(单词翻译:单击)
With all the bigger cosmological mysteries like dark matter, dark energy,
我们有了更大的宇宙奥秘，比如暗物质、暗能量，
and what happens at the center of a black hole,
以及黑洞中心的情况，
you might think a question as local as "How was our solar system born?" was solved a long time ago.
你就可能会认为“太阳系如何诞生的”这个小问题很久以前就解决了。
Nope. But we might be a little closer to solving that puzzle,
不是的，但我们可能更接近这个谜题了，
thanks to a new paper published in the Astrophysical Journal a couple of weeks ago.
这多亏了几周前发表在《天体物理学杂志》上的一篇新论文。
Right now, the most widely-accepted hypothesis about how the Solar System came to be
现在，关于太阳系如何形成的最广为接受的假说是
starts about 5 billion years ago with a nearby supernova, an exploding star.
它开始于50亿年前的一颗邻近超新星，后者是一颗爆炸的恒星。
The shockwave from the explosion would have triggered the collapse of the large cloud of gas and dust
爆炸产生的冲击波引发了大量气体和尘埃的坍塌，
that eventually became the sun, planets, and all the other stuff in the Solar System, including us, eventually.
最终形成了太阳、行星以及太阳系的所有其他物质，包括我们。
But here's the problem.
但有一个问题。
A supernova would also infuse our cloud with certain elements.
超新星也会给我们的星云注入一些元素。
They release aluminum-26, a type of aluminum with 13 neutrons,
它们释放铝26，一种含13个中子的铝，
and iron-60, a type of iron with 34 neutrons that you can only get from the explosion of a massive star.
和铁60，它是一种含34个中子的铁，你只能从大质量恒星的爆炸中得到它。
The thing is, the amount of aluminum-26 and iron-60 we've measured in our solar system
问题是，我们在太阳系中测到的铝26和铁60的量
doesn't match what we should have gotten from a supernova.
不符合我们应该从超新星中得到的量。
Meteorites, which are a good way to measure the composition of the Solar System since they come from space,
陨石是测量太阳系成分的好方法，因为它们来自太空。
do have more aluminum-26 than what we find on average across the galaxy.
它们中铝26的含量比我们在星系中发现的铝平均值要高。
But we're low on iron-60.
但我们铁60的含量要低。
And a supernova would have injected both into our system, not just extra aluminum.
而超新星会向我们的太阳系注入这两种物质，而不仅仅是额外的铝。
So in this new paper, a group of astronomers proposed a different idea:
所以在这篇新论文中，一组天文学家提出了一个不同的想法：
maybe the Solar System didn't start with a supernova.
也许太阳系不是从超新星开始的。
Maybe it started with the wind-blown bubble surrounding a star 40-50 times the mass of the sun,
它可能是从40-50个太阳质量的恒星周围的“风泡”开始的，
a type of star called a Wolf-Rayet star.
即沃尔夫拉叶星。
Wolf-Rayet stars are basically the most massive and hottest-burning class of stars in the universe.
沃尔夫拉叶星基本上是宇宙中质量最大，也是最热的恒星。
They've already exhausted all their hydrogen fuel,
它们已经耗尽了所有的氢燃料，
so they're fusing heavier elements instead, and they have a really hard time holding themselves together.
于是熔化更重的元素，它们很难保持一体。
Their stellar wind, the gas streaming out from the star is so strong
它们的恒星风，即从恒星涌出的气体非常强，
that they lose about 3 Earths' worth of mass every year.
以至于每年损失大约3个地球质量。
The violence inside them forces heavier elements upward too,
它们内部的暴力也迫使较重的元素上升，
so it's not just a bunch of helium getting spewed out into space.
所以这不仅仅是一堆氦气喷射到太空中。
In fact, Wolf-Rayet stars release a lot of aluminum-26, but not iron-60.
事实上，沃尔夫拉叶星释放出大量的铝26，而不是铁60。
Which sure sounds a lot like our solar system!
这和我们的太阳系多么相似啊！
These stars' high-velocity winds and extreme temperatures create a huge bubble structure,
这些恒星的高速气流和极端温度形成了一个巨大的气泡结构，
including a shell of denser gas and dust that could eventually condense into stars.
包括一层致密的气体和尘埃，它们最终会凝结成恒星。
Based on their computer simulations,
基于研究小组的计算机模拟，
the team estimates that anywhere between 1-16% of all sun-like stars could be formed in Wolf-Rayet star wind bubbles.
他们估计，有1-16%的太阳类恒星有可能在沃尔夫拉叶星的“风泡”中形成。
Of course, we don't know for sure.
当然，我们还不确定是这样。
For one thing, this model assumes the meteorite data gives us a true representation of what the early solar system looked like,
首先，这个模型假设陨石的数据给了我们一个太阳系早期的真实样子，
which we'll never actually now for sure without a time machine.
由于没有时光机器，我们现在还不能肯定。
This is a very new hypothesis, and until we have more research,
其次，这是一个非常新的假设，除非我们有更多的研究，
most astronomers are probably going to stick with the supernova idea for now.
否则大多数天文学家可能会坚持现在的超新星想法。
But it does fit pretty nicely.
但它现在确实很符合条件。
While some astronomers are working on solving that 5 billion-year-old puzzle,
当一些天文学家正在致力于这个50亿年前的谜题时，
others are continuing to explore the system we call home.
