了解宇宙是如何运行的（2010）

How the Universe Works S06E02

Part 6 Dec. 22, 2021, 7:22 p.m.

只是现在它们不再显示出任何存在的痕迹
They no longer show any trace of their existence...
所以如果我们再等一会儿
So if we waited around a little bit longer
直到所有的阿胡娜·蒙斯火山
until all of Ahuna Mons had slowly relaxed
都慢慢地回到这个星球地表上
那么我们也同样看不到它的踪迹
back into the planet, we'd see no trace of it, either.
也许阿胡娜·蒙斯并不总是孤立无援
Maybe Ahuna Mons hasn't always stood alone.
也许这只是最后一次了
Maybe it's just the last of its kind.
这个谜团只是围绕矮行星的众多谜团中的一个
Ceres continues to confound our expectations,
还有许多与其他矮行星♥相♥关的谜团
and there are still many mysteries
有待我们去解决
with the other dwarf planets to be solved,
例如他们如何是得到卫星的
such as how they got their moons
以及冥王星为什么侧躺着旋转
and why Pluto lies on its side.
就像它们的大表兄弟一样
Just like their larger cousins,
矮行星通常有轨道卫星
dwarf planets often have orbiting satellites.
我们发现所有最大的矮行星
We now realize that all of the largest dwarf planets
都有卫星环绕在它周围
have moons around them, have a moon.
大多数都只有一个。妊神星有两个
Most of them have one. Haumea has two.
冥王星有五个
Pluto has five.
40亿年前
Four billion years ago,
年轻的太阳系一片混乱
the young solar system was chaotic,
到处都是围绕太阳运转的小天体
filled with small bodies orbiting the Sun.
其中一颗撞击了刚刚形成的地球，形成了月球
One hit the infant earth, forming the moon.
这样的碰撞在整个太阳系都发生过
Smash-ups like these happened throughout the solar system.
矮行星妊神星
The dwarf planet Haumea formed from an explosive collision
是由两个较大的天体之间的爆♥炸♥碰撞形成的
between two larger objects...
这可能就是它不寻常的豆状形状的原因
Which may account for its unusual bean-like shape.
所有的矮行星都遭受了巨大的冲击
All the dwarf planets suffered huge impacts.
妊神星有个大家伙让它旋转
Haumea had this big one that left it spinning.
阋神星有一个很小的月亮，大概是因为巨大的撞击形成的
Eris has a tiny moon, presumably from a giant impact.
鸟神星有一个卫星
Makemake has one.
所有这些最大的天体都有这些微小的卫星碎片
All these biggest objects have these tiny fragments of moons
这向我们展示了在历史上它们曾经
showing us their history of just getting battered
遭受过撞击，碎片撞得到处都是
and pieces being knocked off everywhere.
大多数矮行星的卫星都很小
Most dwarf planets' moons are tiny,
不会比小行星大多少
not much bigger than asteroids,
但有一个卫星却大不相同
but one moon is very different...
就是冥王星的卫星——卡戎
Pluto's moon, Charon.
冥王星的卫星可以说比冥王星还古怪
Pluto's moon is, if anything, weirder than Pluto itself.
和弗兰肯斯坦科学怪人一样古怪
It's Frankenstein's moon.
好像有人把卫星撕成了两片
It looks like somebody tore a moon apart
然后又把它们拍打在一起
and then just kind of slapdashed it back together.
它的一个半球是光滑的
One hemisphere is smooth.
另一个则非常崎岖
One is very rugged.
它有一个峡谷，就像凿刻在星球边上的凹痕
It's got a canyon that's like a notched carved out of the side.
真的很奇怪
It is really bizarre.
可能是一次撞击形成了卡戎
An impact may have formed Charon
并使它与冥王星
and left it tied to Pluto
以一种奇怪的相互依赖的关系联♥系♥在一起
in an oddly codependent relationship.
在某些方面
In some ways, you can think of
你可以认为冥王星-卡戎几乎是一个双行星系统
the Pluto-Charon system as almost a binary planet.
在太阳系中没有其他行星的卫星
There is no other planet in the solar system
与主星♥相♥比，比例如此之大，以及如此之近
where the moon is so large in proportion to it and so close.
和其他双星一样
Like other binary objects,
冥王星和卡戎围绕一个中心引力点运行
Pluto and Charon orbit around a central gravitational point.
冥王星和卡戎被困在这场引力舞蹈中
Locked in this gravitational dance,
他们总是面面相觑
Pluto and Charon always show each other the same face.
冥王星和卡戎最有趣的一点
One of the really interesting things about Pluto and Charon
它们处于我们所说的潮汐锁定状态
is that they're what we call tidally locked.
当冥王星和卡戎形成的时候
When Pluto and Charon formed,
它们可能都在各自的自转轴上旋转
they were probably both rotating on their own axes,
但这两个星球的自转速度逐渐减慢
but the two worlds actually slowed down their rotation
并最终锁在了一起
and locked together,
在公转过程中一直用同一面对着彼此
with one side constantly facing the other as they orbit around.
但是冥王星的自转是反的
But Pluto's rotation is tipped over
就像一个陀螺侧躺着旋转
like a top spinning on its side,
