This episode is sponsored by The Ridge.

本期节目由The Ridge赞助

Go to ridge.com/scishow and use promo code “scishow” to get 10% off your next order.

登录ridge.com/scishow 使用“scishow”优惠码 下次下单可享受10%的折扣

You’ve probably heard of the butterfly effect.

你可能听说过蝴蝶效应

It’s the idea that tiny actions can set off big, seemingly-unrelated events — like, how a butterfly flapping its wings in your hometown could lead to a tornado far away.

它是指 微小的行为可以引发看似无关的大事件——比如 一只蝴蝶在你的家乡扇动翅膀 可能会引发远方的龙卷风

And while butterflies aren’t responsible for all the extreme weather in the world, the general idea of small inputs affecting big systems is true.

虽然蝴蝶并不是世界上所有极端天气的罪魁祸首 但小的输入会影响大的系统这一普遍观点是正确的

So now... imagine that the butterfly is a whole galaxy.

所以现在…把蝴蝶想象成一个星系

And instead of flapping its wings, it’s crashing through the Milky Way.

它没有扇动翅膀 而是穿过银河系

Doesn’t really sound the same, does it?

听起来不大一样 是吧?

But according to research published last week in the journal Nature Astronomy, that act billions of years ago might be the reason you are around to watch this video today.

但根据上周发表在《自然天文学》杂志上的一项研究 发生在数十亿年前的这种行为 可能就是你今天在观看这个视频的原因

Or, at least, it might be the reason the Sun exists. Which was an important step!

或者 至少可以说它就是太阳存在的原因这一步很重要!

The study looked at how collisions with a dwarf galaxy named Sagittarius have shaped the Milky Way throughout history.

这项研究观察了一个叫做人马座的矮星系的碰撞是如何在整个历史中塑造了银河系的

Sagittarius orbits so close to the Milky Way that scientists believe the two have actually collided three times over the last six billion years.

人马座的轨道离银河系非常近 所以科学家们相信 在过去60亿年里 这两颗行星实际上已经相撞了三次

But for this study, astronomers didn’t look at the dwarf galaxy itself.

但是在这项研究中 天文学家并没有观察矮星系本身

Instead, they tracked its effect on the stars around us.

相反 他们追踪它对我们周围恒星的影响

And to do that, there was no better tool than the European Space Agency’s Gaia satellite, which launched in 2013.

要做到这一点 没有比欧洲航天局2013年发射的盖亚卫星更好的工具了

In astronomy, most missions are designed to study what something is, but Gaia performs astrometry, which measures where an object is and how it’s moving.

在天文学中 大多数任务都是为了研究某样东西是什么 但是盖亚进行的是天体测量 即测量一个物体的位置以及它是如何移动的

Specifically, it measures the precise positions, distances, and velocities of more than a billion nearby stars.

具体来说 它可以测量附近10亿多颗恒星的精确位置、距离和速度

That’s incredibly powerful because, if you know how something is moving, you can basically turn back the clock to see where it must have come from.

这真的非常强大 因为如果你知道一个东西是如何运动的 那基本就可以让时光倒流 看看它来自何处

In this new study, researchers noticed three clear periods of past star formation in the Milky Way, each corresponding to one of the collisions with Sagittarius.

在这项新的研究中 研究人员注意到银河系过去有三个清晰的恒星形成周期 每一个都对应着与人马座的一次碰撞

The oldest encounter happened about 5.7 billion years ago, and it seems to have triggered a period of star formation around the time the Sun would have been forming.

最古老的碰撞发生在大约57亿年前 它似乎触发了一段恒星形成周期 大约就在太阳形成的时候

Since this was all billions of years ago, proving a direct connection to the Sun is probably impossible.

毕竟这都是数十亿年前的事了 也不可能去证明它与太阳有直接的联系

But this does give astronomers a plausible scenario to explain what could have happened.

但这确实给天文学家提供了一个可行的方案来解释可能发生的事

As Sagittarius sloshed through, its gravity would have stirred up the Milky Way’s huge clouds of gas and dust.

当人马座穿过时 它的引力会搅动银河系巨大的气体云和尘埃

And parts of those clouds would have suddenly become dense enough to collapse into the start of a new star.

这些云的一部分会突然变得非常密集 坍缩成一颗新的恒星

What’s more, since Sagittarius is so much smaller than the Milky Way, the gravity from our galaxy would have stolen some of its gas and dust with every collision.

更重要的是 由于人马座比银河系小得多 我们星系的引力会在每次碰撞中偷走一些气体和尘埃

That means that the Sun—and maybe even the Earth—could be made, at least in part, of material from another galaxy.

这意味着太阳——甚至地球——可能至少有一部分是来自另一个星系的物质所构成的

In other space news, we also found out last week that astronomers have observed a rare and mysterious event called a Fast Blue Optical Transient, or FBOT.

在其他太空新闻中 我们上周还发现天文学家观测到了一种罕见而神秘的现象 称为快速蓝光瞬变现象(Fast Blue Optical Transient 简称FBOT)

That’s just a fancy way of saying that a funny-looking blue spot suddenly appeared in the night sky.

它只是对一个看起来比较滑稽的蓝点突然出现在夜空的一种说法

It wasn’t bright enough to see with your naked eye, but astronomers and their observatories noticed pretty quickly.

