评论
打印
From snazzy banded agates to volcanic elephants, there are some pretty weird rocks out there.
无论是炫目的带状玛瑙，还是火山象，宇宙里到处都是五花八门的石块。
But the weirdest ones geologists find might be those that fall from space.
但地质学家发现的最为奇异的当属从宇宙落下来的石块了。
And one called the Hypatia stone could be, the strangest of them all.
而在这些石块中最奇异的当属希帕提娅石了。
In fact, all signs currently suggest that this rock's origin story is older than the solar system itself!
不瞒你们说，目前的所有迹象都表明：希帕提娅石的年纪比太阳系还要大！
And if it's not… well, we're going to have to rethink what we know about our cosmic neighborhood.
如果事实并非如此的话，那……我们大概是对自己的邻居有什么误解吧。
The Hypatia stone was found in 1996 by a geologist in the southwest Egyptian Sahara.
希帕提娅石是1996年埃及撒哈拉沙漠西南部某地质学家发现的。
It's named after the first female astronomer and mathematician who managed to make the history books.
它是以第一位女性天文学家兼数学家命名的，因为是此人将这石块记载在了史册当中。
The stone was discovered in fragments no bigger than a centimeter across, and in total, the pieces added up to a volume only about 20 cubic centimeters.
希帕提娅石被发现的时候，是呈碎片形态的，身长不超过1cm。所有碎片加起来的体积只有20立方厘米。
Technically, it isn't considered a meteorite, because the Meteoritical Society requires 20% of a rock's original mass to be present to earn that title.
从技术上来讲，希帕提娅石还不算是陨石，因为根据国际陨石学会的要求，原始质量达到至少20%才能算是陨石。
And scientists have chipped this thing apart and sent pieces to so many labs that it no longer fits the bill.
而且科学家将希帕提娅石削成了很多碎片，送往了很多实验室，所以希帕提娅石就更不符合要求了。
But it's definitely from space.
但有一点毫无疑问：希帕提娅石来自宇宙。
When its extraterrestrial origins were confirmed in 2013, scientists assumed it was the very first comet nucleus, or the rocky, central part of a comet, to be found on Earth.
2013年，人类确定了希帕提娅石的行星影区后，科学家认为它是地球上发现的宇宙里的第一个彗核。所谓彗核，就是彗星的核心部分。
But its story is a bit more complicated. And interesting.
不过，事情并没这么简单，不过，倒是颇有意思。
First, exactly when the stone struck our planet is hard to pin down.
首先，希帕提娅石撞击地球的时间点很难确定。
It was found in an area of the Sahara full of these special rocks called Libyan Desert Glass, which are believed to have been created by a meteorite impact 28-ish million years ago.
希帕提娅石是在撒哈拉沙漠里的利比亚沙漠玻璃中被发现的，该地区到处都是这种奇异的石块。有人认为，该地区正是由2800万年前陨石的撞击所形成的。
But the relationship between the Hypatia stone and this glass is far from certain.
但希帕提娅石和利比亚沙漠玻璃的关系依然没有确定。
We're also not positive how big this rock was when it initially entered Earth's atmosphere.
同样不确定的还有希帕提娅石刚刚进入地球大气层时候的体积。
Based on its amount of a certain type of neon, we think it couldn't have been more than several meters in diameter.
基于其中某种氖元素的含量，我们认为，希帕提娅石当时的直径一定不可能超过几米。
Or, if it were bigger, the Hypatia stone itself had to have come from the upper few meters.
或者，即便希帕提娅石的直径超过几米了，肯定也是上面的那几米。
These basic details are important to figure out, but what's really strange about the Hypatia stone is what researchers discovered once they started analyzing its composition.
这些基本信息很重要，但希帕提娅石真正的奇异之处在于科学家在分析其组成时所发现的情况。
Because from what we can tell, Hypatia's chemical makeup isn't just out of this world.
因为根据人类目前的所知，希帕提娅石的化学组成根本就不存在于我们的世界里。
It's out of the entire solar system! See, everything in our neighborhood formed out of the same cloud of dust and gas.
反正太阳系里没有的！毕竟太阳系里的所有事物都是由同样的灰尘和气体云组成的。
And since astronomers believe that the cloud was relatively homogenous, the rocky bits that formed should all, on the whole, have roughly the same chemical makeup.
而且由于天文学家认为这种云是相对同质的，所以其组成的希帕提娅石碎片，其组成也应该差不多。
But in 2015, scientists revealed that the Hypatia stone is different.
但2015年的时候，科学家发现希帕提娅石组成与众不同。
It has a composition unlike any other solar system object studied in a lab.
其组成跟我们研究过的太阳系里的其他事物都不相同。
For example, its amount of the isotope nitrogen-15, a type of nitrogen with an extra neutron, was way off for it to be from a standard comet.
比如，其氮同位素氮-15（比氮多一个中子的同位素）的含量根本不符合彗星里氮-15的含量。
Astronomers also found a type of xenon that's created when one iodine isotope, one that predates the solar system, undergoes radioactive decay.
天文学家还发现了一种氙，这种氙是在一种碘的同位素发生放射性衰变时形成的。这种碘的同位素年龄也比太阳系要大。
So something about this thing totally isn't normal.
所以，希帕提娅石肯定有什么地方与众不同。
And this year, we got an even deeper analysis.
今年，我们进行了更深一步的分析。
In February 2018, a team of astronomers announced that they'd identified two separate, yet intermingled, matrices in the Hypatia stone, kinda like finding two different batters in the same cake.
