TED@NAS
Mike Brown: The search for our solar system's ninth planet
迈克尔·E·布朗: 探索太阳系的第九大行星
Filmed:
Readability: 4.5
1,920,764 views
太阳系中遥远的，具有奇特轨道的小型星体能否将我们引向一个重大发现？ 行星天文学家迈克尔·E·布朗（Michael E. Brown）提出了一个新的巨型行星的存在——它潜伏在我们太阳系的远处——并向我们展示了其存在的痕迹，而它也可能正在远远地注视着我们。
Mike Brown - Planetary astronomer
Mike Brown scans the skies searching for and intensely studying distant bodies in our solar system in the hope of gaining insight into how our planet and the planets around it came to be. Full bio
Mike Brown scans the skies searching for and intensely studying distant bodies in our solar system in the hope of gaining insight into how our planet and the planets around it came to be. Full bio
Double-click the English transcript below to play the video.
我要给你们讲述一个
从 200 年前开始的故事。
从 200 年前开始的故事。
00:13
I'm going to tell you a story
from 200 years ago.
from 200 years ago.
0
1000
2792
1820 年，法国天文学家
阿列西·布瓦尔（Alexis Bouvard）
阿列西·布瓦尔（Alexis Bouvard）
00:16
In 1820, French astronomer Alexis Bouvard
1
4792
3267
差点成为了人类历史上
第二个发现行星的人。
第二个发现行星的人。
00:20
almost became the second person
in human history to discover a planet.
in human history to discover a planet.
2
8083
5226
他当时在用原始的星表
追踪夜间天王星
追踪夜间天王星
00:25
He'd been tracking the position
of Uranus across the night sky
of Uranus across the night sky
3
13333
3310
划过天空的位置，
00:28
using old star catalogs,
4
16667
1726
然而天王星并没有像他预测的那样
00:30
and it didn't quite go around the Sun
5
18417
2309
围绕着太阳转。
00:32
the way that his predictions
said it should.
said it should.
6
20750
2434
有时，它转得有点太快了，
00:35
Sometimes it was a little too fast,
7
23208
2101
有时，又转得有点太慢。
00:37
sometimes a little too slow.
8
25333
1685
布瓦尔知道他的预测是完美的，
00:39
Bouvard knew that
his predictions were perfect.
his predictions were perfect.
9
27042
3726
因此这一定是陈旧星表的
不准确性所导致的。
不准确性所导致的。
00:42
So it had to be that those
old star catalogs were bad.
old star catalogs were bad.
10
30792
3267
那天，他跟天文学家们说，
00:46
He told astronomers of the day,
11
34083
2060
“做更好的测量。”
00:48
"Do better measurements."
12
36167
2434
于是他们照做了。
00:50
So they did.
13
38625
1268
天文学家们花费了将近 20 年，
00:51
Astronomers spent the next two decades
14
39917
2142
一丝不苟的追踪
天王星划过天空的轨迹，
天王星划过天空的轨迹，
00:54
meticulously tracking the position
of Uranus across the sky,
of Uranus across the sky,
15
42083
4060
但是结果仍然
和布瓦尔的预测不一样。
和布瓦尔的预测不一样。
00:58
but it still didn't fit
Bouvard's predictions.
Bouvard's predictions.
16
46167
3684
直到 1840 年，事情变得很明显：
01:01
By 1840, it had become obvious.
17
49875
2143
问题不是出在那些陈旧的星表上，
01:04
The problem was not
with those old star catalogs,
with those old star catalogs,
18
52042
3059
而是在于那些预测。
01:07
the problem was with the predictions.
19
55125
2851
同时，天文学家们
知道这是为什么。
知道这是为什么。
01:10
And astronomers knew why.
20
58000
1518
他们意识到，
一定是有一个遥远的巨大行星，
一定是有一个遥远的巨大行星，
01:11
They realized that there must be
a distant, giant planet
a distant, giant planet
21
59542
4184
刚好在天王星轨道的后面，
01:15
just beyond the orbit of Uranus
22
63750
1684
影响着天王星的运行速度。
01:17
that was tugging along at that orbit,
23
65458
1810
有时推着它，导致它移动得太快，
01:19
sometimes pulling it along a bit too fast,
24
67292
2559
有时又会拽住它，
减慢它的运行速度。
减慢它的运行速度。
01:21
sometimes holding it back.
25
69875
1667
回到 1840 年，科学家一定很崩溃，
01:24
Must have been frustrating back in 1840
26
72750
2018
因为你能看到这些
相距遥远的巨行星重力效应，
相距遥远的巨行星重力效应，
01:26
to see these gravitational effects
of this distant, giant planet
of this distant, giant planet
27
74792
3392
却还不知道如何找到它。
01:30
but not yet know how to actually find it.
28
78208
3768
相信我，这真的很让人崩溃。
01:34
Trust me, it's really frustrating.
