Astronomers just watched a star explode – and saw its insides exposed. For the first time in history, scientists got a direct look inside a star at the moment it went supernova – revealing inner layers that had, until now, only existed in theory. A massive star 2.2 billion light-years away reached the end of its life and exploded in a brilliant burst of light. But something was off. When researchers analyzed the spectrum of light from the explosion, they didn’t see the usual lighter elements lik

5 types of nebulae explained simply. | Cosmoknowledge