Joel Levine: Why we need to go back to Mars

譯者: Ana Choi 審譯者: Adrienne Lin

I want to talk about 4.6 billion years of history

我想要用這18分鐘來聊一下

in 18 minutes.

四十六億年的歷史。

That's 300 million years per minute.

換算下來我一分鐘大約要跨越三億年。

Let's start with the first photograph NASA obtained

首先我們來看看美國太空總署

of planet Mars.

第一次拍攝火星的照片。

This is fly-by, Mariner IV.

這幅是水手4號飛過的拍攝。

It was taken in 1965.

是在1965年拍下的。

When this picture appeared,

當大家看到這幅照片,

that well-known scientific journal,

在那本著名的科學雜誌,

The New York Times, wrote in its editorial,

紐約時報知名的科學期刊的社論中寫到:

"Mars is uninteresting.

「火星是個無聊的地方。

It's a dead world. NASA should not spend

一片死寂，太空總署不應該花時間精力

any time or effort studying Mars anymore."

繼續研究火星。」

Fortunately, our leaders in Washington

幸運的是當時華盛頓的領袖以及

at NASA headquarters knew better

太空總署的總部比較瞭解狀況。

and we began a very extensive study

所以我們開始對這顆紅色的星球

of the red planet.

進行了大規模的研究。

One of the key questions in all of science,

在科學領域當中,有一個非常關鍵的問題:

"Is there life outside of Earth?"

「地球以外是有否生命存在？」

I believe that Mars is the most likely target

我認為火星是最有可能是在地球以外

for life outside the Earth.

發現存有生命的目標星球。

I'm going to show you in a few minutes

我會在接下來的幾分鐘內向大家展示

some amazing measurements that suggest

一些驚人的測量結果，

there may be life on Mars.

顯示火星上可能有生命存在。

But let me start with a Viking photograph.

但讓我首先說說這幅由維京1號拍攝的照片。

This is a composite taken by Viking in 1976.

這是一幅在1976年由維京1號探測器所拍攝的合成照片。

Viking was developed and managed at the

維京1號是在太空總署的蘭利研究中心

NASA Langley Research Center.

研製和主持的。

We sent two orbiters and two landers in the summer of 1976.

我們在1976年的夏天發射了兩顆軌道探測器和登陸探測器。

We had four spacecraft, two around Mars,

我們有四艘宇宙飛船，兩艘環繞着火星,

two on the surface --

兩艘降落在表面,

an amazing accomplishment.

這真是一個了不起的成就。

This is the first photograph taken from

這是第一幅

the surface of any planet.

在其他星球表面所拍攝的照片。

This is a Viking Lander photograph

這是一幅由維京著陸器所拍攝

of the surface of Mars.

火星表面的照片。

And yes, the red planet is red.

無錯，這個星球的確是紅色的。

Mars is half the size of the Earth,

火星大約是地球一半的尺寸。

but because two-thirds of the Earth is covered by water,

但是由於地球的表面三分之二都被水覆蓋着,

the land area on Mars

所以其實火星上的陸地面積

is comparable to the land area on Earth.

和地球上的都差不多。

So, Mars is a pretty big place even though it's half the size.

因此儘管火星只有地球一半的大小，它還是一個很大的地方。

We have obtained topographic measurements

我們得到了火星表面

of the surface of Mars. We understand

的地形尺碼。我們對它的海拔

the elevation differences.

分別有所理解。

We know a lot about Mars.

我們對火星已知道了不少。

Mars has the largest volcano in the solar system,

在太陽系裡火星擁有最大的火山，

Olympus Mons.

奧林帕斯山。

Mars has the Grand Canyon

火星有着太陽系裡的大峽谷，

of the solar system, Valles Marineris.

水手號谷。

Very, very interesting planet.

一個非常有意思的星球。

Mars has the largest

火星亦有在太陽系裡最大的

impact crater in the solar system,

撞擊坑，名為

Hellas Basin.

希臘平原。

This is 2,000 miles across.

這個撞擊坑有二千英里闊，

If you happened to be on Mars

若然你當時剛巧

when this impactor hit,

路過火星，

it was a really bad day on Mars.

那真正極是倒楣。

(Laughter)

（笑聲）

This is Olympus Mons.

這是奧林帕斯山。

This is bigger than the state of Arizona.

這比亞利桑那州更大。

Volcanoes are important, because volcanoes

火山是有重要性的，因為火山

produce atmospheres and they produce oceans.

製造大氣層，以至大氣層製造海洋。

We're looking at Valles Marineris,

我們現在來看看這個在太陽系

the largest canyon in the solar system,

最臣型的大峽谷，水手號谷的照片，

superimposed on a map of the United States,

疊放在一幅美國的地圖上，

3,000 miles across.

