Yes, there is really 'diamond rain' on Uranus and Neptune

确实如此，天王星和海王星上真的有钻石雨。

The ice giants Uranus and Neptune don't get nearly enough press; all the attention goes to their larger siblings, mighty Jupiter and magnificent Saturn.

冰巨人天王星和海王星没有得到足够的关注；所有的注意力都集中到了比它们年龄稍长的兄弟姐妹--强大的木星和宏伟的土星上。

At first glance, Uranus and Neptune are just bland, boring balls of uninteresting molecules. But hiding beneath the outer layers of those worlds, there may be something spectacular: a constant rain of diamonds.

乍一看，天王星和海王星只是平淡无奇，不会引人注目的无趣的球体。但是，在其外层之下可能隐藏着一些由源源不断的钻石雨形成的壮丽景象。

Related: Icy planets' diamond rain created in laser laboratory

相关报道：激光实验室制造的冰行星钻石雨

"ice giants" may conjure the image of a Tolkien-esque creature, but it's the name astronomers use to categorize the outermost planets of the solar system, Uranus and Neptune.

“冰巨人”可能让人联想到托尔金式的生物形象，但实际上 它是天文学家用来分类太阳系最外层行星天王星和海王星的名字。

Confusingly, though, the name has nothing to do with ice in the sense you would normally recognize it — as in, say, ice cubes in your drink. The distinction comes from what these planets are made of. The gas giants of the system, Jupiter and Saturn, are made almost entirely of gas: hydrogen and helium. It's through the rapid accretion of those elements that these huge planets managed to swell to their current size.

然而，令人困惑的是，这个名字与你通常会认识到的冰毫无联系--比如，你喝饮料中的放的冰块。区别在于构成这些行星的主要成分。太阳系的气态巨行星木星和土星几乎全部氢气和氦气构成的。正是通过这些元素的快速吸积，这些巨大的行星才得以膨胀到现在的大小。

In contrast, Uranus and Neptune are made mostly of water, ammonia and methane. Astronomers commonly call these molecules "ices," but there really isn't a good reason for it, except that when the planets first formed, those elements were likely in solid form.

相反，天王星和海王星主要由水，氨和甲烷构成。天文学家通常称这些分子为“冰”，但实际上并没有一个好的理由，除非行星最初形成时，这些元素很可能是固态的。

Deep beneath the green or blue cloud tops of Uranus and Neptune, there's a lot of water, ammonia and methane. But these ice giants likely have rocky cores surrounded by elements that are probably compressed into exotic quantum states. At some point, that quantum weirdness transitions into a super-pressurized "soup" that generally thins out the closer you get to the surface.

在天王星和海王星的绿色或蓝色云顶之下，有大量的水，氨和甲烷。但是这些冰巨星很可能有岩石核心，周围的元素很可能被压缩成奇异的量子态。在某种程度上，量子会异变成一种超高压的“汤”，通常越接近表面就越稀薄。

But truth be told, we don't know a lot about the interiors of the ice giants. The last time we got close-up data of those two worlds was three decades ago, when Voyager 2 whizzed by in its historic mission.

但说实话，我们对冰巨人的内部构造知之甚少。我们上一次获得这两个世界的特写数据是在30年前，当时正好是旅行者2号在执行其历史性任务时呼啸而过。

Since then, Jupiter and Saturn have played host to multiple orbiting probes, yet our views of Uranus and Neptune have been limited to telescope observations.

从那时起，木星和土星就有了多个轨道探测器，但我们对天王星和海王星的观察还一直局限于望远镜观测。

To try to understand what's inside those planets, astronomers and planetary scientists have to take that meager data and combine it with laboratory experiments that try to replicate the conditions of those planets' interiors. Plus, they use some good old-fashioned math — a lot of it. Mathematical modeling helps astronomers understand what's happening in a given situation based on limited data.

为了试图了解这些行星内部的情况，天文学家和行星科学家必须将这些贫乏的数据与在实验室中试着复制这些行星内部状况做的实验相结合。另外，他们使用了很多良好的传统的数学。基于有限的数据，数学建模可以帮助天文学家理解在给定的情况下发生了什么。

And it's through that combination of mathematical modeling and laboratory experiments that we realized Uranus and Neptune might have so-called diamond rain.

