“源来如此”——跟着备考族读新闻：月球的故事
Lunar affairs
A study inNatureadds a dramatic twist to the backstory of a neighbour we thought we knew.
08 April 2015 Nature
In the stories of many human cultures, the Solar System is something of a family affair. The Norse people and the Incas of South America believed that the Sun and the Moon were brother and sister. A Native American myth has them as husband and wife (although the husband wants to eat his children, the stars). The Moon as a mother is a common theme.
Now scientists have suggested a rival celestial tale with a twist that is more common to terrestrial television dramas: the sudden appearance of a long-lost sibling. The early Earth had a near-identical geological twin, they say. The two young planets, of course, had a falling out and the twin vanished. But before it did so, it saddled Earth with an orbiting Moon-child.
The the origin of the Moon is a classic story that has been told many times. The latest version — written in a research paper on page 212 — still has some plot holes. But it is a cracking tale.
The time: some 4.5 billion years ago, in the earliest days of the Solar System. The place: hostile. A long time ago, if you like, in a galaxy not very far away. Thousands of adolescent protoplanets whizz around the Sun, bashing into each other, some breaking into smaller pieces and forming others as they soak up the freed materials. One of these protoplanets, lying not too far from the Sun and not too close, is what we now call Earth.
Enter, stage left, protoplanet Theia. Smaller than proto-Earth, it was raised in a similar neighbourhood. A chance meeting set the two on a collision course. The meeting is violent, and — here it helps if you imagine the most gravelly cinematic voice-over you can manage — life for both will never be the same again.
Theia becomes a giant cloud of dust infused with bits spewed from the injured proto-Earth, which quickly comes together to form the Moon. Earth gains a dependant.
The script might sound familiar; the plot more of a remake than of anything original. But here is the difference. Previously, many planetary scientists considered that it was too much of a stretch to say that young Theia and Earth were so closely related. It is much more plausible, given the chaos of the time, to present Theia as a random stranger. But that creates a continuity error: the mineral composition of rocks retrieved from the Moon is eerily similar to those of Earth.
Either Theia and Earth are related, or our best models of how the Moon formed are wrong. But if they are related, then why is it that the other bodies in the Solar System that we have studied seem to be so different from each other? What are the chances, given the number of objects out there at the time, that proto-Earth would be hit by a near clone?
The latest study runs computer simulations of those early days, to investigate the possible backstories of the major characters, including how and where they formed and their probable orbits. (A note to film directors: this bit is probably best presented as a montage.) The number crunching offers a realistic script: there is a one-in-five chance that proto-Earth and Theia could have formed at about the same distance from the Sun, so from the same stuff, and then run into each other to make the Moon. True, it is not a cut-and-dried ending that ties up all the loose ends before the credits roll. But all the best stories leave room for a sequel.
参考翻译：
《自然》里的一篇研究给我们自以为了解的邻居的背景故事增加了剧烈的转折。
更多精彩我们保存在备考族微信公众号“beikaozu”
