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Composition and structure of the Venus atmosphere - Results from Pioneer VenusThe composition of the Venusian atmosphere was studied using a mass spectrometer on the Pioneer Venus sounder probe. The single-focusing magnetic-sector spectrometer scanned the mass range from hydrogen through mercury with a dynamic range of six decades. Data taken by the mass spectrometer were compared with those of a gas chromatograph, resulting in slight discrepancies due to the use of a sputter ion pump acting as a sink for entry of rare gases through the inlet leak. A surprisingly large concentration of primordial Ar-36 and Ar-38 was discovered in a ratio of 5 to 1. It was concluded that the large excess of primordial argon was a valid result and that the mixing of HCl in the lower Venusian atmosphere was less than a few parts per million. Arguments against the sun as the source for excess primordial gases on Venus were presented. Concentrations of other elements such as Ne, Kr, He, S, and O were discussed. Although the mass peaks in the spectrum were real, it was not clear whether all of the chemical reactions (i.e., COS production) actually occurred in the atmosphere. Until further analysis can be made, it will be uncertain how the inlet system, which is at atmospheric temperature, affected the results.
Document ID
19790056798
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Hoffman, J. H.
(Texas Univ. at Dallas Richardson, TX, United States)
Hodges, R. R., Jr.
(Texas, University Richardson, Tex., United States)
Mcelroy, M. B.
(Harvard University Cambridge, Mass., United States)
Donahue, T. M.
(Michigan, University Ann Arbor, Mich., United States)
Kolpin, M.
(Physics International Co. San Leandro, Calif., United States)
Date Acquired
August 9, 2013
Publication Date
July 6, 1979
Publication Information
Publication: Science
Volume: 205
Subject Category
Lunar And Planetary Exploration
Accession Number
79A40811
Funding Number(s)
CONTRACT_GRANT: NAS2-9485
CONTRACT_GRANT: NAS2-8802
Distribution Limits
Public
Copyright
Other

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