TL;DR: Moon has marias and craters - how did that fit into the idea of the celestial spheres being perfect bodies?

Full question:

In the geocentric model of cosmos, the earth was at the center with the celestial spheres - the moon, the sun and the planets - rotating in perfect circular orbits around the earth. Moreover, these celestial spheres were considered to be perfect bodies.

It's well known how people like Copernicus, Kepler, Galileo and Newton contributed to the heliocentric model. One of Galileo's contributions was that he used the new telescope technology to observe how the sun had spots, which didn't make sense according to the idea that the celestial spheres were perfect bodies.

But what about the moon? If the moon was considered a perfect body in the age of the geocentric model, how did natural philosophers and scientists at the time explain its plains and craters which are clearly seen even without a telescope? I mean, even if you don't know they are plains and craters, you can see that the so-called perfect sphere isn't perfect. In other words, the moon appears to have spots.

Edit: added information about moon's marias (plains).