>>54566715pokemon has a lot of parallels to the real world. regions are based on real life countries. there's a single sun and moon in the sky so it's clear that poke earth resembles a lot like real earth. so that means poke earth is part of a solar system a lot like ours.
you're claiming the poke solar system only has the earth, sun, and moon. and you claim other solar system planets don't exist. do you have any proof?