Ancient Foundations Astronomy is one of the oldest natural sciences, originally developed by indigenous cultures for timekeeping, navigation, and spiritual purposes. The Babylonians (c. 1000 BCE) were among the first to distinguish the "wandering" planets from fixed stars and developed complex mathematical systems to predict celestial events. They established the zodiac and the sexagesimal (base 60) system, which is still used to measure time and angles today.

The Greek Era Ancient Greek astronomers shifted focus toward geometric models of the cosmos. While Aristarchus of Samos proposed an early sun-centered (heliocentric) model, the Earth-centered (geocentric) view championed by Aristotle and Ptolemy became the standard for over a millennium. Hipparchus contributed significantly by compiling the first Western star catalogue, discovering th ...