21.1 Sun and Planetary Data
The Sun is the greatest source of light, heat, and other forms of electromagnetic waves. The gravitational pull of the Sun keeps the planets, including Earth, in orbit around it. The Sun is located at the centre of our solar system. It contains about 74% hydrogen and 24% helium, along with a few other elements.
Nuclear fusion takes place at the core of the Sun, where hydrogen atoms fuse together to form helium. This releases a tremendous amount of energy and raises the temperature of the Sun to millions of degrees Celsius. The energy released travels through space as infrared, visible, and ultraviolet radiation. This energy makes weather patterns, changes the climate, and supports ecosystems.