ABOUT THE SPEAKER
Anjali Tripathi - Astrophysicist
Anjali Tripathi explores planets to uncover the processes that make and destroy them.

Why you should listen

Even though Anjali Tripathi worked on NASA's Mars rovers in high school, the California native never expected to become an astronomer. Unlike the earthquakes she researched early on, astronomy seemed unconnected from daily life. As she has since discovered, exploring distant planets has a lot to do with life itself -- including the fate of the air we breathe. Using some of the most powerful telescopes and supercomputers, Tripathi studies how seemingly permanent planets change over time. She has pioneered the characterization of planet-forming environments and developed computer simulations to trace the 3D structure of planet atmospheres that are shrinking due to evaporation.

A natural teacher, Tripathi makes complex science concepts relevant and easy to understand. She believes that everyone can understand science -- even rocket science. She has partnered with the Smithsonian, Teach for America and others to increase scientific literacy and spread enthusiasm for the subject. Her engaging and humorous talks feature real world connections and unusual props, including a fully functioning Mars Pathfinder rover or full-size solar car.

Tripathi earned degrees in physics and astronomy from M.I.T., the University of Cambridge and Harvard University. Recognized as a promising American leader with a commitment to public service, Tripathi is a 2016-17 White House Fellow.


More profile about the speaker
Anjali Tripathi | Speaker | TED.com
TEDxBeaconStreet

Anjali Tripathi: Why Earth may someday look like Mars

安佳丽 特里帕西: 为何地球终有一日将变成火星

Filmed:
1,203,838 views

每一分钟就会有四百磅氢气和几乎七磅氦气从地球大气层飞向外太空。天体物理学家——安佳丽 特里帕西研究了大气逃离的现象。在此次精彩演讲中,她将介绍为何这个现象会在几百万年后的某一天,将我们蓝色的地球变成红色。
- Astrophysicist
Anjali Tripathi explores planets to uncover the processes that make and destroy them. Full bio

Double-click the English transcript below to play the video.