29
82000
2059
01:36
(Laughter)
30
84083
1476
（笑声）
但是到了 1846 年，
另外一个法国天文学家
另外一个法国天文学家
01:37
But in 1846, another French astronomer,
31
85583
2226
奥本·勒维耶（Urbain Le Verrier），
01:39
Urbain Le Verrier,
32
87833
1310
通过数学计算，
01:41
worked through the math
33
89167
1267
找到了如何预测行星位置的方法。
01:42
and figured out how to predict
the location of the planet.
the location of the planet.
34
90458
2726
他把他的预测结果发给了柏林天文台，
01:45
He sent his prediction
to the Berlin observatory,
to the Berlin observatory,
35
93208
2976
他们打开了望远镜，
01:48
they opened up their telescope
36
96208
1435
然后就在第一天晚上，
观测到了一个很微弱的光点，
观测到了一个很微弱的光点，
01:49
and in the very first night
they found this faint point of light
they found this faint point of light
37
97667
3059
缓慢的从天空划过，
01:52
slowly moving across the sky
38
100750
2101
然后发现了天王星。
01:54
and discovered Neptune.
39
102875
1268
它的位置和勒维耶的预测结果
在天空中就只差这么一点。
在天空中就只差这么一点。
01:56
It was this close on the sky
to Le Verrier's predicted location.
to Le Verrier's predicted location.
40
104167
4125
02:01
The story of prediction
and discrepancy and new theory
and discrepancy and new theory
41
109875
4518
这段关于预测、区别、新理论
以及成功发现的故事堪称经典，
02:06
and triumphant discoveries is so classic
42
114417
3059
勒维耶也因此成名，
02:09
and Le Verrier became so famous from it,
43
117500
2893
那些试图进入该领域的人
也立马行动了起来。
也立马行动了起来。
02:12
that people tried to get in
on the act right away.
on the act right away.
44
120417
2726
在过去的 163 年里，
02:15
In the last 163 years,
45
123167
2517
数十位天文学家
利用所谓的轨道偏差，
利用所谓的轨道偏差，
02:17
dozens of astronomers have used
some sort of alleged orbital discrepancy
some sort of alleged orbital discrepancy
46
125708
5601
来预测太阳系中是否存在新行星。
02:23
to predict the existence
of some new planet in the solar system.
of some new planet in the solar system.
47
131333
3917
但他们的预测
却一直出现各种问题。
却一直出现各种问题。
02:28
They have always been wrong.
48
136292
2708
最有名的一个错误预测
02:32
The most famous
of these erroneous predictions
of these erroneous predictions
49
140125
2184
来自于帕西瓦尔·罗威尔
（Percival Lowell），
（Percival Lowell），
02:34
came from Percival Lowell,
50
142333
1435
02:35
who was convinced that there must be
a planet just beyond Uranus and Neptune,
a planet just beyond Uranus and Neptune,
51
143792
4726
他坚信，在天王星和海王星后，
一定还有一个行星，
一定还有一个行星，
在干扰那些轨道。
02:40
messing with those orbits.
52
148542
1976
因此在 1930 年冥王星被发现于
02:42
And so when Pluto was discovered in 1930
53
150542
2559
02:45
at the Lowell Observatory,
54
153125
1643
洛厄尔天文台时，
02:46
everybody assumed that it must be
the planet that Lowell had predicted.
the planet that Lowell had predicted.
55
154792
4434
所有人都以为，那颗行星
一定就是罗威尔曾预测的那颗。
一定就是罗威尔曾预测的那颗。
但他们错了。
02:51
They were wrong.
56
159250
2393
02:53
It turns out, Uranus and Neptune
are exactly where they're supposed to be.
are exactly where they're supposed to be.
57
161667
4101
结果表明，天王星和海王星
就在它们应该在的地方。
就在它们应该在的地方。
这件事花费了 100 年的时间，
02:57
It took 100 years,
58
165792
1559
但是最终，人们发现布瓦尔是对的。
02:59
but Bouvard was eventually right.
59
167375
1768
天文学家们需要做更好的测量。
03:01
Astronomers needed to do
better measurements.
better measurements.
60
169167
3601
他们这么做了之后，
03:04
And when they did,
61
172792
1767
那些更好的测量表明，
03:06
those better measurements
had turned out that
had turned out that
62
174583
3185
在天王星和海王星的轨道后面
并没有行星的出现，
并没有行星的出现，
03:09
there is no planet just beyond
the orbit of Uranus and Neptune
the orbit of Uranus and Neptune
63
177792
5017
并且冥王星的体积
比预测的要小几千倍，
比预测的要小几千倍，
03:14
and Pluto is thousands of times too small
64
182833
2685
以至于对那些轨道
不会产生任何影响。
不会产生任何影响。
03:17
to have any effect on those orbits at all.
