了解宇宙是如何运行的（2010）

How the Universe Works S06E04

Part 3 Dec. 22, 2021, 7:22 p.m.

如果这颗行星没有被喷射出我们的太阳系
Had this planet not been ejected out of our solar system,
我们就不会在这里
we wouldn't be here.
那么这个失踪的冰巨人现在在哪里？
So where is this missing ice giant now?
答案非常惊人
The answer is pretty amazing.
它可能就在银河系的
It could be clear across the other side
另一边
of the milky way galaxy.
太阳以每小时50万英里的速度
The Sun moves around the milky way galaxy
绕着银河系转
at about half a million miles an hour,
在地球的历史中
and in the history of the Earth,
我们大约已经绕了20圈了
we've been around about 20 times.
我们可能会在银河系的任何地方失去那颗行星
We could've lost that planet anywhere across the milky way.
但这第三个冰巨人
But is this third ice giant
是真的迷路了还是只是躲起来了？
really lost or just hiding?
2016年1月……加州理工学院的天文学家
January 2016... Astronomers at Caltech
宣布了一个惊人的消息
make an astonishing announcement.
他们声称已经发现了证据
They claim to have found evidence
证明在柯伊伯带外有一颗神秘的第九颗行星
of a mysterious ninth planet disrupting icy bodies
扰乱了冰冷的天体
far out in the Kuiper belt.
模拟表明，如果这颗所谓的第九行星存在
Simulations suggest that if this so-called planet nine exists,
它的大小与海王星和天王星♥相♥似
it is similar in size to Neptune and Uranus.
它会是地球的救世主吗？
Could this be Earth's savior?
太阳系中原本缺失的自我牺牲冰巨人
Could the solar system's primordial missing
有可能是第九行星吗？
sacrificial ice giant be planet nine?
是的,它可以是
Yes, it could.
也许这第三颗冰巨星
Perhaps this third ice giant
并没有从太阳系喷射出去
wasn't ejected from the solar system after all.
一种情况是把东西从太阳系里
One type of ejection is where you just take something
完全扔了出去
and you throw it out of the solar system,
但另一种更温和的情况是
but another more gentle kind
没有完全把它扔出去
is when you don't quite make it all the way out,
而是在一个非常非常长的周期内
and instead you go on a very, very long period orbit
围绕着年轻的太阳系运行
around the young solar system.
第九颗行星被认为是非常遥远的行星
Planet nine is thought to be so far out,
它绕太阳公转需要2万年的时间
it takes up to 20,000 years for it to travel around the Sun.
也许它一直在观察着太阳系
Perhaps it's been observing the dramatic,
在其2万年的寒冷轨道上
dynamical evolution of the solar system
戏剧性的动态演化
unfold from its frigid 20,000-year orbit.
无论第九大行星是否是失散已久的兄弟行星
Whether planet nine is a long-lost sibling or not,
冰巨星在驯服木星方面发挥了巨大的作用
ice giants played a huge role in taming Jupiter.
他们使我们的太阳系成为今天的避难所
They made our solar system the haven it is today.
但冰巨星不是和平的地方
不知为何，在寒冷的海王星上
狂野的天气、神秘的超级风暴
甚至钻石雨都在折磨着它
But they are not peaceful places.
Somehow, out in the deep freeze,
Neptune is tormented by wild weather,
mysterious superstorms and maybe even diamond rain.
天王星和海王星……
Uranus and Neptune...
它们位于我们太阳系的边缘
Their location at the edge of our solar system
这使得它们很难研究
makes them very difficult to study.
冰巨星天王星和海王星
The ice giants Uranus and Neptune
对我们来说非常神秘
are very mysterious to us.
它们非常遥远，所以很难用
They're very far away, so they're hard to observe
地球上的望远镜观察到
with telescopes here at the Earth.
导致
As a result,
这些行星长♥期♥以来一直被忽视
these planets have long been overlooked.
我们唯一一次近距离看到这些遥远的庞然大物
The only time we've glimpsed these distant giants up close
是在20世纪80年代旅行者2号♥ 飞过它们的时候
was when voyager 2 flew past them in the 1980s.
这个结果让海迪·哈梅尔(Heidi Hammel)感到惊讶，她是
The results amazed Heidi Hammel, part of the voyager 2
旅行者2号♥飞掠海王星时的成像小组的一员
imaging team at the time of the Neptune flyby.
关于飞掠行星，最奇妙和最令人沮丧的
One of the most wondrous and frustrating things
事情之一是，你学到的东西太多了
about planetary flybys is that you learn so much
以至于你打开了一个装满问题的潘多拉盒子
that you open a whole Pandora's box of questions.
有一项观察立即引起了科学家们的兴趣
One observation instantly intrigued scientists.
海王星拥有太阳系中最快的风
Neptune has the fastest winds in the solar system.
在地球上，我们的风实际上
Here on Earth, our winds are actually driven
是由不同的温度和阳光驱动的
by different temperatures from sunshine.
海王星离太阳太远了
