A rainbow is a beautiful natural phenomenon that fascinates us all. It occurs when sunlight hits water droplets in the air. How is a rainbow created? Imagine that sunlight is a mixture of all colors in the visible spectrum. When a ray of light hits a drop of water, the following happens: Refraction: The light penetrates the drop and is refracted. It splits into its individual colors, similar to a prism. Reflection: The split colors are reflected on the inside of the water drop. Refraction again: The light leaves the drop and is refracted again, making the colors visible to us. We see a rainbow because the different colors are refracted at slightly different angles, causing them to appear as a colorful arc in the sky. Secondary and double rainbows Sometimes you'll also see a second, fainter rainbow above the first. This is a secondary rainbow. It occurs when the light within the water drop is reflected twice. The colors are arranged the other way around, i.e. from the outside to the inside: violet, blue, green, yellow, orange, red. Important facts Shape: A rainbow is actually a whole circle, but we usually only see an arc because the horizon obscures the lower part. When you look out of an airplane, you can sometimes see a complete circle. Location: You always see a rainbow in the opposite direction to the sun. This means: the sun must be behind you and the rain in front of you. Every rainbow is unique: the exact position we see in the sky is slightly different for each viewer because it depends on our exact angle of view.