CNN — The hauntingly spectacular Crab Nebula, nearly 6,000 light-years away, is releasing an incredible amount of energy. (One light year is six trillion miles.)
The nebula is six light-years wide, and it’s a growing cloud of debris formed from a supernova explosion, which is what happens when a star blows up. The light produced by the supernova first reached Earth in July 1054 and was witnessed by astronomers in Japan and China.
When the star exploded, it formed a neutron star, which is the dense core of a star that is about the size of a city like Chicago. This started to spin...