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Laboratory Simulation of Cometary Structures

Published online by Cambridge University Press:  12 April 2016

KH.I. Ibadinov
Affiliation:
Institute of Astrophysics of the Tadjik Academy of Science, 734670, Dushanbe, USSR
A.A. Rahmonov
Affiliation:
Institute of Astrophysics of the Tadjik Academy of Science, 734670, Dushanbe, USSR
A.SH. Bjasso
Affiliation:
Institute of Astrophysics of the Tadjik Academy of Science, 734670, Dushanbe, USSR

Abstract

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The properties of a porous mineral crust on the surface of an icy cometary nucleus and the crust's influence on the thermal regime and gas production in the nucleus have been studied by laboratory simulation experiments. A nucleus model of H2O ice with the impurity of graphite particles has been shown to display the same temperature and surface albedo as those determined for Comet Halley’s nucleus by the VEGA 1, VEGA 2, and Giotto spacecraft. The effective thermal conductivity of a crust with a density of 0.5 × 102 kg m−3 to 0.7 × 102 kg m−3 is less than 10−1 W m−1 K−1, while the crust’s strength (103 to 104 Pa) is not sufficient to withstand its erosion by the sublimating gases. A crust that is 1 cm thick lowers the gas production of the nucleus model by one order of magnitude. The destruction of the crust, and the gas and dust production of Comet Halley’s nucleus can be explained either by a spotty surface on the nucleus or, more likely, by the presence of volatile impurities such as CO2 with concentrations of 1 × 10−2 to 3 × 10−2 in the H2O ice under the crust.

Type
Section II: Laboratory Studies and Simulations
Copyright
Copyright © Kluwer 1991

