Among the oldest stars in the universe, a chemical mystery has persisted for decades: strontium appears in quantities that nuclear theory could not explain. An international team of physicists has now measured, for the first time, how the isotope krypton-88 captures neutrons under stellar conditions, discovering the rate is lower than models assumed — a correction that, when applied to simulations, finally brings theory into agreement with what astronomers observe. The finding does not close the book on stellar element formation, but it turns a stubborn page, clearing the way for deeper questi