A photon takes over 100,000 years to travel from the Sun's core to its surface, but only eight minutes to reach Earth.

Energy is generated in the Sun's core through nuclear fusion, where temperatures reach 15 million degrees Celsius. This process creates high-energy gamma rays that begin a journey through the Sun's radiative zone. Because the Sun is so incredibly dense, these photons cannot travel in a straight line. Instead, they undergo a 'random walk,' colliding with hydrogen and helium nuclei and being re-emitted in random directions.Calculations by solar physicists, including those at NASA, suggest this journey can take anywhere from 10,000 to 170,000 years depending on the specific path and density encountered. During these billions of collisions, the photons lose energy and transform from gamma rays into visible light. This process is essential because it prevents the Sun's core energy from escaping instantly, which would cause the star to explode.Once a photon reaches the photosphere, the Sun's visible surface, the environment becomes thin enough for the light to escape. It then enters the vacuum of space where it travels at the constant speed of approximately 186,282 miles per second. At this speed, it covers the average distance of 93 million miles to Earth in roughly 8 minutes and 20 seconds. This staggering contrast highlights how the Sun's internal structure acts as a massive physical barrier to light.