了解宇宙是如何运行的（2010）

It's a soup of methane and ethane and propane
和乙炔的浓汤
And acetylene.
里头的有机分子
Uh, the list of organic molecules is literally
我们侦测到有数百种
Hundreds, hundreds long that we've detected there.
土卫六的大气层
Titan's complex cocktail
混合了复杂的化学成分 让科学家的充满好奇
Of atmospheric chemicals intrigue scientists.
但也让他们困惑
But it also puzzles them,
尤其是气态甲烷 在阳光下会快速衰变
Especially methane gas, which rapidly decays in sunlight.
所以即使土卫六离太阳如此远
So even a billion miles from the sun,
它浓密的大气层应该早就消失
Titan's thick haze should've lifted long ago.
一定有庞大的甲烷来源在补充
A vast source of methane must be replenishing
它的橙色大气
The orange smog.
在卡西尼号♥任务之前
Before cassini,
科学家推测
Scientists assumed the whole of titan
土卫六表面布满了巨大的撞击圆坑
Was covered in massive impact craters.
也许这些火山湖充满了液态甲烷
Perhaps crater lakes filled with liquid methane
而甲烷会蒸发到大气层中
Were evaporating into the atmosphere,
补充消失的气体
Supplying the missing gas.
为了解开谜团
To help prove this theory,
卡西尼号♥带着惠更斯探测器一路飞到土星
Cassini carried a hitchhiker all the way to saturn.
惠更斯登录器打开降落伞
The huygens lander released high above titan's equator
穿过云端 一边降落一边拍摄照片
Parachuted through the clouds, snapping photographs as it fell.
它通过大气层时
As it went through the atmosphere,
搜集了大量的数据
It took a huge amount of data
接着它落到土卫六地表 开始拍照
And then landed on the moon itself and took pictures.
我们头一次看照片时
When we first saw those pictures,
就像看着改变人生经验的东西一样
It was life-Changing.
地表没有坑洞
There were no craters.
那里似乎曾经有流动的液体形成了现在的地貌
It looked like flowing liquid had once shaped the landscape,
但是惠更斯号♥的降落地点 放眼所及之处
But at the landing site and as far as huygens could see,
那些液体早就消失了
That liquid was long gone.
惠更斯当年降落的地点
Huygens landed in a spot almost identical
和这里几乎一模一样
To what we're standing on right now.
你看四周
If we look all around,
都是一片荒凉贫瘠
We can see this bleak, barren landscape.
地上有大小不一的卵石
We see pebbles and cobbles
磨得很圆滑
That have been rounded and smoothed
因为他们来自河道
Because they've come through river channels.
惠更斯号♥降落的地点有很多这种石子
We see plenty of those at the huygens landing site.
此外 还有很多沙
Uh, in addition to that, we see lots of sand.
惠更斯号♥降落的沙漠极其辽阔
The desert huygens landed in is huge.
它沿着土卫六的赤道一路延伸
It stretches all the way around titan's equator...
还有高达300英尺（约91米）被风吹成的沙丘
with 300-Foot tall dunes sculpted by the wind
就跟地球上的沙丘一样
Just as they are on earth.
如果巨大的火口湖不在赤道
If the vast crater lakes weren't at the equator,
就一定在土卫六的南北极
They had to be at titan's poles.
因此卡西尼号♥又计划多次
Cassini scheduled a number of additional flybys
执行寻找液体迹象的飞行任务
To look for any signs of liquid.
卡西尼号♥有雷达枪设备
One of the instruments onboard cassini is basically a radar gun.
他会对土卫六发射雷达波并接收返回的雷达波
It shoots radar waves at titan, and they get reflected back.
经过两年的搜索
After two years of hunting with this instrument,
科学家终于得到了他们期待已久的信♥号♥♥
Scientists finally got the signal they were waiting for.
卡西尼号♥发现
One of the things it found
在土卫六的北极附近
Is that near the north pole of titan
有些区域不会反射雷达波
Were regions that were not reflecting radar,
看样子很有可能是液体
And that sounds a lot like liquid.
液体会吸收能量 所以不会反射
Liquid absorbs that energy and doesn't reflect it back.
之后的观察证实了这个想法
Later observations clinched it.
卡西尼号♥终于拍到土卫六北极的影像
When cassini finally imaged the north polar regions of titan,
里头有我们期盼已久的
It it finally saw these lakes and seas of methane
甲烷湖泊和海洋
That we'd been looking for,
令人意外的是甲烷并不在撞击圆坑里
Only they weren't contained in impact craters like we thought.
而是在大型湖泊盆地里
Instead they're contained in big lake basins
跟地球的非常相似
That look just like they do on earth.
这个大型洼地湖位于加州莫诺郡
Basin lakes like this one in mono county, california,
洼地湖是构造活动产生的洼地形成的
Form in the depressions leftover from tectonic activity.
