“I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet Earth.”- Stephen Hawking
From 1948 through 1969, the United States Air Force was charged with investigating UFO reports. The responsibility lay with a task force called Project Blue Book. Evolved from two previous air force studies, Projects Sign and Grudge. By the time Project Blue Book ended, it had collected 12,618 UFO reports, and concluded that most of them were misidentifications of natural phenomena (clouds, stars, etc.) or conventional aircraft. …But a small percentage of UFO reports were classified as unexplained, even after stringent analysis.