(单词翻译:单击)
Even though it can sound all futuristic and sci-fi,
尽管天文学听起来赋有未来主义和科幻色彩，
sometimes, astronomy is just about studying stuff that's really old.
但有时，它只是研究那些真正古老的天体而已。
And the older it is, the cooler it gets.
天体越古老越有趣。
On Monday, astronomers published a paper in the journal Nature Astronomy announcing that
星期一，天文学家在《自然天文学》杂志上发表了一篇论文，声称，
they've found one of the oldest galaxies we've ever seen: a galaxy named G09 83808.
他们发现了一个最古老的星系，名为G09 83808。
Which, somehow, is the shortened version of its name.
这是它缩减的名字。
It formed 12.8 billion years ago, making it less than a billion years younger than the universe itself.
它在128亿年前形成，比宇宙本身年轻10亿岁。
It's what astronomers call a dusty, star-forming galaxy, or one that produces hundreds of stars each year.
天文学家们称它是布满尘埃的产星星系，或每年产生数百颗恒星的星系。
And it's the third-oldest one we've ever found, behind ones that formed 880 and 716 million years after the Big Bang.
它是我们发现的第三古老星系，排在大爆炸后8.8亿年和7.16亿年形成的星系之后。
The galaxy was first spotted in 2012 by the orbiting Herschel Space Observatory,
该星系最初是由轨道上的赫歇尔太空天文台于2012年发现的，
but it wasn't powerful enough to see it clearly.
但由于它不够强，看不清楚。
So the real star of this story is the Large Millimeter Telescope, or LMT, in Mexico,
所以这个故事真正开始于墨西哥的大型毫米波望远镜，
which started observing the galaxy in 2014.
它从2014年开始观察该星系。
The LMT was designed to study the farthest, faintest objects in the universe, including galaxies like this one.
大型毫米波望远镜的设计是为了研究宇宙中最遥远、最微弱的天体，包括这样的星系。
Like other telescopes, it calculates the object's distance using its redshift,
和其他望远镜一样，它利用红移
or how red its light looks because of the universe's expansion.
或由于宇宙膨胀，天体的光看起来有多红来计算天体的距离，
See, as the universe expands, the light from distant galaxies gets stretched, too.
看，由于宇宙膨胀，遥远星系的光也开始延伸，
That gives the light a longer wavelength, which means that by the time we see it,
这使得光波被拉长，也就是说我们看到它的时候，
it's been shifted toward the redder, longer side of the spectrum.
它转移至了光谱中更红、更长的区域。
By measuring how much the light has shifted, whether it's white light that looks red,
科学家们通过测量光转移的多少，不管是白光看起来多红，
or radio waves with a longer wavelength than normal,
还是无线电波的波长比正常波长长，
scientists can get a good idea how far away the object is.
他们都能很好地了解天体的距离。
Even though telescopes like the LMT are powerful,
即使大型毫米波望远镜之类的望远镜很强大，
they aren't strong enough to observe galaxies this far away on their own.
但它们还不能单独观察这么远的星系。
To find this one, scientists got a little help.
为了找到这个星系，科学家们获得了一点儿帮助。
But it wasn't from another telescope, it was from an effect known as gravitational lensing.
但这个帮助不是来自另一架望远镜，而是来自引力透镜效应。
Conveniently, there was another large galaxy between us and 83808.
在我们和83808之间恰巧还有一个巨大星系，
It was in just the right spot, and was so massive that the light bent around it,
它的位置刚刚好，而且很大，以至于它周围的光都弯曲了，
magnifying 83808 and making it look about 10 times brighter than normal.
这会放大83808，使它看起来比正常情况明亮10倍左右。
Studying ancient galaxies like this can teach us more about the timeline of the universe.
研究这类古老星系能告诉我们更多宇宙时间轴的事情。
Astronomers think galaxies started forming between 200 million and a billion years after the Big Bang,
天文学家们认为宇宙是从大爆炸后的2亿年至10亿年间开始形成的，
and because of its age, this discovery supports that idea.
因为年龄的问题，这个发现支持了这一想法。
And maybe the coolest part about all of this is that even though the LMT is helping us make discoveries,
也许最酷的部分是，LMT尽管帮助我们有所发现，
it isn't even at full capacity yet!
但这还不是它的全部能力！
At first, it was only about 30 meters in diameter, but now,
起初，它的直径只有30米，但现在，
it's fully-built and is 50 meters across, and will be ready for more science this January.
它全部建成，直径达到50米，这样今年一月就会有更多的科学发现了。
So, pretty soon, we'll be checking out even more galaxies from a long, long time ago, far, far away.
所以不久，我们就能调查更多古老遥远的星系了。
Closer to home, another team of astronomers has developed a new method for finding habitable exoplanets.
回到国内，另一组天文学家们已经开发出一种寻找可居住系外行星的新方法。
And their strategy, published in the journal Scientific Reports last week, could save astronomers a lot of time.
