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The solar system, it turns out, is full of volcanoes, but not all of them spew or ooze liquid rock, like you might tend to picture.
我们发现太阳系里到处都是火山，但并非所有火山都会喷射出液态熔岩，虽然我们可能会这样想象。
Where it's cold enough, we also see evidence of cryovolcanoes that spit out slushy ices.
如果气温足够低，还会发现冰火山的痕迹，这种火山会喷射出融冰。
So far, we've found them on several gas giant moons and on Pluto.
目前为止，我们在几颗气体巨星和冥王星上发现了冰火山的痕迹。
And we've even found one in the asteroid belt, on the dwarf planet Ceres.
我们甚至在小行星带矮行星的谷神星里发现了一个冰火山。
Now, scientists reported this week in Nature Astronomy that they may have discovered up to 31 more cryovolcano remnants on Ceres.
本周，科学家在《自然天文学》上发表报告称，他们可能在谷神星上又发现了31个冰火山的残留物。
It's a volcano wonderland. In 2015, NASA's Dawn spacecraft arrived at Ceres, and it's been mapping and studying the object's surface ever since.
这里简直是火山仙境。2015年，美国宇航局的飞行器Dawn抵达了谷神星，然后开始对谷神星表面进行绘图和研究。
During its first year, Dawn found one cryovolcano that formed the mountain Ahuna Mons.
第一年，Dawn发现了一个冰火山，也就是孤山。
It's probably less than 240 million years old, which isn't that ancient when you're talking about space volcanoes.
孤山年龄应该不到2.4亿年，就宇宙里的所有火山而言，这座火山不算很久远的了。
To really understand Ceres's history, researchers need to study older volcanoes.
要真正了解谷神星的历史，研究人员需要研究年龄更大的火山。
But it's been harder to find any, because the material they're made out of sags and flattens over time.
但找年龄更大的冰火山是难上加难，因为冰火山的组成物质会随着时间的推移而逐渐下垂，继而完全变平。
At least, that's what astronomers hypothesized.
至少在天文学家的假设里是这样的。
To confirm that, the team analyzed images of Ceres's surface, looking for large structures that might be flattened-out former cryovolcanoes, or, as they call them, viscously relaxed domes.
为了证实这一点，该研究小组分析了谷神星表面的图像，搜寻体型较大的结构，因为这样的结构在平坦之前可能是冰火山，就像似散不散的拱形结构一样。
And they found a ton! Including Ahuna Mons, the team spotted a whopping 32 candidates.
结果就是他们发现了巨多这样的机构。包括孤山在内，他们总共发现了32个可能曾是冰火山的结构，数量可谓十分庞大了。
Next, they used Dawn's camera to estimate the domes's heights.
然后，他们通过Dawn的摄影机估测了这种拱形结构的高度。
For 10 of the 32 structures, they couldn't get clear enough data, so they were excluded from the analysis.
32个拱形结构中，有10个的数据收集的不够，所以这10个没有用作分析对象。
But the rest were all over 1 kilometer tall.
剩下的22个结构，高度都超过了1000米。
Based on a set of assumptions, like how large the domes would have been when they started out, and how much ice they contain, the team estimated the ages of these domes.
根据一系列假设，比如这些拱形结构刚开始的时候有多大以及它们冰的含量，该研究组估测了这些拱形结构的年龄。
This time, they were able to date all but one.
这一次，它们可以估测出所有拱形结构的年龄，而非其中一个。
They found that most of the structures were between 2 and 700 million years old, but a couple were over 2 billion years old.
他们发现，大多数拱形结构的年龄都在2年-7亿年间，但一些的年龄却超过了20亿年。
This all suggests that, over the last billion years, Ceres got a new cryovolcano every 50 million years or so on average.
这些都表明，在过去10亿年的时间里，谷神星大概每5000万年左右就会生成一个新的冰火山。
Besides teaching us more about Ceres's history, this study also supported the fact that cryovolcanoes are really different from the hot, lava-spewing mountains on Earth.
除了能让我们更加了解谷神星的历史之外，该研究还证明了一个事实的正确性，即冰火山跟地球上那种喷射火热岩浆的火山不同。
For one, the icy magma on Ceres may originate in the dwarf planet's crust, not in any sort of mantle like we see on terrestrial planets.
一方面是因为：谷神星上冰冷的演讲可能是从矮行星的地壳中来，不是我们在类地行星中看到的地幔中来的。
Ceres is also a lot less active. This new study found that the total amount of matter put out by its cryovolcanoes is between 1000 and 100,000 times less than that of the inner planets and the Moon.
而且谷神星的活跃度也不是很高。这项新研究发现，冰火山释放出的物质总量是内行星和卫星的1000-10万倍。
Even if you account for surface area, terrestrial volcanic activity is still an order of magnitude higher.
即便算上地表区域，地球上的火山活动依然量级更高。
This could mean that all cryovolcanic bodies, including places like Pluto and Europa, have similarly low activity, but we'll need more data to know for sure.
这可能意味着所有的冰火山，包括冥王星和木卫二这样地方的冰火山，活跃程度都较低，不过我们需要更多的数据才能确定。
Still, any day where you find a bunch of new volcanoes in the asteroid belt is a pretty good day.
不过，在小行星带发现新火山就是好事儿。
Without a telescope or a good pair of binoculars, you probably won't be able to see Ceres from Earth.
如果没有单筒望远镜和双筒望远镜，很可能就无法从地球上观测到谷神星。
But if you look up on a clear night, you might see a light zooming across the sky for just a few seconds.
但如果在晴朗的夜空观测，可能会在短短几秒里看到天空中快速闪过一道光。
It's not a meteor, and it's probably not a UFO.
