The moon is slowly moving away from Earth.
月亮正一点一点离我们远去。
It gets a little farther every year.
每过一年，它就走远一点点。
How far? About three centimeters.
有多远呢？大概三厘米。
That is about the width of your finger.
差不多就是一根手指那么宽。
This has gone on for billions of years.
这样已经过了几十亿年啦。
Scientists can measure it with laser light.
科学家用激光就能量出来。
One day, it may be too far to see.
很久很久以后，它可能远到看不见。
