It has a dense atmosphere

想像一個地形多樣的世界。

within which winds sweep across its surface

它有一個高密度的大氣層，

and rain falls.

有風席捲表面和降雨。

It has mountains and plains,

它有高山、平原、河流、湖泊和海洋，

rivers, lakes and seas,

也有沙丘和一些隕石坑。

sand dunes and some impact craters.

聽起來很像地球， 對吧?

Sounds like Earth, right?

這是泰坦。

This is Titan.

1981 年 8 月，

In August 1981,

航海家二號拍攝了這張 土星最大衛星的影像。

Voyager 2 captured this image of Saturn's largest moon.

航海家的任務走得比以往更遠，

The Voyager missions have traveled farther than ever before,

將太陽系和更遠的地方

making the solar system and beyond

都畫到我們的地圖上。

part of our geography.

但是這個影像，這個朦朧的月亮，

But this image, this hazy moon

點醒了我們它仍有許多神秘與未知。

was a stark reminder of just how much mystery remained.

當旅行者飛過它時， 我們對它的瞭解突然大增，

We learned an exponential amount as the Voyagers flew by it,

但我們仍不知道 籠罩在這大氣之下的面貌。

and yet we had no idea what lay beneath this atmospheric blanket.

它是否像觀測到的 其他土星和木星的衛星，

Was there an icy surface with landforms like those of the other moons

表面結冰或有相似的地貌，

that had been observed at Saturn and Jupiter?

或只是一片液態甲烷的汪洋 覆蓋整個表面？

Or perhaps simply a vast global ocean of liquid methane?

被籠罩在陰霾下的泰坦表面 是個巨大的謎團。

Shrouded by the obscuring haze,

卡西尼－惠更斯號 這對繞行土星和登陸泰坦的搭檔

Titan's surface was a huge, outstanding mystery

於 1997 年發射，

that Cassini-Huygens, an orbiter lander pair launched in 1997,

任務就是要解開這個謎團。

was designed to solve.

它們在 2004 年到達後，

After arrival in 2004,

卡西尼號最初傳回的泰坦表面影像

the early images Cassini sent back of Titan's surface

更加深了它的魅力。

only heightened the allure.

我們花了幾個月時間才明白 在泰坦表面上我們看到的到底是什麼；

It took months for us to understand what we were seeing on the surface,

例如我們稱為貓爪痕的

to determine, for example,

那些剛開始無法分辨的深色條紋，

that the dark stripes,

其實是有機沙堆成的沙丘。

which were initially so unrecognizable that we referred to them as cat scratches,

在卡西尼號研究土星、 土星環和其衛星的十三年中，

were actually dunes made of organic sand.

我們有幸從對泰坦表面幾乎一無所知

Over the course of the 13 years Cassini spent studying Saturn

到瞭解它的地質

and its rings and moons,

以及它的大氣對表面地形的影響，

we had the privilege

甚至在泰坦地底深處 是什麼也有些線索。

of going from knowing almost nothing about the surface of Titan

事實上，泰坦是幾個 太陽系的海洋世界之一。

to understanding its geology,

這些海洋世界都是 火星軌道和小行星帶之外

the role the atmosphere plays in shaping its surface,

寒冷的外太陽系中的衛星。

and even hints of what lies deep beneath that surface.

它們的表面下是液態水的海洋。

Indeed, Titan is one of several ocean worlds,

泰坦地下海洋的水

moons in the cold outer solar system

可能是地球上所有河流、湖泊、海洋 全部水量的 10 倍以上。

beyond the orbits of Mars and the asteroid belt

泰坦表面還有不尋常的湖泊和海洋，

with immense liquid water oceans beneath their surfaces.

裡面都是液態甲烷和乙烷。

Titan's interior ocean may have more than 10 times as much liquid water

海洋世界是太陽系中 最迷人的一些地方，

as all of the Earth's rivers, lakes, seas and oceans combined.

我們才剛開始探索它們。

And at Titan, there are also exotic lakes and seas

這是蜻蜓號。

of liquid methane and ethane on the surface.

在約翰霍普金斯應用物理實驗室裡，

Ocean worlds are some of the most fascinating places

我們正在為美國太空總署的 新疆界計劃打造這個任務。

in the solar system,

蜻蜓號計劃於 2026 年發射， 2034 年到達泰坦。

and we have only just begun to explore them.

它是一個旋翼登陸艇，

This is Dragonfly.

大小與火星探測車或小型汽車相近。

At the Johns Hopkins Applied Physics Laboratory,

泰坦高密度的大氣層，加上低重力，

we're building this mission for NASA's new Frontiers program.

使它成為很適合飛行的地方。

Scheduled to launch in 2026 and reach Titan in 2034,

蜻蜓號的設計就是要 能在泰坦大氣中飛行。

Dragonfly is a rotorcraft lander,

蜻蜓號實際上是一個八旋翼飛行器，

similar in size to the Mars rovers or about the size of a small car.

裡面是個行動實驗室，

Titan's dense atmosphere, combined with its low gravity,

可以帶著它所有的科學儀器飛來飛去。

make it a great place to fly,

蜻蜓號將以非常獨特的方式調查泰坦，

and that's exactly what Dragonfly is designed to do.

仔細研究它的氣候和地質，

Technically an octocopter,

甚至從表面採集樣本，

Dragonfly is a mobile laboratory that can fly from place to place

瞭解它們的組成。

taking all of its scientific instruments with it.

