THE HOME-MADE UFO
Ingredients: some flimsy plastic laundry bags of the sort you get from dry cleaners when they return pants, small candles, strips of thin balsa about 1" x 12", large tacks or small nails, scotch tape, scissors, aluminum foil, matches, a paranoid military air base with fighter aircraft, one vehicle, and some intoxicated college students.
Scotch tape the balsa strips into a cross holding the bottom of the laundry bag open. Make certain they are secure to the bag. Stick the tack or nail through the center bottom of the cross pointing up. Stick the candle firmly to the sharp end of the tack/nail.
Cut some long thin aluminum foil strips (1/2" x 6" is fine) and scotch tape them to the balsa strips.
Fluff the bag open, light the candle and see if the sucker will fly as a hot air balloon. Do this where you can't be observed, where there is no wind, and far away from possible air traffic. It would help if you have a BB gun to bring it down in case it gets away from you. The test is to make certain you didn't weigh it down too much with aluminum foil strips. You want this thing to climb fast.
Make another one. Find a spot near the air base which is as close in as possible, with a line of sight to the control tower, but safe from base security or other possible trouble, and where you can hop in the car and get away fast.
Wait until night - about 2 am. Go there and launch the UFO.
The aluminum foil strips act as radar reflectors and make the thing appear as a big blip on the control tower's radar screens. They won't be able to pick it up visually and will think it is a much larger object much farther away.
The slight movements of the balloon as it sways in the breeze will appear on radar as though the UFO, perceived to be far away, is darting back and forth at incredible accelerations.
With any luck they'll launch some fighters to investigate.
Sorry, but this explanation is more unbelievable than a actual UFO. Oh, and we did the plastic bag thing as a kid, and no one would think it was traveling at a high rate of speed to the point of leaving fighter jets in the dust, as this witness observed.