[felipeerias]

It was actually extremely complex and sophisticated. Getting accurate measurements was seriously tricky and making sense of them involved doing complex calculations (particularly spherical trigonometry) by hand. Some phenomena, like the precession of the equinoxes, required aggregating observations which had been taken over several centuries.

A good book to get a sense of this complexity is “The Light Ages” by Seb Falk.

[WalterBright]

Unfortunately, a calculation that matches a pattern does not confer any understanding of the nature of the solar system.