“An inscription tells us that the modern period will end December 24, 2011 A.D. We may presume that they [the aliens] were computing the length of a space voyage and marking the exact date of return. They may return to seek the fate of the colony left on earth. Perhaps at Uxmal they will find answers we have never been able to divine.”
This date was based on one interpretation of the Mayan calendar cycle (modern New Agers prefer December 21, 2012 as the end of the current cycle). But at any rate, given that Landsburg and Serling assert point blank that the “aliens” were planning to return last Saturday, we can be fairly confident that yet another strain of the ancient astronaut theory can be shown to be nothing more than so much numerological bunk.
Clearly, the aliens have not returned, and there is no evidence whatsoever that the cycles of the Mayan calendar have anything to do with the length of a space voyage, or that there was a “colony” of aliens at Uxmal—something that would be rather difficult since Uxmal was only founded in 500 CE, thousands of years after the “aliens” supposedly arrived to genetically engineer humans in Mesopotamia. Even Columbus managed to cross the Atlantic a bit faster than these aliens.