Why Earth may someday look like Mars | Anjali Tripathi

112,549 views ใƒป 2017-01-19

TED


์•„๋ž˜ ์˜๋ฌธ์ž๋ง‰์„ ๋”๋ธ”ํด๋ฆญํ•˜์‹œ๋ฉด ์˜์ƒ์ด ์žฌ์ƒ๋ฉ๋‹ˆ๋‹ค.

00:00
Translator: Joseph Geni Reviewer: Joanna Pietrulewicz
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๋ฒˆ์—ญ: Jeongmin Kim ๊ฒ€ํ† : Katherine Cho
00:12
So when you look out at the stars at night,
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๋ฐคํ•˜๋Š˜์„ ๋ฐ”๋ผ๋ณด๋ฉด ๋ณด์ด๋Š” ํ’๊ฒฝ์€
00:15
it's amazing what you can see.
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๋„ˆ๋ฌด๋‚˜ ๋†€๋ž์Šต๋‹ˆ๋‹ค.
00:17
It's beautiful.
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์ •๋ง ์•„๋ฆ„๋‹ต์ฃ .
00:18
But what's more amazing is what you can't see,
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ํ•˜์ง€๋งŒ ๋”์šฑ ๋†€๋ผ์šด ๊ฒƒ์€ ๋ณด์ด์ง€ ์•Š๋Š” ๊ฒƒ๋“ค์ž…๋‹ˆ๋‹ค.
00:21
because what we know now
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์™œ๋ƒํ•˜๋ฉด ์šฐ๋ฆฌ๊ฐ€ ์ง€๊ธˆ ์•Œ๊ณ  ์žˆ๋‹ค์‹œํ”ผ
00:23
is that around every star or almost every star,
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๊ฑฐ์˜ ๋ชจ๋“  ๋ณ„ ์ฃผ๋ณ€์—๋Š”
00:26
there's a planet,
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ํ–‰์„ฑ์ด ๋ช‡ ๊ฐœ ๋Œ๊ณ  ์žˆ์ฃ .
00:27
or probably a few.
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00:30
So what this picture isn't showing you
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์ด ์‚ฌ์ง„์— ๋ณด์ด์ง€๋Š” ์•Š์ง€๋งŒ
00:32
are all the planets that we know about
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์šฐ๋ฆฌ๊ฐ€ ์•Œ๊ณ  ์žˆ๋Š” ์ˆ˜๋งŽ์€ ํ–‰์„ฑ๋“ค์ด
00:34
out there in space.
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์šฐ์ฃผ ์ €ํŽธ์— ์กด์žฌํ•ฉ๋‹ˆ๋‹ค.
00:36
But when we think about planets, we tend to think of faraway things
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ํ–‰์„ฑ์ด๋ผ๊ณ  ํ•˜๋ฉด ๋ณดํ†ต ์šฐ๋ฆฌ๊ฐ€ ์‚ฌ๋Š” ๊ณณ๊ณผ๋Š” ๋‹ค๋ฅธ
00:39
that are very different from our own.
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์™ธ๊ณ„์˜ ๋ฌด์–ธ๊ฐ€๋ฅผ ๋– ์˜ฌ๋ฆฝ๋‹ˆ๋‹ค.
00:41
But here we are on a planet,
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ํ•˜์ง€๋งŒ ์šฐ๋ฆฌ๋„ ํ–‰์„ฑ์— ์‚ด๊ณ  ์žˆ๊ณ 
00:43
and there are so many things that are amazing about Earth
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์ง€๊ตฌ๋Š” ํ–‰์„ฑ์œผ๋กœ์„œ ๋†€๋ผ์šด ๋ฉด๋ชจ๊ฐ€ ๋งŽ๊ธฐ์—
00:47
that we're searching far and wide to find things that are like that.
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์šฐ๋ฆฌ๋Š” ์šฐ์ฃผ ์–ด๋”˜๊ฐ€ ์ง€๊ตฌ์™€ ๋‹ฎ์€ ํ–‰์„ฑ์„ ์ฐพ๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค.
00:51
And when we're searching, we're finding amazing things.
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์ฐพ๋‹ค ๋ณด๋ฉด ๋†€๋ผ์šด ๊ฒƒ๋“ค์„ ๋ฐœ๊ฒฌํ•  ๋•Œ๊ฐ€ ์žˆ์ฃ .
00:54
But I want to tell you about an amazing thing here on Earth.
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ํ•˜์ง€๋งŒ ์˜ค๋Š˜ ๋งํ•˜๋ ค๋Š” ๊ฒƒ์€ ์ง€๊ตฌ์— ๋Œ€ํ•œ ๋†€๋ผ์šด ์‚ฌ์‹ค์ž…๋‹ˆ๋‹ค.
00:59
And that is that every minute,
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๊ทธ๊ฒƒ์€ ์ง€๊ตฌ์—์„œ 1๋ถ„๋งˆ๋‹ค
01:01
400 pounds of hydrogen
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400ํŒŒ์šด๋“œ(180kg)์˜ ์ˆ˜์†Œ์™€
01:04
and almost seven pounds of helium
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7ํŒŒ์šด๋“œ(3kg)๊ฐ€๋Ÿ‰์˜ ํ—ฌ๋ฅจ์ด
01:06
escape from Earth into space.
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์šฐ์ฃผ ๋ฐ–์œผ๋กœ ๋‚ ์•„๊ฐ„๋‹ค๋Š” ๊ฒƒ์ด์ฃ .
01:10
And this is gas that is going off and never coming back.
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ํ•œ๋ฒˆ ๋‚ ์•„๊ฐ„ ๊ธฐ์ฒด๋Š” ๋Œ์•„์˜ค์ง€ ์•Š์Šต๋‹ˆ๋‹ค.
01:15
So hydrogen, helium and many other things
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์ˆ˜์†Œ์™€ ํ—ฌ๋ฅจ, ๊ทธ๋ฆฌ๊ณ  ๋งŽ์€ ๋ฌผ์งˆ์ด
01:18
make up what's known as the Earth's atmosphere.
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์ง€๊ตฌ ๋Œ€๊ธฐ๋ฅผ ์กฐ์„ฑํ•˜๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค.
01:21
The atmosphere is just these gases that form a thin blue line
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์ด ๊ธฐ์ฒด๊ฐ€ ๋ชจ์ธ ์–‡์€ ํ‘ธ๋ฅธ ์„ ์ด
01:25
that's seen here from the International Space Station,
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๊ตญ์ œ์šฐ์ฃผ์ •๊ฑฐ์žฅ์—์„œ ํ•œ ์šฐ์ฃผ ๋น„ํ–‰์‚ฌ๊ฐ€ ์ฐ์€
01:28
a photograph that some astronauts took.
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๋Œ€๊ธฐ์˜ ๋ชจ์Šต์ž…๋‹ˆ๋‹ค.
01:31
And this tenuous veneer around our planet
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์ง€๊ตฌ๋ฅผ ๊ฐ์‹ธ๋Š” ์ด ์–‡์€ ์ธต ๋•๋ถ„์—
01:34
is what allows life to flourish.
