NOAO > Library > NOAO Preprint Series > Preprint 890
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NOAO > Library > NOAO Preprint Series > Preprint 890 |
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Author(s): Samarasinha, N.H.
Title: A Model for the Breakup of Comet
Linear
(C/1999 S4)
Abstract:
We propose a mechanism based on the rubble-pile hypothesis of cometary nucleus
(Weissman 1986) to explain the catastrophic breakup of LINEAR (C/1999 S4)
observed during July-August 2001. We suggest that a solid nucleus made up of
10-100m "cometesimals" (Weidenschilling 1997) contains a network of
inter-connected voids in the inter-cometesimal regions. The production of
super-volatile (i.e., species more volatile than water) gasses into these
voids
occurs due to the thermal wave propogating through the nucleus and associated
phase transitions of water ice. The network of voids provides an efficient
pathway for rapid propogation of these gasses with the nucleus resulting in
gas
pressure caused stresses over a wide regime of the nucleus. This provides
a mechanism for catastrophic breakups of small cometary outbursts including
those that occur at large heliocentric distances (e.g., West et al.
1991). We emphasize the importance of techniques such as radar reflection
tomography and radiowave transmission tomography (e.g., Kofman et al.
1998) aboard cometary missions to determine the three dimensional structure
of the nucleus in particular the extent of large scale voids.
Date Received:
June 29, 2001
Publication Info:
Icarus 154:540-544
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NOAO > Library > NOAO Preprint Series > Preprint 890 |
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