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The Forest and the Trees

Published online by Cambridge University Press:  12 April 2016

Fred L. Whipple
Fred L. Whipple*
Affiliation:
Smithsonian Astrophysical Observatory60 Garden Street Cambridge, Massachusetts 02138U.S.A.

Abstract

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Some 24 points are made concerning the author’s understanding of the cometary nucleus as developed in this colloquium. Comparisons with an earlier report are noted, and most of the earlier advances in concept are substantiated. The mean density of the Halley nucleus may have been underestimated. The dust/gas ratio apparently needs to be increased by as much as two times, perhaps to unity or higher. The nature of the rotation remains puzzling. CHON grains now appear to be more important sources of gas than thought earlier. A very low temperature at, and subsequent to, the formation of the nucleus continues to receive support, as does a solar-system composition. The 12C/i:3C ratio may, however, be lower than expected.

Type
Section VIII: Fred Whipple Reflects
Information
International Astronomical Union Colloquium , Volume 116 , Issue 2: Comets in the Post-Halley Era , 1991 , pp. 1258 - 1278
Copyright
Copyright © Kluwer 1991

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