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Atmospheric sodium at the Moon was observed for altitudes from the ground up to 1800 km from 18 April to 13 May 1998, a period including an entire lunar month. Because of bad weather, coverage was incomplete but we present the analysis of 36 spectra largely from near first and third quarter phases and passage through full moon. The apparatus used was the specially built clear aperture 16.5 cm, 203 cm focal length, Mt. Lemmon Lunar Coronagraph on Mt. Lemmon in the Catalina Mountains of Tucson, Arizona. Data are interpreted in terms of Chamberlain fits to the observed emission rate using both one equivalent temperature and two source components (with both cold and hot density distributions). The extent and equivalent temperatures of the exosphere during this period trended towards an extended coma with very little fraction in the thermally accommodated regime, even near the surface. Preliminary data-model comparisons suggest that these measurements are consistent with rates and spatial distributions expected from a photonstimulated desorption source, although evidence for one, or possibly two, periods of notable meteoroid impact source might be present. A compilation of new and previously published observations illustrates an increased emission by sodium at third quarter over that of first quarter, a result that suggests that the dayside exospheric content increases, at least occasionally, following transit of the Moon through the Earth's magnetosphere. PACS Nos.: 92.60hw, 92.60Vb, 94.80+g, 95.30Dr, 95.75Fg, 95.85Kr Pendant un mois lunaire complet, entre le 18 avril et le 13 mai 1998, nous avons mesure le sodium dans l'atmosphere de la Lune, du sol jusqu'a 1800 km d'altitude. A cause de la mauvaise temperature, la couverture est incomplete, mais nous presentons l'analyse de 36 spectres surtout pres du premier et du troisieme quartier, avec des passages sur la pleine lune. L'appareil utilise etait le Coronographe Lunaire du mont Lemmon dans les montagnes Catalina pres de Tucson en Arizona. Cet appareil dedie a une pleine ouverture de 16,5 cm et une longueur focale de 203 cm. Les donnees sont interpretees par ajustement numerique de Chamberlain aux taux d'emission observes, utilisant a la fois une temperature equivalente et deux sources (avec des distributions de densite froides et chaudes). L'etendu et la temperature equivalente de l'exosphere pendant cette periode indiquaient un coma etendu avec une toute petite fraction en regime thermique, m&ne pres de la surface. Les comparaisons preliminaires entre donnees et modele suggerent que ces mesures sont coherentes avec les taux et les distributions spatiales attendus d'une source de desorption stimulee par photons, quoique il y a des indications d'une ou m&ne deux periodes de sources significatives par impact de meteorites. Une compilation de nouvelles donnees avec des resultats deja publiees illustre une augmentation de l'augmentation du sodium pendant le troisieme quartier, compare au premier quartier, ce qui suggere que le contenu de l'exosphere de jour augmente, au moins occasionnellement, apres le transit de la Lune a travers la magnetosphere de la Terre. [Traduit par la Redaction], 1. Introduction In 1998 we sought to provide more lunar atmospheric sodium measurements to better identify the relative importance of what were then considered sources of the exosphere. The observations [...]

The gamma ray spectrometer on the Mars Odyssey spacecraft measured an enhancement of atmospheric argon over southern high latitudes during autumn followed by dissipation during winter and spring. Argon does not freeze at temperatures normal for southern winter (~145 kelvin) and is left in the atmosphere, enriched relative to carbon dioxide (C[O.sub.2]), as the southern seasonal cap of C[O.sub.2] frost accumulates. Calculations of seasonal transport of argon into and out of southern high latitudes point to meridional (north-south) mixing throughout southern winter and spring., Between autumn (areocentric longitude of the Sun [L.sub.s] 0° to 90°) (1) and winter in the southern hemisphere of Mars, about 25% of the atmosphere accumulates as a thick southern [...]

Absorption spectra obtained by intracavity laser spectroscopy (ILS) often contain fringe patterns that significantly mask absorption features and hamper the quantitative analysis of ILS data. Both the parasitic etalon fringes and the fringes that originate from spatially localized losses can be suppressed by a low-amplitude audio-frequency vibration of a folding mirror in the laser cavity. Using this methodology, we show that ILS spectra recorded with multimode lasers that contain nonideal intracavity surfaces have essentially no fringe contamination. The elimination of fringe contamination improves the detection sensitivity of ILS under normal experimental conditions and thus expands the potential for ILS applications.

On 7 December 1995, the NASA Galileo probe provided in situ measurements of the helium abundance in the atmosphere of Jupiter. A Jamin interferometer measured the refractive index of the jovian atmosphere in the pressure region from 2 to 14 bars. These measurements indicate that the atmospheric helium mole fraction is 0.136 ± 0.004. The corresponding helium mass fraction is slightly below the presolar value, which suggests that separation of helium from hydrogen in Jupiter's interior is only in its early stages., In 1977, when the instruments for the Galileo probe were chosen, it was generally thought that the He abundance in the jovian atmosphere was the same as that which was [...]

ON 8 FEBRUARY 1990 THE EXTREME Ultraviolet Spectrometer (EUV) on the Galileo spacecraft obtained a spectrum of Venus in the wavelength range of 55 to 125 nm. After this encounter, [...]

Ultraviolet Spectrometer Observations of Neptune and Triton BEFORE THE VOYAGER ENCOUNTER, neither Nepture nor Triton had been detected at wavelengths shorter than 1700 [angstroms]. Measurements of the ultraviolet (UV) reflection [...]

A. L. Sprague et al. (1) attribute an enhanced emission in the potassium (K) D lines of 14 October 1987 in the equatorial region of Mercury to a diffusion source [...]

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Discusses measurements from the Galileo space probe, regarding the abundance of helium in Jupiter's atmosphere. Use of a Jamin interferometer, to measure the refractive index of the planet's atmosphere; Indications about the atmospheric helium mole fraction; Comparison of the helium mass fraction to the presolar value; What this mass fraction indicates about the separation of helium from hydrogen in the planet's interior.

Atmospheric sodium at the Moon was observed for altitudes from the ground up to 1800 km from 18 April to 13 May 1998, a period including an entire lunar month. Because of bad weather, coverage was incomplete but we present the analysis of 36 spectra largely from near first and third quarter phases and passage through full moon. The apparatus used was the specially built clear aperture 16.5 cm, 203 cm focal length, Mt. Lemmon Lunar Coronagraph on Mt. Lemmon in the Catalina Mountains of Tucson, Arizona. Data are interpreted in terms of Chamberlain fits to the observed emission rate using both one equivalent temperature and two source components (with both cold and hot density distributions). The extent and equivalent temperatures of the exosphere during this period trended towards an extended coma with very little fraction in the thermally accommodated regime, even near the surface. Preliminary data-model comparisons suggest that these measurements are consistent with rates and spatial distributions expected from a photon-stimulated desorption source, although evidence for one, or possibly two, periods of notable meteoroid impact source might be present. A compilation of new and previously published observations illustrates an increased emission by sodium at third quarter over that of first quarter, a result that suggests that the dayside exospheric content increases, at least occasionally, following transit of the Moon through the Earth's magnetosphere. [ABSTRACT FROM AUTHOR]