This is our planet the Earth.

这是我们的星球，地球

It's unique in the solar system, perhaps even in theuniverse.

在太阳系这是独一无二的，也许甚至在宇宙中也是

My name is Iain Stewart

我叫伊恩.斯图尔特

and I want to show you how our planet works.

我想告诉大家我们的星球是怎样运作的

I'm exploring the atmosphere.

这星期我们讲述的是大气层

The atmosphere creates our climate

大气创造了我们的气候

and protects us against the cold hostility of space.

保护我们不受宇宙寒冷的袭击

And it provides oxygen to fuel our bodies.

并且为我们的身体提供氧气

Our atmosphere is full of contradictions.

我们的大气层充满了矛盾

It's immensely powerful and yet it's incredibly sensitive.

它非常强大 但也很容易遭到破坏

It's destructive and at the same time it protects us.

它具有破坏性，但同时也保护着我们

It's essential for all life and yet it was created by life.

它对所有的生命来说很重要，但它也是由生命所创造的

Without it, the planet would be utterly uninhabitable.

没有大气层，我们的星球可能会完全不适于居住