Pluto and the others are planets even without including them all in the mnemonic. The mnemonic is for the first 9 planets, just like you only remember the first few digits of pi.
The moons of Jupiter and Saturn were called satellite planets from their discovery until sometime in the 20th century.
The first several asteroids were called planets, until enough were discovered that the term ‘asteroid’ was invented and they were renamed.
The first Kuiper belt objects were called planets, until enough were discovered that it turns out Pluto is mostly just a particularly reflective example.
Pluto and the others are planets even without including them all in the mnemonic. The mnemonic is for the first 9 planets, just like you only remember the first few digits of pi.
Pluto was not the first 9th planet. Then again we were up to 13(?) at one point.
Because Pluto is the 9th planet?
How are you counting?
They actually know their history, which you clearly don’t
The moons of Jupiter and Saturn were called satellite planets from their discovery until sometime in the 20th century.
The first several asteroids were called planets, until enough were discovered that the term ‘asteroid’ was invented and they were renamed.
The first Kuiper belt objects were called planets, until enough were discovered that it turns out Pluto is mostly just a particularly reflective example.
Ceres is between Mars and Jupiter.