The provided text explores the dual nature of supernovae, highlighting their role as both creators of life's essential elements and potential destroyers of biospheres. It explains how these stellar explosions forge heavy elements crucial for planets and life, and may have even triggered the formation of our solar system. Conversely, the text details the two-stage destructive impact of nearby supernovae: an initial, fast burst of high-energy radiation that depletes the ozone layer, followed by a prolonged bombardment of cosmic rays that can cause widespread biological damage and climate shifts. Finally, the text presents forensic evidence, particularly Iron-60 deposits, linking past supernovae to Earth's geological record and discusses how these events may have contributed to mass extinctions, such as the Pliocene-Pleistocene marine megafauna extinction and the Late Devonian crisis.

Research done with the help of artificial intelligence, and presented by two AI-generated hosts.