65
185542
2642
因此，尽管冥王星后来被证实
03:20
So even though Pluto
turned out not to be the planet
turned out not to be the planet
66
188208
3643
并非本意想要预测的那颗行星，
03:23
it was originally thought to be,
67
191875
1601
但这是目前对在已知行星外轨道上
03:25
it was the first discovery
of what is now known to be
of what is now known to be
68
193500
3434
存在的数千个微小的
结冰天体（柯伊伯带）的首次发现。
结冰天体（柯伊伯带）的首次发现。
03:28
thousands of tiny, icy objects
in orbit beyond the planets.
in orbit beyond the planets.
69
196958
4726
这里你可以看到木星、
03:33
Here you can see the orbits of Jupiter,
70
201708
2893
土星、天王星和海王星的轨道，
03:36
Saturn, Uranus and Neptune,
71
204625
2518
以及在那个小圆圈里，
最中间的地方就是地球，
最中间的地方就是地球，
03:39
and in that little circle
in the very center is the Earth
in the very center is the Earth
72
207167
3017
和太阳，以及所有
你知道并喜爱的一切。
你知道并喜爱的一切。
03:42
and the Sun and almost everything
that you know and love.
that you know and love.
73
210208
2976
那些边缘发黄的圈，
03:45
And those yellow circles at the edge
74
213208
1810
是在行星外围的结冰天体。
03:47
are these icy bodies
out beyond the planets.
out beyond the planets.
75
215042
2767
这些结冰天体
03:49
These icy bodies are pushed and pulled
76
217833
2268
03:52
by the gravitational fields of the planets
77
220125
2143
会因为行星的重力场，
03:54
in entirely predictable ways.
78
222292
2517
按照完全可预测的方式被推拉。
所有的行星基本上都在
以它们该有的方式
以它们该有的方式
03:56
Everything goes around the Sun
exactly the way it is supposed to.
exactly the way it is supposed to.
79
224833
4709
围绕着太阳转。
04:02
Almost.
80
230958
1268
在 2003 年，
04:04
So in 2003,
81
232250
2059
我发现了
04:06
I discovered what was at the time
82
234333
1893
当时在太阳系中探测到
的最遥远的已知天体。
的最遥远的已知天体。
04:08
the most distant known object
in the entire solar system.
in the entire solar system.
83
236250
3684
很难忽视远方那颗孤独的天体，
04:11
It's hard not to look
at that lonely body out there
at that lonely body out there
84
239958
2476
然后说，是的， 罗威尔错了，
04:14
and say, oh yeah, sure,
so Lowell was wrong,
so Lowell was wrong,
85
242458
2060
海王星之外并没有其他行星，
04:16
there was no planet just beyond Neptune,
86
244542
1934
但这一颗——这一颗可能是新的行星。
04:18
but this, this could be a new planet.
87
246500
2559
我们真正要问的是，
04:21
The real question we had was,
88
249083
1476
它以什么样的轨道围绕着太阳转？
04:22
what kind of orbit
does it have around the Sun?
does it have around the Sun?
89
250583
2310
它是否就像其他行星一样
04:24
Does it go in a circle around the Sun
90
252917
1934
绕着太阳以圆形的轨道旋转？
04:26
like a planet should?
91
254875
1559
还是就像冰带中
其他典型的结冰天体一样，
其他典型的结冰天体一样，
04:28
Or is it just a typical member
of this icy belt of bodies
of this icy belt of bodies
92
256458
3893
只是先前不小心被抛出去了，
现在在回归原轨道的路上？
现在在回归原轨道的路上？
04:32
that got a little bit tossed outward
and it's now on its way back in?
and it's now on its way back in?
93
260375
4059
这正是在 200 年前，
04:36
This is precisely the question
94
264458
2518
天文学家在研究天王星时
努力想要解答的问题。
努力想要解答的问题。
04:39
the astronomers were trying
to answer about Uranus 200 years ago.
to answer about Uranus 200 years ago.
95
267000
4601
他们是利用在发现天王星的 91 年前
04:43
They did it by using
overlooked observations of Uranus
overlooked observations of Uranus
96
271625
3768
所被忽略的观测资料，
04:47
from 91 years before its discovery
97
275417
2351
从而找到它的整个轨道的。
04:49
to figure out its entire orbit.
98
277792
1726
我们无法追溯回那么早的资料，
04:51
We couldn't go quite that far back,
99
279542
2017
但是我们在 13 年前的资料里
找到了对目标天体的观测记录。
找到了对目标天体的观测记录。
04:53
but we did find observations
of our object from 13 years earlier
of our object from 13 years earlier
100
281583
4601
这些资料让我们弄清了
它是如何绕太阳转的。
它是如何绕太阳转的。
04:58
that allowed us to figure out
how it went around the Sun.
how it went around the Sun.
101
286208
2685
那么问题是，
05:00
So the question is,
102
288917
1267
它是像行星一样
在圆形的轨道上绕着太阳转呢，
在圆形的轨道上绕着太阳转呢，
05:02
is it in a circular orbit
around the Sun, like a planet,
around the Sun, like a planet,
103
290208
2726
还是像那些结冰天体一样
05:04
or is it on its way back in,
104
292958
1393
在回程途中？
05:06
like one of these typical icy bodies?
