is one of the most intriguing quests of our time.

是我們這個時代最耐人尋味的任務之一。

From UFOs and little green aliens

從UFO和綠色小外星人

to the possibility of life in the underground aquifers of Mars,

到火星地下含水層中存在生命的可能性。

there's no end to speculation as to what form this life could take

對這種生命可能採取的形式的猜測是無止境的。

and how it could have developed.

以及它可能如何發展。

There's even a raft of videos on the internet

互聯網上甚至有很多視頻

speculating that aliens must have visited

猜測外星人一定訪問過

ancient civilisations on Earth,

地球上的古代文明。

because otherwise, how else could the Mayans have built

因為否則，瑪雅人怎麼可能建造出

their incredible temples.

他們令人難以置信的寺廟。

Spoiler - there is no evidence at all for this.

劇透--根本沒有證據證明這一點。

Frankly, if I was a Mayan stoneworker from 250AD,

坦率地說，如果我是公元250年的瑪雅石匠。

I would find it deeply insulting.

我會覺得這是對我的深深侮辱。

But a more interesting theory, and one which has more credibility,

但一個更有趣的理論，也是一個更有可信度的理論。

is that of panspermia.

是泛生論的觀點。

That life exists throughout the Universe

宇宙中存在生命

and can be transported through space from one location to another.

並能通過空間從一個地方傳送到另一個地方。

Although it's certainly not proven,

雖然這肯定沒有得到證實。

a team of prominent scientists from MIT and Harvard

一個由麻省理工學院和哈佛大學的著名科學家組成的團隊

have been working on a theory that some form of life

一直在研究一種理論，即某種形式的生命

was actually delivered to Mars in this way.

實際上是以這種方式被送到火星上的。

Here's what we know.

以下是我們知道的情況。

Life is incredibly adaptable, just look at the way our own species

生命具有令人難以置信的適應性，只要看看我們自己的物種如何

has managed to thrive across the globe,

已經成功地在全球範圍內茁壯成長。

and microorganisms, such as archaea and bacteria,

和微生物，如古菌和細菌。

over the course of millions of years of evolution

在數百萬年的進化過程中

have been able to modify themselves

已經能夠修改自己

in order to adapt to a vast range of conditions.

以適應廣泛的條件。

This means that today there are microbes that can survive

這意味著，今天有一些微生物可以生存在

on a variety of diets - sulphur, ammonia, the metal manganese,

在各種飲食中--硫、氨、金屬錳。

and in the presence or absence of oxygen.

並在有或沒有氧氣的情況下。

Some even survive in the most extreme conditions Earth has to offer.

有些人甚至在地球所能提供的最極端條件下生存。

Pyrococcus furiosus (don't you love that name?)

憤怒的火球菌（你不喜歡這個名字嗎？）

thrives in hydrothermal vents on the seafloor.

在海底的熱液噴口中茁壯成長。

It's optimal growing temperature is 100 degrees Celsius.

它的最佳生長溫度是100攝氏度。

Whereas the Antarctic psychrobacter frigidicola

而南極的精神細菌frigidicola

prefers things decidedly chillier.

他喜歡更冷的東西。

You can also find these extremophiles hanging out in hot acid,

你還可以發現這些極端的嗜熱菌在熱酸中閒逛。

or surviving desiccation in salt-crusted deserts.

或在鹽殼化的沙漠中生存的乾燥。

And some of these microbes can even deal with several extremes at once.

而這些微生物中的一些甚至可以同時處理幾個極端的情況。

Deinococcus radiodurans can be found in both hot springs

放射性球菌可在兩種溫泉中發現

and Antarctic soil,

和南極的土壤。

survive desiccation, and is one of the most radiation-resistant

在乾燥中生存，並且是抗輻射能力最強的動物之一。

organisms we know.

我們知道的生物體。

So these extremophiles are probably the most oven-ready organisms

是以，這些極端嗜水生物可能是最適合烘烤的生物體

to survive and, potentially, colonise the hostile environments

以求得生存，並有可能在惡劣的環境中進行殖民。

of other planets and moons,

的其他行星和衛星。

as long as there's liquid water at least some of the time.

只要至少在某些時候有液態水，就可以。

How would these tiny microbes

這些微小的微生物將如何

even make the journey to these other places?

甚至去這些其他地方的旅程？

Well, the easiest way is to hitch a ride with us

好吧，最簡單的方法是搭我們的便車

as we explore our solar system and beyond.

