While I was thinking about strange lights in the sky awhile back, it naturally came to mind that the U.S. military, after decades of denying it, has finally let it be known that their guys have logged some inexplicable airborne events. They call these events “unidentified aerial phenomena” — or UAP — trying to shuck the acronym that has become one of the most spectacularly ambiguous words in the English language: UFO.

This led to thinking about a couple of personal experiences I have by and large kept to myself for, um, decades. One in particular.

In this image from video taken in 2015 and labeled Gimbal, an unexplained object is seen at the center as it soars high along the clouds, traveling against the wind. “There’s a whole fleet of them,” one naval aviator tells another, though only one indistinct object is shown. “It’s rotating.” The U.S. government has been taking a hard look at unidentified flying objects, under orders from Congress, and a report summarizing what officials know is due out this month. Image courtesy of Department of Defense via AP

Then a couple weeks ago came a report from credible news outlets about a former U.S. intelligence official who says he has indirect but documentable knowledge that aircraft of nonhuman origin, or at least pieces of them, have been recovered and studied. The U.S. government and some others, he said, have worked on back-engineering technology from the craft. He does not know about any aliens.

The guy’s name is David Grusch. He reportedly is an Air Force veteran of combat in Afghanistan and later was the National Reconnaissance Office’s representative to the government’s Unidentified Aerial Phenomena Task Force. So he’s had firsthand access to the information. Other military officials have vouched for his integrity.

It’s really hard to know what to make of this. If the government has been keeping secrets about crashed aircraft of nonhuman origin for the last eight decades, then how could David Grusch possibly be the first whistleblower on the secrets? If you have read much about UFOs, you know that is a rabbit hole you do not want to go down, because you’ll almost instantly be unable to separate fact from fiction from hoax. On the other hand, you might also know that serious, objective researchers and journalists have investigated thousands and thousands of UFO reports and repeatedly concluded basically two things: 1) Something strange is going on, and, 2) It is not known what it is.

You’re kind of left to your own disposition, to your ability to sort fact from fantasy, and in some cases, to your own experience. Not to put too fine a point on it, but it was a personal experience of mine that I thought of during my strange-lights kick. I have told this to very few people before letting it fly, so to speak, here.

I am not making this up.

One afternoon in about 1972, I was walking across the Million Dollar Bridge from Portland to South Portland. My eye was caught by flashing lights to my right. I looked over to see, as clear as day, a cone-shaped aircraft plugging slowly along toward the bridge, maybe 75 feet above the Fore River. It was about the size of a Volkswagen bug. The tip of the cone pointed up, and flashing lights were running around the lower rim.

I stopped to watch it. How did it stay aloft? I had a hundred or so hours piloting small airplanes as a teenager, and knew about lift. I thought there must be a large propeller in the base. But I could not see any propeller, and I had never heard of a helicopter-like rotor installed inside an aircraft with no wings or rudder visible. Whether that could even work seemed doubtful.

But there it was. Flying. As solid and real as everything else in the scene.

I can’t actually remember seeing it cross the bridge, but I do have an image of it dawdling away downriver toward Portland Harbor.

I walked home and excitedly tried to tell my brother and father what I had seen. I wanted to call the Portland airport and ask them to help me identify it. My father, who being a pilot was a frequent visitor to the airport and knew people there, was pretty skeptical of the whole story and discouraged me from making any such call.

Because whatever I saw was so solidly real, it did not occur to me right then that I was seeing anything but some kind of experimental aircraft which, somehow, flew with a rotor in its base. What it would be doing in Portland, Maine, was a baffling question.

I put the incident away in memory, figuring that eventually I would learn about such a vehicle. But as far as I can tell, there is no conventional aerodynamic way to get lift to fly the structure I saw chugging along over the Fore River.

It was a long time before my skeptical scientific mind relented and started referring to it, in my personal memory banks, as a “UFO,” whatever that might mean. In the literature, there are documented accounts of people — sometimes many people at the same time — similarly seeing strange unidentified aircraft in broad daylight, in cities, with no FAA explanation for what they saw. I’ve seen a couple of drawings from such sightings of cone-shaped crafts that resemble what I saw that afternoon.

It’s hard to know what to make of this. Something strange is going on, and no one seems to know exactly what it is. Not even the guys with access to the secrets.

Dana Wilde lives in Troy. You can contact him at dwilde.naturalist@gmail.com. His book “Summer to Fall” is available from North Country Press. Backyard Naturalist appears the second and fourth Thursdays each month.