A DEVASTATING burst of gamma rays may have caused one of Earth’s worst mass extinctions, 443 million years ago. A team of astrophysicists and palaeontologists says the pattern of trilobite extinctions at that time resembles the expected effects of a nearby gamma-ray burst (GRB). Although other experts have greeted the idea with some scepticism, most agree that it deserves further investigation.
GRBs are the most powerful explosions known. As giant stars collapse into black holes at the end of their lives, they fire incredibly intense pulses of gamma rays from their poles that can be detected even from across…
