Have you ever wondered why the sky appears blue during the day but turns orange or red at sunset? The answer lies in how sunlight interacts with tiny molecules in Earth’s atmosphere. This phenomenon, known as Rayleigh scattering, helps explain some of the beautiful colors we see in the sky.
What Makes the Sky Blue?
Sunlight may look white, but it contains many colors, each with a different wavelength. When sunlight enters Earth’s atmosphere, it interacts with tiny molecules in the air. These molecules scatter shorter wavelengths of visible light, such as blue, more strongly than longer wavelengths, such as red. This process is called Rayleigh scattering.
Because blue light is scattered in many directions, we see it coming from across the sky. Violet light is scattered even more strongly, but the combination of sunlight’s spectrum, atmospheric effects, and the sensitivity of our eyes makes the sky appear predominantly blue.