In Classical antiquity, the classical planets or naked eye planets were the seven non-fixed objects visible in the sky: the Sun, the Moon, and the  planets Mercury, Venus, Mars, Jupiter, and Saturn. The word planet comes from the Greek word πλανήτης, planētēs, meaning "wanderer", because ancient astronomers observed how certain lights moved across the sky relative to the fixed stars. They called these objects asteres planetai, which means wandering stars.