接着就下了好几千年的暴雨
As the first rivers formed,
第一片河流形成后
they began to fill up the lower lying areas on ouryoung planet,
开始注满我们年轻地球上比较低的区域
possibly creating the firstoceans.
仓创造出第一片海洋
But it's reckoned that even this relentless downpour
但是据分析即使是这次无穷无尽的倾盆大雨
only delivered around half the water that makes up our oceans today.
也只不过造成了我们今天海洋的一半水
The rest came from outer space.
其它的水都是从外太空来的
This is a comet filmed in 2005.
这是2005年拍摄的一颗彗星
It's about four miles across and, like all comets,
直径大概有6公里和其它彗星一样
it's made of rock and water in the form of ice.
它是由岩石和以冰的形式存在的水组成的
To discover just how much water comets contain,
为了了解彗星包含了多少水
scientists deliberately crashed a space probe straight into it.
科学家们故意指挥一个卫星与之相撞
After it ploughed into the surface,
它撞进彗星表面的时候
more than 250,000 tons of water burst into space.
超过2亿5千万升水 冲进了太空