它不够明亮 肉眼看不见 但天文学家和他们的天文台很快就注意到了

We’ve detected a handful of these things before, but in a paper published in the Astrophysical Journal Letters on May 26,

我们之前已经发现了一些这样的东西 但是在5月26日发表在《天体物理学杂志通讯》上的一篇论文中

the researchers announced that they were able to study an FBOT using radio waves and X-rays for just the third time.

研究人员宣布他们能够第三次使用无线电波和x射线来研究FBOT

So, uh, what are these things? That’s the next big question.

那么 呃 这些是什么?这是下一个大问题

We first realized these events were in a category of their own in 2014, but observing them is a challenge:

2014年 我们第一次意识到这些事件属于它们自己的类别 但是观测它们是一个挑战:

They reach maximum brightness in only a few days, which makes it hard to coordinate an observing campaign among multiple telescopes.

它们在短短几天内达到最大亮度 这使得在多个望远镜之间的协调观测活动变得很难

They also seem to happen in small, unremarkable galaxies we aren’t really focusing on.

它们似乎也发生在我们没有注意到的不起眼的小星系中

In fact, astronomers didn’t even know about the galaxy this one was in until the burst happened.

事实上 天文学家甚至在爆炸发生之前都不知道这个星系所在的位置

One thing we do know, though, is that FBOTs are powerful.

但我们知道的一点是FBOT非常强大

This new event, for example, accelerated material weighing up to ten percent the Sun’s mass to more than 55% the speed of light.

例如 这个新事件将重达太阳质量10%的物质加速到超过光速的55%

So that’ like accelerating a collection of particles heavier than a hundred Jupiters to around 160 million meters per second.

这就相当于把比100个木星还重的粒子集合加速到每秒1.6亿米

It takes a truly violent event to get so much stuff moving so quickly.

它需要一件非常猛烈的事才能让这么多东西移动得如此之快

And in the new paper, the researchers conclude that the most likely cause of FBOTs is a rare kind of supernova that comes from the explosion of an extra-heavy star.

在这篇新论文中 研究人员得出结论 FBOT最可能的原因是一种罕见的超新星 它是由一颗超重的恒星爆炸产生的

That might explain why we keep seeing these things in tiny galaxies: Dwarf galaxies typically have a higher fraction of hydrogen and helium than their larger counterparts.

这也许可以解释为什么我们一直在小星系中看到这些东西:矮星系通常比大星系含有更高比例的氢和氦

If the galaxy has more hydrogen, so do its stars, and that actually reduces the amount of mass they lose over their lifetime.

如果星系有更多的氢 那么它的恒星也有更多的氢 这实际上减少了它们在生命中失去的质量

So, the end result is a bigger star and a more powerful explosion when it finally dies.

因此 最终的结果是恒星更大 当它最终死亡时 爆炸的威力也更大

As always, it would help to see more FBOTs and gather more evidence, but there’s hope here, too:

和往常一样 这有助于让我们看到更多FBOT并收集更多证据 但也有希望:

While only a few dozen have been confirmed, astronomers suspect that old data probably contains evidence of many more bursts like this.

虽然只有几十个被证实 天文学家怀疑旧的数据可能包含更多类似爆炸的证据

Both these discoveries illustrate the big advantage that specialized tools can offer.

这两个发现都说明了专业工具可以提供的巨大优势

This latest FBOT was first observed by an automated telescope designed to search for supernovas.

这个最新的FBOT首先是由一个搜索超新星的自动望远镜观测到的

And Gaia’s astrometric measurements are like nothing else currently being produced.

而盖亚的天文测量与目前正在进行的任何其他测量都不一样

So, while the super famous Hubble Space Telescope can take some amazing pictures, it can’t do all the work by itself.

所以 虽然超级著名的哈勃太空望远镜可以拍摄一些令人惊叹的照片 但它不能独自完成所有的工作

And fortunately, it doesn’t have to.

幸运的是 它也不需要这样

Thanks for watching this episode of SciShow Space News!

感谢收看本期太空科学秀!

This week’s news is sponsored by The Ridge, the makers of The Ridge Wallet.

本周的新闻由The Ridge赞助 The Ridge钱包的制造商

The wallet is designed to be sleek and light, but also hold everything you need—assuming you need up to a dozen cards plus cash.

这款钱包设计得既光滑又轻便 而且能装下你需要的所有东西——假设你最多需要12张卡外加现金

It comes in more than 30 colors and styles and also comes with a lifetime warranty.

它有30多种颜色和款式 而且有终身保修

If you want to learn more, The Ridge is offering a 45-day test-drive where you can try the wallet and see what you think.

如果你想了解更多信息 Ridge提供了45天的试用体验 你可以试用一下这款钱包 看看感受如何

And if you don’t love it, you can send it back for a full refund.

如果你不喜欢它 也可以全额退款

If you’re interested, you can get 10% off and free worldwide shipping by going to ridge.com/SCISHOW and using the promo code “SCISHOW.”

如果你感兴趣 可以登录ridge.com/SCISHOW并使用优惠码“SCISHOW”获得10%的折扣和全球免费配送

When you support our sponsors, you’re also helping us make more episodes like this one.

支持我们的赞助商 就是在帮助我们制作更多像这样的节目

So thanks for considering it!

所以谢谢你的考虑!