Ancient Contact Narratives and the Quest for Extraterrestrial Evidence: Sagan, Shklovsky, and the Oannes Legend

To the point

Carl Sagan and Iosif Shklovsky suggested ancient legends could hint at contact with aliens, but there is no solid proof and a credible case would require a clear nonhuman form, knowledge beyond primitive astronomy, and a definite purpose for the encounter.

Did extraterrestrials visit ancient Sumer?
bigthink.com

Did extraterrestrials visit ancient Sumer?

Written legends allow us to speculate that extraterrestrials may have visited the Sumerians of ancient Mesopotamia.