Q2：如果fission成立的话月球会是什么样子？ Spin faster than now Q3：如果俘获论是正确的话，如何加强？ Spin slower than now Q4：以下哪个为真，会削弱the objectionto俘获说capture？（注意！双否定！） 对：月球的core其实要更大一些； （错）科学家对月球表面元素的分析有错误； （错）月球crater的厚度被低估；
Q1：如果月球是CAPTURE来的，那么一下哪个为真 Q2：如果月球是和地球同时形成的，它应该具有和地球类似的组成。（选：月球上挥发金属会更多) Q3：假如第二个理论（地月同时产生）是真的话，月亮会怎样。（选：核会很大) Q4：以下哪个点成立可以削弱科学家的结论。（选：月亮的内核其实比科学家原来预测的大） Q5：if the fission(分裂学说） model is true, the moon that differ the current is 。。（就是如果fission是正确的，月亮会与现在的有什么不同。） 几经上说是spin faster or slower. 当时做题的时候出现了spin slower，但是回文中定位发现in fission model earth and moon have much more spin. 就是说要快，所以这个不对，我选择的是月亮周围会有很多Material.因为定为第一段说fission是地球甩出去很多物质。 Q6：哪个现象出现在同时形成这个学说 中，JJ是说选moon size的，但是题目中有两个跟size有关，一个是the moon size relative to earth. 一个是the size of moon core. 选后面一个，确定。 Q7：以下哪个如果为真，将会对capture的反驳（记得是反驳！）理论造成冲击，我选的如果发现月球的core其实要大一点。 Q8：主旨题
参考文献： THX to Steven Ren, who find it in WIKI Several mechanisms have been historically proposed for the Moon's formation 4.527 ± 0.010 billion years ago, some 30–50 million years after the origin of the Solar System.[15] These include the fission of the Moon from the Earth's crust throughcentrifugal forces,[16] which would require too great an initial spin of the Earth,[17] the gravitational capture of a pre-formed Moon,[18] which would require an unfeasibly extended atmosphere of the Earth to dissipate the energy of the passing Moon,[17] and the co-formation of the Earth and the Moon together in the primordial accretion disk, which does not explain the depletion of metallic iron in the Moon.[17] These hypotheses also cannot account for the high angular momentum of the Earth–Moon system.[19]
The prevailing hypothesis today is that the Earth–Moon system formed as a result of a giant impact: a Mars-sized body hit the proto-Earth, blasting material into orbit around the proto-Earth, which accreted to form the Moon.[20] Giant impacts are thought to have been common in the early Solar System. Computer simulations modelling a giant impact are consistent with measurements of the angular momentum of the Earth–Moon system, as well as the small size of the lunar core.[21]Unresolved questions are the relative sizes of the proto-Earth and impactor,[20] and how much material from these two bodies formed the Moon. However, recent oxygen isotope composition analysis of the Moon shows its oxygen isotope composition is more similar to the Earth's than this hypothesis would suggest.[22]
The large amount of energy released in the giant impact event and the subsequent reaccretion of material in Earth orbit would have melted the outer shell of the Earth, forming a magma ocean.[23][24] The newly formed Moon would also have had its own lunar magma ocean; estimates for its depth range from about 500 km to the entire radius of the Moon.[23]
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发表于 2012-12-6 13:04:48
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