了解宇宙是如何运行的（2010）

How the Universe Works S08E01

Part 6 Jan. 30, 2022, 2:57 p.m.

然后反弹
And as that rebound
is occurring,
当反弹发生时，物质就会被
that's when the material
is being ejected
喷射出陨石坑
out of the crater itself.
你会看到它的表面向外喷发
You'll see the surface
erupting outwards
就像一些巨大的石花盛开的花瓣
like the blooming petals
of some big rocky flower
所有这些碎片向各个方向喷射
as all this debris goes
spraying out in every direction.
♪
这颗150英尺高的小行星
narrator: The 150-foot
barringer asteroid
将岩石变成了粉末
turned the rock to powder.
6600万年前
66 million years ago,
一颗比巴林杰大200倍
an asteroid
around 200 times larger
移♥动♥速度比巴林杰快1.5倍的小行星
and moving
one and a half times faster
撞击了地球
than barringer hit earth.
这颗小行星——被称为 k-pg ——
This asteroid impact --
called k-pg --
能量巨大
had so much energy,
把岩石变成了液体
it turned rock
to liquid.
这东西是巨大的你很难想象
This thing was immense.
It's really hard to wrap
它到底有多大
your head around
just how big it is.
当它撞上它的后端时，它反弹得如此之远
When it hits the back end of it,
it is so far back,
以至于现代喷气客机可以在那里飞行
that it's where
a modern jetliner would fly.
k-pg 小行星撞击地面的
Narrator: The k-pg asteroid
hit the ground
质量和速度是致命的
with a lethal combination
of mass and speed.
一万亿吨♥的质量，以每小时45000英里(约72400公里)的速度飞行
A trillion tons traveling
at 45,000 miles an hour.
有些岩石完全蒸发了
Some rock is
completely vaporized.
它变成了气体
It just becomes a gas.
有一些岩石融化了
You have some rock
that is melted.
还有一些被扔到太空中
You have some
that's thrown out into space.
这些物质向上穿过，然后落下
This material goes up
through that and then falls down
落在一大♥片♥区域中
and settles down
over a huge area.
可能是灰尘也可能是粉碎的岩石
That might be dust.
It might be pulverized rock.
甚至可能是汽化的金属
It might be vaporized metal.
到处都是滚烫的材料
It's all of this hot material
raining down everywhere.
一些岩石向天空爆♥炸♥
Narrator: Some of the rock
exploded skywards,
但地表以下的岩石
but rock below the surface
was slammed by a shockwave
被一种完全无法想象的冲击波击中
that was completely
off the charts.
岩石不再像岩石一样运动了
Rock stopped behaving
like rock.
在我们的体验中，岩石是固体
We experience rocks
as solid objects,
但如果你撞击岩石的力度足够大
but if you hit a rock
hard enough,
它就会像水一样流动
it flows like water.
k-pg 小行星撞击得太厉害了
Narrator: The k-pg asteroid
hit so hard,
把岩石磨成粉末
it pulverized the rock,
变成了液体
turning it into liquid.
就像扔进池塘的石头
Almost like ripples
on a pond moving away
激起的涟漪一样
from a stone
that's been dropped in it.
杜尔达:这就像地球本身的
Durda: It's almost like a splash
固体岩石飞溅出来
in the solid body
of the earth itself,
就像水滴在水中飞溅一样
and like water droplets
splashing in water,
你会看到中心山峰会飞溅起来
you'll see that central peak
will kind of splash up
上升到很高的高度，然后又回落
and rise to a high altitude
and then come back down again.
我们认为类似的过程
We think a process very similar
to that probably happened
可能发生在陨石坑中心的岩石本体
in the rock itself
at the center of the crater,
上升到喜马拉雅山的高度
rising up
as high as the himalayas
然后又回落到现在的位置
before relaxing back down
to their current position again.
普列斯科:这些物质会下沉，所以这些涟漪
Plesko: The material slumps,
and so these ripples
会冻结在岩石中
are frozen in the rock,
而其他的碎片会呈放射状消失
and there are other fragments
that go away radially,
就像玻璃被子弹击中后
almost like the spider web
pattern in glass
形成的蛛网图案一样
that you get after
it's shot with a bullet.
k-pg 撞击形成了一个111英里（约179公里）宽的
Narrator: The k-pg impact
blew out a crater
陨石坑
111 miles wide.
它是地球上已确认的
It is the third largest
confirmed
第三大撞击结构
impact structure on earth.
一个巨大而快速的小行星
A large and fast asteroid
heading our way
朝我们飞来总是个问题
is always going to be a problem.
我们该怎么做？
So what do we do?
等待然后遗忘？
Wait for oblivion?
还是反击？
Or fight back?
♪
太阳系内部的空间
narrator: The space
in the inner solar system
似乎平静、稳定、空虚
seems calm, stable, and empty.
然而并不
It's not.
有成千上万的近地物体
There are tens of thousands
of near earth objects
在地球周围呼啸而过
just whizzing around earth.
现在，空间很大
Now, space is big.
它们不会每次绕太阳运行时都撞击我们
They're not gonna hit us
every time they orbit the sun,
但这确实提供了一种可能性
but this does set up
the possibility
那就是，在未来的某一年
that, one of these years,
我们将在太空中同一时间
we're gonna end up
at the same spot in space
到达与小行星♥相♥同的地点
at the same time
as that asteroid,
然后就会发生撞击
and then it's gonna be
an impact.
我们生活在一个宇宙射击场
We're living in a cosmic
shooting gallery.
历史上小行星撞击地球
Asteroids strike the earth
all the time
一直都在发生
through history,
将来也会发生
and it's gonna happen again.
科学家们正在研究
Narrator: Scientists are
developing strategies
阻止小行星撞击地球的策略
to stop an asteroid
from hitting our planet.
我们的选择——摧毁或改变太空岩石的方向
Our options -- destroy
or deflect the space rock.
但首先，我们需要探测到任何向我们飞来的
But first, we need to detect
any dangerous asteroids
危险小行星
heading our way.
斯特里克:当知道我们还没有探测到
Stricker: It's a little bit
unnerving to know
所有可能穿越我们轨道的小行星时
that we haven't yet detected
all of the asteroids
这有点令人很不安
that exist that could
possibly cross our path.
我们现在已经发现了很多小行星
We've discovered
a lot of asteroids now,
但我们通常发现的是较大的小行星
but we typically discover
the big ones.
但是对于100英尺以下的小行星来说
But for asteroids
that are below 100 feet,
还有很多我们没有发现的地方
there's a lot still out there
that we haven't discovered.
如果这颗小行星在人口稠密的地区爆♥炸♥
And such an asteroid