Purported UFO taped flying over South Korea

Are we really alone in the universe? A video shot from a plane flying over Seoul, South Korea, shows what appears to be a UFO flying over the city. The silver, saucer-shaped object is seen at first holding steady with the plane's pace, before rapidly picking up speed and darting out of the frame.The video's uploader speculates the object might be a military drone, or, it could be, as one user puts it, a cap from Super Mario brothers.