On October 30th 1938, film director Orson Welles broadcast a radio adaptation of H.G. Wells's scientific romance (what would be called science fiction these days) The War of The Worlds for The Mercury Theatre on the Air.

The War of the Worlds depicted an alien invasion by Martians of the planet Earth, and is probably one of the more significant science fiction novels of all time. Welles's radio version of it is reputed to have brought panic to the streets when the events being referred to were mistakenly taken as being factual, relating to an actual alien invasion, rather than fictional.

Supposedly, many listeners tuned in having missed all the notices about the broadcast being a work of fiction.

Image: By Acme News Photos (eBay front back) [Public domain], via Wikimedia Commons (commons.wikimedia.org/wiki/File:Orson_Welles_War_of_the_Worlds_1938.jpg)