00:12
So when you look out
at the stars明星 at night,
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當你擡頭看夜空中的繁星,
00:15
it's amazing驚人 what you can see.
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你所見到的,是多麼奇妙。
00:17
It's beautiful美麗.
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多麽美好。
00:18
But what's more amazing驚人
is what you can't see,
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但更奇妙的是那些你看不見的,
00:21
because what we know now
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因為根據人類已知,
00:23
is that around every一切 star
or almost幾乎 every一切 star,
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幾乎在每一顆恒星周圍
00:26
there's a planet行星,
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都有一颗行星,
00:27
or probably大概 a few少數.
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甚至若幹個。
00:30
So what this picture圖片 isn't showing展示 you
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這幅圖片沒能告訴你的是
00:32
are all the planets行星 that we know about
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在這個宇宙中存在著的
00:34
out there in space空間.
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所有的行星。
00:36
But when we think about planets行星,
we tend趨向 to think of faraway遠處 things
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當我們提起“行星”,我們總會覺得,它們是離我們很遙遠的東西
00:39
that are very different不同 from our own擁有.
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跟我們自己的星球很不一樣。
00:41
But here we are on a planet行星,
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但我們現在正正身處在一個行星,
00:43
and there are so many許多 things
that are amazing驚人 about Earth地球
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而且有太多美妙的事物在這個地球,
00:47
that we're searching搜索 far and wide
to find things that are like that.
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我們正在深入發掘和探索。
00:51
And when we're searching搜索,
we're finding發現 amazing驚人 things.
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當我們探索,我們就發現奇妙的事物。
00:54
But I want to tell you
about an amazing驚人 thing here on Earth地球.
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但今天我想告訴你們一件關於地球的奇妙的事,就是---
00:59
And that is that every一切 minute分鐘,
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每分鐘內,
01:01
400 pounds英鎊 of hydrogen
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四百磅的氫氣
01:04
and almost幾乎 seven pounds英鎊 of helium
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和將近七磅的氦氣
01:06
escape逃逸 from Earth地球 into space空間.
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正在從地球洩漏到宇宙中。
01:10
And this is gas加油站 that is going off
and never coming未來 back.
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這些氣體一去不復返。
01:15
So hydrogen, helium and many許多 other things
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氫氣、氮氣、和很多其他氣體
01:18
make up what's known已知
as the Earth's地球 atmosphere大氣層.
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共同組成了我們所知的地球大氣。
01:21
The atmosphere大氣層 is just these gases氣體
that form形成 a thin blue藍色 line
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大氣層從國際空間站的視角來看,
01:25
that's seen看到 here from
the International國際 Space空間 Station,
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就只是一層薄薄的藍色。
01:28
a photograph照片 that some astronauts宇航員 took.
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這是宇航員拍下的照片。
01:31
And this tenuous纖細 veneer單板 around our planet行星
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正是這層稀薄的大氣,
01:34
is what allows允許 life to flourish繁榮.
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讓地球上的生命欣欣向榮。
01:36
It protects保護 our planet行星
from too many許多 impacts影響,
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大氣保護地球,免受太多侵害,
01:39
from meteorites隕石 and the like.
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例如隕石墜落。
01:41
And it's such這樣 an amazing驚人 phenomenon現象
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但是事實上,
01:45
that the fact事實 that it's disappearing消失
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這個奇妙的現象正在消失。
01:48
should frighten嚇唬 you,
at least最小 a little bit.
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這應該讓你感到害怕,哪怕只是一點點。
01:52
So this process處理 is something that I study研究
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這消失的過程就是我研究的領域——
01:55
and it's called atmospheric大氣的 escape逃逸.
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“大氣逃離”。
01:58
So atmospheric大氣的 escape逃逸
is not specific具體 to planet行星 Earth地球.
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“大氣逃離”的現象不僅僅發生在地球上;
02:03
It's part部分 of what it means手段
to be a planet行星, if you ask me,
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這個現象是被稱為“行星”的條件之一,
02:07
because planets行星, not just here on Earth地球
but throughout始終 the universe宇宙,
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因為不僅在地球上,在宇宙中的所有行星上,
02:11
can undergo經歷 atmospheric大氣的 escape逃逸.
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都會發生“大氣逃離”現象。
02:14
And the way it happens發生 actually其實 tells告訴 us
about planets行星 themselves他們自己.
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實際上,這個現象可以告訴我們關於行星本身。
02:19
Because when you think
about the solar太陽能 system系統,
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因為當你想到太陽系,
02:22
