宇宙（2007）

The Universe S01E05

Part 4 April 22, 2021, 8:11 p.m.

所有叁个理论都有着重大的弱点.
The origin of the Moon remained a mystery.
月球的起源保持着神秘.
On July 20th 1969 US astronauts set foot on the lunar surface for the first time.
1969年7月20日,美国宇航员首次踏足月球表面.
That's one small step for man,
这是人的一小步,
one giant leap for mankind.
却是人类的一大步.
They had landed their lunar module on hardened lava plain
他们的登月舱登陆在坚硬的火山岩平原,
known as the Sea of Tranquility.
那里叫做宁静海.
And mission pilot Buzz Aldrin described the view as magnificent desolation.
宇航员Buzz Aldrin描述了看到的广阔荒凉的景象.
- Beautiful view... - Isn't that something?
-美极了...-有什么东西吗?
Magnificent sight down here.
下面的景色好宏伟.
The astronauts brought back 48 pounds of moon rocks and dusty soil,
宇航员带回了48磅月球的岩石和土壤,
or regolith.
或风化层.
Reading you loud and clear. Our position 133:0-69:15.
大声清晰地读出你的位置.我们的位置在133:0-69:15.
Geologist at Johnson Space Center in Houston eagerly awaited their arrival.
休斯敦约翰逊航♥天♥中心的地质学家急切地等候着他们的归来.
The excitement when samples first came back was just electrical.
样本第一次被带回的刺♥激♥就象触电一样.
I mean, it was just incredible.
我的意思是,这真是难以置信.
Nobody really knew quite what to expect.
没有人真的完全知道自己所期待的.
And we realized right away that we had basaltic rocks
我们立即意识到这块玄武岩
like one might see in Hawaii.
就象夏威夷可能会看到的.
In fact very similar to rocks one would see in Hawaii.
事实上非常象会在夏威夷看到的石头.
The NASA geologist were intrigued to find not only basalts
美国航♥天♥局的地质学家私下希望看到的不仅仅是玄武岩,
but rocks of another sort.
而是另外一种石头.
Rocks called breccias.
石头叫角砾岩.
Breccias form during asteroid impacts.
角砾岩形成于小行星撞击.
So if you can imagine a large impact body hitting the Moon it's gonna be
所以你能想象如果一个巨大的物体撞击月球,
very chaotic, it's gonna throw up debris. Debris gonna come flying out this what
将会非常混乱,将会撞出碎片.碎片将会飞起,
ends up to be a crater after it's over and you can see the many craters on the Moon.
形成弹坑,结束后,在月球上看到许多弹坑.
This debris gets all jumbled up and lands on the ground around the crater
碎片乱七八糟地堆积在弹坑的四周,
and then it gets compacted with the heat generated by the crater
接着碎片会由弹坑产生的热融合在一起,
and gets turned into rocks that look very chaotic, you see.
转化成岩石,看起来非常混乱,你瞧.
All sorts of pieces in the rock in different sizes
石头里各种碎片有不同的大小,
different shapes, all pieces of the rock that are in the area that
不同的形状,那个区域石头里的所有碎片
impacting body impacted.
都是碰撞压实的.
We have just not seen anything like this on Earth.
在地球上就没有看到过这样的.
The Moon rocks soon began to tell a fascinating tale.
月球吃透不久就开始讲述了迷人的故事.
First the rocks and soil samples contain particles
首先石头和土壤的样本包含的粒子
indicating that the Moon must have been covered by a deep ocean of lava
标志了在形成之前月球必定覆盖了厚厚的
after it formed.
广阔的火山熔岩.
This notion was reinforced
这个从发现得到的补充概念
by the discovery that the rocks were lacking significantly
是石头缺少值得注意的
in what scientists call "volatile elements".
被科学家称之为"挥发性成分"的东西.
Volatile elements are those that can evaporate easily
挥发性成分是那些容易挥发的元素,
and they're for be lost when you heat up a rock.
