Scientists just recreated a rare cosmic reaction never seen before

A breakthrough experiment has shed new light on one of astrophysics’ biggest mysteries: the origin of rare proton-rich elements. For the first time, scientists directly measured a key reaction that creates selenium-74 using a rare isotope beam. The results sharpen models of how these elements form in supernova explosions, cutting uncertainty in half. But the findings also reveal gaps in current theories, hinting that the story isn’t complete yet.