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NASA NTRS1974

Electrical properties of lunar soil sample 15301,38

Electrical property measurements have been made on an Apollo 15 lunar soil sample in ultrahigh vacuum from room temperature to 827 C for the frequency spectrum from 100 Hz through 1 MHz. The dielectric constant, the total ac loss tangent, and the dc conductivity were measured. The dc conductivity showed no thermal hysteresis, but an irreversible (in vacuum) thermal effect was found in the dielectric loss tangent on heating above 700 C and during the subsequent cooling. This appears to be related to several effects associated with lunar glass above 700 C. The sample also showed characteristic low-frequency dispersion in the dielectric constant with increasing temperature, presumably due to Maxwell-Wagner intergranular effects. The dielectric properties may be fitted to a model involving a Cole-Cole frequency distribution that is relatively temperature-independent below 200 C and follows a Boltzmann temperature distribution with an activation energy of 2.5 eV above 200 C. The dc conductivity is fitted by an exponential temperature distribution and becomes the dominant loss above 700 C.

Olhoeft, G. R.↗
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 NTRS1971

Orthopyroxene and orthopyroxene-bearing rock fragments rich in K, REE, and P in Apollo 14 soil sample 14163.

Orthopyroxene of various compositions are reported in the less than 1 mm fines in lunar soil sample 14163. The mineral occurs as individual grains and as a major and minor constituent in lithic fragments. K is not positively correlated with REE and P in the orthopyroxene-containing igneous rock fragments studied. Although an X-ray powder pattern of the rare earth element containing calcium phosphate is that of whitlockite, it is tentatively concluded that the weak pattern observed results from an intimate admixture of a major amount of an amorphous phosphate of unknown composition with a lesser amount of crystalline whitlockite.

Fuchs, L. H.↗
NASA NTRS1982

Automatic Collection of Rock and Soil Samples

Proposed machine would sample rock or soil automatically. Mounted on a wheeled or tracked vehicle, machine positions drill for cut at any angle from horizontal to vertical, moves power head to drive drill into cut, and stores drilled core in a container. New concept may also be useful in terrestrial agricultural and geologic surveys.

Kyrias, G. M.↗
NASA NTRS1974

Phase chemistry of Apollo 14 soil sample 14259

Optical, X-ray-diffraction and electron-microprobe techniques were used to investigate 0.26 gm of Apollo 14 soil sample 14259. Major element microprobe analyses were made of 470 mineral grains and 388 glass grains. The mineral abundances in the soil are 45% plagioclase, 41% pyroxene, 7% olivine, 3% oxides, 2% K-feldspar; 1% nickel-iron, and less than 1% troilite. The glasses have a wide range of compositions but preferred values are evident and are interpreted as representative of rock types contributing to the soil at the Fra Mauro site. Eleven per cent of the glasses have compositions like those of mare basalts or mare soils and are believed to be mare-derived. Eighty-six per cent of the glasses are equivalent in composition to basalts that have higher Al, and lower Ca/Al and Fe/Mg ratios than mare basalts. The most abundant compositional type is named Fra Mauro basaltic glass and is subdivided into three related types. The other major glass type in the soil corresponds in composition to anorthositic gabbro.

Aitken, F. K.↗
NASA NTRS1979

Determination of secondary electron emission characteristics of lunar soil samples

A procedure is described for the determination of the 'apparent crossover voltage', i.e. the value of the primary (bombarding) electron energy at which an insulating sample surface changes the average sign of its charge. This apparent crossover point is characteristic of the secondary emission properties of insulating powders such as the lunar soil samples. Lunar core samples from well-defined, distinct soil layers are found to differ significantly in their secondary emission properties. This observation supports the suggestion that soil layers were deposited by an electrostatic transport process.

