An Auckland-bound jetliner came close to being hit by blazing pieces of what is thought to have been a Russian satellite hurtling into New Zealand airspace.
However, Nasa said today it was convinced the flaming objects were not from a satellite and space experts said it could have been a meteor.
Aviation authorities are investigating how flaming wreckage thundered close to the Lan Chile Airlines Airbus A340 flying from Santiago, Chile, on Tuesday night.
The debris was so close to the aircraft that the pilot could hear the roar it made as it broke the sound barrier.
The alarmed Airbus pilot notified Auckland Oceanic Centre after seeing flaming space junk shooting across the sky about five nautical miles in front of and behind his plane at about 10pm.
At the aircraft's cruising speed of 880km/h it was within about 40 seconds of a potential catastrophe.
According to a planespotter who was tuning in to a high-frequency radio broadcast at the time, the pilot "reported that the rumbling noise from the space debris could be heard over the noise of the aircraft".
He described how he saw a piece of debris lighting up as it re-entered [the earth's atmosphere]. He was a very worried pilot as you would imagine.
"Auckland is talking to [an] Aerolineas Argentinas [pilot] who is travelling [in the] opposite direction at 10 degrees further south asking if they wish to turn back to Auckland." They have elected to carry on at the moment.
"It is not something you come across every day and I am sure the Lan Chile crew will have a tale to tell," the planespotter said.
Nicholas Johnson, orbital debris chief scientist for Nasa's Johnson Space Center said he checked with the Russians and that debris -- an empty Progress resupply ship that had been at the International Space Station -- fired its re-entry rockets a half day after the airliner reported the near-miss.
"Unless someone has their times wrong, there appears to be no correlation," Johnson told the Associated Press news agency.
He said he knew of no other re-entering space junk spotted by global trackers at about that time.
Airways NZ spokesman Ken Mitchell said today a meteor had not been ruled out.
He said: "The information we have been providing to the media has been based on the information we have had to hand and the eyewitness report of the pilot."
"An official investigation will determine exactly what the case is."
The Pacific Ocean is regularly used as a graveyard for disused satellites and other space debris. The general location and time of their return to earth is relayed to air traffic controllers, who then tell the airlines.
But on this occasion, if it was a satellite, the estimate of its fall to earth was out by 12 hours. If the timing was wrong, the co-ordinates of where the satellite was supposed to enter the earth's atmosphere would also have turned out to be incorrect.
The Sydney Morning Herald reported that the pilot told air traffic controllers of flaming space junk plunging across the sky near his plane about 10pm on Tuesday.
But Airways New Zealand, which manages all air traffic operating within New Zealand's 37 million square kilometer airspace, was told by Russian authorities to expect a satellite to come out of orbit between 10.30am and 12pm yesterday, which it duly passed on to the airlines.
"That time appears to be incorrect," said Mr Mitchell last night.
Mr Mitchell said air traffic controllers at the Auckland Oceanic Centre immediately notified all other aircraft in the vicinity.
"There was one other aircraft not in the immediate vicinity. But that aircraft elected to continue. Once the debris had actually fallen, there was probably no other risk."
The other aircraft is believed to have been an Aerolineas Argentinas flight travelling in the opposite direction.
Airways New Zealand is preparing an official incident report to be handed to the Civil Aviation Authority, which will also investigate.
Mr Mitchell said it was an unusual event. "It's not uncommon for space debris to fall to earth - those times and general locations are made available to us."
"It is uncommon to have a plane in the middle of it, and it is uncommon to have the timing of the debris incorrect."
He could not confirm the name of the satellite although the Sydney Morning Herald reported it was likely to have been the Russian Progress 23P cargo freighter. He added: "Five nautical miles is uncomfortably close."
No one has ever been killed by rogue man-made space junk, although in 1997 an Oklahoma woman was grazed in the shoulder by space junk.