The lunar atmosphere and the solar wind

Bernstein, W.; Fredricks, R. W.; Vogl, J. L.; Fowler, William A.

doi:10.1016/0019-1035(63)90020-4

Cited by 23 publications

(4 citation statements)

References 21 publications

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“…The calcitic inner layer consists of crystallites parallel to the wall, whereas the aragonitic outer layer is composed of fibers radiating from the wall. This pattern has also been found in a species of Metrarabdotos Alcohol Oxidation in Rats Inhibil Pyrazole, Oximes, and Amides In 1963 Theorell and Yonetani reported that pyrazole is an inhibitor of liver alcohol dehydrogenase (ADH) in vitro (1). Pyrazole was shown to form a ternary complex with ADH and nicotinamide-adenine dinucleotide (NAD) with pyrazole occupying the ethanol binding site (2, 3).…”

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confidence: 68%

“…Therefore, we studied the effect of the formation of this complex in vivo on ethanol metabolism and observed inhibition with various amides and with pyrazole. Increased amounts of blood acetaldehyde were detected in men who had ingested ethanol after having been exposed to n-butyraldoxime (8). Koe and Tenen have found that n-butyraldoxime is a potent inhibitor of liver ADH both in vivo and in vitro and, in addition, that there is a large decrease in liver aldehyde dehydrogenase activity in mice pretreated with n-butyraldoxime, an inhibition not demonstrable in vitro (9).…”

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confidence: 99%

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Phylum Ectoprocta, Order Cheilostomata: Microprobe Analysis of Calcium, Magnesium, Strontium, and Phosphorus in Skeletons

Schöpf

Allan²

1970

Science

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Calcium, magnesium, and strontium occur in approximately constant ratios in traverses through skeletal walls of a single mineralogy (either calcite or aragonite). Skeletal walls of more than one mineralogy have the magnesium-rich layer (calcite) surrounding the living chamber and the strontium-rich layer (aragonite) on the outside. In contrast, phosphorus may be present in greater or lesser amounts in different parts of the same calcite skeletal wall. Aragonitic crystallites appear oriented roughly perpendicular to skeletal walls, whereas calcitic crystallites are parallel to skeletal walls.

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confidence: 68%

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confidence: 99%

Phylum Ectoprocta, Order Cheilostomata: Microprobe Analysis of Calcium, Magnesium, Strontium, and Phosphorus in Skeletons

Schöpf

Allan²

1970

Science

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“…Hod{Tes and Johnson [1968] and Hodges [1972] have derived the theory of exospheric transport for the heavier gases, which are expected to be distributed at the lunar surface approximately as the -5/2 power of temperature. Sources of these gases and their probable abundances have been discussed by Bernstein et al [1963], Hinton and Taeusch [1964], Johnson [1971], Siscoe and Mukherjee [1972], and Johnson et al [1972].…”

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Helium and hydrogen in the lunar atmosphere

Hodges¹

1973

J. Geophys. Res.

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Solar wind ions impinge on the surface of the moon, become neutralized, and are subsequently released to become part of the neutral lunar atmosphere. Of the gas species supplied by the solar wind, only helium and hydrogen are light enough to be lost from the moon by Jeans' thermal escape mechanism. To study the behavior of helium and hydrogen, a Monte Carlo technique has been used, in which random ballistic trajectories of individual molecules are traced over a spherical moon. In the computation, a particle is ‘created’ on the sunlit surface, and the locations of its subsequent encounters with the surface are recorded until it escapes. Global distributions of helium and hydrogen concentrations have been computed, based on the hypothesis that the release of neutral gases from the lunar surface is confined to daytime and correlated with the solar wind influx. The resulting helium model is in good agreement with the measurements from the Apollo 17 lunar surface mass spectrometer. In view of the absence of atomic hydrogen in the lunar atmosphere and the need for a loss mechanism for the solar wind influx of protons, a molecular hydrogen atmosphere model is proposed in which predicted amounts of H2 are below presently established upper bounds.

