No credible evidence of any physical extraterrestrial presence here on Earth.
To equate the UFO phenomenon unequivocally with physical extraterrestrial visitation borders on pseudoscience and is no different from a religious belief. However, religion is religion and science is science. There is nothing wrong in having a religious belief, since it is an intrinsic part of human nature. I, for one, am a strong believer in the existence of God, His creation and His divine plan for our life.
Dr. Jacques Vallee suggested that "there is a spiritual component...the UFO phenomenon is controlled by a nonhuman sort of consciousness." But he also proposed the possiblity that the UFO phenomenon could even be "material photoplasmic projections of the collective unconscious of the human family". But the bottom line is we still do not know.
While suggesting that the government has been just as perplexed by this phenomenon as a segment of the public, I agree totally with Col. John Alexander that there has never been any intentional "cover-up" of this phenomenon:https://www.facebook.com/notes/norio-hayakawa/no-credible-evidence-of-any-physical-extraterrestrial-presence-here-on-earth/10152330581751352