三千英里闊。

One of the most intriguing features about Mars,

根據國家科學學院所說，

the National Academy of Science says

火星其中一個耐人尋味的特徴，

one of the 10 major mysteries of the space age,

一個在太空時代列入十大奧秘之一，

is why certain areas of Mars

便是為何在火星上某些地區

are so highly magnetized.

是附磁性那麼高。

We call this crustal magnetism.

我們稱之為地殼磁性。

There are regions on Mars, where, for some reason --

在火星上有些地區，

we don't understand why at this point --

我們仍不明白為什麼

the surface is very, very highly magnetized.

那些地區的地殼是那麼高磁性。

Is there water on Mars?

火星上有水嗎？

The answer is no, there is no liquid water

答案是沒有, 今時今日在火星上

on the surface of Mars today.

是沒有液體水存在的。

But there is intriguing evidence

但卻有耐人尋味的證據顯示

that suggests that the early history of Mars

在火星歷史的早期

there may have been rivers

曾經可能有河流及

and fast flowing water.

快速流動的水存在。

Today Mars is very very dry.

今時今日火星卻是極之乾燥。

We believe there's some water in the polar caps,

我們相信在極地冰冠之處會有少量水份。

there are polar caps of North Pole and South Pole.

在北極和南極都有極地冰冠。

Here are some recent images.

這些是近期的圖片。

This is from Spirit and Opportunity.

這幅是攝於精神號和機遇號上。

These images that show at one time,

這些照片顯示火星表面在某一個時期

there was very fast flowing water on the surface of Mars.

曾經有過快速流動的水。

Why is water important? Water is important

為什麼水是重要？水當然是重要，

because if you want life you have to have water.

因為有水才有生命。

Water is the key ingredient

水是星球進化的

in the evolution, the origin of life on a planet.

關鍵因素，及生命的來源。

Here is some picture of Antarctica

這幅是南極的照片，

and a picture of Olympus Mons,

這幅是奧林帕斯山的照片，

very similar features, glaciers.

非常相似的特徵及冰川。

So, this is frozen water.

這是結了冰的水。

This is ice water on Mars.

這是火星上的冰水。

This is my favorite picture. This was just taken a few weeks ago.

我最喜歡這幅照片。攝於不過數星期前。

It has not been seen publicly.

還未公開於大衆。

This is European space agency

這是歐洲太空總署。

Mars Express, image of a crater on Mars

火星快車號拍下火星上的一個撞擊坑，

and in the middle of the crater

而在坑的中央

we have liquid water, we have ice.

我們發現了液體水及冰。

Very intriguing photograph.

非常奧妙的一幅照片。

We now believe that in the early history of Mars,

我們現在相信在火星歷史的早期，

which is 4.6 billion years ago,

那是四十六億年前。

4.6 billion years ago, Mars was very Earth-like.

在四十六億年前，火星的狀況和地球十分相似。

Mars had rivers, Mars had lakes,

火星有河流，有湖泊，

but more important Mars had planetary-scale oceans.

更重要是，火星上有恒星規模的海洋。

We believe that the oceans were in the northern hemisphere,

我們相信那些海洋曾位於北半球。

and this area in blue,

這些藍色的範圍

which shows a depression of about four miles,

顯示出這四英里的窪地

was the ancient ocean area

便是火星古遠時代

on the surface of Mars.

海洋的位置。

Where did the ocean's worth of water on Mars go?

那這麼多火星上的海水去了哪裡？

Well, we have an idea.

嗯，我們有一個想法。

This is a measurement we obtained a few years ago

幾年前從環繞火星軌道

from a Mars-orbiting satellite called Odyssey.

的一個衛星--火星奧德賽號--取得了一個測量，

Sub-surface water on Mars,

便是火星地下有水份

frozen in the form of ice.

被凍結成冰。

And this shows the percent. If it's a blueish color,

這個顯示百份率。呈然籃色的

it means 16 percent by weight.

按重量相等於百份之十六。

Sixteen percent, by weight, of the interior

百分之十六，按重量，

contains frozen water, or ice.

含有冰水，或冰。

So, there is a lot of water below the surface.

換句話說，火星地下層有很多水。

The most intriguing and puzzling measurement,

對我來說，我們在火星取得的

in my opinion, we've obtained of Mars,

最耐人尋味和令人費解的測量，

was released earlier this year

在今年年初經已在

in the magazine Science.

＜科學＞雜誌公開。

And what we're looking at is the presence of the gas methane,

我們有興趣的是有氣體存在--甲烷，

CH4, in the atmosphere of Mars.

