I don’t believe in aliens because of the distance and the evolutionary cycle and so many other reasons but I was flying over water in a de havilland turbo prop on the way to Manilla about four years ago and out of the window I saw a sphere with octagonal panels about twice the size of a football travelling about 30 mph slower than us. I watched it in plain sight for about 30 seconds as we passed it.
I put it down to some kind of weather balloon but it was doing 300+ mph with no sign of propulsion. There stuff we just don’t know. -Simon