A stargazer's guide to the universe

A stargazer's guide to the universe

University of Western Ontario researchers revolutionize meteor observation
August 13, 2008
Catch a falling star and put it in your pocket…well, not yet. For now, the Meteor Physics Group at the University of Western Ontario (UWO) has the ambitious goal of recording every mote of dust, sand grain, or chunk of rock that enters the atmosphere above Southwestern Ontario to map out the meteor environment. And they’re doing so with cutting-edge technologies that can collect unprecedented data—data that could reveal how planets originated.
 

When meteors enter the Earth’s atmosphere, they move so fast they burn up, leaving only a brief trail of electrons. The UWO meteor group’s Canadian Meteor Orbit Radar (CMOR) observes a few thousand meteor trails each day. While the radar doesn’t actually see meteors, it does identify their trails, providing scientists with detailed information on the meteor’s orbit, potential landing sites, and composition.

Because meteors come from comets and asteroids, they act as perfectly preserved records of the solar system since it was formed. Therefore, meteor data provides an unparalleled glimpse into the make-up of the ancient universe. “Comets and asteroids are the least altered bodies in the solar system,” confirms Peter Brown, a leading meteor scientist at UWO. “But it is difficult to go out and study them directly. Spacecraft are expensive. But, you can study meteoroids as a proxy for these parent bodies.”

Until recently, there was no way to capture the detail of a meteor before it burned out. But now, thanks to the UWO group’s ingenious idea of combining a high-resolution video camera, mirror and telescope, they are able to collect unmatched imaging of meteors. The camera records 100 frames per second of the sky, as seen off the mirror. When the camera detects a meteor, it moves the mirror so the telescope can get a close-up within four frames—faster than the blink of an eye.

“With a typical telescope, you are lucky to get maybe one event per night, whereas we will get 20 to 30 events an hour,” says Margaret Campbell-Brown, a meteor scientist with the UWO group. “With that amount of information and all of it [recorded] automatically, it’s going to mean a revolution in how we observe meteors.”

“Basically, we can do a sample return mission without spending any money on spacecraft to go there,” explains Campbell-Brown.

Meteor dust samples could also tell us a great deal about our planet’s development and perhaps even the origins of life on Earth.

“A lot of people have speculated that the smallest planetary dust particles could have been the dominant source for organic molecules to the Earth,” says Brown. These particles from billions of years ago can now be found in meteors. “If you want to study the origins of life, you want to get a handle on what meteor bombardment was doing to the earth,” he says.

Understanding the meteor environment also helps with more immediate concerns such as spacecraft safety. Through the data they collect, UWO develops models of meteor density and sizes in space that NASA then uses in its spacecraft design. “Meteoroids pose, to a manned vehicle, the greatest risk in orbit of any other environmental factor,” says Bill Cooke, lead scientist at NASA’s Meteoroid Environment Office in Huntsville, Alabama. “Western provides the only resource in North America with the capability we need.”

Although the UWO meteor group has noted a decrease in the quantity of meteors hitting Earth compared to eons ago, the Earth is still regularly hit by a large number during a meteor shower. The UWO’s meteor environment models have helped make shower predictions many times more reliable. In fact, the peaks of meteor showers have been nailed down from hours to within minutes, letting stargazers worldwide sit back and enjoy the shows.