宇宙（2007）

The Universe S01E08

Part 1 April 22, 2021, 8:12 p.m.

It is the show-stopperof our Solar System,
这是太阳系的明星秀
basking in its own glow,it seduces all admirers.
闪亮的外表吸引着大量的爱好者
However, it is a beautywith a mean streak.
但是,美丽外表下隐藏着恶魔
It's a massive, frigidball of gas,
土星是一个环绕着冰质光环的气态星球
surrounded by icy ringshurdling at 40,000 miles an hour.
光环以40000英里每小时[6♥4♥000千米每小时]旋转
It is a planet of violent weather,
土星有着非常疯狂的气象
with a polar storm biggerthan the United States of America.
极地的飓风面♥积♥比美国还大
Saturn has some of the mostpowerful weather in the Solar System.
土星的一些气象是太阳系中最强大的
The lightning could be a million timesmore powerful than here on Earth.
闪电的能量比地球上的大100万倍
But its moons are evenmore exciting.
不过土星的卫星更吸引人
The geysers on Enceladusare erupting water vapour
Enceladus[土卫二]上的喷泉喷出几百英里高的水汽
hundreds of miles into the air
because there's muchlower gravity there
因为这里引力很小,且没有大气
and the fact that there'sno atmosphere holding them in.
Another has an atmospherewith oceans and mountains.
另外一颗土星卫星有大气,海洋和山脉
Could life exist on one of these moons?
也许某颗卫星上会有生命
Saturn, Lord of the Rings.
土星----光环王者
土星——光环王者
If there is one planet
如果说宇宙中有一颗行星
that represents the majesty,mystery and awe of the Universe,
象征着美丽,神秘和奇异
it is Saturn.
那一定是土星
It stirs emotioneven from scientists
科学家们也为之激动
who are stunnedby its cosmic perfection.
被这完美宇宙奇观惊动
You've got to hand it to Saturn forbeing the most beautiful thing out there.
你不可否认土星是这宇宙中最美丽的
It's been my favourite planet sinceI first saw it through the telescope.
土星是我最喜欢的行星我一直用望远镜观察它
While it looks sleepy and serene,
尽管看起来宁静安详
the sixth planet from the Sunis anything but.
这颗太阳系第6行星其实并不平静
Saturn is a dynamo whosebeauty is skin-deep.
美丽的外表下隐藏了一个发电机的心
Saturn's an absolutelyfrigid place.
土星上极其寒冷
You wouldn't want to stepout on the surface. For one reason,
不要想着登陆土星
you'd fall 'causethere is no surface,
首先,没有固体表面
but secondly, you'dfreeze to death instantly.
其次也会立即冻死
Saturn is a hunk of hydrogenand helium
土星是一个大量氢气和氦气
that races around its axisdistorting its shape.
围绕自轴高速旋转成型的行星
When you watch a professionaltoss of pizza,
观察专业意大利比萨制♥作♥过程
as it spins aroundit flattens out.
手抛饼底,旋转扁平成型
So it's the same kind of idea,because it's spinning so rapidly
同样的道理,由于很高的旋转
it's actually sort of squashed,sort of bulges in the middle.
土星有一点扁平,中间鼓起来
It's called an"oblate spheroid".
称之为"扁球"
Even though it's much moremassive than our own planet,
尽管体型比地球大很多
you'd actually weigh slightly lesson Saturn that you do on Earth.
土星上的重力比地球还略小
A 150-pound human would weighonly 137 pounds on Saturn.
一个150磅[68kg]的人,在土星上只有137磅[62kg]
That's because Saturn hassuch a low density.
是因为土星密度很低
The only planet in the Solar Systemless dense than water.
是太阳系中唯一密度低于水的行星
Saturn is so bloated,the gases
土星如此臃肿
take up so much spacecompared to the total amount of mass
绝大部分体积都是气体
in Saturn, that its densityis less than one.
于是密度低于水
So if we could getsomehow some...
因此,假如我们有一个巨大的海
really big ocean in put Saturn in it,it would float.
把土星放进去,它会飘浮着
Saturn is the second largest planetin our Solar System.
体型上,土星是太阳系第二大行星
It is a gas giant,
是个气体的巨行星
a mass of hydrogen and helium
大量的氢和氦
750 times the size of Earth.
有地球750倍大
A day on the planet is10,6 hours long.
一天只有10.6个小时
And it takes 29.5 Earth yearsto orbit the Sun.
绕太阳一周需要29.5个地球年
It has 48 named moons.
拥有48个已命名的卫星
Saturn has been aroundfor 4.5 billion years.
土星存在于太阳系几乎45亿年了
It formed by accreting carbon dust,particle by particle,
硬质核心由碳颗粒积聚而成
into a rocky core several timesthe size of Earth.
大约有几个地球大
Then, it was able to attract gases,like hydrogen and helium,
吸引着外面大量的氢和氦
which collapsed under gravity.
巨大重力下这些气体坍塌了
As things started collapsing,this cloud began to compress,
由于开始坍塌,气体被压缩
it began rotatingmore rapidly,
旋转也变的更快
but along its axis, from let's saytop to bottom, it wasn't rotating,
沿自转轴方向上,顶部到底部是不旋转的
so it was free to collapseunder the force of gravity.
因此,重力作用下自行坍塌了
It's called the conservationof angular momentum.
