Aomawa Shields: How we'll find life on other planets | TED

Translator: Ellen Zhang Reviewer: Alan Watson

I am in search of another planet in the universe where life exists.

我喺度搵緊其他有生命存在嘅星球

I can't see this planet with my naked eyes

雖然我唔能夠用肉眼睇到呢啲星球

or even with the most powerful telescopes

就算用埋最先進嘅望遠鏡

we currently possess.

But I know that it's there.

但我知道佢就喺嗰度

And understanding contradictions that occur in nature

而且掌握大自然本身嘅矛盾

可以幫到我哋搵到呢個星球

will help us find it.

On our planet,

響我哋嘅星球

where there's water, there's life.

邊度有水，邊度就有生命

So we look for planets that orbit at just the right distance

所以我哋尋找嗰啲

同恒星保持合適運行距離嘅星球

from their stars.

At this distance,

呢個表入面

shown in blue on this diagram for stars of different temperatures,

藍色係代表咗唔同恒星嘅適居帶

planets could be warm enough for water to flow on their surfaces

而呢種距離暖到 可以令水喺星球嘅表面流動

as lakes and oceans

形成咗湖同海

where life might reside.

而生命就有可能響呢啲地方出現

Some astronomers focus their time and energy on finding planets

一啲天文學家集中精神

尋找位於適居帶嘅星球

at these distances from their stars.

What I do picks up where their job ends.

我嘅任務就係接手佢哋嘅工作

I model the possible climates of exoplanets.

我要推算出系外行星嘅氣候

And here's why that's important:

下面我會講解點解呢樣會咁重要

there are many factors besides distance from its star

除咗距離之外

that control whether a planet can support life.

仲有好多其他因素 決定一個星球有生命嘅存在

Take the planet Venus.

就攞金星做例子

It's named after the Roman goddess of love and beauty,

佢嘅名代表咗羅馬人 一個象徵愛同美麗嘅女神

because of its benign, ethereal appearance in the sky.

正因為佢喺天空 以美善、輕飄嘅姿態出現

But spacecraft measurements revealed a different story.

但探測器做出嘅測量欲唔係想像中咁靚

The surface temperature is close to 900 degrees Fahrenheit,

金星表面嘅溫度高達華氏 900度

亦即攝氏500度

500 Celsius.

That's hot enough to melt lead.

佢嘅溫度足夠融咗鉛

Its thick atmosphere, not its distance from the sun, is the reason.

佢厚厚嘅大氣層 而唔係佢同太陽嘅距離

令大氣層出現溫室效應

It causes a greenhouse effect on steroids,

太陽嘅熱力被大氣層鎖住

trapping heat from the sun and scorching the planet's surface.

熱力留返喺度，將星球表面加熱

The reality totally contradicted initial perceptions of this planet.

現實同我哋最初對金星嘅想像係倒返轉

From these lessons from our own solar system,

從太陽系學到，一個星球嘅大氣

we've learned that a planet's atmosphere

is crucial to its climate and potential to host life.

對星球嘅氣候以至生命嘅孕育 係非常之重要

We don't know what the atmospheres of these planets are like

我哋唔知道呢啲系外行星嘅大氣係點樣

because the planets are so small and dim compared to their stars

因為呢啲星球相比起佢哋嘅恒星

and so far away from us.

實在太細啦，兼且離我哋太遠啦

For example, one of the closest planets that could support surface water --

例如，其中一個

最接近我哋又可以維持地表水嘅星球

it's called Gliese 667 Cc --

叫做 Gliese 667 Cc

such a glamorous name, right, nice phone number for a name --

真係一個有魅力嘅名

好似個電話號碼咁

it's 23 light years away.

佢距離我哋有 23 光年咁遠

So that's more than 100 trillion miles.

超過一兆英里

Trying to measure the atmospheric composition

要響系外行星經過佢哋恒星嗰時 量度佢哋嘅大氣組成

of an exoplanet passing in front of its host star is hard.

係非常艱難嘅

It's like trying to see a fruit fly

就好似嘗試望住隻果蠅 飛過一架車嘅前燈

passing in front of a car's headlight.

