Search NASA⌕ Search

SEARCH · Search NASA

Results for “Luna”

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

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

An investigation of the cosmic radiation in the vicinity of the moon on the Luna 10, 11, and 12 artificial lunar satellites

Research on the primary cosmic radiation and solar cosmic rays from the Luna 10, 11, and 12 artificial lunar satellites is reviewed. Data on the vertical distribution of cosmic rays above the moon's surface are presented, and the albedo for the primary radiation is determined. The fluxes of electrons with energies from 30 to 300 keV were registered in the solar cosmic rays. Rapid variations of the electron flux were observed. The angular distributions of 0.5-10 MeV protons moving together with the corpuscular streams responsible for Forbush decreases were investigated.

Grigorov, N. L.↗
NASA NTRS1974

Mineralogy, petrology, and chemistry of basalt fragments returned by Luna 16

Mineralogical, petrological, and chemical analyses, along with Rb-Sr age and Ar-40/Ar-39 measurements, were carried out with the B-1 sample returned from the Luna 16 mission. The sample, weighing 62 mg, is a fine-grain basalt of ophitic structure. It differs from the Apollo samples in that the pyroxene and plagioclass contents are almost identical, and the ilmenite content (7%) lies between those of the Apollo-11 and Apollo-12 samples. Chemically, it is characterized by a high Sr content and a high K/U ratio.

Albee, A. L.↗
NASA NTRS1974

Investigation of a glass spherule from the Luna-16 probe

A glass spherule of the form of a flattened spheroid measuring 580 microns in diameter is studied. The spherule is transparent, shiny, and of a yellowish brown tint. It contains a number of central and peripheral spherical bubble-type cavities. The surface and morphology features resemble those of Apollo spherules, but differ in chemical composition, which is close to that of the Luna-16 regolith.

Glass, B. P.↗
NASA NTRS1976

Composition and origin of Luna 16 aluminous mare basalts

The mineralogy and petrology of 58 lithic fragments, 52 of which are basaltic, in the Luna 16 samples were studied, with textures, and mineral and bulk compositions determined by petrographic and electron microprobe techniques. These mare basalt fragments differ from other mare basalts in being aluminous (11-20%) which results in plagioclase and (olivine) microphenocrysts; moreover, they have very low-FeO and MgO and high-CaO, FeO/MgO, and normative diopside contents.

Kurat, G.↗
NASA NTRS1977

Investigation of the composition of the Luna 16 lunar sample

The concentrations of aluminum, manganese, sodium, chromium, iron, cobalt, and 12 rare earth elements were determined by neutron activation analysis using slow neutrons. Oxygen and silicon were determined using a fast neutron generator. Mossbauer spectroscopy was used to investigate iron compounds in Luna 16 regolith samples from the upper part of the core.

Bakos, L.↗
NASA NTRS1977

Results of special mechanical analyses of Luna 16 material

The studies carried out on the Luna 16 regolith have confirmed the data that were already published internationally. By means of activation analysis under irradiation in the reactor, activation analysis with a 14 MeV U-generator, and mass spectroscopy on samples of 10 or 20 mg, six main and 63 trace elements were quantitatively determined and compared with known data.

Stiller, H.↗
NASA NTRS1977

Metallic phases in the Luna 24 soil samples

The metal and sulfide phases in the Luna 24 soil samples were studied with the optical microscope and the electron microprobe. The compositions of the metal particles fall into three groups based on their Ni and Co contents: (1) Samples of meteoritic composition which have undergone metamorphism on the lunar surface. (2) Samples of submeteoritic, low Ni and low Co contents, including most of the metal particles observed. These particles are contained in glass and agglutinate particles and were probably formed by the mixing of meteoritic metal with lunar metal produced by the reduction of silicates during shock-impact. (3) Samples of high-CO content probably formed by mixing of meteoritic material with high-Co metal from the mare basalt or by fractional crystallization from a metal silicate melt. The sulfide minerals were also studied. These are almost pure FeS, and crystallized from a late stage liquid in the mare basalt. Three high-Ni sulfides were also found in the glass phase of agglutinates.

Friel, J. J.↗
NASA NTRS1977

High-silica glass inclusions in olivine of Luna-24 samples

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.

Roedder, E.↗
NASA NTRS1978

Particle track densities in the Luna 24 core

We report track density measurements in soil grains at six locations in the Luna 24 core. Irradiation levels are generally high precluding information on the depositional history, but indicating that the soils were exposed at the lunar surface at sometime in the past. Maturity levels determined from track density parameters disagree with those determined from ferromagnetic resonance and agglutinate contents. This discrepancy is not understood, but it could possibly indicate an ancient epoch of increased solar-flare activity.

Blanford, G. E.↗
NASA NTRS1978

Nuclear particle tracks and the regolith at the Luna 24 site

Track investigations of feldspars and pyroxenes in Luna 24 soils indicate that most of the grains resided within millimeters of the lunar surface. The two deepest samples appear to be less mature than the upper ones. Lack of correlation between tracks, agglutinates, and I sub S/FeO is puzzling and unique.