CH4, 在火星上氣層中。

And you can see there are three distinct regions of methane.

你可以看到有三個不同的區域存有甲烷。

Why is methane important?

為什麼甲烷重要？

Because on Earth, almost all --

因為在地球，大至上全部，

99.9 percent -- of the methane

百分之九十九點九的甲烷

is produced by living systems,

都是由有生命的系統生產。

not little green men, but microscopic life

不是從綠色的小矮人，而是從地面上

below the surface or at the surface.

或地下層的微觀生物產生。

We now have evidence

我們現在有證據顯示

that methane is in the atmosphere of Mars,

火星氣層裡有甲烷，

a gas that, on Earth,

一種在地球上

is biogenic in origin,

由生命系統生產，亦是

produced by living systems.

生物起源的氣體。

These are the three plumes: A, B1, B2.

這便是那三瓣紊流，A, B1, B2。

And this is the terrain it appears over,

而這便是那氣體浮遊上空的地帶。

and we know from geological studies

由我們用對地質學的研究，

that these regions are the oldest regions on Mars.

這些地帶是火星上最古老的區域。

In fact, the Earth and Mars

事實上，地球和火星

are both 4.6 billion years old.

的年齡都是四十六億年歲。

The oldest rock on Earth is only 3.6 billion.

然而在地球上最古老的石頭只有三十六億歲。

The reason there is a billion-year gap

以我們對地質的研究

in our geological understanding

這時間上差距的

is because of plate tectonics,

原因是板塊構造論假说

The crust of the Earth has been recycled.

地球的地殼是被循環再用。

We have no geological record prior

我們沒有之前

for the first billion years.

的地球地質記錄。

That record exists on Mars.

但在火星上便有那記錄。

And this terrain that we're looking at

我們現在看到的地帶

dates back to 4.6 billion years

便有四十六億歲, 當時正是

when Earth and Mars were formed.

地球和火星形成的時候。

It was a Tuesday.

當日是星期二。

(Laughter)

(笑聲)

This is a map that shows

這幅地圖顯示

where we've put our spacecraft on the surface of Mars.

我們把飛船停放在火星表面的位置。

Here is Viking I, Viking II.

這是維京1號, 維京2號。

This is Opportunity. This is Spirit.

這是機遇號。這是精神號。

This is Mars Pathfinder. This is Phoenix,

這是火星探路者。這是我們剛剛在兩年前

we just put two years ago.

讓它飛往火星的鳳凰號。

Notice all of our rovers and all of our landers

看, 我們所有探測器和著陸器所

have gone to the northern hemisphere.

都是在北半球。

That's because the northern hemisphere

這是因為北半球是

is the region of the ancient

古遠時代

ocean basin.

海洋盆地的位置。

There aren't many craters.

在那裡不是有很多隕石坑。

And that's because the water protected the basin

因為那裡的水保護着盆地

from being impacted by asteroids and meteorites.

讓它不受到小行星和隕石轟擊。

But look in the southern hemisphere.

看看南半球。

In the southern hemisphere there are impact craters,

在南半球那裡有撞擊坑,

there are volcanic craters.

有火山坑。

Here's Hellas Basin,

這是希臘平原,

a very very different place, geologically.

一個地質非常不同的地方。

Look where the methane is, the methane is in a very

看看甲烷在哪裡, 甲烷是位於

rough terrain area.

一處十分不平坦的地區。

What is the best way to unravel

什麼是解開火星上的奧秘

the mysteries on Mars that exist?

最好的方式?

We asked this question 10 years ago.

我們在10年前已經提出這個問題。

We invited 10 of the top Mars scientists

我們邀請了10位頂級的火星科學家

to the Langley Research Center for two days.

前往蘭利研究中心兩天。

We addressed on the board

我們在黑板上發表

the major questions that have not been answered.

那些還沒有得到答案的主要問題。

And we spent two days deciding

我們花了兩天時間決定

how to best answer this question.

如何最有效地回答這個問題。

And the result of our meeting

而我們的會議結果

was a robotic rocket-powered airplane we call ARES.

是一艘我們稱之為ARES的火箭動力飛機。

It's an Aerial Regional-scale Environmental Surveyor.

是一艘空中區域規模的環境測量器。

There's a model of ARES here.

這是ARES的模型。

This is a 20-percent scale model.

百分之二十比例。

This airplane was designed at the Langley Research Center.

這艘飛機是在蘭利研究中心設計的。

If any place in the world

在世界上能建造一艘

can build an airplane to fly on Mars,

可以飛往火星的飛機的地方,

it's the Langley Research Center,

毫無疑問便是蘭利研究中心。

for almost 100 years

在近100年來，

a leading center of aeronautics in the world.

