The
definition of planet, since the word was coined by the
ancient Greeks, has included within its scope a wide range of celestial bodies.
Greek astronomers employed the term
asteres planetai (ἀστέρες πλανῆται), "wandering stars", for star-like objects which apparently moved over the sky. Over the millennia, the term has included a variety of different objects, from the
Sun and the
Moon to
satellites and
asteroids.