Ontario researchers want to hear from anyone who saw a basketball-sized fireball in the sky east of Toronto Monday night or has found fragments of the fallen meteorites.

"We're hopeful that somebody in the area heard something, sees some weird rocks on their back lawn in the next day," Kimberly Tait, associate curator of mineralogy for the Royal Ontario Museum in Toronto, said in an interview Wednesday.

"Maybe they have a broken window in their backyard and don’t know why. That's what we want to hear."

The meteor, described as a "slow-moving fireball, estimated to be no bigger than a basketball," was recorded at 6:04 p.m. ET Monday by six cameras that are part of the University of Western Ontario's Southern Ontario Meteor Network, the university said in a news release.

Meteorites, meteors and asteroids Meteorites are fragments of rock or metal that have landed on Earth after falling from space. They are usually pieces from a comet or asteroid orbiting the Sun.

are fragments of rock or metal that have landed on Earth after falling from space. They are usually pieces from a comet or asteroid orbiting the Sun. Meteors are fireballs or "shooting stars" visible in the sky when a piece of space rock enters the Earth's atmosphere. The friction heats the rock until it glows brightly.

are fireballs or "shooting stars" visible in the sky when a piece of space rock enters the Earth's atmosphere. The friction heats the rock until it glows brightly. Asteroids are bodies made of rock or metal that range in size from boulder-sized to nearly the size of a small moon or planet. Most of the asteroids in our solar system form part of the Asteroid Belt orbiting the sun between Mars and Jupiter.

Researchers think it likely dropped meteorites ranging in size from one gram to hundreds of grams east of Selwyn, Ont., north of Peterborough, near the end of Upper Stony Lake, about 115 kilometres northeast of Toronto. They may have a total mass of up to a few kilograms.

"The meteorites themselves will be black rocks. They will be a little bit heavy, they'll be magnetic, and of course, since they've just recently landed, they might have kicked up some dirt," said Peter Brown, director of the University of Western Ontario's Centre for Planetary and Space Exploration.

They may also have landed on top of snow.

Brown said anyone who finds what they believe to be a meteorite fragment should take it to the Royal Ontario Museum in Toronto or email a photograph to the museum.

While the meteor fell during the Geminid meteor shower, researchers said it wasn't related to that event.

Finding the meteorites could be challenging because the area where they landed is covered in forests and lakes, Tait said.

"Really, to cover the ground walking is very difficult in that area," she said

Spotting meteorites is difficult even under the best conditions, she added: "These are black rocks that can hide very well amongst other rocks."

Tait said she and her colleagues plan to do a small search at some point, but in the meantime, they are hopeful that their public appeal will yield more immediate results.

Brown said a similar appeal in 2009 helped researchers locate a meteorite that hit an SUV in Grimsby, Ont.

Because researchers tracked the meteor's trajectory with their cameras, they can figure out where in our solar system it comes from. They say it is rare and valuable to be able to combine that information with an actual meteorite sample.

"Finding a meteorite from a fireball captured by video is equivalent to a planetary sample return mission," said Brown in a statement Wednesday.

P.O.V. What would you do if you found a meteorite? Take our survey.

"Only about a dozen previous meteorite falls have had their orbits measured by cameras … so each new recovered meteorite is adding to our understanding of the formation and evolution of our own solar system."

The video footage showed that the meteor first entered the atmosphere at an angle of 25 degrees from the horizontal, moving at 14 kilometres per second. It first became visible over Lake Erie, then moved toward the north-northeast and remained visible until it reached an altitude of 31 kilometres, when it was just south of Selwyn.