Terra Versions
Final Fantasy IX
Terra (テラ [terra] in Japanese) is the secondary world from Final Fantasy IX. It is an ancient planet, so ancient that its life has almost run out thousands of years ago already. The last of its civilizations, a highly advanced technological race, decided to fuse their worlds with another, younger one, which would then give all its life for the benefit of Terra. All the people of the world preserved their souls through some technology, and a genome was set in charge of the planet. The plan was then put in motion, and Terra went to sleep within the planet of Gaia, a young and vital planet. A soul conductor, the Iifa Tree was put in place to recycle the energy of Gaia's planetary crystal into the Terra crystal's use, and eventually complete the fusion of the two worlds.
It is unknown how exactly the fusion worked, but during the adjustment phase Terra existed within Gaia (possibly slightly out of phase into another dimension), but its moon (red) was visible in Gaian skies along with Gaia's own (blue) moon. The red color of the Terran moon reflected the red spectrum of the essence of Terra's planetary crystal. Refer to the page on Gaia for details on the combined moon cycles.
In the end, the plan to fuse the two worlds failed due to the actions of the genomes Kuja and Zidane Tribal. The red moon disappeared from Gaian skies. It is unknown what happened to the slumbering Terran souls.