了解宇宙是如何运行的（2010）

How the Universe Works S11E02

Part 7 April 10, 2023, 10:20 a.m.

the ice begins to melt.
实际上，盐水的结冰温度
Saltwater actually freezes at
比淡水低得多
a much lower temperature
than water that's fresh.
所以如果是盐水
So if it's salty water,
它实际上可以在较低的温度下保持液态
it could actually stay liquid
at lower temperatures.
我们仍然不能百分之百地确定
ROWE: We still aren't
100 percent sure that the lakes
这些湖是完全液态的
are completely liquid.
一些科学家认为它们可能是冻结的粘土湖
Some scientists think they
could be lakes of frozen clay.
在我们有了能在两极之下探索的漫游者之前
Until we have a rover that can
explore beneath the poles,
我们还无法确定
we won't know for sure.
我们还无法确定
we won't know for sure.
我们唯一能确定的方法
The only real way we can tell
for sure is to send
是发射某种探测器
some kind of mission
that drills
直接钻穿极地冰层，并在底部
right down through
that polar ice and samples
对我们发现的东西进行采样
what we find at the bottom.
不管火星的水藏在哪里
ROWE: Wherever it may
be hiding,
它都被锁住了
Mars's water is locked away,
但在过去，火星上有令人印象深刻的湖泊和河流
but in its past, the planet had
impressive lakes and rivers.
它们曾经孕育过生命吗？
Did they ever host life?
为了找到答案
To find out, the rovers
探测车深入火星
take a deep dive into Mars.
探测车深入火星
take a deep dive into Mars.
资深探险家“好奇号♥”探索着盖尔陨石坑
Veteran crew member, Curiosity,
explores the Gale Crater.
探测器的任务是什么？寻找火星上
The rover's mission?
To find evidence
是否曾有生命存在的证据
of whether Mars could have
supported life.
洛斯阿♥拉♥莫斯国家实验室
Los Alamos National Laboratory.
“好奇号♥”化学摄像头的
Principal investigator
of Curiosity's
首席研究员尼娜·兰扎
ChemCam, Nina Lanza,
works closely with the rover
首席研究员尼娜·兰扎
ChemCam, Nina Lanza,
works closely with the rover
与远在3400万英里外火星上巡逻的火星车密切合作
patrolling Mars 34 million
miles away.
在很多方面，好奇号♥就像我的第一个孩子
In many ways, Curiosity
is like my first child.
当她还在地球上的时候，我们必须好好照顾她
We had to take such good care
of her while she was still here
但像所有的孩子一样，她必须开辟自己的道路
on Earth, but like all children,
she had to forge her own path.
所以我们不得不送她去火星上
And so we had to send her
on her way
独自探索新事物
to discover new things
on Mars by herself.
化学摄像头使用精密激光
ROWE: ChemCam uses
a precision laser that
分♥析♥火星岩石的化学成分
analyzes the chemical
composition of Martian rocks.
分♥析♥火星岩石的化学成分
analyzes the chemical
composition of Martian rocks.
兰扎:我们有一个激光聚焦到23英尺外的目标上
LANZA: We have a laser that
we focus onto a target
我们蒸发一些物质
up to 23 feet away, and we
vaporize a little material,
然后我们观察这种蒸发物质
and then we look
at the light
发出的光，然后找出
made by this vaporized material
and figure out
岩石中有什么元素
what elements are in the rock.
使用像化学摄像头这样的仪器工作
Working with an instrument
like ChemCam is really
真的是儿时的梦想成真，因为我一直希望
a childhood dream come true,
because I was always hoping
在宇宙飞船上工作，而今天，我在一艘
to work on a spaceship,
and today, I work on
使用激光的宇宙飞船上工作
a spaceship with lasers.
这是多么酷的事？
How cool is that?
在长距离的合作下
ROWE: With their
long-distance teamwork, Nina
妮娜和好奇号♥发现了
and Curiosity discover rocks
with a shiny coating,
表面镀有闪亮锰的岩石
laced with manganese.
兰扎:好奇号♥在盖尔陨石坑最令人兴奋的发现之一是
LANZA: One of the most exciting
discoveries from Curiosity in
高浓度锰元素的存在
Gale Crater was the existence
of high concentrations
这是因为地球上的
of an element called manganese,
and that's because manganese on
锰与生命密切相关
Earth is very closely tied
to life.
火星上的锰与生命形式有关吗？
Could the manganese of Mars
be linked to life forms?
为了调查，科学家们观察了地球上沙漠岩石上
To investigate, scientists
look at similar coatings
为了调查，科学家们观察了地球上沙漠岩石上
To investigate, scientists
look at similar coatings
类似的涂层，称为清漆
called varnish on desert rocks
here on Earth.
我这里有一个岩石清漆的样本
So I have an example here
of some rock varnish,
你可以看到，它实际上非常黑
and you can see,
it's actually incredibly dark.
它含有大量的氧化铁
It has a lot of iron oxide,
氧化锰和粘土矿物
manganese oxide,
and clay minerals in them.
有时岩石本身
And the rocks
can sometimes have
没有这些物质
none of these things
in the rock itself.
所以问题是，这种涂层是从哪里来的？
So the question is, where does
this coating come from?
拉德博:通常，我们会发现
RADEBAUGH: Often,
we find microbes associated
与清漆有关的微生物
with the varnishes
and so possibly,
所以可能这些微生物
these microbes
actually helped fix
实际上帮助锰
these microbes
actually helped fix
固定在表面
the manganese
onto the surface.
这些地球清漆的年龄
ROWE: The age of these Earth
varnishes may provide
可能为火星遥远的过去提供了线索——在这里
a clue to Mars's
distant past -- here,
它们只出现在我们历史上的一个
they only appear after
a significant event in
重大事件之后——
our history --
我们呼吸的氧气的产生
the creation of
the oxygen we breathe.
几十亿年前
A couple of billion years ago
地球上发生了一次大氧化事件
on Earth was the great
oxygenation event.
在这之前，地球的大气中
Basically, the Earth's
atmosphere did not have
没有太多的氧气
a lot of oxygen in it.
没有太多的氧气
a lot of oxygen in it.
它被封存在矿物和化学品中
It was locked up in
minerals and chemicals.
一些细菌发现了如何进行光合作用
Well, some bacteria discovered
how to photosynthesize light,
如何将光中的能量转化为新陈代谢
how to convert energy from
light into their metabolism.
通过这种化学反应，它们释放出氧气
And via the chemistry of this,
they wound up emitting oxygen.
氧气对当时的许多生命形式来说是毒药
ROWE: The oxygen was poison
to many life forms,
所以它们灭绝了
so they died out.
但另一些则蓬勃发展
But others thrived,
pumping more
向大气中注入越来越多的氧气
and more oxygen
into the atmosphere.
氧和锰发生反应
Oxygen reacts with
the manganese,
氧和锰发生反应
Oxygen reacts with
the manganese,
把它束缚在岩石上
binding it to the rocks.
在大气中氧气增加之后
We don't really see
these minerals until
也就是光合作用之后
after the rise of oxygen
in the atmosphere,
我们才真正看到这些矿物质
so after photosynthesis.
火星之所以有这样的锰清漆