Editing Counter-Earth (section)

{{short description|Hypothetical planet on the other side of the Sun from Earth}}
[[File:Antichthon.svg|thumb|250px|right|Philolaus believed there was a "Counter-Earth" (''Antichthon'') orbiting the "Central Fire" (not labeled) that was not visible from Earth. The upper illustration depicts Earth at night while the lower one depicts Earth in the day.<ref name="DatEA">Source: ''Dante and the Early Astronomers'' by M. A. Orr, 1913.</ref>]]
The '''Counter-Earth''' is a [[:Category: Hypothetical bodies of the Solar System|hypothetical body of the Solar System]] that orbits on the other side of the [[Solar System]] from [[Earth]]. A Counter-Earth or '''''Antichthon''''' ({{langx|el|Ἀντίχθων}}) was hypothesized by the [[pre-Socratic philosophy|pre-Socratic]] [[Ancient Greece|Greek]] [[philosopher]] [[Philolaus]] ({{Circa|470|385 BC}}) to support his non-[[geocentric model|geocentric]] [[cosmology]], in which all objects in the universe revolve around a "Central Fire" (unseen from Earth and distinct from the [[Sun]] which also revolves around it).

In modern times a hypothetical planet always on the other side of the Sun from [[Earth]] has been called a "Counter-Earth",<ref name=Comins>{{cite book|last= Comins|first=Neil F.|title=What If the Earth Had Two Moons?: And Nine Other Thought-Provoking ...|year= 2010|publisher= macmillan|pages=171–172|url= https://books.google.com/books?id=TNqBI4QKZSAC&q=counter-earth&pg=PA171|isbn=9781429957939}}</ref> and has been a recurring theme in [[Unidentified flying object|UFO]] claims,<ref name=UFO/> as well as in fiction (particularly [[Fictional planets of the Solar System#Counter-Earth|science fiction]]).