世亞 (行星)

世亞係一粒可能喺早期嘅太陽系入面存在嘅行星。根據大碰撞說，呢粒行星直徑大約6000公里，同火星差唔多大，喺地球同太陽嘅拉格朗日點，並喺45億3300萬年前同地球相撞而形成月球^[1]。

名

世亞係一個泰坦神，亦都係月亮神施蓮娜嘅呀媽^[2]，同世亞創造月球嘅理論符合^[3]。

軌道

根據理論，世亞嘅軌道喺地球同太陽嘅L4或L5，並且喺條軌道入面形成同火星差唔多嘅大細。

金星嘅攝動令佢同早期地球碰撞^[4]。

碰撞

根據大碰撞說，世亞環繞太陽運行嘅軌道幾乎同早期地球嘅軌道一樣，並靠近地球同太陽嘅L4或L5 ^[4]，世亞最終因為木星或金星的引力影響而撞擊地球。

通過電腦模擬，世亞以低過 4km/s 嘅速度以大約45度角撞擊地球。

原本科學家認為世亞係同地球擦撞，並同擦撞嘅碎片形成月球^[5]。噉樣假設咗正面撞擊會摧毀呢兩粒行星並喺金星同火星軌道之間形成小行星帶，之後再各自形成地球同月球^[6]^[7]。

2016年1月，有研究表明呢次撞擊係正面碰撞，而世亞嘅殘骸留咗喺地球同月球^[8]^[9]^[10]。

月球形成假說

根據現代天文學，至少有四種關於月球起源嘅假說：

一粒行星分裂成地球同月球
月球畀地球引力捕獲
地球同月球分別喺同一個原行星盤吸積入面形成
世亞撞擊早期地球，分裂出月球

根據阿波羅計劃太空員攞返來嘅月球岩石樣本證實咗佢嘅成分同地殼好似，所以好可能月球係畀某啲嘢從地球撞出嚟^[8]^[11]^[12]。

2012年，有理論認為世亞嘅核心同地幔融合，令地球核心比預期大^[13]。

2019年有證據表明世亞係喺外太陽系形成，並喺撞擊入面帶咗地球大部分水^[14]。

參考文獻

↑ "The Theia Hypothesis: New Evidence Emerges that Earth and Moon Were Once the Same". The Daily Galaxy. 2007-07-05. 原著喺2008-02-20歸檔. 喺2013-11-13搵到. {{cite web}}: Unknown parameter |dead-url= ignored (|url-status= suggested) (help)
↑ Murdin, Paul (2016). Rock Legends: The Asteroids and Their Discoverers. Springer. p. 178. Bibcode:2016rlat.book.....M. doi:10.1007/978-3-319-31836-3. ISBN 9783319318363.
↑ "Selene | Origin and meaning of selene by Online Etymology Dictionary".
↑ ^4.0 ^4.1 "STEREO Hunts for Remains of an Ancient Planet near Earth". NASA. 2009-04-09. 原著喺2013-11-13歸檔. 喺2013-11-13搵到.
↑ Reufer, Andreas; Meier, Matthias M. M.; Benz, Willy; Wieler, Rainer (2012). "A hit-and-run giant impact scenario". Icarus. 221 (1): 296–299. arXiv:1207.5224. Bibcode:2012Icar..221..296R. doi:10.1016/j.icarus.2012.07.021. S2CID 118421530.
↑ Jutzi, M.; Asphaug, E. (2011). "Forming the lunar farside highlands by accretion of a companion moon". Nature. 476 (7358): 69–72. Bibcode:2011Natur.476...69J. doi:10.1038/nature10289. PMID 21814278. S2CID 84558.
↑ "Faceoff! The Moon's oddly different sides", Astronomy, August 2014, 44–49.
↑ ^8.0 ^8.1 Nace, Trevor (2016-01-30). "New Evidence For 4.5 Billion Year Old Impact Formed Our Moon". Forbes. 喺2016-01-30搵到.
↑ Young, E. D.; Kohl, I. E.; Warren, P. H.; Rubie, D. C.; Jacobson, S. A.; Morbidelli, A. (28 January 2016). "Oxygen isotopic evidence for vigorous mixing during the Moon-forming giant impact". Science. 351 (6272): 493–496. arXiv:1603.04536. Bibcode:2016Sci...351..493Y. doi:10.1126/science.aad0525. PMID 26823426. S2CID 6548599.
↑ Wolpert, Stuart (January 28, 2016). "Moon was produced by a head-on collision between Earth and a forming planet". UCLA newsroom. UCLA.
↑ Herwartz, D.; Pack, A.; Friedrichs, B.; Bischoff, A. (2014). "Identification of the giant impactor Theia in lunar rocks". Science. 344 (6188): 1146–1150. Bibcode:2014Sci...344.1146H. doi:10.1126/science.1251117. PMID 24904162. S2CID 30903580.
↑ Meier, M. M. M.; Reufer, A.; Wieler, R. (2014). "On the origin and composition of Theia: Constraints from new models of the Giant Impact". Icarus. 242: 316–328. arXiv:1410.3819. Bibcode:2014Icar..242..316M. doi:10.1016/j.icarus.2014.08.003. S2CID 119226112.
↑ "A New Model for the Origin of the Moon". SETI Institute.
↑ Budde, Gerrit; Burkhardt, Christoph; Kleine, Thorsten (2019-05-20). "Molybdenum isotopic evidence for the late accretion of outer Solar System material to Earth". Nature Astronomy (英文). 3 (8): 736–741. Bibcode:2019NatAs...3..736B. doi:10.1038/s41550-019-0779-y. ISSN 2397-3366. S2CID 181460133.