105
294375
1893
答案是，
05:08
And the answer is
106
296292
1684
皆非。
05:10
no.
107
298000
1268
它拥有非常巨大的椭圆轨道，
05:11
It has a massively elongated orbit
108
299292
2767
使它绕太阳一周需要一万年的时间。
05:14
that takes 10,000 years
to go around the Sun.
to go around the Sun.
109
302083
3935
我们将这个天体
命名为塞德娜（Sedna），
命名为塞德娜（Sedna），
05:18
We named this object Sedna
110
306042
2017
是因纽特人海洋女神的名字，
05:20
after the Inuit goddess of the sea,
111
308083
1851
以致敬它一生都在冰冻的环境中。
05:21
in honor of the cold, icy places
where it spends all of its time.
where it spends all of its time.
112
309958
4060
我们现在知道塞德娜的体积
05:26
We now know that Sedna,
113
314042
1601
约是冥王星的三分之一，
05:27
it's about a third the size of Pluto
114
315667
1767
且是海王星外的那些结冰天体中，
05:29
and it's a relatively typical member
115
317458
2060
相对比较典型的一个天体。
05:31
of those icy bodies out beyond Neptune.
116
319542
2809
相对比较典型，
但不包括它的奇特的轨道。
但不包括它的奇特的轨道。
05:34
Relatively typical,
except for this bizarre orbit.
except for this bizarre orbit.
117
322375
3851
你看着这个轨道可能会说，
05:38
You might look at this orbit and say,
118
326250
1768
“绕着太阳能走一万年确实很奇特”，
05:40
"Yeah, that's bizarre,
10,000 years to go around the Sun,"
10,000 years to go around the Sun,"
119
328042
2726
但这还不是它奇特的地方，
05:42
but that's not really the bizarre part.
120
330792
1934
奇特的是，在那一万年中，
05:44
The bizarre part is
that in those 10,000 years,
that in those 10,000 years,
121
332750
2191
塞德娜完全不接近
太阳系中的任何其他东西。
太阳系中的任何其他东西。
05:46
Sedna never comes close
to anything else in the solar system.
to anything else in the solar system.
122
334965
3969
即使是在它离太阳最近的位置，
05:50
Even at its closest approach to the Sun,
123
338958
2310
塞德娜和海王星的距离
05:53
Sedna is further from Neptune
124
341292
2309
也比海王星和地球之间的距离更远。
05:55
than Neptune is from the Earth.
125
343625
2208
假如塞德娜有这样的轨道：
05:59
If Sedna had had an orbit like this,
126
347042
2142
绕行太阳一圈就会和
海王星的轨道接触一次，
海王星的轨道接触一次，
06:01
that kisses the orbit of Neptune
once around the Sun,
once around the Sun,
127
349208
2601
那这就很容易解释了。
06:03
that would have actually been
really easy to explain.
really easy to explain.
128
351833
3018
那它就是在结冰天体
06:06
That would have just been an object
129
354875
1768
的区域中以圆形轨道
绕行太阳的天体，
绕行太阳的天体，
06:08
that had been in
a circular orbit around the Sun
a circular orbit around the Sun
130
356667
2267
有一瞬间太靠近海王星，
06:10
in that region of icy bodies,
131
358958
1435
因此被弹了出去，
06:12
had gotten a little bit
too close to Neptune one time,
too close to Neptune one time,
132
360417
2524
现在正在返回的途中。
06:14
and then got slingshot out
and is now on its way back in.
and is now on its way back in.
133
362965
2834
但是塞德娜从未接近过
太阳系中任何已知的东西，
太阳系中任何已知的东西，
06:19
But Sedna never comes close
to anything known in the solar system
to anything known in the solar system
134
367333
4726
不可能造成那样的弹射。
06:24
that could have given it that slingshot.
135
372083
2393
既然不是海王星造成的，
06:26
Neptune can't be responsible,
136
374500
2018
那一定有别的原因。
06:28
but something had to be responsible.
137
376542
3101
这是自 1845 年以来
06:31
This was the first time since 1845
138
379667
2934
我们第一次看到了在外太阳系的
某个东西产生了重力效应，
某个东西产生了重力效应，
06:34
that we saw the gravitational effects
of something in the outer solar system
of something in the outer solar system
139
382625
4934
06:39
and didn't know what it was.
140
387583
1500
但不知道它是什么。
我曾经以为自己知道答案。
06:42
I actually thought I knew
what the answer was.
what the answer was.
141
390208
2893
的确，它有可能是外太阳系一颗
06:45
Sure, it could have been
some distant, giant planet
some distant, giant planet
142
393125
4018
很遥远的巨大行星，
06:49
in the outer solar system,
143
397167
1267
但在这个情况中，这个想法很荒谬，
06:50
but by this time,
that idea was so ridiculous
that idea was so ridiculous
144
398458
2351
完全不足为信，
06:52
and had been so thoroughly discredited
145
400833
1851
所以我没有很严肃的对待它。
06:54
that I didn't take it very seriously.
