An illuminating fact of history is that the wise ones of ancient (i.e., black) civilizations had this all figured out long before Alexander "the Great" bullied his way into the Holies of Holies. The sages of that time had enough sense not to include Pluto as a planet -- there are too many other big rocks floating around in the Kuiper Belt that fit that same description to be calling them all planets, which is why modern day astronomers had to back off calling Pluto a planet.
Kemet formally recognized eight celestial objects in our solar system:
Earth
Moon
Mercury
Venus
Sun
Mars
Jupiter
Saturn
Note that Uranus and Neptune are also not in the list, including the Moon and the Sun instead as they are, inarguably, infinitely more influential on dharma, the mental virtue, of our age.
There were only eight for a good, divine, reason -- what Gurdjieff called the Law of Octaves, which is intimately related to the Law of Seven, which is why the number seven appears all up in the book of Revelations, and is why, when I play a major scale, I play eight notes -- Do-Re-Mi-Fa-So-La-Ti-Do -- really seven, as the Do is both Beginning and End, the Alpha and the Omega, world without end.
When the uninitiated attempt to explain our universe, they only add dissonance, not harmony, to the cosmos.