Neil: And I'm Neil. Sophie, did you see the beautiful sky last night?

我是尼爾。蘇菲，你昨晚有看到美麗的星空嗎?

Sophie: No, I went to bed early. Why?

沒，我很早就睡了。怎麼了？

Neil: I was wondering if there was life out there.

我在想外星生物是否真的存在

Sophie: You mean life on other planets? That's just science fiction, Neil.

你是說在其他星球上嗎? 那根本是科幻啦

Neil: It isn't! People are fascinated by life on other planets for a good reason.

才怪！我們對外星生物如此著迷不是沒有原因的

Sophie: You believe in little green men?

你相信小綠人喔？

Neil: Not necessarily... but possibly.

也不是...但很可能存在啊

Sophie: Well, Mars is our closest neighbour in the solar system

太陽系中就屬火星最靠近我們了

and the subject of today's show.

也就是今天的主題

And that brings me on to our usual quiz question. How long is a day on Mars?

接著來到每日一問: 火星上的一天到底多久呢?

Is it about... a) 5 hours? b) 25 hours?

是 a) 5小時, b)25小時

Or c) 45 hours?

還是 c) 45小時?

Neil: And I think it must be c) 45 hours. Things are weird on other planets.

我猜 c) 45小時，別的星球一定跟我們不一樣

And Mars is further from the sun than us... Mars may be our closest neighbour, but it's

火星距太陽比我們還遠...就算火星是我們最近的鄰居

hardly in our backyard, is it?

也並非近到如自家後院

Sophie: It is in astronomical terms, Neil

尼爾，要用天文學角度來看

it's visible to the naked eye

火星可用肉眼看見

meaning without using instruments

也就是不需要藉助天文儀器

and it's reachable by spacecraft.

而且太空船也到得了

Well, we'll find out later on in the show whether you got the answer right or not.

我們待會再來看你有沒有答對

Now can you tell me Neil why people like you get excited about the possibility of life on Mars?

現在倒是要請你說說 為何許多人跟你一樣 提到火星上可能有生物 就特別興奮呢？

Neil: Well, Mars is similar to the Earth in some important ways

這個嘛...火星很多方面像地球

which means if life developed on our planet, why not Mars?

這代表如果地球有物種演化，火星上一定也有

Sophie: That's true. Its temperature is in the right zone

沒錯，火星氣溫剛剛好

not too hot and not too cold.

不會太熱 也不會太冷

But actually we could find Mars pretty cold

不過火星對我們而言可能有點冷

an average temperature would be around minus 63 degrees Celsius compared to Earth's 14 degrees Celsius.

平均溫度約攝氏負63度，地球才不過14度而已

It's also very arid – or dry.

太乾旱，也就是太乾燥

Neil: And it needs to be wet for life to develop, doesn't it?

生物需要雨水滋潤才能成長，不是嗎?

Sophie: That's right. Many scientists think that liquid water is essential for life!

沒錯，科學家相信有液態水就有生命!

But there may have been water on the surface of Mars in the past.

但很可能古老的火星地表上有水

And recent research suggests that there may be water underground.

新的研究也指出火星地下有水

Let's hear some more about this from Professor John Zarnecki,

讓我們來聽聽約翰·札內基教授怎麼說

who teaches Space Science at The Open University.

札內基教授在空大教太空科學

John Zarnecki: We are now seeing that in fact Mars probably does have water – not liquid water

現在我們知道在火星上的確有水–但不是液態水

that there is ice just below the surface

是地表下的冰

and there's even just recently tantalizing evidence that perhaps water does flow periodically...

誘人的新證據也指出，那裡的水可能週期性地流動

Now, and also coupled with the fact that here on Earth we're finding that life in very primitive form

再加上我們已發現地球上最原始的生物

exists in the most extreme environments, these are the so called 'extremophiles'

存在最極端的環境，它們也被稱作嗜極端菌

that exist at the bottom of the oceans...

存活在海洋最底層

So life is much, much tougher.

那裡存活不易

Neil: What does tantalizing mean, Sophie?

蘇菲，tantalizing是什麼意思啊?

Sophie: It means something you want that's almost, but not quite, within reach.

意思是你最想要的東西還沒完全到手，就差那麼一點

So, scientists would love to think water flows on Mars

所以說，科學家相信火星上有水的足跡

but the evidence isn't strong enough for this to be certain.

