Yes, it is possible, though exceedingly rare, to see three rainbows at once.
While most people are familiar with seeing a primary and sometimes a secondary rainbow, the existence of a third, or tertiary, rainbow is far less common. According to the Optical Society of America, “Few people have ever claimed to see three rainbows arcing through the sky at once.”
Rarity of Tertiary Rainbows
The reason for the scarcity of tertiary rainbow sightings lies in the way rainbows form:
- Primary Rainbows: Created by single reflections of sunlight inside raindrops.
- Secondary Rainbows: Formed by two internal reflections, appearing fainter and in reverse color order compared to primary rainbows.
- Tertiary Rainbows: Result from three internal reflections within the raindrops. This process is much less common, and the resulting rainbows are extremely faint. They also appear in the same part of the sky as the sun, which makes it difficult to observe them without proper instruments.
Because the light becomes very dim and is reflected back towards the sun, tertiary rainbows are often difficult to see. The Optical Society of America also noted that "scientific reports of these tertiary rainbows were so rare that until now many scientists believed sightings were as fanciful as Leprechaun's gold at a rainbow's end." This highlights the extraordinary nature of witnessing a tertiary rainbow.
Key Points on Tertiary Rainbows:
- They are extremely rare due to the requirement of multiple light reflections.
- They appear very faint.
- They are located in the same direction of the sun, which makes them difficult to spot.
While the possibility exists, seeing three rainbows simultaneously is an incredibly rare and special phenomenon.
