TWO UFOs narrowly avoided colliding with planes in the skies above East Grinstead.
The unexplained near misses have been seized on by extra-terrestrial enthusiasts as exciting new evidence of alien life.
But cynics are less convinced – and have suggested the unidentified flying objects, spotted by three pilots, were probably just kites or balloons.
The near misses have been revealed in a report by the Airprox Board, an independent body which aims to enhance air safety.
It reveals that three commercial airline pilots in separate planes witnessed "flat silver discs" hovering in the air, at about 1,500 feet, as the aircraft approached Gatwick Airport.
The sightings have sparked interest from UFO watchers around the world since details of them emerged last week.
But while the exact nature of the anomaly remains inconclusive, one former pilot believes there could be a disappointingly undramatic explanation.
Chris Mills, from Domewood, said: "My view is it was either a kite or balloon, and I think it was a radio-controlled model.
"Why there was two of them and why they would want to fly them right on the flightpath, I'm not sure.
"I thought they normally fly a lot lower than that, but that doesn't mean someone couldn't have modified it to go higher.
"I have flown about 20,000 hours over about 36 years, based mainly at Gatwick, and I've never come across anything like it before.
"They must have been up to mischief, because they flew right under the flightpath."
The "man-made" objects, spotted as the planes approached Gatwick from the east shortly before 9am on December 30 last year, were within 100 feet of the aircraft.
UFO expert Nick Pope said: "This is one of the most spectacular and intriguing UFO sightings that I have heard about in recent years.
"The evidence is first-rate; the witnesses are experienced pilots and, critically, there is radar evidence to back up their stories.
"None of the theories put forward to try to explain what happened hold water.
"Even the idea that these were secret prototype drones makes no sense, because such things are tested in remote areas, well away from busy flightpaths."
The UK Airprox Board compiles reports on near misses, where the distance between aircraft may have compromised safety.
On this occasion it states that the two flat silver discs were reported to be stationary, or very slow moving, about 100 feet below the flightpath.
The pilots who saw the objects described them as "toy like" and the risk to the planes was assessed as low.
However, the report did concede that the sighting could not be explained.
Mr Pope added: "There is a disturbing side to this encounter, understandably played down in the official report.
"The UFOs – whatever they were – came dangerously close to hitting the aircraft.
"Whatever people believe about UFOs, we were 100 feet from catastrophe."