As well as certain constellations and the Sun itself , individual stars have their own myths . To the Ancient Greeks , some " stars " , known as planets ( Greek πλανήτης ( planētēs ) , meaning " wanderer " ) , represented various important deities , from which the names of the planets Mercury , Venus , Mars , Jupiter and Saturn was taken . ( Uranus and Neptune was also Greek and Roman gods , but neither planet was known in Antiquity because of their low brightness . Their names was assigned by later astronomers . )