總之，蜻蜓號將花費 大約三年時間探索泰坦，

Dragonfly will investigate Titan in a truly unique way,

仔細測試它的化學成分，

studying details of its weather and geology,

觀察大氣層及其如何與地表相互作用，

and even picking up samples from the surface

甚至聆聽泰坦地殼中的地震，

to learn what they're made of.

或應該說是「泰坦震」。

All told, Dragonfly will spend about three years exploring Titan,

蜻蜓號團隊在北美 和世界各地有數百人，

measuring its detailed chemistry,

他們正在努力設計這次任務，

observing the atmosphere and how it interacts with the surface,

開發旋翼飛行器、 自主導航系統及各種儀器，

and even listening for earthquakes,

這些東西都需要互相配合， 以達成在泰坦表面進行科學測量的任務。

or technically titanquakes, in Titan's crust.

蜻蜓號是我們探索這個 迷人的自然實驗室的下一步。

The Dragonfly team,

航海家在飛過時，暗示了各種可能性。

hundreds of people across North America and around the world,

卡西尼環繞土星運行十多年

is hard at work on the design for this mission,

和惠更斯穿過泰坦大氣層後，

developing the rotorcraft, its autonomous navigation system

泰坦的面紗又多拉開了一點。

and its instrumentation,

蜻蜓號將生活在泰坦環境中。

all of which will need to work together to make science measurements

到目前為止，我們唯一的泰坦特寫照片

on the surface of Titan.

是惠更斯探測器在 2005 年 1 月拍的。

Dragonfly is the next step in our exploration

在許多方面，泰坦是我們已知星體中

of this fascinating natural laboratory.

和早期還沒有生物的地球 最相似的一個。

In flying by, Voyager hinted at the possibilities.

從卡西尼－惠更斯的測量中，

In orbiting Saturn for over a decade

我們知道生命組成成分

and descending through Titan's atmosphere,

——至少是我們知道的 生命組成成分——

Cassini and Huygens pulled Titan's veil back a bit further.

已經存在於泰坦上，

Dragonfly will live in the Titan environment,

而蜻蜓號將完全沉浸在 這個外星環境中，

where, so far, our only close-up view

尋找類似於那些可能支持 地球上生命發展的化合物，

is this image the Huygens probe took in January 2005.

並讓我們瞭解其他世界的適居性。

In many ways, Titan is the closest known analogue we have to the early Earth,

適居性是個吸引人的概念。

the Earth before life developed here.

是什麼使一個環境適合孕育生命？

From Cassini-Huygens' measurements,

無論是我們已知的地球生命，

we know that the ingredients for life,

或是在非常不同的條件下 發展出的異星生命。

at least life as we know it,

外星生命存在的可能性

have existed on Titan,

在歷史上激發了人類的想像力和探索。

and Dragonfly will be fully immersed within this alien environment,

放大規模來看，

looking for compounds similar to those

這就是外太陽系的海洋世界

that might have supported the development of life here on Earth

成為如此重要的研究標的的原因。

and teaching us about the habitability of other worlds.

「如果」推動著人類的探索。

Habitability is a fascinating concept.

我們不知道化學物質 如何在地球上演變成生物，

What's necessary to make an environment suitable to host life,

但類似的化學過程 可能曾發生在泰坦上，

whether life as we know it here on Earth,

因為那裡的有機分子 有機會與液態水混合。

or perhaps exotic life that has developed under very different conditions?

有機合成反應在這些條件下有進展嗎？

The possibility of life elsewhere

如果是，到了甚麼程度？

has inspired human imagination and exploration throughout history.

我們……

On a grand scale,

還不知道。

it's why the ocean worlds in the outer solar system

未來我們從蜻蜓號學到的東西， 這種人類根本的努力，

have become such important targets for study.

是很誘人的。

It's the "what if" that drives human exploration.

它在尋找的是地球 在演變出生命的過程中，

We don't know how chemistry took the step to biology here on Earth,

一步一步累積的一磚一瓦、 地基和化學反應。

but similar chemical processes may have happened on Titan,

我們不確定到達泰坦時， 我們會找到什麼，

where organic molecules have had the opportunity

但這正是我們要去的原因。

to mix with liquid water at the surface.

1994 年，卡爾·薩根寫道：

Has organic synthesis progressed under these conditions?

「在泰坦上，過去 40 億年來

And if so, how far?

像神賜嗎哪一樣 從天而降的分子可能還在那裡，

We don't know ... yet.

沒什麼改變，

What we will learn from Dragonfly, this fundamentally human endeavor,

深凍著，等待來自地球的化學家。

is tantalizing.

我們就是那些化學家。

It's a search for building blocks, foundations, chemical steps

蜻蜓號的任務不僅是幫我們 了解泰坦和我們太陽系的奧秘，

like those that ultimately led to life on Earth.

更是要尋找我們自己的起源。

We're not sure exactly what we will find when we get to Titan,

謝謝。

but that's exactly why we're going.

In 1994, Carl Sagan wrote,

"On Titan, the molecules that have been raining down

like manna from heaven for the last four billion years

might still be there,

largely unaltered, deep-frozen, awaiting the chemists from Earth."

We are those chemists.

Dragonfly is a search for greater understanding,

not just of Titan and the mysteries of our solar system,

but of our own origins.

Thank you.