It may have taken 48 hours, but the Defense Department is now saying that it was an airplane and, crucially, not a missile that left a mysterious vapor trail off the coast of Southern California.
Pentagon spokesman Dave Lapan said: 'There is no evidence to suggest that this is anything else other than a condensation trail from an aircraft.'
Colonel Lapan reiterated that there was no threat to America.
The video of what looks like the contrail of a missile was shot on Monday evening by KCBS cameraman Gil Leyvas from a news helicopter over Los Angeles.
Mysterious: Authorities have been left baffled as to what the phenomenon was off the Southern California on Monday. It certainly looked like a missile launch
obviously an airplane contrail... There's a reason that they're called rockets.
Off the coast: The location of the missile was said to be west of Los Angeles, north of Catalina Island, and approximately 35 miles out to sea
He said the object was moving too slow to be a missile, and footage showed light of varying intensity coming from the object, which suggested reflected light from the sun rather than light generated from an engine.
Not ours: Vandenberg Air Force based confirmed they launched a Delta II rocket on Friday but was not responsible for yesterday's missile
Plane crazy: The missile launch appeared to get close to an aircraft from nearby LAX airport. But many now believe it was the result of a rare optical illusion
Colonel Lapan said an official missile test would usually involve air space being closed off and a notification to all shipping in the area. But there was no advance notice of the event.
KCBS-TV cameraman Mr Leyvas said he was aboard the station's helicopter shooting footage of the sunset over the ocean at 5.15pm when he noticed a spiral-shaped vapor trail and zoomed in to get a better look.
The on-board camera appeared to show a plume twisting up from the horizon and narrowing as it 'climbed' into the sky.
He said 'Whatever it was, it was spinning up into the sky kind of like a spiral. It was quite a sight to see. It was spectacular.'
And he wasn't the only one to see it. When Kelly Spear looked out the back window of her San Pedro home to see a rising orange line on the horizon, she thought it might be a rocket launch from Vandenberg Air Force Base.
She said: 'I told myself it was just a plane, but I really had no idea. We have a pretty expansive view, and I've never seen anything like that before.'
