On July 4th, 1054, observers in Japan and China recorded the appearance of a “guest star” so bright it remained visible for three weeks during the daytime and for two years at night. Today we know the new object was actually a supernova caused by a massive star running out of fuel, gravitationally collapsing, and violently ejecting most of its matter into space.
The explosion left behind a spinning neutron star, or pulsar, rotating with incredible precision 30 times a second and emitting enormous blasts of radiation across the entire electromagnetic spectrum. The colorful nebula we see today consists of hydrogen, helium, carbon, oxygen, nitrogen, and heavier elements created during the supernova and energized by that radiation.
In August 1758, French astronomer Charles Messier was hunting for comets but repeatedly distracted by bright, fuzzy blobs like the Crab Nebula. To avoid wasting time on these “nuisance” objects, Messier started compiling a catalog of about 100 clouds that definitely weren’t comets. The Crab Nebula is first on his list – Messier 1, or M1.
