The Pentagon is still not sure what that was in the sky off the coast of California -- except that it was not a missile fired by the U.S. or some other country, reports CBS News Pentagon correspondent David Martin.
The video of what looks for all the world like the contrail of a missile was shot Monday evening by KCBS cameraman Gil Leyvas from a news helicopter over Los Angeles.
"I saw a big plume coming up, rising from looked like beyond the horizon and it continued to grow," Leyvas said.
He zoomed his camera in and stayed on it for about 10 minutes. To him it looked like an incoming missile.
"It was unique. It was moving," he said. "It was growing in the sky."
The Pentagon spends billions of dollars a year making sure it is never surprised by a missile launch - so finding out what the camera saw became a top priority. Both the Navy and the Air Force insisted they had not launched any missiles and the North American Air Defense Command - which is supposed to track incoming missiles - declared it had not been fired by any other military. But nobody could say what it was.
But Doug Richardson, the editor of Jane's Missiles and Rockets, examined the video for the Times of London and said he was left with little doubt.
"It's a solid propellant missile," he told the Times. "You can tell from the efflux [smoke]."
Richardson said it could have been a ballistic missile launched from a submarine or an interceptor, the defensive anti-missile weapon used by Navy surface ships.
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The Twitterati had a field day Tuesday, tweeting comments like "Can someone please tell me how our Department of Defense has no idea who launched a missile from California's coast?"; "So nobody in our government or military knows? Scary."; and "If you misplaced a missile off the coast of California, the U.S. government would like to have a few words with you."
The Federal Aviation Administration did not receive any reports of a missile from other pilots in the area or track any unusually fast objects. The Air Defense Command determined the object was not traveling fast enough or have a big enough exhaust plume to be a military missile.
The best guess right now is that it was either an airliner or an amateur rocket, but we may never know for certain.