How does a moonbow form?

Moonlight bends and reflects in water droplets

Why do moonbows often look white to us?

Our eyes see little color in dim light

Why must the Moon be fairly low in the sky?

Like rainbows, the bow forms opposite a low light source

Moonbow Quiz: Lunar Rainbows Over Waterfalls After Dark

This moonbow quiz waits by a roaring waterfall on a bright full moon night. Play 10 interactive questions on how moonlight forms a rainbow in water droplets, why moonbows look white to our eyes, colors revealed in long-exposure photos, the need for a bright, low moon and dark skies, famous spots like Victoria Falls, Cumberland Falls and Yosemite, and where to look.

Start Moonbow Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

What
What is a moonbow?
How
How does a moonbow form?
White
Why do moonbows often look white to us?
Photo
How can people see a moonbow's colors?
Moon
When are moonbows most likely?
Low
Why must the Moon be fairly low in the sky?
Dark
Why are dark skies important?
Victoria
Which African waterfall is famous for moonbows?
Kentucky
Which US waterfall is known for regular moonbows?
Look
Where should you look for a moonbow?

Explanations: answer key for all 10 questions

Q1: What is a moonbow?
Answer: A rainbow made by moonlight
It is also called a lunar rainbow.
Q2: How does a moonbow form?
Answer: Moonlight bends and reflects in water droplets
It works like a sunlight rainbow.
Q3: Why do moonbows often look white to us?
Answer: Our eyes see little color in dim light
Rod cells dominate at night.
Q4: How can people see a moonbow's colors?
Answer: With long-exposure photos
Cameras gather more light.
Q5: When are moonbows most likely?
Answer: Near full moon
A bright moon is needed.
Q6: Why must the Moon be fairly low in the sky?
Answer: Like rainbows, the bow forms opposite a low light source
A high moon puts the bow below the horizon.
Q7: Why are dark skies important?
Answer: The moonbow is faint
City light washes it out.
Q8: Which African waterfall is famous for moonbows?
Answer: Victoria Falls
Night tours run at full moon.
Q9: Which US waterfall is known for regular moonbows?
Answer: Cumberland Falls
It is called the Niagara of the South.
Q10: Where should you look for a moonbow?
Answer: Opposite the Moon
Your shadow points toward it.

Rainbows by Moonlight

A moonbow, or lunar rainbow, forms when moonlight bends and reflects inside water droplets, just as sunlight makes a rainbow. Because moonlight is much fainter, moonbows often look white to our eyes, since in dim light our rod cells dominate and see little color. Long-exposure photos reveal the full rainbow colors.

Moonbows are most likely near full moon, when the Moon is bright. The Moon must be fairly low in the sky, because the bow forms opposite the light source, and the sky must be dark, since city light washes the faint bow out. To find one, look opposite the Moon, toward where your shadow points.

Waterfalls with constant spray are the best places. Victoria Falls in Africa runs night tours at full moon, Cumberland Falls in Kentucky, called the Niagara of the South, is known for regular moonbows, and Yosemite Falls shows them in spring.

What This Quiz Teaches

Sky fans will enjoy these questions.

What a moonbow is
How it forms
Why it looks white
When to see one
Where to look

Did You Know?

Moonbows also form in rain showers.
Mist from waves can create them.
Hawaii sometimes sees moonbows.
Spray makes cameras wet.
Clear nights after rain help.