在人类文明的故事里，太阳系里的故事就像家务杂事。挪威人和南美印卡人认为太阳和月亮是兄妹。美洲本土神话将他们看作夫妇（虽然丈夫想要吃掉他的孩子们：星星）。将月亮看作母亲是极为常见的主题。
现在，科学家们暗示了一个相对不一样的神仙故事，其中带有的情节转折，对于电视剧的神话故事而言极度常见：突然出现的失踪已久的兄妹。他们说，早期的地球有一个几乎一模一样的地质孪生兄弟。不出意料地，这两个星球闹翻了，所以另一个孪生兄弟消失了。但在它这样做之前，它给地球添上了一个围绕它旋转的月球宝宝作为负担。
月亮的起源是一个经典的故事，已被传颂多次。最新的文字版本是在212页的一份研究报告——仍有一些情节漏洞。但这是一个美妙的故事。
时间：大约45亿年前，在太阳系的早期。地点：敌对状态。很久很久以前，换句话说，在一个并不是非常遥远的星系。成千上万个未成熟的原行星绕着太阳嗖嗖作响，彼此相撞。有一些破裂成更小的碎片，它们吸收了被释放出来的物质，形成了其他物体。这些原行星中的一个，距离太阳不近又不远的，就是我们现在叫做地球的星球。
从左侧进入上台的是忒伊亚原行星。它比原地球小，是在一个相似的环境下形成的。偶然的机会让这两个星球处在同一个碰撞的轨道上。这个碰面是很暴力激烈的，它帮助你想象一下最沙哑的电影嗓音——超出你能掌控的——碰撞过后双方的生活都不再可能一模一样了。
忒伊亚变成了一团巨大的尘烟云，其中充满了从受到伤害的原地球喷涌而出的物质，它们迅速地聚集到一起，形成了月球。地球获得了家眷。
这个脚本听起来很熟悉，情节更像对原始版本的重新塑造。但这里有个不一样的地方。在之前，很多行星科学家认为，将年轻的忒伊亚行星和地球认为密切相关，这是过度发挥。更看似合理的解释是，考虑到时间混乱无序，将忒伊亚展现成一个随意的外来者。但那样生成了一个持续性的错误：从月球上取得的岩石，其中的矿物质组成和地球离奇地相似。
要么忒伊亚和地球联系密切，或者我们关于月球如何形成的模式是错误的。但是，如果它们之间有联系，为什么太阳系中我们研究过的其他星体之间那么不同？考虑到同一时间同时存在的星球的数目，原地球被附近的复制星球撞击的几率有多大？
最新的研究使用了早期电脑模拟，调查可能的背景故事里的主要角色，包括它们是如何以及在哪里形成它们可能的轨道的。（给电影导演的一个提示：这部分最好展示为蒙太奇。）共同处理的数字提供了一个现实主义的脚本：有五分之一的可能性，地球和忒伊亚会在离太阳相同的距离外形成，所以，源于同样物质然后互相撞击形成了月球。确实，这不是一个落入俗套的结局，在字幕滚动之前将所有的松散的结果串联在一起。但所有最好的故事都给续集遗留了空间。
A study inNatureadds a dramatic twist to the backstory of a neighbour we thought we knew.
08 April 2015 Nature
In the stories of many human cultures, the Solar System is something of a family affair. The Norse people and the Incas of South America believed that the Sun and the Moon were brother and sister. A Native American myth has them as husband and wife (although the husband wants to eat his children, the stars). The Moon as a mother is a common theme.
Now scientists have suggested a rival celestial tale with a twist that is more common to terrestrial television dramas: the sudden appearance of a long-lost sibling. The early Earth had a near-identical geological twin, they say. The two young planets, of course, had a falling out and the twin vanished. But before it did so, it saddled Earth with an orbiting Moon-child.
The the origin of the Moon is a classic story that has been told many times. The latest version — written in a research paper on page 212 — still has some plot holes. But it is a cracking tale.
The time: some 4.5 billion years ago, in the earliest days of the Solar System. The place: hostile. A long time ago, if you like, in a galaxy not very far away. Thousands of adolescent protoplanets whizz around the Sun, bashing into each other, some breaking into smaller pieces and forming others as they soak up the freed materials. One of these protoplanets, lying not too far from the Sun and not too close, is what we now call Earth.
Enter, stage left, protoplanet Theia. Smaller than proto-Earth, it was raised in a similar neighbourhood. A chance meeting set the two on a collision course. The meeting is violent, and — here it helps if you imagine the most gravelly cinematic voice-over you can manage — life for both will never be the same again.
Theia becomes a giant cloud of dust infused with bits spewed from the injured proto-Earth, which quickly comes together to form the Moon. Earth gains a dependant.
The script might sound familiar; the plot more of a remake than of anything original. But here is the difference. Previously, many planetary scientists considered that it was too much of a stretch to say that young Theia and Earth were so closely related. It is much more plausible, given the chaos of the time, to present Theia as a random stranger. But that creates a continuity error: the mineral composition of rocks retrieved from the Moon is eerily similar to those of Earth.
