The source of a long trail of lights seen by many Tasmanians speeding across the sky yesterday afternoon remained unknown last night.

Tasmania Police switchboards were inundated with phone calls from across the state about 1.30pm -- all from people concerned about the lights which appeared to be heading downwards as they headed south.

Police told the Sunday Tasmanian the sightings had triggered fears that a plane or a meteor was about to crash to the ground.

Some callers had thought distress flares were being let off.

Launceston Planetarium curator Martin George said last night the descriptions he had heard sounded as if it had been a meteor burning up after entering the Earth's atmosphere but this could not be confirmed.

Witness Debbie Gibson was at Seymour Point, just north of Bicheno on Tasmania's East Coast, when the scorching light caught her eye.

"We were on the beach and I looked up above the water and saw this glistening thing in the sky," she said.

"It was really bright, and had a long thin tail which trailed behind it.

"But it was the colours which were really noticeable.

"It was yellow and blue and kind of silvery at the front of the light -- it looked like it was burning.

"It was going really fast and only probably took about eight seconds to stretch over the point and out of sight.

"I have never seen anything like it."

Elsewhere around the state, people thought they were watching a disaster unfold.

Acting Sergeant Tom Burley of the police radio dispatch service said initial callers were seriously worried.

"Some people rang in saying they thought a plane had crashed," Acting Sgt Burley said.

"Others around Hobart said they thought flares had been let off over the Derwent."

Acting Sgt Burley said police received more than 20 calls from concerned residents.

"We had calls from the Bass Highway near Latrobe in the North-West, from Bicheno on the East Coast and from south of Huonville in the South," he said.

"And there were a lot of calls from around Hobart.

"Everyone described a bright burning light which crossed the sky in a southerly direction."

Mr George said he had not seen the light, but had made several phone calls when he was alerted to the episode.

"From what I have learned from the various reports, it seems the most likely explanation is that it was a natural object entering the Earth's atmosphere," Mr George said.

"For an object to be this bright, it would typically need to have the mass of a few kilograms.

"I understand it was seen for up to about nine seconds which is unusually long for a meteor, but not unknown.

"From what I have been able to determine, no man-made objects were expected to re-enter the atmosphere so it does not appear to have been space junk."

Mr George said meteors that were easily visible during the day were extremely rare.

"To see something as clearly as people did yesterday, a person would have to watch the sky for several hours a day, for several years," he said.

Mr George said if the light had been a meteor it was likely to have either burnt up before it reached the ground or landed somewhere in the ocean.