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“…The flux of photons with energy greater than l l eV is about 10 n photons/cm • s [Hinteregger, 1965] P/N --• 10 -6 ion/s atom Charge exchange. Assume an average cross section for asymmetric charge exchange of a 600-eV proton with the neutrals composing the cloud of 5 X 10 -•6 cm 2 [Bernstein et al, 1963]. The solar wind flux at the time of this event was 108 protons/cm •' s. P/N '-, 5 X 10 -8 ion/s atom Electrons.…”

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confidence: 99%

The interaction between an impact-produced neutral gas cloud and the solar wind at the lunar surface

Lindeman

Vondrak²,

Freeman

et al. 1974

J. Geophys. Res.

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On April 15, 1970, the Apollo 13 S-IVB stage impacted the nighttime lunar surface approximately 140 km west of the Apollo 12 Alsep site and 410 km west of the dawn terminator. Beginning 20 s after impact the Suprathermal Ion Detector Experiment and the Solar Wind Spectrometer observed a large flux of positive ions (maximum flux -• 3 X 108 ions/cm •' s sr) and electrons. Two separate streams of ions were observed: a horizontal flux that appeared to be deflected solar wind ions and a smaller vertical flux of predominantly heavy ions (>10 amu), which probably were material vaporized from the S-IVB stage. An examination of the data shows that collisions between neutral molecules and hot electrons (50 eV) were probably an important ionization mechanism in the impact-produced neutral gas cloud. These electrons, which were detected by the Solar Wind Spectrometer, are thought to have been energized in a shock front or some form of intense interaction region between the cloud and the solar wind. Thus strong ionization and acceleration are seen under conditions approaching a collisionless state. Both the SIDE and the SWS have been described previously [Freeman et al., 1970b, 1971b; Snyder et a/.,M970, 1971 ], but a comparison of the two instruments is helpful for an understanding of the data. This is given in Table 2. The SWS contains an array of seven Faraday cup sensors and can record charged particles arriving from all directions above the lunar surface with varying sensitivities. The cups are arranged to look radially outward, cup 7 sampling the vertical flux and the remaining cups detecting particles moving more nearly horizontally. The SIDE contains two separate detectors, the Total Ion Detector (TID) and the Mass Analyzer (MA). Each accepts positive ions in a narrow entrance cone pointed 15 ø west of vertical in the plane of the ecliptic. Any ion flux observed by either the TID or the MA would enter the vertically oriented cup (cup 7) in the SWS. The MA requires 12 s for a complete mass spectrum at each energy. Since there are six energy steps, the MA energy-mass cycle is 72 s. The cycle times for the TID and SWS are similar, but even these detectors are unable to provide detailed time variations of transient events shorter than about half a minute. One picoampere in a single cup of the SWS corresponds to a normal parallel beam flux of 2.5 X 106 ions/cm •' s or an isotropic flux over the field of view of the cup of 4.1 X 106 ions/cm •' s st. OBSERVATIONS Some SIDE data from this event have been reported previously [Freeman and Hills, 1970a; Freeman et al., 1971a]. The SWS data have been discussed by C. Snyder, D. Clay, and M. Neugebauer (unpublished data, 1971). The results of these reports and additional analysis can be summarized as follows:1. Large fluxes of ions were seen from both the horizontal and the vertical directions, the largest fluxes arriving from the

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The lunar atmosphere and the solar wind

Cited by 23 publications

References 21 publications

Phylum Ectoprocta, Order Cheilostomata: Microprobe Analysis of Calcium, Magnesium, Strontium, and Phosphorus in Skeletons

Phylum Ectoprocta, Order Cheilostomata: Microprobe Analysis of Calcium, Magnesium, Strontium, and Phosphorus in Skeletons

Helium and hydrogen in the lunar atmosphere

The interaction between an impact-produced neutral gas cloud and the solar wind at the lunar surface

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