There were junior priests, counselors, musicians, potters, etc. Later, it became necessary to have military leaders and some of these became kings. In order to be able to communicate with the gods, mounds were built which represented shrines. The Sumerian baru-priests were under quite a bit of pressure to predict correctly. Predictions became more an art than science, since the priests had to be a bit crafty in their work.
Astronomy is the scientific study of the stars and planets and their movements.
Astrology as we, or even the ancient Greeks, would consider it did not exist at this time. The beginnings of actual astrology can be seen during the Old Babylonian period, during the second millennium. The focus of the Babylonians was on the well-being of the kingdom and the king, not of the individual. For this reason, predictions revolved around things that would affect this well-being. Venus became associated with love and war.