you might威力 think about this picture圖片 here.
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你可能會想到這張圖片。
02:25
And you would say, well,
there are eight planets行星, maybe nine.
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你可能會說:這有八顆行星,可能是九顆。
02:29
So for those of you
who are stressed強調 by this picture圖片,
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那些為這張圖片感到苦惱的朋友,
02:31
I will add somebody for you.
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我要給你們加上一顆。
02:33
(Laughter笑聲)
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(笑)
02:34
Courtesy禮貌 of New Horizons地平線,
we're including包含 Pluto冥王星.
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我們尊重“新視野號",所以連冥王星也算上。
02:38
And the thing here is,
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我們現在討論的是:
02:39
for the purposes目的 of this talk
and atmospheric大氣的 escape逃逸,
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為了關於“大氣逃離”的研究課題,
02:42
Pluto冥王星 is a planet行星 in my mind心神,
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我認為冥王星屬於行星。
02:44
in the same相同 way that planets行星
around other stars明星 that we can't see
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同樣的,在我們看不見的恒星周圍
02:48
are also planets行星.
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公轉的行星都應該被稱作“行星”。
02:49
So fundamental基本的 characteristics特點 of planets行星
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因此,行星的基本特徵
02:52
include包括 the fact事實 that they are bodies身體
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包括他們受萬有引力吸引而凝聚成一體
02:55
that are bound together一起 by gravity重力.
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的這個事實。
02:57
So it's a lot of material材料
just stuck卡住 together一起
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這股吸引力令很多物質
03:00
with this attractive有吸引力 force.
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凝聚在一起。
03:02
And these bodies身體 are so big
and have so much gravity重力.
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因為這些行星體積巨大而且引力很強,
03:05
That's why they're round回合.
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所以它們是球體狀。
03:06
So when you look at all of these,
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所以當你看到圖中所示的所有星球,
03:08
including包含 Pluto冥王星,
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包括冥王星,
03:09
they're round回合.
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它們都是球體。
03:11
So you can see that gravity重力
is really at play here.
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萬有引力是一個很重要的因素。
03:13
But another另一個 fundamental基本的
characteristic特性 about planets行星
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行星的另一個基本特征
03:17
is what you don't see here,
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是你在這個圖裏沒有看到的,
03:18
and that's the star, the Sun太陽,
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那就是我們的恒星——太陽。
03:21
that all of the planets行星
in the solar太陽能 system系統 are orbiting軌道 around.
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太陽系中所有行星都圍繞著太陽公轉,
03:25
And that's fundamentally從根本上 driving主動
atmospheric大氣的 escape逃逸.
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這也是“大氣逃離”現象的基本原因。
03:29
The reason原因 that fundamentally從根本上 stars明星
drive駕駛 atmospheric大氣的 escape逃逸 from planets行星
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恒星造成大氣從行星中逃離是因為
03:35
is because stars明星 offer提供 planets行星
particles粒子 and light and heat
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恒星為行星提供的微粒、光、和熱
03:40
that can cause原因 the atmospheres氣氛 to go away.
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會促使大氣逃離。
03:43
So if you think of a hot-air熱氣 balloon氣球,
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你可以想象一個熱氣球,
03:45
or you look at this picture圖片
of lanterns燈籠 in Thailand泰國 at a festival,
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或者看看這幅泰國水燈節的照片,
03:49
you can see that hot air空氣
can propel推進 gasses氣體 upward向上.
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你會見到熱空氣可以驅使氣體上升。
03:53
And if you have enough足夠 energy能源 and heating加熱,
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如果能量和熱量充足,
03:55
which哪一個 our Sun太陽 does,
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像太陽那樣,
03:56
that gas加油站, which哪一個 is so light
and only bound by gravity重力,
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那麽質量輕而且受到引力吸引的氣體
04:00
it can escape逃逸 into space空間.
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就會逃離進入宇宙,
04:03
And so this is what's actually其實
causing造成 atmospheric大氣的 escape逃逸
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造成“大氣逃離”
04:07
here on Earth地球 and also on other planets行星 --
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不僅在地球,而且在其他行星上,
04:10
that interplay相互作用
between之間 heating加熱 from the star
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這互相作用都因恒星給予的熱量
04:13
and overcoming克服 the force
of gravity重力 on the planet行星.
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和掙脫行星自身的引力而產生。
04:17
So I've told you that it happens發生
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我曾經提到過:
04:18
at the rate of 400 pounds英鎊
a minute分鐘 for hydrogen
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氣體逃離的速度是每分鐘四百磅的氫氣
04:22
and almost幾乎 seven pounds英鎊 for helium.