References

Combes, M., et al. (1986). “Infrared sounding of comet Halley from VEGA I,” Nature, 321, 266268.CrossRefGoogle Scholar
Dobrovolsky, O.V., and Ibadinov, K.I. (1971). “Destruction of dust matrix on comet nucleus surface,Dokladi Akademii Nauk Tadjik SSR, 14, 1619.Google Scholar
Dobrovolsky, O.V., and Kajmakov, E.A. (1977). “Surface phenomena in simulated cometary nuclei,” in Delsemme, A.H. (ed.), Comets, Asteroids, Meteorites, The University of Toledo, Toledo, Ohio, 3746.Google Scholar
Dobrovolsky, O.V., et al. (1984). “Secular brightness decrease and nuclei structure of periodical comets,Dokladi Akademii Nauk Tadjik SSR, 27, 198200.Google Scholar
Dobrovolsky, O.V., et al. (1986). “Thermal regime and surface of periodic comet nuclei,” in Battrick, B., Rolfe, E.J., and Reinhard, R. (eds.), Exploration of Halley’s Comet, Proceedings of the International Symposium held in Heidelberg, Germany, 27-31 October 1986, ESA SP-250, Vol. II, Noordwijk, The Netherlands, 389394.Google Scholar
Emerich, C., et al. (1986). “Temperature and size of the nucleus of Halley’s comet deduced from I.K.S. infrared VEGA I measurements,” in Battrick, B., Rolfe, E.J., and Reinhard, R. (eds.), Exploration of Halley’s Comet, Proceedings of the International Symposium held in Heidelberg, Germany, 27-31 October 1986, ESA SP-250, Vol. II, Noordwijk, The Netherlands, 381384.Google Scholar
Fanale, F.P., and Salvali, J.R. (1984). “An idealized short-period comet model: Surface insolation, H2O flux, dust flux, and mantle evolution,Icarus, 60, 476511.Google Scholar
Grün, E., et al. (1987). “Simulation of cometary nuclei,” in Rolfe, E.J. and Battrick, B. (eds.), Diversity and Similarity of Comets, Proceedings of an International Symposium held in Brussels, Belgium, 6-9 April 1987, ESA SP-278, Noordwijk, The Netherlands, 501508.Google Scholar
Ibadinov, K.I. (1982). “The durability of dust formed under the dusty ice sublimation,” Komety i Meteory, 34, 1923.Google Scholar
Ibadinov, K.I. (1989). “Laboratory investigations of the sublimation of comet nucleus models,Adv. Space Res., 9 (3), 97-112.Google Scholar
Ibadinov, K.I., and Aliev, S. (1984). “Laboratory investigation of the comet H2O, CO2 and NH3 ice conglomerates,Komety i Meteory, 36, 3537.Google Scholar
Ibadinov, K.I., and Aliev, S. (1987). “Sublimation characteristics of H2O comet nucleus with CO2 impurities,” in Rolfe, E.J. and Battrick, B. (eds.), Diversity and Similarity of Comets, Proceedings of an International Symposium held in Brussels, Belgium, 6-9 April 1987, ESA SP-278, Noordwijk, The Netherlands, 717719.Google Scholar
Ibadinov, K.I., and Kajmakov, E.A. (1970). “Formation and destruction of dust matrices during sublimation of dusty ice,Komety i Meteory, 19, 2024.Google Scholar
Ibadinov, K.I., and Rahmonov, A.A. (1988). “Laboratory simulation layer on comet Halley nucleus surface,Kometny Circ., 395, 4 Google Scholar
Ibadinov, K.I., et al. (1985). “The formation rate and physical+mechanical characteristics of organic matrixes on the surface comet nuclei models,Dokladi Akademii Nauk Tadjik SSR, 28, 2124.Google Scholar
Ibadinov, K.I., et al. (1987a). “Physical-mechanical properties of matrixes on the comet nuclei surface model,” in Rolfe, E.J. and Battrick, B. (eds.), Diversity and Similarity of Comets, Proceedings of an International Symposium held in Brussels, Belgium, 6-9 April 1987, ESA SP-278, Noordwijk, The Netherlands, 713716.Google Scholar
Ibadinov, K.I., et al. (1987b). “Laboratory investigation of thermal conductivity of dust models on the ice comet nuclei surfaces,” in Ceplecha, Z. and Pecina, P. (eds.), Interplanetary Matter, Proceedings of the 10th European Regional Astronomy Meeting of the IAU, 24-29 August 1987, Praha, Czechoslovakia, 2, 5557.Google Scholar
Kajmakov, E.A., and Ibadinov, K.I. (1971). “Influence of light on dusty ices,Komety i Meteory, 20, 913.Google Scholar
Klinger, J., et al. (1989). “How far do results of recent simulation experiments fit current models of cometary nuclei,” in Proceedings of the 19th Lunar and Planetary Science Conference, Lunar and Planetary Institute, Houston, 493497.Google Scholar
Kochan, H., et al. (1989). “Laboratory simulation of a cometary nucleus: Experimental setup and first results,” in Proceedings of the 19th Lunar and Planetary Science Conference, Lunar and Planetary Institute, Houston, 487492.Google Scholar
Lizunkova, I.S., et al. (1977). “Simulation of cometary dust particles,Sov. Astron. J., Letter 3, 518521.Google Scholar
Markovich, M.Z. (1958). “Thermal conductivity of cometary nucleus surface layer,” Bulleten Instituta Astrofiziki Akademii Nauk Tadjik SSR, 3-14.Google Scholar
Markovich, M.Z. (1961). “Nuclei temperature of comets with great aphelion distances,” Bulleten Komissii po Kometam i Meteoram, 6, 2531.Google Scholar
Markovich, M.Z. (1986). “On the theory of the ‘spotty’ model of cometary nucleus,Kinematika i Fizika Nebesnykh Tel, 2, 7076.Google Scholar
Matveev, N.N., and Kajmakov, E.A. (1980). “Experimental research of the probable parent Na- and Li-containing molecules in comet,Komety i Meteory, 28, 1725.Google Scholar
Mendis, D.A., and Brin, G.O. (1977). “Monochromatic brightness variations of comets.II. Core-mantle model,Moon, 17, 359372.CrossRefGoogle Scholar
Reinhard, R. (1986). “The Giotto encounter with comet Halley,Nature, 321 (6067), 313318.Google Scholar
Riives, V.G. (1966). “Intensity of gas production in comets,Komety i Meteory, 13, 38.Google Scholar
Sagdeev, R.Z., et al. (1986). “VEGA spacecraft encounters with comet Halley,Nature, 321 (6067), 259262.Google Scholar
Sekanina, Z., and Larson, S.M. (1986). “Coma morphology and dust emission pattern of Periodic Comet Halley. N. Spin vector refinement and map of discrete dust sources for 1910,Astron. J., 92, 462482.Google Scholar
Shul’man, L.M. (1972). Dinamika kometnyh atmospher. Nejtralnyj gas, Naukova Dumka, Kiev.Google Scholar
Shul’man, L.M. (1987). Jadra komet, Nauka, Moscow.Google Scholar
Whipple, F.L. (1950). “A comet model. I. The acceleration of comet Encke,Astrophys. J., 111, 375394.Google Scholar
Whipple, F.L. (1951). “A comet model. II. Physical relations for comets and meteors,Astrophys. J., 113, 464474.Google Scholar
Yeomans, D.K. (1986). “The comet Halley ephemeris development effort,” in Reinhard, R. and Battrick, B. (eds.), Space Missions to Halley’s Comet, ESA SP-1066, Noordwijk, The Netherlands, 179198.Google Scholar