冰層下的外星人——流浪行星上的生命：英語精讀講義

Rogue planets are planets that travel through the universe alone.

流浪行星是在宇宙中獨自穿行的行星。

They inhabit the dark and vast space between the stars.

它們棲身於恆星之間黑暗而廣闊的空間。

Drifting alone through eternal darkness,

在無盡的黑暗中獨自漂泊，

no light warms their surfaces

沒有光能溫暖它們的表面，

and they're exposed to the freezing cold of outer space.

且它們暴露在外太空極度的嚴寒之中。

They know no seasons,

它們沒有四季，

no days, and no nights

也沒有晝夜

which could give away the passing of time. 片語動詞

能用來揭示時間的流逝。

And yet, 表達脈絡

然而，

rogue planets might carry alien life to all corners of the galaxy.

流浪行星可能會將外星生命帶到銀河系的各個角落。

How would that work?

這是怎麼做到的？

And how does a planet become a rogue anyway?

又或者，行星到底是如何變成流浪行星的？

There are several very different things

有幾種截然不同的天體

that get called rogue planets.

都被稱為流浪行星。

For example,

例如，

sub-brown dwarfs,

次棕矮星、

gas giants

氣體巨行星，

that form from collapsing gas clouds

由坍縮的氣體雲形成的

and are the boring little brothers of brown dwarfs.

它們是棕矮星無趣的小兄弟。

They're a sort of failed star 片語搭配

它們算是某種失敗的恆星，

and we'll now stop talking about them.

現在我們不再談論它們了。

A far more interesting sort of rogue

更讓人感興趣的一類流浪者，

are terrestrial planets

是類地行星，

similar to Earth

也就是與地球相似

that got kicked out of their planetary system. 片語動詞

但被踢出其行星系統的行星。

Young star systems are dangerous places

年輕的星系是危險的地方，

where protoplanets are battling for the available mass,

原行星在那裡爭奪可用的質量，

guzzling up as much material as possible. 用詞

貪婪地吞噬著盡可能多的物質。

In this fight for dominance,

在這場爭奪主導權的戰鬥中，

they collide with each other

它們會相互碰撞，

or get dangerously close to each other's orbits.

或者危險地靠近彼此的軌道。

If a very massive planet

如果一顆質量很大的行星

moves its orbit closer to the star,

將軌道移向恆星，

it can kick smaller planets

它就能把較小的行星

out of the system.

踢出該系統。

But just because a planet has survived the growing pains of formation, 文法

但是，就算一顆行星熬過了形成期的陣痛，

doesn't mean it's safe.

也並不意味著它就安全了。

Planetary systems can be disrupted by flybys from stars or black holes at any point. 用詞

行星系統隨時都可能被飛掠而過的恆星或黑洞擾亂。

Up to half of all planets born

所有誕生的行星中，多達一半

could end up as rogues. 片語動詞

可能最終會淪為流浪者。

Scientists don't agree on the numbers,

科學家們在具體數字上存在分歧，

but it's likely that at the very least, 片語搭配

但很可能，至少，

there are billions of rogue planets

有數十億顆流浪行星

in the Milky Way alone.

單單存在於銀河系中。

Most rogues will share the same depressing fate.

大多數流浪行星都會面臨同樣令人沮喪的命運。

As their star becomes smaller day by day,

隨著它們的恆星一天天變得渺小，

the planet's surface quickly cools down to minus 270 degrees Celsius.

行星表面的溫度會迅速下降到零下270攝氏度。

If they have oceans,

如果它們有海洋，

they'll freeze and become as hard as bedrock.

海洋就會凍結，變得像基岩一樣堅硬。

Their atmospheres will sink down to the surface

它們的大氣層會沉降到表面，

and eventually freeze too.

並最終也會凍結。

But weirdly enough, 片語搭配

但不可思議的是，

some of these frozen dark deserts

這些冰凍黑暗的荒漠中，有些

could harbor life. 用詞

卻可能孕育生命。

To understand how,

為了理解其中的原因，

let's imagine a planet similar to Earth

讓我們想像一顆類似地球的行星，

in the same order of magnitude 用詞

在同一個數量級上，

in terms of mass and composition. 片語搭配

無論是在質量還是成分方面。

If we put it into deep space,

如果把它放入深空，

how could it still support life?

它怎麼還能維持生命呢？

As far as we understand the nature of life, 表達脈絡

就我們對生命本質的理解而言，

there is one indispensable ingredient it needs,

生命需要一種不可或缺的成分：

liquid water.

