Modelling the evolution of a comet subsurface: implications for 67P/Churyumov–Gerasimenko
Modelling the evolution of a comet subsurface: implications for 67P/Churyumov–Gerasimenko
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模拟彗星地下演化：对 67P/Churyumov-Gerasimenko 的影响
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
S. Besse
中科院分区：
文献类型：
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作者：
A. Guilbert;E. D. Rosenberg;D. Prialnik;S. Besse
模拟彗星的演化是一项复杂的任务，旨在提供观测无法获得的物理过程和内部特性的约束，尽管它们可能为我们理解这些原始物体的起源带来关键因素。由于详细的空间和地面观测，以及对彗星核的详细实验室模拟，这一领域在乔托之后的领域取得了巨大的进步。在本文中，我们回顾了我们认为对解释ESA/罗塞塔任务对67P/ Churyumov-Gerasimenko的观测有重要意义的研究，并在需要的地方提供了新的计算方法。这些研究具有很强的统计意义，这正是这颗彗星所需要的，因为它的轨道演变数百年来都无法准确追溯到。我们发现，在67P通往太阳系内部的混沌路径上，可能发生了径向和侧向分化，而内部的不均匀性可能导致不稳定的活动模式。最后，我们讨论了在包括67P在内的几颗彗星上看到的圆形凹陷的起源，并建议它们可以被认为是过去次表层加工的证据。
Modelling the evolution of comets is a complex task aiming at providing constraints on physical processes and internal properties that are inaccessible to observations, although they could potentially bring key elements to our understanding of the origins of these primitive objects. This field has made a tremendous step forward in the post-Giotto area, owing to detailed spaceand ground-based observations, as well as detailed laboratory simulations of comet nuclei. In this paper, we review studies that we believe are significant for interpreting the observations of 67P/Churyumov–Gerasimenko by the ESA/Rosetta mission, and provide new calculations where needed. These studies hold a strong statistical significance, which is exactly what is needed for this comet with an orbital evolution that cannot be traced back accurately for more than hundreds of years. We show that radial and lateral differentiation may have occurred on 67P’s chaotic path to the inner Solar system, and that internal inhomogeneities may result in an erratic activity pattern. Finally, we discuss the origins of circular depressions seen on several comets including 67P, and suggest that they could be considered as evidence of the past processing of subsurface layers.