1. Ancient Astronomers

2. The Mayans Who: Native people of Mexico When: As early as 1800 BCE. All 1450 cities were abandoned in 900 CE Where:Yucatan peninsula stretching down to central America. What: One of the most sophisticated tribes in the Americas. They had a written language, a number system, permanent houses, calendars and their own sport.

3. Number System Used a base of 20 (as opposed to our 10) Developed the concept of “ zero ” Dot = unit of 1 Dash = unit of 5

4. Astronomy Dresden Codex detailed account of the observations Repetitive cycles of the moon, sun and planets Codex includes: Eclipse table Venus table Mars table

5. Accuracy PhenomenonMayan CountModern Count Lunar Month29.53 Solar Year365.24 Period of Venus583.92583.93 Period of Mars780779.94

6. Mayan Contributions

7. The Egyptians Who: One of 3 dominant races; usually linked with the fertile crescent When: 3100 BCE to 31 BCE Where: Egypt (Northern Africa) along the Nile River

8. The Nile River Source of livelihood for the Egyptians Flooded yearly Provided rich soil for agriculture Occurred on the summer solstice This allowed the priests to: Predict the coming flood Create a calendar

9. Calendar 365 days 12 Months Each one with 30 days 5 day feast period at the end They knew they were missing ¼ of a day This caused calendar to cycle through every 1460 years.

10. Buildings Pyramids The four corners of most pyramids line up with the four cardinal directions North / South East / West Many also lined up with the three stars in Orion ’ s belt

11. Egyptian Contributions