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- Michael J. Mumma
- Head of the Planetary Systems Branch, Code 693, Goddard Space Flight Center, Greenbelt, MD 20771.
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- Harold A. Weaver
- Associate research scientist at the Center for Astrophysical Sciences, Johns Hopkins University, Baltimore, MD 21218.
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- Harold P. Larson
- Members of the Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721.
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- D. Scott Davis
- Research Associate at the Steward Observatory, University of Arizona, Tucson, AZ 85721.
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- Michael Williams
- Members of the Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721.
書誌事項
- 公開日
- 1986-06-20
- DOI
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- 10.1126/science.232.4757.1523
- 公開者
- American Association for the Advancement of Science (AAAS)
この論文をさがす
説明
<jats:p> Gaseous, neutral H <jats:sub>2</jats:sub> O was detected in the coma of comet Halley on 22.1 and 24.1 December 1985 Universal Time. Nine spectral lines of the ν <jats:sub>3</jats:sub> band (2.65 micrometers) were found by means of a Fourier transform spectrometer (λ/Δλ ∼10 <jats:sup>5</jats:sup> ) on the NASA-Kuiper Airborne Observatory. The water production rate was ∼6 × 10 <jats:sup>28</jats:sup> molecules per second on 22.1 December and 1.7 × 10 <jats:sup>29</jats:sup> molecules per second on 24.1 December UT. The numbers of spectral lines and their intensities are in accord with nonthermal-equilibrium cometary models. Rotational populations are derived from the observed spectral line intensities and excitation conditions are discussed. The ortho-para ratio was found to be 2.66 ± 0.13, corresponding to a nuclear-spin temperature of 32 K (+5 K, -2 K), possibly indicating that the observed water vapor originated from a low-temperature ice. </jats:p>
収録刊行物
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- Science
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Science 232 (4757), 1523-1528, 1986-06-20
American Association for the Advancement of Science (AAAS)
