Astronomy and Space

Counter-Earth

The Counter-Earth is a hypothetical body of the Solar System that orbits on the other side of the Solar System from Earth, e.g. at the L3 Lagrange point of the Sun–Earth system. A Counter-Earth, or Antichthon (Greek: Ἀντίχθων), was hypothesized by the pre-Socratic Greek philosopher Philolaus (c. 470 – c. 385 BC) to support his non-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", and has been a recurring theme in UFO claims, as well as in fiction (particularly science fiction).

Also on this shelf

See also

• ▸Ion thruster
• ▸Buddha contemplation
• ▸5 Leonis Minoris

Uncatalogued shelf

Text from Wikipedia; plate via Wikimedia Commons. Text CC BY-SA 4.0; plate freely licensed (see Commons). Source record. Images and catalogue data are reproduced from open-access collections.