是在加热石头时会消失的.
And some examples of volatile elements include water or potassium for example.
挥发性成分一些例子包括水,或钾等等.
And if you compare the bulk Earth rocks to lunar rocks
如果将地球岩石与月球岩石比较,
you find that lunar rocks are extremely parched.
会发现月球岩石非常的干.
It's like just they've been heated and they've
就象被加热过的,
lost a lot of their volatile elements.
就象失去了挥发性成分.
But along with this start contrasts,
但是顺着这个对比,
the lunar samples also revealed at least one astonishing similarity
月球样本也显示出在月球表面与
between the lunar surface and rocks and soil from Earth.
地球上的岩石土壤之间至少有一个令人吃惊的相似之处.
The isotopes of individual elements, like oxygen in particular.
个别元素的同位素象氧有些特别.
There are different forms of oxygen.
氧有不同的形态.
The Moon had exactly the same ratios of different forms that the Earth did.
月球与地球相比,有这不同形态的相同比率.
But all the other rocks we knew from elsewhere in the solar system
但是我们掌握的来自太阳系其它地方的所有石块,
which are meteorites that fall out of space, all have different oxygen isotope ratios.
那些从太空落下的陨石,都具有不同的氧同位素的比率.
Which tells you that the Moon material and the Earth material are very very similar.
那些东西表明月球的物质与地球的物质非常非常地相似.
In the end the lunar samples had supplied a will for hard evidence,
最后月球样本提供了关于月球地质构造的
regarding the geological make up of the moon.
一个有力的证据.
But astronomers trying to understand the Moon's origin
然而天文学家试图了解月球的起源
were still left with the puzzle.
仍然感到困惑..
For William Hartmann, of the Planetary Science Institute in Tucson, Arizona,
对于亚利桑那州图森的行星科学学会的William Hartmann,
the information gleam from the Moon rocks supported some ideas
月球石块透露的一点信息支持了一些想法,
he's been working on for nearly a decade.
他几乎研究了十年.
Now a distinguished astronomer and painter of space images,
现在一位着名的天文学家兼太空画家,
in the early 60s Hartmann was a graduate student at the University of Arizona,
60年代早期,Hartmann是亚利桑那大学的研究生,
taking part in a project to map impact craters on the Moon.
参与了一个项目,为月球冲击坑绘制地图.
From the enormous basins, or seas to the smallest visible dimples.
从巨大的盆地,或许多看得见的最小的坑着手.
All I realized during this mapping in the 60s
这一切我认识到,在60年代绘制的大盆地的地图
that the big basins are actually impact features.
实际上是撞击的特征.
Very large asteroids hit the Moon
很大的小行星撞击了月球,
and made these huge explosions, some of them are 600 miles across.
产生了这些巨大的爆发,某些宽达600英里.
How big an object does it take to do that? Something like 100 miles across.
到底是多大的物体做到了这一点?大概有100英里宽.
So we had large object surrounding around the inner solar system
所以有大的物体游荡在太阳系里,
as the Earth was forming and they were crashing into planets.
当地球形成时,撞击着行星.
For Hartman, the notion that a 100 miles wide asteroid once impacted planets
对于Hartman,那个100英里宽的小行星撞击行星的概念,
bade a couple of questions.
提出了两个问题.
Could planet sized objects have ever collided?
行星大小的物体曾经碰撞过吗?
And could that have something to do with the formation of the Moon?
能够与月球的形成有关联吗?
By 1972 Hartmann and fellow Tucson astronomer Don Davis
1972年,Hartmann和伙伴图森天文学家Don Davis
had created a computer program to help them explore these ideas.
编写了一个计算机程序帮助解决这些问题.
The program made a rough attempt to simulate
程序粗略地模拟了
the accretion process in the early solar system.
早期太阳系的成长过程.
