Many of us grow up drawing the sun with bold, cheerful rays in either yellow, orange, or red hues. It's a common impression — largely influenced by the vibrant colors of sunrises and sunsets, and the way sunlight can appear warm and golden during the early and late parts of the day. However, the true color of the sun is actually much closer to white than any of the colors typically associated with it.
The sun emits light at all wavelengths of the visible spectrum, which means it shines in every color from violet to red. When all these colors combine, they produce white light. This reality becomes evident when sunlight passes through a prism, which disperses the light into a spectrum of colors, a phenomenon Sir Isaac Newton famously used to demonstrate that white light is made up of various colors.
The reason the sun can appear yellow, orange, or red to us from Earth’s surface has much to do with our atmosphere. The shorter, bluer wavelengths of sunlight are scattered in every direction by air molecules and tiny particles in the Earth’s atmosphere, a process known as Rayleigh scattering. This is the phenomenon that gives the sky its blue color during the day. During sunrise and sunset, the sun’s light is passing through a greater thickness of Earth’s atmosphere than during the middle of the day, increasing the amount of scattering of the blue light, thus allowing the longer, warmer wavelengths to dominate our visual perception of the sun.
Moreover, various atmospheric conditions such as the presence of dust or pollution can enhance the scattering effect, making the sun appear even more red or orange than usual. However, if you were to view the sun from space, where there is no atmosphere to scatter its light, the sun would appear as it truly is: a bright white star. This understanding not only corrects a common misconception but also enriches our appreciation of our closest star and its interaction with our planet. Through this lens, the ever-changing colors of the sun become a dynamic and vivid demonstration of the fundamental principles of light and atmospheric science.
