A huge fireball was seen streaking across the sky in north-eastern US and Canada in the early hours of 17 May. Footage from a police dashcam showed the meteor burning up above Portland, while the American Meteor Society said it received almost 700 reports from eyewitnesses.

"The AMS has received nearly 700 reports so far about a fireball event over Northeastern US on May 17th 2016 around 12:50am EDT (4:50 UT)," a statement said. "The fireball was seen primarily from Maine but witnesses from Vermont, New Hampshire, New Jersey, Massachusetts, New York, Rhode Island, Pennsylvania, Connecticut, Ontario (Canada) and Québec (Canada) also reported the event."

Footage and still images released by the Portland Police Department shows the meteor above the city sky. In the video, one of the offices is recorded saying "oh my God".

portland meteor fireball
The meteor seen above Portland Portland Police Department

In an interview with WMUR Channel 9, New Hampshire resident Syd Thompson said: "I saw everything started to get bright, and all of a sudden we saw this big ball come right in front of us. Then the whole sky got brighter and brighter and brighter. As it went away, it got all these colours ... It was absolutely gorgeous."

Meteors are fragments from space that enter Earth's atmosphere. As they do so, they burn up, appearing as a streak of light. Earth is constantly being showered with dust and sand-sized meteors and most are too small to be seen.

The Maine Mineral and Gem Museum is now offering a $20,000 (£17,000) reward for meteorites from the fireball weighing above 1kg. "Based on hundreds of eyewitness accounts collated and analysed by the American Meteor Society, it's clear that the meteoroid entered Earth's atmosphere over Maine and its terminal explosion occurred about 30km west of Rangeley, Maine in Franklin County.

"As fireball observations go, this one was huge—and a similarly huge reward awaits a lucky resident ... Based on the number of bursts in the sky, a number of meteorites may have made it to Earth."