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์ƒ๋ช…์ด ๋ฒˆ์„ฑํ•  ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.
01:36
It protects our planet from too many impacts,
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์œ ์„ฑ ๋“ฑ ์ˆ˜๋งŽ์€ ์ถฉ๋Œ๋กœ๋ถ€ํ„ฐ
01:39
from meteorites and the like.
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์šฐ๋ฆฌ๋ฅผ ๋ณดํ˜ธํ•ด ์ฃผ์ฃ .
01:41
And it's such an amazing phenomenon
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๋„ˆ๋ฌด๋‚˜๋„ ๋Œ€๋‹จํ•œ ํ˜„์ƒ์ด๋ผ์„œ
01:45
that the fact that it's disappearing
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์กฐ๊ธˆ์”ฉ ์‚ฌ๋ผ์ง„๋‹ค๊ณ  ํ•˜๋‹ˆ
01:48
should frighten you, at least a little bit.
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์•ฝ๊ฐ„ ์„ฌ๋œฉํ•˜์‹ค ๊ฒ๋‹ˆ๋‹ค.
01:52
So this process is something that I study
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์ œ๊ฐ€ ์—ฐ๊ตฌํ•˜๋Š” ์ด ํ˜„์ƒ์€
01:55
and it's called atmospheric escape.
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๋Œ€๊ธฐ ํƒˆ์ถœ์ž…๋‹ˆ๋‹ค.
01:58
So atmospheric escape is not specific to planet Earth.
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๋Œ€๊ธฐ ํƒˆ์ถœ์€ ์ง€๊ตฌ์—์„œ๋งŒ ์ผ์–ด๋‚˜๋Š” ๊ฒƒ์€ ์•„๋‹™๋‹ˆ๋‹ค.
02:03
It's part of what it means to be a planet, if you ask me,
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ํ–‰์„ฑ์ด ๊ฐ€์ง„ ์šด๋ช… ์ค‘ ํ•˜๋‚˜์ฃ .
02:07
because planets, not just here on Earth but throughout the universe,
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์ง€๊ตฌ ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ์ „ ์šฐ์ฃผ์˜ ๋ชจ๋“  ํ–‰์„ฑ์—์„œ
02:11
can undergo atmospheric escape.
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๋Œ€๊ธฐ ํƒˆ์ถœ์ด ๋ฐœ์ƒํ•ฉ๋‹ˆ๋‹ค.
02:14
And the way it happens actually tells us about planets themselves.
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๋Œ€๊ธฐ ํƒˆ์ถœ์ด ์ผ์–ด๋‚˜๋Š” ๊ณผ์ •์€ ์šฐ๋ฆฌ์—๊ฒŒ ํ–‰์„ฑ ์ž์ฒด์— ๋Œ€ํ•ด ์•Œ๋ ค์ค๋‹ˆ๋‹ค.
02:19
Because when you think about the solar system,
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ํƒœ์–‘๊ณ„๋ผ๊ณ  ํ•˜๋ฉด
02:22
you might think about this picture here.
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์ด๋Ÿฐ ์‚ฌ์ง„์ด ๋– ์˜ค๋ฅด์ฃ .
02:25
And you would say, well, there are eight planets, maybe nine.
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ํ–‰์„ฑ์ด ์—ฌ๋Ÿ ๊ฐœ ์žˆ๊ณ 
02:29
So for those of you who are stressed by this picture,
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์„ญ์„ญํ•˜์‹  ๋ถ„๋“ค์„ ์œ„ํ•ด
02:31
I will add somebody for you.
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ํ•˜๋‚˜๋ฅผ ๋”ํ•ด ๋“œ๋ฆด๊ฒŒ์š”.
02:33
(Laughter)
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(์›ƒ์Œ)
02:34
Courtesy of New Horizons, we're including Pluto.
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๋‰ด ํ˜ธ๋ผ์ด์ฆŒ ํ˜ธ๊ฐ€ ์ฐ์€ ๋ช…์™•์„ฑ์„ ์ถ”๊ฐ€ํ–ˆ์Šต๋‹ˆ๋‹ค.
02:38
And the thing here is,
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ํ•˜๋‚˜ ์งš๊ณ  ๋„˜์–ด๊ฐ€์ž๋ฉด
02:39
for the purposes of this talk and atmospheric escape,
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๋Œ€๊ธฐ ํƒˆ์ถœ์ด๋ผ๋Š” ์ฃผ์ œ์— ๊ด€ํ•ด์„œ๋Š”
02:42
Pluto is a planet in my mind,
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๋ช…์™•์„ฑ๋„
02:44
in the same way that planets around other stars that we can't see
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๋ณด์ด์ง€ ์•Š๋Š” ๋ณ„๋“ค ์ฃผ์œ„์˜ ํ–‰์„ฑ๋„ ๋ชจ๋‘ ๊ฐ™์€ ๋Œ€์ƒ์ด๋ผ๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.
02:48
are also planets.
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02:49
So fundamental characteristics of planets
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ํ–‰์„ฑ์˜ ๊ธฐ๋ณธ์ ์ธ ํŠน์„ฑ ์ค‘์—๋Š”
02:52
include the fact that they are bodies
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์ค‘๋ ฅ์— ์˜ํ•ด ๊ฒฐ์ง‘๋œ ๋ฌผ์ฒด๋ผ๋Š” ์กฐ๊ฑด์ด ์žˆ์ฃ .
02:55
that are bound together by gravity.
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02:57
So it's a lot of material just stuck together
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๊ฒฐ๊ตญ ์ด ๋Œ์–ด๋‹น๊ธฐ๋Š” ํž˜์— ์˜ํ•ด
03:00
with this attractive force.
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์—ฌ๋Ÿฌ ๋ฌผ์งˆ์ด ๋ฉ์–ด๋ฆฌ๋กœ ๋ญ‰์ณ ์žˆ๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.
03:02
And these bodies are so big and have so much gravity.
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์ฒœ์ฒด๊ฐ€ ๋งค์šฐ ํฌ๋‹ˆ๊นŒ ์ค‘๋ ฅ๋„ ํฌ๊ฒ ์ฃ .
03:05
That's why they're round.
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์ด๊ฒƒ์ด ํ–‰์„ฑ์ด ๋‘ฅ๊ทผ ์ด์œ ์ž…๋‹ˆ๋‹ค.
03:06
So when you look at all of these,
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๋ช…์™•์„ฑ์„ ํฌํ•จํ•ด์„œ ์ด๋Ÿฐ ๋Œ€์ƒ์„ ๋ณด๋ฉด
03:08
including Pluto,
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03:09
they're round.
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๋ชจ๋‘ ๋‘ฅ๊ธ€๊ณ 
03:11
So you can see that gravity is really at play here.
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์ค‘๋ ฅ์ด ์ž‘์šฉํ•˜๋Š” ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.
