这次碰撞已将大量的物质散发到了太空，从而形成了环绕地球的光环，类似于那些现在装饰土星的光环，但是要厚得多。
This impact would have sprayed huge quantities of material into space , forming a ring around Earth similar to , but much thicker than , those that now adorn Saturn .
10亿个地球才能将这个光环填满。
It would take about a billion earth to fill the ring .
地球光环