宇宙（2007）

But closer to the Sun,
但是离太阳越近
planetary fields are mysteriously less common.
行星的磁场就越弱 令人费解
Mercury has a very weak magnetosphere, about 1% of Earth's.
水星的磁层很弱 大约是地球的百分之一
Venus has virtually none.
金星则根本没有磁层
And the most mysterious of all is the red planet, Mars.
最神秘的是那个红色的星球 火星
In the late nineties, the Mars Global Surveyor spacecraft,
九十年代末 火星环球探测者飞船
which was in orbit around Mars,
它的轨道就围绕着火星
had a magnetometer aboard.
飞船上有一个磁力计
That magnetometer found
磁力计发现
that Mars does not have a global magnetic field.
火星没有一个球形的磁场
But the Mars surveyor found evidence of
但是火星探测者发现
small magnetic Fields scattered on the face of the planet.
火星表面散布着小磁场
NASA believed it was paleomagnetism,
NASA认为那是古地磁
an ancient remnant from a period billions of years ago.
即数十亿年前留下的古代残迹
Did Mars once have a magnetic field rivaling Earth's?
火星曾经有过跟地球一样的磁场吗
And if so, what happened to it?
如果是 那它怎么样了
Fortunately, we don't have to go to the red planet to investigate,
我们很幸运 不必去那颗红色的星球调查
because pieces of the red planet are already here.
因为它的碎片已经在这里了
We actually have samples, rocks from Mars.
我们的确有样品 来自火星的岩石
They're meteorites.
是陨石
They were blasted off of Mars
由于数百万年前
by an asteroid or comet impact millions of years ago.
一次小行星或彗星的撞击 它们从火星飞了出来
These rocks wandered around in space,
这些岩石在宇宙中游荡
And then some of them landed on the Earth randomly.
其中一些偶然地落到了地球上
One of these martian meteorites is actually famous:
这些火星陨石中有一块真的很有名
Some scientists have suggested
一些科学家已经表明
it contains the remains of ancient martian life-forms.
它含有古代火星生命的残骸
Whether or not this proves true,
不管这一点能否证实
this piece of rock may answer the question of Martian magnetism.
这块岩石也许可以回答关于火星磁力的问题
ALH 84-001 is the oldest known rock from any planet
ALH84-001是已知来自所有行星中最老的岩石
and it is a unique sample from Mars.
它是来自火星的唯一样本
It lived through the earliest epoch of Martian history.
它经历了最早的火星历史纪♥元♥
So this sample has all kinds of fascinating records in it.
所以它里面有各种令人着迷的印记
MIT's superconducting quantum microscope, or "Squid,"
麻省理工学院的超导量子显微镜 也叫乌贼
is one of the most sensitive magnetic detection devices on Earth.
是地球上最灵敏的磁力探测器之一
A sample from the Martian meteorite
一个来自于火星陨石的样本
gives up startling results under the squid lens.
在乌贼的镜头下交出了令人吃惊的结果
We showed that this rock is magnetized and the magnetism,
我们发现这块岩石是磁化的
the paleomagnetism has been very precisely dated
这个古地磁可以精确地追溯
to be about four billion years old.
到大约40亿年前
Beneath the surface of the meteorite
这块陨石表面之下
is the ancient record of Mars' magnetosphere.
是古老的火星磁层的记录
Four billion years ago, a strong magnetic field
40亿年前 火星内核中搅动的岩浆
was generated by churning magma in the planet's core.
产生了一个强大的磁场
Early magnetic Mars was
早期的有地磁的火星
a fundamentally different place than the one we see today.
跟我们现在看到的完全不同
The atmosphere we think at that time
我们认为当时的大气层
was much thicker than it is today.
比现在的厚得多
There was probably water flowing on the surface.
也许表面还有水流
Temperatures were warmer.
气候温暖
So it was much more Earth-like.
所以比现在更像地球
Then, mysteriously, Mars died.
后来不知为什么 火星死了
Temperatures dropped. Water vanished.
温度下降 水也干了
The atmosphere disappeared. What happened?
大气层消失了 发生了什么呢
Mars' magnetic field died sometime around 4.1 billion years ago.
火星的磁场在大约41亿年前消失了
What's really fascinating about that is
真正令人着迷的是
it seems to be roughly coincident with the time when Mars began to change
磁场的消失跟火星开始发生变化基本是同时发生的
from an early warm, wet state
从早期温暖湿润的状态
to its current cold and dry conditions.
变成现在寒冷干燥的情况
One hypothesis for why Mars' atmosphere disappeared
对于火星大气层的消失有种假设
is because it didn't have a magnetosphere to help protect it.
就是因为它没有了磁层的保护
So the solar wind was constantly stripping away
所以来自太阳的离子流不断地
parts of the Mars atmosphere.
侵蚀火星大气层
Without magnetic armor,
没有了磁力盔甲
a coronal mass ejection would bombard Mars' surface,
日冕物质抛射会轰炸火星的表面
A magnetic hurricane that would tear away the planet's atmosphere.
