• Luke

The start of Major Lunar Standstill season at Chimney Rock National Monument

This weekend I got to experience an astronomically amazing celestial phenomenon at Chimney Rock National Monument. I got to witness the moon rise between the chimney rocks for the first time ever in 18 years and was one of the few people to have ever observed this alignment in modern times.





Chimney Rock National Monument (located near Pagosa Springs Colorado) has been an enigma to archeologists for decades. The Monument consists of an archeological site (constructed by the ancestral puebloan people that used to inhabit the four corners region) and two geologic features (two pinnacles that make up the ‘chimney rock’ that tower over the archeological site). The geologic features were thought to be used as seasonal indicators by the ancestral puebloans, denoting the position of the sun, much like stonehenge was used to tell solstice/equinox. However, it never added up, the sun would never rise between the two pillars.







While studying the site archeologist looked at the tree rings of the wood used by the ancestral puebloans to build the structures. Comparing the tree rings of trees that are still standing to the ones used in the structures, archaeologists could tell when the wood was harvested and get an idea of when it was built. They noticed that building seemed to happen in 18 year periods showing that activity at chimney rock was on a periodic 18 year cycle. They took this finding to an astronomer and asked ‘what (if any) phenomenon happens in the sky every 18 years!?’ and the astronomer knew right away that it was a cycle of the moon not the sun, namely the ‘Major Lunar Standstill’.


Basically Major Lunar Standstill is an 18 year cycle of the moon where the moon moves to the northernmost position it will be in the sky. I have a blog post explaining it more here https://www.astrotours.org/post/major-lunar-standstill. In short; this means for the next ~3 years there will be plenty of opportunities to see the moon rise between the Chimney Rocks but after the last one occurs in September 2026 it won’t be seen again for another 18 years.





If you want to learn when and how to see the Major Lunar Standstill at chimney rock yourself I made a blog post here explaining that https://www.astrotours.org/post/how-to-see-major-lunar-standstill-at-chimney-rock-national-monument.


If you want to see the Major Lunar Standstill with me contact me https://www.astrotours.org/privatetours.


If you want to learn more about this and all the clockwork of our universe book an AstroTour in Boulder here https://www.astrotours.org/booking






180 views0 comments

Recent Posts

See All