The Luminoth race lives on Aether in Metroid Prime 2: Echoes. Samus arrives there while investigating a missing Galactic Federation patrol and discovers that the planet has been devastated by a war with the hostile Ing.
Aether is not an ordinary world in the game’s story. A Phazon meteor struck it decades earlier, splitting reality and creating a parallel dimension called Dark Aether. The two worlds share a general layout, but Dark Aether is barren, poisonous, and hostile to life. The Ing seize the planet’s energy, known as the Light of Aether, and use it against the Luminoth.
The Luminoth built temples and energy controllers to protect their world. Samus helps reclaim the stolen energy from Dark Aether and return it to Aether, restoring the planet’s stability. The last surviving Luminoth, U-Mos, guides her through much of this mission, while most of his people remain in hibernation.
SR388 is associated with the Metroids, Zebes with the Chozo and Space Pirates, and Tallon IV is the main setting of the first Metroid Prime.