Helikaudu

Helikaudu is a term derived from the Greek words "helios" meaning sun, and "kaudo" meaning tail. It refers to a phenomenon observed in the sky where a tail-like structure appears to extend from the sun, typically during sunrise or sunset. This optical illusion is caused by the scattering of light in the Earth's atmosphere, particularly by ice crystals in high-altitude clouds.

The helikaudu effect is most commonly seen in the form of a green flash, which occurs when the sun is near the horizon. As the sun dips below the horizon, the green light is refracted more than the other colors, creating a brief flash of green light at the edge of the sun's disk. This green flash is a result of the same atmospheric scattering that causes the helikaudu effect.

Helikaudu can also manifest as a red or orange flash, depending on the atmospheric conditions and the observer's location. These flashes are less common than the green flash but are still a fascinating example of the interplay between light and the Earth's atmosphere.

The helikaudu effect is a rare and ephemeral phenomenon, making it a subject of interest for astronomers, meteorologists, and sky watchers alike. It serves as a reminder of the complex and dynamic nature of our atmosphere and the intricate ways in which light interacts with it.