The most devastating asteroid to hit Earth - Sean P. S. Gulick

譯者: Lilian Chiu 審譯者: Wei C.

66 million years ago, near what’s now the Yucatán Peninsula,

六千六百萬年前

在現在的猶加敦半島附近

a juvenile sauropod feasted on horsetail plants on a riverbank.

一隻年幼的蜥腳類恐龍 在河岸上吃馬尾草

Earth was a tropical planet.

那時的地球是熱帶行星

Behemoth and tiny dinosaurs alike roamed its lands,

巨獸和小型的恐龍 都在地球的陸地上漫遊

while reptiles and tentacled ammonites swept its seas.

爬蟲類和拖著觸鬚的菊石 在海洋中遨遊

But, in an instant, everything would change.

但是，馬上就會風雲變色

A roughly 12-kilometer-wide asteroid was careening toward Earth

一個直徑約十二公里的小行星 正在快速接近地球

at around 20 kilometers per second.

速度約為每秒二十公里

From where the sauropod stood,

從蜥腳類恐龍站的地方來看 沒有任何提早警示的徵兆

there would have been no early warning signs.

The asteroid barreled through Earth's atmosphere in a matter of seconds

小行星在幾秒鐘內 穿過地球的大氣層

and struck the Yucatán’s submerged continental shelf.

撞擊到尤卡坦半島水下的大陸棚

It exploded upon impact,

它在撞擊當下立刻爆炸

instantaneously creating a 100-kilometer-wide hole

馬上造成一個直徑一百公里的坑洞

and ejecting sedimentary and crystalline rocks.

噴出沉積岩和結晶岩石

Within minutes, the impact crater, known today as Chicxulub,

幾分鐘內，撞擊的坑洞

即現今稱為希克蘇魯伯隕石坑

began collapsing inwards.

開始向內崩垮

Meanwhile, the base rebounded some 20 kilometers above the Earth’s surface,

同時，基部反彈到 地球表面上二十公里高

then fell back down and moved outwards, creating a ring of mountains.

接著又落下，並向外移動

創造出環繞的山脈

The energy released from the asteroid’s impact is estimated to have been

小行星撞擊所釋放的能量

據估計是核彈的數十億倍

several billion times that of a nuclear bomb.

The force sent seismic energy across the planet

這股力將地震能量送至地球各處

at a much greater magnitude than any earthquake

強度遠大於任何地質斷層 所能產生的地震

a tectonic fault could ever produce.

Massive landslides ensued.

隨後發生了大規模的山崩

And a tsunami sped from the newly formed crater,

一場海嘯從新形成的坑洞 迅速向外迅速推進

potentially reaching 1,500 meters high.

高度可能高達一千五百公尺

Countless lives were extinguished.

無數生命就這麼消失了

Some instantly: all life within 1,500 kilometers of the impact site

有些是在一瞬間

撞擊點方圓一千五百公里內的 所有生命都被焚化了

was incinerated;

others right after: by colossal waves, landslides, and hurricane force winds.

接著就是其他生命

死於巨浪、山崩和颶風級的強風

But many organisms across the planet survived.

但地球各地有許多生物存活下來

It was what came next that would bring about the end for many species,

接下來發生的事造成了 許多物種的滅絕

including almost all dinosaurs.

包括幾乎所有的恐龍

This was just the beginning of one of the most devastating periods

地球生命史中最毀滅性的時期之一

in the history of life on Earth.

才剛剛開始

When the asteroid struck, it sent hundreds of gigatons

小行星撞擊時

將數千億噸富含二氧化碳的石灰岩

of carbon-dioxide-rich limestone and sulfur-saturated-sediments

以及富含硫的沉積物送入大氣中

into the atmosphere.

The sulfur combined with water vapor to create sulfate aerosols.

硫與水蒸氣結合

形成硫酸鹽氣溶膠

This plume of limestone dust, soot, and sulfate aerosols

這股由石灰岩塵埃、煤煙 和硫酸鹽氣溶膠組成的煙雲

spread from the impact site at several kilometers per second,

以每秒數公里的速度 從撞擊點快速散播開來

blanketing the globe in a matter of hours.

在幾小時內就覆蓋了全球

It’s thought to have blocked the Sun,

一般認為是煙雲阻擋了陽光

plunging Earth into an extended period of darkness

使地球陷入漫長的黑暗時期

and dropping the temperature in many places by at least 25°C.

並讓許多地方的溫度下降了 至少攝氏二十五度

The asteroid’s immediate impact was devastating,

小行星撞擊的影響是毀滅性的

but it seems to have been the rapid climate change it triggered

但似乎是它所觸發的快速氣候變遷

that ended the roughly 165-million-year reign of the dinosaurs.

終結了恐龍在地球上約 一億六千五百萬年的統治

Plants and plankton rapidly died,

植物和浮游生物迅速死亡

causing the collapse of food webs worldwide.

導致全球食物網絡崩壞

An estimated 75% of life on Earth went extinct,

估計地球上的生命 有 75％ 都因此絕種

including almost all dinosaurs.

包括幾乎所有的恐龍

Small birds were the only kinds that remained,

唯一留存下來的是小型鳥

perhaps because they relied on hardy seeds that weathered the catastrophe.

也許是因為牠們賴以維生的耐久種子

能撐得過這場災難

It's unclear why exactly the lifeforms that survived the extinction did.

目前尚不清楚存活下來的生物 究竟是為什麼存活下來

Many smaller organisms, like insects, persisted.

許多較小的生物 如昆蟲，仍然存在

So did early mammals— perhaps because of their ability to burrow and hibernate.

還有早期的哺乳類動物

也許是因為牠們有 挖地洞躲藏和冬眠的能力

And photosynthetic lifeforms like algae,

靠光合作用的生物，例如藻類

that had ways of withstanding low-light conditions,

有辦法承受光線不足的條件

also survived.

因此也活了下來

Traces of the asteroid scattered worldwide and the scar of the Chicxulub crater

小行星的碎片遍佈世界各地

而希克蘇魯伯隕石坑的疤痕

attest to this period of monumental destruction.

是這個毀滅性時代的證明

So, what are the chances of another Chicxulub happening?

那麼，再發生一次希克蘇魯伯 事件的機會有多大？

Space programs are continuously identifying and tracking

太空計畫持續不斷在辨識和追蹤

near-Earth asteroids.

靠近地球的小行星

Fortunately, the likelihood of one as large and cataclysmic

幸運的是，在接下來一千年 左右有這麼巨大的小行星

striking in the next thousand or so years seems to be small—

再次造成災難性 撞擊的機會似乎很小

something like a 7 in a million chance.

大約是百萬分之七

However, we are facing the consequences of another kind of rapid climate change,

然而，我們正在面臨另一種 快速氣候變遷的後果

this time because of humanity's own emissions.

這次是人類自己的排放所造成

Animals are going extinct faster than ever in our history,

動物將會以史上 最快的速度步向絕種

and people are being displaced from their homes.

人被迫離開家園

But, unlike the dinosaurs,

與恐龍不同

we have the opportunity to avoid the large-scale devastation that will come

我們有機會避免大規模的毀滅

但若政府繼續維持現況 毀滅就勢必成真

if governments continue with the status quo.