Every second, the Sun converts 600 million tons of hydrogen into helium.

The Sun generates energy through a process called stellar nucleosynthesis, specifically the proton-proton chain reaction. In the core, temperatures reach approximately 15 million degrees Celsius (27 million degrees Fahrenheit) with pressures 250 billion times greater than Earth's atmosphere. These extreme conditions force hydrogen nuclei to overcome their natural repulsion and fuse together.Every single second, the Sun fuses roughly 600 million metric tons of hydrogen into 596 million tons of helium. The missing 4 million tons of matter are not lost but are converted into energy according to Albert Einstein's famous equation, E=mc². This formula demonstrates that even a tiny amount of mass can produce a staggering amount of energy because the speed of light squared is such a massive multiplier.The energy released travels from the core through the radiative and convective zones, eventually reaching the photosphere. It takes tens of thousands of years for a photon created in the core to reach the Sun's surface. Once it breaks free, it travels across space at the speed of light, reaching Earth in about 8 minutes and 20 seconds.This constant outward flow of energy, known as radiation pressure, is what maintains hydrostatic equilibrium. This balance ensures the Sun does not collapse inward due to its own immense gravitational pull. NASA's Solar Dynamics Observatory and the ESA's SOHO spacecraft continue to monitor these solar processes to help scientists understand the life cycle of stars.