[TheiaPothesis-1] "The Theia Hypothesis: New Evidence Emerges that Earth and Moon Were Once the Same". The Daily Galaxy. 2007-07-05. 原著喺2008-02-20歸檔. 喺2013-11-13搵到. {{cite web}}: Unknown parameter |dead-url= ignored (|url-status= suggested) (help)

[2] Murdin, Paul (2016). Rock Legends: The Asteroids and Their Discoverers. Springer. p. 178. Bibcode:2016rlat.book.....M. doi:10.1007/978-3-319-31836-3. ISBN 9783319318363.

[3] "Selene | Origin and meaning of selene by Online Etymology Dictionary".

[Stereo-4] 4.0 ^4.1 "STEREO Hunts for Remains of an Ancient Planet near Earth". NASA. 2009-04-09. 原著喺2013-11-13歸檔. 喺2013-11-13搵到.

[ReuferMeier2012-5] Reufer, Andreas; Meier, Matthias M. M.; Benz, Willy; Wieler, Rainer (2012). "A hit-and-run giant impact scenario". Icarus. 221 (1): 296–299. arXiv:1207.5224. Bibcode:2012Icar..221..296R. doi:10.1016/j.icarus.2012.07.021. S2CID 118421530.

[JutziAsphaug2011-6] Jutzi, M.; Asphaug, E. (2011). "Forming the lunar farside highlands by accretion of a companion moon". Nature. 476 (7358): 69–72. Bibcode:2011Natur.476...69J. doi:10.1038/nature10289. PMID 21814278. S2CID 84558.

[Astronomy-7] "Faceoff! The Moon's oddly different sides", Astronomy, August 2014, 44–49.

[Nace2016-8] 8.0 ^8.1 Nace, Trevor (2016-01-30). "New Evidence For 4.5 Billion Year Old Impact Formed Our Moon". Forbes. 喺2016-01-30搵到.

[9] Young, E. D.; Kohl, I. E.; Warren, P. H.; Rubie, D. C.; Jacobson, S. A.; Morbidelli, A. (28 January 2016). "Oxygen isotopic evidence for vigorous mixing during the Moon-forming giant impact". Science. 351 (6272): 493–496. arXiv:1603.04536. Bibcode:2016Sci...351..493Y. doi:10.1126/science.aad0525. PMID 26823426. S2CID 6548599.

[10] Wolpert, Stuart (January 28, 2016). "Moon was produced by a head-on collision between Earth and a forming planet". UCLA newsroom. UCLA.

[HerwartzPack2014-11] Herwartz, D.; Pack, A.; Friedrichs, B.; Bischoff, A. (2014). "Identification of the giant impactor Theia in lunar rocks". Science. 344 (6188): 1146–1150. Bibcode:2014Sci...344.1146H. doi:10.1126/science.1251117. PMID 24904162. S2CID 30903580.

[MeierReufer2014-12] Meier, M. M. M.; Reufer, A.; Wieler, R. (2014). "On the origin and composition of Theia: Constraints from new models of the Giant Impact". Icarus. 242: 316–328. arXiv:1410.3819. Bibcode:2014Icar..242..316M. doi:10.1016/j.icarus.2014.08.003. S2CID 119226112.

[13] "A New Model for the Origin of the Moon". SETI Institute.

[14] Budde, Gerrit; Burkhardt, Christoph; Kleine, Thorsten (2019-05-20). "Molybdenum isotopic evidence for the late accretion of outer Solar System material to Earth". Nature Astronomy (英文). 3 (8): 736–741. Bibcode:2019NatAs...3..736B. doi:10.1038/s41550-019-0779-y. ISSN 2397-3366. S2CID 181460133.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]