Final answer:
Ancient astronomers divided the sky into regions containing distinct groups of stars called constellations, with some stars, known as planets, moving differently along the ecliptic.
Step-by-step explanation:
Ancient astronomers divided the sky into regions containing distinct groups of stars called constellations. These constellations were patterns identified by various civilizations to navigate among the stars and pass down astronomical knowledge. While most stars maintain fixed positions relative to each other, forming the backdrop for these constellations, the ancients noticed that five stars, which they named planets (Greek for wanderers), moved differently. These planets followed a path close to the ecliptic, similar to the Sun and Moon, and include Mercury, Venus, Mars, Jupiter, and Saturn. Observing these celestial movements, and especially the regular motion of stars, ancient cultures were deeply influenced by the night sky, leading to the development of astronomy as a science.