Complex sentence: Archeologists and anthropologists have determined the Pawnee had a sophisticated understanding of the movement of stars, so that they noted the nonconforming movements of both Venus (Evening Star) and Mars (Morning Star).
Split into simpler sentences: Archeologists and anthropologists have determined the Pawnee had a sophisticated understanding of the movement of stars. They noted the nonconforming movements of both Venus (Evening Star) and Mars (Morning Star).