2018年2月，一组天文学家宣布他们在希帕提娅石中发现了2种各自独立却又相互混合的基质，这就好像在同一个蛋糕里发现了2种不同的面粉原料一样。
The matrices themselves had to have formed when the solar system did, because Hypatia needed a cloud of dense interstellar dust to form.
这些基质本身形成的时间点肯定和太阳系一样，因为希帕提娅石形成的前提是有密度很高的星际尘埃云。
But they had the opposite composition of carbon and silicon that common meteorites do.
但它们碳和硅元素的组成跟正常的陨石正好相反。
The ones we normally see, called chondritic meteorites, are low in carbon and high in silicon, but Hypatia has lots of carbon and basically no silicon.
通常情况下，我们见到的陨石，比如球状陨石，其碳含量很低，硅含量很高，但希帕提娅石的碳含量很高，硅含量却很低。
So again, not normal.
这一点又是不太正常了。
But what was even more surprising about this analysis is that one of those matrices was also chock-full of deposits, or inclusions.
但分析结果中更令人惊奇的是：其中一种基质中充满了沉积物，也就是夹杂物。
And each of them likely existed before the entire solar system!
而且每种沉积物都是在太阳系形成之前就存在了的！
This includes moissanite grains, which are commonly a small part of some meteorites, but are considered to be mostly pre-solar.
其中就包括碳硅石颗粒，这种颗粒是一些陨石中常见的小部分组成物质，但却是普遍认为存在于太阳系形成之前的。
They also found a nugget of pure metallic aluminum in Hypatia, which is super rare in solar system rocks.
他们在希帕提娅石中还发现了一部分金属铝，这是太阳系陨石中极少见的物质。
And there were also a lot of these organic molecules called polycyclic aromatic hydrocarbons, or PAHs, which are a big part of interstellar dust.
其中还有很多的有机颗粒——多环芳烃(PAH)，这种物质在星际尘埃中占有很大的百分比。
PAHs are also inside certain comets and asteroids, so finding them in the Hypatia stone wasn't unusual, but the abundance of them was.
多环芳烃也是一些彗星和小行星的组成成分，所以在希帕提娅石中发现多环芳烃并不奇怪，但发现很多的话，就不太正常了。
Conveniently, these PAHs were also a big reason we're able to study the stone today.
所以，自然低，多环芳烃也成了我们当前研究希帕提娅石的一个重要原因。
Many of the them were turned into a crust of tiny diamonds, likely when Hypatia crashed into the Earth,
很多多环芳烃最后都变成了像细小金刚钻一样的外表皮，比如在希帕提娅石落入地球的过程中，
and they protected and preserved the inside of the rock for millions of years.
数百万年来，起到了保护内核的作用。
But that doesn't explain where they came from.
不过，这并不能解释它从何而来。
And there were other compounds found that haven't been observed in any studied space rock, too.
希帕提娅石中还有一些化合物是我们在实验室中未曾发现过的。
So the Hypatia stone is still completely unique. At least as far as we know.
所以，希帕提娅石真的是与众不同，至少在我们所了解的陨石中算是独树一帜。
Although it's a pretty compelling case, we'll still need further analysis of certain isotopes before we can definitively say that parts of this rock existed before the Sun.
虽然希帕提娅石万众瞩目，但我们依然需要进一步研究一些同位素后才能确认其部分组成是否是在太阳形成前就存在了。
But the exciting news is, the authors of that 2018 paper hope to get that research out ASAP, so we'll keep you updated.
但令人激动的消息是：2018年这篇论文的几位作者希望能尽快研究出结果，所以我们会持续关注并给大家传递消息哦。
So, even if Hypatia turns out not to be pre-solar, that might be even weirder.
所以，即便希帕提娅石不是在太阳之前出现的，可能就更加奇怪了。
That would imply that the early solar system wasn't homogeneous after all, despite the generally accepted view.
如果是这样，就表明，太阳系初期根本就不是同质的，虽然目前普遍认可的说法是同质。
So we'd have to change the way we think about our neighborhood's history.
所以如果是这样的话，我们对于整个太阳系历史的看法就要彻底颠覆了。
Based on what we know so far, astronomers can at least tell that the stone had to have formed in a super cold environment, one below about -200°C.
根据目前了解的情况，天文学家至少可以判断出一点：希帕提娅石是在极度低温的环境里形成的，至少要低于零下200摄氏度。
So if it is from around here after all, that likely means Hypatia had to have formed out in the Kuiper Belt where Pluto lives, or even farther away, like in the distant, mysterious Oort cloud.
所以如果希帕提娅石是在太阳系里形成的，那这很可能表明：希帕提娅石是在凯伯带形成的，而凯伯带正是冥王星所在的地方；如果再往远一点推，可能是在神秘而又遥远的奥尔特云处形成的。
We don't actually know a lot about the composition of all the bodies that far out there, so it could totally turn out that there are other Hypatia-like space rocks.
对于那附近的星体和物质，我们了解的不是很多，所以我们最后得到的结果可能是：那附近有其他像希帕提娅石一样的石块。
Mosty, all this means means we just have to keep looking.
不管怎样，我们都只能继续保持关注了。
But no matter what the answer to this mystery is, we're gonna learn something cool.
但无论谜题的答案是什么，我们都会了解到不可思议的新消息。
Thanks for watching this episode of SciShow Space!
感谢收看本期的《太空科学秀》！
If you'd like to keep exploring the mysteries of the universe with us, and learning some cool stuff along the way, you can go to youtube.com/scishowspace and subscribe.
如果您想和我们一起探索宇宙的奥秘同时了解一些很酷的知识的话，不妨订阅youtube.com/scishowspace哦。
