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The space telescopes orbiting Earth tend to get a lot of attention.
环绕地球飞行的太空望远镜总是备受瞩目。
It seems like there's always some beautiful new Hubble photo, or a couple of new exoplanets discovered by Kepler.
似乎哈勃望远镜总是能拍到好看的新图片，克卜勒太空望远镜也总是能捕捉到新的外星行星。
But there are some amazingly advanced ground-based telescopes, too, and some of their coolest discoveries have come from ALMA, a telescope that's been observing the universe since 2011.
但也有一些在地球上运作的望远镜十分先进，阿塔卡马大毫米/亚毫米阵列望远镜(ALMA)就是其中之一。自2011年以来，该望远镜就一直进行着观测宇宙的工作。
ALMA, or the Atacama Large Millimeter/submillimeter Array, is made of a set of 66 telescope dishes stretching out over the Chajnantor plateau, part of the Atacama desert in Chile.
ALMA望远镜由66个望远镜碟面组成，跨度超过了智利阿塔卡马沙漠中的查南托高原。
The phrase millimeter/submillimeter describes the chunk of the electromagnetic spectrum that ALMA detects —
毫米/亚毫米表示的是ALMA观测的电磁谱范围——
wavelengths that range from about a millimeter to about 10 millimeters, on the shorter-wavelength end of the microwave spectrum.
即波长，范围从1mm到近10mm不等，在微波谱里波长较短的尾端。
Its huge array of dishes gives ALMA the highest sensitivity of any millimeter/submillimeter telescope in the world.
由于ALMA碟面范围较大，所以该望远镜是世界上灵敏度最高的毫米/亚毫米望远镜。
Since it's the best in its class, ALMA's always being used to observe and re-observe stuff in space.
鉴于它是同类中的最佳望远镜，所以科学家总是用它来观测以及重新观测宇宙里的物质。
And some of the telescope's most amazing finds have taught us about everything from new exoplanets, to ancient star formation, to giant glowing clouds of hydrogen.
该望远镜最近的一些发现成功十分惊人，让我们了解了很多，比如新的外星行星、远古恒星的组成以及庞大的氢气体云。
Like when astronomers used ALMA to clear up the controversy around a star called Fomalhaut.
比如，天文学家曾用它来理清了有关北落师门恒星的疑惑。
Back in 2008, the Hubble Space Telescope discovered what looked like an exoplanet around Fomalhaut.
2008年的时候，哈勃望远镜在北落师门恒星附近发现了一个很像外星行星的物体。
It was the first discovery of its kind.
这是首次发现这种外星行星。
All the exoplanets discovered before that had been found indirectly, through clues like changes in the star's light.
之前我们发现过得所有外星行星都是通过间接方式发现的，比如恒星亮度的变化。
But you could actually see this planet directly.
但这颗行星是可以直接观测到的。
It looked like a denser point of light in the enormous, diffuse disk around the star.
它就像是北落师门恒星附近四散的庞大碟面中的一个密度更高的光点。
But even though astronomers were pretty sure they'd discovered a planet around Fomalhaut, they weren't totally sure.
不过，虽然天文学家十分确信他们在北落师门附近发现了一颗行星，但他们也拿不准。
Because the visible material in the disk, which is mostly small dust particles, does two things:
因为这个碟面中可观测到的、几乎全部由细小的灰尘颗粒组成的物质具备两个特征：
First, it scatters lots of visible light, so if you're observing it in the visible wavelength range, the dust is very bright.
其一，这颗行星四散出许多可见光，所以如果在可见的波长范围里对它进行观测，可以看到灰尘的亮度很高。
And second, the force from solar wind from Fomalhaut can be strong enough to move those dust particles around.
其二，北落师门中太阳风的力度十分强劲，足以将该行星的灰尘颗粒进行移动。
So astronomers knew that the images of the disk taken in visible light didn't necessarily correspond to the actual underlying disk structure.
所以，天文学家就知道在可见光中拍下的碟面图片于实际碟面结构并不一定吻合。
So that planet Hubble found? It might not have been there at all. That's where ALMA came in.
所以哈勃发现的到底是不是行星？还是根本就不存在？这就需要ALMA来一探究竟了。
In 2012, astronomers decided to study the disk around Fomalhaut in millimeter/submillimeter wavelengths,
2012年，天文学家决定通过毫米/亚毫米波长来研究北落师门附近的这个碟面，
which would allow them to see past the haze into the deeper structure, where more massive particles live.
这样就可以投过灰尘颗粒看到更深层的结构，看到质量更大的颗粒在何处。
When they used ALMA to observe the disk, they saw a very sharp and well-defined inner structure, which basically looked like a ring of larger particles.
他们用ALMA观测碟面的时候，发现了一个非常尖利、内部结构十分清楚的物体，看起来就像一个充满了大颗粒的圆环一样。
And based on computer models of the ring, they found that it's probably shaped by a couple of shepherd planets, which orbit on the inside and outside of the ring and sort of corral the particles.
通过这个圆环的计算机模型，他们发现很有可能是牧羊行星体现出了圆环的形状。这些牧羊行星充斥于圆环的内外部，对颗粒排兵布阵。
Which means that thanks to ALMA, we now have a lot more evidence that there really is a planet around Fomalhaut — maybe more than one planet.
所以，我们要感谢ALMA，现在有很多证据可以表明北落师门附近是存在行星的——而且可能不止一颗行星。
So ALMA can see deep into a star's disk. But it can also see deep into the ancient universe.