03:13
But another fundamental characteristic about planets
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ํ–‰์„ฑ์˜ ๋˜ ๋‹ค๋ฅธ ์ค‘์š”ํ•œ ์กฐ๊ฑด์€
03:17
is what you don't see here,
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์•„์ง ๋‚˜ํƒ€๋‚ด์ง€ ์•Š์€
03:18
and that's the star, the Sun,
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์ด ํƒœ์–‘์ด๋ผ๋Š” ํ–‰์„ฑ์˜ ์ฃผ๋ณ€์„
03:21
that all of the planets in the solar system are orbiting around.
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ํƒœ์–‘๊ณ„์˜ ๋ชจ๋“  ํ–‰์„ฑ์ด ๊ณต์ „ํ•œ๋‹ค๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.
03:25
And that's fundamentally driving atmospheric escape.
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๊ทธ๋ฆฌ๊ณ  ์ด๊ฒƒ์ด ๋Œ€๊ธฐ ํƒˆ์ถœ์„ ์ผ์œผํ‚ต๋‹ˆ๋‹ค.
03:29
The reason that fundamentally stars drive atmospheric escape from planets
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ํ•ญ์„ฑ์ด ํ–‰์„ฑ ๋Œ€๊ธฐ๋ฅผ ํƒˆ์ถœ์‹œํ‚ค๋Š” ์ด์œ ๋Š”
03:35
is because stars offer planets particles and light and heat
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ํ•ญ์„ฑ์ด ๋ฐœ์‚ฐํ•˜๋Š” ์ž…์ž์™€ ๋น›, ์—ด์ด
03:40
that can cause the atmospheres to go away.
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ํ–‰์„ฑ ๋Œ€๊ธฐ์— ๋‹ฟ๊ธฐ ๋•Œ๋ฌธ์ž…๋‹ˆ๋‹ค.
03:43
So if you think of a hot-air balloon,
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์—ด๊ธฐ๊ตฌ๋‚˜
03:45
or you look at this picture of lanterns in Thailand at a festival,
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ํƒœ๊ตญ์˜ ํ•œ ์ถ•์ œ์˜ ์ด ๋“ฑ๋ถˆ ์‚ฌ์ง„์„ ์˜ˆ๋กœ ๋“ค๋ฉด
03:49
you can see that hot air can propel gasses upward.
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๋œจ๊ฑฐ์šด ๊ณต๊ธฐ๊ฐ€ ๊ธฐ์ฒด๋ฅผ ์œ„๋กœ ํ–ฅํ•˜๊ฒŒ ํ•œ๋‹ค๋Š” ๊ฑธ ์•Œ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.
03:53
And if you have enough energy and heating,
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์—ด๊ณผ ์—๋„ˆ์ง€๊ฐ€ ์ถฉ๋ถ„ํžˆ ์ฃผ์–ด์ง€๋ฉด
03:55
which our Sun does,
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ํƒœ์–‘์ด ๊ทธ๋ฆฌ ํ•˜๋“ฏ์ด
03:56
that gas, which is so light and only bound by gravity,
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์ค‘๋ ฅ์ด ๊ฒจ์šฐ ๋ถ™๋“ค๊ณ  ์žˆ๋Š” ๊ฐ€๋ฒผ์šด ๊ธฐ์ฒด๋Š”
04:00
it can escape into space.
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์šฐ์ฃผ๋กœ ๋‚ ์•„๊ฐ€ ๋ฒ„๋ฆฝ๋‹ˆ๋‹ค.
04:03
And so this is what's actually causing atmospheric escape
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์ด๊ฒƒ์ด ์ง€๊ตฌ์™€ ๋‹ค๋ฅธ ํ–‰์„ฑ์—์„œ ๋Œ€๊ธฐ ํƒˆ์ถœ์ด ์ผ์–ด๋‚˜๋Š” ๊ณผ์ •์ž…๋‹ˆ๋‹ค.
04:07
here on Earth and also on other planets --
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04:10
that interplay between heating from the star
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ํ•ญ์„ฑ์—์„œ ์˜ค๋Š” ์—ด์ด
04:13
and overcoming the force of gravity on the planet.
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ํ–‰์„ฑ์˜ ์ค‘๋ ฅ๋ณด๋‹ค ๋” ํฐ ํž˜์„ ๋ฐœํœ˜ํ•˜๋Š” ๊ฒƒ์ด์ฃ .
04:17
So I've told you that it happens
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์•„๊นŒ ์ˆ˜์†Œ๋Š” ์ผ ๋ถ„์— 400ํŒŒ์šด๋“œ(180kg)
04:18
at the rate of 400 pounds a minute for hydrogen
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ํ—ฌ๋ฅจ์€ 7ํŒŒ์šด๋“œ(3kg)๋ผ๊ณ 
04:22
and almost seven pounds for helium.
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๋ง์”€๋“œ๋ ธ๋Š”๋ฐ
04:25
But what does that look like?
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์‹ค์ œ๋กœ๋Š” ์–ด๋–ป๊ฒŒ ๋ณด์ผ๊นŒ์š”?
04:26
Well, even in the '80s,
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๋ฌด๋ ค 80๋…„๋Œ€์— NASA์—์„œ
04:28
we took pictures of the Earth
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๋‹ค์ด๋‚˜๋ฏน ์ต์Šคํ”Œ๋กœ๋Ÿฌ ์œ„์„ฑ์œผ๋กœ
04:30
in the ultraviolet
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์ง€๊ตฌ ๋Œ€๊ธฐ์˜
04:31
using NASA's Dynamic Explorer spacecraft.
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์ž์™ธ์„  ์ดฌ์˜์„ ํ•˜์˜€์Šต๋‹ˆ๋‹ค.
04:34
So these two images of the Earth
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์ด ๋‘ ์ง€๊ตฌ ์‚ฌ์ง„์ด
04:36
show you what that glow of escaping hydrogen looks like,
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ํƒˆ์ถœํ•˜๋Š” ์ˆ˜์†Œ๊ฐ€ ๋‚ด๋ฟœ๋Š” ๋น›์„ ๋ถ‰์€์ƒ‰์œผ๋กœ ๋ณด์—ฌ ์ค๋‹ˆ๋‹ค.
04:40
shown in red.
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04:41
And you can also see other features like oxygen and nitrogen
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์‚ฐ์†Œ๋‚˜ ์งˆ์†Œ ๊ฐ™์€ ๋‹ค๋ฅธ ๊ฒƒ๋“ค๋„
04:45
in that white glimmer
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ํฌ๋ฏธํ•œ ํฐ ๋น›์œผ๋กœ
04:46
in the circle showing you the auroras
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๊ทน์ง€์˜ ์˜ค๋กœ๋ผ์™€
04:49
and also some wisps around the tropics.
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์—ด๋Œ€ ๋ถ€๋ถ„์˜ ๋น›์ค„๊ธฐ๋ฅผ ๋ณด์—ฌ ์ฃผ์ง€์š”.
04:52
So these are pictures that conclusively show us
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์ด ์‚ฌ์ง„์œผ๋กœ๋ถ€ํ„ฐ ์•Œ ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์€
04:55
that our atmosphere isn't just tightly bound to us here on Earth
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์šฐ๋ฆฌ ๋Œ€๊ธฐ๊ฐ€ ์ง€๊ตฌ์— ๋”ฑ ๋ถ™์–ด ์žˆ์ง€ ์•Š๊ณ 
04:58
but it's actually reaching out far into space,
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์ƒ๋‹นํ•œ ์†๋„๋กœ ์šฐ์ฃผ ๋ฐ–์œผ๋กœ
05:02
and at an alarming rate, I might add.
