Historical astronomy is the study of how ancient cultures understood and observed celestial bodies, such as the Sun, Moon, and stars. This field examines the development of astronomical knowledge and practices over time, including the creation of calendars and navigation techniques. Ancient civilizations, like the Babylonians and Greeks, made significant contributions to astronomy, laying the groundwork for modern science. They used tools like the astrolabe and observatories to track celestial movements, leading to early theories about the structure of the universe and the nature of planets.