The most Martian place on Earth | Armando Azua-Bustos

譯者: Kelly Yau 審譯者: Helen Chang

This is a picture of a sunset on Mars

這張是火星上的日落照片，

taken by NASA's Curiosity rover in 2013.

由美國太空總署「好奇號」 於 2013 年拍攝的。

Mars is a very cold planet,

火星是個非常寒冷的星球，

flooded with high levels of UV radiation

受強烈紫外線覆蓋，

and extremely dry.

而且極為乾燥。

In fact, Mars is considered to be too dry for life as we know it.

事實上，我們認為 火星太乾燥，沒有生物存在。

I'm an astrobiologist.

我是天體生物學家，

I try to understand the origin of life on Earth

嘗試去了解地球上生物的起源，

and the possibilities of finding life

以及在宇宙中其他地方

elsewhere in the universe.

找尋到生物的可能性。

People sometimes ask me,

有時候，大家會問我，

how can you be an astrobiologist

如果你沒有自己的太空船，

if you don't have your own spaceship?

又怎算是天體生物學家呢？

Well, what I do is that I study life

其實，我專注在地球尋找

in those environments on Earth

與其他星球相似的環境，

that most closely resemble other interesting places in the universe.

並研究該自然環境的生物。

All life on Earth requires water,

地球上所有生物賴以水為生，

so in my case I focus on the intimate relationship

因此我專於研究 水和生命密切的關係，

between water and life

in order to understand

從而去了解

if we could find life in a planet as dry as Mars.

我們能否在像火星般

乾旱的星球找到生物。

But since I do not have the 2.5 billion dollars

由於我沒有 25 億美元資金

to send my own robot to Mars,

把自己的機械人送到火星，

I study the most Martian place on Earth,

因此研究地球上與火星最似的地方：

the Atacama Desert.

阿他加馬沙漠。

Located in northern Chile,

位於智利北部，

it is the oldest and driest desert on Earth.

是地球上最古老和乾旱的沙漠。

To give you an idea of how dry it is,

給你一個例子，就明白有多乾燥。

consider here in Vancouver it rains over 1,000 millimeters of rain every year.

試想，溫哥華這裡 年降雨量超過 1000 毫米；

In the Atacama, there are places with no reported rains

過去四百年，阿他加馬有些地方

從來沒有降雨記錄。

in the last 400 years.

How do I know this?

為什麽我會知道？

Well, because I was born and raised in the Atacama --

因為我在阿他加馬出生和長大。

(Laughter)

（笑聲）

So I had a unique advantage

因此，當我對沙漠展開研究時，

when I started studying this desert.

有得天獨厚的優勢。

So let me tell you guys a few fantastic examples

就讓我向各位分享

he has found

「他」所找到的驚人發現，

on how life has adapted to live with almost no water at all.

即生物在乾旱地方如何能完全適應。

One of my first findings was in the entrance of a cave

我的早期發現之一 是在某個洞穴的入口，

facing the Pacific Ocean.

該洞穴面向太平洋。

In this place, we reported a new type of microalgae

在這裡，我們發現一類新型微藻，

that grew only on top of the spiderwebs that covered the cave entrance.

只長在覆蓋洞穴入口的蜘蛛網上。

Have you ever seen a spiderweb early in the morning?

你有否在大清早見過蜘蛛網？

It's covered with dew,

蜘蛛網被露水覆蓋。

so this microalgae learned that in order to carry photosynthesis

因此微藻為了

在地球上最乾旱的沙漠 進行光合作用，

in the coast of the driest desert on Earth,

they could use the spiderwebs.

學會借蜘蛛網。

So here they may access the water from the fogs

微藻透過每清早落在 蜘蛛網上的露水吸取水份。

that regularly cover these areas in the morning.

In another cave, we found a different type of microalgae.

我們在另一個洞穴發現別種微藻，

This one is able to use ocean mist as a source of water,

這種微藻以海洋帶來的霧氣為水源，

and strikingly lives in the very bottom of a cave,

而且很驚人地生長於洞穴底處，

so it has adapted to live with less than 0.1 percent

因此它習慣生存在光源只有

普通植物所需光源 0.1% 的地方。

of the amount of light that regular plants need.

These type of findings suggest to me that on Mars,

這些研究結果意味著在火星

we may find even photosynthetic life inside caves.

也可能在洞穴找到植物。

And by the way, that's me.

順帶一提，這個是我。

(Laughter)

（笑聲）

Now, for almost 15 years this region of Yungay, discovered by NASA,

美國太空總署發現位於秘魯 永蓋的這個區域至今已有 15 年，

was thought to be the driest place of this desert,

原被視為這片沙漠中最乾旱的地方。

but I knew that it was not.

但以我所知，這裡並不最為乾旱。

How? You already know the answer.

我怎會知道？你已經知道答案：

Because I was born and raised in this desert.

因為我在這沙漠出生和成長。

So I remembered that I usually see fogs in Yungay,

我記得經常在永蓋看到霧。

so after setting sensors in a number of places,

後來我在別的地方設置感應器，

where I remember never seeing fogs or clouds,

因為我從未在那裡見過霧和雲，

I reported four other sites much drier than Yungay,

我發現四個比永蓋還要乾旱的地方。

with this one, María Elena South,

這裡，瑪莉亞埃琳娜南區

being the truly driest place on Earth,

是地球上真正最乾旱的地方，

as dry as Mars,

跟火星一樣乾旱。

and amazingly, just a 15-minute ride

驚喜的是，這裡 距離我出生的煤礦小鎮

from the small mining town where I was born.

只有十五分鐘路程。

Now, in this search, we were trying to actually find the dry limit

在研究中，我們嘗試找出

地球上生物耐旱的極限。

for life on Earth,

a place so dry that nothing was able to survive in it.

在這個乾旱到寸草不生的地方。

But even here, well hidden underground,

儘管如此，

we found a number of different microorganisms,

我們在地底發現到多種微生物，

which suggested to me that similarly dry places, like Mars,

這個結果提醒我， 即使乾旱如火星的地方，

may be inhabited.

也可能住著生物。

We even have some preliminary evidences

我們甚至已有初步證據，

that these microorganisms may still be active

證明微生物在乾旱情況下仍活躍，

in the desiccated state,

like walking mummies all around us,

就像木乃伊在我們身邊走動一樣。

and that they may be using UV radiation as a source of energy.

微藻有可能以紫外線作為能源。

If confirmed, this would have a huge impact on our definition of life,

假如得到證實， 將改變我們對生物的定義，

on how we look for life elsewhere in the universe.

以及在其他星球尋找生物的看法。

Due to its clear skies, by 2020,

由於這裡天氣晴朗， 到了 2020 年，

60 percent of the biggest telescopes on Earth

地球上百分六十的大型望遠鏡

will be located in the Atacama,

將會設於阿他加馬。

and while everyone else will be looking among the stars

當每個人在望著星星，

to answer the question, "Are we alone?"

問：「地球是唯一有生物的地方嗎？」

I will be looking down to the ground

我會在家中後院，望著地下，

searching for this same answer

尋找同一答案。

in my own backyard.

Thank you.

謝謝。

(Applause)

（拍掌）