Astronomer Frank Hitchens examines the threat to Earth from comets and asteroids. How likely is it that we'll see an impact on the magnitude of the one which led to the extinction of the dinosaurs? Could even a small impact threaten our civilization, and is it possible to avert disaster? Saturday, September 22, Isabel Turner Branch, 2 p.m. A free event for adults and teens. Seating is limited, so please register in advance to avoid disappointment. Register online at events.kfpl.ca or by phone at (613) 549-8888, starting at 9 a.m. on Saturday, September 8.