Delving into the past with Chris Hallam.

The evening of October 30, 1938, would never be forgotten.

For it was on that fateful night, that American radio audiences first learnt that the planet was under attack from an invading alien army from the planet Mars.

“I'm speaking from the roof of the Broadcasting Building, New York City,” the voice of the announcer solemnly revealed.

”The bells you hear are ringing to warn the people to evacuate the city as the Martians approach.”

Listeners were warned about mysterious lights in the sky and earthquakes caused by the impact of the Martian spacecraft falling to Earth.

Americans were warned that parts of New Jersey had been devastated by the Martians’ use of a lethal heat ray which could incinerate people within seconds.

Terrifying first-hand accounts of the Martian onslaught were read out on air.

Of course, we now know no such invasion ever occurred. The radio broadcast was, in fact, not a news programme at all but a vivid radio dramatization of H.G. Wells’ 1898 novel, The War of the Worlds.

The dramatization was nevertheless so convincing that thousands of listeners seem to have believed it was a real.

There were reports of widespread panic. It was said people had heart attacks as a result, others claimed to have literally 'seen' the Martian invaders for themselves.

Rumours spread like wildfire. Bizarrely, some people seemed to believe the invaders were not Martians at all but were communists, Nazis or Japanese soldiers, even though no reference had been made to any of these groups during the show.

The production had been the brainchild of young Orson Welles, who wrote, directed and narrated it.

The 23-year-old Welles was no relation to the British author, H.G. Wells despite their similar surnames but was nevertheless already a rising star.

Welles was known for his radical theatre work with the Mercury Theatre.

Amongst other things, he had directed a Shakespeare play with an entirely black cast: a radical and provocative idea in the U.S. at the time. He was also the voice of the popular 1930s radio hero, The Shadow, a role he performed anonymously.

Listening today, it is easy to see how listeners might have been fooled into thinking the Martian invasion was real.

Although the programme was clearly introduced as the latest in a regular series of entertainments from the Mercury Theatre, anyone who turned on their radio after the start would have missed that.

The programme also cleverly took the form of a live concert performance of classical music which was periodically interrupted by Welles’ increasingly alarming fictional news broadcasts as if the invasion was happening live.

There was, of course, no internet and few other means for people to verify whether what they were listening to was really happening or not. It is arguable, of course, that the existence of Facebook and Twitter might have made things even worse.

The use of real-life place names such as Grover’s Mill, New Jersey added to the sense of authenticity.

Orson Welles always denied intending to hoax the general public and grew increasingly alarmed as he witnessed large numbers of police officers entering the radio studio as he delivered the closing stages of the live broadcast.

He quickly grew terrified that he was in serious trouble and would be ruined. In fact, the controversy was the making of him.

He became a household name and would be a famous actor, writer and director on both film and TV for the next fifty years.

One man who was not impressed, however, was the ageing British author, H.G. Wells: the man who written the novel of The War of the Worlds in the first place.

But even he changed his tune after meeting the young Orson Welles himself and realising the resulting publicity would lead to a dramatic increase in sales of his book.

At any rate, it was a night which no one would forget in a hurry.