Missle Launch, Optical Illusion, or Escape from California?

The Pentagon doesn't know where that missle came from that was photographed off the coast of Los Angeles Monday evening. It might not even be a missle.

Video posted on the CBS News website shows an object flying through the evening sky Monday that left a large contrail, or vapor trail. A news helicopter owned by KCBS, a CBS affiliate in Los Angeles, shot the video.

Pentagon officials were stumped by the event. "Nobody within the Department of Defense that we've reached out to has been able to explain what this contrail is, where it came from," Pentagon spokesman Col. Dave Lapan said.

One expert called it an optical illusion. "It's an airplane that is heading toward the camera and the contrail is illuminated by the setting sun," said John Pike, director of the U.S.-based security analyst group globalsecurity.org.

The North American Aerospace Defense Command, or NORAD, issued a statement jointly with the U.S. Northern Command, or NORTHCOM, saying that the contrail was not the result of a foreign military launching a missile. It provided no details.