According to some reports the number of near Earth objects is now of the order of 2000 per year and several of those have been undetected until only a few days

According to some reports the number of near Earth objects is now of the order of 2000 per year and several of those have been undetected until only a few days prior to nearest approach. I'd factor in this eventual inevitability as well. One day some large object will be on course that will spell the end for us. Time to gear up in preparation given that our present defensive resources are pitiful.