The pilot immediately called Shannon Air Traffic Control (ATC) to see whether there were any military exercises taking place in the airspace.
A spokesman for the Irish Aviation Authority (IAA) said: "Following reports from a small number of aircraft on Friday 9th November of unusual air activity the IAA has filed a report".
"It was moving so fast", said the pilot of a British Airways flight from Montreal to London.
Shannon ATC queried: "Alongside you?".
She said it came along the left-hand side of the plane before veering rapidly north.
Whatever it may have been, pilots stated that the bright light was going at an "astronomical" speed of at least Mach 2 (2,500 km/h), which is twice as fast as a commercial jetliner! "We didn't think it was a likely collision course, just wondering what it could be".
He described it as a "meteor or another object making some kind of re-entry".
Senator jokes about sitting front row at 'public hanging'
Former Democratic Rep. and Agriculture Secretary Mike Espy at a rally for his Senate campaign in Jackson, Miss., on November 5. The state's population has the highest percentage of African-Americans of any state, 37 percent according to the last census.
He said there were "multiple objects following the same sort of trajectory" and that they were very bright.
Safe to say we're very spooked.
Air control reported nothing was scheduled for that evening.
It's believed three different pilots have been recorded saying they saw something that they can't explain.
The pilot on VS76, who also witnessed two bright lights, offered a possible explanation. The fact that Speedbird 94 provided a "close-up" account of the incident while Virgin 76 conveyed a "wide-angle" account that made this encounter even more compelling.
The Virgin flight confirmed the objects were heading at his "11 o'clock position" and that "two bright lights over to the right" could also be seen climbing away at high speed.
He said that one of the pilots had actually suggested it was a fireball.