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๋ฉ€์–ด์ ธ๊ฐ€๊ณ  ์žˆ๋‹ค๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.
05:05
But the Earth is not alone in undergoing atmospheric escape.
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ํ•˜์ง€๋งŒ ์ง€๊ตฌ์—์„œ๋งŒ ๋Œ€๊ธฐ ํƒˆ์ถœ์ด ์ผ์–ด๋‚˜๋Š” ๊ฒƒ์€ ์•„๋‹ˆ์ฃ .
05:08
Mars, our nearest neighbor, is much smaller than Earth,
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์šฐ๋ฆฌ์˜ ์ด์›ƒ ํ–‰์„ฑ ํ™”์„ฑ์€ ์ง€๊ตฌ๋ณด๋‹ค ํ›จ์”ฌ ์ž‘์•„์„œ
05:12
so it has much less gravity with which to hold on to its atmosphere.
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๋Œ€๊ธฐ๋ฅผ ๋ถ™๋“ค๊ณ  ์žˆ์„ ์ค‘๋ ฅ์ด ๋” ์ž‘์Šต๋‹ˆ๋‹ค.
05:16
And so even though Mars has an atmosphere,
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ํ™”์„ฑ์—๋„ ๋Œ€๊ธฐ๊ฐ€ ์žˆ๊ธด ํ•˜์ง€๋งŒ
05:18
we can see it's much thinner than the Earth's.
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์ง€๊ตฌ๋ณด๋‹ค ํ›จ์”ฌ ํฌ๋ฐ•ํ•ฉ๋‹ˆ๋‹ค.
05:20
Just look at the surface.
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ํ‘œ๋ฉด์„ ๋ณด๋ฉด
05:22
You see craters indicating that it didn't have an atmosphere
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๋Œ€๊ธฐ๊ฐ€ ์ถฉ๋Œ๋ฌผ์„ ๋ง‰์„ ์ˆ˜ ์—†์–ด ์ˆ˜๋งŽ์€ ์ถฉ๋Œ๊ตฌ๋กœ
05:25
that could stop those impacts.
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์šธํ‰๋ถˆํ‰ํ•ด์ ธ ์žˆ์ฃ .
05:27
Also, we see that it's the "red planet,"
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๋˜ ํ™”์„ฑ์ด '๋ถ‰์€ ํ–‰์„ฑ'์ธ ๋ฐ๋Š”
05:30
and atmospheric escape plays a role
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๋Œ€๊ธฐ ํƒˆ์ถœ๋„ ํ•œ ๋ชซ ํ•˜๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค.
05:32
in Mars being red.
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05:34
That's because we think Mars used to have a wetter past,
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๊ณผํ•™์ž๋“ค์€ ํ™”์„ฑ์ด ์ด์ „์—๋Š” ๋ฌผ์ด ๋” ์žˆ์—ˆ์ง€๋งŒ
05:38
and when water had enough energy, it broke up into hydrogen and oxygen,
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๋ฌผ์ด ์—๋„ˆ์ง€๋ฅผ ๋ฐ›์•„ ์ˆ˜์†Œ์™€ ์‚ฐ์†Œ๋กœ ๋ถ„ํ•ด๋˜๊ณ 
05:42
and hydrogen being so light, it escaped into space,
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๊ฐ€๋ฒผ์šด ์ˆ˜์†Œ๊ฐ€ ์šฐ์ฃผ๋กœ ํƒˆ์ถœํ•œ ์‚ฌ์ด
05:46
and the oxygen that was left
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๋‚จ์€ ์‚ฐ์†Œ๋Š”
05:48
oxidized or rusted the ground,
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๋•…์„ ์‚ฐํ™”์‹œ์ผœ
05:50
making that familiar rusty red color that we see.
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์ง€๊ธˆ์˜ ๋…น์Šจ ๋ถ‰์€ ํ‘œ๋ฉด์„ ๋งŒ๋“ค์—ˆ๋‹ค๊ณ  ์ƒ๊ฐํ•ฉ๋‹ˆ๋‹ค.
05:54
So it's fine to look at pictures of Mars
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ํ™”์„ฑ ์‚ฌ์ง„๋งŒ ๋ณด๊ณ ๋„
05:56
and say that atmospheric escape probably happened,
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๋Œ€๊ธฐ ํƒˆ์ถœ์ด ์ผ์–ด๋‚œ ๊ฒƒ์„ ์ถ”์ธกํ•  ์ˆ˜ ์žˆ์ง€๋งŒ
05:59
but NASA has a probe that's currently at Mars called the MAVEN satellite,
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NASA๋Š” MAVEN ์œ„์„ฑ์„ ํ˜„์žฌ ํ™”์„ฑ์— ์ง์ ‘ ๋ณด๋‚ด
06:03
and its actual job is to study atmospheric escape.
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๋Œ€๊ธฐ ํƒˆ์ถœ ์—ฐ๊ตฌ ์ž„๋ฌด๋ฅผ ์ˆ˜ํ–‰์‹œ๊ธฐ๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค.
06:07
It's the Mars Atmosphere and Volatile Evolution spacecraft.
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๋จธ๋ฆฟ๊ธ€์ž๋Š” 'ํ™”์„ฑ ๋Œ€๊ธฐ ํœ˜๋ฐœ์„ฑ ์ง„ํ–‰' ์—์„œ ์™”์Šต๋‹ˆ๋‹ค.
06:11
And results from it have already shown pictures very similar
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ํƒ์‚ฌ ๊ฒฐ๊ณผ๋Š” ์ง€๊ตฌ์—์„œ ๋ณธ ๊ฒƒ๊ณผ ๋งค์šฐ ๋น„์Šทํ•œ ๋ชจ์Šต์„
06:15
to what you've seen here on Earth.
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๋‚˜ํƒ€๋‚ด๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค.
06:17
We've long known that Mars was losing its atmosphere,
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ํ™”์„ฑ์˜ ๋Œ€๊ธฐ ์†์‹ค์€ ์˜ค๋žซ๋™์•ˆ ์•Œ๊ณ  ์žˆ์—ˆ์ง€๋งŒ
06:19
but we have some stunning pictures.
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๋ช‡๋ช‡ ๋†€๋ผ์šด ์‚ฌ์ง„๋“ค์ด ์žˆ์Šต๋‹ˆ๋‹ค.
06:21
Here, for example, you can see in the red circle
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์—ฌ๊ธฐ๋ฅผ ๋ณด๋ฉด ๋ถ‰์€ ์›์œผ๋กœ ํ‘œ์‹œํ•œ ๋ถ€๋ถ„์ด
06:24
is the size of Mars,
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ํ™”์„ฑ ์˜์—ญ์ด๊ณ 
06:26
and in blue you can see the hydrogen escaping away from the planet.