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和將近七磅的氦氣,
04:25
But what does that look like?
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但這現象看起來是什麽樣子的呢?
04:26
Well, even in the '80s,
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從八十年代開始,
04:28
we took pictures圖片 of the Earth地球
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美國國家航空航天局使用
04:30
in the ultraviolet紫外線
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動態探測器飛船
04:31
using運用 NASA's美國航空航天局 Dynamic動態 Explorer探險者 spacecraft宇宙飛船.
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來為地球拍攝紫外線照片。
04:34
So these two images圖片 of the Earth地球
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這兩張照片告訴你
04:36
show顯示 you what that glow輝光
of escaping逃逸 hydrogen looks容貌 like,
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氫氣逃離時的光是什麽樣的——
04:40
shown顯示 in red.
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是紅色的那部分。
04:41
And you can also see other features特徵
like oxygen and nitrogen
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你也可以看到其他部分:
04:45
in that white白色 glimmer微光
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氧氣和氮氣是白色的、
04:46
in the circle showing展示 you the auroras極光
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發亮的圓圈的那部分。
04:49
and also some wisps縷縷 around the tropics熱帶.
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還有回歸線附近的小束光線。
04:52
So these are pictures圖片
that conclusively確鑿 show顯示 us
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所以總結來看,
04:55
that our atmosphere大氣層 isn't just
tightly緊緊 bound to us here on Earth地球
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我們的大氣層並不是只與地球緊密相連的,
04:58
but it's actually其實
reaching到達 out far into space空間,
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它們用,我會說是驚人的速度,
05:02
and at an alarming驚人 rate, I might威力 add.
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逃離到宇宙深處。
05:05
But the Earth地球 is not alone單獨
in undergoing經歷 atmospheric大氣的 escape逃逸.
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但地球並非唯一存在“大氣逃離”現象的行星,
05:08
Mars火星, our nearest最近的 neighbor鄰居,
is much smaller than Earth地球,
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我們最近的鄰居火星比地球小得多,
05:12
so it has much less gravity重力
with which哪一個 to hold保持 on to its atmosphere大氣層.
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所以它對於它的大氣層具有較小的引力。
05:16
And so even though雖然 Mars火星 has an atmosphere大氣層,
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所以盡管火星有大氣層,
05:18
we can see it's much thinner更薄
than the Earth's地球.
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火星大氣層比地球大氣層薄得多。
05:20
Just look at the surface表面.
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火星表面的大坑就可以告訴我們:
05:22
You see craters隕石坑 indicating說明
that it didn't have an atmosphere大氣層
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火星並沒有一層
05:25
that could stop those impacts影響.
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足以阻止大氣逃離的大氣。
05:27
Also, we see that it's the "red planet行星,"
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火星被稱為“紅色行星”,
05:30
and atmospheric大氣的 escape逃逸 plays播放 a role角色
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而“大氣逃離”
05:32
in Mars火星 being存在 red.
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是火星呈紅色的原因之一。
05:34
That's because we think
Mars火星 used to have a wetter多雨 past過去,
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火星原本是濕潤的,
05:38
and when water had enough足夠 energy能源,
it broke打破 up into hydrogen and oxygen,
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當水擁有了足夠能量就會分解成氫氣和氧氣,
05:42
and hydrogen being存在 so light,
it escaped逃脫 into space空間,
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質量很輕的氫氣逃離了火星,
05:46
and the oxygen that was left
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剩下來的氧氣
05:48
oxidized氧化 or rusted生鏽 the ground地面,
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氧化了土地,
05:50
making製造 that familiar
rusty生疏 red color顏色 that we see.
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使土地變成我們所看到的生銹的紅色。
05:54
So it's fine to look at pictures圖片 of Mars火星
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看到火星的照片,
05:56
and say that atmospheric大氣的 escape逃逸
probably大概 happened發生,
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我們就可以推斷“大氣逃離”現象的存在。
05:59
but NASANASA has a probe探測 that's currently目前
at Mars火星 called the MAVENMAVEN satellite衛星,
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美國國家航空航天局在火星上放置的MAVEN衛星,
06:03
and its actual實際 job工作
is to study研究 atmospheric大氣的 escape逃逸.
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它的實際任務就是研究“大氣逃離”現象。
06:07
It's the Mars火星 Atmosphere大氣層
and Volatile揮發物 Evolution演化 spacecraft宇宙飛船.
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MAVEN是“火星大氣和不穩定的演變”的縮寫。
06:11
And results結果 from it have already已經
shown顯示 pictures圖片 very similar類似
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它發現火星的“大氣逃離”現象
06:15
to what you've seen看到 here on Earth地球.
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與地球上發生的很相似。
06:17
We've我們已經 long known已知 that Mars火星
was losing失去 its atmosphere大氣層,
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我們一直知道火星正在失去它的大氣,
06:19
but we have some stunning令人驚嘆 pictures圖片.
