【英语时差8,16】陨星（上）（在线收听）

You’re out on a clear, starry night with your best friend, looking for shooting stars. Look, there’s one! your friend shouts. But by the time you look, it’s gone. There’s another! she cries. Too late; you missed it. Then one comes along that seems to just amble across the sky, nice and slow. Why is it that some shooting stars are so fast and others are much slower? Well, there are a few reasons. Shooting stars are actually small meteors. Meteors are essentially icy rocks that come from space and burn up from the friction of entering our atmosphere. A very small rock will burn up quickly and be gone almost before you can see it. A larger rock will take a while, and leave a long, bright streak in the sky.