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ํ‘ธ๋ฅธ์ƒ‰์€ ํ–‰์„ฑ์„ ํƒˆ์ถœํ•˜๋Š” ์ˆ˜์†Œ์ž…๋‹ˆ๋‹ค.
06:30
So it's reaching out more than 10 times the size of the planet,
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ํ–‰์„ฑ ํฌ๊ธฐ์˜ ์—ด ๋ฐฐ ์ด์ƒ ๋ฒ—์–ด๋‚ฌ์œผ๋‹ˆ
06:34
far enough away that it's no longer bound to that planet.
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๋” ์ด์ƒ ๋ถ™์žกํ˜€ ์žˆ์ง€ ์•Š๋‹ค๊ณ  ๋ณด์•„๋„ ๋˜๊ฒ ์ฃ .
06:36
It's escaping off into space.
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์šฐ์ฃผ๋กœ ํƒˆ์ถœํ•˜๋Š” ๊ฒ๋‹ˆ๋‹ค.
06:38
And this helps us confirm ideas,
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์ด ์‚ฌ์ง„์œผ๋กœ ํ™”์„ฑ์ด ๋ถ‰์€ ์ด์œ ๋ฅผ
06:41
like why Mars is red, from that lost hydrogen.
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์ˆ˜์†Œ ํƒˆ์ถœ ๋•Œ๋ฌธ์ด๋ผ๊ณ  ์„ค๋ช…ํ•  ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.
06:44
But hydrogen isn't the only gas that's lost.
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ํ•˜์ง€๋งŒ ์ˆ˜์†Œ๋งŒ ํƒˆ์ถœํ•˜๋Š” ๊ฒƒ์€ ์•„๋‹ˆ์ฃ .
06:47
I mentioned helium on Earth and some oxygen and nitrogen,
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์ง€๊ตฌ์—์„œ์ฒ˜๋Ÿผ ํ—ฌ๋ฅจ๊ณผ ์•ฝ๊ฐ„์˜ ์‚ฐ์†Œ, ์งˆ์†Œ๋„
06:50
and from MAVEN we can also look at the oxygen being lost from Mars.
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ํ–‰์„ฑ์„ ๋ฒ—์–ด๋‚˜๋Š” ๊ฒƒ์„ MAVEN ์‚ฌ์ง„์œผ๋กœ ํ™•์ธ ๊ฐ€๋Šฅํ•ฉ๋‹ˆ๋‹ค.
06:54
And you can see that because oxygen is heavier,
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์‚ฐ์†Œ๋Š” ๋” ๋ฌด๊ฒ๊ธฐ ๋•Œ๋ฌธ์—
06:56
it can't get as far as the hydrogen,
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์ˆ˜์†Œ๋งŒํผ ๋ฉ€๋ฆฌ ๊ฐ€์ง€๋Š” ์•Š์ง€๋งŒ
06:59
but it's still escaping away from the planet.
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์—ฌ์ „ํžˆ ํƒˆ์ถœ์„ ํ•˜๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค.
07:01
You don't see it all confined into that red circle.
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๋ถ‰์€ ์› ๋ฐ–์— ๊ธฐ์ฒด๊ฐ€ ์กด์žฌํ•˜์ง€์š”.
07:05
So the fact that we not only see atmospheric escape on our own planet
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์šฐ๋ฆฌ๊ฐ€ ์ง€๊ตฌ์˜ ๋Œ€๊ธฐ ํƒˆ์ถœ์„ ์—ฐ๊ตฌํ•˜๋Š” ๊ฒƒ์— ๋”ํ•ด์„œ
07:09
but we can study it elsewhere and send spacecraft
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๋‹ค๋ฅธ ํ–‰์„ฑ์— ์šฐ์ฃผ์„ ์„ ๋ณด๋‚ด ์—ฐ๊ตฌํ•  ์ˆ˜ ์žˆ๋Š” ์‚ฌ์‹ค์€
07:13
allows us to learn about the past of planets
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ํ–‰์„ฑ์˜ ๊ณผ๊ฑฐ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ
07:16
but also about planets in general
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ํ–‰์„ฑ์˜ ์ „๋ฐ˜์ ์ธ ๋ชจ์Šต, ๊ทธ๋ฆฌ๊ณ 
07:18
and Earth's future.
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์ง€๊ตฌ์˜ ๋ฏธ๋ž˜๋„ ์•Œ ์ˆ˜ ์žˆ๊ฒŒ ํ•ด์ค๋‹ˆ๋‹ค.
07:20
So one way we actually can learn about the future
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์šฐ๋ฆฌ์˜ ๋ฏธ๋ž˜๋ฅผ ์•Œ ์ˆ˜ ์žˆ๋Š” ํ‘œ๋ณธ์ด
07:23
is by planets so far away that we can't see.
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๋ณด์ด์ง€ ์•Š๋Š” ๋จผ ํ–‰์„ฑ์— ์žˆ๋‹ค๋Š” ๊ฒƒ์ด์ฃ .
07:27
And I should just note though, before I go on to that,
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๊ทธ ์ด์•ผ๊ธฐ๋ฅผ ํ•˜๊ธฐ ์ „์— ์‹ค๋ง์Šค๋Ÿฝ์ง€๋งŒ
07:30
I'm not going to show you photos like this of Pluto,
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๋ช…์™•์„ฑ ์‚ฌ์ง„์€ ๋ณด์—ฌ ๋“œ๋ฆฌ์ง€ ์•Š์„ ๊ฒƒ์ด๋ผ๋Š” ๊ฒƒ์„
07:33
which might be disappointing,
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๋งํ•ด ๋‘๋ ค ํ•ฉ๋‹ˆ๋‹ค.
07:34
but that's because we don't have them yet.
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์•„์ง ์ฐ์ง€ ๋ชปํ–ˆ์œผ๋‹ˆ๊นŒ์š”.
07:36
But the New Horizons mission is currently studying atmospheric escape
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๋‰ด ํ˜ธ๋ผ์ด์ฆŒ ํ˜ธ์˜ ์ž„๋ฌด๊ฐ€ ๋ช…์™•์„ฑ์—์„œ์˜ ๋Œ€๊ธฐ ํƒˆ์ถœ์„
07:39
being lost from the planet.
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์กฐ์‚ฌํ•˜๋Š” ๊ฒƒ์ด๋‹ˆ
07:41
So stay tuned and look out for that.
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๊ณ„์† ๊ด€์‹ฌ์„ ๊ธฐ์šธ์—ฌ ์ฃผ์„ธ์š”.
07:43
But the planets that I did want to talk about
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๋Œ€์‹  ์ œ๊ฐ€ ๋‹ค๋ฃจ๋ ค๋Š” ํ–‰์„ฑ์€
07:45
are known as transiting exoplanets.
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ํ†ต๊ณผ ์™ธํ–‰์„ฑ์ด๋ผ๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.
07:48
So any planet orbiting a star that's not our Sun
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ํƒœ์–‘์ด ์•„๋‹Œ ๋ณ„ ์ฃผ์œ„๋ฅผ ๊ณต์ „ํ•˜๋Š” ํ–‰์„ฑ์€
07:51
is called an exoplanet, or extrasolar planet.
