Why Do Stars Shine?

Stars shine because they are constantly cooking themselves! Imagine a star like a giant kitchen pot. Deep inside the core, tiny particles called protons crash into each other so hard that they stick together to form helium. When this happens, they release a tiny bit of extra energy as light and heat.

This process is called fusion. It takes billions of years for a star to run out of fuel. Right now, our Sun is doing exactly this. It has been shining for about 4.5 billion years and will keep going for another 5 billion years! The light we see at night is just the surface of that giant cooking pot glowing.

Wood burns by reacting with oxygen, but stars do not need air. They cook their own fuel. This is why stars can shine in the vacuum of space where there is no air. The pressure inside a star is like a giant hand squeezing the gas until it ignites naturally.