146
402708
1810
但在 45 亿年前，
06:56
But 4.5 billion years ago,
147
404542
1267
当太阳在其它上百个天体的
包裹下形成时，
包裹下形成时，
06:57
when the Sun formed in a cocoon
of hundreds of other stars,
of hundreds of other stars,
148
405833
4851
那些天体中的任何一个
07:02
any one of those stars
149
410708
1268
都有可能太靠近塞德娜，
07:04
could have gotten
just a little bit too close to Sedna
just a little bit too close to Sedna
150
412000
2643
从而影响它，
让它进入现今的这个轨道中。
让它进入现今的这个轨道中。
07:06
and perturbed it onto the orbit
that it has today.
that it has today.
151
414667
3976
当那群天体消散在星系中，
07:10
When that cluster of stars
dissipated into the galaxy,
dissipated into the galaxy,
152
418667
3892
塞德娜的轨道应该会变成
太阳最早期历史中
太阳最早期历史中
07:14
the orbit of Sedna would have been
left as a fossil record
left as a fossil record
153
422583
3768
07:18
of this earliest history of the Sun.
154
426375
2476
的化石记录。
这个想法让我很兴奋，
07:20
I was so excited by this idea,
155
428875
1809
这表示我们可以去研究
07:22
by the idea that we could look
156
430708
1476
太阳诞生的化石历史，
07:24
at the fossil history
of the birth of the Sun,
of the birth of the Sun,
157
432208
2226
于是我用接下来十年的时间，
07:26
that I spent the next decade
158
434458
1601
去寻找更多有着
类似塞德娜轨道的天体。
类似塞德娜轨道的天体。
07:28
looking for more objects
with orbits like Sedna.
with orbits like Sedna.
159
436083
2726
在那十年间，我一个也没找到。
07:30
In that ten-year period, I found zero.
160
438833
3435
（笑声）
07:34
(Laughter)
161
442292
1017
但我的同事，查理·楚基罗
和史考特·雪柏，有了些发现。
和史考特·雪柏，有了些发现。
07:35
But my colleagues, Chad Trujillo
and Scott Sheppard, did a better job,
and Scott Sheppard, did a better job,
162
443333
3518
他们现在已经找到了
好几个轨道类似塞德娜的天体。
好几个轨道类似塞德娜的天体。
07:38
and they have now found several objects
with orbits like Sedna,
with orbits like Sedna,
163
446875
3018
这非常令人兴奋。
07:41
which is super exciting.
164
449917
1767
但更让人激动的是，
07:43
But what's even more interesting
165
451708
1524
他们发现，所有这些天体，
07:45
is that they found that all these objects
166
453256
2762
不仅是在遥远，椭圆形
的轨道上运行，
的轨道上运行，
07:48
are not only on these distant,
elongated orbits,
elongated orbits,
167
456042
3892
而且具有相同的复杂轨道参数特征。
07:51
they also share a common value
of this obscure orbital parameter
of this obscure orbital parameter
168
459958
5351
在天体力学中，
我们把这个参数称为近日点幅角。
我们把这个参数称为近日点幅角。
07:57
that in celestial mechanics we call
argument of perihelion.
argument of perihelion.
169
465333
3959
当他们发现那些特征参数
集聚在近日点幅角时，
集聚在近日点幅角时，
08:02
When they realized it was clustered
in argument of perihelion,
in argument of perihelion,
170
470250
2934
立即手舞足蹈起来，
08:05
they immediately jumped up and down,
171
473208
1768
因为他们认为一定有个
遥远的巨大行星存在。
遥远的巨大行星存在。
08:07
saying it must be caused
by a distant, giant planet out there,
by a distant, giant planet out there,
172
475000
2976
这真的让人很兴奋，
只是完全不合理罢了。
只是完全不合理罢了。
08:10
which is really exciting,
except it makes no sense at all.
except it makes no sense at all.
173
478000
3059
让我试着用一个比喻
来解释为什么。
来解释为什么。
08:13
Let me try to explain it
to you why with an analogy.
to you why with an analogy.
174
481083
2518
试想，一个人走在广场上，
08:15
Imagine a person walking down a plaza
175
483625
3309
看向他右边 45 度的方向。
08:18
and looking 45 degrees to his right side.
176
486958
3334
这可能有很多理由，
08:23
There's a lot of reasons
that might happen,
that might happen,
177
491125
2059
很容易解释，不是什么大事儿。
08:25
it's super easy to explain, no big deal.
178
493208
1935
现在试想，有很多不同的人
08:27
Imagine now many different people,
179
495167
1809
都在广场上朝不同的方向走，
08:29
all walking in different
directions across the plaza,
directions across the plaza,
180
497000
3893
但都看向他们行进方向的 45 度角。
08:32
but all looking 45 degrees
to the direction that they're moving.
to the direction that they're moving.
