The Sudbury Star is the City of Greater Sudbury’s daily newspaper.
A city known for its rock and snow may well have been formed, nearly two billion years ago, by a giant ball of rock and snow.
New research by Laurentian PhD candidate Joe Petrus suggests the Sudbury basin was the work of a comet, which blasted through the atmosphere at a speed of about 50 km/second and struck with such force that debris rained down as far away as Thunder Bay and Minnesota.
Scientists have understood since the 1960s that the area owes its shape and geology to the impact of a celestial object, but exactly what type of object — asteroid or comet — has remained an open question.
It was a puzzle that Petrus, who earlier studied physics, couldn’t resist probing. “‘Why hasn’t somebody done this?’ ” he recalls thinking. “It seemed a glaring question, especially since Sudbury is one of the most important impact craters on Earth.”
The doctoral student also felt the timing was right. While there had been some earlier speculation about a comet being the cause of Sudbury’s crater, more sophisticated technology was now available to test the theory.
Petrus’s study, undertaken with the support of PhD supervisor Balz Kamber, formerly affiliated with Laurentian University, and geologist Doreen Ames relied largely on chemical analysis of rocks in the impact zone.