The celestial body at the center of our solar system is the Sun. It is a nearly perfect sphere of hot plasma, primarily composed of hydrogen and helium. The Sun accounts for about 99.86% of the total mass of the solar system, exerting a gravitational pull that keeps the planets, including Earth, in orbit. It serves as the primary source of energy for life on Earth through the process of nuclear fusion, where hydrogen atoms combine to form helium, releasing vast amounts of energy in the process. The Sun is vital for regulating our climate and supporting photosynthesis in plants.