Rainbows are often seen when the sun comes out after or during a rainstorm. Rainbows are caused when sunlight shines through drops of water in the sky at specific angles. When white sunlight enters a raindrop, it exits the raindrop a different color. When light exits lots of different raindrops at different angles, it produces the red, orange, yellow, green, blue, indigo, and violet that you see in a rainbow. Together, these colors are known as the spectrum. These colors can sometimes be seen in waterfalls and fountains as well.

Did you know that there are double rainbows? In a double rainbow, light reflects twice inside water droplets and forms two arcs. In most double rainbows, the colors of the top arc are opposite from those in the bottom arc. In other words, the order of colors starts with purple on top and ends with the red on bottom. In addition, rainbows sometimes appear as white arcs at night. These rainbows are called moonbows and are so rare that very few people will ever see one. Moonbows are caused by moonlight (rather than sunlight) shining through drops of water.