# Astronomy in Babylon

The Assyrians, Sumerians, Akkadians, Babylonians and, in general, all civilizations that occupied the Middle East in ancient times, studied the movements of the Sun and the Moon to perfect their calendar. They used to designate as the beginning of each month the day after the new moon, when the first lunar room appears. At first this day was determined by observation, but later the Babylonians tried to calculate it in advance.

The first known astronomical activities of the towns that occupied Mesopotamia date from the 8th century B.C. It is known that they accurately measured the month and the revolution of the planets.

The oldest observation of a solar eclipse also comes from the Babylonians and dates back to June 15, 763 BC. The Babylonians calculated the periodicity of the eclipses, describing the Saros cycle, which is still used today. They built a lunar calendar and divided the day into 24 hours. Finally we were bequeathed many of the descriptions and names of the constellations.

Around 400 B.C. they verified that the apparent movements of the Sun and the Moon from West to East around the zodiac do not have a constant speed. It seems that these bodies move with increasing speed during the first half of each revolution to an absolute maximum and then their speed decreases to the original minimum. The Babylonians tried to represent this cycle arithmetically by giving the Moon, for example, a fixed speed for its movement during half of its cycle and a different fixed speed for the other half.

They further perfected the mathematical method by representing the speed of the Moon as a factor that increases linearly from minimum to maximum during the middle of their revolution and then drops to the minimum at the end of the cycle. With these calculations the Babylonian astronomers could predict the new moon and the day on which the new month would begin. As a result, they knew the positions of the Moon and the Sun every day of the month.

Similarly, they calculated the planetary positions, both in their movement to the East and in their retrograde movement. Archaeologists have unearthed cuneiform tablets showing these calculations. Some of these tablets, which have their origins in the cities of Babylon and Uruk, on the banks of the Euphrates River, are named after Naburiannu (about 491 BC) or Kidinnu (about 379 BC), astrologers who must have been the inventors of the calculation systems

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