Crystallization, sublimation, and gas release in the interior of a porous comet nucleus
1992; IOP Publishing; Volume: 388; Linguagem: Inglês
10.1086/171143
ISSN1538-4357
Autores Tópico(s)Space Exploration and Technology
Resumoview Abstract Citations (95) References (26) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Crystallization, Sublimation, and Gas Release in the Interior of a Porous Comet Nucleus Prialnik, Dina Abstract A numerical code is developed for evolutionary calculations of the thermal structure and composition of a porous comet nucleus made of water ice, in amorphous or crystalline form, other volatiles, dust, and gases trapped in amorphous ice. Bulk evaporation, crystallization, gas release, and free (Knudsen) flow of gases through the pores are taken into account. The numerical scheme yields exact conservation laws for mass and energy. The code is used to study the effect of bulk evaporation of ice in the interior of a comet nucleus during crystallization. It is found that evaporation controls the temperature distribution; the vapor prevents cooling of the crystallized layer of ice, by recondensation and release of latent heat. Thus high temperatures are maintained below the surface of the nucleus and down to depths of tens or hundreds of meters, even at large heliocentric distances, as long as crystallization goes on. Gas trapped in the ice and released during the phase transition flows both toward the interior and toward the surface and out of the nucleus. The progress of crystallization is largely determined by the contribution of gas fluxes to heat transfer. Publication: The Astrophysical Journal Pub Date: March 1992 DOI: 10.1086/171143 Bibcode: 1992ApJ...388..196P Keywords: Comet Nuclei; Crystallization; Sublimation; Cosmic Dust; Heat Transfer; Ice; Porosity; Water; Astrophysics; COMETS: GENERAL full text sources ADS |
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