181
500917
3267
大家行进的方向不同，
08:36
Everybody's moving
in different directions,
in different directions,
182
504208
2018
大家看去的方向也不同，
08:38
everybody's looking
in different directions,
in different directions,
183
506250
2143
但他们看去的
都是行进方向的 45 度处，
都是行进方向的 45 度处，
08:40
but they're all looking 45 degrees
to the direction of motion.
to the direction of motion.
184
508417
3309
这个现象背后的原因会是什么？
08:43
What could cause something like that?
185
511750
1833
我不知道。
08:46
I have no idea.
186
514917
1267
非常难想象出任何理由
会造成这个现象。
会造成这个现象。
08:48
It's very difficult to think of any reason
that that would happen.
that that would happen.
187
516208
3726
（笑声）
08:51
(Laughter)
188
519958
1351
基本上，这就是
一堆相近的近日点幅角
一堆相近的近日点幅角
08:53
And this is essentially
what that clustering
what that clustering
189
521333
2851
08:56
in argument of perihelion was telling us.
190
524208
3393
告诉我们的事。
科学家们很受挫，
他们认为一定是侥幸
他们认为一定是侥幸
08:59
Scientists were generally baffled
and they assumed it must just be a fluke
and they assumed it must just be a fluke
191
527625
3559
和不佳的观测造成的。
09:03
and some bad observations.
192
531208
1351
他们告诉天文学家，
09:04
They told the astronomers,
193
532583
1768
“把观测做得更好一点”。
09:06
"Do better measurements."
194
534375
2393
我其实非常仔细地
研究过这些测量值，
研究过这些测量值，
09:08
I actually took a very careful look
at those measurements, though,
at those measurements, though,
195
536792
3101
但它们是对的。
09:11
and they were right.
196
539917
1267
这些天体真的都用
09:13
These objects really did all share
197
541208
1893
同样的近日点幅角值，
09:15
a common value of argument of perihelion,
198
543125
2476
但是这不应该。
09:17
and they shouldn't.
199
545625
1393
背后一定有原因。
09:19
Something had to be causing that.
200
547042
2208
谜团的最后一片出现在 2016 年，
09:23
The final piece of the puzzle
came into place in 2016,
came into place in 2016,
201
551125
4309
当我和隔壁办公室的同事
09:27
when my colleague, Konstantin Batygin,
202
555458
2518
康斯坦丁·巴蒂金意识到
09:30
who works three doors down from me, and I
203
558000
2643
大家之所以那么受挫
09:32
realized that the reason
that everybody was baffled
that everybody was baffled
204
560667
2601
是因为近日点幅角只是
故事的一部分。
故事的一部分。
09:35
was because argument of perihelion
was only part of the story.
was only part of the story.
205
563292
4726
如果你用对的方式
来观察这些天体，
来观察这些天体，
09:40
If you look at these
objects the right way,
objects the right way,
206
568042
2059
它们实际上在宇宙中
呈队列排布，并面朝同样的方向，
呈队列排布，并面朝同样的方向，
09:42
they are all actually lined up
in space in the same direction,
in space in the same direction,
207
570125
4059
以同样的角度倾斜。
09:46
and they're all tilted in space
in the same direction.
in the same direction.
208
574208
3726
就好像在广场上的那些人们
都朝向相同的方向行进，
都朝向相同的方向行进，
09:49
It's as if all those people on the plaza
are all walking in the same direction
are all walking in the same direction
209
577958
4351
并且他们都看向右边 45 度。
09:54
and they're all looking
45 degrees to the right side.
45 degrees to the right side.
210
582333
3435
这很容易解释。
09:57
That's easy to explain.
211
585792
1267
因为他们都在看向某个东西。
09:59
They're all looking at something.
212
587083
2476
在外太阳系的这些天体都
受到某个东西的影响。
受到某个东西的影响。
10:01
These objects in the outer solar system
are all reacting to something.
are all reacting to something.
213
589583
4125
但那是什么呢？
10:07
But what?
214
595000
1726
我和康斯坦丁花了一年的时间，
10:08
Konstantin and I spent a year
215
596750
2976
尝试去找出一个不同的解释，
不同于在外太阳系中
不同于在外太阳系中
10:11
trying to come up with any explanation
other than a distant, giant planet
other than a distant, giant planet
216
599750
4809
有遥远且巨大行星的解释。
10:16
in the outer solar system.
217
604583
1268
我们并不想要成为第 33 和 34 位
提出这个行星存在
提出这个行星存在
10:17
We did not want to be the 33rd and 34th
people in history to propose this planet
people in history to propose this planet
218
605875
5434
又被告知弄错了的人。
10:23
to yet again be told we were wrong.
219
611333
2334
但一年后，
10:26
But after a year,
220
614792
1767
真的没有别的选择。
10:28
there was really no choice.
221
616583
1310
除了之前的那个解释，
10:29
We could come up with no other explanation
222
617917
2142
我们想不出其他的解释了：
10:32
other than that there is a distant,
223
620083
2500
可能有个遥远的巨大行星
沿着椭圆的轨道运行，
沿着椭圆的轨道运行，
10:34
massive planet on an elongated orbit,
224
622625
3268
倾斜向这个太阳系的其他部分，
10:37
inclined to the rest of the solar system,
225
625917
2059
从而被迫形成这些
10:40
that is forcing these patterns
for these objects
for these objects
226
628000
2726
外太阳系天体的模式。
10:42
in the outer solar system.
