Ralf might have missed it, but like it says in the article, there are volunteers around the world watching out for this thing, and they only needed to track it periodically - and communicate among themselves as a group about their findings - in order to keep tabs on it.
Things get exponentially easier when you've got more hands and eyes on the problem - not to say its not a difficult task, but lets remember - a group of people put it up there (that was pretty hard) - and now a group of people are tracking it.
Things get exponentially easier when you've got more hands and eyes on the problem - not to say its not a difficult task, but lets remember - a group of people put it up there (that was pretty hard) - and now a group of people are tracking it.