其他人仍在继续探索我们称之为家的星系。
And now we've taken the next step in planning another mission!
现在我们已经在计划另一个任务的下一步了。
In late December, NASA announced two finalists for the next New Frontiers mission, which both sound awesome:
12月下旬，宇航局宣布了两项“新疆界计划”的最终入围任务，这两项任务听起来都很棒：
One would sample a comet, and the other would send a nuclear-powered quadcopter to Titan, Saturn's largest moon.
一个是对彗星取样，另一个是向土星的最大卫星——土卫六发射一个核动力四轴飞行器，
Even if you've never heard of the New Frontiers mission program by name,
即使你凭名字从未听说过“新疆界计划”，
you've probably heard about at least one of the three missions that came out of it:
但你至少可能听过它三个任务中的一个，
New Horizons, Juno, and OSIRIS-REx.
它们分别是“新视野号”、“朱诺号”以及“奥西里斯-REx”任务。
The first of the two finalists bidding to be the fourth member of this special club
这两个入围任务中，第一个竞标成为特殊俱乐部
is the Comet Astrobiology Exploration Sample Return mission, or CAESAR.
“彗星天体生物学探索取样返回”（CAESAR）的第四个成员。
It would be a follow-up to the ESA's Rosetta mission,
它将是欧洲太空总署“罗塞塔”任务的后续，
which visited and landed the Philae probe on comet 67P/Churyumov-Gerasimenko in 2014.
后者在2014年发射Philae探测器访问并降落在67P/丘留莫夫-格拉西缅科彗星上。
But CAESAR would go beyond that mission,
但Philae要超越这一任务，
it would actually collect a 100-gram sample of the comet's surface and return it to Earth.
它实际上会收集100克彗星表面的样本并将其返回地球。
The Japanese space agency JAXA would use its experience from their asteroid sample return mission Hayabusa
日本太空总署（JAXA）将利用从Hayabusa任务返回的小行星样本得出的经验，
to design CAESAR's return capsule, which would return to Earth in November 2038.
设计CAESAR的返回舱，它将于2038年十一月返回地球。
That might seem pretty far-off, but this is a whole new space mission we're talking about.
这看起来很遥远，但它是我们正在讨论的一个全新太空任务。
It takes a lot of planning!
它需要很多计划。
If the Dragonfly mission is selected instead, it would arrive at Titan by 2034.
如果选择“蜻蜓”任务，它将于2034年到达土卫六。
Like 67P, we've landed on Titan before, with the Huygens probe, back in 2005.
像67P一样，2005年，“惠更斯号”探测器降落在土卫六上，
It even sent back pictures of the surface.
它甚至发回了其表面的照片。
But this time we'd get to go flying.
但这次我们可以飞了。
With Titan's low gravity and super thick atmosphere,
因为土卫六重力低，大气层超级厚，
you could actually fly around by just strapping on wings and flapping your arms a bunch,
你只需拍拍翅膀、拍打手臂就可以飞来飞起。
which sounds like the best thing ever.
听起来是最棒的事儿了。
But it's tough to send an astronaut all the way out there when we haven't even gotten one to Mars yet,
但是当我们还没到达火星时，很难把宇航员送到那里，
so a quadcopter is the next best thing.
所以四轴飞行器是最好的选择。
Because of all those clouds and Titan's distance from the sun, solar power isn't an option.
因为星云和土卫六与太阳的距离，太阳能并不是唯一选择。
So, like a certain famous DeLorean time machine from the 1980s, it would be powered by plutonium.
所以，就像二十世纪八十年代著名的德洛雷安时间机器一样，它将由钚提供动力。
Legally acquired, though.
不过，得合法获得。
And the waste heat produced by the generator would be used to keep the electronics from getting too cold.
发电机产生的余热将用来防止电子设备变得太冷。
Dragonfly would land at a bunch of different geologic sites covering hundreds of kilometers,
“蜻蜓”会降落在很多不同的地质区域，覆盖数百公里，
and use a drill to sample pieces of Titan's surface and analyze its composition.
然后用钻头对土卫六的表面进行取样并分析其成分。
That includes hunting for chemical signatures that could indicate the presence of life.
这包括寻找能显示生命存在的化学信号。
It would also look for any possible seismic activity and profile atmospheric conditions,
它还将寻找任何可能的地震活动和剖面大气条件，
giving us a better sense of what life would be like on this weird alien moon where it rains methane instead of water.
让我们更加了解这颗奇怪陌生的卫星，它下甲烷而不是水。
The teams working on both projects will receive funding through the end of 2018 to keep developing them,
这两个项目的工作团队将在2018年底之前获得资金，以便继续开发，
and NASA will select the winner in spring of 2019.
而宇航局将在2019年春天选择胜利者。
So I guess we'll just have to stay tuned to find out which project gets the go-ahead.
所以我想，我们只能继续关注，看看哪个项目能取得进展了。
So make sure to hit that red subscribe button because we're so close to a million subscribers on Scishow Space.
所以一定要点击那个红色订阅按钮，因为我们“太空科学秀”的用户非常接近一百万了。
And in the meantime, thanks for watching this episode of SciShow Space News,
同时，感谢您收看本期的太空科学秀，
and if you're interested in learning more about Titan,
如果你对土卫六感兴趣，
we have a video about that that you could watch.
我们有关于它的视频，你可以观看。
