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The chemistry of cometsComets appear to represent a population of rather homogeneous objects. In particular, the original size distribution peaks at a mean diameter of the order of 10 km. Cometary dust grains appear to be made of clusters of extremely fine particles (0.1-1.0 micron) sintered by heat at a variable degree during their perihelion passages. The brightness laws of comets appear to be derived only by the sublimation of water ice or at least of gas hydrates of the clathrate type. Pristine nuclei are likely to be radially undifferentiated; only their crustal surface must be outgassed and sintered by the heat of perihelion passages. Comet Halley is confirmed to be in the same general class as the bright comets of the 1970s. With an organic fraction of 33 percent in the cometary dust, the carbon of Comet Halley is close to cosmic abundances.
Document ID
19890049442
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Delsemme, A. H.
(Toledo, University OH, United States)
Date Acquired
August 14, 2013
Publication Date
July 29, 1988
Publication Information
Publication: Philosophical Transactions, Series A
Volume: 325
Issue: 1587
ISSN: 0080-4614
Subject Category
Astrophysics
Accession Number
89A36813
Funding Number(s)
CONTRACT_GRANT: NSF AST-86-11734
Distribution Limits
Public
Copyright
Other

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