Not long ago, far too recently, I was startled to discover that Dr. Neil deGrasse Tyson was black.

I was more than startled. I was startled, embarrassed and delighted.

Who is Tyson? For those of you who have been living on the moon (or in Hysham), Tyson is one of the best known scientists on the planet. He is certainly the most famous astrophysicist since Carl Sagan.

Tyson is the can-do-everything guy who makes the rest of us hate ourselves for not being him. Hollywood good looking, a nationally acclaimed scientist, a gifted college athlete, Tyson was a best-selling author with Isaac Asimov’s gift of rendering science fascinating to the layman. He’s  a guy who could have been a U.S. senator, a movie star or Bill Gates.

So, why didn’t I know Tyson was black?

Pure bigotry.

I followed Tyson’s column in “Natural History” magazine for years. The column runs without a picture. I pictured the author as an old white dude with disheveled hair and  thick glasses - a stereotype cut from the same cloth as the old images of blacks eating watermelon, Mexicans asleep under huge sombreros, big-nosed Jews, drunken Irishmen, stingy Scots and Betty Boop bimbos.

The dusty image of the absent-minded professor proved there was still junk in my attic after decades of house cleaning. It’s amazing how much rubbage an attic can hold. Mine once contained stock enough to fill a garbage barge.

Growing up in a small Montana town, I was 6 when I first saw a black man not wearing a railroad porter or conductor’s uniform. My best friend and I spotted this curiosity coming out of the post office. One of us (or maybe both of us) shouted NIGGER!

The word exploded on the small town’s main street. The earth shook. The sun dimmed and lightning rent the air.

My friend and I wheeled and ran as fast as we could. We ran until our lungs burned and sides ached. Then we ran some more, never looking back. When we collapsed in the weeds at the edge of town, we were relieved that no one was chasing us.

Looking back, I wonder who or what poisoned the young minds of my friend and me. The answer is both obvious and ethereal. The toxin was in the water, in the air, in the warp and woof of American culture. It was part of the white Jesus on the chapel wall, nasty racial jokes, Amos and Andy on the radio and the absence of color in  politics, the movies, newspapers, even athletics. Thank God, it was not in our genes.

Children of the 1960s attended colleges in record numbers. And, yes, the universities were filled with liberal atheist professors. We came of age listening to Stokely Carmichael, Malcolm X, Martin Luther King Jr. and H. Rap Brown. We set our watches ahead 10 years and evolved.

Still, I was shocked to meet the oppressed face to face. Walking the board sidewalk of the backwater town of Duck Hill, Miss., I met a group of black teens. Prepared to step aside and allow the crowd to pass, I was taken aback when the entire crew abandoned the sidewalk to make way for a single white man.

My evolution was rewarded in the 1980s when I attended parents’ night at my youngest son’s school. The teacher had the children lie on the floor while she traced their outlines on butcher paper. The pupils then colored the cutouts. After I found my son’s effigy, he challenged me to find his friend’s life portrait.

My boy’s friend, Rocky, was Nicaraguan, by far the biggest kid in class, and dark skinned. Rocky was proud of his color and had laid it on in black crayon. I smiled and pointed.

Somewhat miffed that I had found Rocky’s image so quickly, my son said, “Oh, yeah. You recognized his plaid shirt.”

Damn. We had raised a colorblind kid. Attic cleaning was its own reward. This was a bonus.

Barack Obama’s election as president capped America’s early adolescence. It was a pivotal point in American history. We’ve come a long way, but we still have a long way  to go. The same election stripped gays of an established right to marry in California. Homophobia is powerful enough in Wyoming to leave a frail young man’s corpse hanging from a fence. Montana elected the first woman to Congress. Nearly three-quarters of a century has passed and we have not elected another.

Discovery of  Neil deGrasse Tyson’s blackness reminded me that there’s still trash cluttering my own attic.