The Sun is not made of fire, its energy comes from nuclear fusion to its heart, where the temperature exceeds 15 million degrees and the pressure is immense. It melts hydrogen atoms, turning them into helium, releasing energy in the form of light and heat in the process.
Every second, it converts 600 million tonnes of hydrogen into 596 million tonnes of helium, the 4 million tonnes of missing matter is converted into energy - a process that will continue for the next 5 billion years.
