What's it all about? -- The spiral at National Museum of the American Indian

I got a majorly rapid response from NMAI regarding my question about the spiral outside the NMAI that I talked about in my post yesterday. I've pasted the reply below. Pretty cool, huh? Oddly enough, I've actually watched a documentary about Chaco Canyon and how the people who lived there attained incredible understanding about the moon cycles. Very interesting and impressive.

HI Lori

   The spiral you are referring to actually represents the major lunar standstills-periods of extreme daily and monthly moonrise and moonset patterns that occur every 19 years.  It is modeled after the Chaco Canyon’s ancient sundial  that recorded the moon and sun positions at different points of the year. 

  The symbol also shows example of balance throughout our museum’s landscape.  If you noticed our front entrance has sun symbols (because we face the east) and the south entrance where the spiral is shows the moon.  In some Native cultures (i.e. my Quechua ancestors) the sun is a male form and the moon is a female form (Inti-the sun…Killa-the moon).

I hope this helps you out in understanding the many symbols throughout our building. 

Thanks!

Vanessa