他们的策略上周发表在《科学报告》杂志上，它可以为天文学家们节省很多时间。
A habitable exoplanet can refer to a lot of things,
可居住系外行星可以指很多东西，
including planets in the right orbit around their stars, or ones with liquid water.
包括行星在围绕它们主恒星的正确轨道上或有液态水。
But this method specifically searches for planets with an atmosphere we could breathe.
但这种方法特别搜索了有可呼吸大气的行星。
Normally, scientists hunt for habitable exoplanets by looking for molecules like oxygen and methane,
通常，科学家们通过寻找氧气和甲烷之类的分子来寻找可居住系外行星，
which are made by plants and animals here on Earth.
而这类分子是由地球上的动植物制造的。
Unfortunately, that method can take days of observation,
不幸的是，这种方法需要几天的观察，
which isn't always possible when everyone wants a piece of those fancy space telescopes.
当每个人都想要一台昂贵的太空望远镜时，这并不总是可行的。
This new method finds habitable planets by searching for the byproducts of stellar storms.
新方法通过寻找恒星风暴的副产品来寻找可居住行星。
And instead of taking days, it only takes a few hours.
它不用花几天的时间，几个小时就够了。
So far, we haven't tested it out on any exoplanets, but we know the idea works on Earth.
目前，我们还没有在任何系外行星上测试，但我们知道它在地球上起作用。
Plenty of stars, including our sun, have the occasional storm,
很多恒星，包括太阳，偶尔会有风暴，
where they release high-energy particles into space.
它们会释放高能粒子到太空。
On Earth, you often hear about them causing the northern and southern lights.
在地球上，你经常能听到它们制造北极光和南极光的消息。
But those storms also kickstart a chemical reaction in our atmosphere.
但这些风暴也会在我们的大气中引发化学反应。
The particles react with the atmosphere's nitrogen and oxygen to create three molecules:
这些粒子与大气中的氮和氧反应生成3个分子：
hydroxyl, or hydrogen and oxygen atoms bonded together;
羟基，或氢原子和氧原子结合在一起的产物；
nitric oxide, which is one nitrogen and oxygen; and plain old molecular oxygen.
一氧化氮，是氮氧化物；普通的分子氧。
These molecules aren't a definite sign of an Earth-like atmosphere,
这些分子并不是类似地球大气的确切标志，
but they're so important that the authors of the paper call them "atmospheric beacons of life."
但它们非常重要，以至于论文作者称它们为“大气生命的信号”。
And we can detect them with space telescopes.
我们可以用望眼镜来探测它们。
We're most familiar with the reaction on Earth, but it isn't limited to us:
我们最熟悉地球上的反应，但它不只在地球上：
Any planet with a lot of nitrogen and oxygen in its atmosphere would react this way if it got hit with a stellar storm.
任何含有大量氮气和氧气的行星如果受到恒星风暴的影响，都会以这种方式发生反应。
So, if we scan for atmospheric beacons around planets with stormy stars,
所以如果我们观察行星周围是否有大气生命的信号，前提是这行星围绕爆发风暴的恒星旋转，
we could find habitable planets with an atmosphere like Earth's.
就能发现有类似地球大气的可居住行星。
We'd still be limited to planets we could see directly,
我们仍被直接看到的行星所限，
but scientists estimate we'd be able to find beacons with a telescope smaller than the Hubble Space Telescope.
但科学家们估计我们能够用比哈勃天文望远镜小的望远镜寻找生命信号。
And if we did, we could use newer telescopes, like the James Webb Space Telescope,
如果我们这样做，就可以使用更新的望远镜了，如詹姆斯·韦伯太空望远镜，
which will launch in 2019, to take a closer look at the planets with those beacons.
它将于2019年发射，更近的观察有生命信号的行星。。
Researchers are always on the hunt for new, habitable exoplanets,
研究人员一直在寻找新的可居住系外行星，
so this might be the start of an exciting new chapter in astronomy.
所以它可能是天文学激奋人心的新一章的开始。
Now, those beacon molecules could still exist around a planet without an Earth-like atmosphere,
现在，这些信号分子仍然可以在没有类似地球大气的行星上存在，
so we'll need to be sure we know what else could cause those signals too,
因此，在得出结论之前，
like volcanoes, before we jump to conclusions.
我们需要知道引起这些信号的其他物质，如火山。
But since this method takes less time, it will let us scan a lot more planets.
但由于这种方法花的时间少，所以我们可以观察更多的行星。
So maybe someday, besides having more old galaxies to study,
或许某一天，研究人员除了研究更多的古老星系之外，
researchers might also have a whole long list of habitable exoplanets, too.
还要研究一长串的可居住行星。
Thank you for watching this episode of SciShow Space!
感谢您收看本期的太空科学秀！
And a big thanks to our patrons on Patreon who make SciShow Space exist,
我们也要非常感谢Patreon对本节目的大力支持，
and make it free and available to everyone. Thank you!
感谢你们向每个人免费开放。谢谢！
If you'd like to help us keep making episodes like this, you can go to patreon.com/scishow.
如果你想帮助我们继续制作这样的节目，就登陆patreon.com/scishow吧！
