Such fine tuned tereports are something the ship didn't have proper equipment for. The people going after Osir are likely more the "black bag" folks and the operations are not quiet "official" and so they have limited forces. The U.N.S. was a bit more official so it had more resources (And a better reason than pure greed). The .4c rock that came in could not be targeted accurately because of the nano coating on it. People only knew it was there because of it's gravity which likely isn't enough to get an accurate targeting solution with and No Ships were in range (It was well inside the defense zone when it was detected.) Also the UNS forces are there at the behest of Petey.