Before stars shine, they sleep in clouds.

Every star—including our Sun—begins life inside a nebula, a vast, cold cloud of gas and dust drifting through space. But this peaceful haze doesn’t stay quiet for long. Gravity starts pulling tiny particles together, forming clumps that grow heavier and hotter. When one of these clumps becomes dense enough, it turns into a spinning, glowing ball of gas: a protostar.

Then comes the spark.

At around 10 million degrees Celsius, hydrogen atoms in the core begin to fuse into helium—releasing an enormous burst of energy. That moment marks the birth of a star. From that point on, it shines, sometimes for billions of years.

It's the same process that lit our Sun—and every star you've ever wished upon.