Greetings one and all. I'm sure that a lot of you who frequent my page are familiar with the programs on educational channels about ancient astronauts. The premise of most of these is that the earth has been visited in the antique and prehistoric past by ancient aliens. These guys allegedly founded human civilizations and possibly even created us, according to devotees. So goes the "ancient astronaut" hypothesis. It was first popularized by Erik von Daniken in the late 1960s, and perpetuated by the likes of Zechariah Sitchin in recent decades. Neither of these individuals had the training or expertise to attack the research problems they claimed to have pursued to their correct ends. Shoddy work all around.
Sitchin claimed to be adept in reading ancient Sumerian and other ancient Near Eastern languages, but never produced his credentials--ever--to anyone. His contentions, while interesting, are so much bunk when held under the lens of scholastic scrutiny.
Were we "visited" in the prehistoric past? Yes. Were they the aliens that von Daniken, Sitchin, and their ilk claim? No--something much worse.
For a thorough and excellent treatise on the embarassing shortcomings of Sitchin, click the link below. Dr. Michael Heiser wrote an open letter to Sitchin asking him to produce his credentials and support his linguistic arguments. Sitchin never answered but now one of his followers has. Read Heiser's (who is a well-respected Semitic Language scholar) remarks in black and the yellow notes, and the Sitchinite's feeble attempts in red.