(Photo courtesy of Ken Zoll)

This picture shows two concentric circles at the top of the shadow line in perfect alignment with one in the sun and one in the shadow in this pattern only on the equinox.

(Photo courtesy of Ken Zoll)

This is a similar image to the V Bar V photo but is bisected like this only on the equinox.

Our next story takes us back in time … to prehistoric times, that is. Prehistoric civilizations in the Southwest didn’t have iPhones to keep track of the hour or even a calendar with months and days of the year marked out.

They used the sun and the stars to track time. And that mattered a lot for their survival.

Tonight, Ken Zoll, the executive director of the Verde Valley Archaeology Center, will be talking about how prehistoric people in the Southwest used astronomy, and he joins me now.