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Transport Characteristics of a Hierarchical Near-Surface Layer of the Nucleus of Comet 67P/Churyumov-Gerasimenko
Blum, J.; Hartogh, P.; Rezac, L. +3 more
In this paper, we develop previous studies that considered a free molecular gas flow through a dust porous mantle of a cometary nucleus. Before, we considered various types of both homogeneous and heterogeneous layers built of nonintersecting spheres, including the layers containing microscopic cracks and inner cavities. At the same time, data fro…
Transport Characteristics of the Near-Surface Layer of the Nucleus of Comet 67P/Churyumov-Gerasimenko
Blum, J.; Agarwal, J.; Rezac, L. +4 more
The paper considers the free molecular flow of gas through the dusty porous surface layer of a comet nucleus. The study is based on computer models of generation of a porous medium and Knudsen gas diffusion. We consider various types of homogeneous and heterogeneous layers constructed from nonintersecting spheres, including layers that contain mic…
Chemical and Isotope Composition of Comet 67P/Churyumov-Gerasimenko: The Rosetta-Philae Mission Results Reviewed in the Context of Cosmogony and Cosmochemistry
Dorofeeva, V. A.
The studies of the composition and structure of comet 67P/Churyumov-Gerasimenko—a short-period comet of Jupiter's family—which was an object of the recent Rosetta-Philae space mission, yielded results unique in many respects, since it was the first time that a comet was investigated in situ for a long stretch of time under varying conditions of in…
Prospects of Ground-Based and Orbital Studies of Comets and Meteors in the Post-Rosetta Mission Era
Sachkov, M. E.
In this paper, we review the current state and prospects of comet and meteor studies. Special attention is paid to scientific tasks that should be solved with a help of space missions.
Dynamics of Dust Particles of Different Structure: Application to the Modeling of Dust Motion in the Vicinity of the Nucleus of Comet 67P/Churyumov-Gerasimenko
Hartogh, P.; Rezac, L.; Lacerda, P. +2 more
We consider the estimates of the main forces acting on dust particles near a cometary nucleus. On the basis of these estimates, the motion of dust particles of different structure and mass is analyzed. We consider the following forces: (1) the cometary nucleus gravity, (2) the solar radiation pressure, and (3) the drag on dust particles by a flow …
Dynamics and Origin of Comets: New Problems Appeared after the Rosetta Space Mission
Emel'yanenko, V. V.
The data obtained in the recent Rosetta space mission to comet 67P/Churyumov-Gerasimenko have had a profound impact on the understanding of the nature of comets. In addition to revising the notions on the physical properties and structure of comets, this addresses dynamical aspects of the formation of the observed cometary populations (short- and …
Lineaments on the Surface of the Consolidated Material of the Comet 67P/Churyumov-Gerasimenko Nucleus
Keller, H. U.; Hviid, S. F.; Mall, U. +3 more
Morphologic analysis of the fragments (500 × 500 pixels) of images of comet 67P/Churyumov- Gerasimenko obtained with the OSIRIS camera for 18 regions, where the consolidated material is exposed on the surface, has been carried out. In terms of resolution, the images form a series from 0.04 to 1.29 m/pixel; consequently, the areas covered by these …
Comparison of some characteristics of comets 1P/Halley and 67P/Churyumov-Gerasimenko from the Vega and Rosetta mission data
Ksanfomality, L. V.
On March 6 and 9, 1986, for the first time in the history of science, the Russian spacecraft Vega-1 and -2 approached the nucleus of comet 1P/Halley and flew by at a small distance. A while later, on March 14, 1986, the Giotto spacecraft (European Space Agency (ESA)) followed them. Together with the Japanese spacecraft Suisei (Japan Aerospace Expl…
Estimating the strength of the nucleus material of comet 67P Churyumov-Gerasimenko
Keller, H. U.; Mottola, S.; Hviid, S. F. +5 more
Consideration is given to the estimates for the strength of the consolidated material forming the bulk of the nucleus of comet 67P Churyumov-Gerasimenko and those for the strength of the surface material overlying the consolidated material at the sites of the first and last contact of the Philae lander with the nucleus. The strength of the consoli…
From the Vega mission to comet Halley to the Rosetta mission to comet 67/P Churyumov-Gerasimenko
Zelenyi, L. M.; Ksanfomality, L. V.
The data acquired by the Vega and Giotto spacecraft, while investigating comet 1P/Halley in 1986, are compared to the results of the first phase of exploration of the nucleus of comet 67P/Churyumov-Gerasimenko performed with the Rosetta and Philae modules. The course of the Rosetta mission activity and the status of the modules after the Philae pr…