(单词翻译:单击)
On New Year's Day, the New Horizons spacecraft performed the farthest flyby ever, zooming past an object called MU69.
新年当天，新视野号航天器执行了目前为止距离最远的飞近探测，并经过了一个名为MU69的物体。
It's a small, frozen rock way past Neptune, and because it's so cold, it likely hasn't changed much in billions of years.
MU69是一块体积很小的冰冻岩石，曾飞过海王星。而由于其温度极低，所以即便经过数十亿年的时间，也不会有太大变化。
So scientists have been hoping it can teach us about the solar system's early conditions.
所以，科学家希望通过它，我们能了解太阳系早期的情况。
Except, we may have gotten more than we bargained for.
不过，我们得到的信息却不止于此。
For the last few weeks, as the first images of MU69 have trickled in, we've been looking at what we thought was some kind of primordial snowman… but we were wrong.
过去几周里，随着MU69首批图像的流出，我们一直在观察很像是原始雪人的东西，但这东西并非原始雪人。
Last week, NASA released a new picture of MU69, based on images that New Horizons snapped 10 minutes after its closest approach.
上周，美国宇航局发布了MU69的一幅图像。图像来源是新视野号在达到最近点后拍摄了10分钟的图像。
And after some analysis, astronomers discovered that our beloved snowman is actually more like a pair of lumpy pancakes.
经过一番分析后，天文学家发现，我们极为感兴趣的雪人只是一堆波浪起伏的煎饼形状罢了。
We've never seen anything quite like it, and it's throwing astronomers for a loop.
我们从未见过这样的东西，这让天文学家伤透了脑筋。
And it wasn't simple to get this picture of MU69.
而且这幅图像也得之不易。
At this point in the flyby, New Horizons was looking backward into the solar system, and it saw the rock as nothing but a crescent of light.
在飞近探测的这个点上，新视野号的目标是观测太阳系内部。在新视野号的观测中，这个岩石不过是新月而已。
A lot like with a crescent Moon, the unlit part of its body was completely invisible.
跟新月很相似的一点是：其灰暗的部分是完全不可见的。
And the lit part was so faint that the photos had to have long exposures to collect enough light to see much of anything.
而光亮的部分，其光线也很微弱，所以，图像要经过长时间的曝光，才能收集到足够的光线，以看清图像的内容。
But that also meant those images were really blurry, which will happen when you're taking a long-exposure picture while flying by at more than 50,000 kilometers per hour.
但这也意味着这些图像清晰度很低，因为长期曝光的图像会发生这种情况，毕竟飞近探测的速度达到了5万公里/小时以上。
To form this new image, astronomers stacked a bunch of blurry photos together and processed them to get a sharper image.
为了形成这个新图像，天文学家们囤积了许多模糊的图像，将他们一起处理，以获得更为清晰的图像。
Then, they traced around the region where background stars were blotted out, which allowed them to outline the shape of MU69.
随后，他们在该地区大面积寻找蛛丝马迹，寻找背景中恒星得以掩盖的地方，以方便勾勒出MU69的形状。
The team found that largest lobe was extremely flat, and the smaller one looked a little more like a walnut.
该研究组发现，这个巨型的裂片十分平坦，而较小的那一个看起来更像是胡桃。
And that kind of throws a wrench in things, because until now, the early data coming in from MU69 have mostly confirmed our basic ideas about how the solar system formed.
这个发现阻碍了研究的进程，因为目前为止，从MU69得到的早期数据基本上都证实了我们对于太阳系形成方式的想法。
The two lobes, frozen mid-collision, offered pretty solid evidence that, early on, tiny, relatively round planetesimals clumped together to form larger bodies, including the planets.
这2个裂片是在撞击过程中冻结的，他们提供了确凿的证据表明，太阳系初期的时候，一些细小的、形状相对较圆的星子汇聚在了一起，形成了更大的星体，包括行星。
But this flatness thing comes out of left field.
剩下的区域则形成了这种平坦的区域。
We've never seen an object this shape orbiting the Sun.
我们从未见过如此形状的物体环绕太阳。
The closest thing to it might be Saturn's moon Atlas.
与它最近的物体可能是土卫十五。
It's flat too, but it formed under completely different circumstances, in the middle of Saturn's rings, so it doesn't help us understand how MU69 came to be.
它也很扁平，但它是在完全不同的条件下形成的——在土星环的中央，因此它无法帮助我们了解MU69的形成方式。
So far, scientists don't have any strong ideas about what might have flattened these rocks.
目前为止，科学家对于这些岩石是如何变平坦的过程没有太多头绪。
But as more data slowly cross the several billion kilometers between us and New Horizons, we'll continue to learn more.
但随着我们对自己与新视野号这几十亿公里间的信息了解的更多，我们会逐渐解开谜题的。
Whatever hypotheses emerge will almost definitely shake up our ideas about the process that made MU69, and the process that likely made Earth.
无论出现什么假设，基本上都会改变我们对MU69形成过程的理解。而MU69的形成过程很可能也是地球形成的过程。
Objects like this can help researchers understand the past and future of our solar system, but astronomers are also interested in a lot more than that.
与它类似的物体可以帮助天文学家了解太阳系的过去和未来，但天文学家不只是对这一点感兴趣。
On a much more massive scale, they're also decoding our galaxy's past as a way to understand what's in store for it.
