I am an agnostic on this subject. But this agnosticism comes from a combination of strong lifelong interest in astronomy and the possibility of extraterrestrial life, up to and including the possibility of galactic empires (à la Isaac Asimov and others).

Right from the start, with private pilot Kenneth Arnold's sighting on June 24, 1947 of nine disc-shaped objects flying in formation near Mt. Rainier in Washington State (he described them as "flying saucers," and the news media picked up the phrase), I have read up on the subject extensively, starting with Donald Keyhoe's book, Flying Saucers are Real, in which he poses some very interesting theories.

Arnold's sighting was not really the first, of course. All through history there have been sightings of unidentified objects in the sky, from Biblical times (Ezekiel's "wheels within wheels"), to the sighting of a silvery disc-shaped object over Yorkshire, England in 1290, to the mysterious "foo fighters" that U. S. Air Force, RAF, and Luftwaffe pilots spotted over Germany toward the end of World War II, and many more such reports.

Over the years I have talked with people who said they had observed such phenomena first hand, such as a man who had worked at the White Sands proving grounds shortly after the end of WW II, testing first captured German V-2 rockets and later the American-made Vikings. He said that every time they had a test launch, almost predictably, silvery disc-like objects would appear and seemed to be observing and pacing the test rockets as they were launched. They registered on the radar, and at times planes were sent up in an attempt to intercept them, or at least observe the objects, but they proved too elusive for our fastest interceptor jets. Maury was a solid realist with both feet on the ground, and he was not given to BS-ing anyone. He said, "We have no idea of what they were or where they came from. It's a cinch the Russians didn't have anything like that, and we sure as hell didn't!"

I also talked a bit with an older man (a Boeing engineer, in fact) who said he'd had an encounter while driving on a country road, but he became so agitated when he mentioned it that he broke off by saying, "I'm sorry! I just can't talk about it!" And he, too, was not the sort that was given to flights of fancy or to BS-ing.

I have also talked to some real flakes. And read stuff written by flakes.

I would be very surprised if we were to learn beyond a shadow of a doubt that we are the only intelligent (!??), technological species in the universe. Or even in the galaxy. I am acquainted with a person who works in the Astrobiology department at the University of Washington, and have read a lot on the subject. It's amazing the amount and variety of life on this planet that not only lives, but thrives, in extreme conditions right here. Example: the great concentrations of life surrounding volcanic vents ("black smokers") on the oceans' floors. These life forms draw their energy, not from sunlight, but from heat. The temperature of the water they live in is over 700 degrees, and that would kill most "life as we know it." What prevents the water from simply vaporizing at that temperature is the pressure at those depths. And the area is teeming with a whole variety of life-forms.

Undoubtedly there are many planets orbiting stars similar to our own sun, and G-type main-sequence stars are not that rare. In fact, the vast majority of stars are "main-sequence," hence the name. That includes some very nearby stars. Alpha Centauri, a triple-star system, contains two stars similar to the sun, one of which could easily host a planetary system, and it's only 4.3 light-years from us. It is possible, indeed likely, that there are a plethora of earthlike planets that would be just as hospitable to life as Earth itself is. All one need do is spend a bit of time perusing the Drake equation to get an idea. The formula comes up with a very conservative set of figures, but which predicts the probability of there being some 10,000 planets with intelligent and possibly technological societies within this galaxy.

Studying the Drake equation is very enlightening—and downright exciting!

Is it possible that Earth has been—is being—visited by intelligent, technological extraterrestrials? Most assuredly! Has Earth been, or is it being visited?

There are claims, and a plethora of conspiracy theories, all intertwined like a snake's nest, but no one has yet been able to provide credible evidence that this has happened or is happening. I think it's quite likely—for reasons that Donald Keyhoe gave in his magazine articles and subsequent book (Flying Saucers are Real, 1950)—that we have been visited from time to time and during the past several decades, we are being scrutinized rather closely.

But—

This is pure speculation, with no actual evidence or proof!

An Unidentified Flying Object is exactly that:   an Unidentified Flying Object. Many Unidentified Flying Objects have subsequently been identified, and the mystery disappears. They turn out to be quite mundane, merely initially unidentified, or misidentified. Some Unidentified Flying Objects have not been identified, and they remain a mystery. Kenneth Arnold's "flying saucers," or the WW II "foo fighters."

But to change the "U" in UFO to an "A"—A for Alien—and then make the leap that a UFO is, ipso facto, an AFO or "Alien Flying Object" flatters the case and commits the fallacy of Begging the Question.

Begging the Question does not mean "insisting that a question be asked" as many members of the news media have been misusing it lately, but refers to a commonly found logical fallacy:   attempting to prove that something is true by using the assumption that it is true as one of one's premises. It is a sort of logical "Trojan horse." In the context of this discussion, of course, "alien" is assumed to mean "extraterrestrial." Nor can one hedge one's bets by claiming that "alien" is merely a synonym for "unidentified." It isn't.

Neither Aristotle, nor any first-year logic student would find that argument acceptable.

So, on the subject of alien visitations to earth, I think it might very well be true. But I don't know.

And neither do you.

And if you claim that you do know for certain that we have been visited, don't expect to be believed unless you have evidence.

I am open to being convinced. So convince me.

But remember:    extraordinary claims require extraordinary proof.

Don Firth