外惑星帝国Timeline: Scenario: Desire Drive
The Empire of the Outer Planets was a nation in the Solar System that was established in Year 13,000 after the merging of the nations and colonies on Jupiter, Saturn, Uranus, Neptune, and their Natural Satellites.
The nation slowly became the only one that remained in the Solar System, as starting in Year One Billion, many people from Earth, would start to leave and relocate to other places in the Universe, with some arriving to the Outer Planets itself. The Lunarian Federation followed soon after, teleporting itself to Neo Gensokyo. Finally, in Year Seven Billion, New Chireiden was among the last nation to leave the Solar System. After Mars' survival, in Year Eight Billion, the Outer Planets had decided to annex it.
The Outer Planets continued to exist until Year Fifteen Billion, when a referendum was passed to join the Universal Federation.