它是世界上航空中心的領導者。

We fly about a mile above the surface.

我們在表面約一英里以上飛行。

We cover hundreds of miles,

以450英里的時速,

and we fly about 450 miles an hour.

行駛數百英里。

We can do things that rovers can't do

我們可以做到探測器和著陸器

and landers can't do:

不能做的事情。

We can fly above mountains, volcanoes, impact craters;

我們可以在山脈，火山，撞擊坑的上空飛行。

we fly over valleys;

我們飛越山谷。

we can fly over surface magnetism,

我們可以飛越表面磁場，

the polar caps, subsurface water;

極地冰冠, 地下水。

and we can search for life on Mars.

我們可以在火星上尋找生命。

But, of equal importance,

當然，同樣重要的是，

as we fly through the atmosphere of Mars,

當我們穿越火星的大氣層，

we transmit that journey,

我們會傳遞這段旅程，

the first flight of an airplane outside of the Earth,

這第一次飛機在地球以外的飛行，

we transmit those images back to Earth.

我們會將這些圖像傳送回地球。

And our goal is to inspire the American public

我們的目標是激勵美國公眾,

who is paying for this mission through tax dollars.

通過稅收來支付這次使命的公眾。

But more important we will

但更重要的是我們要

inspire the next generation of scientists,

激發新一代科學家，

technologists, engineers and mathematicians.

技師，工程師和數學家。

And that's a critical area of national security

這是關鍵國家安全,

and economic vitality, to make sure

和經濟動力,

we produce the next generation

我們要確保生產下一代的

of scientists, engineers, mathematicians and technologists.

科學家，工程師, 數學家和技師。

This is what ARES looks like

這便是 ARES

as it flies over Mars.

飛越火星的模樣。

We preprogram it.

我們預先將它編程。

We will fly where the methane is.

我們會飛往甲烷所在之處。

We will have instruments aboard the plane

我們會帶同儀器

that will sample, every three minutes, the atmosphere of Mars.

來隔每三分鐘抽取火星大氣中的樣本。

We will look for methane

我們會尋找甲烷

as well as other gasses

以及由生命系統產生

produced by living systems.

的其他氣體。

We will pinpoint where these gases emanate from,

我們會準確查明這些氣體的來源。

because we can measure the gradient where it comes from,

因為我們可以測量它大概從何而來。

and there, we can direct the next mission

下一個任務我們便可以直接

to land right in that area.

飛到該地區降落。

How do we transport an airplane to Mars?

我們是如何將飛機運去火星？

In two words, very carefully.

五個字，非常小心地。

The problem is we don't fly it to Mars,

問題是，我們不要飛機直接飛至火星，

we put it in a spacecraft

我們會把它放在一首飛船內,

and we send it to Mars.

由飛船送它到火星。

The problem is the spacecraft's

但飛船的

largest diameter is nine feet;

最長直徑為九英尺。

ARES is 21-foot wingspan, 17 feet long.

而 ARES 是17英尺長, 翼展長度是21英尺。

How do we get it to Mars?

我們怎樣得把它運到火星呢？

We fold it,

我們會把它折疊，

and we transport it in a spacecraft.

再將之放入一個大氣圈,

And we have it in something called an aeroshell.

然後由飛船把它運送。

This is how we do it.

就是這樣。

And we have a little video that describes the sequence.

我們還有一段短短的視頻來演示所談及的程序。

Video: Seven, six. Green board. Five, four, three, two, one.

視頻：綠板。 5,4,3,2,1。

Main engine start, and liftoff.

主要發動機啟動。升空。

Joel Levine: This is a launch from the Kennedy Space Center in Florida.

喬爾•列維:「這是從佛羅里達州肯尼迪航天中心的發射。

This is the spacecraft taking nine months

這是飛船前往火星

to get to Mars.

9個月之旅。

It enters the atmosphere of Mars.

它正在進入火星大氣層。

A lot of heating,

許多熱氣。

frictional heating. It's going 18 thousand miles an hour.

一萬八千英里時速摩擦產生的熱氣。

A parachute opens up to slow it down.

一個降落傘會打開將它慢慢降速。

The thermal tiles fall off.

然後隔熱瓦會脫落。

The airplane is exposed to the atmosphere for the first time.

這是飛機第一次暴露在大氣中。

It unfolds.

接著它會展開。

The rocket engine begins.

