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Who doesn't love the Moon? Without it, we wouldn't have romantic moonlit strolls, or the ebb and flow of the tides.
有人会不喜欢月亮吗？如果没了月亮，我们不会欣赏到浪漫的月下漫步，也不会欣赏到潮涨潮落。
Worst of all, there wouldn't be werewolf stories.
最糟糕的是，也不会有跟狼人有关的故事了。
But even though it's our closest neighbor, there's still a lot we don't know about the Moon.
但即便月亮离我们最近，但我们对月亮的探索还有很长的路要走。
So let's talk about three of the most intriguing Moon mysteries:
那么本期，我们就来探讨一下月亮最让人着迷的几个未解之谜：
its past magnetic field, the lunar sunrise, and what could be hidden inside its craters.
它以前的磁场是怎样的、月球上的日出、月球火山口内部隐藏着什么。
Now, Earth's magnetic field is kind of a big deal.
如今，地球的磁场问题是很让我们纳闷儿的问题。
It helps us navigate, and it deflects the Sun's solar wind.
正是因为地球上有了磁场，我们才能导航，才能让太阳风发生偏斜。
Without it, we'd be hit with charged particles, skin cancer would skyrocket, and the ozone layer would be toast.
如果地球上没有磁场，我们就会受到带电粒子的撞击，人人都会得皮肤癌，臭氧层就会焦灼。
See, the Earth's outer core is a molten, metallic fluid that contains electric charges.
由此可以得出，地球的外核是融化的金属流体，带有电荷。
Those charges circulate around, and create a magnetic field.
这些电荷会循环往复地运动，形成了磁场。
Scientists call this the dynamo effect. For the longest time, we thought the Moon couldn't have had a magnetic field.
科学家将这种现象称之为发电机效应。很长时间以来，我们一直以为月球是没有磁场的。
But then, Apollo astronauts brought home a bunch of Moon rocks, and lots of them were magnetic.
直到阿波罗号的宇航员带来了一些月球岩石的样本，很多样本都是带有磁性的。
After analyzing these rocks and doing some computer simulations, we now think that the Moon has a molten outer core, and used to have its own magnetic field … 4 billion years ago.
在分析了这些岩石之后，我们做了一些计算机模拟，于是我们现在认为，月球的外核是熔融的，而且以前也是有自己的磁场的……所谓“以前”是指40亿年前。
What's more, it seems like the Moon's magnetic field could've been even stronger than the Earth's, and stuck around for way longer than we thought possible – around a billion years.
此外，月球的磁场可能比地球的磁场还要强，其存在的时间比我们想象的也要长很多——大概10亿年左右。
How? Well, that's the big mystery, but scientists have a few ideas.
为什么会这样呢？这是个很大的谜题了，不过科学家还是有一些思路的。
The Moon used to be closer to the Earth than it is now, so maybe the Moon wobbled, or precessed, so much back in its early days that its molten fluids started circulating.
月球以前与地球的距离比现在更近，所以月球的轨道可能忽远忽近，岁差就会产生变化，所以熔融液体就会开始循环。
Or maybe the Moon was pelted with so many asteroids, it forced the fluids to slosh around.
也有可能是有很多小行星撞击了月球，迫使液体产生波动。
But one of the most promising ideas has to do with the internal layers of the Moon blending:
但最有可能的推断与月球内层的融合有关：
Thanks to the pull of Earth's gravity, the Moon's core and mantle might have rotated on different axes.
由于地球引力的作用，月球内核和地幔可能就在不同的轴线上发生旋转。
If these layers weren't perfectly spherical, the molten fluids would have mixed around.
如果内核和地幔不是完美的球形，这些熔融的液体就会发生混合。
As the Earth and Moon moved apart, the gravitational pull weakened, and the angle between the axes of rotation would have decreased.
随着地球和月球的逐渐分开，引力的作用就会减弱，旋转轴之间的角度就会减小。
No circulating fluids means no magnetic field.
如果没有循环液体，就意味着没有磁场。
But these are still just hypotheses, and we'll need more modeling, especially from scientists who specialize in magnetic dynamos, to see how likely they are.
但这些还都只是假设，我们需要做更多的建模，尤其需要擅长磁场发电机效应的科学家去做建模，以验证这些说法的可能性有多大。
Magnetism isn't the only mystery uncovered by Apollo astronauts: When they visited the Moon, they saw a glow before the Sun rose over the lunar horizon.
磁学并非阿波罗号宇航员发现的唯一谜题：他们到访月球的时候，还发现太阳在升到月球地平线之前会出现辉光。
The beauty of a sunrise might seem normal to us on Earth, but the Moon has an incredibly thin atmosphere, which means fewer gases to scatter light.
地球上出现日出之前会产生这样的景象对我们来说可能习以为常。但月球的大气层十分轻薄，所以就没什么气体能让光产生散射。
These astronauts saw a lunar sunrise with three parts: A low glow on the horizon, a glow that arced higher, and rays of light.
这些宇航员看到3个部分的月球日出光：一部分在地平线上，位置较低；一部分是弧形的，位置更高些；还有一部分是光线。
Researchers think the low horizon glow is dust being lit up, like when light shines into your bedroom and you see how badly you need to vacuum.
科学家认为较低的那部分是灰尘被照亮后产生的现象，就像阳光照进卧室里，你会觉得十分需要真空环境。
The arcing glow is probably coronal and zodiacal light, sunlight scattering off comet and asteroid dust in the inner solar system.
