了解宇宙是如何运行的（2010）

How the Universe Works S08E01

Part 12 Jan. 30, 2022, 2:57 p.m.

the planet cooled by 20 degrees.
在附近地区，破坏更加巨大
In the immediate area, there's
just tremendous destruction.
一切都毁了
Just everything gets destroyed.
但从长远来看，事件让大气中
But over the long term,
you're talking about ash
布满了火山灰，导致极端寒冷的天气
kicked up in the atmosphere,
extremely cold weather,
基本上是一个全球性冰河时代
basically a global ice age.
低温冻死了
Narrator: The freezing
temperatures killed off
大多数植物
most plant life.
奥卢西:想象一下这对地球上的生命有什么影响
Oluseyi: Imagine how that
affected life on earth.
没有植物，生态系统的基础就会崩溃
No plants and the base
of the ecosystem collapses.
这个黑暗的核冬天持续了两年
Narrator: This dark nuclear
winter lasted two years
阻止了植物的光合作用
and prevented plants
from photosynthesizing.
所以如果植物不能再利用光合作用生存
So if plants can no longer
use photosynthesis
它们就会死亡
to live, they'll die.
没有植物，这些大型动物
And then with no plants,
then you have no food
就没有食物
for these larger animals.
所以任何吃这些值物的动物也会死亡
And so anything that eats
those animals will also die.
如果大地失去了植物
If you lose your plants,
那么也将会失去大规模的生命
you're going to lose
your large scale life.
首先，以植物为食的食草动物灭绝了
Narrator: First the plant eating
herbivores died off,
接着是食肉动物
followed by the meat eating
carnivores.
大多数恐龙无法找到食物
Most of the dinosaurs
were just unable to find food
无法熬过寒冷的漫漫长夜
and to survive through
the cold long night.
这场全球性的灾难还没有结束
Narrator: The global devastation
wasn't over yet.
小行星撞击的大♥陆♥架岩石
The rock of the continental
shelf where the asteroid hit
含有碳和硫
contained carbon and sulfur.
兰扎:这些碳酸盐岩被加热和汽化
Lanza: These carbonate rocks
were heated and vaporized
释放出二氧化碳到大气中
and released carbon dioxide
into the atmosphere.
又是一种温室气体
Yet another greenhouse gas.
所以你蒸发了很多硫
So you're vaporizing
a lot of sulfur,
和很多不同种类的盐
a lot of salts
of different kinds
然后被上升到上层大气
that are then lofted up
into the upper atmosphere,
这对气候造成了严重破坏
that then plays havoc
on the climate.
这些温室气体在大气中聚集
Narrator: These greenhouse gases
built up in the atmosphere
形成了一个暖毯
forming a warming blanket.
触发下一阶段的破坏
Triggering the next phase
of destruction.
全球变暖加剧
Global warming on steroids.
气温比正常水平高出10度
Temperatures rose 10 degrees
above normal.
然后海洋也变暖了
Then the oceans warmed,
as well.
氧气含量下降，海洋对于简单的生命形式
Oxygen levels dropped,
and the seas became toxic
变得有毒
to simple life forms.
它实际上使某些微生物无法生存
It actually made it impossible
for certain microbes
而它们实际上是食物系统的基础
to actually live, and they're
the basis of the food system.
所以它真的改变了海洋里的
So really it changed what could
actually live in the ocean
生物种类和数量
and how much could live there.
海洋中出现了死亡区
Narrator: Dead zones appeared
in the oceans
就像陆地上一样
just as they had on land.
地球上近四分之三的生命
Nearly three quarters
of all life on earth died,
都死于这次小行星撞击
all from one asteroid impact.
为了防止这种情况再次发生
To prevent it
from happening again,
我们需要追踪所有有潜在危险的小行星
we need to track all
potentially dangerous asteroids.
但这并不容易
But that isn't easy
因为这些太空岩石可以改变方向
because these space rocks
can change direction.
♪
土耳其萨里切克
narrator: Saricicek, turkey.
监控录像记录下了天空中的一道闪光
Security cameras record
a flash in the sky.
这道闪电——一颗三英尺高的小行星在大气层中爆♥炸♥
The flash -- a 3-foot asteroid
exploding in the atmosphere.
♪
兰扎:它在大气中爆♥炸♥，然后下雨
lanza: It blew up in
the atmosphere and rained down,
人们都看到了
and people saw that.
这是非常值得注意的
It was very noticeable.
他们过去，收集了那些陨石
And they went, and they
collected those meteorites.
然后他们试图弄清楚他们看到的是什么
And then they tried to figure
out what they were looking at.
碎片被送去进行碎片分♥析♥
Narrator: The debris was sent
for fragment analysis.
我这里有一块首先，在外面
I have a piece of one here.
So first, on the outside,
你可以看到它有一个黑色的核聚变外壳
you can see it has
a really black fusion crust.
这是它坠落到地球大气层时的痕迹
This is from when it fell
into the earth's atmosphere,
所以它被融化了
so it was melted.
但当你看它的内部时
But when you look on
the inside, it reveals
你会发现这是一种有着美丽的、非常轻的色调的材料，并且纹理精细
this beautiful, very light tone,
fine grained material.
所以这些陨石非常独特
And so these meteorites
are incredibly distinctive
非常漂亮
and really beautiful.
这些陨石是岩石的
Narrator:
The meteorites are rocky.
它们美丽的颜色来自一种叫做灰榴石的矿物
They're beautiful color comes
from a mineral called howardite.
它很罕见，而且不会在地球上形成
It's rare, and it doesn't
form on earth.
灰榴石陨石来自灶神星小行星
Howardite meteorites come from
the asteroid vesta,
我们之所以知道这一点，是因为黎明号♥拜访过灶神星
and we know that because
of the dawn mission
并且非常仔细地观察了它
that actually went to vesta
and took a look at it
所以我们非常清楚它的组成
very carefully, so we know
the composition very well.
所以现在突然在土耳其出现了一种新的陨石
And so now suddenly here
was a new kind of meteorite
它与灶神星的陨石家族相匹配
that's in turkey that matches
the vesta family of meteorites
但我们如何能确定这些太空岩石碎片
narrator: But how can we be sure
that these bits of space rock
来自灶神星，这颗1亿英里（约1.6亿公里）外的小行星
came from vesta, an asteroid
over 100 million miles away.
这是坠落的陨石，所以这意味着
It was a fall meteorite,
and so what that means
有人看到了它，你知道，我们看到了它的坠落
is that someone saw it,
you know, we saw it fall.
所以我们知道它的轨迹
And so we knew its trajectory.
所以我们可以反过来问
So we could actually
work backwards to say,
这块陨石是从哪里来的？
where did that meteorite
come from?
通过追踪
Narrator: Retracing
the trajectory of
土耳其陨石的轨迹，科学家们找到了
the turkish meteorites took
the scientists all the way back
328英里（约528公里）宽的灶神星
to the 328-mile wide vesta.
在研究灶神星表面的地方
Where they studied
vesta's surface,
他们发现了进一步的证据
they found further evidence.
在灶神星的表面，实际上有一个非常大的
On the surface of vesta,
there's actually a very large
新撞击坑，它的年代
and fresh impact crater
that is around the same age
和土耳其陨石差不多
of the turkish meteorite.
这就解决了问题
So that really clinched it.