Science & history · Inside and above
Sunlight is old before it leaves the Sun
Energy made in the core does not fly straight out. It is absorbed and re-emitted over and over on its way up.
A slow escape
One NASA page says photons take some 250,000 years to work their way from the core to the visible surface. Another, a NASA visualisation, says a photon is absorbed and re-emitted over the course of 40,000 years.
Both are estimates of a random walk through gas that no one can watch, and they depend on the model of the Sun's interior used. What both agree on is the shape of the story: the escape takes thousands of years or more, and the last leg, from the surface to Earth, takes about eight minutes.
Sources
- NASA Five Weird Things That Happen in Outer Space (opens in a new tab) for photons take some 250,000 years to reach the surface · checked 2 October 2026
- NASA Scientific Visualization Studio Origin of Light (opens in a new tab) for a photon is absorbed and re-emitted over the course of 40,000 years · checked 2 October 2026