Galactic Visitor, Or Greenhouse Reflection?

The BBC says a commercial airline pilot reported seeing two unidentified flying objects in the sky near Guernsey.

The pilot reportedly estimated the bright yellow flat discs were twice the size of a Boeing 737, and spotted them Monday, 12 to 15 miles north east of the island.

"This is not something you see every day of the week -- it was pretty scary," pilot Ray Bowyer said, adding he originally thought the sun was reflecting off greenhouses in Guernsey.

John Spencer, deputy chairman of the British UFO Research Association, says pilot UFO sightings have been reported since the 1940s, and generate excitement because pilots are trained observers. In Monday's case, the sightings were verified by passengers and other pilots in the area.

Of course, many UFO sightings are later dismissed as misidentified aircraft, weather balloons, or unknown natural phenomena. Britain's Ministry of Defense says it will not be carrying out an investigation in this particular case.

Still, Spencer tells the BBC you can't just dismiss them all.

"Such light effects are often popularly thought to represent alien visitors but many UFO researchers believe they more likely represent natural, atmospheric, phenomena not yet fully understood by science," he said.

"However, a similar encounter in 1978 over the Bass Straits in Australia, where the pilot was in radio contact with the ground throughout, resulted in the pilot never being heard from again, so these phenomena are important to study."