Summerians The interpretation of ancient Sumerian texts and artifacts has led some people to believe they provide evidence of extraterrestrial contact or influence on human civilization. Supporters of this theory argue that the Sumerians, who lived in Mesopotamia over 4,000 years ago, possessed advanced knowledge and technology that could not have been achieved without outside help. They point to Sumerian depictions of “gods” who were depicted with unusual physical features, as evidence of extraterrestrial visitation.