"What particularly troubles Peiser is that scientists only first spotted 2001 YB5 in early December. What if it had been heading on a collision course?


They're getting better, then! Often these small rocks are only identified after closest approach!


RB
PS: Only just found this board after TMFSelena's post over on Notable Boards. I guess I've haven't spent as much time in astronomy recently, but keep up with a few websites & New Scientist.
(in the past I was on the Committee of the Cambridge University Astro. Soc, and hence have used the oldest telescope in regular use - the Northumberland)