May I ask how you know that extraterrestrials exist and have the ability to break the laws of flight and physics as you understood them? Or to phrase it differently, how is your conclusion more sound than that of the Aztecs when they concluded the Spaniards were gods, or that of the old Norsemen when they figured thunder and lightning bolts had to be the work of a god with a "thunder hammer"?
The problem with identifying a UFO as an extraterrestrial vehicle is that it presupposes that such a vehicle exists, and acts in a way that correlates with what you describe. If we had an extraterrestrial craft of any kind, we'd be able to compare sightings with what we knew of this craft's look and capabilities, the same way I can see an F-16 fighter in the sky and identify it as such because we possess knowledge of what an F-16 looks like. Identifying a UFO as a vehicle controlled by an extraterrestrial intelligence, however, is circular reasoning. You might as well say it's a god or goddess out on a nightly patrol.