A red spiral of sunlight appeared Wednesday morning on a wall inside the Fort Lewis College Center of Southwest Studies.
The spiral is the result of sunlight passing through a specially designed window that displays a complete spiral on the summer solstice, when the northern hemisphere tilts 23.4 degrees toward the sun before wobbling the other direction, giving the southern hemisphere preference for more daylight.
The red hue was the result of diffused smoke in the atmosphere from a wildfire near Santa Fe, New Mexico.
The last time a red spiral appeared was in 2002, the year of the Missionary Ridge Fire, which burned more than 70,000 acres north of Durango and west through Vallecito, said Jeannie Brako, curator at Center of Southwest Studies.
The spiral appeared suddenly at 6:29 a.m., and then faded in and out for about 20 minutes. It usually shows up a few days around the solstice and burns a bright white, sharpest on the day of the solstice.