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SciShow Space is supported by Brilliant.org.
《太空科学秀》由Brilliant.org赞助播出。
We've got another discovery to add to the growing list of surprises astronomers have uncovered about the early universe recently.
最近，天文学家们对于宇宙初期的情况又有了一个新的发现。
In a paper published last week in the journal Nature,
在上周《自然》杂志发表的一篇文章中，
an international group of researchers announced that they'd found a pair of galaxies from the first billion years of the universe.
某个国际研究小组宣布，他们发现了宇宙最初10亿年间的一组星系对。
And they're almost impossibly big for their age.
而且它们比同期产生的其他星系要大很多。
The first galaxies started forming a few hundred million years after the Big Bang,
它们是在宇宙大爆炸之后的几亿年后产生的，
and for the most part, we assumed they were fairly small, irregularly shaped collections of a few billion stars, similar to modern dwarf galaxies.
我们一直以为它们大多都很小，以为它们是由几十亿颗恒星组成的形状不规则星系，以为与现代的矮星系很像罢了。
Those small galaxies would then act as building blocks,
但是，这些小星系又作为组成因素，
merging together over the next billion or so years to form the much larger galaxies we're used to seeing.
并合在一起十亿年左右之后，形成了我们如今经常看到的规模更大的星系。
Problem is, the pair of galaxies the researchers describe in their paper,
问题是，研究人员在文章中提到的那组星系对，
which is from about 780 million years after the Big Bang, doesn't really fit that description.
虽然是形成于宇宙大爆炸的大概7.8亿年后，但并不符合那样的描述。
Looking so far back in time is difficult because everything is really far away and incredibly dim.
回看时间这么久远的东西很难，因为离得太远，太过模糊了。
To study this pair, the team used the ALMA observatory in Chile to take advantage of an effect called gravitational lensing,
为了研究这组星系，该研究小组借用了智利的大型无线电望远镜阵列ALMA，因为该望远镜有引力透镜的效果。
which is where the gravitational pull of a large galaxy between us and the object of interest warps that object's light, making it look brighter.
通过这种效果，人类与其感兴趣的大型星系间的万有引力就会扭曲这个物体发出的光，增加其观测时的亮度。
Unfortunately, the lensing also heavily distorts the image,
但ALMA望远镜也有一个缺点，那就是它的透镜会严重扭曲成像效果。
so the researchers needed to use computer modeling to calculate things like how far away it is and how much mass it has. Turns out a lot.
所以研究人员需要使用计算机模拟的方法来计算距、质量等参数，计算结果大的出人意料。
They found that the larger of the two galaxies has a mass of gas and dust over 270 billion times the mass of our Sun about 3-5 times as much as the Milky Way.
他们发现，两个星系中较大的那个的气体和尘土的质量是太阳的2700多亿倍，是银河的3-5倍。
This makes it the most massive object ever detected from the first 950 million years or so of the universe's history.
使之当之无愧地成为宇宙史上大约前9.5亿年里所感测到的质量最大的物体。
The other galaxy is much smaller, coming in at just 35 billion solar masses,
另一个星系更小一些，是太阳的350亿倍，
but for its time, it's actually pretty impressive in size, too.
不过，其体积也相当的大。
But both are nothing compared to the amount of dark matter they're embedded in,
不过，与它们两个所镶嵌的暗物质的体量相比就微不足道了，
which the team estimated to be a few trillion solar masses.
因为据该研究小组估测，它们所镶嵌暗物质的质量是太阳的几万亿倍。
Dark matter makes up nearly 85% of all the matter in the universe.
暗物质占宇宙总体量的85%。
It doesn't interact with light at all, which is why it's been so hard to figure out what it's made of.
暗物质不与光反应，所以很难得知其组成。
But we know it's there based on how its gravitational pull affects the regular matter we can see.
但我们已知的一点是其万有引力对我们常见的事物造成了巨大的影响。
While the dark matter around this pair is roughly equivalent to the amount of dark matter in and around our own galaxy,
虽然这两个星系附近的暗物质大体上与太阳系内和太阳系附近的暗物质体量差不多，
astronomers have found that early galaxies tend to have much less dark matter relative to their size.
但一些天文学家发现，宇宙初期一些星系的暗物质要比如今同等大小的星系少很多。
It would be more like finding a modern galaxy with 10,000 trillion solar masses of dark matter, instead of just a few trillion.
今天很容易就能找到质量是地球1亿亿倍的太阳质量，几万亿倍的更是不在话下。
That's how extreme this is.
