what were their major religious deities?
Enil, Enki, etc.
Sumerian religion
Enki was god of freshwater, male fertility, and knowledge. 
how is venus depicted in culture? In Sumerian religion, Inanna was associated with the planet Venus. in which areas was this religion practiced? Sumer, first literate civilization of ancient Mesopotamia. what are the origins of this religion's name? UNANSWERABLE
wiki:24636036
Sumerian religion [SEP] Major deities
Ninurta was the son of Enlil and Ninlil. He was worshipped as the god of war, agriculture, and one of the Sumerian wind gods. He was the patron deity of Girsu and one of the patron deities of Lagash. Enki was god of freshwater, male fertility, and knowledge. His most important cult center was the E-abzu temple in the city of Eridu. He was the patron and creator of humanity and the sponsor of human culture. His primary consort was Ninhursag, the Sumerian goddess of the earth. Ninhursag was worshipped in the cities of Kesh and Adab.