Gold, T.↗
NASA NTRS1992

Mass spectrometer-pyrolysis experiment for atmospheric and soil sample analysis on the surface of Mars

Results from the Viking mission will form the foundation for future in-depth investigations of atmosphere-surface interactions on Mars. The two Viking landers carried impressive instrumentation to obtain and analyze soil samples: the sites were observed by cameras, and the collector head was located on a long boom and allowed the collection of large samples at various depths. A selection of grain sizes was possible and a distribution system supplied a number of experiments with soil material. Despite stationary vehicles, a wide sampling field was reachable. The GCMS system, responsible for atmospheric as well as surface soil analysis, worked well on both landers. Atmospheric measurements resulted in the determination of the abundance of noble gases as well as of other molecular species. Isotopic composition measurements included the important ratios of C-13/C-12, N-15/N-14, and Ar-36/Ar-40. To verify these past results and to advance detailed studies of noble gas isotope ratios and minor constituents, better instrument sensitivities, higher precision, and lower background contributions are required in future Mars missions. Soil analysis during the Viking mission concentrated on organic material. Heating cycles were performed to 500 C and only water and carbon dioxide were identified. Higher pyrolysis temperatures are of primary importance to advance our understanding of the mineralogy and gas loading of surface material and atmospheric exchange.

Mauersberger, Konrad↗
NASA NTRS1999

Sampling Soil for Characterization and Site Description

The sampling scheme for soil characterization within the GLOBE program is uniquely different from the sampling methods of the other protocols. The strategy is based on an understanding of the 5 soil forming factors (parent material, climate, biota, topography, and time) at each study site, and how each of these interact to produce a soil profile with unique characteristics and unique input and control into the atmospheric, biological, and hydrological systems. Soil profile characteristics, as opposed to soil moisture and temperature, vegetative growth, and atmospheric and hydrologic conditions, change very slowly, depending on the parameter being measured, ranging from seasonally to many thousands of years. Thus, soil information, including profile description and lab analysis, is collected only one time for each profile at a site. These data serve two purposes: 1) to supplement existing spatial information about soil profile characteristics across the landscape at local, regional, and global scales, and 2) to provide specific information within a given area about the basic substrate to which elements within the other protocols are linked. Because of the intimate link between soil properties and these other environmental elements, the static soil properties at a given site are needed to accurately interpret and understand the continually changing dynamics of soil moisture and temperature, vegetation growth and phenology, atmospheric conditions, and chemistry and turbidity in surface waters. Both the spatial and specific soil information can be used for modeling purposes to assess and make predictions about global change.

Levine, Elissa↗
NASA NTRS2006

Heavy Isotope Composition of Oxygen in Zircon from Soil Sample 14163: Lunar Perspective of an Early Ocean on the Earth

Thirty oxygen analyses of a large (sub-millimetre) zircon grain from the lunar soil sample 14163 have been determined using CAMECA 1270 ion microprobe. The sample 14163 was returned form the Fra Mauro region by Apollo 14 mission. Zircon grain of 0.6-0.8 mm in size extracted from the sample was imaged using CL detector fitted to the Philips Electron Microscope in order to reveal internal structure. Oxygen isotopes have been analysed during two sessions. The first set of data was collected using the original mount where the grain was set in the resin attached to the glass slide. This resulted in the two complications: (i) standard zircon has to be analysed from the separate mount and (ii) the lunar zircon grain was rased in the holder compared to the standard. In order to investigate, if the elevated oxygen compositions observed during this session could have resulted from this difference in geometric configuration during the standard and sample analyses, the lunar zircon was extracted from the original mount, remounted with the standard chip in the new resin disk and reanalysed during the second session. All analyses made during the first session show delta O-18 values heavier than 6.0%. The second set of data has a wider spread of delta O-18 values with some values as low as 5.6%. Nevertheless, a half of observed delta O-18 values in this set is also higher than 6.0%. Slightly lighter oxygen compositions observed during the second session indicate possible dependence of measured delta O-18 values on the geometry of analysed samples. Presence of zircons with similar heavy oxygen isotope compositions on the Moon, which neither had liquid water or felic crust similar to that on the Earth nor ever developed regime similar to plate tectonics, suggests that other mechanisms can be responsible for elevated delta O-18 values in zircons. This implies that there is no support for the presence of an ocean on the surface of the early Earth and as the ocean appears to be an essential ingredient for the plate tectonics, there is no basis for belief that this mechanism was operating in the early history of the planet.

