Footage has emerged from a horrified passenger, known as only Mr Chang, who was on board the flight travelling through a thunderstorm, on its way from Atlanta to Las Vegas, in the US.
According to reports, the commuter spotted the anomaly after waking up due to the weather conditions.
The video appears to show an orange light glowing in the middle of the thunderstorm.
It then cuts off before we can get a better view, apparently after Mr Chang’s phone died.
The clip was shared on popular YouTube conspiracy page secureteam10 on Thursday and has sinced racked up more than 550,000 hits.
And viewers were left speculating what it could be.
One comment read: “Aliens are landing on the Earth and causing these anomalies.”
But others believed it could be more sinister still.
Another viewer claimed: “That glow in the sky is HAARP in action.”