A strange spiral cloud that resembles a jet's vapour trail has left experts baffled.

Nobody can work out how the trail was formed, with the mist seeming to billow in from an MoD testing range near Stonehenge.

University weather experts and MoD officials have all been left scratching their heads while trying to work out what the mist is.

The incredible photo was taken by David Hargrave, from Sidbury Hill on Salisbury Plain, on Tuesday night.

University weather experts and MoD officials have all been left scratching their heads while trying to work out what this spiral cloud is

He was walking his dogs when he noticed the vapour trail, which also looks like the aftermath of a rocket launch.

It appeared to have been tainted red by the setting sun.

David said it was about 30 miles west of where he was, in the direction of Westbury at the north-western edge of Salisbury Plain.

Land nearby is an MoD testing range where heavy weapons are trialled and soldiers regularly train.

Calls to the University of Bristol and Somerset Drone experts Atticus have been made, but no one is any wiser as to what exactly it was.

The Defence Infrastructure Organisation, part of the MoD which operates the plains is not aware of any military training which could have caused it.

Mr Hargrave, 66, said he had never seen anything like it, adding: ‘I haven’t got a clue what it is either — hopefully someone out there will have an answer. It is a mystery.’