地研认为 地球由两颗星行相撞而成.doc

地球由两颗星行相撞而成 张铁城 2016、2、3张铁城下载110 No.7参考消息2016/1/31地研认为 地球由两颗星行相撞而成英国每日电讯报：Earth is actually two planets, scientists concludeBySarah Knapton,Science Editor Telegraph 29 Jan 2016参考消息译文：【英国每日电讯报网站1月30日报道】题：科学家断定，地球其实是两颗行星(记者萨拉斯纳普顿)简介这篇是有关宇宙形成的科普文章。究竟这类语篇的词汇有多么难，还不知道，不妨做一项词汇级别统计词汇级别统计，看看：一级词汇是否占70%左右？现在我只把这个有857个英语单词的语篇的头100个单词的词汇级别统计一下，结果：一级词汇65个，占65.00%；一级、二级、三级词汇总计：83个，占83%。你如果不放心，自己可以试着完成全文词汇级别统计。附件中有关于词汇级别统计的说明，以及头100个单词的统计结果。The early Earth was mixed with a baby planet called Theia following a head on collision 4.5 billion years ago, scientists have foundTodays Earth is made up of early Earth and the embryonic planet TheiaPhoto: ALAMYBySarah Knapton,Science Editor12:56PM GMT 29 Jan 2016Earth is actually made up from two planets which came together in a head-on collisionthat was so violent it formed the Moon, scientists have concluded.Initially it was believed that theMoonwas created when a smaller planet called Theia grazed the Earth and broke up, sending a smaller chunk into space where it was caught in Earths gravity.But if that was the case the Moon would have a different chemical composition to the Earth, because it would be made up, predominantly, of Theia.Theia probably would have become a planet if the crash had not occurredProf Edward Young, University of CaliforniaHowever, after studying Moon rocks brought back by astronauts on the Apollo missions, scientists at theUniversity of Californiahave found that their oxygen isotopes are the same as on Earth.It means that the collision between Their and the early Earth was so violent that the two planets effectively melded together to form a new planet, a chunk of which was knocked off to form the Moon.“We dont see any difference between the Earths and the Moons oxygen isotopes; theyre indistinguishable,” said Edward Young, lead author of thenew studyand a UCLA professor of geochemistry and cosmochemistry.“Theia was thoroughly mixed into both the Earth and the Moon, and evenly dispersed between them.“This explains why we dont see a different signature of Theia in the Moon versus the Earth.”Professor Edward YoungThe crash with Theia happened approximately 100 million years after the Earth formed, almost 4.5 billion years ago.It was thought Theia had collided with Earth at an angle of 45 degrees or more, described by the report authors as a powerful side-swipeThe researchers analysed seven rocks brought to the Earth from theMoonby the Apollo 12, 15 and 17 missions, as well as six volcanic rocks from the Earths mantle - five from Hawaii and one from Arizona.The key to reconstructing the giant impact was a chemical signature revealed in the rocks oxygen atoms. More than 99.9 percent of Earths oxygen is O-16, so called because each atom contains eight protons and eight neutrons.But there also are small quantities of heavier oxygen isotopes: O-17, which have one extra neutron, and O-18, which have two extra neutrons.In 2014, a team of German scientists reported in Science that the Moon also has its own unique ratio of oxygen isotopes, different from Earths. The new research finds that is not the case.Lunar rock from Apollo 17, credit, Paul WarrenProf Youngs research team used state-of-the-art technology and techniques to make extraordinarily precise and careful measurements, and verified them with UCLAs new mass spectrometer.Theia, which did not