液態水。

Water is important because it mixes things,

水之所以重要，是因為它能混合事物，

both matter and energy,

包括物質和能量，

which lets interesting chemistry happen, 文法

從而發生有趣的化學反應，

like life.

比如生命。

So our planet needs enough energy

所以，我們的這顆行星需要足夠的能量，

to keep at least a part of our oceans warm

來保持至少一部分海洋足夠溫暖

enough to sustain liquid water. 文法

以維持液態水。

Annoyingly, about 99.97% of Earth's energy

讓人頭疼的是，地球大約99.97%的能量

budget comes from the sun.

收支來自太陽。

So our imaginary rogue Earth

所以我們假想的流浪地球

needs to work with the 0.03% of energy it has left, 片語動詞

必須利用它僅存的0.03%的能量運作，

which almost exclusively

這些能量幾乎完全

comes from its hot center.

來自它滾燙的中心。

Earth's inner core is a giant metal ball

地球的內核是一個巨大的金屬球，

about as hot as the surface of the sun

溫度幾乎和太陽表面一樣高，

that's surrounded by the outer core

它被外核包裹著，

made up of liquid metals 片語動詞

外核由液態金屬組成，

that are very, very slowly solidifying,

這些金屬正非常、非常緩慢地凝固，

releasing a lot of heat in the process. 片語搭配

在此過程中會釋放大量熱量。

As long as this process is ongoing, 文法

只要這個過程還在繼續，

our planet will be geologically active,

我們的行星就會保持地質活躍，

with solid and liquid material

固態和液態物質

moving around

會四處流動，

and transporting energy to the surface

並將能量輸送到表面，

where it can be harnessed

在那裡它可以被利用

as geothermal energy.

作為地熱能。

While the hot core of every planet

雖然每顆行星炙熱的核心

will cool off eventually,

最終都會冷卻，

this process takes billions of years,

但這過程需要數十億年，

enough time

有足夠的時間

for life to come into existence and thrive. 片語搭配

讓生命誕生和繁衍。

There's even one scenario that could allow an Earth-like planet

甚至有一種情況能讓類地行星

to have oceans

擁有海洋

that are not frozen over. 片語動詞

且不會被完全凍結。

If the planet had an extremely dense and high pressure hydrogen atmosphere,

如果這顆行星擁有密度極大、壓力極高的氫氣大氣層，

the gas would not freeze and could trap enough of the heat trying to escape the planet

這種氣體不會凍結，並且能困住試圖逃逸出星體的足夠熱量，

to enable oceans

從而讓海洋

that extend all the way to the surface. 片語搭配

一直延伸到表面。

And there's another possible way to stay warm, 表達脈絡

還有另一種可能保暖的方法：

moons.

衛星。

If a rogue planet

如果一顆流浪行星

brings a moon or more along with them,

攜帶著一顆或多顆衛星，

a large enough moon

那麼足夠大的衛星

could inject additional energy

就可以注入額外的能量

into the system via tidal forces. 用詞

通過潮汐力進入該系統。

These forces

這些力量

stretch and squeeze the planet

會拉伸和擠壓行星，

a little bit every day,

每天稍微來一點，

like kneading dough, 表達脈絡

就像揉麵團一樣，

keeping it warm.

讓它保持溫暖。

But the most likely scenario

但對於一顆孕育生命的流浪行星而言，

for a rogue bearing life 用詞

最有可能的情況

is one with subglacial oceans

是擁有冰下海洋，

under a kilometer thick layer

隱藏在厚達一公里的

of mostly water ice.

主要由水冰構成的冰層之下。

These are not completely absurd, 表達脈絡

這並非完全荒唐，

since we already have a few of them in the solar system.

因為在太陽系中我們就已經有幾個這樣的例子了。

So how could life

那麼生命如何能夠

sustain itself at the bottom

在深處維持自身呢？

of a completely dark,

在完全黑暗、

cold ocean?

冰冷的海洋底部？

On Earth,

在地球上，

deep down in our oceans

在我們海洋深處

in complete darkness,

完全黑暗的地方，

in volcanically active areas,

在火山活動活躍的區域，

there are hydrothermal vents called black smokers. 用詞

有一種叫做黑煙囪的熱液噴口。

They spew out a cloud 片語動詞

它們噴出一團團

of black material and hot water,

黑色物質和熱水，

providing a constant flow

提供了持續不斷的

of minerals from Earth's mantle.

