well i dont think that there are techniques to see it, you just see if it's fake or you don't, nowdays we can produce very realistic fake images with tools like photoshop, and 3d programs, so it's more how good the artist/faker is with his programs. sometimes if you look close you can see things like that the proportions look weird (so that it looks like the ufo is really small, or the houses (if you see any) look fake, or that the edges are blurry, what means that the object isn't cut from his background well, but these are just things which you notice without anyone telling you, and if you don't see any strange things, the image is good faked, or the image isn't fake (wich won't be the case with your ufo image... ;) i hope that helped grd stef