Residents of Lafayette, Colo., reported seeing a "strange formation of lights" in the night sky last week, causing excitement among both locals and the UFO community. Two eyewitnesses, Leroy van der Vegt and his son Nick, even managed to videotape the strange encounter. Their short video clip has become a YouTube sensation, helping spur what Fox News called a "UFO frenzy" in Colorado.

The three strange, bright red lights did not blink, but were instead continuous. They hovered in the air, changed formation, and then moved northeast before fading away after a few minutes. Van der Vegt stated that while he doesn't necessarily think it was an extraterrestrial spacecraft, he's certain it was not a satellite, nor a man-made aircraft such as a helicopter or plane. "It was completely quiet. No noise at all," he said.

Another eyewitness, Lester Valdez, said "It was exactly something like that where you see an object and they all got into a pattern and they stood in a pattern, and they all moved in a direction and then they pretty much dropped and that was it," Valdez said. "I have never witnessed anything like that."

So what was it? Extraterrestrials? Secret military craft? Or something more mundane? Clues about this UFO's identity can be found in the video and eyewitness accounts, and suggest a very terrestrial origin.

First, the formation of the lights is consistent with independently moving objects, not fixed lights on an aircraft. As can be seen in the video and from eyewitnesses, they all moved in one direction together, stayed in more or less the same formation while in the same air currents, then drifted apart.

Second, Van der Vegt's statement that they were completely silent suggests that he is correct that the lights were not part of a man-made aircraft. This indicated that however the lights were moving, they were not being propelled by anything with an engine or motor. So the lights were likely floating, not moving under their own power.

What sort of lights would float in the night sky, drift apart, and then fade away after a few minutes?

Road flares tied to balloons.

The way the lights disappeared also supports the hoax theory. They did not zoom away at high speed, as one might expect from an aircraft. Nor did they all suddenly and mysteriously disappear. Instead, eyewitnesses reported that the red lights remained steady but then "faded away"—exactly as dying road flares would do. And isn't it interesting that red is the most common color of road flare? [The World's Greatest Hoaxes]

This is not the first time that people have been fooled by flares tied to balloons; identical sightings over Phoenix in 2008, and New Jersey a year later, were found to have been similar stunts.

It's not surprising that eyewitnesses could not identify the objects, since most people have not seen road flares tied to balloons in the night sky. There's no reason anyone would recognize it: The lights literally were nothing they had ever seen before — but not necessarily anything extraterrestrial. Of course it's also possible that aliens visited Colorado last week in a spacecraft that just happens to look like road flares tied to balloons ...

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.