OK, now imagine that car is 100 trillion miles away,

好，你可以想像嗰架車離你一兆英里

and you want to know the precise color of that fly.

而你只想知嗰隻果蠅嘅顏色

So I use computer models

所以我利用一個電腦模擬程式

to calculate the kind of atmosphere a planet would need

去計算星球需要乜嘢大氣層

to have a suitable climate for water and life.

先至會有合適嘅氣候提供水同孕育生命

Here's an artist's concept of the planet Kepler-62f,

呢度係畫家對開普勒-62f 概念嘅理解

with the Earth for reference.

用地球做參照

It's 1,200 light years away,

佢有 1,200 光年咁遠

and just 40 percent larger than Earth.

比地球大 40%

Our NSF-funded work found that it could be warm enough for open water

我哋 NSF 資助嘅項目發現

無論佢嘅大氣同運行軌道嘅方向係咩

from many types of atmospheres and orientations of its orbit.

佢都夠暖俾到水出現

So I'd like future telescopes to follow up on this planet

所以，我想未來嘅望遠鏡 可以追蹤呢個星球

to look for signs of life.

去搵出星球上面嘅生命線索

Ice on a planet's surface is also important for climate.

星球表面嘅冰 係另一種決定氣候嘅重要因素

Ice absorbs longer, redder wavelengths of light,

冰吸收長波，偏紅嘅光

反射短波嘅藍光

and reflects shorter, bluer light.

That's why the iceberg in this photo looks so blue.

呢個就係點解呢幅圖嘅冰咁藍

The redder light from the sun is absorbed on its way through the ice.

嚟自太陽嘅紅光通過冰塊時就被吸收

Only the blue light makes it all the way to the bottom.

剩低藍光穿過底部出返嚟

Then it gets reflected back to up to our eyes

之後藍光反射到我哋嘅眼

and we see blue ice.

所以我哋見到藍色嘅冰

My models show that planets orbiting cooler stars

我嘅模型推算出 星球圍繞溫度較低嘅恒星時

could actually be warmer than planets orbiting hotter stars.

佢嘅溫度 會比圍繞較熱嘅恒星嘅星球更高

There's another contradiction --

下面係第二個矛盾︰

that ice absorbs the longer wavelength light from cooler stars,

冰吸收嚟自溫度較低嘅恒星 波長較長嘅光

光，或者能量，令冰嘅溫度上升

and that light, that energy, heats the ice.

Using climate models to explore

探索呢啲矛盾嘅嘢點樣影響星球氣候

how these contradictions can affect planetary climate

is vital to the search for life elsewhere.

對於尋找外星生命 係非常重要嘅

And it's no surprise that this is my specialty.

絕對唔係意外，呢個係我鑽研方向

I'm an African-American female astronomer

我係非裔女性美國天文學家

and a classically trained actor

亦係一個受過真正訓練嘅演員

who loves to wear makeup and read fashion magazines,

鍾意化妝，睇時尚雜誌

so I am uniquely positioned to appreciate contradictions in nature --

所以我好欣賞大自然存在嘅矛盾

(Laughter)

（笑聲）

(Applause)

（掌聲）

呢啲矛盾引領我哋研究

... and how they can inform our search for the next planet where life exists.

將我哋帶到下一個有生命存在嘅星球

My organization, Rising Stargirls,

我嘅組織， Rising Stargirls

teaches astronomy to middle-school girls of color,

通過戲劇表演、寫作同視覺藝術

using theater, writing and visual art.

教授天文學俾唔同膚色嘅中學女生

That's another contradiction -- science and art don't often go together,

呢個又係另一個矛盾

科學同藝術好多時唔能夠喺埋一齊

but interweaving them can help these girls bring their whole selves

但係將佢哋擺埋一齊

可以令佢哋明白佢哋學嘅嘢

to what they learn,

and maybe one day join the ranks of astronomers

或者有一日 佢哋會加入天文學家嘅行列

who are full of contradictions,

呢個充滿矛盾發現嘅職業

and use their backgrounds to discover, once and for all,

利用佢哋嘅背景

探索到我哋唔係宇宙中唯一嘅生物

that we are truly not alone in the universe.

Thank you.

多謝

(Applause)

（掌聲）