Goodnight Blue Book
The UFO world deepens with a discussion on the various investigations the United States Government has embarked on over the past 70-ish years.
UFO's are probably at the top of my list of unknown things. There are continual twists and turns in the field that make it very fascinating. There are the basic sightings of strange lights, green flashes, saucer sightings, up to the contactee movement, alien abduction phenomena, and, of course, the government conspiracies.
The fact that there are numerous investigations should be enough proof that UFO's absolutely exist. It doesn't mean there are extraterrestrials visiting earth. It doesn't mean that there are secret moon bases or space forces, but it does mean that there is something out there. Among the Chinese lanterns, and misidentified space stations, planes, air force black programs, and drones is something that the Government has continually decided it doesn't know enough about that gets them back on the UFO train time and time again.