Phaeton (Faeton, Φαέθων) was a planet that has recently (about ~ 3000 years ago) disappeared from our Solar System….The ancient Greeks were known to diligently observe the planets because they believed that “gods” traversed the sky and navigated between stars in space. Planets are fairly easy to distinguish from stars with the naked eye because they "move" in relation to the "fixed" system of stars and constellations that the ancient Greeks called "the cosmos".