Teachers occasionally ask me what my teaching philosophy is as I participate in the public programs at Perkins Observatory.

Frankly, I don’t know enough about astronomy to break new ground. Thus, I try to start with what the kids think they already know.

Many of them can recite the distance from the sun to the Earth (93 million miles or 150 million kilometers to the hipper students). Such large numbers are, of course, meaningless to them. Quite frankly, they are meaningless to me.

So, I reduce the sun to the size of a volleyball. On that scale, Earth is the size of a pinhead. We pace out the distance together (about 37 paces for a short guy like me). At that scale, the sun, a million-mile-wide hydrogen bomb, is about the size of their little fingernails held at arm’s length. That’s what 93 million miles really means.

They know that the sun moves across the sky because Earth spins around once every 24 hours. They learned the words in school, but they don’t really know it.

I tell them about an experience I had when I was 12 years old. I watched in binoculars as the moon set behind some trees. As the moon slowly disappeared, my imagination leapt. For an instant, I imagined the moon standing stock-still, and I felt the Earth spinning in the opposite direction.

I knew at that moment that the Earth rotated, that we live on a spinning ball hurtling through space. I knew it not just in my head but also in my heart, where it counts. And I say to those kids, “I am standing here talking to you today because I went out that night and looked at the moon.”

It is out of such experiences that a lifelong love of knowing things is born. I wish for all of them such a simple, yet profound moment.

At that moment, I knew in an incoherent way that my life had changed. I knew that I had found that one true thing that gave — and still gives — my life meaning and purpose and joy.

But I found something much more profound even than that. “I have to show everybody this beautiful thing,” I thought to myself. I had found my purpose, but in a way that in very real yet very hard to define, I had also found my humanity.

My experience of the suburban sky was limited by the glow of nearby city streetlights. Increasingly, they cast their ugly yellow stain across the sky and shield us from its beauty.

I had to go to the College of Wooster to experience the mind-altering splendor of the real sky. COW, as its denizens ironically call it, is placed in “Ohio’s foremost agricultural district,” or so the signs at the border said. I shamefully admit that at first I mocked such rural pride.

My mind was changed one fine night when I walked out to some private, gated land near the college. I ignored the “No Trespassing” signs, found a break in the fence, and settled down on a slight hill.

As twilight gloom settled into utter darkness, I saw the Milky Way emerge, stretched across the sky like the backbone of God.

“How lucky they are to live here,” I thought. “How lucky I am that fate brought me to this place to share what they have seen.”

I must confess that when I got the job at Perkins 25 years ago, I was thrilled for very selfish reasons. I had done a thousand programs over the years for the Columbus Astronomical Society and many other groups, but the effort of carting around telescopes and slide projectors had sapped my spirit. Here was a place to store my stuff. Here was a place with a huge, honkin’ telescope. Here was a place to call my astronomical home and do my programs with relative ease and safety.

Little did I consider the burden of paperwork, the continuing need to persuade my university that Perkins fulfilled some small fraction of its educational mission, and the grinding responsibility to fulfill its fiscal needs.

When the Ohio Wesleyan provost offered me the job at quarter time, he said to me, “Tom, do whatever you like with the place as long as you can figure out a way to pay for it. Just keep the place from falling down while we figure out what to do with it.”

They were going to sell it, I suspected, probably to the owners of the golf course that surrounded it. Over the course of my first year, I was subjected to a series of visits by people in limos or expensive cars who, day and night, demanded tours of the place because they were “limited partners” in the golf course and my beloved Perkins was going to be their new clubhouse.

“Over my cold, dead body,” I remarked jovially as I gave them the tour they demanded.

Perkins’ greatest crisis came a few years later when Ohio State pulled its financial support. The task of breaking the bad news fell to the Vice Chair Jerry Newsom, to whom I offer my heartfelt thanks for breaking it so kindly.

Even though we began to charge for programs, the going was tough that first year after OSU’s withdrawal. At the end of the fiscal year, I was pretty deeply in the hole, and a fair chance remained that Ohio Wesleyan would again be tempted to sell the place.

So one dreary morning I started making phone calls. As the day wore on, the rejections produced an increasing sense of despair. One faint glimmer of hope lingered in my last phone call.

“How much do you need? I’ll transfer some stock to Ohio Wesleyan,” said Jerry Newsom. My gratitude to him was inexpressibly boundless, and it has not faded one iota as the decades have passed.

Over its 95 years, Perkins has survived not because throngs of people adored its beauty or its changing mission.

It survived because there was always at least one person like Jerry Newsom who was enthralled by its potential and was willing to make the sometimes small, sometimes large, sacrifices to keep it alive.

I am but one person in that thin but unbroken chain. As I pass from its doors, I recognize that its meaning and purpose must change to fit the vision of its next leader. It is in capable hands, and I do not regret my departure.

But my own vision has grown even more resolute than it was when I watched the moon set behind the trees so long ago.

That resolution stays steady because of a thousand magical moments as I stood beside some telescope, large or small, and watched some person, young or old, look through a telescope for the first time.

I will never forget the first time I ushered a child up to the big Perkins telescope and watched her eye light up, quite literally, as it glowed, a brilliant white orb, with the light of the moon.

Thus, look for me on the lawn at Perkins Observatory showing someone with a childlike heart the craters on the moon. I will be content to stand by some telescope showing people what their universe looks like and perhaps helping them to see their place in it on a tiny speck of spinning rock hurtling through space.

And on nights when Perkins does not have a program, look for me under some clear, dark, rural sky. Listen for the sound of third-graders clustered around a telescope. There I will be as long as my legs will hold me up and my arms are strong enough to guide a child up the ladder to the eyepiece of my old ‘scope. Look for a child’s eye ablaze with the light of the rising moon. I’ll be there.