Ancient civilizations used astronomy to create calendars primarily by observing the movements of celestial bodies—mainly the Sun, Moon, and stars. Here’s how they did it:
🌞 Solar Observations
- Egyptians noticed the annual rising of the star Sirius (just before sunrise) coincided with the Nile River’s flooding, a crucial event for agriculture.
- They developed a solar calendar with 365 days, dividing the year into 12 months of 30 days, plus 5 extra days.
- The Sun’s position at different times of the year (solstices and equinoxes) helped them track seasons.
🌙 Lunar Calendars
- Many civilizations, like the Babylonians, used the phases of the Moon to measure time.
- A lunar month (from new moon to new moon) is about 29.5 days, so they built calendars around 12 lunar months (~354 days).
- Because lunar calendars fell short of the solar year, some cultures added intercalary months to realign with the seasons.
🌟 Star and Constellation Tracking
- The Maya were incredibly advanced, using the position of Venus, eclipses, and constellations to guide their ritual calendar (Tzolk’in) and civil calendar (Haab’).
- The Chinese tracked stars and planetary motion to define their lunisolar calendar, which still influences Chinese New Year today.
🛕 Calendar Stones and Architecture
- Structures like Stonehenge and the Mayan pyramids were aligned with astronomical events (like solstices), acting as massive calendars.
- The Aztec Sun Stone combined solar tracking with mythological cycles.