Rainbows are universally welcomed weather-related phenomenon, colorful symbols of joy and hope. But have you ever encountered their nighttime cousin, the moonbow?

Created by the light of the moon being refracted through water droplets in the air, these rarities can be found at places like Corbin, Kentucky’s Cumberland Falls State Resort Park—one of the few places in the world where they appear regularly—and Yosemite in California. Bring your camera, though, for the full experience; the human eye often sees moonbows as white-gray, but cameras can usually capture their colorful prism.