227
630750
2018
猜一下这样的行星还会做什么？
10:44
Guess what else a planet like this does.
228
632792
2142
还记得塞德娜那奇特的轨道吗？
10:46
Remember that strange orbit of Sedna,
229
634958
1851
那个轨道似乎被朝着
一个方向拉离太阳。
一个方向拉离太阳。
10:48
how it was kind of pulled away
from the Sun in one direction?
from the Sun in one direction?
230
636833
2935
这样的一个行星会
不分昼夜地产生那样的轨道。
不分昼夜地产生那样的轨道。
10:51
A planet like this would make
orbits like that all day long.
orbits like that all day long.
231
639792
3726
我们知道事情有些眉目了。
10:55
We knew we were onto something.
232
643542
2309
这就把我们带到了今天。
10:57
So this brings us to today.
233
645875
2976
我们的处境基本上
就是 1845 年的巴黎。
就是 1845 年的巴黎。
11:00
We are basically 1845, Paris.
234
648875
4184
（笑声）
11:05
(Laughter)
235
653083
1185
我们看到遥远的巨大行星
造成的重力效应，
造成的重力效应，
11:06
We see the gravitational effects
of a distant, giant planet,
of a distant, giant planet,
236
654292
5309
于是我们试着计算出
11:11
and we are trying to work out
the calculations
the calculations
237
659625
2226
11:13
to tell us where to look,
to point our telescopes,
to point our telescopes,
238
661875
3018
望远镜应该转向的方向，
希望能找到这个行星。
11:16
to find this planet.
239
664917
1267
我们做过大量的电脑模拟，
11:18
We've done massive suites
of computer simulations,
of computer simulations,
240
666208
2375
投入无数个月做分析计算，
11:21
massive months of analytic calculations
241
669292
1934
目前我能告诉各位的是：
11:23
and here's what I can tell you so far.
242
671250
2559
11:25
First, this planet,
which we call Planet Nine,
which we call Planet Nine,
243
673833
3185
首先，我们把这颗行星
称为第九行星，
称为第九行星，
因为它就是第九个。
11:29
because that's what it is,
244
677042
2583
第九行星的质量是地球的 6 倍。
11:32
Planet Nine is six times
the mass of the Earth.
the mass of the Earth.
245
680750
3268
这并非“它比冥王星小一点，
11:36
This is no slightly-smaller-than-Pluto,
246
684042
2226
争论一下它是不是行星”的情形。
11:38
let's-all-argue-about-
whether-it's-a-planet-or-not thing.
whether-it's-a-planet-or-not thing.
247
686292
2726
这是我们整个太阳系中
第五大的行星。
第五大的行星。
11:41
This is the fifth largest planet
in our entire solar system.
in our entire solar system.
248
689042
3309
我先让各位对比一下
这些行星的大小。
这些行星的大小。
11:44
For context, let me show you
the sizes of the planets.
the sizes of the planets.
249
692375
3643
在后方，你可以看到
巨大的木星和土星。
巨大的木星和土星。
11:48
In the back there,
you can the massive Jupiter and Saturn.
you can the massive Jupiter and Saturn.
250
696042
4142
在它们旁边是稍小一点
的天王星和海王星。
的天王星和海王星。
11:52
Next to them, a little bit smaller,
Uranus and Neptune.
Uranus and Neptune.
251
700208
2643
在上面角落的是类地行星：
水星、金星、地球、火星。
水星、金星、地球、火星。
11:54
Up in the corner, the terrestrial planets,
Mercury, Venus, Earth and Mars.
Mercury, Venus, Earth and Mars.
252
702875
3477
你甚至可以看到
11:58
You can even see that belt
253
706376
1350
海王星外面的结冰带，
而且冥王星也是其中一员。
而且冥王星也是其中一员。
11:59
of icy bodies beyond Neptune,
of which Pluto is a member,
of which Pluto is a member,
254
707750
3143
看看你们能不能分清谁是谁。
12:02
good luck figuring out which one it is.
255
710917
1858
这里是第九行星。
12:04
And here is Planet Nine.
256
712799
2416
第九行星很大。
12:08
Planet Nine is big.
257
716583
2435
第九行星大到
12:11
Planet Nine is so big,
258
719042
1267
你应该纳闷，为什么
我们还没有找到它。
我们还没有找到它。
12:12
you should probably wonder
why haven't we found it yet.
why haven't we found it yet.
259
720333
2601
第九行星的确很大，
12:14
Well, Planet Nine is big,
260
722958
1268
但它也非常、非常的远。
12:16
but it's also really, really far away.
261
724250
2101
它所在的位置可能
比海王星还要远十五倍。
比海王星还要远十五倍。
12:18
It's something like
15 times further away than Neptune.