火箭引擎會開始啟動。

We believe that in a one-hour flight

我們相信，以一個小時的飛行旅程

we can rewrite the textbook on Mars

我們便可以重寫火星的教科書。

by making high-resolution measurements of the atmosphere,

以高分辨率測量大氣，

looking for gases of biogenic origin,

尋找生物起源的氣體，

looking for gases of volcanic origin,

尋找火山氣體來源，

studying the surface, studying the magnetism

研究表面，研究我們不明白

on the surface, which we don't understand,

的表面磁場,

as well as about a dozen other areas.

以及其他十幾個領域。

Practice makes perfect.

熟能生巧。

How do we know we can do it?

為什麼我們這樣有信心呢?

Because we have tested ARES model,

因為我們已經將 ARES 通過測試，

several models in a half a dozen wind tunnels

八年來在美國航天局蘭利研究中心，

at the NASA Langley Research Center for eight years,

用六個模型在具有

under Mars conditions.

火星條件的風洞測試。

And, of equal importance

再者，同樣重要地,

is, we test ARES in the Earth's atmosphere,

我們在地球的大氣層測試 ARES，

at 100,000 feet,

在10萬英尺上空，

which is comparable to the density and pressure

這是相比於將在火星飛行的氣壓

of the atmosphere on Mars where we'll fly.

和密度非常類似。

Now, 100,000 feet, if you fly cross-country to Los Angeles,

試想想，如果你飛往洛杉磯

you fly 37,000 feet.

只不過37,000英尺。

We do our tests at 100,000 feet.

我們的測試高度是10萬英尺。

And I want to show you one of our tests.

現在我想給你們放映我們的一個測試。

This is a half-scale model.

這是一個半比例模型。

This is a high-altitude helium balloon.

這是一個高空氦氣氣球。

This is over Tilamook, Oregon.

這是在蒂拉穆克，俄勒岡州上空。

We put the folded airplane on the balloon --

我們把已折疊的飛機放在氣球上。

it took about three hours to get up there --

花了大約三個小時才到達那高空。

and then we released it on command

然後在103000英尺上空，

at 103,000 feet,

我們發佈命令它展開。

and we deploy the airplane and everything works perfectly.

我們部署飛機的過程一切無阻。

And we've done

我們已經進行了

high-altitude and low-altitude tests,

高海拔和低海拔的測試，

just to perfect this technique.

來熟練這種技術。

We're ready to go.

我們已經一切準備就緒。

I have a scale model here.

我在這裡的是一個比例模型。

But we have a full-scale model

但在美國航天局蘭利研究中心內，

in storage at the NASA Langley Research Center.

我們已存放了真正比例的模型。

We're ready to go. All we need is a check from NASA headquarters

我們已經準備好。我們只需要美國航空航天局總部的一張支票

(Laughter)

(笑聲)

to cover the costs.

來支付費用。

I'm prepared to donate my honorarium for today's talk

我已準備為為這一個使命捐出

for this mission.

我今天談話的酬金。

There's actually no honorarium for anyone for this thing.

其實這件事情任何人都是有沒有酬金的。

This is the ARES team;

這是 ARES 的部隊。

we have about 150 scientists, engineers;

我們有大約150名科學家，工程師，

where we're working with Jet Propulsion Laboratory,

我們正在努力地與噴氣推進實驗室 (JPL),

Goddard Space Flight Center,

戈達德太空飛行中心,

Ames Research Center and half a dozen major universities

Ames 研究中心, 以及其他重點大學

and corporations in developing this.

和機構在共同發展這個重任。

It's a large effort. It's all at NASA Langley Research Center.

這是一個很大的任務。而一切都在美國航空航天局總部蘭利研究中心實現。

And let me conclude by saying

讓我最後說說,

not too far from here,

離這裡不太遠，

right down the road in Kittyhawk, North Carolina,

沿著這條道路, 北卡羅萊納州的基蒂霍克,

a little more than 100 years ago

稍多於100年前,

history was made

便創造了歷史,

when we had the first powered flight of an airplane on Earth.

當我們第一次在地球上有動力飛行的飛機。

We are on the verge right now

我們現在正在歷史的邊緣,

to make the first flight of an airplane

讓第一首在地球大氣層外

outside the Earth's atmosphere.

飛航的飛機。

We are prepared to fly this on Mars,

我們已準備將它飛往火星,

rewrite the textbook about Mars.

改寫火星的教科書。

If you're interested in more information,

如果你有興趣了解更多資料,

we have a website that describes this exciting

我們有一個網站, 裡面描述了這一項奇妙和令人興奮的任務，

and intriguing mission, and why we want to do it.

以及任務的原因。

Thank you very much.

非常感謝大家。

(Applause)

(掌聲)