通过数学建模和实验室实验的结合，我们意识到天王星和海王星可能存在所谓的钻石雨。

Related: Amazing photos of monster storm in Saturn's atmosphere

相关报道：惊人照片——土星大气层中的怪兽风暴。

The idea of diamond rain was first proposed before the Voyager 2 mission which launched in 1977. The reasoning was pretty simple: We know what Uranus and Neptune are made of, and we know that stuff gets hotter and denser the deeper into a planet you go. The mathematical modeling helps fill in the details, like that the innermost regions of the mantles of these planets likely have temperatures somewhere around 7,000 kelvins (12,140 degrees Fahrenheit, or 6,727 degrees Celsius) and pressures 6 million times that of Earth's atmosphere.

钻石雨这一观点是在1977年旅行者2号任务发射之前首次提出的。原因很简单：我们知道天王星和海王星是由什么组成的，我们也知道越深入到一颗行星的，其内部的物质就温度就会越高，密度也越高。数学建模有助于填补细节，比如这些行星地幔最内部的温度可能在7000开尔文（12140华氏度，或6727摄氏度）左右，其压力是地球大气层的600万倍。

Those same models tell us that the outermost layers of the mantles are somewhat cooler — 2,000 K (3,140 F or 1,727 C — and somewhat less intensely pressurized (200,000 times Earth's atmospheric pressure). And so, it's natural to ask: What happens to water, ammonia and methane at those kinds of temperatures and pressures?

同样的模型告诉我们，地幔的最外层温度要低一些--2000 K（3140华氏度或1727摄氏度），压力也要小一些（地球大气压的20万倍）。因此，自然而然，我们会有这样的疑惑：在这样的温度和压力下，水，氨和甲烷会发生什么？

With methane, in particular, the intense pressures can break the molecule apart, releasing the carbon. The carbon then finds its brethren, forming long chains. The long chains then squeeze together to form crystalline patterns like diamonds.

特别是甲烷，高压能使分子分裂，释放出碳。然后碳找到其同类物质，形成长链。然后长链挤压在一起形成像钻石一样的水晶图案。

The dense diamond formations then drop through the layers of the mantle until it gets too hot, where they vaporize and float back up and repeat the cycle — hence the term "diamond rain."

然后，密度极高的钻石层穿过地幔层，直到地幔变得太热，在那里它们蒸发并漂浮起来，重复这个循环--因此有了“钻石雨”这个术语。

The best way to validate this idea would be to send a spacecraft toUranus or Neptune. That won't be an option anytime soon, so we have to go with the second-best way: laboratory experiments.

验证这一想法的最好的方式是往天王星或海王星上发射一艘太空船。但这在短期内是不可能的，所以我们不得不采用第二好的方法：实验室做类似实验。

On Earth, we can shoot powerful lasers at targets to very briefly replicate the temperatures and pressures found inside the ice giants. One experiment with polystyrene (aka Styrofoam) was able to make nano-sized diamonds. No, Uranus and Neptune don't contain vast quantities of polystyrene, but the plastic was much easier than methane to handle in the laboratory and, presumably, behaves very similarly.

在地球上，我们可以向目标发射强大的激光，以非常短暂地复制在冰巨人内部发现的温度和压力。用聚苯乙烯（又名聚苯乙烯泡沫塑料）做的一个实验能够制造出纳米尺寸的钻石。不，天王星和海王星并不含有大量的聚苯乙烯，但在实验室中，塑料比甲烷更容易处理，而且可能表现得非常相似。

Also, Uranus and Neptune can keep up those pressures for a lot longer than a laboratory laser, so the diamonds could presumably grow to be a lot larger than nano-sized.

此外，天王星和海王星能够维持这些压力的时间比实验室的激光要长得多，所以钻石可能会生长得比纳米尺寸大得多。

The end result? Based on everything we know about the composition of the ice giants, their internal structures, results from laboratory experiments and our mathematical modeling, diamond rain is a very real thing.

这难道就是最终的结果吗？基于我们所知道的关于冰巨人的组成，它们的内部结构，实验室实验的结果以及我们的数学建模，钻石雨是一个非常真实的东西。

Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of "Ask a Spaceman" and "Space Radio," and author of "How to Die in Space."

保罗·M·萨特（Paul M.Sutter）是纽约州立大学石溪分校和Flatiron Institute的天体物理学家，《问太空人》和《太空电台》的主持人，《如何在太空中死去》的作者。

Learn more by listening to the "Ask A Spaceman" podcast, available on iTunes and askaspaceman.com. Ask your own question on Twitter using #AskASpaceman or by following Paul @PaulMattSutter and facebook.com/PaulMattSutter.

请收听iTunes和askaspaceman.com上的“问太空人”播客，了解更多信息。你可以在推特上用#AskASpaceman或者关注Paul @PaulMattSutter和facebook.com/PaulMattSutter来提问。