XRISM’s high-precision X-ray data revealed unusually strong signatures of chlorine and potassium inside the Cassiopeia A supernova remnant. These levels are far higher than theoretical models predicted, showing that supernovae can be major sources of these life-critical elements. Researchers belie ve powerful mixing deep inside massive stars is responsible for the unexpected boost. The findings reshape our understanding of how the building blocks of planets and life were created. ...read more read less