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๋ชจ๋‘ ์™ธ๊ณ„ ํ–‰์„ฑ ๋˜๋Š” ํƒœ์–‘๊ณ„ ์™ธ ํ–‰์„ฑ์ž…๋‹ˆ๋‹ค.
07:54
And these planets that we call transiting
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๊ทธ๋ฆฌ๊ณ  ํ†ต๊ณผํ•œ๋‹ค๋Š” ๋ง์€
07:57
have the special feature
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๊ถค๋„์˜ ํŠน์„ฑ์ธ๋ฐ
07:58
that if you look at that star in the middle,
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์ค‘์•™์— ๋ณ„์„ ๋ณด๋ฉด
08:00
you'll see that actually it's blinking.
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๋ฐ˜์ง์ด๋Š” ๊ฒƒ์ด ๋ณด์ด์‹œ์ฃ .
08:03
And the reason that it's blinking
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๋ฐ˜์ง์ด๋Š” ์ด์œ ๋Š”
08:04
is because there are planets that are going past it all the time,
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ํ–‰์„ฑ์ด ๋•Œ๋กœ ๊ทธ๊ณณ์„ ์ง€๋‚˜๊ฐ€๋ฉด์„œ
08:09
and it's that special orientation
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๊ถค๋„๊ฐ€ ํŠน๋ณ„ํ•œ ์œ„์น˜์— ์žˆ์–ด
08:11
where the planets are blocking the light from the star
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ํ–‰์„ฑ์ด ํ•ญ์„ฑ์˜ ๋น›์„ ๋ง‰์•„
08:13
that allows us to see that light blinking.
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์šฐ๋ฆฌ์—๊ฒŒ ๋ฐ˜์ง์ด๊ฒŒ ๋ณด์ด๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.
08:16
And by surveying the stars in the night sky
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๋ฐคํ•˜๋Š˜์˜ ๋ณ„๋“ค์„ ๋ณด๋ฉฐ
08:19
for this blinking motion,
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์ด ๋ฐ˜์ง์ž„์„ ์กฐ์‚ฌํ•˜๋ฉด
08:21
we are able to find planets.
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ํ–‰์„ฑ์„ ์ฐพ์„ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.
08:22
This is how we've now been able to detect over 5,000 planets
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์ด๋ ‡๊ฒŒ ํ•ด์„œ ์šฐ๋ฆฌ ์€ํ•˜์—์„œ 5000๊ฐœ ์ด์ƒ์˜
08:27
in our own Milky Way,
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ํ–‰์„ฑ์„ ์ฐพ์•„๋‚ด์—ˆ์Šต๋‹ˆ๋‹ค.
08:28
and we know there are many more out there, like I mentioned.
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๋” ์ˆ˜๋งŽ์€ ํ–‰์„ฑ์ด ์กด์žฌํ•˜์ง€๋งŒ์š”.
08:31
So when we look at the light from these stars,
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์ด ํ–‰์„ฑ์—์„œ ์˜ค๋Š” ๋น›์„ ๋ณด์•˜์„ ๋•Œ
08:34
what we see, like I said, is not the planet itself,
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์ฃผ์‹œํ•˜๋Š” ๊ฒƒ์€ ๋น› ์ž์ฒด๊ฐ€ ์•„๋‹ˆ๋ผ
08:37
but you actually see a dimming of the light
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์ผ์ • ์‹œ๊ฐ„ ๋™์•ˆ ๋ฐ๊ธฐ๊ฐ€
08:39
that we can record in time.
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ํฌ๋ฏธํ•ด์ง€๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.
08:41
So the light drops as the planet decreases in front of the star,
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ํ–‰์„ฑ์ด ๋ณ„ ์•ž์„ ์ง„ํ–‰ํ•˜๋ฉด์„œ ๋ฐ๊ธฐ๊ฐ€ ์ค„์–ด๋“ค๊ณ 
08:44
and that's that blinking that you saw before.
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์ด๊ฒƒ์ด ์•„๊นŒ ๊ด€์ฐฐํ•œ ๊นœ๋นก์ž„์ž…๋‹ˆ๋‹ค.
08:47
So not only do we detect the planets
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๋‹จ์ˆœํžˆ ํ–‰์„ฑ์„ ์ฐพ์„ ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ
08:49
but we can look at this light in different wavelengths.
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ํŒŒ์žฅ๋ณ„๋กœ ๋น›์„ ๊ด€์ฐฐํ•  ์ˆ˜๋„ ์žˆ์Šต๋‹ˆ๋‹ค.
08:52
So I mentioned looking at the Earth and Mars in ultraviolet light.
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์ „์— ๋ณด์‹  ์‚ฌ์ง„ ์ค‘์— ์ง€๊ตฌ์™€ ํ™”์„ฑ์˜ ์ž์™ธ์„  ์‚ฌ์ง„์ด ์žˆ์—ˆ์ฃ .
08:56
If we look at transiting exoplanets with the Hubble Space Telescope,
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ํ†ต๊ณผ ์™ธํ–‰์„ฑ์„ ํ—ˆ๋ธ” ์šฐ์ฃผ ๋ง์›๊ฒฝ์œผ๋กœ ๊ด€์ธกํ•˜๋ฉด
08:59
we find that in the ultraviolet,
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์ž์™ธ์„  ์˜์—ญ์—์„œ
09:01
you see much bigger blinking, much less light from the star,
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ํ–‰์„ฑ์ด ์•ž์„ ์ง€๋‚˜๊ฐˆ ๋•Œ ํ›จ์”ฌ ํฌ๊ฒŒ
09:05
when the planet is passing in front.
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๋ฐ๊ธฐ๊ฐ€ ๋ณ€ํ•ฉ๋‹ˆ๋‹ค.
09:07
And we think this is because you have an extended atmosphere of hydrogen
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๊ณผํ•™์ž๋“ค์€ ์ด๊ฒƒ์ด ๋ฉ€๋ฆฌ ๋ป—์€ ์ˆ˜์†Œ ๋Œ€๊ธฐ์ธต์ด ํ–‰์„ฑ์„ ๊ฐ์‹ธ๋ฉด์„œ
09:10
all around the planet
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09:12
that's making it look puffier
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๊ตฌ๋ฆ„ ๊ฐ™์€ ์—ญํ• ๋กœ
09:13
and thus blocking more of the light that you see.
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๋” ๋งŽ์€ ๋น›์„ ๋ง‰๊ธฐ ๋•Œ๋ฌธ์ด๋ผ ์ถ”์ธกํ•ฉ๋‹ˆ๋‹ค.
09:16
So using this technique, we've actually been able to discover
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์ด ๊ธฐ๋ฒ•์„ ์‚ฌ์šฉํ•˜์—ฌ ์šฐ๋ฆฌ๋Š” ํ†ต๊ณผ ์™ธํ–‰์„ฑ์—์„œ์˜
09:19
a few transiting exoplanets that are undergoing atmospheric escape.
