WARNING: SPOILERS ON THIS PAGE.
Earth is the home planet of the human race and the birthplace of all Top o Nerae! Gunbuster characters. In Top o Nerae! Gunbuster, Noriko Takaya and Kazumi Amano's main goal was to protect the future of the inhabitants of Earth from the Space Monsters. In Top o Nerae! 2: Diebuster, Earth was weaponized in an attempt to defeat the Space Monsters, but Buster Machine 7 prevented this.
Earth is a 12,742km in diameter. Its surface is composed mostly of water and is illuminated by the lights of human civilization. Upon Noriko Takaya and Kazumi Amano's return in 14048, these lights were shut off and then used to spell out 「オカエリナサイ」, or "Welcome Home" in English. However, since so much time had passed, there was a language barrier, and the inhabitants of earth accidentally wrote the 「イ」backwards.