Turkish Airlines TK2525 green-light object over Silivri, near Istanbul Atatürk Airport

Thursday, May 19, 2016. Turkish Airlines flight TK2525 was on its way from Bodrum to Istanbul, a Boeing 737 with the registration TC-JHD. In the cockpit sat Captain Sadık Kakıcı and First Officer Gökhan Keleş. Around 23:30 local time, they were over Silivri, a district of Istanbul Province on the Sea of Marmara coast. At about 17,000 feet, they were starting their approach to Atatürk Airport.

Then something crossed the sky above them. An unidentified object, giving off green light, passed 2,000 or 3,000 feet higher than the aircraft, moving across their path ahead of them. Then it disappeared.

Both pilots saw it. They called Atatürk air traffic control. "From 2 or 3 thousand feet above us, an unidentified object, emitting green light, crossed in front of us. It suddenly disappeared. We're guessing it's probably a UFO." No shape was reported. No size. The flight went on, and the aircraft landed safely at 00:37.

The State Airports Authority, DHMİ, checked its records. Its answer was brief. There was no image on the radars like the one the pilots described. The Doğan news agency carried the story on May 20. Within days, Habertürk printed the pilots' full names and opened a newspaper series on UFO reports with their account. No statement from Turkish Airlines has been found, and no ATC audio has ever been published.

Then the story travelled. EgyptAir MS804, an A320 flying from Paris to Cairo, had crashed into the Mediterranean early on May 19 with 66 people on board. From around May 23, outlets including the Daily Mail, HuffPost UK and Daily Pakistan claimed the Turkish crew saw their UFO "just an hour before the doomed Egyptair jet crashed", "some 500 miles away".

The dates say otherwise. The Turkish sighting came on the evening of May 19, hours after MS804 vanished. Inquisitr's headline got the order right. Later reporting on the cockpit voice recorder showed the MS804 crew trying to fight a fire. The foreign copies garbled other details too. Some placed Silivri near Ankara. One French account turned 2,000 to 3,000 feet into "0.7 mètre".

No official explanation was ever given. Gary Leff of View from the Wing called the UFO crash theory "bizarre", a case of confirmation bias. His scorn was aimed at the MS804 speculation, not at the pilots. Nobody has questioned their honesty.

One conventional candidate is a bright green fireball. It would fit the colour, the fast crossing, the sudden end and the empty radar screens. Meteors burning high in the atmosphere can also seem far closer than they are. But no catalogued fireball for that night over Turkey has been found. Another aircraft's green navigation light seems less likely. Traffic that close, near a busy approach, should have shown on radar.

The next afternoon, on Belceğiz Beach at Ölüdeniz in Fethiye, chemical engineer Celal Toprakçı was photographing his daughter Zeynep as she paraglided down from Babadağ. He said four frames caught a green object moving from east to west. "The object then vanished on the horizon." Karar's headline called it the UFO the pilots saw over Silivri. It was a separate daylight sighting, roughly 350 kilometres away.

TK2525 joined a long line of Turkish pilot reports, from Hami Yüksel in 1967 to THY captain İbrahim Bilir in 2010. A green light that crossed and vanished. Two professional witnesses. No answer.