土卫六的这些地质特征
These geological features on titan
只能表示一个惊人的事实
Could only mean one shocking thing
这个卫星是活的 它有地质活动
The moon was alive with geological activity.
要是我们在土卫六最大的海
If we were sitting on the margins of kraken mare,
海怪海的边缘
Which is the largest sea that we see on titan,
我们应该会看到跟这里很相似的地貌
Then we would probably see something very similar to this landscape.
我们会看到相当平静的海面
We would look out across a fairly calm surface,
土卫六的风应该不强
We think the winds are not very strong on titan.
所以我们会看到平静的甲烷和乙炔湖
And so we'd have this calm lake of methane and ethane.
而远方会有山丘和山脉
And in the distance we would see hills and mountains
它们很可能是构造运动形成的
That have formed on titan probably through tectonic processes
就跟地球山脉形成的方式一样
In much the same way that mountains are built on earth.
只不过土卫六非常冷
Except on titan, it's so cold,
所以火山喷的是水 不是熔岩
The volcanoes spew water, not lava.
而且山脉和湖的盆地都是固态冰
And the mountains and lake basins are solid ice.
一开始 科学家本来以为
At first, scientists thought that methane evaporating
从这些湖泊蒸发的甲烷 形成了土卫六的大气
From these lakes generated titan's smog.
但卡西尼号♥再度测量这些湖泊时
But when cassini flew by to measure the lakes again,
湖泊平面似乎还是一样
The levels appear to be the same.
这些湖泊似乎完全没有蒸发
The lakes didn't look like they were evaporating at all.
科学家被难倒了
Scientists were stumped.
要不就是大气中的甲烷
Either the lakes weren't the source
不是来自湖泊
Of atmospheric methane
或者就是甲烷会重新填满湖泊
Or they were somehow being refilled.
珍妮瑞德鲍 行星地质学家
Planetary geologist, jani radebaugh,
她认为不明甲烷的关键线索
Believes a crucial clue to the missing methane
就在岩石沉积物石灰华里面
Lies in the formation of rocky deposits called tufa.
莫诺湖这里有石灰华
They're found here at mono lake,
从地面涌出的干净泉水
Where clean spring water rises up from the ground
流进富含矿物质的湖水中 两者产生化学作用 形成石灰华
Into the mineral-Rich lake where the two water types react.
我很兴奋 这可能是土卫六
This is very exciting because this could be a clue
不明甲烷的线索
To the missing methane on titan.
这种岩石是由两种液体的
So it's rock that has been formed from the chemicals
化学成分形成的
Contained in two fluids.
泉水从湖边涌出来
There is water that's emerging at the margin of the lake.
和湖水发生相互作用
It's interacting with the lake water
两者的化学成分不一样
Which has a very different chemistry
熔在水里的化学物质混在一起
And all of the chemicals that are dissolved
就形成了这种石头
Combine with each other and create this rock.
根据雷达影像
Radar images of titan's largest lake
土卫六最大的湖泊边缘有岩石构造
Reveal rocky structures around the margins
看起来就像莫诺湖的石灰华
That look just like mono lake's tufa.
无论这个构造是不是土卫六石灰华
Titan's tufa, if that's what they are,
它或许可以证明土卫六的
Could be evidence of a layer of liquid methane
冰冻核心外♥围♥有一层液态甲烷
That sits above titan's frozen core
液态甲烷会涌进湖里
And rises and springs to feed its lakes
就像这里的泉水会涌进莫诺湖
Just like spring water rises to feed mono lake.
甲烷泉水涌进湖泊
So when those methane springs come in,
和湖泊发生相互作用
They interact with the lakes and a rock precipitates out.
就会沉淀成岩石
So we see these organic rocks
我们发现有机岩石
Dotting the margins of the lakes.
散布在这些湖泊的边缘
And almost certainly there's also methane
几乎可以确定湖边
Just bubbling up and emerging
有液态甲烷涌上来
At the margins of the lake as well.
如果珍妮说得对
If jani is right,
土卫六的湖泊确实会蒸发 补充大气层
Titan's lakes do evaporate, feeding the atmospheric smog,
而地底的甲烷泉会源源不断地
But they're constantly replenished
补充湖泊失去的液体
By underground methane springs replacing the lost fluid.
土卫六不是死亡世界
Titan is no dead world.
它有活跃的地质运动及复杂的化学作用
It's alive with active geology and complex chemistry.
它可能还有其他的现象
And it might be alive with something else
而这种现象非常巨大
Something really big.
以前我们认为土星离太阳很远
We used to think that saturn was too far
温度太低 不可能有剧烈现象
From the sun and too cold to play host to anything dramatic.
现在我们发现错得离谱