It gave Earth a magnetic shield against the dangerous solar wind.
它给地球一个磁场来抵抗危险的太阳风
And it left us the Moon that provides climatic stability.
还留下了一个月球来确保气候的稳定
If the collision had never happened,Earth may never have been a home to complex life.
如果没有这次撞击 地球永远不会成为复杂生命的家
We've seen the extraordinary consequences of just one chance event on the Earth's destiny.
我们看到地球命运一次意外 就带给我们多么不寻常的结果
But there's another chance factor that was just as vital,its location.
但是还有一个因素也很重要 它的位置
It's only when you consider our planet's position in the solar system
只有思考一下我们的星球在太阳系中的位置
that you really begin to understand how fortunate it's been.
你才真的意识到我们多么幸运
Too far from the Sun, like Mars, and it's simply too cold for life.
如果离太阳太远,像火星那就会太冷,不适宜生命生长
A little closer and things improve.This is where you find the Earth.
离太阳稍微近一点就好了 你会发现地球在这里
We are lucky enough to be in the only place
我们很幸运占据这个太阳系唯一的位置
in the solar system, to our knowledge, that's the right temperature for water,
这里的温度适合水存在
the most essential ingredient for life to exist on the surface.
水是生命存在的最关键因素