追逐冥王星（2015）

他设法在太阳系的遥远深处
he searched for another planet
寻找其他行星
in the far reaches of the solar system.
虽然他跟其他天文学家辛勤搜寻
But as hard as he and other astronomers looked--
他们真的很努力
and they looked hard
不过还是没有发现新东西
nobody found anything.
后来戴维朱特和刘丽杏，接下这项挑战
Until astronomers David Jewitt and Jane Luu took on the challenge.
他们展开的探索工作
They started a search that would take a lot longer
耗费了他们想象不到的时间
than they could ever imagine.
为什么花那么长时间？
Why did it take so long?
因为科技发展赶不上问题的难度
It was a matter of technology catching up with the problem.
要看到遥远的恒星很容易
While it's easy to see distant stars
因为它们会发射光线
because they radiate light,
但要看到其他天体则困难许多
other celestial bodies are much harder to see.
这是因为光线必须从太阳照射到遥远星体
That's because light has to travel all the way from our Sun to the object,
在它的表面反射之后
reflect off its surface,
再往回传播到地球
and then make the long journey back to Earth.
这时光线已经几乎看不到了
By then,it's barely visible.
戴维和丽杏希望数字探测器的发展
David and Jane hoped that advances in digital detectors,
可以使他们看到更多东西
now standard in today's smartphones,
它也是目前智能型手♥机♥的标准配备
would help them see a whole lot more.
经过五年的搜寻
After searching for five years,
他们终于找到东西了
they finally found something.
这是发现第一个物体时的系列照片
Here is the set of discovery images for the first object.
我们可以看到从这张照片
So you can see this object drifting from
到这张，然后到这张
this picture to this one to this one.
它一直在动，慢慢往左边移♥动♥
It's drifting slowly to the left.
后来他们又发现其他缓慢移♥动♥的物体
When they found several more of these slow-moving objects,
于是他们终于能够宣布
David and Jane could finally declare
冥王星并不寂寞
Pluto is not alone.
它其实有很多邻居
In fact,it's got plenty of neighbors.
他们把这个太阳系的新区域，命名为古柏带
They named this new region of the solar system
向天文学家杰拉古柏致意
the Kuiper Belt,after Gerard Kuiper,
古柏早在1950年代就提出这个区域存在的假设
the astronomer who proposed its existence back in the 1950s.
古柏带的发现以非常深刻的方式
The discovery of the Kuiper Belt expanded our
扩展了我们对太阳系的了解
understanding of the solar system in a profound way,
不过这也威胁到冥王星的行星地位
but it also put Pluto's planetary status in jeopardy.
它到底是行星
Is it a planet
或只是古柏带众多物体之一？
or a Kuiper Belt object,one of many?
我爸爸知道这件事会引发争论
My Dad knew there were rumblings in the wind,
他觉得很难过
and it upset him.
那让我父亲非常苦恼
It certainly was not easy for my father.
但终极的打击才要发生
But the final blow was yet to come.
几年以后
A few years later,
一名年轻天文学家
a young astronomer
决定在外太阳系寻找更多星体
decided to look for more objects in the outer solar system.
麦克布朗决定做一件伟大的事
Mike Brown was determined to do something really big:
找到比冥王星更大的古柏带物体
find a Kuiper Belt object larger than Pluto.
我们甚至认为也许可以找到
We even thought we might be finding things
像火星甚至地球那么大的物体
the size of Mars,the size of the Earth.
不过一切都还是未知
We really had no idea.
我们在1997年，展开这个工作时
So when we started off doing this back in 1997,
非常兴奋地想知道
it was pretty exciting
那遥远的地方会有什么东西
to think what might be out there.
在加州的帕洛玛天文台
At the Palomar Observatory in California,
麦克可以近用全世界最大的数字相机
Mike had access to the largest digital camera on earth.
影像会上传到他的计算机
The images were uploaded to his computer,
他每天早上会加以分♥析♥
where he analyzed them every morning.
有了先进科技加持
With technology on his side,
新发现不断出现
the discoveries just kept on coming.
我们找到“夸欧尔”(创神星)
We found Quaoar,
它是古柏带的一个星体
which is an object out in the Kuiper Belt
大约有冥王星的一半大
that's about half the size of Pluto.
来年我们又发现相当于
The next year,we found something
冥王星四分之三大小的星体
about three-quarters the size of Pluto,
再隔一年我们发现这个非常亮的东西
and in the following year,we found this thing,
它移♥动♥得极为缓慢
and it was so bright and also moving so slowly,
因为极为遥远
moving so slowly
所以看起来移♥动♥得很慢
because it was so far away.