角动量守恒定理
A principle on display at yourlocal ice ring.
最初在溜冰场上被展示
If you push your arms out if you'rean ice skater, you'll go more slowly.
如果你伸开你的腿和双臂速度会变慢
If you pull your arms in,then you'll be
收紧你的双臂
more concentrated towardsthe axis of rotation
靠近你的旋转轴
and you'll haveto spin faster.
你会转的更快
And that's just what happens fora planet as it condenses.
行星在收缩时也会这样
A spinning Saturn came outof this collapsed disk.
土星在圆盘坍塌过程中旋转起来
The feature that has made Saturn themost iconic planet in our Solar System,
土星是太阳系中
最壮丽的标志
is its majestic, shimmering rings.
拥有明亮的光环
They are incredibly big,173,000 miles in diameter.
光环不可思议的大直径约170000英里[280000km]
Wider than 21 Earthsside by side.
比21个地球排列还宽
So it would take you 2 daysin a really fast rocket ship
巨大的光环高速旋转
to get from one side of the ringsto the other. They're huge.
从一端到另一端只需约2天
However, these huge rings alsoare unbelievably thin.
但是这些巨大的光环不可思议的薄
Measuring about 65 feet.
只有65英尺[20米]厚
When viewed from the side,they virtually disappear.
如果从旁边观看几乎看不到
They are no thickerthan about one,
厚度大约只相当于
maybe two storeysin a modern day building.
两层楼高
They're paper-thin in comparison.
就像一张纸
The rings may look likeperfect solid disks,
看起来像个完美的固体圆盘
however, they are actually made upof billions of pieces of space debris.
实际上,却是由无数碎片
散布而构成
But what exactly are they?
多大的碎片?
They are countless icy bodies,ranging in size from...
这些大量的冰冷碎片
objects as big as houses allthe way down to the finest,
大的相当于房♥屋大
powdery snow, you mightski on in Utah.
小的仅有犹他州滑雪场的雪花那么大
And they're made ofwater ice.
都由冰块组成
They're particles thathave been pulverized,
碎片散布又互相碰撞
so they've smashed into each other,
they've broken up into many, manylittle particles.
碎成更小的颗粒
If you were to be inside those ringsit would be like a beehive.
呆在土星环里,你会被击成蜂窝
They're all over the place,like bees in a swarm.
到处都是密布的蜂群
It's a hostile place,
不要派飞船到危险的土星环上去
you do not want to try to put aspacecraft through those rings.
And these particlesspin very fast.
这些碎片高速旋转
And they're screaming around the planetat 20 to 40,000 mph.
旋转速度大约20000至40000英里每小时[32000至6♥4♥000千米每小时]
The inner rings spin fasterthan the outer rings,
环内部比环外部的速度快的多
and there's a reason for that.
原因是
Kepler's laws say
开普勒定理表明
that if you're gonna orbit in a circlearound a central body,
如果以圆形轨道环绕中心旋转
if you're close up you move really fast,if you're far away, you move really slow.
越靠近中心旋转越快越远离中心旋转越慢
If a particle the sizeof a grain of sand
如果一颗细沙大小颗粒
moving at hypersonic speedwere to strike a spacecraft,
以超音速击中太空船
it would be like a shotgun blastat point blank range.
不亚于一枪击中太空船
And you get outside the rings,
环外的空间
things are much quieter.
相当宁静
If you want to take a country drivearound Saturn, go this way,
如果去参观土星
instead of following the rings.
请绕过土星环,不要接触它
Why the rings are thereis one of the planet's great mysteries.
为什么说环是土星最神秘之处呢?
The rings might have once beensome of Saturn's moons
环在很久以前可能是两颗很近卫星
that got too closeand smashed into each other.
碰撞并碎裂了
The fractured pieces were heldby the planet's gravity
土星的引力维持着这些碎片
to become its rings.
形成土星环
According to another theory,
基于另外一个理论
something big and fastmight have crashed
也许一个巨大的高速物体
into one of Saturn's many moons.
撞击了某个土星卫星
The broken shards were suckedin by gravity
碎片被土星引力留下
and fell into orbitforming the rings.
旋转而形成土星环
Although scientists disagreeas to how the rings were formed,
尽管科学家们对环的形成意见不那么统一
they do agree as towho first studied them.
对土星环的发现者却没有异议
In 1610, the Florentineastronomer Galileo Galilei,
1610年,天文学家伽利略
first noted the ringsof Saturn.
第一个观测到土星的光环
He saw these little thingssticking out on the side
他看到这些固定在土星周围的光亮物质
of the planet. He had no idea whatthey were, so like any good astronomer,
不知道是什么东西像很多天文学家那样
Galileo kept a journal, and he wanted towrite into his journal what he had seen,
伽利略记录了他的发现
but he didn't have a word for it, soin his journal, right in with the words,
但是,没有具体说明
因此他的笔记里没有任何词语说明