Air traffic controllers have been left stumped after a member of public photographed a strange plane contrail over Hampshire.
The shape of the trail looks to turn one way before quickly turning back again.
Teacher Florence Lehmann, spotted the trail as she left her home in Southsea at 7.20am on Monday. She told the Mirror: "It's really weird. It looks like the pilot sneezed or fell asleep.
"Somebody said a UFO had been spotted recently in the area and the pilot had tried to avoid it, which I quite like the sound of.
"There was no wind this morning and the plane actually moved trajectory."
According to Sky News, a spokeswoman for Nats, the air traffic control company, said she could not explain why the plane changed direction, saying: "Unfortunately Nats has no knowledge of the purpose of any given flight and we do not identify individual aircraft to members of the public."
Back in 2012, excited Texans believed they had been lucky enough to spot a flaming meteor shooting through the sky in San Antonio.
One local even described it as something he could now tick off his bucket list.
Bill Cooke, head of NASA's Meteoroid Environment Office, originally confirmed the footage as a bright meteor - but then said he believes it was a plane's contrail, or vapour trail.
According to the Daily Mail, he told Life's Little Mysteries: "Reviewing the video, it does appear to be a contrail."