| DOI: | 10.1038/s41561-018-0071-2
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| 论文题名: | Continuous reorientation of synchronous terrestrial planets due to mantle convection /704/445/862 /704/445/210 /129 article |
| 作者: | Leconte J.
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| 刊名: | Nature Geoscience
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| ISSN: | 17520894
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| 出版年: | 2018
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| 卷: | 11, 期:3 | | 起始页码: | 168
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| 结束页码: | 172
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| 语种: | 英语
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| 英文摘要: | Many known rocky exoplanets are thought to have been spun down by tidal interactions to a state of synchronous rotation, in which a planet's period of rotation is equal to that of its orbit around its host star. Investigations into atmospheric and surface processes occurring on such exoplanets thus commonly assume that day and night sides are fixed with respect to the surface over geological timescales. Here we use an analytical model to show that true polar wander - where a planetary body's spin axis shifts relative to its surface because of changes in mass distribution - can continuously reorient a synchronous rocky exoplanet. As occurs on Earth, we find that even weak mantle convection in a rocky exoplanet can produce density heterogeneities within the mantle sufficient to reorient the planet. Moreover, we show that this reorientation is made very efficient by the slower rotation rate of a synchronous planet when compared with Earth, which limits the stabilizing effect of rotational and tidal deformations. Furthermore, a relatively weak lithosphere limits its ability to support remnant loads and stabilize against reorientation. Although uncertainties exist regarding the mantle and lithospheric evolution of these worlds, we suggest that the axes of smallest and largest moment of inertia of synchronous exoplanets with active mantle convection change continuously over time, but remain closely aligned with the star-planet and orbital axes, respectively. © 2018 The Author(s). |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/105596
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| Appears in Collections: | 气候减缓与适应
科学计划与规划
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作者单位: | Laboratoire d'Astrophysique de Bordeaux, University of Bordeaux, CNRS, Pessac, France
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| Recommended Citation: | |
Leconte J.. Continuous reorientation of synchronous terrestrial planets due to mantle convection /704/445/862 /704/445/210 /129 article[J]. Nature Geoscience,2018-01-01,11(3)
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