Almost all of these ufo are test aircraft that the public doesn't know about. The stealth fighter was responsible for most of the sightings in the late 60s early 70s. Scientist who have worked at lockheed said that they have been working on some science fiction shit since the 70s. USA has several aircraft that would be described as ufo. One is called the flux liner and niggas leaked the physics behind it. They have at least 5 anti gravity aircraft and some are disc shaped. The pilot who saw the object just doesn't know what we have. It could have been from another planet, but most likely was from us.