Independent groups that monitor satellite traffic say they could tell that the Iridium satellite and the Russian satellite were going to pass near each other, but because of other satellite traffic and space junk floating in the area, could not actually predict collision, according to published reports.

Some of the debris was created when Chine blew up one of its own defunct weather satellites nearby with a missile in 2007. The Iridium satellite was orbiting 485 miles above the arctic, which is high enough that the atmosphere doesn't slow them down and shorten their usable life but low enough to provide high-quality signals.