经过这么久的努力
After all this time,
麦克难以相信他可能终于找到
Mike couldn't believe he might finally have
他一直在寻找的东西
found what he had been looking for.
我看着它，心想这不可能啊
I looked at it and I thought,"This can't be right."
如果它那么亮，移♥动♥得又那么慢
If it's that bright and moving that slowly,
那它真的是我们找到的最远的东西
it's the furthest thing we've ever found
也是最大的东西
and it's the biggest thing we've ever found,
它一定非常大，想必比冥王星更大
and it must be bigger than Pluto,
这大疯狂了
and that's crazy.
在被发现的星体之中
It was the first object to be discovered
那是第一个，可能比冥王星大的东西
that could have been larger than Pluto.
于是学界一片喧嚣
That caused a ruckus because,
因为如果冥王星是行星
well,if Pluto's a planet,
这一定也是行星，对吧?
then this has got to be a planet,right?
那这些东西该怎么叫才对？
And so what are we going to call these things?
多数人在意的不是我们刚发现的这个物体
Most people really didn't care that much about this thing that we just discovered.
他们想知道的是
They wanted to know,
“这对冥王星而言代表什么?”
"Well,what does it mean for Pluto?"
意思就是说“喔 你发现比冥王星大的东西”
It's like,"Oh,yeah,you found something bigger than Pluto.
“但这对冥王星而言，代表什么？”
But what does it mean for Pluto?"
过去一个世纪以来
For the past century,
国际天文联会负责为星体命名
the IAU--the International Astronomical Union--
但如果不知道麦克发现的
has been in charge of naming celestial objects,
到底是一颗古柏带星体，还是第十颗行星
but it couldn't give Mike's discovery a name
联会就无法为它命名
without knowing if it was a Kuiper Belt object or the tenth planet.
我认为这开启了非常有趣的对话
I think it started an interesting conversation
因为我们其实无法精确定义行星这个概念
because we didn't really have a definition for planets,okay?
这个词源自希腊文“漂泊的星球”
You know,it came from the Greek "wandering star,"
我们确实有需要找到更好的分类方式
and we did need a better way of classifying things
藉以界定太阳系中的行星以及其他物体
as being planets or small bodies in the solar system.
国际天文联会在布拉格开会时
At the IAU meeting in Prague,a vote was taken
为“行星”一词的定义进行表决
on a new definition of the word "planet."
冥王星的命运最后取决于
Pluto's fate came down to the
这么简单的一句话
phrasing of just one line:
“行星能有效清扫其运行轨道的周边环境”
"a planet has cleared the neighborhood around its orbit."
冥王星存在于一个拥挤的环境中
Pluto resides in a crowded neighborhood
那里充满数以千计古柏带星体
filled with thousands of Kuiper Belt objects.
不若那些比较大的行星
Unlike larger planets,
小小的冥王星不具备足够重力
tiny Pluto doesn't have enough
因此无法将那些星体，扫出运行轨道
gravity to clear them out of its way.
而且冥王星的轨道呈扁椭圆
It also has an extreme elliptical orbit
跟太阳系其他行星位于不同平面
not on the same plane as the rest of the planets.
太阳系中有8个地位重要的物体
Eight major things which dominate the solar system
叫作行星
are planets.
它们都非常大
They're all big.
它们在圆形轨道上绕着太阳转
They go in circular orbits in one disk around the Sun.
其他一切都很小
And everything else is much smaller.
那些不叫行星
Those are not planets.
因此根据国际天文联会
So according to the IAU,
冥王星不是行星
Pluto is not a planet;
而是“矮行星”
it's a "dwarf planet."
学界逐渐形成一种共识认为
There has been a consensus developed
冥王星是矮行星
that Pluto is a dwarf planet,and you know,
这点我没意见
I have no problem with that.
这里的争议性在于
The controversy comes in when you try to say
是否矮行星就不能叫行星
a dwarf planet is not a planet.
如果把“行星”在这个新名词里面
Well,it seems a little ridiculous to have "planet" in the word,
然后又说它不是行星
the designation for an object,
那实在有点荒谬
and say somehow it's not a planet.
就某方面而言
In a sense,this question
怎么为某些物体贴标签，不是太重要
of how do you label certain objects
比较重要的是能够体认
is less important than understanding