Either Theia and Earth are related, or our best models of how the Moon formed are wrong. But if they are related, then why is it that the other bodies in the Solar System that we have studied seem to be so different from each other? What are the chances, given the number of objects out there at the time, that proto-Earth would be hit by a near clone?
The latest study runs computer simulations of those early days, to investigate the possible backstories of the major characters, including how and where they formed and their probable orbits. (A note to film directors: this bit is probably best presented as a montage.) The number crunching offers a realistic script: there is a one-in-five chance that proto-Earth and Theia could have formed at about the same distance from the Sun, so from the same stuff, and then run into each other to make the Moon. True, it is not a cut-and-dried ending that ties up all the loose ends before the credits roll. But all the best stories leave room for a sequel.
参考翻译：
《自然》里的一篇研究给我们自以为了解的邻居的背景故事增加了剧烈的转折。
更多精彩我们保存在备考族微信公众号“beikaozu”
在人类文明的故事里，太阳系里的故事就像家务杂事。挪威人和南美印卡人认为太阳和月亮是兄妹。美洲本土神话将他们看作夫妇（虽然丈夫想要吃掉他的孩子们：星星）。将月亮看作母亲是极为常见的主题。
现在，科学家们暗示了一个相对不一样的神仙故事，其中带有的情节转折，对于电视剧的神话故事而言极度常见：突然出现的失踪已久的兄妹。他们说，早期的地球有一个几乎一模一样的地质孪生兄弟。不出意料地，这两个星球闹翻了，所以另一个孪生兄弟消失了。但在它这样做之前，它给地球添上了一个围绕它旋转的月球宝宝作为负担。
月亮的起源是一个经典的故事，已被传颂多次。最新的文字版本是在212页的一份研究报告——仍有一些情节漏洞。但这是一个美妙的故事。
时间：大约45亿年前，在太阳系的早期。地点：敌对状态。很久很久以前，换句话说，在一个并不是非常遥远的星系。成千上万个未成熟的原行星绕着太阳嗖嗖作响，彼此相撞。有一些破裂成更小的碎片，它们吸收了被释放出来的物质，形成了其他物体。这些原行星中的一个，距离太阳不近又不远的，就是我们现在叫做地球的星球。
从左侧进入上台的是忒伊亚原行星。它比原地球小，是在一个相似的环境下形成的。偶然的机会让这两个星球处在同一个碰撞的轨道上。这个碰面是很暴力激烈的，它帮助你想象一下最沙哑的电影嗓音——超出你能掌控的——碰撞过后双方的生活都不再可能一模一样了。
忒伊亚变成了一团巨大的尘烟云，其中充满了从受到伤害的原地球喷涌而出的物质，它们迅速地聚集到一起，形成了月球。地球获得了家眷。
这个脚本听起来很熟悉，情节更像对原始版本的重新塑造。但这里有个不一样的地方。在之前，很多行星科学家认为，将年轻的忒伊亚行星和地球认为密切相关，这是过度发挥。更看似合理的解释是，考虑到时间混乱无序，将忒伊亚展现成一个随意的外来者。但那样生成了一个持续性的错误：从月球上取得的岩石，其中的矿物质组成和地球离奇地相似。
要么忒伊亚和地球联系密切，或者我们关于月球如何形成的模式是错误的。但是，如果它们之间有联系，为什么太阳系中我们研究过的其他星体之间那么不同？考虑到同一时间同时存在的星球的数目，原地球被附近的复制星球撞击的几率有多大？
最新的研究使用了早期电脑模拟，调查可能的背景故事里的主要角色，包括它们是如何以及在哪里形成它们可能的轨道的。（给电影导演的一个提示：这部分最好展示为蒙太奇。）共同处理的数字提供了一个现实主义的脚本：有五分之一的可能性，地球和忒伊亚会在离太阳相同的距离外形成，所以，源于同样物质然后互相撞击形成了月球。确实，这不是一个落入俗套的结局，在字幕滚动之前将所有的松散的结果串联在一起。但所有最好的故事都给续集遗留了空间。