It is probably the most infamous radio broadcast of all time: Orson Welles’ Halloween 1938 dramatisation of H.G. Wells’ “The War of the Worlds”.
Welles transplanted the story from England to Grover’s Mill, New Jersey, and told it as a series of news reports, keeping the tension and hysteria of it all steadily rising. It terrified audiences at the time – like a hell of a lot of Welles’ work it is arguably a great work of art, and an enormous prank at once.
Whether or not there was panic during the broadcast, there was considerable outrage afterwards – how that has to do with the alleged ‘cruelty’ of it, and how much with people just hating to be fooled is an open question.
Radio GaGa – Queen
Alternately, it is possible that aliens did blast through from the Eighth Dimension, and hypnotise Welles into covering it up. But if so, I’m sure Buckaroo Banzai will sort it out.