The Southern Television broadcast interruption was a broadcast interruption through the Hannington transmitter of the Independent Broadcasting Authority in the United Kingdom at 5:10 PM on 26 November 1977. It is generally considered to be a hoax, but the identity of the intruder is unknown. http://en.wikipedia.org/wiki/Southern_Television_broadcast_interruption
The first discovery of the diffuse nebulous nature of the Orion Nebula is generally credited to French astronomer Nicolas-Claude Fabri de Peiresc, on 26 November 1610 when he made a record of observing it with a refracting telescope purchased by his patron Guillaume du Vair. http://en.wikipedia.org/wiki/Orion_Nebula#History