來自地函的礦物水流。

Bacteria feed on the minerals 片語動詞

細菌以這些礦物質為食，

and produce organic materials,

並產生有機物質，

which attracts crustaceans,

這吸引了甲殼類、

bivalves,

雙殼類、

snails,

蝸牛、

fish, octopus, and tube worms

魚類、章魚以及管蠕蟲，

up to 2 m long.

長度可達2公尺。

Not only are hydrothermal vents 文法

熱液噴口不僅是

home to an incredibly diverse 片語搭配

種類極其多樣的

group of living beings,

生物群落的家園，

but also a contender

而且還是一個有力的競爭者，

for the place where life

可能就是生命

could have begun on Earth

在地球上開始的地方

billions of years ago.

在數十億年前。

In the dark ocean

在幽暗的海洋中，

of a rogue planet,

屬於一顆流浪行星，

similar vents

類似的噴口

or volcanic activity could be the starting point

或火山活動可能是起點，

and basis for complex ecosystems

並且是複雜生態系統的基礎，

we can only imagine right now.

我們現在只能去想像它。

One upside an ecosystem

一個流浪行星海洋中

in a rogue planet ocean

生態系統的一大優勢

has is that the environment

是這裡的環境

is extremely stable.

極其穩定。

The thick ice sheet protects it from all sorts

厚厚的冰層保護它免受各種

of extinction events,

滅絕事件的影響，

and as long as the energy

只要能量

from the core keeps on coming,

持續不斷地從核心湧出，

things stay pretty much the same.

情況就幾乎不會改變。

The most likely forms

最有可能的生命形式

of life are bacteria

是細菌

and other microorganisms,

和其他微生物，

but given enough time, 文法

但只要有足夠的時間，

more complex alien animals

更複雜的外星動物

could feed on the smaller beings

可能會以更小的生物為食

and thrive.

並繁榮發展。

It's not impossible that intelligent 文法

在這種環境下出現智慧生命

life could emerge in such an environment.

也不是不可能的。

If it did,

如果真的出現了，

it would find itself

它會發現自己

in a pretty weird world.

置身於一個非常怪異的世界裡。

Constricted by an impassable

被上方不可逾越的

wall of rock hard ice at the top

堅如岩石的冰牆

and bedrock at the bottom.

和下方的基岩所限制。

Without any plants

沒有植物

to store star energy,

來儲存恆星的能量，

there would be no wood, oil, or coal.

就不會有木材、石油或煤炭。

Even if there were,

即便有，

it's not like you'd discover fire 語氣意圖

你也不可能在海洋底部

at the bottom of an ocean.

發現火。

Without this energy,

沒有這種能量，

metals may never be forged

金屬可能永遠無法被鍛造

into useful things.

成有用的工具。

Our intelligent alien

我們聰明的外星

friends might never break through the ice. 片語動詞

朋友可能永遠無法破冰而出。

They might never realize

他們可能永遠不會意識到

that there is such a thing as outside 片語搭配

有外面這回事，

and assume that their small world

並假設他們微小的世界

is all there is. 文法

就是宇宙的全部。

Millions of generations

數以百萬計的世代

might live and die in these dark oceans,

可能在這些黑暗的海洋中生與死，

ignorant of the unbelievably big universe 用詞

對大得不可思議的宇宙一無所知

above the ice,

在那冰層之上，

until the core of their planet

直到他們行星的內核

cools off and all life vanishes.

徹底冷卻，所有生命消失殆盡。

As the oceans completely freeze,

隨著海洋完全凍結，

the remnants

文化和生態系統的

of cultures and ecosystems

遺跡

will be trapped

將被永遠困在

in an icy grave forever. 慣用語

一個冰冷的墳墓裡。

If you think about it, 表達脈絡

想想看，

it might be better

也許不知道這些

not to be aware of all that.

反而更好。

But the concept is disturbing

但這概念讓人不安，

and exciting.

又令人興奮。

The universe

宇宙

might be teeming with life 片語搭配

可能到處都是生命，

trapped on planets

被困在行星上，

that are basically impossible

基本上不可能

to leave. Worlds

離開。諸如此類的世界

like this could frequently pass

可能會頻繁掠過

the solar system

太陽系，

without us even knowing. 文法

而我們甚至一無所知。

Maybe one day,

也許有一天，

in the far future,

在遙遠的未來，

humans

人類

will set foot on one 慣用語

將涉足這些冰凍世界中的

of these frozen worlds

一個，

and try to say hello.

試著去說聲你好。