It was the day New York stood still.
The bright object seemed to divide into several smaller objects and then slowly move together again.
Adding to the mystery, a former Air Force officer predicted four months ago on a UFO website that an alien craft would visit major cities on October 13th, saying, "The aliens will reveal themselves in a massive uniform display over our principle cities and I predict this will happen on October 13th, 2010."
Stanley Fulham is the author of a book on UFO visitations, and don't worry. He says they come in peace.
George Stephanopoulos could hardly believe it on Good Morning America.
"That retired Air Force officer who predicted aliens would come all across the world said they would come, not stop or talk to anybody; they just want to signal that they're around," joked Stephanopoulos.
The New York Post said the UFO over the upscale Chelsea neighborhood "Had the City Agape," and The Daily News asked, "What the Heck Was That?"
Not even the Federal Aviation Administration can explain the phenomenon. A spokesman says the object is not a weather balloon, calling it "nothing we can account for."