If you look at an F-117 at just the right angle, it looks exactly like a flying saucer.
In 1983, I was stationed at the MCAS area at Yuma and our entire battalion was treated to an air show over the desert. Suddenly, a squadron of 6 F117 fighters flew over and I was certain they were alien! All of us were speechless, and we were all told that they did not exist and not to ever mention them to family or friends and we never did. But they were finally announced to the public during Desert Storm. They were developed before the B2 bomber. Our platoon commander said they could become invisible, but then later clarified it "to radar". At the time I believed they could REALLY go invisible.