1. The Ancient Catalogs
Astronomy was born in the five cradles of civilization, along the Nile Valley in Egypt, the Indus Valley along the western region of the Indian subcontinent, the Chinese city states on the banks of the Yellow River, the ancient regions of Me-soamerica from central Mexico down to the Andean South America and the an-cient city states of Mesopotamia in the fertile crescent. Each of these ancient cul-tures incorporated astronomy into calendar making, religion, mythology, and astrology. Many of these civilizations kept various forms of stars charts, but some of the most complete came Mesopotamia.
Many ancient empires lived in the fertile crescent of Mesopotamia (“the land be-tween the rivers”). The Tigris and the Euphrates rivers provided water and rich fertile soil. It was the origin for the ancient societies of Sumer, Ubaid, Assyria, Akkaid and Babylonia. The oldest known astronomical observations appear in Babylonian Enuma Anu Enlil (translation “In the days of Anu and Enlil”) dating from 1200 BC. Tablet 63 of the Enuma Anu Enlil described the rising and setting of Venus over a period of 21 years. Another Babylonian text containing a compi-lation of astronomical data is the Mul-Apin. The Mul-Apin, written between 1200 and 1000 BC, presented a catalog of major stars and constellations along with their locations. The constellations described in the Mul-Apin are recognized today as the Bull (Taurus), the Lion (Leo), the Scorpion (Scorpio), and the Twins (Ge-mini) and the Sea Goat (Capricorn). Other parts of the Mul-Apin describe methods to measure the length of the day with water clocks and the gnomon. There are some historians that believe the astronomical observations of the night sky led the Babylonians to discover the Earth’s precession. Babylonian astronomy would play an important role in the observations of the Ancient Greeks.
There were many well known ancient astronomers. Aristarchus of Samos (310 BC – c 230 BC) was the first to argue for a heliocentric view of the solar system putting the sun at the center of the Universe but his views were rejected by his contemporaries. Eratosthenes of Cyrene (c 276 BC – c 195 BC) created the tech-nique of measuring locations by using latitudes and longitudes and also accurately computed the circumference of the Earth. Thales of Miletus (c 624 BC – c 546 BC) could predict solar eclipses. It was the astronomer Aristyllus (c 280 BC) with the help of Timocharis (c 320 BC – 260 BC) that became the first astronomers to create star catalogs at an astronomical observatory of the Library of Alexandria. The observations of Aristyllus and Timocharis are the earliest Greek observations that can be dated in the year 290 BCE. It would be Hipparchus of Nicaea that would become known as the founder of astronomy.
1.1. Hipparchus (c. 200–126 BC)
Hipparchus was an astronomer and mathematician that lived in Bithynia (now Turkey). What little we know about Hipparchus is found in the writings...