磁力飓风也会撕开它的大气层
Suddenly, the atmosphere was losing large quantities of gases
大气层突然失去大量的气体
like oxygen, argon, nitrogen.
比如氧气 氩气 氮气
The atmosphere got thinner over time.
大气层越来越薄
Liquid water stopped being stable on the surface.
液态水也无法停留在火星表面了
And Mars kinda went into a stasis, a cold, dry stasis.
火星有点进入停滞 寒冷干涸的停滞
But could it happen on Earth?
但是地球会发生这样的事情吗
Certainly, at some point,
当然 在某一时刻
the Earth's magnetic field will shut down.
地球的磁场将会消失
But that's a long way off.
但是那还早着呢
A more immediate issue
更紧要的问题是
is when will the Earth's magnetic field reverse.
地磁场何时倒转
As we saw earlier,
正如我们所见
our planet reverses its field every few hundred thousand years,
地球的磁场每隔几十万年就会倒转一次
and we're overdue.
而这一次迟迟未到
When the Earth's magnetic field reverses,
在地磁场倒转的过程中
the process may leave Earth without a protective Magnetosphere
地球会失去磁层的保护
for a period of days or even longer.
这种情况会持续几天 甚至更长
This could lead to the very real possibility of the Mars scenario.
火星的悲剧很有可能因此重演
We're gonna see magnetic storms like
我们将会看到
we've never really experienced since modern civilization.
现代文明时代从未经历过的磁暴
But we don't need a planetary reversal to wreak havoc.
但是 未必需要等到行星磁场转换的那天
Experts say our entire society
专家分♥析♥ 一场磁暴就能
could be destroyed by a magnetic storm.
使整个社会陷入浩劫
Planetary disaster might be avoided,
想要避免星球被毁灭的命运
but steps must be taken soon,
必须尽快采取措施
and the clock is ticking toward magnetic apocalypse.
磁暴灾难迫在眉睫
Magnetic storms are some of the most powerful forces in our solar system,
磁暴是我们太阳系中最强大的力量之一
and they've been nearly completely overlooked by science.
而它们几乎一直被科学界所忽视
These storms have damaged our planet before.
磁暴曾经重创过我们的星球
In 1989, a solar flare hit north America,
1989年 一股太阳耀斑袭击了北美
wiping out power to Quebec and the surrounding area.
使魁北克及周围地区的电力系统陷入瘫痪
Six million people
在加拿大寒冷的冬天
were without power in the middle of a cold Canadian winter.
六百万人陷入了无电可用的境地
Electricity was restored within a day,
一天内 供电恢复
preventing a greater catastrophe.
阻止了一场更大的灾难
But the Quebec storm was a small one.
然而 袭击魁北克的磁暴只是米粒之珠
A far greater storm was actually recorded in 1859.
据记载 1859年发生了一次规模空前的磁暴
Northern lights were seen as far south as Cuba.
往南一直到古巴 都能看见北极光
Telegraph lines stretching across America
贯穿美国的电报线路
hummed and sparked as a massive power surge shorted them out.
被强大的磁浪摧毁 沿线嗡鸣火花不断
This may have been
这应该是
one of the largest geomagnetic storms that has ever occurred.
发生过的规模最大的磁暴之一了
Literally 10 times larger than what caused the problems
几乎是1989年袭击北美电网
in the north American grid in 1989.
磁暴规模的十倍
New data from SDO and other observatories show
来自SDO以及其它天文台的新的观测数据显示
that these massive solar storms
这些大规模太阳磁暴
are far more common than we once thought.
要比我们所料想的更加常见
What would happen if the same giant storm from 1859
如果1859年的大磁暴今天再次袭击地球
hit our planet today?
会发生什么呢
The disaster would begin with a sunspot erupting on the solar surface,
灾难将始于太阳表面的一次黑子爆发
firing billions of tons of material directly at Earth.
几十亿吨♥的太阳物质朝地球喷涌而来
In eight minutes,
不到8分钟
gamma rays and x-rays wipe out most satellites.
伽马射线和X射线将摧毁大多数卫星
Our wired society is now blinded.
网络社会一片黑暗
No GPS. No plane navigation.
GPS失灵 飞机导航失效
No satellite or cable television.
卫星有线电视关闭
We have hundreds and hundreds of hundreds of satellites in orbit.
数以百计的卫星在轨道上行驶
And on average, each of those satellites costs a half a billion dollars.
平均每颗卫星价值五亿美元
Well, there's hundreds of billions of dollars right there that's gone.
数千亿美元就这么没了
Within 8 to 16 hours, the great mass of ejected solar material
8到16个小时之后 大量日冕抛射物质
hits Earth's magnetosphere,
将冲击地球磁层
overwhelms it and blasts across the face of the planet.
瞬间突破它的保护 横扫地球表面
Infrastructure will start seeing large induced currents
在设备的大型输电线中
starting to flow through large power lines.
开始生成巨大的感应电流