10-tonne asteroid lit up Prairie skies: Univ. of Calgary
Published Tuesday, November 25, 2008 8:09PM EST
A fireball that streamed across the skies over Alberta and Saskatchewan last week was a 10-tonne asteroid, according to a researcher at the University of Calgary.
Alan Hildebrand, co-ordinator of the university's Canadian Fireball Reporting Centre, said the rock would have been the size of a desk as it entered the atmosphere, before breaking up into meteorites.
He has mapped out a region in western Saskatchewan where he believes the surviving fragments can be found.
"We are now starting to reasonably constrain where the meteorites will have fallen," Hildebrand said in a press release issued by the university Tuesday.
"Many witnesses reported seeing a cluster of red fragments continuing downwards in the sky after the fireball exploded. These represent the rocks slowing down that will eventually fall to the ground as meteorites."
The buzz surrounding the landing site has some nearby residents curious about where the space rocks will be found. Debbie Waddell, who lives in Edgerton, Alta., said she thinks locals will beat the meteorite hunters to find the ultimate prize.
"If anybody ever finds anything it'll be a deer hunter or someone that finds it," she told CTV News.
It's believed the asteroid entered the atmosphere at about 14 kilometres per second -- a relatively slow speed, which means meteorites larger than 50 grams could have survived the trip to solid ground.
Most asteroids enter the atmosphere at around 20 km/s.
On Nov. 20, witnesses in Alberta and Saskatchewan reported seeing a bright light streak past them overhead. Some sent videos of the sighting to CTV's MyNews.
"The public response to this fireball has been the largest that we have ever had in Canada," said Hildebrand.
He urged witnesses who recorded the event to save a copy and contact him through the university.
Kevin Proctor said he has already told Hildebrand about his experience seeing the fireball.
"I watched it go to the southwest and before I lost sight of it over the horizon it burned out," he told CTV News. "For probably about a minute afterwards you could hear a low rumbling sound like thunder."
With a report from CTV Edmonton's Sonia Sunger