(单词翻译:单击)
Ever wonder what seasons are like on other planets?
你想知道其他星球上的季节是怎样的吗？
Do you ever get tired of having to switch out your snow pants for swim trunks?
你是否厌倦了用泳裤换掉棉裤？
Well, if you're tired of dealing with Earth's predictable seasons,
如果你厌倦了应对地球上可预测的季节，
many planets in our universe present other options.
宇宙的很多行星会给你其他选择。
For example, astronomers are pondering a recently discovered planet called Kepler 413b,
比如，天文学家正在考虑最近发现的一颗叫做开普勒413b的行星，
that they think might have Game of Thrones-ike seasons.
他们认为它的季节就像《权力的游戏》一样。
Yes, much like Westeros, it has seasons of wildly varying length,
没错，它和维斯特洛大陆很像，季节变化很大，
moving from summer to winter seemingly without warning,
从夏季到冬季似乎没有任何预兆，
which from a wardrobe perspective sounds like a huge hassle.
这对衣柜来说像是个巨大的麻烦。
But how do scientists know what seasons are like there?
但是科学家们如何知道那里的季节是什么样的呢？
The answer comes down to a trait that varies from planet to planet all across the universe.
答案归结于一种不同于整个宇宙行星的特征。
Planets get their seasons, if they have them, from their axial tilt,
行星如果有季节的话，是因为轴倾角，
that jaunty little angle at which the poles tilt relative to the orbital plane.
它是两极相对于轨道面倾斜的小角度。
Earth, for example, sits at 23.5 degrees as it orbits the sun.
以地球为例，它在围绕太阳旋转时，轴倾角是23.5度。
This tilt, or obliquity means that for part of our 365-day orbit,
这种倾斜意味着在我们365天的轨道周期中，
sunlight strikes the northern hemisphere more directly creating summer,
阳光直射北半球创造了夏季，
while it's winter in the southern hemisphere.
而此时的南半球是冬季。
And as we move through our orbit, the whole thing is of course reversed,
而当我们在轨道上移动时，整个过程反了过来，
and the sun then reaches the northern hemisphere at a more oblique angle creating winter.
然后太阳以更加倾斜的角度照射北半球，创造了冬季。
The result of the whole cycle is four roughly equal seasons each lasting about 90 days.
整个周期的结果是四个大致相同的季节，每个季节持续约90天。
But imagine the alternatives to this scenario,
但想象一下这种情形的替代方案，
like if a planet had no tilt at all or a huge tilt or a tilt that changed over time.
比如随着时间的推移，行星没有倾斜、倾斜严重或随着时间倾斜。
As it happens, you can find examples of these extremes within our own solar system.
当这种情况发生时，你可以在我们的太阳系里找到这些极端的例子。
Mercury, Venus, and Jupiter, for example, have zero or very little tilt and thus no seasons.
例如，水星、金星和木星的倾斜角为零或极小，因此没有季节。
Mars, Saturn and Neptune meanwhile have tilts like ours plus or minus a few degrees,
火星，土星和海王星比我们的倾斜角大几度或小几度，
creating even seasons from year to year.
年复一年地产生季节，
And don't get me started on Uranus.
别让我提天王星。
It's tilted a full 98 degrees, basically lying on its side and rolling around the sun.
它倾斜了整整98度，基本上是躺着绕太阳转。
This means that one pole is pointed directly at the sun
这意味着它的一个极点直接指向太阳，
and gradually reverses over the course of a Uranian year.
并在一个天王星年中逐渐发生了逆转。
So summer in the northern hemisphere lasts 42 Earth years followed by 42 years of winter.
所以北半球的夏季持续了42个地球年后是42年的冬季。
42 years of summer, now that's a vacation, or it would be if weren't, like, the coldest planet in the solar system.
42年的夏季，只是一个假期，如果它没夏季，会是太阳系中最冷的行星。
But now, let's leave our solar system and consider Kepler 413b.
但现在，我们不要考虑太阳系了，想想开普勒413b行星吧。
Its axial tilt actually wobbles, or precesses like a spinning top,
它的轴向倾斜实际上是摇晃的，或是像陀螺一样前倾，
varying by as much as 30 degrees over 11 of its years.
在11年里变化多达30度。
This means seasons there change fast, furiously, and unreliably from year to year.
这意味着一年又一年里，它的季节变化非常快，也很剧烈，而且不可靠。
You'd hardly know whether to reach into your closet for a balaclava or a bikini.
你几乎不知道该到衣橱里找件巴拉克拉法帽还是比基尼。
Our planet also undergoes this kind of precession but much more gradually.
我们的行星也经历了这种岁差，但是渐变进行的。
Our tilt changes 23.5 degrees over 26,000 years that's 1 degree every 72 years.
我们的倾斜度在2万6000多年中改变了23.5度，也就是72年改变1度。
There are probably lots of other planets like 413b out there with their own weird axial tilt oddities
或许还有很多类似413b那样轴倾角非常怪异的行星，
just waiting to be discovered.
等待着被发现。
But so far, astronomers haven't found many other examples with such extreme variations of seasons.
但目前为止，天文学家们还没有找到许多有如此极端季节变化的例子。
Just goes to show, anything we can imagine in fiction may be out there in the universe.
我们在科幻小说中想象的任何东西都可能存在于宇宙中，只要去展示。
For now, if you want to experience Game of Thrones-like seasons,
现在，如果你想体验一场类似《权力的游戏》的季节变化
you'll have to wait until we can travel 2,300 light years to Kepler 413b.
你必须等着，直到我们能穿越2300光年到达开普勒413行星。
Thanks for watching this episode of SciShow Space
感谢您收看本期的太空科学秀，
and thanks to all of our Subbable subscribers who make this channel possible.
同时感谢能让本节目存在的Subbable订阅者，
If you'd like to support us and score some cool gear, go to subbable.com to learn more.
如果你想支持我们，获得一些很酷的装置，就登陆subbable.com了解更多信息吧。
And if you have questions or ideas for an episode you'd like to see,
如果你对想看的某期有什么想法或疑问，
you can find us on Facebook and Twitter and in the comments below.
可以在脸书和推特上找到我们，并在下面留言。
And if you want to keep getting smarter with us,
如果你想变得更聪明的话，
just go to youtube.com/scishowspace and subscribe.
就登陆youtube.com/scishowspace点击订阅吧。
