Surely by now you've heard about the "mystery missile" that darted across the Southern California sky. Military officials and other federal authorities don't appear to have a clue as to what the flying object could have been. But some outside experts have a simple explanation for the uproar: What appeared to be a projectile spreading across the sky in the video was simply a contrail, the plume of smoke that airplanes typically leave in their wake.
(UPDATE: The Pentagon is now also saying that it was a plane.)
"This thing is so obviously an airplane contrail, and yet apparently all the king's horses and all the king's men can't find someone to stand up and say it," John Pike, a defense and aerospace expert, told the Washington Post's John Pomfret. Pike noted that the projectile was moving much slower than a missile would, adding that "there's a reason that they're called rockets."
Here's how Pomfret laid out Pike's case for the contrail theory:
It looked like a missile launch, he said, because of an optical illusion that made the contrail appear as though it started on the ground and zoomed straight up. In reality, he said, the contrail began on the horizon and ran parallel to the ground.
"It was an unusually clear day," he said. So what looked like a missile launch 35 miles off the coast of Los Angeles was actually the contrail of a jet that stretched 300 miles into the distance, he said. "At the end of the day, you really have to go with the simplest explanation," he added.
Pike is not alone in that assessment.
Harvard astronomer Jonathan McDowell told New Scientist that because a helicopter in flight recorded the video of the incident, it employed a visual angle that distorted the arc of the contrail. That effect was compounded, McDowell maintained, by the distinctive lighting of the sky at twilight -- and the net result was a bit of an optical illusion.
"What isn't clear to me is whether anyone but this helicopter saw it," McDowell said. "If it's coming over the horizon, straight at you, then it rises quickly above the horizon. You can't tell because it's so far away that it's getting closer to you -- you'd think it was just going vertically up."
In a blog post titled "It Ain't No Thing," arms control guru Jeffrey Lewis agreed: "The short explanation is that we don't see a lot of jet contrails head-on, especially from the vantage point of a helicopter. So, it looks like a missile to everyone else, including former Deputy Secretaries of Defense. But it probably isn't."
Nor, it seems, is this the first time that a jet contrail has triggered anxious speculation about a mystery in the heavens. There is, indeed, a website called Contrail Science devoted to explaining the visual quirks of contrails -- while debunking some of the wilder theories about what's going on up there.
[Related: Update on 'Balloon Boy' family]
It appears, in short, as though the "mystery missile" may amount to little more than a "Balloon Boy"-style cable non-story.
Of course, that doesn't mean that there will be any shortage of new conspiracy theories about the incident.