The sky is responsible for giving us the greatest phenomena, in the darkness of the night we can observe in its vault the movements of the stars and the dazzling meteor showers. But during the day, visual spectacles capable of astonishing anyone who allows themselves to look up also parade through it. Although serendipity must occur to look at some of them, like the mysterious iridescent clouds that stain the sky with colors with their visual poetry.
From time to time rainbows may appear in the sky, we are undoubtedly used to them. But it can also happen that vaporous clouds seem to intermingle with splashes of color, as if they themselves were transformed into rainbows. They are known as clouds and result from a beautiful optical phenomenon.
What are iridescent clouds and why do they occur?
Iridescents are a rare phenomenon, so when they appear they quickly become relevant among lovers of natural beauty. But there is behind this strange and ineffable natural phenomenon. The iridescence of clouds appears as a result of the diffraction of sunlight through the small droplets of, or even small crystals that make up the clouds. When the sun’s rays pass through the small droplets, the light is bent individually.
And although its iridescence can immediately take us back to a rainbow, it should be noted that it is not the same phenomenon that causes them. The rainbow appears thanks to the refraction of light that is broken down into a visible spectrum, which is why we always see the same seven colors in this phenomenon. Instead, iridescent clouds are more similar to what happens in puddles of water or gasoline.
Refraction and diffraction
When we talk about refraction, we refer to dispersion of light. But when we talk about diffraction, it refers rather to the deflection of the sun’s rays. For this reason, iridescent clouds usually appear in cloud formations that have a short lifespan, since the droplets are usually very small and have more opportunity to act as a new emitter that will deform the rays that pass through them. In other words, diffraction occurs when light passes through such a tiny obstacle (droplets) that it distorts the light waves. The result is a pattern of iridescent spots in the sky, usually behind clouds.
But when talking about nature, situations cannot be deterministic, so different types of iridescent clouds have appeared high above. Many of them appear pearly, while others look more like a rainbow. Whatever the case, all of them are extremely beautiful and exquisite to observe.