首页
登录
职称英语
【B1】 [br] 【B10】 [originaltext]The origin of Earth’s moon, the largest moon in th
【B1】 [br] 【B10】 [originaltext]The origin of Earth’s moon, the largest moon in th
游客
2024-02-14
29
管理
问题
【B1】 [br] 【B10】
The origin of Earth’s moon, the largest moon in the solar system, is still something of a mystery. There are some theories about its origin however. Now, keep in mind that a theory of the moon’s origin has to be consistent with two important facts. The first fact is that the Earth contains a lot of iron, most of it has an iron core. But the moon contains practically no iron. The second fact is that other than the difference in iron content, the moon and Earth are composed of the same minerals, a similarity not shared with any other planet or moon in our solar system. One of the earliest theories of the moon’s origin, I called it the Capture Theory, proposes that the moon was somehow captured by Earth’s gravitational force. This theory is improbable, however, because it assumes that the moon and Earth formed in different parts of the solar system. If this was true you would expect the moon’s composition to be much different from Earth’s composition, just as all the other planets in the solar system are so different from Earth. A second theory of the moon’s origin is more promising. It is sometimes referred to as the Mars Theory, because according to this theory, when Earth was still in formation, it was struck by a planet about the size of Mars. The impact caused the cores of the two planets to melt together and chunks of Earth’s crust to be thrown out into space. These chunks came together to form the moon. Now, remember, Earth’s crust is low in iron, because the iron is in Earth’s core, but high in various other minerals. This then accounts for why there is little iron but lots of other minerals on the moon.
选项
答案
it was struck by a planet about the size of Mars
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3448858.html
相关试题推荐
[originaltext]Bowsandarrowsareoneoftheman’soldestweapons.Theygav
[originaltext]M:Right,let’sgetontothemarketingstrategy.W:Well,thema
[originaltext]M:Right,let’sgetontothemarketingstrategy.W:Well,thema
[originaltext]W:Tonyisthebestcross-countryrunnerwe’veeverhadinthiss
[originaltext]W:Tonyisthebestcross-countryrunnerwe’veeverhadinthiss
[originaltext]W:Tonyisthebestcross-countryrunnerwe’veeverhadinthiss
[originaltext]W:Tonyisthebestcross-countryrunnerwe’veeverhadinthiss
[originaltext]W:Tonyisthebestcross-countryrunnerwe’veeverhadinthiss
[originaltext]W:Tonyisthebestcross-countryrunnerwe’veeverhadinthiss
[originaltext]Sportsmadgamesareveryusefulforcharactertraining.Int
随机试题
AnumberofyearsagoIsatdownonastonebenchoutsidetheTeatroAvenida
MichaelLewis,theauthorofLiar’sPoker,istheidealwritertoanalyzet
[originaltext]W:Hi,Bill.Howisyouroralpresentationcomingalong?M:What
[audioFiles]2018m6s/audio_ezfj_017_180602[/audioFiles]TaxOneofthemosti
Nodocumentissafeanymore.Fakingoncethedomainofskilleddeceiversth
[originaltext]Whenpeoplethinkofcarrots,theyusuallypictureintheirm
下列说法错误的是( )。A.流速的大小可以由流线的疏密程度来反映 B.流
CreditPortfolioView模型根据现实宏观经济因素通过()计算违
考虑一个基于不支付利息的股票的远期合约多头,3个月后到期。假设股价为40
根据《中华人民共和国野生动物保护法》,下列说法中,错误的是( )。A.国家保护
最新回复
(
0
)