Posted 10 January 2013 - 11:49 PM
Notice how the oval shape's long axis is dead level with the horizontal axis of the picture? That's a pretty good hint that somebody used Photoshop's ellipse-select tool to create the shape. Feather the ellipse and the changes inside it could be done using, say, 'levels', or 'brightness/contrast' or something else pretty easy. Rinse, repeat, you've got a UFO movie.
So: Photoshop.