sentences:  In 2019 the Crab Nebula was observed to emit gamma rays in excess of 100 TeV, making it the first identified source beyond 100 TeV.In visible light, the Crab Nebula consists of a broadly oval-shaped mass of filaments, about 6 arcminutes long and 4 arcminutes wide (by comparison, the full moon is 30 arcminutes across) surrounding a diffuse blue central region.In three dimensions, the nebula is thought to be shaped either like an oblate spheroid (estimated as away) or a prolate spheroid (estimated as away).