Question 1 of 15
What causes a rainbow?
Why: Sunlight enters a droplet, reflects off the back, and refracts on exit.
Question 2 of 15
At what angle does a primary rainbow appear from the sun?
Why: The primary rainbow's arc is centered 42° from the antisolar point.
Question 3 of 15
What color is on the outer edge of a primary rainbow?
Why: Red on the outside, violet on the inside.
Question 4 of 15
What causes a double rainbow?
Why: The second bow forms from light reflecting twice inside droplets.
Question 5 of 15
Why do colors reverse in the secondary rainbow?
Why: Two reflections flip the geometry, so the secondary shows violet outside, red inside.
Question 6 of 15
What is a halo around the sun caused by?
Why: Hexagonal ice crystals refract light at 22°, creating the ring.
Question 7 of 15
What are sun dogs?
Why: Sun dogs (parhelia) form on either side of the sun via ice crystal refraction.
Question 8 of 15
What is a corona around the sun or moon caused by?
Why: Coronae form from diffraction around droplets, unlike halos which use refraction through crystals.
Question 9 of 15
What creates the blue color of the sky?
Why: Rayleigh scattering favors blue light, giving the sky its color.
Question 10 of 15
Why are sunsets red?
Why: Low sun angle means light traverses more atmosphere; short wavelengths scatter out, leaving red-orange.
Question 11 of 15
What is a green flash?
Why: Refraction and scattering can produce a fleeting green rim at sunset over a clear horizon.
Question 12 of 15
What is a sprite in atmospheric science?
Why: Sprites are brief red discharges in the mesosphere above thunderstorms.
Question 13 of 15
What are noctilucent clouds?
Why: Noctilucent clouds glow at high latitudes in summer twilight.
Question 14 of 15
Which planet has the most extreme atmospheric optics?
Why: Saturn's ring shadows and hexagonal storms are unmatched.
Question 15 of 15
What color would a rainbow be at night, under moonlight?
Why: Moonlight rainbows exist but usually appear white because moonlight is too dim to activate color receptors.