The lights on the 23-meter-high Christmas tree at New York's Rockefeller Center were turned on Wednesday continuing a tradition begun in 1931 that marks the beginning of the holiday season.
In a surprise feature, NASA's Expedition 6 astronauts at the international space station, led the countdown of the tree-lighting ceremony at Rockefeller Center.
"Okay guys, from 240 miles [386 kilometers] up in space, here we go: P -10, 9, 8, 7, 6, 5, 4, 3, 2 1, light the tree!"
But it was New York City Mayor Michael Bloomberg, former astronaut Buzz Aldrin, Santa Claus and others who actually flipped the switch, illuminating more than 30,000 lights on the giant Christmas tree.
The annual tree-lighting ceremony, now in its 70th year, started when workers lit up a small Christams tree atop the Rockefeller Center, then under construction.
An estimated 65,000 people gathered at the New York City landmark in freezing weather to watch the evergreen glow.
The Norway spruce, hauled in from the nearby State of New Jersey, is more than 13 meters wide and weighs about seven tons.
The two-hour, nationally televised event featured well-known American entertainers performing Christmas favorites.
A shivering singer Barry Manilow, who performed from his new Chrismas album, said he used to visit the tree as a child growing up in New York. "To me, it represents New York City at its most beautiful," he said.
The festive event also featured popular singers Sheryl Crow, Kelly Rowland and Carly Simon. Several Broadway casts and the Radio City Music Hall Rockettes also performed.
It was very different from one year ago, when the event was held less than three months after the September 11 terrorist attacks.
Then, in a city still suffering the aftermath of the disaster, New York City Mayor Rudolph Giuliani was joined by First Lady Laura Bush to flip the switch in a show of solidarity with New Yorkers.
This year, the Christmas tree in Rockefeller Center will be on display until January 7.