宇宙（2007）

pieces of Mars here on Earth.
在地球上研究火星碎片
In 2010, NASA announces
2010年 美国宇航局宣布
that more advanced electron microscopy of ALH 84001
对阿兰山84001的最新电子显微镜分♥析♥
reveals new details of iron oxide crystals,
发现了新的氧化铁晶体
called magnetite,
叫做磁铁矿
a mineral within its own magnetic field
一种来自身具有磁场的矿石
that on Earth can be created by certain ocean-dwelling bacteria.
其在地球上可由某种海洋细菌产生的
Bacteria here on Earth have figured out
这种地球细菌能够
how to grow magnetite crystals in their own bodies
在体内产生磁铁矿晶体
that help them to orient to the Earth's magnetic field
帮助它们适应地球磁场
in order to help them swim in the ocean
使它们能在海里游泳
and orient while feeding.
在进食时进行定向
Are the crystals in ALH 84001
阿兰山84001中
fossilized magnetite created by martian bacteria
石化的磁铁矿晶体是由火星细菌产生
to help them hunt and feed in an ancient ocean
就在40亿年之前
when Mars still had its magnetic field
火星仍存在磁场时
more than 4 billion years ago?
借此在古老的海洋觅食的吗
If they are fossils
如果它们是化石
of course they indicate early Mars
就能说明早期火星
had faily sophisticated life.
拥有极复杂的生命体
That's still being batted about
这个问题还在推敲
and bottom line is there's still a heck of a lot of
结果是仍然有许多
scientific work being done
科学工作要做
and a lot of debate about Mars' meteorites,
许多对火星陨石的争论
whether there's any evidence past life in those.
到底有没有任何生命存在过
But the latest and most compelling evidence of Martian life
但是最近的 最引人注目的证据
isn't in an ancient meteorite,
不在于古老的陨石中
but on Mars today,
而是存于现在的火星上
even though this new evidence is invisible.
尽管这个新证据还未显现
For years, scientists looking for life on Mars
多年来 科学家们在火星上寻找生命
have followed the water,
一直追寻着水
but there may be something to follow,
但是接下来还有点
that's even more dramatic.
更令人激动的事情
Between 1999 and 2009,
1999到2009年间
spectrographic observations of Mars
对火星的光谱观测
detect a combination of carbon and hydrogen
探测到了一种碳氢结合物
called methane gas.
叫做甲烷气
The discovery of methane on Mars, in Mars' atmosphere,
在火星大气层中发现甲烷
was a real surprise to people.
实在令人吃惊
Plumes of the gas seem to be coming
气体烟雾似乎是在夏季
from a few "Hot spots" during the Martian summer.
从火星的几个热点冒出来
The trouble is there shouldn't t be any methane on Mars.
令人费解的是火星上本不该存在甲烷
On Mars, even just the presence of methane,,
在火星上 即便是甲烷的出现
is a little bit mysterious because it breaks down.
都有些神秘 因为它会分解
On Earth, the unstable methane molecule
地球上 不稳定的甲烷分子
disintegrates after about 300 years.
经过约300年就会分解
But on Mars, high doses of ultraviolet radiation
而在火星上 受到大量的紫外线辐射
and perhaps the newly discovered dry lightning
以及新近发现的干闪电的影响
in the thin, dusty Martian atmosphere
在火星稀薄而尘霾的大气内
break the methane down in just a few months.
或许只需数月就能让甲烷完全解体
And so if you see it there,
因此 如果甲烷存在的话
it means there must be something resupplying it.
意味着一定也存在某种供源
Even though it's being broken down,
因此即使它不断分解
it's getting resupplied.
也还有源源不断的供给
Where's the Martian methane coming from?
火星甲烷究竟来自何方
On Earth, volcanoes produce vast amounts of methane.
地球上 火山活动产生大量的甲烷
But even though Mars has Olympus Mons,
然而即使火星上有奥林帕斯山
the largest volcano in the solar system,
这座太阳系内最大型的火山
it hasn't t erupted for millions of years.
也有数百万年不曾喷发了
So what are the other choices?
还有其它选项吗
Methane can be produced underground
甲烷也可以来自地下
when basaltic rock gets turned into a mineral called serpentine.
当玄武岩转化为蛇纹岩
and that releases methane
会释放甲烷
And that methane can seep up through the ground,
甲烷慢慢渗出地表
and come out in the atmosphere.
进入大气
But this process requires hot liquid water
然而该过程需要高温液态水的存在
which hasn't yet been found on or within Mars.
