One thing's for sure when it comes to a mysterious object over the skies of Prince Edward Island: No one knows what it was -- not even the UFO experts.

Chris Rutkowski, research co-ordinator for Ufology Research in Manitoba, said the object trailing a dark, spiraling plume behind it in January over the island is not a UFO.

But Rutkowski is at a loss to identify exactly what it was an islander captured on video and that left the entire country guessing as to its origin.

"We're puzzled," Rutkowski said in an interview late Monday. "But we're fairly certain it was terrestrial phenomena."

The non-profit UFO organization began investigating the strange sighting after islander Marie Ford sent them video footage she'd shot of the dark plume.

Ford said Tuesday the sighting has left her baffled. "I guess we'll never know."

At the time of the incident, Ford's husband Tony said the object was "definitively unidentified," but ruled out "Martians or anything like that."

Instead, he speculated that perhaps it might have been a jet plane dumping fuel. Other suggestions have included everything from space junk to tornadoes.

Ufology researchers enhanced the film using digital image processing and examined close-ups of screen captures, but were still unable to determine what the object might have been.

Rutkowski said he's certain it's not a meteorite or a "chunk of comet" entering the atmosphere, because the object was in the air for too long-- nearly 30 minutes.

Nor does he believe it's a satellite or rocket booster. According to Rutkowski, typically space objects travel eastward, but this object was heading west.

"At this point, we simply have to chalk it up to the unexplained," the researcher said. "Because it has all the earmarks of something resembling an aircraft or a fireball of some sort that originated within the atmosphere, I'm fairly certain there is an earth-bound explanation."

According to the group's annual report, 736 UFOs were spotted in Canada in 2006 and 96 fireballs were reported. British Columbia had the highest number of sightings with 209, followed by 188 in Ontario and 98 in Saskatchewan. Prince Edward Island has the lowest number of sightings, reporting only one.