There are still lots of things about space that we may never be able to answer, like is time travel possible?
太空上依然有很多我们可能永远无法解释的事物，比如时光旅行是否可行？
Or are aliens living somewhere else in the Milky Way?
或者，银河系中是否有外星人？
But there is one thing I believe about space: Space is trying to kill me.
但我坚信一件事：太空正试着杀死我。
Space isn't out to get me personally. It's also trying to kill you and everybody else. Think about it.
太空不仅仅会杀死我，也会将你和其他人杀死。认真想一想。
Space doesn't naturally have what we need to survive when we travel there:
太空不会自然供应生存必需品，让我们进行太空旅行，
no air, it's too hot or too cold, no ozone to protect us from those nasty UV rays, either.
没有空气、有时太热、有时太冷、没有臭氧层可阻挡恼人的紫外线。
This all sounds bad, but what can space really do to me if I stay on Earth?
这些听上去糟透了，但是如果我就呆在地球上，太空又会对我有什么实际影响呢？
What we need to understand is that objects in space can cause people to think their days are numbered,
要知道，太空上的事物让人们了解到他们的生命有限，
even when there are events on Earth that can hurt or kill us before something from space does.
即使在地球上，就有很多的事可以将我们置之死地。
So, what are the odds that one of these objects will really affect Earth and you and me in our lifetime?
在太空将我们杀死之前，那么究竟来自太空的某个东西有多大几率，真的会影响地球、你、我、还有我们的一生？
Well, we can take what we know about the universe to try and figure that out.
好，我们可以凭借着我们对宇宙的了解试着弄明白。
You might have heard stories about asteroids hitting the Earth. That would be pretty bad.
你也许听说过关于小行星撞击地球的故事。这听上去很糟糕。
Scientists think asteroids might have killed off most of the dinosaurs.
科学家们认为小行星消灭了大多数的恐龙。
Sounds like something we should worry about, right?
这听上去像我们需要担心的，是吧？

Well, astronomers can now watch asteroids in space and see them coming using complex computer models to predict the deadly rock's path.
那么，天文学家现在有能力观察在太空中的小行星，通过复杂的计算机模型来预测这些致命的岩石路径。
For a while, the reported odds that asteroid Apophis would strike Earth in 2036 were once 1 in 625.
曾有一段时间，有报告称，阿波菲斯小行星在2036年袭击地球的概率是六百二十五分之一。
But, after updating their data, astronomers now say the chances are extremely low. Okay, what about the sun?
但是，在他们最新的报告中，天文学家们称行星撞击地球的机率极低。好吧，那太阳呢？
Hollywood movies like to pick on our sun by showing Earth destroyed by solar flares or the sun dying out, which would cause Earth to freeze.
好莱坞电影往往喜欢以太阳作为题材，来暗示太阳耀斑将会摧毁地球，又或者太阳正在消亡，从而导致地球冻结。
Astronomers predict our sun contains enough gas to make energy for another 3 to 5 billion years.
天文学家推测我们的太阳包含足够的大气资源，足够供我们使用额外的3到5亿年。
So, in 3 to 5 billion years, if people still exist on Earth, they'll have to deal with that. But today, well, we're safe.
所以，3至5亿年之后，如果地球上仍然有人，他们将不得不面对这个难题。但至少现在，我们很安全。
Sometimes the sun does shoot flares at Earth,
尽管有时太阳会爆发太阳耀斑，
but the magnetic fields surrounding our planet blocks most of that radiation.
但是环绕在我们地球周围的磁场将会阻挡大多数的辐射。
The radiation that does get through creates things like the Aurora Borealis.
剩余的小部分辐射变成极光之类的东西。
Gigantic solar flares can mess with our satellites and electrical equipment, but the chances of it killing you are pretty slim.
巨大的太阳耀斑可以摧毁我们的卫星和电气设备，但事实上你死于太阳耀斑的几率十分小。
Okay, what about that supermassive black hole in the middle of our galaxy?
好吧，那么在我们银河系内的超大质量黑洞呢？
What happens to Earth, and us, when it pulls us in? After all, it is supermassive.
当它试图吞噬我们的时候，又会对地球、对我们产生什么影响呢？毕竟，它是超大的。
Nope, not going to happen. That's one big object that can't bother us. How can we be so sure?
庆幸的是，这不会发生。它就是一个不会对我们有任何影响的大物体。我们怎么能这么肯定？
Our solar system is on the edge of the Milky Way while the nearest supermassive black hole is about 26,000 light years from Earth.
因为我们的太阳系在银河系的边缘上，即使是最近的超大质量黑洞，距离地球也约有26000光年。
That means we aren't on that black hole's menu.
这意味着我们不会在黑洞的吞食名单上。
So, you still think space objects are trying to kill you even after what I've told you so far?
所以，即使在我解释之后，你是否依然认为不明太空物会消灭你？
I think I've even convinced myself that odds are really good that space and the objects up there won't kill me after all.
我觉得我甚至已经说服我自己，那些太空危机发生的几率非常之小，完全不足以杀死我们。
But I'll probably keep looking up just to make sure nothing is headed my way.
但我依旧观察着，只是想确定没有什么意外发生。