"It was colored white, green and gold, and lights seemed to blow off it like it was a sparkler," said one observer, Andre Grønmo. "It looked like it was a comet, and it was around four- to five times larger than a plane, and it flew much faster."

Several police districts logged reports from members of the public who observed "something" flying at high speed.

"What they're talking about here is some sort of flying object, and we can't explain what it was," Oddgeir Slettli, operations leader for the Midtre Hølogaland Police District, told dagbladet.no.

Observations were reported from Finnsnes to Trondheim. The main search and rescue station in northern Norway (Hovedredningssentralen Nord-Norge) reported that calls also came from crews on board ships off the northern coast, according to Dagbladet.

"It was colored white, green and gold, and lights seemed to blow off it like it was a sparkler," said one observer, Andre Grønmo. "It looked like it was a comet, and it was around four- to five times larger than a plane, and it flew much faster."

Slettli said others described a "green, lighted ball with a tail" that flew low. He said neither the Defense Department's radar station or its rocket facility at Andøya, nor the tower at Evenes airport, which serves Harstad and Narvik, had picked up the object.Slettli said calls came from people in Narvik, Vesterålen and Lofoten among other places, just before midnight on Monday.

A flurry of reports also came over the Coast Guard radio, and from an SAS flight and a Hurtigruten (Coastal Voyage) passenger ship.

Knut Jørge Røed Ødegaard, one of Norway's most well-known astronomers, said he thinks the UFO was actually another meteorite, a large rock containing a lot of chemical elements. There have been confirmed reports of at least two meteorites hitting Norway since June.

"When they enter the earth's atmosphere and meet the air, they warm up and can light up in a second," he told dagbladet.no.

This one's contents, the astronomer said, could explain why it seemed to change color as it flew through the night sky, which only recently has started getting dark again after the summer's midnight sun.