The Crab Nebula is a supernova remnant located in the constellation Taurus. It was formed from the explosion of a massive star around 1,000 years ago, which was observed by humans in 1054 AD. The nebula is about 6,500 light-years away from Earth and is one of the most studied astronomical objects. The Crab Nebula contains a pulsar, known as the Crab Pulsar, which is a rapidly rotating neutron star that emits beams of radiation. This pulsar is responsible for the nebula's strong emission of X-rays and gamma rays. The nebula's intricate structure is composed of gas and dust, expanding outward from the explosion.