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At least 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Differentiating elements of the soil-vegetation complex

The application of remote sensing to study soil-vegetation systems requires quantification and precise location of ground observation data such that they can be correlated with multispectral aerial acquired data. Griddling and sampling of an area for exact identification in a known address on magnetic tape containing multispectral scanner data produces quantitative physico-chemical parameters and the energy which is radiating from within the soil-vegetation complex of an area. Example classifications and spectral mappings of soils made from multispectral scanner data are included.

Baumgardner, M. F.↗
NASA NTRS1972

U-Th-Pb analyses of soil from the Sea of Fertility.

Analyses have been made of lead, uranium, and thorium in two soil samples from the Luna 16 mission. Lead was found to be distinctly radiogenic, but significantly less radiogenic than other lunar soils. The Th/U ratio was found to be 3.8, and the uranium concentration was the lowest so far found for lunar soils.

Tera, F.↗
NASA NTRS1972

Extraction of an urease-active organo-complex from soil.

Description of an extraction from a Dublin clay loam soil of a colloidal organic matter complex that is urease active and, by X-ray analysis, free of clays. Urease activity in the clay-free precipitates, as in the soil, was not destroyed by the activity of an added proteolytic enzyme, pronase. This is attributed to the circumstance that native soil urease resides in organic colloidal particles with pores large enough for water, urea, ammonia, and carbon dioxide to pass freely, but nevertheless small enough to exclude pronase.

Burns, R. G.↗
NASA NTRS1972

Soil mechanics

Preliminary results are presented of an investigation of the physical and mechanical properties of lunar soil on the Descartes slopes, and the Cayley Plains in the vicinity of the LM for Apollo 16. The soil mechanics data were derived form (1) crew commentary and debriefings, (2) television, (3) lunar surface photography, (4) performance data and observations of interactions between soil and lunar roving vehicle, (5) drive-tube and deep drill samples, (6) sample characteristics, and (7) measurements using the SRP. The general characteristics, stratigraphy and variability are described along with the core samples, penetrometer test results, density, porosity and strength.

Mitchell, J. K.↗
NASA NTRS1973

Remote monitoring of soil moisture using airborne microwave radiometers

The current status of microwave radiometry is provided. The fundamentals of the microwave radiometer are reviewed with particular reference to airborne operations, and the interpretative procedures normally used for the modeling of the apparent temperature are presented. Airborne microwave radiometer measurements were made over selected flight lines in Chickasha, Oklahoma and Weslaco, Texas. Extensive ground measurements of soil moisture were made in support of the aircraft mission over the two locations. In addition, laboratory determination of the complex permittivities of soil samples taken from the flight lines were made with varying moisture contents. The data were analyzed to determine the degree of correlation between measured apparent temperatures and soil moisture content.

Kroll, C. L.↗
NASA NTRS1973

Ionic migration and weathering in frozen Antarctic soils

Soils of continental Antarctica are forming in one of the most severe terrestrial environments. Continuously low temperatures and the scarcity of water in the liquid state result in the development of desert-type soils. In an earlier experiment to determine the degree to which radioactive Na(Cl-36) would migrate from a shallow point source in permafrost, movement was observed. To confirm this result, a similar experiment involving (Na-22)Cl was conducted. Significantly less movement of the Na-22 ion was observed. Ionic movement in the unfrozen interfacial films at mineral surfaces in frozen ground is held to be important in chemical weathering in Antarctic soils.

Ugolini, F. C.↗
NASA NTRS1968

Soil penetrometer

An auger-type soil penetrometer for burrowing into soil formations is described. The auger, while initially moving along a predetermined path, may deviate from the path when encountering an obstruction in the soil. Alterations and modifications may be made in the structure so that it may be used for other purposes.

Howard, E. A.↗
NASA NTRS1972

Noritic fragments in the Apollo 14 and 12 soils and the origin of Oceanus Procellarum.