所以卡戎围绕冥王星的轨道也是反的
so Charon's orbit around Pluto is also tipped over.
太阳系中几乎每一颗行星
Almost every planet in the solar system has an orbital axis
都有一个大致指向同一方向的轨道轴
that points in roughly the same direction.
而冥王星却倾斜了大约120度
Pluto's is tilted down about 120 degrees.
长♥期♥以来，科学家们一直想知道
Scientists have long wondered
是什么导致了这种差异
what caused this disparity.
卡戎把冥王星拉过来了吗？
Did Charon pull Pluto over?
或者说倾斜是由形成卡戎的撞击造成的？
Or is the tilt a result of the impact that formed Charon?
当“新视野”发回冥王星爱心的图像时
A clue was revealed when new horizons
一个证据被揭示了出来
sent back images of Pluto's heart.
当“新地平线”号♥探测器接近冥王星时
One of the more endearing features of Pluto
发现冥王星的一个很可爱的特征
as the new horizon's probe approached it
冥王星面向航♥天♥器一侧
was a gigantic heart-shaped region
有一个巨大的心形区域
on the side of Pluto facing the spacecraft.
斯普特尼克平原
Sputnik Planitia, a bright, white heart
在冥王星暗斑驳的表面上有一颗明亮的，白色的心
against Pluto's dark, pockmarked surface.
当我们拍到这张特写时，真是太吸引人了
When we got closeups of this, it was completely fascinating.
我当时大声地喘着气
I gasped out loud.
这是多么令人震惊，我记得我说过
This is how shocking this was, and I remember saying,
“哦，天哪。那里没有撞击坑！”
"oh, my gosh. There are no craters there!"
它很光滑，就像湖面上结冰一样
It is smooth, like it's a frozen-over lake.
说明有一种液态物质
This is indicative of something liquid,
在冥王星表面下流动
something flowing under the surface of Pluto,
我们看到的是冥王星的顶部冰冻层
and what we're seeing is the top, frozen layer of it.
甚至还有对流区域
There are even convection cells
那里的冰似乎正在变暖和扩散
where the ice appears to be warming and spreading out.
这表明，在冰下，有一个能量来源
That suggests that underneath, there's a source of energy,
令人惊讶的是，冰下甚至可能有一个巨大的
and amazingly, there may even be a huge basin of liquid water
液态水盆地
under that ice.
斯普特尼克平原可能隐藏着
Sputnik Planitia may hide a giant,
巨大的地下液态水海洋
subterranean ocean of liquid water.
它也是冥王星表面的一个巨大伤疤
It's also a gigantic scar on Pluto's surface.
考虑到形状和大小
Most likely, given the shape and size,
斯普特尼克平原最有可能是在巨大的撞击中形成的
Sputnik Planitia was formed in a giant impact.
有东西撞到冥王星了
Something smacked into Pluto.
地下水和撞击的结合
Could the combination of subsurface water
能解释冥王星异常倾斜的原因吗？
and an impact account for Pluto's unusual tilt?
有一种理论认为
One theory suggests that an object
一个物体撞到冥王星的顶部
smashed into the top of Pluto.
撞击震碎了地表
The impact shattered the surface,
水渗出并填满了陨石坑
and water oozed up to fill the crater.
液态水使冥王星失去平衡
The liquid water knocked Pluto off balance,
而与卡戎的引力舞蹈
and the gravitational dance with Charon
将这颗沉重的心旋转到了另一边
spun this heavy heart out to the opposite side.
其中一个想法是，斯普特尼克平原之所以在原地形成
One idea is that Sputnik Planitia formed where it is
是因为冰可以在一个巨大的撞击坑的底部积累
because ices can accumulate in the floor
于是形成的现在这个样子
of a giant impact base.
但目前还不确定这是不是真的
But it's not yet certain whether that's actually the case or not.
曾经被认为是死气沉沉的小块头矮行星
Dwarf planets, once thought to be dead lumps,
现在充满了神秘
have come alive with mysteries.
他们挑战了我们所有的假设
They've challenged all our assumptions,
然而，我们仅仅触及了
and yet, we've barely scratched the surface
这些复杂世界的表面
of these perplexing worlds.
还有更多的矮行星有待发现
There are many more dwarf planets to discover,
谁知道它们还会带来什么惊喜呢？
and who knows what surprises they may have in store?
我们不知道矮行星的最终数目
We don't know the final count of dwarf planets
因为我们仍在寻找它们
because we're still finding them,
但我认为在冥王星附近
but I think that there are probably somewhere
可能有100到200颗矮行星
between 100 and 200 dwarf planets out past Pluto.
在太阳系更远的地方
There are probably many, many more as you go
可能会有更多
even further out in the solar system.
矮行星可能是我们在太阳系中
Dwarf planets are, perhaps, the most interesting objects
发现的最有趣的天体
we've found in the solar system.
他们非常多样化，他们有活动的地质
They're diverse. They're geologically active.
它们还含有液态水
They contain liquid water.
尽管它们个头都很小