Planet X



Planet X is a theoretical trans-Neptunian planet in the Terran Solar System whose existence would explain irregularities in the orbit of Neptune. In Ultima II, the mysterious planet is shown to exist in the twenty-second century of  Earth's history as impacted by the enchantress Minax. It is possible and necessary to visit Planet X (located at coordinates 9, 9, 9) using a rocket ship, which can be acquired at the post-apocalyptic Soviet settlement of Pirates Harbour.

Description
Planet X was first named by astronomer Percival Lowell, a personage whom the Avatar eventually had the privilege of meeting in Martian Dreams. Certain that a ninth planet existed, Lowell built an observatory in Flagstaff, Arizona and began to look extensively for the theoretical. While he failed in this endeavor, Lowell's observations eventually led to the discovery of Pluto, a large dwarf-planet with an orbit beyond Neptune.



Eventually, in the 1990s of standard Earth history, other orbiting objects in this range were discovered, including the plutoid dwarf-planets Haumea,  Makemake and  Eris. None of these, however, contained mass which would be necessary to account for Lowell's theory, and in contemporary astronomy, the theory of Planet X has been largely discarded, given new observations which would account for the variations in the outer planets' orbits.

However, within the history forged by Minax's interventions on Earth, Planet X was a reality. The planet, while still unknown to the majority of terrestrial civilization, had been located by a number of astronauts and theorists dwelling in the ninetieth millennium B.C. and the Stranger, requiring the blessing of the fabled Father Antos, found it necessary to explore this strange new world. The hero found it to be a planet much like Earth, home to continents and oceans, and inhabited by beings who dwelt in the settlements of Towne Basko and Castle Barataria, under the rule of the enigmatic King Ozymandias.

It is not known if a Planet X exists in the reality of the universe unaffected by Minax's machinations, but Father Antos later would appear on the world of Britannia, indicating that he, if nothing else, survived the return to temporal normalcy.