Chicagohenge comes around twice a year: just after the spring equinox and right before the fall equinox. With the equinox just around the corner—it’s tomorrow!—this week is your first chance of the year to catch the dazzling effect in some Chicago streets.

The name “Chicagohenge” is a play on Stonehenge, the ancient stone monument in England that also interacts with the sun in some amazing ways. It’s the kind of interplay between nature and infrastructure we love to geek out about on The Rundown.

In this episode, host Erin Allen spaces out with Michelle Nichols, the Director of Public Observing at the Adler Planetarium.

This episode originally aired on September 22, 2023.