Researchers examine the site where a ball of fire was seen hitting the ground. (CBC)

A meteorite expert says a strange ball of fire that landed in a P.E.I. farmer's field last Saturday was not from a meteor.

Robert Hawkes, a professor of physics and specialist in meteors at Mount Allison University in New Brunswick, was asked by P.E.I.'s fire marshal to review evidence gathered on Louis Campbell's field in Grahams Road.

Campbell said he was sitting on his front yard when he saw a ball of fire land in his field. He said it was about the size of a football.

On Tuesday, after examining the site northeast of Summerside, Hawkes said he was disappointed but not surprised to discover that a meteorite was not the cause of the fire.

"We had a slight hope, I gave the estimate as one chance in a thousand there was a meteorite," he said.

Fire officials recovered a handful of what looked like ash.

Too flaky

Hawkes said a meteorite looks like a rock, with metallic bits in it. The professor — who has published more than 50 scientific papers on meteors and has contributed to two books on the subject — said the substance found by firefighters was too flaky to be a meteorite.

"Most meteorites would not break up into totally just flakes of stuff, which is what that looked like," he said.

"Most meteorites are stony objects that don't look that different from stones here, but they would have a black fusing crust and there's no indication of that."

Hawkes said the last meteorite recovered in Atlantic Canada was found in 1959.

Dave Blacquiere, P.E.I.'s fire marshal, told CBC News he's not sure what fell from the sky in Grahams Road. He said it may have been a flare or a firecracker, but no one in the area saw anything that would match that type of activity.

"If it were going to lead somewhere, to us having to come up with a definitive answer, we're just going to have to accept the fact that we had an incident here and we can't explain it away," he said.

Blacquiere said the investigation is over and the origin of the ball of fire will remain a mystery.