Neptune is so far away from the Sun
它几乎没有从我们的母恒星接收到任何能量
that it receives almost no energy from our star.
海王星距离太阳30亿英里
Neptune is 3 billion miles from the Sun.
那里真的很冷，为什么会有这么快的风？
It's really cold there, so why does it have such fast winds?
一颗行星从太阳接收到的能量越少
The less energy a planet receives from the Sun,
我们预计它的天气就会越安静……
the quieter we expect its weather to be...
但海王星一点也不平静
But Neptune isn't tranquil at all.
它被猛烈的暴风雨所覆盖
It's covered in massive violent storms.
有些风暴的大小堪比内行星
There are storms that are rivaling
那是一场相当大的风暴
the size of the inner planets.
有记录以来
That's a pretty big storm.
海王星上最大的风暴之一
One of the largest ever recorded on Neptune
是1989年的大黑点
is known as the 1989 great dark spot,
那是一场巨大的风暴
a single vast tempest,
大到足以吞没整个地球
large enough to swallow the Earth whole,
以每小时1500英里的惊人速度
riding on a jet stream with a mind-blowing wind speed
飞驰着
of 1,500 miles per hour.
毫无疑问，海王星保持着
Hands down, Neptune holds the record
太阳系中最快风速的记录
for the fastest wind speeds in the solar system.
地球上最快的龙♥卷♥风♥风速
The fastest tornado winds on Earth
只有几百英里每小时
are only a few hundred miles an hour,
但这已经造成了毁灭性的破坏
and that does devastating destruction,
所以很难想象海王星上的风会有什么影响
so it's hard to imagine what winds on Neptune would do.
进入海王星上层大气的探测器
A probe entering Neptune's upper atmosphere
将会记录下零下370华氏度的(约零下224摄氏度)
would record freezing temperatures,
冰冻温度……
minus-370 degrees Fahrenheit...
我以为这么冷，吹不出风来
Too cold to generate the wind we see.
然而，在600英里深处，探测器
600 miles down, though, the probe is smashed
被海王星无情的喷射气流给粉碎了
by Neptune's relentless jet stream winds.
往下潜得越深，温度就越高
And the deeper you go, the warmer it becomes.
海王星内部产生的热量
Neptune has almost three times
几乎是来自海王星表面
as much heat coming from its interior
气体球所产生的热量的
than you would expect from a ball of gas
三倍
out at Neptune's distance.
奇怪的是，这些高速海王星的风
The strange thing about these high-speed Neptune winds
并不是由太阳的热能驱动的
is that they're not powered by heat energy from the Sun.
事实上，它们是由海王星内部的
In fact, they're powered by heat energy
热能提供能量的
from Neptune's own interior.
那么这些内部热量是从哪里来的呢？
So where does this internal heat come from?
当行星形成时,这是一个非常暴♥力♥,能量非常充沛的事件
When planets form, it's a very violent, very energetic event,
此时行星是非常热的
and the planets are actually extremely hot,
需要数十亿年的时间才会将热量释放掉
and it takes billions of years for that heat to leak away,
所以使得海王星
so Neptune, it turns out,
可能仍有大量的热量
probably still has a tremendous amount of that heat
被困里面，当热量像泡沫一样冒出来时
that is trapped inside of it, and as that bubbles up,
这就是使大气变热并最终导致
that's what's actually heating the atmosphere
这种恶劣天气的产生
and driving this tremendous weather.
那么海王星是如何保留这么多热量的呢？
So how does Neptune retain so much heat?
这个秘密深藏在大气层之下
The secret lies deep below the atmosphere.
当你一直往下、往下、往下
As you go down and down and down,
你会发现压力越来越大
you'll just find the pressure gets more and more intense
直到你最终被压扁
until you are eventually essentially crushed.
大气层会变得越来越厚，像雾一样
That atmosphere will get thicker and thicker like a fog
直到你突然意识到，你是在海洋里
until suddenly you would realize that instead of an atmosphere,
而不是大气层
you are in an ocean.
海王星有一个由甲烷、氨和水
Neptune has a super-dense fluid mantle
组成的高密度流体地幔
made up of methane, ammonia, and water.
事实上，冰巨行星并不是固态的冰球
Really, an ice giant is not a solid ball of ice,
而是由旋转的液体物质组成的移♥动♥海洋
but rather a moving ocean of swirling liquid material.
这种旋转的液体会留住热量
This swirling liquid traps the heat,
就像毯子一样把核心隔离起来
acting like a blanket, insulating the core.
这就是海王星恶劣天气的秘密
This is the secret to Neptune's wild weather,
而海王星富含甲烷的地幔中
and the intense interior heat
强烈的内部热和压力可能会
and pressure in Neptune's methane-rich mantle
产生另一个不同寻常的影响
may create another extraordinary effect.
压力非常强烈
The pressure is so intense