对，就是大得如此惊人。
All together, these galaxies and their dark matter almost break the current models astronomers have for early galaxy formation.
这些星系及其暗物质的存在几乎打破了天文学家为宇宙初期星系形成而构造的模型。
Like, the math still technically works, but barely.
与刚才所说的类似，数学计算在技术上虽然可行，但并没有卵用。
And that's not all, we're also seeing the two galaxies right before they merge.
更糟心的是我们正在观测这两个星系在并合之前的过程，
Their centers are as close together as our solar system is from the center of the Milky Way. So this pair of galaxies is super weird.
并发现这两个星系中心的距离很近，就跟太阳系与银河系的距离一样近，这就很奇怪了。
And it'll be interesting to see how scientists use the data from this new discovery in future research
科学家会怎样将这一新发现用于未来的研究就成了一件有意思的事情，
on how and when galaxies started forming in the early universe.
比如研究各个星系是从宇宙初期的什么时候开始，并以怎样的方式形成的。
Closer to home, NASA announced last week that the Opportunity rover has officially made it through the worst of its eighth Martian winter.
而上周，美国宇航局宣布，其机会号火星车已经正式挺过了其在火星的第八个冬天，也是最难熬的一个冬天。
But a planet-wide dust storm might be on the horizon. Unlike the radioactively-powered Curiosity rover,
不过火星全境可能很快就要起尘暴了，好奇号火星车是由放射性物质提供能源的，
Opportunity relies on solar power to keep running, and sunlight comes at a premium during the winter.
而机会号火星车则依赖太阳能运转，然而冬天的日光少之又少。
Since the rover is in Mars's southern hemisphere,
机会号目前在火星的南半球，
the mission team has to position it on angled ground so its solar panels are tilted northward, toward the Sun.
任务组要把机会号放在有特定角度的地面上，这样它的太阳电池板就能朝向北面的太阳。
That might not sound like a big deal, but Opportunity's twin Spirit failed to survive their fourth Martian winter back in 2009
这听起来挺容易的，但与机会号一起出世的勇气号就没能挺过在火星的第四个冬天，2009年阵亡了。
because two of its wheels broke and it couldn't maneuver itself into a position where it could capture enough light to keep running.
当时是因为勇气号的两个轮子都坏了，没法移动到能获取更多日光以维持运转的地方。
And during the very next winter, Opportunity found itself stuck in one spot for 19 weeks
次年，机会号也遇到了问题：卡在一个地方整整19周动不了，
because there were no places within driving distance that could provide the necessary tilt.
因为电力所及之处都无法提供合适的角度。
It's in a much better location now, though inside the western edge of what's known as Endurance Crater,
虽然现在的位置好点儿了，在众所周知的耐力陨石坑西部，不过是在边缘上，
where there's plenty of angled ground.
那里的地面坑坑洼洼，可以提供很多角度。
But the tilt of its solar panels isn't the only thing Opportunity has to worry about to get enough light during the winter months.
但太阳电池板的倾斜角度并不是机会号要担心的唯一问题，还有其他因素也让机会号的冬天不好过。
Dust is another main obstacle both the particles that get kicked up into Mars's thin atmosphere during storms, and those that settle on the rover's solar panels.
另一个主要的障碍在于尘土：尘土会在尘暴期间进入火星稀薄的大气中，也会滞留在机会号的太阳电池板上。
Continent-sized storms happen every year or so,
星球规模的尘暴大概一年左右发生一次，
and because there's so little water in the atmosphere, the dust can hang around in the air for weeks.
而且由于大气中水分极少，所以尘土会一直滞留在大气中长达数周之久。
In July 2007, a planet-wide dust storm forced Opportunity to shut down all non-vital systems
2007年7月，火星就发生了这样一次大规模尘暴，导致机会号不得不关闭所有的非关键系统。
when the surrounding dust blocked 99% of direct sunlight and it lost 80% of its power output.
当时，机会号周围的尘土阻碍了99%的直接日光，导致其失去了80%的能源输出。
It took six weeks for the rover to get back to work.
耗时整整六周，机会号才得以重新运转。
Mars hasn't had a planet-wide storm like that since Opportunity's brush with death a decade ago.
那次之后的十年间，机会号再也没遇到过火星全境范围内的尘暴了。
But the average length of time between those giant storms is 3 Martian years, or 5.5 Earth years.
