Question

Why can't there be rains on the moon

Answer 1

The moon's gravity is very limited due to its size. In physics, the larger (or denser) something is, the more gravity it has. The more gravity it has, the more atmosphere it can hold. Atmosphere is all that stuff in the sky that produces rain, snow, lightning, tornadoes, wind--all that precipitation that we see all the time on earth. Since the moon has such low gravity, it has no atmosphere, and hence, no rain.