A series of brightly lit, rapidly moving objects filmed in the skies over Mexico (search) could have been caused by a scientific phenomenon involving gases in the atmosphere, a scientist said Thursday.

Visible only with infrared equipment, the hauntingly fast-moving lights were captured by air force cameras on March 5 but made public only this week, sparking rampant speculation they were flying saucers.

Julio Herrera, a nuclear science researcher at the National Autonomous University (search), said the bright blurs could have been caused by electrical flashes emitted spontaneously by the atmosphere.

"They are very strange phenomenon and there is little information about them," Herrera said of the atmospheric flashes in a phone interview. "That's what's so interesting."

He said more data than is available on the videotape would be necessary to determine if that hypothesis was correct, including precise information on atmospheric conditions at the time the lights appeared.

The Campeche coast on the Gulf of Mexico (search), where the objects were filmed, is Mexico's main oil and gas producing region. Oil platforms there release or burn off some of the gas they produce.

The objects were recorded flying at more than 11,000 feet over southern Campeche state (search) using a video camera equipped with an infrared lens. Infrared equipment can only detect heat emanating from objects; it is unable to provide an image of the objects' exact form.

"As far as public opinion goes, it's much more interesting to believe in fantasy, and for us it's the opposite," Herrera said, adding that he and other scientists are working to "try to determine a rational explanation for all this."

In the videotape, first aired publicly on national television Monday night, the objects appear to accelerate rapidly and change course suddenly. At least one crew member testified that the objects surrounded the air force jet when they were at least two miles away.

The pilots sighted the objects as they conducted a routine drug-surveillance mission.

Defense Secretary Ricardo Vega Garcia has said the military has yet to conclude what its pilots captured on tape.

Vega Garcia gave the tape to UFO specialist Jaime Maussan, who has spent 10 years studying unidentified flying objects. Maussan immediately concluded the video was evidence of the existence of UFOs (search).

"This is historic news," he told reporters Tuesday. "Hundreds of videos [of UFOs] exist, but none had the backing of the armed forces of any country. ... The armed forces don't perpetuate frauds."