Доклады Академии наукДоклады Академии наук0869-5652The Russian Academy of Sciences1171710.31857/S0869-56524842150-155Research ArticleNumerical simulation of the long-term thermal evolution of the nuclei of short-period comets:using the nucleus of comet 67p/Churyumov–Gerasimenko as an exampleMarovM. Ya.fermata@inbox.ruRusolA. V.fermata@inbox.ruDorofeevaV. A.fermata@inbox.ruVernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences1304201948421501551204201912042019Copyright © 2019, Russian Academy of Sciences2019<p>Using numerical models, we have studied what depth of the outer layer the comet nuclei are degassed to when they are in orbits whose perihelion is close to the Sun for tens of years. The problem is topical, because it helps to understand how much the experimentally obtained results on the composition of comet comas depend on how long the comet is in its present-day orbit and how adequately the data obtained reflect the composition of comet nuclei as a whole. The proposed approach, which is demonstrated using comet 67P/ChuryumovGerasimenko as an example, is based on a 3D comet nucleus surface relief model and takes into account not only its orbital motion, but also its diurnal rotation. The propagation of heat in the nucleus subsurface layers is described by a 1D heat conduction equation for a porous rock-ice composition of matter. Based on this approach, we have derived the temperature distributions in the subsurface layers for several surface patches located in the Maat region in 20 revolutions around the Sun, ~130 years.</p>cometsthermal evolution modelheat propagation depthкометымодель тепловой эволюцииглубина распространения тепла[Маров М.Я. Физические свойства и модели комет. // Астрон. вестн. 1994. Т. 28. № 4/5. С. 5–85.][Маров М.Я., Русол А.В., Дорофеева В.А. Трехмерная модель освещенности кометных ядер: на примере ядра кометы 67Р/Чурюмова–Герасименко // ДАН. 2017. Т. 474. № 1. С. 41–45.][Карпинос Д.М., Клименко В.М. Пористые конструкционные материалы и их теплофизические свойства. Киев: Знание, 1978.][Черемской П.Г. Слезов В.В., Бетехтин В.И. Поры в твердом теле. М.: Энергоатомиздат, 1990.][Hu, X., Shi X., Siers H., Blum J., Oberst J., Fulle M., Kührt E., Güttler C., Gudlach B., Keller H.U., Mottola S., Pajo-la M., Barbieri C., Lamy P.L., Rod- rigo R., Koschny D., Rickman Y., Agarwal J., AʼHern M.F., Barucci V.F., Bertaux J.-L., Bertini I., Boudreault S., Buttner I., Gremone-se G., Da Dep-po V., Davidsooon B., Debei S., De Cecco M., Del-ler J., Fornasier S., Groussin O., Gutiʹerrez-Mar-quʹes P., Hall I., Hofmann M., Hviid S.F., Ip W.-H., Jorda L., Knollenberg J., Kovaks G., Kramm J.R., Kup- pers M., Lara L.M., Lazzarin M., Lʹorez-Moreno J.J., Marzari F., Naletto G., Oklay N., Richards M.L., Ripken J., Thomas N., Tubiana C., Vincent J.-B. Thermal Modelling of Water Activity on Comet 67P/Churyumov–Gerasimenko with Global Dust Mantle and Plural Dust-to-Ice Ratio // Monthly Not. Roy. Astron. Soc. 2017.V. 469. Iss. Suppl 2. P. S295–S311.][Guilbert-Lepoutré, A., Jewitt, D. Modelling the Evolution of a Comet Subsurface: Implications for 67P/Churyumov–Gerasimenko // Monthly Not. Roy. Astron. Soc. 2016. V. 462. P. S146–S155.][Fitzsimmons, A., Snodrass C., Roziti B., Yang B., Hyland M., Seccull T., Bannister M.T., Fraser W.S., Jedicke R., Lacerda P. Spectroscopy and Thermal Modelling of the First interstellar Object 1I/2017 U1 'Oumuamua // Nature Astron. 2018. V. 2. P. 133–137.][Komle N.I., Macher W., Niefenbacher P., Karg G., Pelivan I., Knollenberg J., Jorda L., Cappana C., Lommatsch V., Cozzoni B., Finke F. Three-Dimensional Illumination and Thermal Model of the Abydos Region on Comet 67P/Churyumov–Gerasimenko // Monthly Not. Roy. Astron. Soc. 2017. V. 469. P. S2–S19.]