这样说来，ALMA是可以观测到恒星碟面深处的，而且它还可以观测到远古宇宙的深处。
As the universe expands and sources of light move away from us, the light we see essentially gets stretched out so it has a longer wavelength, in what's called redshift.
随着宇宙的扩张，光源离我们越来越远，所以我们看到的光得到了拉伸，所以其波长更长，这种现象叫红移。
If visible light gets stretched enough, it isn't visible anymore, because it's gone past red and into the infrared, or even microwave range.
可见光若是得到了充分的拉伸，就不再可见了，因为它已经超过了红色的界限，成为了红外乃至微波的范围。
This means that really old, distant things are invisible to our eyes, and to telescopes that can't detect long enough wavelengths.
也就是说，年头越长、离我们越远的物体越不可见，就连望远镜也无能为力，因为望远镜无法观测波长太长的物体。
But we can detect those things if we tune into a lower-energy part of the spectrum.
但如果能转到能量稍低的光谱中，就能进行观测了。
Like, say ... the millimeter/submillimeter range.
比如，毫米/亚毫米的范围。
So, ALMA can see really ancient light!
这样，ALMA就能观测到很久以前的光源了。
Astronomers have been using ALMA in an ongoing project to reobserve Hubble's famous Ultra Deep Field image.
天文学家正在用ALMA来实施一个项目，即重新观测举世闻名的哈勃超深空。
The Ultra Deep Field shows tons of galaxies in a tiny section of sky — the size of a grain of sand held at arm's length.
哈勃超深空可以展现出很小一块天空里的无数星系——将手伸向天空时砂砾大小的区域。
I mean, literally tons. There are about 10,000 galaxies in the image. But we know that there's even more in that section of sky.
是真的有很多星系哦。图中大概就有近1万个星系了。但我们知道这片区域里的星系比我们知道的还要多。
So astronomers are using ALMA to see what Hubble couldn't.
所以，天文学家正通过ALMA来观测哈勃观测不到的物体。
And last year, they found that ancient galaxies in that section of sky — like, ten billion years old kind of ancient — had high concentrations of carbon monoxide, which is associated with star formation.
去年，天文学家发现，这片天空的远古星系——大概有100亿年的年龄了——聚集着高浓度的一氧化碳，而一氧化碳会影响恒星形成。
They already knew that around the same time, there was a huge peak in star formation in the universe.
天文学家已经知道，差不多100亿年前的时候曾是恒星形成的高峰期。
But they weren't sure what caused all that star formation — until they used ALMA to observe those early galaxies, and found the abundance of carbon monoxide.
但他们不确定是什么促成了这个高峰期——直到他们用ALMA观测了早期的一些星系，才发现那时候存在大量的一氧化碳。
And now we know that the gas must have provided the right conditions for the stellar baby boom.
而现在，我们知道，一氧化碳一定为恒星形成的高峰期提供了合适的条件。
ALMA has also helped us learn why some of the largest objects in the universe are glowing — specifically, these ridiculously ancient, huge structures called Lyman-alpha blobs.
ALMA已经帮助我们了解到宇宙里一些最大型物体不断涌动的原因——准确地说，这些物体来自很早之前，它们体型庞大，叫做莱曼α斑点。
They're called that because they have very a well-defined Lyman-alpha spectral line, a specific wavelength of ultraviolet light that's emitted by hot hydrogen gas.
之所以得名于此是因为他们有十分清晰的莱曼α光谱线，而莱曼α光谱线是紫外线的一种特殊波长，这种紫外线是由高温氢气释放出来的。
So we knew that there were these enormous, luminous clouds of hydrogen just floating around in space, but we had no idea why they were glowing. Enter ALMA.
所以我们知道，宇宙里涌动着这样一些体量很大、亮度很强的氢云，但我们不知道这些气体涌动的原因。这时候又需要ALMA登场了。
Astronomers using ALMA found galaxy clusters inside the Lyman-alpha blobs.
通过ALMA，天文学家发现莱曼α斑点中存在星系团。
And it turns out that these galaxies are forming stars at an incredibly high rate, and emitting lots of Lyman-alpha radiation because of all the hydrogen in those stars.
原来是这些星系一直在以惊人的速度形成新的恒星，同时由于恒星中存在许多氢气而释放出大量莱曼α辐射。
The radiation then scatters off of the surrounding gas cloud, and we see an enormous blob.
随后，辐射会在周围的气体云中四散开来，所以我们能看到一个巨大的斑点。
And now we know why Lyman-alpha blobs glow: it's because of all the galaxies making stars inside them.
现在我们终于知道莱曼α斑点为何会涌动了：因为其中有很多星系在不断的形成新的恒星。
So even though ALMA's only been around for a few years, it's already taught astronomers a ton about the universe.
所以，虽然ALMA只出现了数年之久，但已经让天文学家了解了宇宙的很多知识。
And with the constant flurry of papers being published with discoveries made using ALMA, we're always learning more.
而且不断有论文发表，内容都与在ALMA帮助下所做的发现有关，借助这写论文，我们也了解了更多。
Thanks for watching this episode of SciShow Space, and thanks especially to our patrons on Patreon who help make this show possible.
感谢收看本期的《太空科学秀》，尤其要感谢我们的忠实粉丝，是你们支持了节目的发展。
If you want to help us keep making episodes like this, just go to patreon.com/scishow to learn more.
如果您想要帮助我们制作类似本期的视频的话，请登录patreon.com/scishow了解更多吧！
And don't forget to go to youtube.com/scishowspace and subscribe!
别忘记订阅youtube.com/scishowspace哦！
