Footage of this incredible bubble-like burst of light in the night sky was captured by cameras at an astronomical observatory in Hawaii.
Sky watchers have been flooding internet forums with speculation about the burst, filmed by a webcam mounted on the Canada-France-Hawaii Telescope on Mauna Kea.
Captured in time-lapse footage, the glowing sphere takes several minutes to expand until it virtually fills the frame – then it vanishes as mysteriously as it appeared.
Theories as the cause of the mysterious luminous sphere have ranged from the opening of an inter-dimensional portal to the future to a battle between two alien starships.
But the most likely explanation is that is shows a U.S. Minuteman III inter-continental ballistic missile (ICBM), ejecting fuel as it enters the upper reaches of the Earth’s atmosphere.
The time-lapse footage shows the night horizon filled with stars, when suddenly an ethereal arc pops into view.