elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Contact | Deutsch
Fontsize: [-] Text [+]

New Thermal Model of the Sub-Surface Layer of Comets

Gortsas, Nikolaos and Kührt, Ekkehard and Motschmann, Uwe and Keller, Horst Uwe (2007) New Thermal Model of the Sub-Surface Layer of Comets. In: Bulletin of the American Astronomical Society, DPS meeting 39, 43.07, 39 (3), pp. 498-499. American Astronomical Society. American Astronomical Society, DPS meeting 39, 2007-10-7 - 2007-10-12, Orlando, Florida (USA). ISSN 0002-7537

Full text not available from this repository.

Abstract

Thermal modeling is an essential tool for investigations of cometary activity and other typical cometary phenomena. Various thermal models have been published to date but their usefulness is compromised by lack of knowledge of the thermal properties of cometary matter. However, recent ground-based measurements of Hale-Bopp (Kührt, 2002) and space-based observations of 9P/Tempel 1 with the Deep Impact spacecraft (Groussin et al., 2007) provide crucial constraints on the physical properties of the nuclei. It is now clear that the heat conductivity of cometary matter is extremely low. Analytical results based on a simplified model lead to the hypothesis that under these circumstances, near perihelion, a thermal wave penetrates the surface material with an average speed lower than that of surface erosion. This effect, together with the low thermal skin depth, implies that subsurface layers are considerably less heated than indicated by previous models. Consequently, water ice sublimation should be confined to the surface and immediate sub-surface layers. In order to quantify this hypothesis we have developed and tested a novel thermal conduction code which allows the strongly nonlinear heat conduction equation and the erosion to be treated consistently by means of a moving surface boundary condition, the so called Stefan problem. A crucial aspect of our method is the numerical treatment of energy conservation. First results of our numerical computations are presented. O. Groussin et al., Surface temperature of the nucleus of Comet 9P/Tempel 1, Icarus 187, 16-25, 2007 E. Kührt, From Hale-Bopp's Activity to Properties of its Nucleus, Earth, Moon and Planets 90, 1-4 / June, 2002

Document Type:Conference or Workshop Item (Speech)
Title:New Thermal Model of the Sub-Surface Layer of Comets
Authors:
AuthorsInstitution or Email of Authors
Gortsas, NikolaosUNSPECIFIED
Kührt, EkkehardUNSPECIFIED
Motschmann, UweDLR und TU Braunschweig
Keller, Horst UweMax-Planck-Institut für Sonnensystemforschung
Date:October 2007
Journal or Publication Title:Bulletin of the American Astronomical Society, DPS meeting 39, 43.07
Refereed publication:No
In SCOPUS:No
In ISI Web of Science:No
Volume:39
Page Range:pp. 498-499
Editors:
EditorsEmail
American Astronomical Society, UNSPECIFIED
Publisher:American Astronomical Society
Series Name:Bulletin of the American Astronomical Society
ISSN:0002-7537
Status:Published
Keywords:Comets, Activity, Thermal modeling, Simulation, Surface erosion, Hale-Bopp
Event Title:American Astronomical Society, DPS meeting 39
Event Location:Orlando, Florida (USA)
Event Type:international Conference
Event Dates:2007-10-7 - 2007-10-12
Organizer:American Astronomical Society
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Space (old)
HGF - Program Themes:W EW - Erforschung des Weltraums
DLR - Research area:Space
DLR - Program:W EW - Erforschung des Weltraums
DLR - Research theme (Project):W - Vorhaben Asteroiden und Kometen (old)
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Planetary Research > Asteroids and Comets
Deposited By: Nikolaos Gortsas
Deposited On:16 Mar 2009
Last Modified:27 Aug 2009 09:26

Repository Staff Only: item control page

Browse
Search
Help & Contact
Informationen
electronic library is running on EPrints 3.3.12
Copyright © 2008-2012 German Aerospace Center (DLR). All rights reserved.