Artists use local radio and Twitter in Halloween hoax
Artists in Merseyside used a local radio broadcast and social media as part of a Halloween hoax.
Red lasers and search lights were projected across the night sky as part of the Romeo Echo Delta art experiment.
Realistic reports on BBC Radio Merseyside and comments posted on Twitter created speculation of an alien attack.
The event was part of an experiment by the Foundation for Art and Creative Technology (FACT) in Liverpool.
Artists Iain Forsyth and Jane Pollard said they were inspired by the impact of broadcasts such as Orson Welles' War of the Worlds War radio drama and the BBC's Halloween spoof Ghostwatch.
Ms Pollard said: "Historical cases of hysteria and civil disturbance really peaked our attention.
"Recently we have watched the news play out on Twitter... for example the deaths of Michael Jackson and Amy Winehouse.
"They really stood out because the news these days breaks so quickly online. You find yourself observing this kind of weird period where something has happened but nobody knows anything."
The project involved shining a 21-watt red laser beam across the River Mersey.
Search lights were also shone into the sky so that people listening to the radio could see what was happening and join in with the online speculation.
"What starts as an innocent comment or use of a particular word can snowball and be amplified to being almost fact," Ms Pollard said.
"This is a technique we used in Radio Echo Delta. There are some wonderful bits where the presenters are talking to a caller who says there are white trucks heading towards the light.
"The presenter says "unmarked trucks?" and it suddenly takes on a more sinister significance."
"We don't really want to fool people and have been very clear that it is a drama." Ms Pollard said.
"It is about offering an interesting suspended moment of not quite knowing what is going on and the potential for it to be something other worldly or dangerous.
"It is lovely to be part of the great BBC tradition of Halloween hoaxes.
"Like a great film to TV drama, we want people to be swept up."