When the second satellite passes over that high gravity spot, it also speeds up and closes the distance.

当第二个卫星经过时，它也移动更快，拉回本来的距离。

As the first satellite passes over a spot with higher gravity, its orbit speeds up and the two satellites pull apart.

当第一个卫星经过一个重力比较大的地方，它的轨道会被加速然后两个卫星距离被拉开。

As a satellite passes overhead it sends out a radio signal that can be detected by a receiver in a car's computer.

卫星从高空经过时发出能被汽车上计算机里的接收器辨认的无线电信号。

There are many websites that offer information on satellite passes and astronomical phenomena.

有许多网站提供有关卫星通行证和天文现象的信息。

But if the leading satellite passes over a spot with low gravity, it slows down and the second satellite catches up a bit before passing over the slow spot itself.

但是当第一个卫星经过一个重力比较小的地方，它会被减速而缩短距离，当第二个卫星经过，又回复原样。