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๋Œ€๊ธฐ ํƒˆ์ถœ์„ ๋ช‡ ๋ฒˆ ๊ด€์ธกํ•  ์ˆ˜ ์žˆ์—ˆ์Šต๋‹ˆ๋‹ค.
09:24
And these planets can be called hot Jupiters,
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์šฐ๋ฆฌ๊ฐ€ ๋ฐœ๊ฒฌํ•œ ์ด๋Ÿฐ ์ข…๋ฅ˜์˜ ํ–‰์„ฑ์„
09:26
for some of the ones we've found.
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๋œจ๊ฑฐ์šด ๋ชฉ์„ฑ์ด๋ผ๊ณ  ํ•ฉ๋‹ˆ๋‹ค.
09:28
And that's because they're gas planets like Jupiter,
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๋ชฉ์„ฑ์ฒ˜๋Ÿผ ๊ธฐ์ฒด๋กœ ์ด๋ฃจ์–ด์ง„ ํ–‰์„ฑ์ด๊ณ 
09:31
but they're so close to their star,
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ํ•ญ์„ฑ์— ๋งค์šฐ ๊ฐ€๊น๊ธฐ ๋•Œ๋ฌธ์ด์ฃ .
09:32
about a hundred times closer than Jupiter.
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์‹ค์ œ ๋ชฉ์„ฑ๋ณด๋‹ค ๋ฐฑ ๋ฐฐ ์ •๋„์š”.
09:35
And because there's all this lightweight gas that's ready to escape,
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ํƒˆ์ถœํ•˜๊ธฐ ์‰ฌ์šด ๊ฐ€๋ฒผ์šด ๊ธฐ์ฒด๊ฐ€
09:38
and all this heating from the star,
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ํ•ญ์„ฑ์˜ ์—ด์„ ๋งŒ๋‚˜
09:40
you have completely catastrophic rates of atmospheric escape.
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๋ฌด์„œ์šด ์†๋„๋กœ ๋Œ€๊ธฐ ํƒˆ์ถœ์ด ์ผ์–ด๋‚ฉ๋‹ˆ๋‹ค.
09:44
So unlike our 400 pounds per minute of hydrogen being lost on Earth,
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์ง€๊ตฌ์˜ ๋ถ„๋‹น 400ํŒŒ์šด๋“œ(180kg)์™€๋Š”
09:48
for these planets,
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๋น„๊ต๋„ ์•ˆ ๋˜๋Š”
09:50
you're losing 1.3 billion pounds of hydrogen every minute.
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๋ถ„๋‹น 13์–ต ํŒŒ์šด๋“œ(59๋งŒ ํ†ค)์˜ ์ˆ˜์†Œ๊ฐ€ ํ–‰์„ฑ์„ ๋– ๋‚˜์ฃ .
09:55
So you might think, well, does this make the planet cease to exist?
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๊ทธ๋Ÿฌ๋‹ค ํ–‰์„ฑ ์ž์ฒด๊ฐ€ ๋‹ค ์†Œ์ง„๋ ๊นŒ ํ•˜๋Š” ์ƒ๊ฐ์„ ํ•  ์ˆ˜ ์žˆ๊ณ 
09:59
And this is a question that people wondered
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์ด๊ฒƒ์€ ํƒœ์–‘๊ณ„๋ฅผ ๋ฐ”๋ผ๋ณด๋ฉด์„œ
10:01
when they looked at our solar system,
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์‚ฌ๋žŒ๋“ค์ด ๊ถ๊ธˆํ•ดํ•œ ์งˆ๋ฌธ์ด์ฃ .
10:03
because planets closer to the Sun are rocky,
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ํƒœ์–‘์— ๊ฐ€๊นŒ์šด ํ–‰์„ฑ์€ ๋ฐ”์œ„๋กœ ์ด๋ฃจ์–ด์กŒ๊ณ 
10:05
and planets further away are bigger and more gaseous.
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๋ฉ€๋ฆฌ ์žˆ๋Š” ํ–‰์„ฑ์€ ๋” ํฌ๊ณ  ๊ธฐ์ฒด๋กœ ์ด๋ฃจ์–ด์ ธ ์žˆ์œผ๋‹ˆ๊นŒ์š”.
10:08
Could you have started with something like Jupiter
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์›๋ž˜๋Š” ๋ชฉ์„ฑ ๊ฐ™์€ ํ–‰์„ฑ์ด์—ˆ๋Š”๋ฐ
10:11
that was actually close to the Sun,
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ํƒœ์–‘ ๊ฐ€๊นŒ์ด ์žˆ๋‹ค ๋ณด๋‹ˆ
10:13
and get rid of all the gas in it?
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๊ธฐ์ฒด๊ฐ€ ๋‹ค ๋‚ ์•„๊ฐ„ ๊ฒƒ์ผ๊นŒ์š”?
10:14
We now think that if you start with something like a hot Jupiter,
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ํ˜„๋Œ€ ์ด๋ก ์— ๋”ฐ๋ฅด๋ฉด ๋œจ๊ฑฐ์šด ๋ชฉ์„ฑ์—์„œ
10:17
you actually can't end up with Mercury or the Earth.
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์ˆ˜์„ฑ์ด๋‚˜ ์ง€๊ตฌ ๊ฐ™์€ ๊ฒƒ์ด ๋งŒ๋“ค์–ด์งˆ ์ˆ˜๋Š” ์—†์Šต๋‹ˆ๋‹ค.
10:20
But if you started with something smaller,
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ํ•˜์ง€๋งŒ ๋” ์ž‘์€ ํฌ๊ธฐ๋กœ ์‹œ์ž‘ํ•˜๋ฉด
10:22
it's possible that enough gas would have gotten away
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ํ–‰์„ฑ์˜ ๋ชจ์Šต์„ ๋ฐ”๊ฟ€ ๋งŒํผ
10:25
that it would have significantly impacted it
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๋Œ€๋Ÿ‰์˜ ๋Œ€๊ธฐ ํƒˆ์ถœ์ด
10:27
and left you with something very different than what you started with.
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์ผ์–ด๋‚ฌ์„ ๊ฐ€๋Šฅ์„ฑ๋„ ์žˆ์Šต๋‹ˆ๋‹ค.
10:31
So all of this sounds sort of general,
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์ด ๋ชจ๋“  ๊ฒƒ์€ ์ผ๋ฐ˜๋ก ์ธ๋ฐ์š”.
10:33
and we might think about the solar system,
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ํƒœ์–‘๊ณ„๋กœ ์ขํ˜€ ์ƒ๊ฐํ•˜๋ฉด
10:35
but what does this have to do with us here on Earth?
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์ง€๊ตฌ์—๋Š” ๋ฌด์Šจ ์ผ์ด ์ผ์–ด๋‚ ๊นŒ์š”?
10:38
Well, in the far future,
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๋จผ ๋ฏธ๋ž˜์— ํƒœ์–‘์€ ๋” ๋ฐ์•„์งˆ ๊ฒƒ์ž…๋‹ˆ๋‹ค.
10:40
the Sun is going to get brighter.
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10:42
And as that happens,
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๊ทธ๋Ÿด์ˆ˜๋ก
10:43
the heating that we find from the Sun is going to become very intense.
