What Makes the Sky Blue?

Why is the sky blue during the day?

What causes this natural phenomenon?

The sky appears blue during the day because...

Have you ever wondered why the sky is blue during the day? The answer lies in the way our atmosphere interacts with sunlight. When sunlight reaches Earth's atmosphere, it is composed of different colors, each with a different wavelength. Among these colors, blue has the shortest wavelength and is scattered more easily by the gases and particles in the air.

As sunlight enters Earth's atmosphere, the shorter blue wavelengths are scattered in all directions by the gases and particles, such as oxygen and nitrogen molecules. This scattering is known as Rayleigh scattering, named after the British scientist Lord Rayleigh who first described it in the 19th century.

When we look up at the sky during the day, we see this scattered blue light because it reaches our eyes from all directions. This is why the sky appears blue to us. In contrast, at sunset or sunrise, the sun is lower in the sky and the light must pass through a thicker layer of the atmosphere. This causes the shorter blue wavelengths to be scattered more, leaving the longer red wavelengths to dominate the sky's color palette, resulting in the beautiful colors of sunrise and sunset.