As Phil Plait, of the Bad Astronomy Blog, has pointed
out on a number of occasions, amateur astronomers usually do not report UFOs (Unidentified Flying Objects). Why might
that be? I think that I am safe in saying that the meaning of the acronym UFO has changed over the years. It used to
mean: I just saw something in the sky, and I have no idea as to what it might be.
Now UFO seems to mean: I
just saw an alien space ship (or Flying Saucer if you prefer) fly by.
Do amateur astronomers ever see an object
in the sky that they are initially unable to identify?
On occasion, yes we do; but with a little persistence, usually we are able to figure out what we are looking at. Once
we have figured out what we are looking at, two things have happened. Firstly, the object is no longer unidentified,
and secondly there is no Flying Saucer in sight. So by both meanings of UFO, there is nothing to report. But even
though the end of the journey is something of a null result, perhaps the journey itself is worth reporting. Perhaps
amateur astronomers should report an occasional interesting UFO. Perhaps I should report a UFO. So here you go Phil;
Ask and Ye shall receive.
Back in the mid 1970s, when I was working for the University of Alberta, Department of Physics, in the Astrophysics Group, the astronomer in the group acquired a grant to upgrade the observatory, located west of the city, with a new larger telescope. Part of the project involved moving the old telescope into the city and installing it on the roof of the physics building, in a new sliding roof observatory. This new observatory was used for astronomy course labs and on Friday evenings, we held public observing sessions.
On one Friday evening, the sky was clear and the seeing was very good. After the public had left, the student volunteers, who had been helping out with the public observing session, took this opportunity to pursue their own interests at the telescope. Myself and one of the fourth year students were standing outside on the roof just looking up at the sky, when a flight of four UFOs passed directly over head. The UFOs appeared quite suddenly, about 45 degrees above the southern horizon, passed directly over head and disappeared, again quite suddenly, about 45 degrees above the northern horizon.
The UFOs were round and white, and were flying in a diamond formation; one in front, two on either side and one bringing up the rear. They swept out about 90 degrees of sky in under three seconds. Both of us had been facing south and we were now facing north, when the following conversation ensued.
Student: Ahhh, did you see that?
Me: Yeah, I saw that all right.
Okaaay. What was it?
I don’t know, but let’s keep out eyes open. Maybe they will come back.
So we both turned back to the south again and started scanning the sky; only this time we were not looking at the stars, we were looking for UFOs.
Before I carry on with this report, let me stop and ask if there are any questions. Suppose that this event ended right here (it doesn’t). What questions would you have for me? Do not read ahead just yet. Stop and think of what questions you would like to ask. Now imagine that you are watching this on Larry King Live. What units of measure do Larry’s guests usually use when describing UFO observations? What units of measure ought they be using?
Above I asked you to think of questions that you would like to ask someone who has just witnessed a UFO event; so now let me anticipate the questions that you might have:
Let me answer these questions in reverse order:
Were those the sorts of answers that you were expecting? Probably not if you had the image of a typical Larry King Live UFO episode in your mind. When reporting UFOs, most people make the mistake of trying to assign absolute sizes, speeds, and distances to an object that they are unable to identify. Let’s think about the geometry of the situation for a minute and consider the implications for size, distance and speed.
If the objects had been fairly close to us, then they would not have been very large and would have been moving with modest speed. However if the objects had been at some middle distance, then they would have been rather large and moving at a high speed. Of course, if the objects were at an extreme distance from us then they would have been absolutely huge and moving with incredible speed.
So back at the roof top observatory, the two of us were intently scanning the sky, looking for UFOs. They did return;
four round white UFOs approaching us from the south again. On their first pass, we were taken completely by surprise
as the UFOs came and left before we were able to get our wits about us. As they made their second pass, we were
staring intently at the objects trying to figure out exactly what we were looking at. As the objects passed overhead,
the drama of the incident evaporated in an instant. Both of us made a positive identification and uttered the same
word at the same time: Pigeons!
In an instant, four UFOs had been replaced by four pigeons flying overhead. So what was going on in our minds to turn
pigeons into UFOs? This is a classic case of Seeing What You Are Believing.
I tend to think of information from
our senses as passing through filters —or being assembled onto templates by our brains — as we are trying to make
sense of what is happening around us.
This means that the same sensory information can be interpreted quite differently by our brains on different occasions, depending on what filters or templates may be in operation at any given moment. In the case of our pigeons, light from the street lamps below was being reflected back to us much better from their round white bellies than from the rest of the pigeon, making the bellies stand out much more against the black sky. Essentially, as soon as we saw the four round white objects, a UFO filter popped up in our brains. It is absolutely amazing how effectively the UFO filter filtered out the rest of the pigeons.
On the first pass, there was no hint at all of a pigeon. By the time that the pigeons made their second pass, each of
us had managed to set aside the UFO filter and replace it with more of a OK, what are we really looking at?
filter. As the pigeons approached, those round white bellies were so mesmerizing; it took a lot of concentration to
see past the bellies to the rest of the pigeons.
From time to time, pigeons would fly over the roof top observatory, and each time I noticed them, I initially saw round white objects. As with an optical illusion to which I knew the real answer, I initially saw the illusion. Each time I had to concentrate to see past the illusion, to a pigeon.
There is an interesting epilogue to this event. Some time later, during a public viewing session, I was once again
standing out on the roof looking up at the sky. Standing near by, was a young fellow, about 14 years old, when a lone
pigeon flew overhead. The young fellow turned to me and said WOW! Did you see that? A UFO just flew across the Big
Dipper!
Yes
I replied, That happens occasionally up here, and it turns out that they are not UFOs, but
pigeons.
I then launched into an explanation of round bellies preferentially reflecting light and filters in
brains preferentially selecting data, etc, etc.
Even though this event predates the movie ‘Men In Black’ by about 2 decades, I must have been doing a pretty good impersonation of the Will Smith character trying to convince someone that they had not seen what they had just seen, because this young fellow was not having anything that I was telling him.
He knew what he saw (well perceived actually) and he certainly did not see any pigeon. It was written all over his
face, the absolute disbelief at what he was hearing. As the expression goes, I could almost see the wheels turning in
his head, as he was trying to rationalize what I was saying with what he had seen (perceived). The expression on his
face gradually changed from disbelief, through comprehension, to Eureka! as he was trying to figure out what was
happening. He then took a step backwards, pointed a finger at me, and shouted YOU’R PART OF THE
CONSPIRACY!
I was completely taken aback by this and could not come up with a better response than NO, NO, honestly, that was
a pigeon!
And so he turned and walked away, apparently secure in the knowledge of two things. Firstly, there are
Flying Saucers visiting us, and secondly, there is a grand conspiracy afoot to keep this knowledge from the general
public. And all of this because he certainly did not perceive any pigeon.