Nemchin, A. A.↗
NASA NTRS1976

Electrical properties of Apollo 17 rock and soil samples and a summary of the electrical properties of lunar material at 450 MHz frequency

The dielectric constant and the voltage absorption length was measured for four Apollo 17 soil samples (73241, 74220, 75061, 76501) and for two Apollo 17 rock samples (76315 and 79135) at 450 MHz frequency. The dielectric constant and absorption length measurements made on the lunar samples are reviewed and related to the transition element concentration in these samples. The significance of the laboratory measurements for radar observations is discussed.

Gold, T.↗
NASA NTRS1972

Shock metamorphic effects in the Luna 16 soil sample from Mare Fecunditatis.

Diverse lunar soil fragments returned from the Luna 16 mission were examined for evidence in shock metamorphism in order to evaluate the role of meteorite impact in forming the lunar regolith at a new site relatively distant from the Apollo landing sites. It was found that shock metamorphic effects, characteristic of meteorite impact and virtually identical to those observed in Apollo samples, are common in the Luna 16 fragments. Two types of shock effects are present - i.e., a deformation and partial melting features in rock and mineral fragments, and heterogeneous glasses and glassy breccias produced by shock melting. It is concluded that these shock metamorphic effects indicate that regolith formation by meteorite impact has occurred in Mare Fecunditatis and is a general process over the entire moon.

French, B. M.↗
NASA NTRS1972

Compositions and mineralogy of lithic fragments in 1-2 mm soil samples 14002,7 and 14258,33.

The compositional data obtained are combined with existing data from larger rock samples and compared with bulk analyses of soils to determine compositional ranges and dominant igneous rock types present in the regolith and breccias. Criteria are presented for the recognition of three types of igneous fragments in a limited sample of Apollo 14 material. Explanations for the differences between glass and rock compositions are discussed.

Steele, I. M.↗
NASA NTRS1993

Multiple nitrogen components in lunar soil sample 12023

Nitrogen is one of the enigmatic elements in lunar soils and breccias. The large range in (delta)N-15 values found within lunar soils was initially attributed to a secular increase in the N-15/N-14 ratio of 50 percent within the solar corona, and hence in the implanted nitrogen within the lunar regolith. However, more recent explanations have proposed a two (or many) component mixing model of solar wind nitrogen with some hypothetical non-solar components. Such components could include indigenous lunar nitrogen, nitrogen contained in interstellar grains in primitive meteorites, and magnetospheric nitrogen from the terrestrial atmosphere. To understand the makeup of multi-component mixtures it is advantageous to have carbon and noble gas data measured simultaneously, particularly in the case of lunar soils, where the solar wind is a likely fundamental contributor of nitrogen. To this end, a new nitrogen instrument was adapted to give some of the desired data in parallel. Conjoint measurements of N abundance and (delta)N-15 together with N/Ar-36 and Ar-36/Ar-38 ratios obtained during a stepped combustion of lunar soil 12023. The results are preliminary to a much more comprehensive investigation of well characterized fractions of the sample which we still have available from a previous study. Stepped combustion of a sample of 12023,7 yielded 94 ppm nitrogen with a (delta)N-15 = +22.2 percent, as well as the characteristic heavy-light-heavy pattern observed for lunar samples. The low temperature maximum was +75.1 percent at 550 C, the minimum at 800 C with (delta)N-15 = -16.7 percent and the high temperature (delta)N-15 peak is +90.6 percent at 1250 C. The major releases of nitrogen occurred between 650 C - 800 C in the form of a double peak; a third, substantial release occurred at 1150 C yielding 14.2 ppm of nitrogen coinciding with a small but recognizable drop in (delta)N-15 against a regularly increasing trend.

Brilliant, D. R.↗
NASA NTRS1972

A quest for porphyrins in lunar soil - Samples from Apollo 11, 12 and 14.

Analyses for porphyrins in the lunar samples were carried out by extracting the lunar soils as received by organic solvents followed by analytical demetallation using methanesulfonic acid after which free-base porphyrins, if present, were recovered and demonstrably recomplexed with divalent cations. Samples from Apollo 11 showed the presence of fluorescent substances attributed to exhaust from the descent engine. One sample from Apollo 12 showed pigments resembling porphyrins. The Apollo 14 results were negative.

Hodgson, G. W.↗