[RoN_Rancor]

(It is interesting to note that Earth's moon, which is the one generally referred as "the Moon", is not technically a Moon, as it has too much gravitational effect on the Earth to be classified as such, and therefore technically forms a two-planet system with Earth...)

I don't think that the earth and moon are considered a two planet system (of couse I could be completely wrong) because wouldn't the earth and the moon have to revolve around each other for that to be the case? (like in binary star systems). Of couse, I don't think pluto's moon does that, and I know that it is considered a binary planet with pluto. But, yeah the moon is incredibly large proportionally to the earth when compared to other natural satilites around the other planets. It is only second to pluto's moon in that regard. If I remember correctly, our moon was created when something huge collided with the earth while it was forming forcing massive amounts of matter to accumulate in orbit around the earth.