Last night I saw a UFO.
It was about 10:30 pm and after watching some tennis on TV I went outside to look at the stars. The half-moon was up in the northwest, and the usual stars were visible. But to the west there was a very bright light in the sky.
I knew the bright light wasn't a star. Sirius was up above and it's the brightest star in the sky; this light was brighter than that. My first thought was that it might be a planet - perhaps Jupiter. But I didn't know what it was. It was a UFO.
I have an 8 inch telescope, and it was quite a good night for watching the stars anyway (warm and clear at this time). So, I set up the scope and turned it to the bright light in the sky.
After changing eyepieces a couple of times, I looked through the scope with the highest power eyepiece I have. The light in the sky looked like a kind of squashed ellipse. It also seemed to have coloured bands, and it shimmered as I looked at it. It was kind of yellow on the top half, and below that its colour seemed to graduate through a reddish colour, with a dark blue below.
There's no way this was a star, because it had a definite size in the scope, quite unlike the sharp pointlike appearance that stars usually have. I could only observe it for about 10 minutes before it dropped below the level of the roof of the house next door.
Could I solve the mystery of this UFO?
There are a couple of clues. First, the object appeared to be "setting" in the sky at the same rate as the nearby stars. That suggested to me that it was an astronomical object rather than a flying craft of some kind in the sky. But if I didn't know better I could easily have reported it as "hovering" over the nearby houses. If I'd had to guess at its size, the only thing I would have had to compare it to would have been those nearby rooftops, chimneys and so on. To the naked eye, it looked big and bright, so if I had assumed it was close I could easily have reported its size as about the size of a Boeing 747 at a distance of a few blocks away from where I was watching it. It made no sound like a "regular" aircraft at that distance. It shimmered in the air, both to the naked eye and in the telescope.
That shimmering is another clue. This was a warm night. With daylight saving, the sun had set only about an hour and a half before I saw the UFO. Warm air rising off the earth can cause shimmering of astronomical objects - astronomers call this "seeing". It is responsible for the "twinkling" of stars. And here I was looking westwards towards the horizon (over the rooftops), with the object quite low in the sky. That meant I was observing it through a large thickness of atmosphere.
What of the object's appearance? A squashed ellipse? The atmosphere can cause some refraction of light, making circular objects near the horizon appear elliptical. But that effect alone was not enough to account for the squashed appearance of this object.
There was a half moon. We see a half moon when the directions of the Sun and moon, as seen from Earth, are at a 90 degree angle to one another. So, what about this object? Suppose it was a planet. Can planets show phases like the moon? Can we possibly see a half-Venus, for example? The answer is "yes".
Did the appearance of the object indicate possible reflection of sunlight from a planet? Through the scope, the top half of the object was bright, and the bottom half was dark. The sun had just set in the west no long before, so the sun was "below" me. But that would mean that if the Sun was lighting the UFO then the bottom half of the UFO should be bright and the top half dark. But that wasn't what I saw through the scope; I saw the opposite.
Colour? The predominant colour of the UFO was yellow-orange. Other colours seen could be due to imperfect telescope lenses/mirrors, atmospheric refraction and the like.
So, bright yellow-orangish object in the sky? I knew it wasn't Jupiter or Saturn, because with my telescope I can make out bands on Jupiter and the rings of Saturn, and I could see no such thing here. So, how about Mars?
The object's colour was not exactly what I expected for Mars, but it was approximately right. But if this was Mars, why was the top half (the half on the "opposite" side to the Sun) illuminated? Answer: my telescope gives an inverted view of the sky (it's a Newtonian reflector). With the naked eye, I couldn't tell which side the UFO was illuminated - the thing just looked like an elliptical light - but the scope gave a better, and accurate, view.
I tentatively identified my UFO as the planet Mars.
I spent another hour and half at the telescope, looking at the "Jewel Box" in the Southern Cross, the Orion Nebula and its Trapezium of new stars, at the Pleiades (the "seven sisters" of Greek mythology), at the beautiful global cluster in the Tucana constellation near the south celestial pole. I saw directly that Alpha Centauri - the brightest "pointer" to the Southern Cross - is not a single star at all, but two distinguishable stars (actually there are three, but I can't see Proxima with my scope). Then I went to bed.
This morning, I checked the positions of the planets with a "night sky" app. Right now, Venus, Mars and Uranus are all close together in the night sky. But Uranus is invisible even through my scope, and Venus was below the rooftops by the time I went outside last night.
And Mars? Mars was exactly where I saw the UFO. My UFO was Mars.
I wonder what I might have thought if I had been a policeman back in 1966 Portage County, watching the same object "hovering" above the rooftops. A policeman with no particular interest in astronomy, who had heard and read many recent reports of alien spaceships in the sky. A policeman with no ready access to astronomy texts or phone apps.