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但讓我們來看看令人震驚的照片。
06:21
Here, for example,
you can see in the red circle
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比方說這裏,你可以看到紅色的圓圈
06:24
is the size尺寸 of Mars火星,
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代表火星的大小,
06:26
and in blue藍色 you can see the hydrogen
escaping逃逸 away from the planet行星.
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藍色的部分代表逃離火星的氫氣,
06:30
So it's reaching到達 out more than 10 times
the size尺寸 of the planet行星,
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而這塊藍色的區域是火星大小的十倍,
06:34
far enough足夠 away that it's
no longer bound to that planet行星.
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足以證明它們已經不再受到火星引力的吸引,
06:36
It's escaping逃逸 off into space空間.
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而是逃離進入了宇宙。
06:38
And this helps幫助 us confirm確認 ideas思路,
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這幫助我們證實了
06:41
like why Mars火星 is red,
from that lost丟失 hydrogen.
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火星呈紅色的原因是消失的氫氣。
06:44
But hydrogen isn't
the only gas加油站 that's lost丟失.
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但氫氣並非唯一逃離的氣體,
06:47
I mentioned提到 helium on Earth地球
and some oxygen and nitrogen,
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還有我之前提到地球上的氦氣、氧氣、和氮氣。
06:50
and from MAVENMAVEN we can also look
at the oxygen being存在 lost丟失 from Mars火星.
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我們還可以通過MAVEN衛星了解火星上消失的氧氣。
06:54
And you can see
that because oxygen is heavier較重,
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你可以看到,因為氧氣質量重,
06:56
it can't get as far as the hydrogen,
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它們不能像氫氣一樣逃離得那麽遠,
06:59
but it's still escaping逃逸
away from the planet行星.
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但它們仍在逃離火星。
07:01
You don't see it all confined受限
into that red circle.
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圖中綠色的部分不局限在紅色的圓圈以內。
07:05
So the fact事實 that we not only see
atmospheric大氣的 escape逃逸 on our own擁有 planet行星
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因此,我們不僅研究地球上的“大氣逃離”現象,
07:09
but we can study研究 it elsewhere別處
and send發送 spacecraft宇宙飛船
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還研究其他行星,並且通過發射飛船
07:13
allows允許 us to learn學習
about the past過去 of planets行星
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我們可以得知行星的歷史、
07:16
but also about planets行星 in general一般
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行星的一般特征、
07:18
and Earth's地球 future未來.
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以及地球的未來。
07:20
So one way we actually其實
can learn學習 about the future未來
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我們能預測未來的一個途徑,
07:23
is by planets行星 so far away
that we can't see.
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是通過我們看不見的遙遠行星。
07:27
And I should just note注意 though雖然,
before I go on to that,
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在我繼續講下去之前,我要告訴你們的是,
07:30
I'm not going to show顯示 you
photos相片 like this of Pluto冥王星,
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我沒有其他行星的類似圖片,
07:33
which哪一個 might威力 be disappointing令人失望,
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這可能會令你們失望,
07:34
but that's because we don't have them yet然而.
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这是因为我們還沒能拍攝到這樣的照片。
07:36
But the New Horizons地平線 mission任務
is currently目前 studying研究 atmospheric大氣的 escape逃逸
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但是“新視野”目前正在研究
07:39
being存在 lost丟失 from the planet行星.
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“大氣逃離”,
07:41
So stay tuned調整 and look out for that.
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所以你們不久之後就能看到。
07:43
But the planets行星
that I did want to talk about
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我想介紹的行星
07:45
are known已知 as transiting過境 exoplanets系外行星.
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叫作“淩日系外行星”。
07:48
So any planet行星 orbiting軌道 a star
that's not our Sun太陽
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凡是圍繞除太陽外的其他恒星公轉的行星,
07:51
is called an exoplanet太陽系外行星,
or extrasolar太陽系 planet行星.
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都被稱為“外行星”或者“太陽系外行星”。
07:54
And these planets行星 that we call transiting過境
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我們之所以稱它們為“淩”日系外行星,
07:57
have the special特別 feature特徵
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是因為它們的特殊特征:
07:58
that if you look
at that star in the middle中間,
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你看圖中間的那顆恒星,
08:00
you'll你會 see that actually其實 it's blinking閃爍.
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它實際上正在閃爍,
08:03
And the reason原因 that it's blinking閃爍
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而它閃爍的原因是
08:04
is because there are planets行星
that are going past過去 it all the time,
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一直有行星在圍繞它公轉,
08:09
and it's at special特別 orientation方向
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而且行星們公轉的特殊方向
08:11
where the planets行星 are blocking閉塞
the light from the star
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導致它們擋住了恒星的光芒,