The astronomers wanted to see if any others planetary bodies
天文学家们希望看到会有其它行星物体
formed near the Earth and could have crashed into it.
在地球附近形成,并能够撞击它.
The idea was... if there was some other body there
这个概念是...如果那里有一些其它的物体,
and it finally crashes into the Earth,
并且最终撞击地球,
it blows off all this crustal material from the Earth...
将从地球撞出这所有的地壳物质...
As well as from the impacter itself.
同样也有撞击者自身.
Maybe the Moon could form out of that.
可能月球是在那个外面形成的.
Sure enough the simulation showed that a second planet
确实充分的模拟表明第二个行星
could have formed in the Earth's acquiescent zone.
会在地球默认的地带形成.
One about the size of Mars.
其大小相当于火星的大小.
It wasn't the Moon because it had formed from the same elements as the Earth
那不是月球,因为它与地球有着相同的元素,
and should therefore have had the same iron-core and heavy density as the Earth.
所以它应该有着与地球一样的铁核和密度.
The Moon of course does not.
月球当然不是这样的.
That was evidence enough for Hartmann to formulate a new fourth hypothesis.
Hartmann足够的证据陈述了新的第四个假设.
It came to be called: The Giant Impact theory.
被称为:巨大撞击理论.
In 1974 a new hypothesis explaining the origin of Earth's moon
1974年,解释地球的卫星来源的新假设,
debuted on the world scientific stage.
登上了世界科学的舞台.
Its proponents dubbed it: The Giant Impact theory.
它的支持者赋予它:巨大撞击理论.
The basic idea is that about 4.5 billion years ago
基本的概念是大约在45亿年前,
Earth collided with an object roughly the size of the current planet Mars.
地球被相当于现在的火星大小的物体撞击.
It's a very large collision.
这是非常巨大的撞击.
And it started the Earth's spinning.
它使得地球自转.
It's what gave us our current 24 hour day we believe.
我们认为它带来了今天的一天24小时.
And this collision was so massive
这个撞击是如此的沉重,
that it launched material into orbit around the Earth.
使得抛出的物质进入了围绕地球的轨道.
And it's for that material that we believe the Moon later coalesced.
而且对于那些物质,我们认为随后凝聚成了月球.
Dr. Robin Canup and others of the Southwest Research Institute in Boulder
博尔的西南研究学会的Robin Canup博士等人
have constructed a computer model to study the details
建立了一个计算机模型来研究
of the giant impact scenario.
巨大撞击设想的细节.
It divides off the Earth and this colliding rough protoplanet
它把地球和这个碰撞的粗野的原行星分别
into many different particles and then the evolution of each particle is tracked
放入不同的粒子,接着不同粒子通过碰撞进行演变.
through the course of the impact.
The simulation depicts the impact from a bird's eye view
模拟通过从上往下鸟瞰描述碰撞.
from the top-down.
The Earth was probably partly molten even before this impact.
地球甚至在撞击之前可能部分熔化了.
So initially the impacter came in from this direction,
所以最初碰撞在这个方向开始,
it hit the Earth with an off-center collision.
它撞击地球是个偏心的撞击.
And you can see the impacter has been stretched out
可以看到撞击延伸出来,
into this long arm of material, right here.
形成物质的长臂,就在这.
Scientists believe the upper layers of the Earth
科学家认为地球的上层
became completely molten following the impact.
随着撞击完全熔化.
The collision starts the Earth rotating.
撞击让地球开始旋转.
And you can also see that the collision has
同样能够看到撞击
substantially distorted the shape of the Earth itself.
充分扭曲了地球本身的形状.
After a couple hours we see that this arm of impacter material
几个小时后,看到撞击物质形成的长臂
has collapsed gravitationally into two large clumps.
由于引力崩塌成两个大块.
The inner clump of the impacter material
里面的大块
is actually composed overwhelmingly of the impacter's core.
实际上无可厚非,是撞击者的核.
So then when this inner clump recollides with the Earth,