这不是流星，很有可能也不是不明飞行物，
Instead, it's what's called a satellite flare: a satellite unintentionally catching the light of the Sun and bouncing it down to you.
而是卫星闪光现象，即某颗卫星无意中捕捉到了日光，然后弹射回地球。
The brightest of these are called Iridium flares, but you'll only be able to see them easily for a little while longer.
其中最亮的要属铱星闪光了，不过，铱星闪光的持续时间也没长多久。
So consider this your heads-up. These flares started around 1997, and they come from a group of Low-Earth orbit communications satellites.
所以这也可以算是给我们的提示。卫星闪光现象是1997年左右发现的，这种闪光现象来自于一组低轨通信卫星。
They're controlled by Iridium Communications Inc., hence the name.
低轨通信卫星是由铱卫星公司控制的，也得名于此。
They're not actually made of iridium or anything.
低轨通信卫星其实不是由铱或者类似的东西组成的。
The flares come from sunlight bouncing off the three silver-coated antennae on each satellite.
这种闪光现象出现是因为日光从每颗卫星上三条镀银的天线弹射了回来。
If the angle is just right, they're bright enough to outshine Venus, and even to be visible during the day.
如果角度合适，其亮度就会超过金星，甚至在白天也看得见。
But Iridium's network of 66 satellites is being replaced right now, with a fleet of 75 smaller ones.
但铱卫星公司网络中的66颗卫星现在已经都被换成了75颗稍小一些的卫星。
These new ones aren't the same shape, so they won't produce any flares.
这些小卫星形状不一，所以不会发生闪光现象。
As of July 2018, there have been seven successful launches to install new, flare-less satellites, and the eighth and final launch is scheduled for November.
截止到2018年7月为止，我们已经7次成功发射并安装了不会发生闪光现象的新卫星，第8次也就是最后一次定于11月进行。
With the new guard coming in, some of the old satellites have already begun de-orbiting, and they will be spiraling down until they're burned up by the Earth's atmosphere.
后继有“星”了，所以一些旧卫星也已经开始脱轨，旧卫星会盘旋向下，直到在地球的大气层中烧尽。
But they won't fall out of the sky all at once.
不过，旧卫星不会一次性在天空中散落。
The different satellites all have their own paths to destruction, and for some of them, that process could take up to 20 years.
不同的卫星各有自己消亡的方式，有些卫星要20年才能完成这一过程。
So while the number of Iridium flares will drop drastically in the next year or so, you might manage to catch one every once in a while.
所以，虽然大概明年的时候，铱星闪光的次数会急剧减少，但还是偶尔看得见的。
It will just be much harder. I remember when I was a teen, my dad took me out into the nighttime to be like, there's the new iridium satellites, and he timed it so that we could watch it together cuz he's a big nerd.
只是难度大了一些。我记得我还是个孩子的时候，我的父亲就曾晚上带我出去看新的低轨通信卫星。他一板一眼地，还给闪光计时，这样我们就能一起看了。
Today, since the satellites' orbits are actively controlled, it's really easy to calculate when and where you need to be to see a flare, but that will change soon.
如今，对低轨通信卫星轨道的控制更为活跃了，可以很容易地计算何时何地可以看到闪光，不过这种情况很快就会发生变化了。
The good news for sky-watchers is that, even once the first Iridium satellites are gone, other satellite flares will still be out there.
不过，喜欢看夜空的人也有好消息，那就是：即便第一批低轨通信卫星脱轨了，其他卫星也会发出可以观测到的闪光。
They're just not as spectacular. And while you and I might be a little sad about that, at least one group of people will be happy: astronomers.
只是频率没那么高了。虽然对于这件事情，咱们都会有些许的失落，但至少有一群人是开心的，那就是天文学家。
Since Iridium flares are so bright, they tend to turn up as annoying streaks in study images.
既然铱星闪光如此明亮，那就会在天文学家研究图像的时候出现不请自来的条纹。
So at least somebody's happy about these satellites getting destroyed by the friction of the atmosphere.
所以，虽然铱卫星会因大气层的摩擦而消失，但至少对有些人来说是好事。
If you're interested in checking out the last predictable Iridium flares, the company has some resources to help you out, and we'll leave a link to them in the description.
如果大家想要了解上一次可预测的铱星闪光是什么时候，铱卫星公司有资源可以帮助大家，大家可以在节目的描述里找到链接。
They even have a bit of a social media campaign about it.
该公司甚至在社交媒体上还有一定的宣传。
It's called #Flarewell, because they just, I guess they had to do that.
话题是#Flarewell，我猜是想给大家一个交代吧。
Thanks for watching this episode of SciShow Space News!
感谢收看本期的《太空科学秀》！
We've got a new piece of merch: These SciShow lab coats which you might recognize if you watch SciShow Quiz Show.
还有福利要放松哦，就是这些《太空科学秀》实验室的服装，如果大家经常观看我们节目智力问答环节的话，就应该能认出来。
But there's only a limited number of them, cuz we found them in a warehouse, so if you want to look fancy in the lab, and show your support for SciShow, head on over to dftba.com/scishow right now to pick one up!
不过数量有限，因为我们是在一个仓库里发现的。所以如果大家想让自己在实验室里看起来很酷的话，如果大家想支持我们节目的话，就去dftba.com/scishow领取吧！
It's got the normal pockets, and then it's got this pocket so that you can get your pocket, inside pocket, without going like this. It goes like that.
这件衣服的口袋就是普通的版型，不过还要先通过这个口袋，才能进那个口袋，这是口袋套口袋的结构啦。
