A moonbow, also known as a lunar rainbow, is a rare optical phenomenon created when moonlight is reflected and refracted by water droplets in the air. Unlike regular rainbows, moonbows appear much fainter and often look white to the human eye, though cameras can capture their true colors.
Moonbows only form under specific conditions:
- The moon must be nearly full and bright
- The moon must be low in the sky (42 degrees or lower)
- The sky must be very dark
- There must be water droplets in the air opposite the moon
Common places to spot moonbows include near waterfalls at night or during light rain when the moon is bright. Famous locations for viewing moonbows include Cumberland Falls in Kentucky and Victoria Falls in Africa.