It’s nice to be reminded every once in a while that we live on a planet.

That we are lodged on a wet rock spinning in cold, black, empty space and hurtling through the void, down through time like water into a storm drain.

You are not likely to notice this while waiting at a red light downtown although sometimes waiting for the thing to change will get you a glimpse of eternity. Nor are you likely to notice it on the recliner, tuning in to American Idol. Or waiting for a table at the IHOP.

Consumer culture and all of our measly daily scratching conspires to hide from us the fact that the ground under our feet is really a large bolting asteroid.

But there are places you cannot avoid the sensation.

For me, driving long distances on the prairies of Saskatchewan or Alberta will do the trick. You watch the grain elevators rise up on the horizon in front of you like the sails on a clipper ship, and watch them lower down behind you after you pass: You know you are on a sphere and every direction falls off downhill around you.

You recognize it on an airplane, too, watching miles pass under your seat like so many inches, seeing at one time Lake Superior to your aft and Lake Michigan afore. You can take in a significant arc of the planet’s circumference at 30,000 feet.

But each of these epiphanies requires that you be traveling: the moving point on a geologic ordinate and abscissa.

If you want to have the planetary feeling without racing around the globe, you can get it standing still in Arizona: with your feet planted at the edge of the Grand Canyon. In that case, you stand stock-still and let the planet do the moving.

The first time I saw sunrise at the Grand Canyon, my wife and I were camping on the North Rim outside the National Park. We had arrived with the naive assumption we could wander in late in the afternoon and get a room at the lodge. Or failing that, we could get a slot at the campgrounds.

The desk clerk took pity on us and explained that although they were completely booked, lodge and campground, for the foreseeable future, we could find a dirt road just outside the park that would take us to a place in the National Forest where people often camped.

It was dark by the time we got to that road, and when we turned into an open place where two or three other tents were set up, it was already night.

We slept, we dreamed, and we woke before sunrise, when the earliest glow floated in through our tent flap. And when we got out to stretch and start up the camp stove, we gasped: We were about 15 feet from the rim of the canyon. It dropped out of sight below us.

If we had pulled forward just a little farther the night before in the blackness, it would have been Thelma-and-Louise time for us. We were hard on the edge.

But more impressive, the humid late-July weather had left the entire canyon as a gigantic dish of cotton. The clouds filled in the canyon-hollow like apples in a fruit bowl. A 215-mile long fruit bowl.

The mists swirled and wisped below us, over precipices and down canyonlets, in constant motion, rising and subsiding as the new-hatched sun warmed patches of the air the mist rode upon and the breezes wafted the veils.

The Classical writer, Longinus, said that we enjoy the day-to-day things of our lives, but when it comes to awe, we get that only from the sublime. Hearth fires, he said, were nice, but erupting volcanoes make us consider a planet and cosmos larger than we are and well beyond our control. The sublime is beautiful, but it is also scary: It is the source of religious feeling.

You cannot avoid that at the Grand Canyon, with its stony layers of eons piled upon each other. The Canyon is a great wound in the Earth into which we can look and see its organs pulsating at a rate so slow as to make all of human history a mere blip on its EKG.

Sunrise is always a magic time. For me, all the more magic for how seldom I see it, being a night person and late-riser during every time of the year except vacation. Familiarity has not had a chance to dull the morning’s effect for me: Every dawn I witness is a rebirth.

The following summer, we came to the Canyon again, to the South Rim. We camped outside the park once more, and got up at 3 in the morning to drive to the rim to see the whole process of sunrise.

Even in July, it was cold in the dark. We parked at Lipan Point, where we would be able to see northeast into the canyon, where the sun should pop up. With a flashlight, I set up my 4X5 camera, with its bellows and tripod, and pointed it down into the blackness below.

By 4 a.m., the glow on the horizon widened into a band of dull brightness. I managed to focus the camera on the now-visible horizon line, and then pointed it back down into the ink.

A minivan pulled into the turnout and a few people got out, looked around at the black hole, and deciding there was nothing to see, got back in and drove off.

I moved the camera over the restraining fence and out onto a rocky knob with an unhindered view. My wife fretted I might slip off the cliff and down into the hard centuries of geology below: A very physical way to meet eternity.

By the time I got the camera set, the glow from the horizon had made the rock below us seem less like the river Styx and more like a darkened charcoal drawing. It was beginning to take on detail. I made an exposure of five minutes or so, to try to get some of the charcoal registered on my film. 

The river below us began to reflect the lightening sky and became a glowing white streak in the sooty rock. It pointed in one direction northeast directly at the place the sun would arise, in the other direction, it curved around the coal-colored cliffs and disappeared.

The moment the sun broke the horizon, though, was the moment we realized we were sitting on a spinning round rock: The effect is unsettling and eerie.

I’ve had this happen a few rare times in my life. When the sun is still in contact with the horizon, its motion is quite noticeable. You can actually see it move.

But at that moment, the sun stopped moving, just as if Joshua had commanded it. And as the sun stopped, the Earth like a giant machine, whirring its gears began rotating forward in front of us, lurching from under our feet. An earthquake wouldn’t have felt more tactile.

It was as if we were coming over the top of some giant Ferris wheel. The still sun made our motion all the more apparent. It was Einstein in action: relativity made palpable. A shift in frame of reference.

The rock we were reeling on, trying to keep our balance, was pulling forward toward the sunrise.

”Whew! What was that?”

It didn’t take long, though, after the disc of the sun broke free from the horizon, all that motion ceased. The common light of day had re-inaned the world. We would eat breakfast, talk about baseball, read the newspaper all the quotidian fuss of our lives and rejoin the society where the search for a good five-cent cigar seems important.

A friend was telling me once about the trouble he has been having with his insurance company. He had run into a bureaucratic Catch-22 in which he needed an official letter before the insurance would take effect, but couldn’t get the letter until the insurance was working.

”Sometimes, I don’t know how the world keeps turning,” he said.

As we fight rush-hour traffic, heat up our Pop Tarts, pay our bills, worry if our taxes will devour our raise or if Congress will ever become more than monkeys squabbling over a banana;

As we worry if our daughters will safely negotiate the pitfalls of adolescence, if the rebuilt transmission can last another 30,000 miles, and we put a few more dollars into an IRA;

As we submerge ourselves once again into the inclarity of what we call our lives, it’s good to remember that there is something larger out there, with a wider frame of reference.

We need to be reminded every once in a while that we live on a planet.