接著就下了好幾千年的暴雨
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,
開始注滿我們年輕地球上比較低的區(qū)域
possibly creating the firstoceans.
倉創(chuàng)造出第一片海洋
But it's reckoned that even this relentless downpour
但是據(jù)分析即使是這次無窮無盡的傾盆大雨
only delivered around half the water that makes up our oceans today.
也只不過造成了我們今天海洋的一半水
The rest came from outer space.
其它的水都是從外太空來的
This is a comet filmed in 2005.
這是2005年拍攝的一顆彗星
It's about four miles across and, like all comets,
直徑大概有6公里和其它彗星一樣
it's made of rock and water in the form of ice.
它是由巖石和以冰的形式存在的水組成的
To discover just how much water comets contain,
為了了解彗星包含了多少水
scientists deliberately crashed a space probe straight into it.
科學(xué)家們故意指揮一個衛(wèi)星與之相撞
After it ploughed into the surface,
它撞進彗星表面的時候
more than 250,000 tons of water burst into space.
超過2億5千萬升水 沖進了太空