但这两场大规模尘暴之间的时段是三个火星年，也就是5.5个地球年。
That doesn't necessarily mean you can expect a massive storm every 3 years,
我这句话的意思并不是说每三年就要发生一场大型尘暴，
but atmospheric scientists aren't sure why it's been so long since the last one.
但有一些大气科学家不太明白两场尘暴之间为何相距如此之久。
Some think the next one might happen in 2018, as Mars’s orbit takes it closer to both the Sun and the solar system's center of gravity.
一些人认为，下一次尘暴或将于2018年发生，因为2018年火星的轨道离太阳以及太阳系的重心更近。
Even if we do get another planet-wide storm next year, the mission team is optimistic.
即便火星明年真的发生全境规模的尘暴，任务组的态度也是十分积极的。
Back in the Martian autumn, Opportunity's panels were the second dustiest they'd ever been.
火星秋天的时候，机会号的太阳电池板是第二脏的时候。
But they've gotten much cleaner since then thanks to some wind.
不过从那以后，由于有了些许的风，所以太阳电池板已经干净多了。
At most, Opportunity might have to put its exploration on hold for a bit while it waits for more wind and sunlight.
最坏的情况也就是机会号可能要在等风和日光来的期间暂时停止探索活动。
Not bad for an almost 14-year-old rover that was only supposed to run for 90 days.
这也不错啊，毕竟机会号已经快14岁了，而且本来的计划也只是让它维持90天的运转而已。
Like with that almost impossibly large pair of galaxies, sometimes life in space is all about defying the odds.
就像今天一开始提到的那组星系对一样，有时候宇宙间生命的法则挑战不可能。
The main reason we've been able to learn about those galaxies or anything else from the early universe is Hubble's Law,
我们能有机会了解各种星系以及宇宙初期其他物体的主要原因是因为有哈勃定律的存在。
which lets you take advantage of the fact that light travels at a constant Speed to calculate an ancient galaxy's distance and age.
哈勃定律让人类可以通过光以恒定速率传播的事实来计算远古星系的年龄及其距离地球的距离。
SciShow's sponsor, Brilliant, helped rekindle my understanding of Hubble’s law with an interactive lesson in their Astronomy unit.
我们节目的赞助商Brilliant就通过他们一节具有互动性的天文学课帮助我对哈勃定律有了新的理解。
So in this first one, you're standing on a bike path beside a train, and you're facing a train that's going perpendicular to you.
比如说，你正站在某辆火车旁边的自行车道上，有一列火车与你方向垂直地行驶。
The train goes along at 40 mph, they leave the station every 10 minutes and travel in the same direction.
这列火车时速40英里，每10分钟发一列车，开往同一个方向。
So, how many trains go past in an hour. So, six.
那么，每小时经过了多少列火车呢？六列，对吧？
Now you're finally riding your bike at 20 mph in the same direction as the train, so that halves your answer, and you get three.
现在呢，你终于起步了，以时速20英里的速度，与火车同方向开去，这回就变一半了，是三列。
Going the other way, you get more, because you're going opposite the direction of the train, so you're going to see more trains.
如果你朝着反方向走呢，答案的数值就更大，因为反向行走能看到更多的火车。
So, nine. I got that right! I just....What a cool way to look at this.
那就是九咯。我可是答对了哦！这样看待问题的方式真的很酷。
If you are biking away from the source of a green light and you pedal quickly enough.
如果你骑得够快，与绿色光源渐行渐远的话，
Like, you'd have to go really, really fast. What would happen to the light?
我说的快是要多快有多快的那种，光会发生什么变化呢？
When I was biking away from the train, I was seeing the trains less frequently.
我骑车离火车越来越远的时候，我看到火车的频率也在降低。
So I would be seeing the waves of the green light less frequently, so the waves would be longer in between, so that would be red light.
也就是说，我看到绿色光波的频率也在降低，所以它的波长会变长，介于两者之间，也就是红光咯。
AH! I got it! So that was a fun one and I'm going to keep playing it.
啊！我明白了！这个很有意思，可以继续推演下去
But I don't want to tell you all the answers and I don't want you to start seeing when I get the wrong. So you should go check them out too!
不过我不想告诉你们所有答案，我也不想让你们跟我一起算错，所以你们也要一起算啊！
And the first 200 people to sign up at https://brilliant.org/scishowspace will get 20% off their annual subscription and support SciShow Space.
前两百名在https://brilliant.org/scishowspace注册的用户会减免20%的年度订阅费，也是对《太空科学秀》的一种支持哈。
So, thank you!
谢谢大家！下期见！
