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Chinese Academy of Sciences Institutional Repositories Grid
The formation mechanism of 4179 Toutatis' elongated bilobed structure in a close Earth encounter scenario

文献类型:期刊论文

作者Hu, Shoucun1,2; Ji, Jianghui1; Richardson, Derek C.3; Zhao, Yuhui1; Zhang, Yun4
刊名MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
出版日期2018-07-01
卷号478期号:1页码:501-515
ISSN号0035-8711
关键词methods: numerical minor planets, asteroids: individual: 4179 Toutatis planets and satellites: formation
DOI10.1093/mnras/sty1073
通讯作者Ji, Jianghui(jijh@pmo.ac.cn)
英文摘要The optical images of near-Earth asteroid 4179 Toutatis acquired by Chang'e-2 spacecraft show that Toutatis has an elongated contact binary configuration, with the contact point located along the long axis. We speculate that such configuration may have resulted from a low-speed impact between two components. In this work, we performed a series of numerical simulations and compared the results with the optical images, to examine the mechanism and better understand the formation of Toutatis. Herein, we propose a scenario that an assumed separated binary precursor could undergo a close encounter with Earth, leading to an impact between the primary and secondary, and the elongation is caused by Earth's tide. The precursor is assumed to be a doubly synchronous binary with a semimajor axis of 4R(p) (radius of primary) and the two components are represented as spherical cohesionless self-gravitating granular aggregates. The mutual orbits are simulated in a Monte Carlo routine to provide appropriate parameters for our N-body simulations of impact and tidal distortion. We employ the PK DG RAV package with a soft-sphere discrete element method to explore the entire scenarios. The results show that contact binary configurations are natural outcomes under this scenario, whereas the shape of the primary is almost not affected by the impact of the secondary. However, our simulations further provide an elongated contact binary configuration best matching to the shape of Toutatis at an approaching distance r(p) = 1.4-1.5 R-e (Earth radius), indicative of a likely formation scenario for configurations of Toutatis-like elongated contact binaries.
WOS关键词BINARY ASTEROIDS ; 99942 APOPHIS ; GRAVITATIONAL ENCOUNTERS ; DYNAMICAL EVOLUTION ; RADAR OBSERVATIONS ; CONTACT BINARY ; SPIN-STATE ; MODEL ; CHANGE-2 ; IMAGES
WOS研究方向Astronomy & Astrophysics
语种英语
出版者OXFORD UNIV PRESS
WOS记录号WOS:000439501300037
源URL[http://libir.pmo.ac.cn/handle/332002/21567]  
专题中国科学院紫金山天文台
通讯作者Ji, Jianghui
作者单位1.Chinese Acad Sci, Purple Mt Observ, CAS Key Lab Planetary Sci, Nanjing 210008, Jiangsu, Peoples R China
2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
3.Univ Maryland, Dept Astron, College Pk, MD 20740 USA
4.Tsinghua Univ, Sch Aerosp Engn, Beijing 100084, Peoples R China
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Hu, Shoucun,Ji, Jianghui,Richardson, Derek C.,et al. The formation mechanism of 4179 Toutatis' elongated bilobed structure in a close Earth encounter scenario[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2018,478(1):501-515.
APA Hu, Shoucun,Ji, Jianghui,Richardson, Derek C.,Zhao, Yuhui,&Zhang, Yun.(2018).The formation mechanism of 4179 Toutatis' elongated bilobed structure in a close Earth encounter scenario.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,478(1),501-515.
MLA Hu, Shoucun,et al."The formation mechanism of 4179 Toutatis' elongated bilobed structure in a close Earth encounter scenario".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 478.1(2018):501-515.

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