08:13
that allows允許 us to see that light blinking閃爍.
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所以我們才能看到閃爍的光芒。
08:16
And by surveying測量學 the stars明星
in the night sky天空
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通過研究夜空中的星星
08:19
for this blinking閃爍 motion運動,
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閃爍的現象,
08:21
we are able能夠 to find planets行星.
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我們就能找到行星。
08:22
This is how we've我們已經 now been able能夠
to detect檢測 over 5,000 planets行星
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這是我們能夠在銀河系中
找到超過五千顆行星的方法,
08:27
in our own擁有 Milky乳白色 Way,
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08:28
and we know there are
many許多 more out there, like I mentioned提到.
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我們也知道還有更多等待被發現的行星存在。
當我們看到恒星的光芒時,
08:31
So when we look at the light
from these stars明星,
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我們看到的,如我所言,並不是恒星本身,
08:34
what we see, like I said,
is not the planet行星 itself本身,
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08:37
but you actually其實 see
a dimming調光 of the light
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而是瞬間減弱的光,
08:39
that we can record記錄 in time.
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我們可以記錄這段時間。
08:41
So the light drops滴劑 as the planet行星
decreases降低 in front面前 of the star,
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當行星公轉到恒星前方時,光線變暗,
08:44
and that's that blinking閃爍
that you saw before.
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這就是我們看到的閃爍的光芒。
08:47
So not only do we detect檢測 the planets行星
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我們不僅能夠發現行星,
08:49
but we can look at this light
in different不同 wavelengths波長.
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還可以看到光的不同波長。
08:52
So I mentioned提到 looking at the Earth地球
and Mars火星 in ultraviolet紫外線 light.
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我曾經提到通過紫外線觀測地球和火星,
08:56
If we look at transiting過境 exoplanets系外行星
with the Hubble哈勃 Space空間 Telescope望遠鏡,
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如果我們用哈勃望遠鏡觀測“淩日系外行星”,
08:59
we find that in the ultraviolet紫外線,
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我們能發現:在紫外線下
09:01
you see much bigger blinking閃爍,
much less light from the star,
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可以看到更強的閃爍,以及行星經過時
09:05
when the planet行星 is passing通過 in front面前.
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恒星散發出的更少的光芒。
09:07
And we think this is because you have
an extended擴展 atmosphere大氣層 of hydrogen
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這個現象的原因是:在行星周圍
09:10
all around the planet行星
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有一層被延伸了的氫氣層,
09:12
that's making製造 it look puffierpuffier
192
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這使得它看上去更厚,
09:13
and thus從而 blocking閉塞
more of the light that you see.
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所以擋住了更多的光。
09:16
So using運用 this technique技術,
we've我們已經 actually其實 been able能夠 to discover發現
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利用這個方法,我們已經成功發現了
09:19
a few少數 transiting過境 exoplanets系外行星
that are undergoing經歷 atmospheric大氣的 escape逃逸.
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一些有著“大氣逃離”現象的“淩日系外行星”,
09:24
And these planets行星
can be called hot Jupiters木星,
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它們其中的一些
09:26
for some of the ones那些 we've我們已經 found發現.
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被稱為“熱木星”,
09:28
And that's because
they're gas加油站 planets行星 like Jupiter木星,
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這是因為它們是類似木星一樣的氣體行星,
09:31
but they're so close to their star,
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但它們離恒星更近,
09:32
about a hundred times closer接近 than Jupiter木星.
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大約比木星離太陽的距離短一百倍。
09:35
And because there's all this
lightweight輕量級 gas加油站 that's ready準備 to escape逃逸,
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由於這些質輕氣體已經準備好要逃離,
09:38
and all this heating加熱 from the star,
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加上來自恒星的熱量,
09:40
you have completely全然 catastrophic災難性的 rates利率
of atmospheric大氣的 escape逃逸.
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“大氣逃離”的速度之快是災難性的。
09:44
So unlike不像 our 400 pounds英鎊 per minute分鐘
of hydrogen being存在 lost丟失 on Earth地球,
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不同於地球上每分鐘四百磅氫氣的逃離速度,
09:48
for these planets行星,
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在這些行星上,
09:50
you're losing失去 1.3 billion十億
pounds英鎊 of hydrogen every一切 minute分鐘.
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每分鐘有十三億磅氫氣消失。
09:55
So you might威力 think, well,
does this make the planet行星 cease停止 to exist存在?
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你可能會問:“大氣逃離”會讓行星滅亡嗎?
09:59
And this is a question
that people wondered想知道
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這是很多人想問的問題。
10:01
when they looked看著 at our solar太陽能 system系統,
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因為在我們的太陽系中,
10:03
because planets行星
