了解宇宙是如何运行的（2010）

How the Universe Works S01E08

Part 5 April 18, 2021, 7:58 p.m.

只在地球15,000英里之外运行
the moon orbited just 15,000
miles above the Earth's surface.
月球形成后5亿年
500 million years after the moon formed,
如果我们抬头仰望
if we looked up, in the sky,
会见到月球雄据大部分天空
the moon would have comprised
a tremendous portion of the sky,
因为月球很贴近地球
it would have been enormous
所以看起来巨大无比
because the moon would
have been much closer.
当时地球转得快, 一天只有6小时
Back then, the Earth was rotating
so fast, a day lasted just six hours.
但月球近在眼前, 引力有煞停作用
But the moon was so close,
its gravity acted like a brake.
直至一天变成24小时
until a day now lasts 24 hours.
月球引力亦导致地球潮水暴涨
The moon's gravity also created giant
tides that surged across the planet
海水翻腾, 矿物质和养份混合起来
churning up the seas, mixing
minerals and nutrients.
形成原生浆液, 生命由此诞生
This created the primordial soup from
which the first forms of life arose.
没有月球, 地球可能永远没有生命
Without our moon, life on
Earth may never have happened.
其它卫星亦可能和生命有关连
And there may be other moons
with a link to life as well.
卫星可能是宇宙的伟大生物实验
Moons may be the great biology
experiments of the universe,
生命的真正实验室
the true laboratories of life itself.
卫星充满惊喜
Moons are full of surprises.
有些卫星有大火山
There are moons with giant volcanoes,
有些卫星有大海, 藏在厚厚冰层下
moons with vast oceans
sealed under thick ice.
现在又知道有一些布满有机复合物
And now we know a few are
rich in organic compounds.
如果配合得宜, 甚至可能长出生物
In the right combination,
they might even support life.
在我们的太阳系
In our solar system,
想了解宇宙其它地方的奥秘
the biological window through which we
can understand the rest of the universe
或者要透过外太阳系的卫星去研究
may be through these moons
of the outer solar system.
可能从中找到第二部创世记
That may be where we
find our second genesis,
第二部创世记让我们真正明白
and that second genesis is really
our first deep understanding
宇宙的生物本质
of the biological
nature of the universe.
乍看起来, 卫星不似适宜生物居住
At first glance, moons
don't look ideal for life.
例如土卫二
Take Enceladus.
它是个宽300英里的闪亮冰球
It's a shiny ball of
ice, 300 miles across,
环绕土星运行
orbiting Saturn.
它是太阳系中最光亮的物体
It's the brightest object
in the solar system.
射来的光都百分百给它反射出去
It reflects a hundred percent
of the light that hits it
因为表面是水冰, 所以亮度超高
So it's super bright, and
that's because it's water ice.
2005年卡西尼号♥发现…
In 2005, the Cassini
probe spotted ice volcanoes
土卫二的冰♥火♥山爆发
erupting from the surface on Enceladus.
显示冰下一定有热力
That meant there had to
be heat under all that ice,
热力产生大量的水
heat that created oceans of water.
而有水的地方就可能有生命
And where there's water,
there's the possibility of life.
这是黄石公园的蜂窝间歇泉
So this is Beehive Geyser
here in Yellowstone,
把水蒸气和水射上约150英尺高空
and it is shooting water vapour and
water about 150 feet into the sky.
相当壮观
And it's pretty incredible.
现在请想象自己站在土卫二之上
So now imagine if you're
on the surface of Enceladus,
你会见到类似的间歇泉
you would see geysers that
look a lot like this...
把冰粒和水蒸气喷入太空
and they are shooting ice grains
and water vapour into space,
比这个间歇泉高出数千倍
thousands of times higher
than this geyser here.
冰♥火♥山的动力来自引力
The ice volcanoes are
powered by gravity.
运作原理如下
Here's how it works.
土星的引力使卫星核心发热
Saturn's gravity works on the
core of the moon, heating it up.
地底的水膨胀
The underground water expands
逼上表面冰层的隙缝
and forces its way up through
cracks in the surface ice
以冰晶形态射入太空
and blasts out into
space as ice crystals.
造就了太阳系中最壮观的大爆发
These are some of the most spectacular
eruptions in our solar system.
相形之下, 蜂窝间歇泉像一支水枪
They make Beehive Geyser
look like a squirt gun.
科学家从火山的冰…
From the ice in the volcanoes,
找到盐和简单的有机复合物
scientists have detected salt
and simple organic compounds.
显示冰下的水既温暖, 又富有养份
That means the water under the ice is
not only warm but full of nutrients.
是否很熟悉?
Sound familiar?
热力、水和养份
Heat, water and nutrients,
地球生命就是由此诞生
that's how life on Earth began.
原来地球海洋有的一切
We realise you could have all the things
that we associate with oceans on the Earth
都存在于卫星
going on inside a moon.
真是个难得的大发现
It's the discovery of a lifetime.
土星的土卫二有海洋
Saturn's Enceladus has an ocean,
木星的木卫二也有
so does Jupiter's Europa.
但不只它们可能长出生命
But these aren't the only
moons where life could emerge.
土星有另一颗卫星
Saturn has another moon,
土卫六长出生命的潜力更大
Titan, with an even
greater potential for life.
2005年卡西尼号♥派出惠更斯号♥
In 2005, Cassini sent
a probe called Huygens
往土卫六执行一个单程式任务
on a one-way mission to Titan.
全程历时仅3.5小时
For just three and a half hours,
惠更斯号♥从接近十亿英里外的星球
Huygens transmitted live pictures
from the hostile surface...
实地传来图片
nearly a billion miles away.
然后电池便用罄
Then the battery died.
真的了不起
It was just incredible.
人类透过自己发明的工具
This was the first time humans
had ever touched this moon
首次触摸这颗卫星
with something of our own making.
是值得全球庆祝的大事
It was just an event that should
have been celebrated the world over.
我们应该在欧美各大城市
We should have had ticker-tape parades
举办巡游
in every major city
across the US and Europe
作为庆祝
to celebrate this.
这是开创先河、值得惊叹的大事
It was that history-making
and that astonishing.
土卫六的雨点是地球的两倍
Raindrops on Titan are twice
as big as raindrops on Earth.
但雨点不是水, 而是甲烷
But the rain isn't water, it's methane.
在地球, 甲烷是气体
On Earth, methane is a gas,
但因为土卫六很冷, 甲烷呈液态
but on Titan, it's a liquid
because the moon is so cold.
可能有甲烷冰山
There may be methane icebergs,
肯定有甲烷湖和河
there's certainly
methane lakes and rivers
有甲烷雨和甲烷云
and there's methane
rain and methane clouds,
可能有昆虫浮游于甲烷内
and maybe bugs swimming in methane.
昆虫活在液态甲烷, 似是天方夜谭
Bugs living in liquid methane
may sound unbelievable.
但科学家发现…
But scientists have discovered
土卫二、木卫二和土卫六
that Enceladus, Europa and Titan
都有种名为托林的物质
are all covered with a
substance called tholin.
托林含有生命必需的化学材料
Tholin contains the chemical
building blocks for life to begin.
那么这些卫星是否有机会有生命?
So could life emerge on
any or all of these moons?
我们无法从卫星取得托林
We can't get our hands on
the tholin from the moons,
所以基思麦卡在实验室仿制
so Chris McKay makes it in the lab.
他电击从土卫六发现的混合气体
He zaps a mixture of gasses
found on Titan with electricity.
得到的结果是一堆红褐色泥土
What he gets is a reddish brown mud.