You can snap images of only the sky and more often than not, catch 'something' up there. Upon close-up views etc. modern aircraft is ruled out, dust is ruled out, birds are ruled out, dust on lense is ruled out. (for my images)

Take several images- then people can't say it's dust (unless it is), they can't retort "dumbass, its a bird" etc...

Several pics, same area one after the other. This is the only method that will keep people like Duncans trap mouth shut. That guy is a gov shill, this is obvious. This isn't about him though- it's about those who think they can discredit something because they don't understand it, or never had a personal experience with it.