这在火星表面及内部尚未发现
Could be volcanoes which we don't
在火星上是否有我们至今未知的
know to be active on Mars, so that would be interesting.
活火山存在呢 这就很有趣
It could be some subsurface chemistry with liquid water,
也可能是火星地下我们未知的
which we don't t know to be on Mars,
某种含液态水的化学物质
so it'd be interesting.
这也很有意思
Or it could be due to biology.
还可能就是源于微生物
On Earth, 90% of methane
地球上 90%的甲烷
comes from bacteria in animals and plants.
源于动植物体内的细菌
Is the Martian methane coming from
那么火星的甲烷是否
underground colonies of bacteria?
就来自地底的细菌菌落呢
The discovery of methane on Mars led to headlines
火星上有甲烷的消息登上报纸头条
of us having definitively found evidence for life on Mars.
成为发现火星生命存在的决定性证据
And entire chat rooms were set up
人们建了许多聊天室
to discuss these various creatures, but in fact,
讨论各种火星生物 然而事实上
though the discovery of methane is interesting,
尽管甲烷的发现非常有趣
it doesn't mean that
但这并不意味着
we found creatures wandering around on Mars.
我们在火星上发现了四处游荡的生物
Maybe it is life.
或许的确存在生命体
It's an arrow to something and
我们对未知只有一步之遥
maybe the thing at the end of the arrow is life.
或许一步之遥外的未知就是生命
The search for the source of Martian methane
探查火星甲烷来源
has become a priority for explorers
成为探索者们的当务之急
and is on the mission list for the next rover to be sent to Mars.
也是即将发射的火星登陆探测器任务之一
So we're looking at a so-called test bed version,,
现在我们看到的是所谓的测试床版的
of the Mars science laboratory rover.
火星科学实验室探测器
And the Mars science laboratory,
当火星科学实验室
when it gets down to the surface, will measure methane.
在地表着陆后 会检测甲烷
So we'll know the answer once that rover gets down there.
探测器到达后一切都会真♥相♥大白
The Mars science laboratory dubbed "Curiosity"
被称为"好奇者"的火星科学实验室
will launch in the fall of 2011, and land in 2012.
将于2011年秋发射 2012年着陆
It's the size of a small car
它的身形如小型汽车
and will use an amazing new landing technique,
会以一种不可思议的新技术进行着陆
the sky crane.
称为空中起重机
At about 60 feet above the ground,
在离地面60英尺时
the rover is separated from the descent stage
探测器与着陆架分离
and lowered on a line, which we call the bridle,
由缰索束缚直线下降
and slowly lowered to the ground anand lowered to the ground.
并缓慢地降至地面
When the rover's wheels touch down on the ground,
当探测器四轮着地
the descent stage detects that.
着陆架收到反馈信息
It cuts those lines and then it flies away
它将缆索切断并飞向远方
and it crashes safely far away
在安全距离之外坠毁
and the rover is on the ground, on its wheels,
探测器就四平八稳到达地表
ready to go do its job.
随时准备开展工作
The high-frequency radar, essential to ththe sky crane landing,
高频雷达是空中起重机式着陆的关键
is mounted to a helicopter and taken for a test-drive
现正安装在直升机上进行实际测试
at California's Edwards air force base.
地点就在加州爱德华兹空军基地
When you're coming down on Mars,
说到火星着陆时
we don't watch a simulation and analysis
对于下降角度
to go ahead and give us bounds of what we expect to see
及降落伞的姿态角速度等
in terms of descent angles,
我们无法通过模拟和分♥析♥
in terms of attitude rates on the parachute.
得出我们期待的边界范围
During the entry, descent, and landing,
在进入 下降和着陆的过程中
the radar tells us where the ground is
雷达会反馈地面位置
and how fast we're going.
以及飞行器行进的速度
That information is used by the control system
控制系统用这些信息
to control the thrusters to make sure we touch down at a nice gentle speed.
确保推进器着陆时能稳稳当当
We test little pieces here and little pieces there,
我们将各个部分进行了仔细测试
so the first time that we test it for real is on Mars.
而首次真正的考验就在火星
The key objective of the Mars science laboratory
火星实验室的首要目标
is to search for signs of ancient habitats.
是搜寻远古生物栖息地存在的迹象
And so the rover will rove up to areas that had
探测器会不断地来回勘查
been soaked in water in the past,
一度水盈土润的那些区域
and it may have trapped organics.
以期找到残存的有机物