Ancient astronomy refers to the study of celestial bodies by early civilizations, who observed the night sky to understand time, seasons, and navigation. Cultures such as the Babylonians, Egyptians, and Greeks developed calendars based on lunar and solar cycles, using their observations to predict events like eclipses and solstices. Many ancient societies built structures, like the Stonehenge in England and the Pyramids of Giza, aligned with celestial events. The Maya civilization also created complex astronomical systems, tracking planets and stars, which played a crucial role in their agricultural and religious practices.