但證據卻還不夠充足

The other interesting point the professor makes

另一個教授提出的有趣的點是

is that life may exist in the very harsh Martian environment

在非常嚴峻的火星環境裡，仍有生物存在

because primitive life exists in extreme places on Earth.

因為最原始的生物就生存在地球最極端之處

Neil: Extremophiles are organisms – or small creatures

嗜極端菌是一群生物，或微生物

that live in very extreme environments

生長在極端環境

and can survive conditions that would kill most other organisms.

能夠應付別的生物無法存活的極端氣候

But on Mars they would be living underground

不過在火星上，牠們活動範圍是地底下

because the radiation – or light and heat

因為太陽輻射– 光或熱

from the Sun would kill any organisms living on the surface of the planet.

會將地表活動的生物殺死

So why doesn't the Sun's radiation kill us then, Sophie?

那為何太陽輻射沒把我們殺死?

Sophie: The Earth has a strong magnetic field created by its hot molten core or centre ...

地球有強大的磁場，由地心熔鐵產生

and this protects us from the Sun's harmful solar winds.

保護我們免於太陽的粒子風暴

Neil: And what about Mars - why doesn't it have a magnetic field?

那火星為甚麼就沒有磁場?

Sophie: It used to ... 4 billion years ago.

曾有過啊...40億年前

It's possible that a massive collision with an asteroid

很可能一個大規模的小行星碰撞

might have heated up Mars's core, disrupting the magnetic fields.

讓火星的核心變熱而破壞了磁場

Neil: And if you disrupt a process you stop it from continuing normally.

破壞過程也就是你讓程序無法正常進行

Now, to return to the subject of collisions, Sophie, I have something very interesting to tell you.

再回來談小行星碰撞，蘇菲，我告訴你一件有趣的事

Sophie: Yes?

咦?

Neil: A meteorite – or a piece of rock from outer space – might've crashed into the Earth millions of years ago.

很有可能幾百萬年前，隕石–來自外太空的石頭，撞擊了地球

That meteorite might have contained Martian life forms.

那顆隕石就可能潛藏火星生物

So we might be descended from Martians!

因此我們可能是火星人後代耶!

Sophie: That's actually an interesting idea, Neil.

那個想法真是有趣啊，尼爾

But let's listen to Professor John Zarnecki talking about interplanetary life.

但讓我們來聽聽約翰·札內基教授對星球生物的看法

John Zarnecki: If we do find traces of life on Mars we don't know, do we

即使我們找到火星生物的足跡，我們也無法確認

whether it evolved independently or was it perhaps seeded from Earth.

那是自行演化，或是從地球過去的

It is possible that life forms from Earth travelled to Mars and perhaps existed there

很可能是地球物種到了火星上活了下來

or the other way round.

或相反的情況

Neil: So life on Mars may have evolved – or developed – on its own.

所以說火星物種可能是自行演化或發展的囉

Or it might have arrived from Earth in a lump of rock... Or the other way round!

或是從地球的一塊大石頭飛過去...或剛好相反!

So Martians might be humans or we might be Martians!

所以火星人可能是地球人, 或我們是火星人!

One big interplanetary happy family, Sophie!

一個快樂的大星際家族!

Sophie: Well Neil, let's hope you stay happy after you hear the answer to today's quiz question.

希望你聽到今日一問的正解時也會如此開心啊，尼爾

I asked: How long is a day on Mars? Is it ... a) 5 hours? b) 25 hours? Or c) 45 hours?

我問火星上的一天多長，是a) 5小時 b) 25小時 還是 c) 45小時呢?

Neil: And I said c) 45 hours – they must have a long day over there.

我說 c) 45小時，那裡的一天一定很長

Sophie: And you were ... wrong!

啊哈你錯了!

The correct answer is b) because a day on Mars is slightly longer than here on Earth

正解是 b) 因為火星上的一天只比地球的長一點點

it's 25 hours.

25小時

Anyway, can we at least hear the words we learned today?

好啦，我們可以來看今天學的生字了嗎?

Neil: They are:

有

the naked eye

肉眼

arid

乾旱

tantalizing

誘人的

extremophiles

嗜極端菌

organisms

生物

radiation

輻射

core

核心

disrupt

破壞

meteorite

隕石

evolved

演化的

Sophie: Well, that's the end of today's 6 Minute English.

那就是今日的6分鐘學英語

Join us again soon!

下次再會!

Both: Bye.

再見