Defending the Earth against Asteroid and Comet Attack – how are we doing?

By popular request Dr Benny Peiser from Liverpool John Moores University returned to the SciBAr after a very successful session on Global Warming to discuss the issue of an asteroid or even a comet crashing to Earth to cause the sort of devastation which drove the dinosaurs extinct. How likely is this? What would be the effects on human civilisation? Is there anything we can do about it? What would we need to do and when? Dr Peiser has an asteroid named after himself and also one named after his daughter and is well placed to give us the real run down on what could be a disaster. What should we be doing and are we doing it? If you had come to the SciBAr you would know.