The stunning footage films the sky above the London airport before the flash of light whizzes past.
It came just seconds before a large jet landing at the airport comes into view, and it has not yet been determined what the mystery sighting is.
Precisely what the object was is unclear, neither is it known how close to Earth – and the plane – it might have been.
The footage was captured by plane-spotting site Airlive, which suggested the celestial body was a shooting star.
Tweeting the clip from its official account, the site said: “Look at that amazing shooting star our cam just caught in the sky of Heathrow Airport!”
Clemens Rumpf, a visiting specialist in space debris at the University of Southampton, told the Mail Online he believed the spectacle was of a large meteor.
He said: “These events occur harmlessly multiple times a year but can be spectacular when caught on camera.
“There was probably no immediate danger for any passenger aircraft as these objects tend to burn up, as seen in the footage, at altitudes of 20 to 45 miles (30 to 70 km), well above the flight level of planes.”
The British Journal Editors and Wire Services