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Structure and density of cometary nuclei

Weissman, P. R. and Asphaug, E. and Lowry, S. C. (2004) Structure and density of cometary nuclei. In: Festou, Michel and Keller, H. Uwe and Weaver, Harold A., eds. Comets II. Space Science Series . The University of Arizona Press, Tucson, USA, pp. 337-357. ISBN 978-0-8165-2450-1. (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
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http://www.uapress.arizona.edu/Books/bid1580.htm

Abstract

We are still at a very primitive stage in our understanding of the structure and density of cometary nuclei. Much of the evidence at our disposal is fragmentary and often indirect. Never- theless, a compelling picture is beginning to emerge of cometary nuclei as collisionally processed fractal aggregates, i.e., rubble piles. The evidence comes from observations of split and disrupted comets, in particular Shoemaker-Levy 9, from theories of planetesimal formation in the early solar nebula, from a recognition of the role of collisions in the evolution of cometary nuclei, and from theoretical and experimental studies of the fragmentation and reassembly of asteroids. This paradigm-shift away from nuclei as monolithic bodies parallels that which has occurred for aster- oids in the past decade. A related factor that strongly suggests that nuclei contain substantial macroscopic voids is estimates of the nuclear density, which, like asteroids, show comets to be “under-dense” compared with their constituent materials. We find that the bulk density of com- etary nuclei lies in the range 0.5–1.2 g cm–3, with a perhaps “best” current value of 0.6 g cm–3.

Item Type: Book section
Subjects: Q Science > QB Astronomy
Divisions: Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Stephen Lowry
Date Deposited: 08 Dec 2015 22:34 UTC
Last Modified: 29 May 2019 16:40 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/52934 (The current URI for this page, for reference purposes)
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