Sun Is Actually White

From our vantage point on a summer's day, it's easy to see our sun as a brilliant yellow orb. This familiar color, however, is a clever trick played by Earth's atmosphere. The scientific principle at work is called Rayleigh scattering, where the gases and particles in our air are more effective at scattering short-wavelength light, like blue and violet. This very process is what paints our sky blue; the scattered blue light reaches our eyes from all directions. The direct sunlight that gets through this atmospheric filter is therefore missing some of its blue components, causing our star to appear yellowish.

Outside this filter, in the vacuum of space, the sun's true color is revealed. It is a brilliant, pure white. This is because it radiates intensely across all wavelengths of the visible spectrum, and when our eyes perceive all these colors at once, the signal is interpreted as white. Astronauts aboard the International Space Station see this directly, and their photographs confirm that our star is not yellow, but a dazzling white.

This same atmospheric scattering effect is also responsible for the dramatic colors of sunrise and sunset. When the sun is low on the horizon, its light must travel through much more of the atmosphere to reach us. This scatters away not only the blue light but also greens and even yellows, leaving behind the stunning reds and oranges that signal the end of the day.