Unidentified Flying Objects exist; there is no way to even cast doubt on their existence. If anyone sees a flying object and cannot identify it, then it is, by definition a UFO. Of course, the purported evidence that any of these flying objects are actually extra-terrestrial in nature is categorically and unequivocally fraudulent, mistaken, misunderstood, hallucinatory or delusional.
The only evidence for the existence of extra-terrestrial visiting the earth is, at best circumstantial. In every case, it is arguable and not conclusive. There are some eerie pieces of evidence, but they never can amount to much. That's why this topic is in the spiritual category. Belief in extra-terrestrials is akin, in nature, to the faith one must have to believe in ghosts, angels, devils, demons, djinn or other supernatural beings. So, let's examine the best of this evidence.
Close Encounters of the First Kind. These are events where on observer in some way sights a flying object. Photographs of such sightings are wonderful pieces of evidence. Unfortunately, albeit expectedly, not a single photograph or piece of video footage, remains conclusive. Outside of the vast number of apparent and obvious frauds, the images of natural phenomena or internal camera products, and the images that are too fuzzy to be of any value, there are a very few that are truly unexplainable. That does not mean that they are evidence of extra-terrestrials, just that they have not yet been explained.
My father-in-law, a retired veteran United Airlines pilot, once when he had been loosened up with a number of cocktails, once professed to have seen a ufo, something perhaps extra-terrestrial. He, of course, being a generally sober, intelligent and rational man, would never tell anyone he had seen such a thing.
You see, this is really the only kind of evidence that could persuade someone to believe in extra-terrestrials, the same way a personal encounter with the Lord Jesus Christ could convince someone to believe in God. But this is never a rational choice, not a scientific and logical decision. The belief in God is an internal, introspective and highly personal act of faith. And so is the belief in extra-terrestrials.
Close Encounters of the Second Kind. The second type of evidence from ufos is physical effects from the ufo. This can include burned patches on the ground, radiation, crop circles, human paralysis and the like. Well, almost every single example of these phenomena, even though they may or may not be associated with strange lights in the sky, are explainable using meteorological or physical science. the kind of paralysis described by people visited by efos seems remarkably like a form temporal lability, or even sleep paralysis. Some of these are cases of superimposed "recovered memory," from dubious psychological leading.
This is nearly always the most fraudulent form of evidence for extra-terrestrials. Books are written showing pictures and accounts of the physical evidence without presenting any of the realistic physical and rational possibilities.
Close Encounters of the Third Kind require the observation of an actual alien. There has never been a single photograph of an alien, either on the autopsy table or not, that has stood the test of critical analysis. Whereas there a re genuine cases of photographs that are unexplainable, these third kind encounters are universally the work of fraud and hype.
Close Encounters of the Fourth Kind involve abduction. Now, why advanced extra-terrestrials who do not want their existence known are so anxious to anally probe humans and mutilate cattle, no one has yet answered to my satisfaction. Perhaps these are inter-galactic frat-boys on a joy ride. The most famous abduction case is the case of the Hills. Although their supposed star map, which they claimed to have seen, has been shown to be the fabrication of astronomically illiterate humans, there are still people who will point to their interviews as proof.
This is the most difficult evidence to discuss rationally. It seems cruel to accuse people of making up these stories. What would they have to gain? Any fame or popularity would surely be outweighed by the ridicule and scorn that would be heaped upon them. And many of these abductees do not even want any attention. Some are emotionally scarred by their "experiences."
But that does not preclude their truth. Many of these individuals have delusions, some even created by the unscrupulous and unethical use of psychological processes known as "recovering memory." These recovered memories are often planted in a suggestible state so that the patient actually perceives them as real memories. Talk about you Manchurian Candidate! And some are cases of sleep paralysis, or temporal lobe lability. But doesn't it make more sense to examine and uncover the possible motives behind these spurious personal accounts rather than to search for the aliens?
There are a few cases of Close Encounters of the Fifth Kind, in which individuals make contact with extra-terrestrials and engage in a two way dialog. In every case, these are universally bat guano. The nonsense spouted by these supposed extra-terrestrial aliens is more childish than what children usually come up with. Some have claimed that radiation is an instrument of diabolic origin, even though light itself is radiation. Some have claimed that the aliens came from "the constellation of Ganymede," even though Ganymede is a moon of Jupiter, and constellations are a grouping of stars in the night sky and are separated by gazillions of parsecs. Just listen to this stuff, and it makes the rot that the Heaven's Gate cult believe seem sensible.
There is plenty of supposed evidence, and lots of true believers who will claim to be stifled in their ability to tell the truth, or to get the news out, or that mysterious government forces are out to hide the truth. This is nonsense. Think about it. The President of the United States, the most powerful man in the world, cannot get oral sex in the Oval Office from an intern without the whole world knowing about it. The best minds of the FBI and CIA botched the assassination of Castro not once but multiple times. These guys can't keep a secret, and they certainly wouldn't be able to keep this one. Even if they had extra-terrestrial help.