The path of a meteorite filmed at intervals (Photo: National Research Council of Canada)

Some people dream about exploring space. Others, like the scientists who study meteorites, are thrilled to find fragments of celestial bodies here on Earth.

Meteorites are rocks that fall to Earth from space and range in size from a grain of sand up to 50 tons or more. Upon hitting the Earth, the larger ones leave impact craters. Most meteorites found on Earth have come from our solar system's asteroid belt between Mars and Jupiter, while some have been blasted off the Moon or Mars by another impact.

Most meteorites are fragments of asteroids

Aerial view of New Quebec crater, formed by the landing of a meteorite (Photo: Planetary and Space Science Centre, University of New Brunswick)

Clues to the origin of the solar system Meteorites reveal a lot about the origin of the solar system to the planetary scientist. They tell of the composition of planets, asteroids, and the Sun, the nuclear processes within other stars, and the chemical evolution of planets. Scientists who study asteroids and their orbits try to discern the possibility of a collision with Earth and the preventative measures.

"Meteorites are four-and-a-half billion years old-older than the Earth," says Dr. Alan Hildebrand, a planetary scientist with the University of Calgary's Department of Geology and Geophysics, where he holds a Canada Research Chair in Planetary Science. "These samples of the solar system are recovered for free or a tiny fraction of the cost of a space mission."

Coordinating meteorite finds

Hildebrand is also a member of the Canadian Space Agency's Meteorite and Impacts Advisory Committee (MIAC), a volunteer group of scientists who coordinate meteorite reporting and research in Canada. The group, helps identify suspected meteorites, investigates meteors, studies impact craters from large meteorites, and runs the Canadian Fireball Reporting Centre. MIAC members were involved in one of the largest and most scientifically significant meteorite finds in Canadian history, discovered in the ice of Tagish Lake, Alberta, following a spectacular fireball sighting in January 2000. The meteorite turned out to be rich in rare particles that were formed before our own solar system

This meteorite was found by Mr. Gerald Goldenbeld in 1992 in a field south of Fort MacLeod in Alberta (Photo: University of Calgary)

A fragment of the ice-encased Tagish Lake meteorite-the largest find in Canada.  (Photo: University of Calgary)

If a meteorite falls in the woods … "Since the glaciers left 10,000 years ago, about a million meteorites have fallen on Canada, but only 66 have been found to date," says Hildebrand. "The number of meteorite finds is low because the country is so sparsely populated. When one falls in the forest in Northern Ontario, it's likely that no one has spotted it."

But there have been close encounters with meteorites in populated places. In 1997, a meteorite fell so close to a group of golfers in Southern Ontario that one of them heard it fall and found it! "Statistically, this might happen once every 10 years in Canada," says Hildebrand. Alberta is the leading province for meteorite recoveries with 16, followed by Saskatchewan and Ontario with 14 each.

The Innisfree meteorite landed near an Alberta town of the same name on February 5, 1977. A camera network, operated by Canada's former Meteorite Observation Recovery Program, detected its fall. (Photo: Alan Hildebrand)

Alan Zalaski (left) found Canada's most recent meteorite, which was identified by Tom Weedmark (right) during the 2005 Prairie Meteorite Search.  (Photo: Alan Hildebrand)

Is there one in a field near you? One way to find meteorites is by using a camera system to track fireballs when the sky is clear, and then try to predict where they fall. Several MIAC members have all-sky cameras for this purpose.

To date, the most successful effort to find meteorites in Canada has been the Prairie Meteorite Search, also funded by the Canadian Space Agency. Since 2000, this public outreach campaign has identified eight new meteorites. The most recent one was found near Lake Eliza, Alberta, by Alan Zalaski while exploring his property. When he took it to a clinic run by the Prairie Meteorite Search during the summer of 2005, the space rock was positively identified.

If you stumble upon a meteorite you might not recognize what it is, but you will see that it's different from most rocks. It will usually be denser than an ordinary rock and rust-coloured, often with a dark crust. Because it contains iron, it is magnetic.

But you don't have to be a scientist to hunt for them. "Dozens of meteorites fall on Canada every year. They're all around us, so anyone with a bit of curiosity and persistence could find one," says Hildebrand.