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 |
DOI | 10.1093/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 |
推荐引用方式 GB/T 7714 | 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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来源:紫金山天文台
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