I loved this material until you mentioned Eric Van Daniken. I don't hold with much
credibility with him. I have also studied Mayan civilization and their calendar. This
talk of ancient astronauts doesn't hold much weight with me.
However, your discussion of the Mayans and their calendar I have interest in. I also
am interested in the Olmecs even though what little we know of them.
The neat thing about 54 years is that is exact amount of time of the Saros cycle of
the moon which is amount of time of the ascending node of moon's orbit around the
Earth to process around 360 degrees. Mayans calendar is and was better at predicting
the brightest/highest point for both Venus and Mars (though Venus was more
important).
Maddog