The universe's first stars were extremely hot and incredibly large, often reaching hundreds of times the mass of the Sun. And because they formed just a few hundred million years after the Big Bang, these boiling behemoths contained virtually no elements heavier than hydrogen and helium, which were the only materials readily available at the time.
But due to their sizeable stature, the first stars also lived fast and died hard — lasting only a couple million years before they exploded as powerful supernovas. As these first stars quickly burned through their fuel, they forged lighter elements into heavier ones like carbon, iron, and zinc.