survive the collision - except that it now makes up large parts of Earth and the Moon - was growing and probably would have become a planet if the crash had not occurred, added Prof Young.Prof Young and some other scientists believe the planet was approximately the same size as the Earth; although believe it was smaller, perhaps more similar in size to Mars.A head-on collision was initially proposed in 2012 by Matija Cuk, now a research scientist with the SETI Institute, and Sarah Stewart, now a professor at UC Davis; and, separately during the same year by Robin Canup of the Southwest Research Institute.The new research was published in the journalScience.William K. Hartmann painted this rendering of the first moments of impact参考消息译文：【英国每日电讯报网站1月30日报道】题：科学家断定，地球其实是两颗行星(记者萨拉斯纳普顿)研究认为地球由两颗行星相撞而成2016年02月01日 08:37参考消息【英国每日电讯报网站1月30日报道】题：科学家断定，地球其实是两颗行星(记者萨拉斯纳普顿)科学家断定，地球其实是由两颗行星迎面相撞而成：这场碰撞极为激烈，形成了月球。起初，人们认为，一颗名叫忒伊亚、比地球略小的行星与地球擦肩相撞，忒伊亚解体后产生的一个碎块被地球引力捕获后形成了月球。可如果真是这样，月球的化学构成就应该与地球完全不同，因为月球主要由忒伊亚构成。然而，加利福尼亚大学的科学家研究了参加阿波罗登月行动的宇航员从月球带回的岩石后发现，月球的氧同位素与地球相同。这意味着忒伊亚和早期地球的碰撞如此剧烈，以至于两颗行星实际上合并在一起形成一颗新行星，其中有一块掉下来形成月球。这项新研究报告的第一作者、加利福尼亚大学洛杉矶分校地球化学与天体化学家爱德华扬说：“我们在地球和月球的氧同位素之间没有发现任何区别，二者完全一样。”他说：“忒伊亚完全成为地球和月球的一部分，甚至在它们内部散开。这解释了为什么我们没有在月球上发现不同于地球的忒伊亚的特征。”这次相撞大约出现在地球形成后1亿年，也就是近45亿年以前。研究人员分析了阿波罗12号、阿波罗15号和阿波罗17号带回来的七块岩石，以及六块源自地幔的火山岩(其中五块来自夏威夷，一块来自亚利桑那)。重现这次激烈撞击的关键在于这些岩石的氧原子上的化学标记。地球上的氧有99.9%以上为氧-16，因为每个氧原子含有8个质子和8个中子。但是，地球上也存在少量较重的氧同位素，氧-17和氧-18，分别比氧-16多出一个中子和两个中子。2014年，一个德国科学家小组在科学杂志撰文称，月球有不同于地球的独特的氧同位素比例。但是，这项新研究发现，情况并非如此。附件头100个单词的词汇级别统计如下：【但是不包括这个文本内所有注释/译文中的英语单词】全文共计100个英语单词，其中：一级词汇65个，占65.00%；二级词汇14个，占 14%；三级词汇 4个，占 4%；级词汇 10个，占 10%；无级词汇7个，占 7%；一级、二级、三级词汇总计：83个，占83%。Earth is actually two（） planets（）, scientists conclude BySarah Knapton,Science Editor Telegraph 29 Jan 2016The early Earth was mixed with a baby planet（）called Theia following a head on collision（） 4.5 billion（） years ago, scientists have foundTodays Earth is made up of early Earth and the embryonic【/embrink / adj at a very early stage of development】planet（） TheiaPhoto: ALAMYEarth is actually made up from two（） planets（）which came together in a head-on collision（）that was so violent it formed the Moon, scientists have concluded.Initially it was believed that theMoonwas created when a smaller planet（）called Theia grazed【/grez/ vT to touch something lightly（） while passing it, sometimes damaging it】the Earth and broke up, sending a smaller chunk into space （一）一级词汇统计：65个单词 【在这里，你将看到 “全国山河一片红”。】 is actually ByScience The early was with a baby called following a head on years ago, have foundTodays is made up of early and the is actually made up from which came together in a head-on that was so it formed the have it was believed that thewas created when a smaller called the and broke up, sending a smaller into space （二）二级词汇统计：14个单词 【在这里，你将看到 “蓝星点点无依靠”。】Earth scientists conclude Editor Earth mixed scientists Earth Earth PhotoEarth scientists concluded. Earth （三）三级词汇统计：4个单词 【在这里，你将看到 “粉色桃花随风飘”。】 violent Moon, .Initially Moon.（四）（）级词汇统计：10个单词 【在这里，你将看到 “棕色麻袋尘埃闹”。】 two planets planet collision billionplanet two planets collision planet （五）无级别词汇统计：7个单词 【在这里，你将看到 “漫天黑词意难表”。】Sarah Knapton Telegraph TheiaALAMY Theia grazed. 附件词汇级别的说明 格式有关词汇级别的几点说明： 词汇级别的依据分别是：（1）朗文当代高级英语辞典 英英英汉双解 外语教学与研究出版社或 灵格斯软件收入的朗文当代英语词典以下均简称朗文辞典（2）麦克米伦高阶英汉双解词典外语教学与研究出版社 或 灵格斯软件收入的麦克米兰英语词典 American以下均简称麦克米伦词典1、一级词