Page 100: Gaia has to be Solaria.
Page 150: Okay, Gaia must be Aurora.
Page 220: Alright, may be it is the Earth.
Pahe 270: Nope, I think it is Aurora.
Page 300: Yeah, definitely Aurora!
Page 350: Oh my God! It is actually Solaria!

Page 400: Okay, Gaia is a whole new and different world!

Still don't know what happened to Solaria! It has been 8 books now, but I guess I will have to read one more book to find out. Fine.