They come in all sizes,

它們有各種大小

at different orbital distances from their stars.

和他們的星球有不同的繞行距離

The closest of them are trillions of miles away,

最近的大約是幾兆哩這麼遠

and even the largest are just fuzzy patches

即便是最大的行星也大概只有補丁大小

in the fields of high-powered telescopes.

在高性能望遠鏡中看起來

But if one of these planets is close in size to the Earth

但是如果其中一個行星和地球差不多大

and orbits not too close and too far away from its parent star,

而它的母星和它保持著適當的距離

it could be rocky and warm enough to have oceans

就會有足夠的岩石和溫度來製造海洋

and perhaps life.

也許還會有生命

Astronomers discover these potentially habitable planets,

天文學家發現這些可能可以居住的星球

and their eyes get big and wide.

讓他們大開眼界

Could one of these distant worlds carry the building blocks of life?

這其中一個遙遠的世界是否可以孕育生命呢？

Or even a living, breathing, civilization?

甚至是一個活生生的文明人？

Is the question, "Are we alone in the universe?" about to be answered?

「我們是宇宙中唯一有生命的地方嗎？」這個問題是否可以找到解答？

But wait.

但是，等等

Maybe we should ask a different question first.

也許我們先該問另一個問題

Should we try to find out if we're alone in the universe?

我們應該要找出我們是否是宇宙中唯一有生命的星球嗎？

If we do find the atmospheric fingerprints of life

如果我們真的找到了有大氣層保護的生命

on one of these small, distant worlds,

在其中一個又小又遠的世界

should we try to contact any beings who may live there?

我們應該試著聯絡住在上面的生物嗎？

Is that wise?

這是明智的決定嗎？

Three decades ago, NASA decided the answer was yes.

三十年前，美國國家航空暨太空總署認為這個答案是「是」

Voyager 1 and 2 were launched in 1977

1977年發射了探險者一號和二號

to explore the giant planets in the solar system.

來探索太陽系的大型行星

Each spacecraft carried a golden phonograph record,

每一個太空船配有一個金製的留聲機

a time capsule of sorts that included clues and messages

一個時光膠囊包含線索與訊息

meant to convey the story of human civilization.

來訴說人類文明的故事

The contents of these gold-plated copper disks were chosen by a committee

這些鍍金的銅製磁碟是由一個委員會選出

chaired by American astronomer and author Carl Sagan.

委員會的會長由同時為美國天文學家與作家的Carl Sagan擔任

They included over 100 images,

這些磁碟包含超過100張的影像

and a range of sounds from the natural world:

還有大自然的聲音

ocean waves,

像是海浪

thunder,

雷聲

the sounds of birds

鳥鳴

and whales.

和鯨魚

The records also included music from many different time periods and cultures,

這些錄音包含許多不同時期、不同文化的音樂

greetings in 55 languages,

並且有五十五種語言的翻譯

and messages from the President of the United States,

還有美國總統的留言

and the UN Secretary General.

以及聯合國秘書長的留言

They also included a map.

這些磁碟片還包含一個地圖

Each golden record displays the location of our solar system

每個金製磁碟片可顯示太陽系的位置

with respect to fourteen pulsars.

和十四個脈衝星

Their precise, unique frequencies were indicated

顯示出它們精確、獨特的頻率

so that intelligent, extraterrestrial lifeforms

因此地球外聰明的生物

could use them to find the Earth.

可以透過這些磁碟找到地球

Many years later, renowned physicist Stephen Hawking said

多年以後，有名的物理學家Stephen Hawking說

that it was a mistake to give an alien species a roadmap to our planet.

給一個外星生物來到我們星球的地圖是個錯誤的行為

Hawking suspected that any extraterrestrial life

Hawking質疑地球外的生物

probably wasn't any more complex than microbes,

很有可能頂多和微生物差不多

but he warned that if an advanced alien species did visit Earth,

但是他也提出警告，如果任何一個優越的外星物種真的拜訪地球

it could be as catastrophic as Christopher Columbus's arrival was

可以會變成一個大災難，像是哥倫布抵達

for the Native Americans.

美國一樣

Meanwhile, the golden records continue their journeys.

與此同時，金製磁碟仍然繼續它們的旅程

In 1990, both Voyager spacecraft passed beyond the orbit of Pluto.

1990年，探險者太空船經過冥王星的衛星

Voyager 1 entered interstellar space in 2012,

2012年，探險者一號進入星際空間

and will reach the nearest stellar system in 40,000 years.

將會在四萬年內進入最近的行星系統

If either spacecraft is discovered by extraterrestrial life,

如果其中一艘太空船被地球外的生物發現

there's a possibility that they could decipher the clues from the golden record

他們就有可能從金製磁碟中找到線索

and one day reach our planet.

有一天來到我們的星球

That's particularly true

這是真的

if theirs is a much more technologically advanced civilization.

如果他們是一個更加高科技、高度文明的星球

That life could be benevolent,

住在那裡的生物是和平、和善的

as we would hope to be if humans are one day able to achieve interstellar travel.

那我們就可以期待人類有一天真的能夠在星際間旅行

Or it could be hostile.

如果他們是充滿敵意的

Searching for planets that might have life means staring into a great abyss.

找尋有生物存在的星球，可能會讓我們踏進無底深淵中

We'll likely have no clear knowledge of the evolutionary stage,

在發展階段，我們可能還沒有清楚、足夠的知識來理解

sentience,

知覺

character,

特徵

or intentions of the first form of life we discover.

或是我們發現的第一種生物的意圖

So it's a risk to turn our eyes outwards.

所以向外尋找生命具有風險

We risk our very way of life.

我們正在冒險

But it may be a greater risk not to look,

但是更大的風險可能是我們不去看

to deny the very pioneering spirits that help shape our own species.

並且否定塑造我們自己物種的開拓精神

We are all born curious about the world and the universe.

我們生來就對這個世界和宇宙充滿好奇

Pursuing that curiosity is one of humankind's greatest achievements.

充滿好奇心是人類最棒的成就之一

Perhaps there is room to push the frontiers of science,

也許科學的邊界還有辦法再繼續往外延伸

provided that we cradle alongside our fervor

因為我們的熱情未曾間斷

Another of humankind's greatest assets:

也就是人類另一個最棒的資產

hope.

希望