Boreskov

OP‐6processes. Mentioned above astrophysical objects are usually rich in both gas‐phasemolecules and icy mantles of molecules atop dust particles. Both the dust particles and theiricy mantles are major reservoirs for heavy elements and their surfaces are believed tosupport catalytically the formation of complex molecules. To investigate numerically theastrochemical systems of the complex molecule formation it is necessary to use both themacroscopic methods of chemical kinetics and consideration of chemical reactions on themolecular level of description. In the latter case one of the most efficient methods is astochastic approach to the description of physical and chemical processes in the rarefiedmedia (Marov et al., 1996). In the frames of this approach the kinetic Monte Carlo methodwas developed to investigate the gas‐phase chemistry, catalytic diffusive chemical reactionson the surfaces of the interstellar dust grains and chemical exchange between solid and gasfractions of the interstellar medium (Stantcheva et al., 2002; Herbst and Shematovich, 2003;Shematovich et al., 2005; Shematovich, 2008). The investigation of the chemical pathways ofwater, formaldehyde, and methanol formation on the icy surfaces of interstellar dust grainsin the starless and protostellar cores of the dense and cold molecular clouds was animportant application of the developed approach (Stantcheva et al., 2002; Herbst andShematovich, 2003). Another interesting application of the stochastic approach is theinvestigation of the chemical exchange between icy surface of the Jovian satellite Europaand its rarefied atmosphere formed due to the sputtering of the icy surface by the highenergymagnetospheric ions (Shematovich et al., 2005; Shematovich, 2008). Theoreticalprediction of the composition and chemical evolution of the atmosphere‐icy surfaceinterface is important for the estimates of the biological potential of this Jovian satellite.[1]. This work was supported by the Russian Foundation for Basic Research (Project no. 11‐02‐00479a), andthe Federal Target Program “Academic and Teaching Staff of Innovative Russia for 2009–2013.”[2]. Herbst E., Shematovich V.I. New approaches to the modelling of surface chemistry on interstellar grains.Astro. Space Sci., 285, 725‐735, 2003.[3]. Marov M.Ya., Shematovich V.I., Bisikalo D.V. Nonequilibrium processes in the planetary and cometaryatmospheres. A kinetic approach to modelling. Space Science Reviews, 76, 1‐202, 1996.[4]. Shematovich V.I. Astrochemistry of star formation regions. In: Star Formation in the GalaxyMoscow: Yanus–K, pp. 101–118, 2006.[5]. Shematovich V.I. Ionization chemistry in H 2 O‐dominated atmospheres of icy moons. SolarSystem Research, 42, 473‐487, 2008.[6]. Shematovich, V.I., Johnson, R.E., Cooper, J. F., Wong, M.C. Surface‐bounded atmosphere ofEuropa. Icarus, 173, 480‐498, 2005.and Beyond.[7]. Stantcheva T., Shematovich V.I., Herbst E. On the master equation approach to diffusive grain‐surfacechemistry: The H, O, CO system. Astron. and Astrophys., 391, 1069‐1080, 2002.39