The Crab Nebula from CFHT . ... Credit Copyright: Canada-France-Hawaii Telescope , J.-C. Cuillandre ( CFHT ), Coelum Explanation: This is the mess that is left when a star explodes. The Crab Nebula , the result of a supernova seen in 1054 AD , is filled with mysterious filaments. ... In the nebula's very center lies a pulsar : a neutron star as massive as the Sun but with only the size of a small town . ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...