首页
登录
职称英语
【B1】 [br] 【B8】 [originaltext]The origin of Earth’s moon, the largest moon in the
【B1】 [br] 【B8】 [originaltext]The origin of Earth’s moon, the largest moon in the
游客
2023-07-13
63
管理
问题
【B1】 [br] 【B8】
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
expect
解析
转载请注明原文地址:https://tihaiku.com/zcyy/2832590.html
相关试题推荐
【B1】[br]【B11】[originaltext]Italiansareknownforthemandtheoriessugge
【B1】[br]【B5】[originaltext]Italiansareknownforthemandtheoriessugges
【B1】[br]【B3】[originaltext]Italiansareknownforthemandtheoriessugges
[originaltext]Doyouhaveatoughmathtestcomingup?Thenlistentosome
[originaltext]Doyouhaveatoughmathtestcomingup?Thenlistentosome
[originaltext]Parentsshouldstopblamingthemselvesbecausethere’snota
[originaltext]Parentsshouldstopblamingthemselvesbecausethere’snota
[originaltext]SomestudentsattheOpenUniversityleftschool20yearsago.
[originaltext]SomestudentsattheOpenUniversityleftschool20yearsago.
[originaltext]SomestudentsattheOpenUniversityleftschool20yearsago.
随机试题
Oneofthemostcommonhumanfearsisscarcity.Manypeopleareafraidofno
WhatfirstinspiredMartinMiddleton’sinterestintravelling?[br][originalte
Manycountrieswillnotallowcigaretteadvertisingintheirnewspaperoron
A--NewYear’sDayB--Valentine’sDay
Sandy’sStoryA)Sandy,apoliteandfriendlyforty-
一沿x轴正方向的作用在一质量为3.0kg的质点上,已知质点的运动学方程为,则当时
以下关于高层建筑管道井等的叙述错误的是()。A.高层建筑的电缆井、管道井、排
高滴度核膜型抗核抗体,与下列何种疾病密切相关A:类风湿关节炎B:混合性结缔组织
精益化评价中,省公司运检部组织省评价中心每月对()及以下变电站问题整改情况进
户外高压熔断器更换过程中()。登高作业应使用合格的绝缘梯$;$应
最新回复
(
0
)