从更大的体量上说，科学家将解密太阳系作为一种预测其未来的方式。
We've known since the 1920s that, unlike other galaxies, which are moving away from us, a number of nearby galaxies are moving toward us.
自上世纪20年代以来，我们就知道，太阳系与其他星系不同，因为其他星系是逐渐远离我们的，而太阳系附近的星系却是在朝向我们运动。
They're part of what's called the Local Group and, eventually, the whole thing will merge with other objects to form one massive galaxy.
它们就是本星系群的一部分。最后，本星系群会与其他物体汇聚在一起，形成一个大型星系。
But until now, the details of exactly how and when that will happen have been hard to pin down.
但目前为止，这一天何时发生、怎样发生等细节很难确定。
Then, last week, astronomers announced in the Astrophysical Journal that they had mapped the motion of our two largest neighbors: the Andromeda and Triangulum galaxies.
然后，就在上周，一些天文学家在《天体物理学杂志》发文宣布他们已经绘制出了2个大邻居的移动情况：仙女座星系和三角星系。
Along with the Milky Way, they hold most of the mass in the Local Group, and their pasts and futures are intertwined with ours.
这2个邻居和银河系一起，承载了本星系群的大部分质量。而且，无论是它们的过去还是未来都与我们的过去和未来紧密相连。
So studying them has given scientists the clearest picture yet of the Milky Way's fate, and of its eventual collision with Andromeda.
所以，通过研究这2个邻居，科学家就能得到银河系命运的清晰图谱，以及它与仙女座星系最终的撞击情况。
The researchers used data from the European Space Agency's Gaia space telescope, which is about 1.5 million kilometers from Earth.
研究人员还使用了欧洲太空总署全天球天体测量干涉仪（Gaia）的数据，这些数据来源于距离地球150万公里的地方。
Gaia was made to create a 3D map of stars that are mostly in our galaxy.
研制Gaia是为了创造出太阳系内各恒星的3D图谱。
But it's actually powerful enough to peek inside other nearby galaxies, too.
但由于其十分强大，所以足以窥见临近星系内部的情况。
For this study, the researchers identified thousands of individual stars in these galaxies, then collected really precise data on their positions and motions,
在这项研究中，天文学家确定了这些星系中的上千颗单独的恒星，然后收集了有关它们位置和移动情况的准确数据。
which, by the way, is not easy to do: On the plane of the sky, any movement a few million light-years away is miniscule.
这里顺便说一句，这过程十分艰辛，因为在天空中，距离我们几百万光年的物体，即便其移动了，在我们看来也是微乎其微的移动。
But it's worth it. The useful thing about individual stars is that they can give us a detailed look at a galaxy's structure and reveal how stars move around its axis.
但也值了。因为单独恒星提供的有用信息让我们可以从细节角度了解一个星系的结构，以及其轴线附近恒星的移动方式。
The scientists were able to use the data to trace the paths of Andromeda and Triangulum for billions of years into the past and future.
科学家可以通过这些数据来追踪仙女座星系和三角星系的路径，从而窥探其过去和未来。
And they found a few interesting things.
在这个过程中，他们发现了一些有意思的事情。
For one, it looks like we're actually not poised for a head-on collision with Andromeda, as we used to think.
其一，我们似乎并没有从一开始就确定要和仙女座来个正面撞击，这与我们过去的想法相反。
When the two galaxies do have their run-in, it will be more of a shoulder bump, where they hit each other from the side.
就算这2个星系有撞击的趋势，也顶多是擦肩而过，侧面会有摩擦。
That doesn't mean it will be pretty though, Andromeda is still headed for us at around 400,000 kilometers per hour, but it won't be the smashup we expected.
虽然摩擦的程度不是很确定，毕竟仙女座依然在以近40公里/小时的速度向我们移动，但至少不是我们以前所想的那种剧烈撞击。
The new findings also push back the date of that fateful collision to about 4.5 billion years from now.
该研究的新发现成果也将撞击的时间向后推了推，推到了距今45亿年的时候。
That's around 600 million years later than existing models.
这比现有模型延后了近6000万年的时间。
These results show that Gaia has lots of potential for exploring beyond the galaxy.
这些结果表明，Gaia有很大的潜力，可以探索到太阳系之外的地方。
And the better we understand these neighbors, the more we can figure out about the structure and evolution of galaxies in general.
而我们对邻居们了解的越多，我们就越有可能知道各星系总体上的结构和进化过程。
Astronomy research can often work like a catapult: The farther we go back, the farther we can reach into the future.
天文学研究通常发射弹弓的机理一样：对过去探究的越透彻，就越有利于窥见未来。
And from the edges of our solar system to well beyond the Milky Way, astronomers are using that strategy to make sense of the universe.
从太阳系边缘到银河系之外，天文学家正在通过这样的策略来了解宇宙。
Thanks for watching this episode of SciShow Space News.
感谢收看本期的《太空科学秀》。
And a special, spacious thanks to SR Foxley, our Patreon President of Space.
尤其要感谢我们空间站的会长弗克利。
Scientists are learning new things about the universe literally every week, and we wouldn't be able to keep up with covering it without your generous support.
每一周，科学家都对宇宙有了新的了解，如果没有粉丝们的支持，我们是无法持续跟进的。
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And thank you!
谢谢大家！