closer接近 to the Sun太陽 are rocky岩石,
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離太陽近的行星都是佈滿岩石的,
10:05
and planets行星 further進一步 away
are bigger and more gaseous.
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而離太陽遠的行星更大而且有更多氣體。
10:08
Could you have started開始
with something like Jupiter木星
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毀滅不會先從離太陽近的木星
10:11
that was actually其實 close to the Sun太陽,
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先開始嗎?
10:13
and get rid擺脫 of all the gas加油站 in it?
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通過把木星上的所有氣體都排盡。
10:14
We now think that if you start開始
with something like a hot Jupiter木星,
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我們認為如果從“熱木星”這類行星開始,
10:17
you actually其實 can't end結束 up
with Mercury or the Earth地球.
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最後並不能以水星或者地球結束。
10:20
But if you started開始 with something smaller,
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但如果從更小的行星開始,
10:22
it's possible可能 that enough足夠 gas加油站
would have gotten得到 away
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足夠的氣體消失幹凈是有可能的,
10:25
that it would have
significantly顯著 impacted影響 it
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而那樣會對這顆行星造成巨大的影響,
10:27
and left you with something very different不同
than what you started開始 with.
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而且最後的結果可能跟開始時完全不同。
10:31
So all of this sounds聲音 sort分類 of general一般,
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這些聽起來都很籠統,
10:33
and we might威力 think about the solar太陽能 system系統,
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我們可能會聯想到太陽系,
10:35
but what does this have to do
with us here on Earth地球?
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但這和我們的地球有什麽關系?
10:38
Well, in the far future未來,
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在很遠的未來,
10:40
the Sun太陽 is going to get brighter光明.
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太陽將會變得更亮,
10:42
And as that happens發生,
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當這樣的情況發生時,
10:43
the heating加熱 that we find from the Sun太陽
is going to become成為 very intense激烈.
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太陽散發出的熱量將會劇增。
10:47
In the same相同 way that you see
gas加油站 streaming off from a hot Jupiter木星,
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如同我們看到氣體從“熱木星”上逃離那樣,
10:51
gas加油站 is going to stream off from the Earth地球.
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氣體也會從地球上蒸發。
10:54
And so what we can look forward前鋒 to,
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所以我們能夠預測的,
10:56
or at least最小 prepare準備 for,
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至少能夠有所準備的是:
10:58
is the fact事實 that in the far future未來,
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地球將在很遠的未來
11:00
the Earth地球 is going to look more like Mars火星.
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變得如同火星一般。
11:03
Our hydrogen, from water
that is broken破碎 down,
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從水分解出來的氫氣
11:06
is going to escape逃逸
into space空間 more rapidly急速,
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將會以更快的速度逃離地球,
11:08
and we're going to be left
with this dry, reddish planet行星.
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而留給我們的將是一個幹燥而泛紅的地球。
11:12
So don't fear恐懼, it's not
for a few少數 billion十億 years年份,
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別害怕,這離我們還有幾百萬年的時間,
11:15
so there's some time to prepare準備.
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我們還有足夠的時間準備。
11:17
(Laughter笑聲)
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(笑)
11:18
But I wanted you
to be aware知道的 of what's going on,
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但是我想讓你們知道的是正在發生的事。
11:21
not just in the future未來,
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“大氣逃離”並不是將發生在未來,
11:22
but atmospheric大氣的 escape逃逸
is happening事件 as we speak說話.
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而是發生在此時此刻的每分每秒。
11:25
So there's a lot of amazing驚人 science科學
that you hear about happening事件 in space空間
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很多奇妙的科學現象發生在宇宙,
11:29
and planets行星 that are far away,
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和離我們遙遠的行星中,
11:31
and we are studying研究 these planets行星
to learn學習 about these worlds世界.
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而我們通過研究這些行星來了解世界。
11:34
But as we learn學習 about Mars火星
or exoplanets系外行星 like hot Jupiters木星,
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但當我們研究到火星或是“熱木星”那樣的外行星時,
11:38
we find things like atmospheric大氣的 escape逃逸
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我們發現了“大氣逃離”的現象,
11:42
that tell us a lot more
about our planet行星 here on Earth地球.
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這告訴我們更多關於地球的信息。
11:45
So consider考慮 that the next下一個 time
you think that space空間 is far away.
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所以下次當你認為宇宙離我們很遠時,請別忘了發生在那裏和這裏的事。
11:49
Thank you.
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謝謝。
11:51
(Applause掌聲)
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(鼓掌)
Translated by Veronica Huang
Reviewed by Celine Wingki Law

