Explore how light travels through the layers of the sun.
The light that illuminates our planet is made deep inside the sun and takes some 40,000 years to travel through the sun’s layers. Particles of light form from atoms undergoing nuclear fusion in the sun’s innermost layer known as the core. The light then flows through the sun’s interior for millennia, slowly bubbling up like water in a boiling pot. It eventually bursts past the sun’s surface, called the photosphere, and rises into the solar atmosphere. Once in the atmosphere—made up of the chromosphere and corona—the light streams out through the solar system. Watch the video to see how light travels from the sun's interior to the surface.