“The Sun is yellow”

Many of us grow up with the image of a bright yellow Sun, a depiction commonly seen in art, children's books, and even emojis. This pervasive visual representation, combined with our everyday observations, firmly embeds the idea of a yellow Sun in our minds. The Sun often appears yellowish or orange to us, especially when it is lower in the sky, reinforcing this common misconception.

However, the scientific truth is that the Sun actually emits white light, containing all wavelengths of the visible spectrum. This means that if you were to view the Sun from space, outside Earth's atmosphere, it would appear as a brilliant, pure white star. The light it produces is a blend of all the colors of the rainbow, which our eyes perceive as white.

The reason for the yellow or orange appearance from Earth's surface is due to a phenomenon called Rayleigh scattering. As sunlight travels through our atmosphere, it encounters tiny gas molecules like nitrogen and oxygen. These molecules are more effective at scattering shorter wavelengths of light, such as blue and violet, in all directions. This scattering is also why the sky appears blue.

When the shorter blue wavelengths are scattered away, the remaining light that reaches our eyes has a deficit of blue and appears more yellowish or even reddish, particularly when the Sun is low on the horizon. At sunrise and sunset, the sunlight has to pass through a much greater thickness of atmosphere, leading to even more blue light being scattered out, which is why we often see vibrant oranges and reds. So, while our atmosphere plays tricks on our perception, the Sun itself remains a dazzling white.