Celestial bodies fascinated the peoples of ancient Mesopotamia. Both the Sumerians (ca. 3400-2335 BCE) and the Akkadians (ca. 2360–2180 BCE) named the more striking groupings of stars including all the zodiacal constellations after animals and occupations. While they saw the sun, moon, planets, and stars as signs signalizing the seasons and for marking time by days, months, and years.

Their preoccupation with the stars, which in their thinking were either gods or symbols of the gods, gave rise to astral religious cults immersed in polytheism. These deities, which exhibited the appetites and characteristics of mortals, lived with sin and involved themselves in the powers of darkness. In Mesopotamian thought human culture and society reflected that of the community of the gods.

Principal among Mesopotamian celestial divinities were Inanna, Nanna, and Utu, linked with the planet Venus, the moon, and the sun, respectively. (Finegan 1989:26).

Inanna (Sumerian, Inanna; Akkadian, Istar), the “queen of heaven” and the goddess of fertility and war, was the chief god of the Sumerian pantheon. She was the morning and evening star (the planet Venus), the daughter of Nanna (the moon-god), and the sister of the Utu (the sun-god) and Iškur (the storm-god). Nanna (Sumerian, Nanna; Akkadian, Suen, later Sin) was the moon-god, the measurer of time, and the regulator of the tides. Cult centers in the worship of Nanna, the moon-god, included Ur and Haran. Utu, the Sumerian god of the sun and order and justice, was the son of Nanna and the brother of Inanna.