Ever heard of the Lubbock Lights? My parents were sitting on a porch in Plainview Texas and saw those fly over. There was no sound just the steady straight flight of the round objects. Later she saw pictures of them that were taken from Lubbock about 50 miles south of Plainview. They were in the exact formation as when she'd seen them earlier.
Just found this sight, go look. http://www.subversiveelement.com/LubbockLights.html