mare basins implies structural control of volcanic vents and a possible deep-seated origin.

Adams, J. B.↗
NASA NTRS1973

Lunar black spots and nature of the Apollo 17 landing area.

A few small areas on the moon with extremely low albedo are shown also to have similar spectral reflectivity and radar backscatter characteristics. These lunar 'black spots' include the dark mantling material of the Apollo 17 landing site as well as areas of the Sulpicious Gallus formation. Excluded from the black spot group are the dark haloed craters of Alphonsus and the normal dark mare areas such as northern Mare Tranquillitatis. Earth-based radar and optical measurements indicate that these lunar black spots have rock-free surfaces with a very low proportion of crystalline material to amorphous material. The glassy soil is rich in iron and titanium, at least to the concentrations found at the Apollo 11 site. Crystalline pyroxene is present also. The data for the black spots are consistent with a mantling material of ash or cinder.

Pieters, C.↗
NASA NTRS1973

Visible and near-infra-red transmission and reflectance measurements of the Luna 20 soil.

Visible and near-infrared spectra of chemically analyzed grains of glass and minerals from the Luna 20 sample were compared with diffuse reflectance spectra of the bulk soil. As in the spectra of soil samples from other localities on the moon, pyroxene contributes two broad absorption features near 1 and 2 microns. The soil has a high integral reflectance (or albedo) arising from plagioclase, which appears to be the dominant mineral in the lunar highlands. The Luna 20 soil curve is most similar to the reflectance curves of the non-rayed soils at Apollo 16, in agreement with the generally similar mineralogy of these samples. The average pyroxene composition in the Luna 20 soil, as determined from the absorption bands in the diffuse reflectance spectra, and analyses of single crystals, is more calcic than in the lithic fragments. Thus, the soil appears to have a few per cent of admixed material derived from mare basalts. Comparison of the soil spectrum with telescopic curves of nearby areas reveals a close similarity.

Adams, J. B.↗
NASA NTRS1972

Mercury - Interpretation of optical observations.

The spectral reflectivity of Mercury has constant positive slope from 0.32 to 1.05 microns, except for the possibility of an absorption feature in the infrared. The reflectivity curve matches closely the curve for lunar upland and mare regions. Thus, the surface of Mercury is probably covered with lunar-like soil rich in dark glasses of high iron and titanium content. If the absorption band is real, pyroxene is the dominant mafic mineral.

Mccord, T. B.↗
NASA NTRS1972

Mercury - Surface composition from the reflection spectrum.

The reflection spectrum for the integral disk of the planet Mercury was measured and was found to have a constant positive slope from 0.32 to 1.05 micrometers, except for absorption features in the infrared. The reflectivity curve matches closely the curve for the lunar upland and mare regions. Thus, the surface of Mercury is probably covered with a lunar-like soil rich in dark glasses of high iron and titanium content. Pyroxene is probably the dominant mafic mineral.

Mccord, T. B.↗
NASA NTRS1972

Lunar spectral types.

Results of observations of the spectral reflectance properties (0.3 to 1.1 micron) of a number of lunar mare, upland, and bright crater areas with the use of ground-based telescopes. These new data are discussed in view of earlier studies in an attempt to provide a basis for more detailed interpretation. The spectral reflectivity curves (0.3 to 1.1 micron) for all lunar areas studied consist of a positive sloping continuum with a superimposed symmetric absorption band centered at 0.95 micron. Upland, mare, and bright crater materials can be identified by their spectral curves. The curves for upland and mare regions show a range of shapes from fresh, bright craters to progressively darker background material that correlates with the apparent age of the surface features. The observed upland material has uniform spectral properties, but the mare material shows some variety, probably due to Ti(3+) dispersed in lunar-soil glass. Copernicus and Aristarchus appear to have exposed upland material from beneath the mare but Kepler has not. This observation suggests that the mare is no deeper than about 15 km in the Copernicus area and about 6 km deep in the Aristarchus area, but in the Kepler area the mare must be at least about 5 km deep.

Mccord, T. B.↗