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Chemical composition measurements of the atmosphere of Jupiter with the Galileo Probe mass spectrometerThe Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for 3He/4He, D/H, 13C/12C, 20Ne/22Ne, 38Ar/36Ar and for isotopes of both Kr and Xe.
Document ID
20040120566
Document Type
Reprint (Version printed in journal)
Authors
Niemann, H. B. (NASA Goddard Space Flight Center Greenbelt MD United States)
Atreya, S. K.
Carignan, G. R.
Donahue, T. M.
Haberman, J. A.
Harpold, D. N.
Hartle, R. E.
Hunten, D. M.
Kasprzak, W. T.
Mahaffy, P. R.
Owen, T. C.
Spencer, N. W.
Date Acquired
August 22, 2013
Publication Date
January 1, 1998
Publication Information
Publication: Advances in space research : the official journal of the Committee on Space Research (COSPAR)
Volume: 21
Issue: 11
Subject Category
Meteorology and Climatology
Distribution Limits
Public
Copyright
Other
Keywords
unmanned
long duration
Flight Experiment
Galileo Project