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ABOUT THE SPEAKER
Anjali Tripathi - Astrophysicist
Anjali Tripathi explores planets to uncover the processes that make and destroy them.

Why you should listen

Even though Anjali Tripathi worked on NASA's Mars rovers in high school, the California native never expected to become an astronomer. Unlike the earthquakes she researched early on, astronomy seemed unconnected from daily life. As she has since discovered, exploring distant planets has a lot to do with life itself -- including the fate of the air we breathe. Using some of the most powerful telescopes and supercomputers, Tripathi studies how seemingly permanent planets change over time. She has pioneered the characterization of planet-forming environments and developed computer simulations to trace the 3D structure of planet atmospheres that are shrinking due to evaporation.

A natural teacher, Tripathi makes complex science concepts relevant and easy to understand. She believes that everyone can understand science -- even rocket science. She has partnered with the Smithsonian, Teach for America and others to increase scientific literacy and spread enthusiasm for the subject. Her engaging and humorous talks feature real world connections and unusual props, including a fully functioning Mars Pathfinder rover or full-size solar car.

Tripathi earned degrees in physics and astronomy from M.I.T., the University of Cambridge and Harvard University. Recognized as a promising American leader with a commitment to public service, Tripathi is a 2016-17 White House Fellow.


More profile about the speaker
Anjali Tripathi | Speaker | TED.com

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