-The Crab Nebula is one example of a supernova remnant. In A.D. 1054, Chinese and Middle Eastern astronomers observed this supernova, as it appeared in the sky as a star brighter than Venus for a month. The Crab Nebula is still expanding at several thousand kilometers per second.

-Another supernova remnant is the Vela remnant. In about 9000 B.C., a supernova with the brightness of the moon lit the sky for many months. Supernovae this close to Earth 500 parsecs only happen every 100,000 years or so.

-Supernovas in our Milky Way galaxy only happen every 100 or more years.

-October 1604 was the last time a supernova was visible in our galaxy, Johannes Kepler made the oberservations