A ball of light that blinked into South Florida’s inky predawn sky Wednesday before bursting into pieces with dazzling long-lived tails was a hunk of cosmic scrap metal, one of 25,000 objects the Air Force tracks in space. The flaming debris, part of a Chinese CZ3 rocket body, was forecast to reenter the atmosphere Wednesday morning but no one predicted the delight and awe it would spark in those who saw it lazily fall toward Earth just after 2 a.m. At least two people called the Palm Beach County Sheriff’s Office, one who said there were UFOs over the skies...