What makes a star explode?
Deep in the center of a star lives a nuclear reactor. It’s energy comes from the fusion of hydrogen atoms into helium atoms. These light-weight elements produce just the right amount of energy to support the star against its own gravity; it is a stable furnace, floating through space. When a star’s gas tank starts creeping toward E, it doesn’t sputter like a starving engine. The force of the nuclear reaction is too great. Instead, the star expands. As it grows larger, it begins to form heavier elements like iron and carbon. Once the last bit of fuel is finally burned up, the excitement begins. Without the hydrogen to helium reactions that counterbalanced the star’s tremendous gravity, the remaining mass collapses toward the center. Then, like a superball, the mass is bounced back out in a catastrophic explosion. The massive amount of heat, radiation, dense mass and strong gravity in a supernova is the source of all the heavy elements in the universe. The remnants of supernovae eventual
