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In La Vanguardia’s Readers’ Photos we can admire the geometric games in the sky of Granollers, in the Vallès Oriental, from the marked lines of the condensation trails to the perfect circumference drawn by the sun. All this with the colors of the candilazo.

Airplanes form a vapor trail after the kerosene combustion process. The gases expelled by the engine come out at a much higher temperature than the outside temperature.

The sharp contrast in temperatures at a height greater than 30,000 feet (-50 degrees in the atmosphere) causes the immediate condensation of the water present in this mixture of substances. This causes us to see these kinds of elongated ice clouds that dissipate after a few seconds.

This phenomenon is known in the Anglo-Saxon and aeronautical world as contrail – a word that comes from the fusion of the words condensation (trail) or in Spanish, condensation trail.

For its part, the candilazo is a meteorological phenomenon in which the clouds in the sky show a wide palette of colors that ranges from pink to the most intense orange.

As part of the phenomenon of dispersion of sunlight, in the morning and afternoon hours, when the sun is closer to the horizon, the light that reaches the Earth is soft tones between red and orange.

In a certain way, when this light passes through the clouds, it illuminates them and could be said to color them with those tones.

The candilazo is also known as arrebol, which is the red color seen in clouds illuminated by the sun’s rays, especially at dawn and in the evening.