Scientists say a golf ball-sized rock that smashed through the windshield of an SUV is a meteorite, possibly from a spectacular fireball that streaked across the sky above Hamilton three weeks ago.

University of Western Ontario researchers confirmed the rock was a meteorite. It will be unveiled today at a media conference.

The fireball was captured on video Sept. 25 by a network of cameras administered by Western that regularly watch the skies at night. One of the cameras is located at McMaster University.

For the past two weeks, a search team headed by Phil McCausland, a postdoctoral fellow at Western's Centre for Planetary Science and Exploration, has been scouring the Grimsby area after working out mathematical models that suggest the fireball crashed there.

McCausland believes there are other meteorites on the ground that have yet to be found because the meteor weighed as much as a tonne when it hit Earth's atmosphere.

He returned to Grimsby yesterday with a search team of a few people looking around the residential area where the meteorite was discovered by a Grimsby resident.

"It was a very unusual rock, so the finder just held onto it," McCausland said. "They began to think it was a meteorite after the media coverage happened."

He would not be specific about where the rock was located, only that it was "just barely" within the 12-square-kilometre area south of the town of Grimsby that searchers were focusing on.

Tests are being done to try to find out more about the 50-gram object.

The discovery, he said, has buoyed enthusiasm that other pieces will be found and it will turn out to be a major find for the astronomy community.

Meteorites are relatively common, but it is highly unusual to find one from a meteor videotaped coming through the atmosphere.

"You don't stop when you find one piece. You keep going," said McCausland. "Finding one is confirmation that something came down here and there are probably many others."

They are looking intensively in the area of the first find because "meteorites don't care where they land. They could hit a house, a roof. They can end up anywhere."

mmcneil@thespec.com

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