Fragments of noritic breccias having a range of recrystallization textures and noritic basalts comprise about 80% of the 1 to 2 mm soil samples from Cone Crater (14142) and the bottom of the trench (14151). In five other samples, noritic fragments range in abundance from 42 to 56%. The remaining particles in each case are glasses, soil breccias, and glass-bonded aggregates; other crystalline rock types such as anorthosites constitute less than 1% of the soil. Noritic materials - i.e., Apollo 12 and 14 norites and ropy (KREEP) glass particles, can be divided into two broad groups on a chemical basis. The particles in one group have relatively high bulk TiO2 contents and high Fe/(Fe + Mg) ratios in their normative pyroxenes; the ropy glasses from Apollo 12 and 14 and a few Apollo 12 noritic rock fragments are in this category. Particles in the other class contain pyroxenes with a lower Fe/(Fe + Mg) and have a range of TiO2 contents; most noritic rock fragments from Apollo 12 and 14 are in this group. The ropy glasses may be from Copernicus or other rayed craters, but almost all the norites derive from the Fra Mauro formation or other noritic occurrences associated with Oceanus Procellarum.

Taylor, G. J.↗
NASA NTRS1972

Radiation effects in soils from five lunar missions.

Optical and high-voltage electron microscopy were used to study radiation-produced defects. There is no systematic decrease in solar flare track distributions in lunar fines even to a depth of 2.5 m. The soil gradually accumulates in thickness; stirring by impacts is usually on a small scale. The accumulation rate at Luna 16 site is far lower than at the Apollo sites; the mean track density in micron-size grains there exceeds one trillion per sq cm; more than 90% of those grains are metamict; the Luna 16 site is at high longitude where electrostatic charging and transport of soil by geomagnetic tail electrons are minimal. A large fraction of soil grains on sloping ground have been isotropically irradiated, suggesting a tumbling downhill motion.-

Phakey, P. P.↗
NASA NTRS1972

Strength and compressibility of returned lunar soil.

Two oedometer and three direct shear tests have been performed in vacuum on a 200 g sample of lunar soil from Apollo 12 (12001, 119). The compressibility data have been used to calculate bulk density and shear wave velocity versus depth on the lunar surface. The shear wave velocity was found to increase approximately with the one-fourth power of the depth, and the results suggest that the Apollo 14 Active Seismic Experiment may not have detected the Fra Mauro formation at a depth of 8.5 m, but only naturally consolidated lunar soil. The shear data indicate that the strength of the lunar soil sample is about 65% that of a ground basalt simulant at the same void ratio.

Carrier, W. D., III↗
NASA NTRS1973

Luna 20 soil - Abundance and composition of phases in the 45-125 micron fraction.

Glass compositions in the Luna 20 soil indicate a minor contribution of mare rocks and a major contribution of highly feldspathic highland material. Glasses with the composition of highland basalt (anorthositic gabbro or norite) predominate in a range of highly aluminous glasses. The analyses of minerals in the soil show that the highland rocks have a unique assemblage of minerals that can readily be distinguished from the mineral assemblages of either mare or KREEP basalts. The soils are characterized by abundant anorthitic, low-Fe plagioclase. Highly magnesian orthopyroxenes, pigeonites, and augites are the most prominent pyroxenes. Unlike mare basalt pyroxenes, clinopyroxenes with intermediate Ca values are not abundant, but extreme iron enrichment toward pyroxferroite does occur. Olivines are more abundant than at other sites and are Mg-rich, low in Ca and Cr. Spinels with compositions approaching MgAl2O4 predominate over pleonastes and chromites. Ilmenite and metal are present but not abundant. The mineral compositions are consistent with derivation from a suite of highly feldspathic rocks in which highland basalt compositions predominate.

Reid, A. M.↗
NASA NTRS1973

Lunar volcanism - Age of the glass in the Apollo 17 orange soil.

Glasses on the moon can form either by impact or by volcanic processes. An age determination indicates that the glass of the orange soil formed close in time to the volcanic activity in the Sea of Serenity about 3,750 million years ago. The orange soil was certainly not formed by a recent fumarole. The young exposure age, about 32 million years, found for the glass of the orange soil is in agreement with its fresh appearance on the lunar surface.