當我們探索我們的太陽系和其他地方時。

Tersicoccus phoenicis is a becterium

嗜血桿菌是一種細菌

discovered in Nasa spacecraft cleaning facilities.

在美國國家航空航天局的航天器清潔設施中發現。

Could we have already accidentally introduced bacteria from Earth

我們是否已經意外地從地球上引入了細菌？

to the Moon and Mars?

到月球和火星？

Another possible way

另一種可能的方式

for these microbes to get around the solar system

為這些微生物在太陽系中游走

is by hitchhiking on meteoroids.

是通過搭上流星體的便車。

When these crash on a planet,

當這些東西在一個星球上崩潰時。

rocks and debris are shot into space, generating more meteoroids.

岩石和碎片被射入太空，產生了更多的流星體。

So far, 313 Martian meteorites have been found on Earth,

到目前為止，地球上已經發現了313塊火星隕石。

and an Earth rock was also found on the Moon,

並且在月球上也發現了一塊地球岩石。

therefore we know there has been interplanetary transfer of rocks.

是以，我們知道存在著行星間的岩石轉移。

Once in space, the cold and lack of oxygen

一旦進入太空，寒冷和缺氧的環境下

are easily dealt with

容易處理

by our hardy voyagers,

由我們堅韌的航行者。

and even regular bacteria can enter a state of dormancy

甚至普通細菌也能進入休眠狀態

under extreme conditions,

在極端條件下。

creating thick-walled internal safe rooms for their DNA called spores.

為它們的DNA創造厚壁的內部安全室，稱為孢子。

Heat, cold, acid, drought and UV-resistant packets

耐熱、耐寒、耐酸、耐旱、耐紫外線的包裝材料

of bacterial DNA voyaging through space.

細菌的DNA在太空中航行。

Another big problem is that space is brimming with ionising radiation

另一個大問題是，太空中充滿了電離輻射

that rips DNA to shreds.

將DNA撕成碎片。

Not a problem for deinococcus. Clumps of this little fellow

對脫氧核糖核酸來說，這不是一個問題。這個小傢伙的團塊

have survived three years of exposure to outer space.

經歷了三年的外太空暴露後，已經倖存下來。

Others have survived up to six years in spore form.

還有一些以孢子形式存活了六年之久。

Yet another problem is time.

然而，另一個問題是時間。

Space is big,

空間是很大的。

so travelling anywhere takes a long time.

是以，到任何地方旅行都需要很長的時間。

That said, in 2020, Japanese scientists revived bacteria

也就是說，在2020年，日本科學家恢復了細菌

that had laid dormant at the bottom of the ocean

蟄伏在海底的 "小魚"。

for 100 million years.

1億年來。

So perhaps the extraordinary distances aren't such a problem

是以，也許非凡的距離並不是一個問題。

for these tiny space travellers.

為這些微小的太空旅行者。

The final step is surviving the crash landing onto your new home.

最後一步是在墜落到你的新家時倖存下來。

And bacteria have been shown to be able to do just that...

而細菌已被證明能夠做到這一點......

As long as they are in deep fractures in the cosmic rock.

只要它們是在宇宙岩石的深層裂縫中。

So it's entirely possible that microbial life

所以完全有可能出現微生物生命

has already travelled to somewhere like Mars.

已經旅行到像火星這樣的地方了。

Conditions there were remarkably similar to Earth

那裡的條件與地球非常相似

3.8 billion years ago.

38億年前。

Could these extremophile microbes

這些極端嗜好的微生物會不會

have already colonised the underground aquifers of Mars?

已經對火星的地下水層進行了殖民統治？

If they're already there,

如果他們已經在那裡了。

have they adapted to their new environment?

他們是否適應了新的環境？

Or maybe life on Earth actually originated on Mars

或者，地球上的生命實際上起源於火星

then travelled over to our planet?

然後到我們的星球上旅行了？

They may not be little green aliens,

他們可能不是綠色的小外星人。

or intelligent life as we understand it,

或我們所理解的智能生命。

but the very possibility that life could have transferred

但是，生命可能已經轉移的可能性

across the solar system and beyond is deeply intriguing.

跨越太陽系和超越太陽系，這一點深深地吸引著人們。

And as the James T Webb telescope begins its search

隨著詹姆斯-T-韋伯望遠鏡開始搜索

for tell-tale signs of distant life on other planets,

尋找其他星球上遙遠生命的蛛絲馬跡。

could we perhaps find out that life is far more inevitable

我們是否可以發現，生命是更不可避免的

than we once thought?

比我們曾經認為的要好？