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ํƒœ์–‘์˜ ์—ด๊ธฐ๋Š” ๋” ๊ฐ•๋ ฌํ•ด์ง€๊ณ 
10:47
In the same way that you see gas streaming off from a hot Jupiter,
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๋œจ๊ฑฐ์šด ๋ชฉ์„ฑ์—์„œ ๋ณด๋Š” ๊ฒƒ์ด
10:51
gas is going to stream off from the Earth.
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์ง€๊ตฌ์˜ ๊ธฐ์ฒด ํƒˆ์ถœ๋กœ ์ผ์–ด๋‚  ๊ฒƒ์ž…๋‹ˆ๋‹ค.
10:54
And so what we can look forward to,
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์šฐ๋ฆฌ๊ฐ€ ์˜ˆ์ƒํ•˜๊ณ 
10:56
or at least prepare for,
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์ค€๋น„ํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์€
10:58
is the fact that in the far future,
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๋จผ ๋ฏธ๋ž˜์— ์ง€๊ตฌ๋Š”
11:00
the Earth is going to look more like Mars.
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ํ™”์„ฑ์ฒ˜๋Ÿผ ๋ณด์ผ ๊ฒƒ์ด๋ผ๋Š” ์‚ฌ์‹ค์ž…๋‹ˆ๋‹ค.
11:03
Our hydrogen, from water that is broken down,
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๋ฌผ์—์„œ ๋ถ„๋ฆฌ๋œ ์ˆ˜์†Œ๊ฐ€
11:06
is going to escape into space more rapidly,
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๋น ๋ฅด๊ฒŒ ์šฐ์ฃผ๋กœ ํƒˆ์ถœํ•˜๊ณ 
11:08
and we're going to be left with this dry, reddish planet.
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์ง€๊ตฌ์—๋Š” ๋ถ‰๊ณ  ๋ฉ”๋งˆ๋ฅธ ํ‘œ๋ฉด์„ ๋‚จ๊ธฐ๊ฒ ์ฃ .
11:12
So don't fear, it's not for a few billion years,
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์•ž์œผ๋กœ ๋ช‡์‹ญ์–ต ๋…„ ๋™์•ˆ์€ ์ผ์–ด๋‚˜์ง€ ์•Š์„ ์ผ์ด๋‹ˆ
11:15
so there's some time to prepare.
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๋Œ€๋น„ํ•  ์‹œ๊ฐ„์€ ์ถฉ๋ถ„ํ•ฉ๋‹ˆ๋‹ค.
11:17
(Laughter)
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(์›ƒ์Œ)
11:18
But I wanted you to be aware of what's going on,
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ํ•˜์ง€๋งŒ ์ด๋ ‡๊ฒŒ ๋งํ•˜๋Š” ์ˆœ๊ฐ„์—๋„
11:21
not just in the future,
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๋Œ€๊ธฐ ํƒˆ์ถœ์ด
11:22
but atmospheric escape is happening as we speak.
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์กฐ๊ธˆ์”ฉ ์ผ์–ด๋‚˜๊ณ  ์žˆ๋‹ค๋Š” ๊ฒƒ์„ ์•Œ๊ณ  ๊ณ„์…จ์œผ๋ฉด ํ•ฉ๋‹ˆ๋‹ค.
11:25
So there's a lot of amazing science that you hear about happening in space
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๋ฉ€๋ฆฌ ๋–จ์–ด์ง„ ์šฐ์ฃผ์˜ ํ–‰์„ฑ์—์„œ๋Š”
11:29
and planets that are far away,
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๋‹ค์–‘ํ•œ ํฅ๋ฏธ๋กœ์šด ์ผ์ด ์ผ์–ด๋‚˜๊ณ 
11:31
and we are studying these planets to learn about these worlds.
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์šฐ๋ฆฌ๋Š” ์ด ์™ธ๋ถ€ ์„ธ๊ณ„๋ฅผ ํƒ๊ตฌํ•˜๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค.
11:34
But as we learn about Mars or exoplanets like hot Jupiters,
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ํ•˜์ง€๋งŒ ํ™”์„ฑ์ด๋‚˜ ๋œจ๊ฑฐ์šด ๋ชฉ์„ฑ ๊ฐ™์€ ์™ธ๊ณ„ํ–‰์„ฑ์„
11:38
we find things like atmospheric escape
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ํƒ๊ตฌํ•˜๋‹ค ๋ณด๋ฉด ๋Œ€๊ธฐ ํƒˆ์ถœ ๊ฐ™์ด
11:42
that tell us a lot more about our planet here on Earth.
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์ง€๊ตฌ์— ๋Œ€ํ•ด์„œ๋„ ๋ฐฐ์šธ ์ˆ˜ ์žˆ๊ฒŒ ๋ฉ๋‹ˆ๋‹ค.
11:45
So consider that the next time you think that space is far away.
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๊ทธ๋Ÿฌ๋‹ˆ ์šฐ์ฃผ๊ฐ€ ๋จผ ๋‚˜๋ผ ์–˜๊ธฐ๋ผ๊ณ ๋งŒ์€ ์ƒ๊ฐํ•˜์ง€ ๋ง์•„ ์ฃผ์„ธ์š”.
11:49
Thank you.
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๊ฐ์‚ฌํ•ฉ๋‹ˆ๋‹ค.
11:51
(Applause)
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(๋ฐ•์ˆ˜)
์ด ์›น์‚ฌ์ดํŠธ ์ •๋ณด

์ด ์‚ฌ์ดํŠธ๋Š” ์˜์–ด ํ•™์Šต์— ์œ ์šฉํ•œ YouTube ๋™์˜์ƒ์„ ์†Œ๊ฐœํ•ฉ๋‹ˆ๋‹ค. ์ „ ์„ธ๊ณ„ ์ตœ๊ณ ์˜ ์„ ์ƒ๋‹˜๋“ค์ด ๊ฐ€๋ฅด์น˜๋Š” ์˜์–ด ์ˆ˜์—…์„ ๋ณด๊ฒŒ ๋  ๊ฒƒ์ž…๋‹ˆ๋‹ค. ๊ฐ ๋™์˜์ƒ ํŽ˜์ด์ง€์— ํ‘œ์‹œ๋˜๋Š” ์˜์–ด ์ž๋ง‰์„ ๋”๋ธ” ํด๋ฆญํ•˜๋ฉด ๊ทธ๊ณณ์—์„œ ๋™์˜์ƒ์ด ์žฌ์ƒ๋ฉ๋‹ˆ๋‹ค. ๋น„๋””์˜ค ์žฌ์ƒ์— ๋งž์ถฐ ์ž๋ง‰์ด ์Šคํฌ๋กค๋ฉ๋‹ˆ๋‹ค. ์˜๊ฒฌ์ด๋‚˜ ์š”์ฒญ์ด ์žˆ๋Š” ๊ฒฝ์šฐ ์ด ๋ฌธ์˜ ์–‘์‹์„ ์‚ฌ์šฉํ•˜์—ฌ ๋ฌธ์˜ํ•˜์‹ญ์‹œ์˜ค.

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