What appears to be a mysterious missile launched over the Pacific Ocean off the southern California coast Monday night may have merely been an ordinary aircraft contrail seen from an odd angle.

Dramatic video of the missile streaking into the sky near Los Angeles was captured by a television news helicopter cameraman and widely studied [See Video Below]. U.S. Navy and Air Force officials have denied that they launched any missiles in the area at the time, and said they are investigating the incident. The Internet was soon abuzz with conspiracy theories about who might have launched the missile, and for what purpose.

But there may be no "missile" to explain, or find.

In a blog Robert Sheaffer, a longtime skeptical UFO investigator and author of "UFO Sightings," notes, "As surprising as it may sound, the object seems to have been simply an aircraft contrail, with tricks of perspective making it look like a missile flying away from you, when in fact it was an aircraft flying toward you. It depends on an effect of perspective. The aircraft's path must be directly toward, or away from, the observer."

Contrails, or condensation trails, are created when moisture condenses around jet exhaust.

Sheaffer went on to write, "Second, even though the contrail is five miles above the ground, as it recedes into the distance it appears to touch the ground, because of the curvature of the Earth. As shown by the daytime photo of the vertical contrail on ContrailScience.com, we know that the aircraft that made it was not flying straight up like a rocket, but when seen directly straight-on, that is what it looks like. And for viewers a few miles away, getting a different perspective, all they see is an ordinary-looking slanted contrail."

This would explain many aspects of the "mystery missile" sighting, including the fact that according to the Federal Aviation Administration, radar in the area did not reveal any fast-moving unidentified targets. Furthermore, pilots in the area did not report any unusual sightings, which would make sense, since from their perspective the jet's contrail would not appear strange.

Furthermore, Sheaffer notes, this is not the first time that a contrail has been mistaken for a missile launch; an identical missile-like jet contrail was reported south of Los Angeles nearly a year ago, on Dec. 31, 2009.

And in 2003, NASA scientists were fooled by a likely jet contrail they first pegged as a meteor fireball hurtling into Earth's atmosphere – that photo also made the Internet rounds.

Benjamin Radford is managing editor of Skeptical Inquirer science magazine and author of Scientific Paranormal Investigation: How to Solve Unexplained Mysteries. His Web site is www.RadfordBooks.com.