Crozaz, G.↗
NASA NTRS1978

Origin and modal petrography of Luna 24 soils

Petrographic modal analyses of polished grain mounts of fractions in the 20 to 250 micron size range from Luna 24 soil samples are presented and used to infer the nature and relative contributions of source rocks. It is found that more than 90% of the identifiable rock fragments are mare basalts, with about 11% of the soil consisting of the crystalline form. Soil breccias, which make up nearly 10% of the soil, are found to be immature. Electron probe analysis of glass particles reveals principle clusters conforming to anorthosite, anorthositic gabbro and mare basalts. More than half of the soil is composed of monomineralic particles, with pyroxene as the most abundant mineral. It is concluded that 85% of the regolith is derived from local mare basalts and gabbros and about 10% is derived from early cumulates of local mare basalt magma. Highland sources are considered to contribute not more than 3% of the regolith.

Basu, A.↗
NASA NTRS1978

On the origin of Luna 24 basalts and soils

Analyses of fine-grained very low titanium (VLT) basalt from the Luna 24 drill core suggest that a single homogeneous magma is represented by the sample. In particular, the small variation in MgO contents of the fine-grained basalt, together with the tight clustering of the compositions of brown glasses (which may be pyroclastic equivalents of the VLT basalt), provides evidence for the single-magma hypothesis. The high-Mg component in the soil samples, though not obviously explainable in petrographic terms, may be derived from material similar to olivine vitrophyre and its degraded products, or from some other high-Mg VLT basalt.

Ryder, G.↗
NASA NTRS1978

Mineralogy and petrology of basaltic fragments from the Luna 24 drill core

The petrology of rock fragments and monomineralic grains from Luna 24 samples is described, and a petrogenetic scheme for the derivation of Mare Crisium basalts is presented. Components of the rock fragments include subophitic basalts, metabasalts, late-stage fragments, olivine vitrophyres, and non-mare lithic fragments of possible cumulate origin. Among the monomineralic grains (which are much more abundant than the rock fragments) are pyroxene, plagioclase, olivine, ilmenite and native Fe.

Coish, R. A.↗
NASA NTRS1978

The case for at least three mare basalt magmas at the Luna 24 landing site

Petrographic and electron microprobe studies have been carried out for 1230 particles from the Luna 24 drill core. At least three mare basalts were distinguished on the basis of major and minor element chemical compositions of pyroxenes. Mg-rich monomineralic particles of olivine and pyroxene defined one major type. The other two magmas were identified by the Ti/(Ti + Cr) ratio at constant Fe/(Fe + Mg) ratio in pyroxenes derived from polymineralic igneous lithic fragments. Whole rock chemical analyses for V and Cr also provided evidence for these distinct magmas.

Nielsen, R. L.↗
NASA NTRS1978

Major and trace element chemistry of Luna 24 samples from Mare Crisium

Atomic absorption spectrometry and instrumental neutron activation analysis were employed to analyze six Luna 24 soils for major and trace elements. The analysis revealed well-mixed soils, though size fractions of each of the soils showed quite dissimilar compositions. Thus the regolith apparently has not been extensively reworked. Noritic breccia admixed preferentially to the finest size fractions and differential comminution of one or more other soil components accounted for the observed elemental distributions as a function of grain size. The ferrobasalt composition and one or more components with higher MgO contents have been identified in the samples.

Blanchard, D. P.↗
NASA NTRS1978

Chemical and Sr-isotopic characteristics of the Luna 24 samples

The chemical and Sr isotopic characteristics of Luna 24 bulk soil samples are determined and interpreted within the framework of lunar mare basalt evolution. Major and trace element compositions lead to the suggestion of candidate rock types consisting of a basalt/gabbro with very low TiO2 and MgO content (52%), a very low TiO2 basalt with 10% MgO (23%), olivine vitrophyre (20%), low K Fra Mauro basalt (4%) and anorthositic gabbro (1%). The proposed compositions are supported by the agreement of mixing models based on the proposed compositions with observed soil compositions. Sr ratios for plagioclase samples imply a lower Sr-87/Sr-86 value for low Mg soils than for other mare basalts and higher Rb/Sr and a more evolved Sr ratio in high Mg basalts. Rb, Sr and rare earth element compositions for low Mg basalts fit a model of partial remelting of cumulates containing small amounts of plagioclase.

Nyquist, L. E.↗
NASA NTRS1978

Petrology, chemistry, age and irradiation history of Luna 24 samples

The results of petrological, chemical, isotopic age determination and irradiation studies of sample 24170 from the 170 cm depth of the regolith core returned from Mare Crisium by Luna 24 are presented. The sample is found to be comprised of fragments from a single igneous rock, with mineralogical evidence indicating it to be a mare basalt. The crystallization age is determined by Sm-Nd and Ar(40)-Ar(39) ages to be 3.30 AE, establishing the presence of relatively young flows. All soil samples show low trace element compositions with minimum contamination by KREEPUTh-rich materials. Rb-Sr and Sm-Nd relations reflect the absence of significant fractionation at ages younger than 4.5 AE. One soil sample shows extremely large neutron capture effects, imposing a new lower limit to the neutron production rate in the regolith and requiring the addition of irradiated materials from depth.

Wasserburg, G. J.↗
NASA NTRS1978

Clast-laden nature and the origin of Luna 24 olivine-vitrophyres

The study shows that Luna 24 olivine-vitrophyric particles are actually fragments of clast-laden melt and are not from a very low titanium (VLT) mare basalt flow. Diversity of composition and clast population, and morphological similarity to ropy glasses suggest an impact melt origin. Compositionally, the olivine-vitrophyres resemble the high magnesian VLT basalts, which may have been the target and source of the impact melt.

Basu, A.↗