15 times further away than Neptune.
262
726375
4684
这同时意味着它的亮度
比海王星还要微弱五万倍。
比海王星还要微弱五万倍。
12:23
And that makes it about 50,000 times
fainter than Neptune.
fainter than Neptune.
263
731083
3268
此外，天空真的是一个很大的空间。
12:26
And also, the sky is a really big place.
264
734375
2934
我们已经把它的定位范围
12:29
We've narrowed down where we think it is
265
737333
2143
缩小成天空中相对很小的一块区域。
12:31
to a relatively small area of the sky,
266
739500
2518
但我们仍然要花数年的时间
12:34
but it would still take us years
267
742042
1892
才能系统性地覆盖到整个区域，
12:35
to systematically cover
the area of the sky
the area of the sky
268
743958
2351
而且还得使用很大的望远镜
12:38
with the large telescopes that we need
269
746333
1851
才能看到那么遥远，那么微弱的行星。
12:40
to see something that's
this far away and this faint.
this far away and this faint.
270
748208
3310
幸运的是，我们可能不用这么做。
12:43
Luckily, we might not have to.
271
751542
3142
就像布瓦尔使用
12:46
Just like Bouvard used
unrecognized observations of Uranus
unrecognized observations of Uranus
272
754708
4893
在天王星被发现的 91 年前
未能识别出天王星的观测资料，
未能识别出天王星的观测资料，
12:51
from 91 years before its discovery,
273
759625
2768
我敢说一定有那些
未能识别出的影像
未能识别出的影像
12:54
I bet that there are unrecognized images
274
762417
3767
可以显示出第九行星的位置。
12:58
that show the location of Planet Nine.
275
766208
2875
13:02
It's going to be a massive
computational undertaking
computational undertaking
276
770000
3059
这势必要用到非常大量的计算
13:05
to go through all of the old data
277
773083
2310
才能分析完所有的旧资料，
13:07
and pick out that one faint moving planet.
278
775417
2916
并挑出那一个亮度微弱的移动行星。
我们正在做这件事了，
13:11
But we're underway.
279
779292
1351
并且我认为
我们离成功越来越近了。
我们离成功越来越近了。
13:12
And I think we're getting close.
280
780667
2309
所以，我要说的是，准备好。
13:15
So I would say, get ready.
281
783000
2518
我们并不是要追赶勒维耶的记录：
13:17
We are not going to match Le Verrier's
282
785542
3976
“做一个预测，
13:21
"make a prediction,
283
789542
1267
第一个晚上就在离预测位置
13:22
have the planet found in a single night
284
790833
1893
不远处找到了行星”。
13:24
that close to where
you predicted it" record.
you predicted it" record.
285
792750
2184
但我敢说，在接下来几年内，
13:26
But I do bet that within
the next couple of years
the next couple of years
286
794958
3935
某地的某个天文学家
13:30
some astronomer somewhere
287
798917
2392
会发现一个微弱的光点
13:33
will find a faint point of light,
288
801333
2226
缓慢的在天空中移动，
13:35
slowly moving across the sky
289
803583
2268
并得意洋洋地宣布
一颗新行星的发现，
一颗新行星的发现，
13:37
and triumphantly announce
the discovery of a new,
the discovery of a new,
290
805875
3309
而且可能还不是我们太阳系中
13:41
and quite possibly not the last,
291
809208
2435
13:43
real planet of our solar system.
292
811667
2476
·真实存在的最后一颗行星。
谢谢。
13:46
Thank you.
293
814167
1267
（掌声）
13:47
(Applause)
294
815458
3625
ABOUT THE SPEAKER
Mike Brown - Planetary astronomerMike Brown scans the skies searching for and intensely studying distant bodies in our solar system in the hope of gaining insight into how our planet and the planets around it came to be.
Why you should listen
Mike Brown has discovered dozens of dwarf planets (and demoted one object from planet to dwarf planet) and is currently hot on the trail of Planet Nine -- a hypothesized body that is possibly the fifth largest planet of our solar system.
Brown is the Richard and Barbara Rosenberg Professor of Planetary Astronomy at the California Institute of Technology and has been on the faculty there since 1996. He has won many awards and honors for his scholarship, including the Urey Prize for best young planetary scientist from the American Astronomical Society's Division of Planetary Sciences; a Presidential Early Career Award; a Sloan Fellowship; the 2012 Kavli Prize in Astrophysics; and, of course, the one that started his career, an honorable mention in his fifth-grade science fair. He was inducted into the National Academy of Science in 2014. He was also named one of Wired Online's Top Ten Sexiest Geeks in 2006, the mention of which never ceases to make his wife laugh.
Brown received his AB from Princeton in 1987 and his MA and PhD from University of California, Berkeley, in 1990 and 1994, respectively. He is the author of How I Killed Pluto and Why It Had It Coming, a memoir of the discoveries leading to the demotion of Pluto.
Mike Brown | Speaker | TED.com