NEW YORK - The holly, jolly, best time of the year got a light-filled launch on Wednesday when the towering Christmas tree at Rockefeller Center was officially turned on.The 79-foot (24-meter) Norway spruce, covered with more than 50,000 lights in a rainbow of colors and bearing a crystal-covered, 900-pound (400-kilogram) star, was lit in a midtown Manhattan ceremony again open to the public, in contrast with last year's virus-impacted event.The lighting was televised on NBC.