Zecharia Sitchin

Indeed, a number of popular writers have speculated that ancient artifacts such as the pyramids and giant stone sculptures must have been fashioned by advanced visitors from another planet -- for surely primitive man could not have possessed by himself the required technology? How was it, for another example, that the civilization of Sumer seemed to flower so suddenly nearly 6000 years ago without a precursor? But since these writers usually fail to show when, how, and, above all, from where such ancient astronauts did come -- their intriguing questions remain unanswered speculations.