弧形的光晕很可能是黄道带发出的冠状光，是太阳系内部彗星和小行星灰尘散射出的日光。
Sometimes, we see it on Earth, too. But those rays... we don't know.
有时候，这种光在地球上也看得到。但月球上的这些，我们不太清楚。
Our best guess is that the Sun's radiation could be ionizing Moon dust, and the charged dust particles might be repelling each other into the lunar sky.
最有可能的猜想是：太阳的辐射可能使月球上的灰尘产生电离，而发生电离的灰尘颗粒可能会由于彼此的相斥作用而在月球的天空中得以展现。
When sunlight hits those dust streams – hello rays.
日光射到灰尘流的时候，就会产生打招呼一样的光线。
Understanding the rays could possibly be important for future Moon colonies, because charged dust wouldn't exactly be friendly to lots of electronic equipment.
了解这些光线很可能对未来人类在月球生活有重要意义，因为带电灰尘对很多电子设备都不是很友好。
NASA wanted to solve this mystery with the LADEE mission in 2013 and 2014.
美国宇航局希望能通过2013年和2014年的月球大气与粉尘环境探测器来解决这个谜题。
But the spacecraft didn't find evidence of mysterious rays or dust fountains.
但月球大气与粉尘环境探测器并未发现神秘光线或灰尘流存在的证据。
So for now, all we can do is guess.
所以现在，我们只能做猜测。
Our third mystery isn't in the sky, but hidden deep inside the Moon's craters.
第三个谜题与天空无关，而与月球火山口深处隐藏的东西有关。
Craters are sheltered and cooler than the surface, so there's a lot we could find, like water ice, different kinds of rocks, or even possibly signs of past life.
火山口得到掩盖，所以温度比地表更低，所以我们能发现很多信息，比如固态水、不同种类的岩石、甚至过去存在生命的迹象。
See, the early solar system was downright violent.
通过这些，我们可以感受到初期的太阳系运动十分猛烈。
Around 4 billion years ago, when the Earth and Moon were young and being pelted with asteroids, they would've swapped a lot of rock.
大概40亿年前，地球和月球还都很年轻，会受到很多小行星的撞击，所以收获了很多岩石。
This might've been when life was first forming on Earth.
可能正是从那时候开始，地球上逐渐有了生命。
It wasn't very flashy life – we're talking single-celled prokaryotes.
不过不是那种很复杂的生命形态——那时候出现的是单细胞原核生物。
What they lacked in looks, they made up for in toughness.
虽然形态并不好看，但生命力十分旺盛。
Earth had lots of volcanic activity and an atmosphere that would be toxic to most life today.
地球上的火山活动很多，大气层对于今天的大多数生命来说都是有毒的。
Most scientists consider this a long shot, but if any of these microbes ended up on a chunk of Earth that crashed into the Moon, they might have been buried in a crater.
大多数科学家认为这种情况不太可能发生，但如果这些微生物最后落脚在地球上的某个区域，而这个区域又撞落在月球上，这些微生物就会被掩埋在火山口以下。
All the rocks on Earth this old have been destroyed or reshaped, so we don't have any records of this period on our planet.
地球上的所有岩石，但凡有这么大岁数的，不是遭到了毁坏，就是变形了，所以我们没有这个时期地球上的任何记录。
The Moon's craters, though, could give us a glimpse of that period of our history, and even let astrobiologists know where they might find life on other planets and moons.
不过，月球上的火山口可以让我们对那个时期地球的历史有所了解，天体生物学家甚至可以知道他们在其他行星或者卫星的哪里可能会发现生命。
We won't know for sure until we go digging for samples, whether with robots or a good old fashioned shovels. Any volunteers?
搜寻样本后，我们才会确定。搜寻样本的方式并不单一，可以用机器人，也可以老式铁铲。有愿意当志愿者的吗？
So, our solar system is full of interesting things to explore, and everyone's really hyped about getting to Mars right now.
我们的太阳系里有很多有趣的事情有待探索，每个人都迫不及待地想要去火星。
But since we still don't understand everything about the Moon, maybe we should take a look closer to home.
但由于我们对月球并非了如指掌，所以我们或许应该在离地球更近的地方先试试水。
Thanks for watching this episode of SciShow Space, and especially to our patrons on Patreon.
感谢收看本期的《太空科学秀》，尤其要感谢我们的忠实粉丝。
Right now, we are doing something a little bit different on Patreon.
现在，我们为忠实粉丝带来了一些与众不同的福利。
Until the end of the year ,we are going to be taking all of the money that we raise on Patreon and putting it toward a new show.
今年年底之前，我们将会将募集到的所有资金用于创办一个新节目。
The three choices for the new channel are SciShow Life, SciShow Psych, and SciShow Health.
新节目将在3个选项中诞生，有：太空生活秀、太空心理秀、太空健康秀。
If you're interested in any of those ideas, Patreon patrons are going to be deciding which of these is going to be comes its own channel.
如果您对这几个选项感兴趣，可以决定哪个选项可以胜出。
Of course, if you're not interested in any of that, thank you for watching all the same, and don't forget to go to youtube.com/scishowspace and subscribe!
当然了，如果您对任何一个选项都不感兴趣，那也依然感谢您对我们节目的支持。不要忘记订阅youtube.com/scishowspace哦！
