As children, we were taught that rainbows form when water droplets in the atmosphere act like tiny prisms, bending and splitting sunlight. When there is enough water and sunlight, we are treated to a vibrant display of seven beautiful colors. However, the reality is much more complex, and according to the latest research, scientists have classified a total of 12 different types of rainbows.
When the Sun is low on the horizon, during sunset or sunrise, the rainbow is limited to just two colors: red and yellow.
Some rainbows also feature a secondary rainbow and an inverted version of the first due to light reflection. Occasionally, we may observe a dark band in the sky between two rainbows. At times, there are also light fringes at the top and bottom of the rainbow, known as supernumerary rainbows.
A double rainbow, with two arcs of color that are reversed inside each other.
When light travels a long distance through the atmosphere before reaching our eyes, some shorter wavelengths are scattered away. Ultimately, we may only see a lovely pinkish-red spot in the sky instead of the full spectrum of colors we usually expect.
For small water droplets, the rainbow appears as thin and small bands in the sky.
For many decades, rainbows have been classified based on the average size of the water droplets. However, relying solely on this criterion does not account for the diversity of rainbows we can observe in nature. By categorizing hundreds of rainbow photographs based on variations of six colors and the presence of additional fringes, a group of scientists concluded that there are a total of 12 different types of rainbows, including color-deficient rainbows, red-blue rainbows, yellow-orange rainbows, yellow-red rainbows, and monochromatic red rainbows, among others.
At sunset and sunrise, the rainbow appears as a band of red and yellow or orange.
Finally, researchers created a classification diagram for the types of rainbows observable in nature. For example, a special type of rainbow is the diffused red rainbow (featuring only red and yellow or orange), which occurs just as the Sun is setting or rising and when the atmosphere is filled with small water droplets. Indeed, a seemingly simple natural phenomenon like a rainbow holds many more fascinating aspects than we might imagine.
A pair of rainbows can be separated by a dark band in the sky.
