Baltimore isn’t my city. I work here a few days a week, then start the long drive home to Annapolis.

Until I spotted Baltimorehenge.

The sun lined up just so in the west, sending a shaft of light down East Lombard Street, glowing from the Bromo Seltzer Tower on the horizon directly through my windshield at Calvert Street. It threw the city’s urban canyon of tall buildings into silhouette.

Drivers, blinded like me by the glow of the approaching equinox, were fixed in place until they could adjust their visors or scramble for a pair of sunglasses.

I wonder if Wendel Bollman, the railroad engineer who laid out Lombard Street 148 years ago, planned this celestial alignment. I doubt it. Engineers put function over form and his goal was building a bridge over the Jones Falls.

Stonehenge, the megalithic structure on the Salisbury Plain in England, might be the most famous human construction with an astronomical alignment. Its sarsen and bluestone megaliths channel the rising sun at the winter and summer solstices.

The east-west street grids of Manhattan and Chicago create their own modern henges.

Others have spotted Baltimorehenge, but my first sight of it reminded me that even in a weary commute, the renewed light of spring turns the mundane into something glorious.

I’m a columnist, not a photojournalist. I take photos for my job, mostly trying to mimic shots by photographers far better than me. That’s good enough.

But there’s something about March light that makes me want to capture how it glows, the day chasing the retreating boundary of night.

The equinox is the spot on the celestial calendar when light and dark balance, considered by many to be the start of spring. You could just as easily say it’s March 1st or when the osprey return to the Chesapeake Bay.

We officially marked it this year at 5:04 a.m. Thursday, but at this spot on the globe, the tipping point came Sunday. Few noticed the difference.

The angle of the sun affects the light as well. It’s directly over the equator now in its arc across the sky, but this far north, we see it at an oblique 51 degrees. The path will rise in the sky as the earth continues its tilt.

Long before it reaches its peak of 77.5 degrees at summer solstice, the light of dusk and dawn will be filtered green by an expanding canopy of leaves.

Then, on its slow decline back to 23.5 degrees in fall, those leaves now russet and gold, will give the world a different hue.

The astronomical equation gives us March light, the purest form I know.

It’s gold on Lombard Street at sunset and above the Chesapeake Bay at sunrise. It lights up Annapolis Roads — that wide expanse south of the Bay Bridge where container ships wait for a spot at the Port of Baltimore.

Human beings have long celebrated the return of light in the spring.

That’s the theory of Stonehenge. People see it as an astronomical device marking the spiritual significance of winter’s depth passing.

Once, I walked inside Newgrange. Archaeologists believe the prehistoric monument was designed to admit a creeping glow of sunrise at the winter solstice for people who built it as a tomb in Ireland’s Boyne Valley.

I was there in another March and made do with a light bulb simulation. Crowded with others in its darkness, I saw the significance of returning light for people without electricity to make their own.

Or maybe the builders were like Wendel Bollman, a man with a river to cross and a job to do, and never noticed what they’d accomplished until someone pointed it out.

Neil deGrasse Tyson, the avuncular famous physicist, first described the alignment of New York streets as Manhattanhenge 30 years ago. He wondered what future archaeologists might think.

“Surely they will presume the grid had astronomical significance, just as we have done in the case of that prehistoric circle of large vertical rocks known as Stonehenge,” he wrote.

The late amateur astronomer Herman Heyn is credited with calculating the phenomenon in Baltimore, one achievement in a lifetime of gazing up from the city’s streets.

On the equinox, the sun sets at due west. Heyn discovered that Baltimore’s street grid is a few points off true north, shifting his city’s solar alignment by a few days.

The Baltimore Sun first reported Heyn’s discovery that March 12 marks the spring sun bursting through Baltimorehenge. What I spotted March 13 might not have been the full effect.

Next week, you can catch the sunrise version if the skies are clear at 7:01 a.m. Tuesday. Or wait until the fall, when the phenomenon repeats on Sept. 18 and 29.

For now, my evening commute is less glaring, if less remarkable. I suppose the flashing digital billboards of East Lombard will suffice as sights in the sky.

Seeing the spring sun shine down the long street that day made me feel a little more rooted in Baltimore. A little less out of place.

Even if Annapolis is my city, and I have miles to go before I’m home.