(单词翻译:单击)
Have you ever wondered what it's like on other planets?
你有没有想过其他星球是怎么样的？
What sights would await you on the red dunes of Mars?
在火星的红色沙丘上，什么景象在等着你？
What it would be like to dance on Saturn?
在土星上跳舞会是什么感觉？
What's waiting beneath the swirling clouds of Jupiter?
在木星的漩涡云下等着的是什么？
Yeah, lots of things would kill you before you ever found out:
没错，很多东西在被你发现之前就能杀了你:
the heat, or the cold, or radiation, potentially crushing gravitation,
热、冷、辐射、潜在的压倒性引力，
and either a total lack of atmosphere or a miasma of poison gases.
还有它们要么完全缺乏大气，要么有有毒的瘴气。
But we're learning more and more about the conditions on our celestial neighbors all the time.
但我们正在不断了解周围天体的情况。
So it's not hard to imagine what it would be like to pay them a visit.
所以不难想象去拜访它们是什么样子。
Take Mercury, for example, the sun's closest pal.
以水星为例，它离太阳最近。
Because it's only fifty-eight million kilometers from the sun, compared to Earth's 150 million kilometers,
因为与日地距离的1.5亿公里远相比，水星和太阳之间的距离只有5800万公里。
on Mercury the sun would appear three times larger than it does from Earth, and six times brighter.
在水星上，太阳看起来比地球大三倍，亮度是地球的6倍。
So, you know, wear sunscreen.
所以，你知道的，要涂防晒霜。
And because it's the closest, Mercury has the shortest orbital period in the solar system,
而且由于水星离太阳最近，它的轨道周期在太阳系中最短。
completing one circuit around the sun in just 88 Earth days.
它的一个完整轨道周期是88个地球日。
But as it travels around the sun, Mercury actually rotates relatively slowly.
但由于水星围绕太阳运行，它的速度相对较慢。
One full rotation, which would be one day on Mercury, takes about fifty-eight Earth days,
一个圆满周期中，水星的一天相当于58个地球日，
so the planet ends up experiencing roughly three days for every two of its years.
所以它每两个地球年就会经历大约3天的时间。
It's also a cute little thing, as planets go, about 4,900 kilometers in diameter.
水星也很可爱，与行星一样，它的直径约为4900千米。
That's about 40% larger that our moon, but it's still only as big across as the continental United States.
它比月球大40%，但它仅和美国大陆一样大。
And as you headed towards the planet, you'd see that it looks a lot like our moon: grey, rocky, and uneven.
当你走向水星时，会发现它很像我们的月球：灰暗、多岩、不平整。
Unlike the moon, though, its surface is rippled with towering ridges called lobate scarps,
不过，与月球不同的是，它的表面被叫做“瓣状陡坡”的高耸山脊所覆盖，
which were created when Mercury rapidly cooled after it formed more than four billion years ago.
山脊是水星在40亿年前形成后迅速冷却时产生的。
In the process of cooling, the planet actually shrank by as much as eleven kilometers in diameter,
在冷却的过程中，它的直径实际上缩小了11公里，
giving it an appearance that's been compared to a dry apple.
使它的外观像干苹果。
As you get even closer to Mercury, you pass through its exosphere,
当你接近水星时，会穿过它的外逸层，
a thin layer of oxygen, hydrogen, helium, sodium, potassium, and other materials,
它是一层薄薄的氧、氢、氦、钠、钾和其他物质，
most of which were knocked off the planet's surface by solar wind and meteoroids.
其中大部分被太阳风和流星体撞击到行星表面。
And, because it has no significant atmosphere to burn up any rocks flying at it from space,
而且，因为水星没有明显的大气层可以燃烧从太空飞来的岩石，
Mercury is also heavily cratered.
它布满坑洞。
One impact four billion years ago was so nasty, it created a crater roughly 1,550 kilometers wide.
四十亿年前的一次撞击非常恶劣，它形成了一个大约1550公里宽的陨石坑。
Known as the Caloris Basin, it's basically the size of Texas.
这就是众所周知的的卡洛里斯盆地，大小基本与德克萨斯州相同。
Now you might well think that Mercury is the hottest planet in the solar system
你可能想水星是太阳系最热的行星，
because it's the closest to the sun, but you'd be wrong.
因为它离太阳最近，但你错了。
That distinction actually goes to Venus.
实际上是金星最热。
Since Mercury has such a weaker atmosphere, it's not very good at retaining heat,
因为水星的大气层非常薄，不擅长保存热量，
so it can get a lot colder than you might think.
所以它比你想得冷很多。
Daytime temperatures can reach 430°C, sure, but at night, they drop to -180°.
它的白天温度可以达到430°C，但晚上就会降至-180°。
That's the biggest temperature swing in our solar system.
这是我们太阳系最大的温度波动。
And in fact, if you were to land in the right crater on Mercury, you might even find ice.
事实上，如果你在水星上合适的陨石坑着陆，可能会发现冰。
Astronomers think they've found evidence of water-ice lurking at the north and south poles,
天文学家认为他们发现了北极和南极水冰存在的证据，
where there are craters so deep that they're perpetually shadowed and cold.
它们在陨石坑深处，被盖住，很冷。
This water was probably delivered to Mercury by the same impacts that gave the planet its pockmarked complexion.
这种水很可能是通过撞击向水星传递的，与造成陨石坑的撞击相同。
So, one last weird thing to keep in mind if you're planning a trip to Mercury
所以，如果你计划去水星旅行的话，最后一件很奇怪的事情是
is that you'd feel a lot lighter there, but not as light as you might expect.
你会觉得那里很亮，但实际情况达不到你的期望。
Even though Mercury is only 40% bigger than the moon, it actually has about twice the gravitation.
虽然水星比月球大40%，但实际上它的引力是后者的两倍。
Standing on Mercury, you'd experience 38% the force of gravity that you'd experience on Earth,
站在水星上，你感受到的38%的重力
compared to just 16% on the Moon. What gives?
在月球上仅为16%。为什么这样呢？
Despite its small size, Mercury is actually the second densest planet in our solar system, thanks to its huge metallic core.
水星尽管体积小，但由于巨大的金属核心，它实际上是太阳系中第二大密度的行星。
At roughly 3,700 kilometers wide, its liquid iron core takes up about 75% of the planet's total diameter.
在大约3700公里宽的地方，它的液态铁核占据了行星总直径的75%。
Since it's so packed with mass, Mercury exerts stronger gravitation, resulting in a lighter step than you take on Earth,
因为它的质量很大，引力更强，导致它上面的脚步声比地球上的要轻，
but not quite the bounce that you get on the moon.
不能像在月球上那样随意弹跳。
Thanks for joining me for SciShow Space.
感谢您收看太空科学秀，
If you wanna keep helping us explore the solar system and the rest of the universe together,
如果你想继续帮助我们探索太阳系和宇宙的其他部分，
just go to subbable.com/scishow,
就登陆subbable.com/scishow，
and don't forget to go to youtube.com/scishowspace and subscribe.
也不要忘了登录youtube.com/scishowspace点击订阅哦。
