Conversation

1000 years ago, the people who lived at Chaco Canyon and the area around it knew about the 18.6 year lunar cycle, in which the rise/set position of the moon slowly moves between north and south.

This is a generational project - you need 3+ generations to confirm the pattern, or 56 years of tracking and comparison. Globally, humans might have known this since 2500BC!

Tonight is the END of the lunar cycle - the moon will be at the northern-most position of its cycle - aka the "lunastice".