Why doesn't Earth's Moon have a Moon of itself?

Ah! This is a nice question. And you shouldn't be anonymous to ask this. No shame, since majority of the people don't even ask this question, assuming that they already know the answer. read more

Radius of the moon is 1,737 km. So assuming a large body of similar rocky composition as moon, the body must be at least 4342.5 km far from the moon, so as to not get sheared. read more

Because of the mass of the earth is so close, the Earth-moon system has reached an equilibrium called a tidal lock, which mean that the time the moon takes to rotate around its own axis is the same time it takes to orbit around earth. read more

This has to do with the nature of force and motion. read more