There’s a certain amount of irony (iron-y?) that heavy fissionable materials are formed when fusion stalls: the core of a large star is turned into iron, fusio

There’s a certain amount of irony (iron-y?) that heavy fissionable materials are formed when fusion stalls: the core of a large star is turned into iron, fusion “goes out”, then the star collapses and goes supernova. Heavier elements are formed in the “bounce” when the outer layers of the star crush down the suddenly cold(er) core, converting the kinetic energy into reactions that absorb energy by fusing heavy elements. Or something along that line, anyway.