My husband & I were in Rockefeller Center sitting on a bench facing south. I was looking up at the sky above the building directly across the street from the ice rink. The night sky was black above this building. Then out of nowhere, to the left of the building, way up above us I saw what looked like a star. It was a little round light. At first I thought it was a helicopter. The object flew over the building way above it and then started to fly erratically, darting from side to side almost as if were jumping back and forth. Then it disappeared. There was nothing in the airspace. There is consistent lighting in the area and there was continued darkness above. This was the only thing in the sky. I have seen a lot of planes and helicopters before but this was nothing like that. There is No way anyone could fly an object and all of a sudden start jumping around side to side in an erratic flight pattern. It could not have been a falling or shooting star because this did not have a clear straight pattern. I would also like to add that this object appeared out of nowhere and disappeared in a span before the building and after. It did not come from behind a building.