Husain, L.↗
NASA NTRS1973

Extralunar materials in cone-crater soil 14141.

Radiochemical neutron activation analysis has been used to determine Ni, Zn, Ga, Ge, Cd, In, Ir, and Au in duplicate samples of lunar soil 14141 and in one additional replicate each of soils 14163 and 14259. The concentrations of extralunar trace elements Ni, Ge, Ir, and Au in 14141 and 14163 are, respectively, about 69 and 82% as high as those in 14259. Although most of the mass of 14141 appears to be ejecta from Cone Crater, a sizable contamination by mature Fra Mauro soil such as 14259 is also present. The siderophilic-element concentrations of the subregolith Fra Mauro materials are estimated to be 25 plus or minus 25% of those observed in 14259.

Wasson, J. T.↗
NASA NTRS1973

Soil mechanics

The soil mechanics experiment on the Apollo 17 mission to the Taurus-Littrow area of the moon is discussed. The objectives of the experiment were to determine the physical characteristics and mechanical properties of the lunar soil at the surface and subsurface in lateral directions. Data obtained on the lunar surface in conjunction with observations of returned samples of lunar soil are used to determine in-place density and porosity profiles and to determine strength characteristics on local and regional scales.

Mitchell, J. K.↗
NASA NTRS1974

Predicting soil moisture and wheat vegetative growth from ERTS-1 imagery

The author has identified the following significant results. Study results indicate: (1) Vegetative growth was best predicted by a linear relationship between leaf area index and the radio of band 4 to band 5. All significant soil moisture effects were cancelled by the ratio. (2) Soil moisture at a depth of 0 to 15 cm, with specific soil factors, was predicted by band 4 and leaf area index with a high regression coefficient. (3) Vegetative growth, measured by leaf area index, was one of the necessary inputs in evaluating the winter wheat crop coefficient from March to maturity.

Krupp, J. W.↗
NASA NTRS1973

In situ detection of microbial respiration in soils and salt flats

Increase in CO2 partial pressures over a desert soil treated with casamino-acids glucose solution correlated with bacterial growth. Few or no increases in numbers of bacteria or CO2 concentrations were noted in similar plots treated with water only or receiving no treatment. Growth in the soil appeared to be severely nutrient limited during the 10 day experiment. Especially rapid growth took place between the third and fifth day, when temperatures ranged from 0 deg. (night) to a maximum of 17.4 deg. (day). Under the conditions of the experiment, intermittent CO2 assay was an insensitive indicator of growth, possibly because of restiction of gas escape by the desert pavement or solution, exchange, or precipitation of carbonate, but more likely because of inefficient sealing of hoods to and below the soil surface. CO2 assay was unable to detect microbial successions. The unpredictable course of these successions, plus unpredictable relative retentions mitigates against assay of organic gases as reliable in situ detection of microbial activity, except perhaps in very alkaline environments such as Owens Lake salts.

Tew, R. W.↗
NASA NTRS1973

Lunar soil grain size distribution

A comprehensive review has been made of the currently available data for lunar grain size distributions. It has been concluded that there is little or no statistical difference among the large majority of the soil samples from the Apollo 11, 12, 14, and 15 missions. The grain size distribution for these soils has reached a steady state in which the comminution processes are balanced by the aggregation processes. The median particle size for the steady-state soil is 40 to 130 microns. The predictions of lunar grain size distributions based on the Surveyor television photographs have been found to be quantitatively in error and qualitatively misleading.

Carrier, W. D., III↗
NASA NTRS1973

Lipid composition of slash pine tissue cultures grown with lunar and earth soils

Lipid analyses were conducted on slash pine tissues grown in culture in the presence of lunar (Apollo 15) and earth soils. Significant reductions in the total lipids, fatty acids, and sterol components were found in the tissues grown in contact with each of the soils employed when compared to the control. Tissues grown with lunar soil showed the greatest reductions. These results are discussed with respect to previous ultrastructural studies on similarly treated slash pine tissues and lipid analyses on tobacco tissue cultures.

Laseter, J. L.↗