An unusual rainbow fan was captured in Presenzano, Italy, last week at sunset, appearing as an incomplete rainbow in a sunlit fan while hanging up laundry.
What makes the phenomenon most unusual is the apparent location of the Sun. The Sun appears to be toward the front, just below those hills, but that is not how rainbows work.
Rainbows involve a backward reflection from falling rain, which requires the Sun to actually be behind the observer.
In this case, gaps between clouds near the setting Sun allowed rays to cross the entire sky and appear to converge in front, creating an unusual phenomenon called anticrepuscular rays.
The photo was taken with a phone on October 20, 2026, and credited to Aurelia Degli Esposti.
The Astronomy Picture of the Day is edited by Robert Nemiroff, Jerry Bonnell, Cecilia Chirenti, and Keighley Rockcliffe, and is a service of ASD at NASA / GSFC, NASA Science Activation, and Michigan Tech.
