September 23 in History: Neptune's Discovery and the Art of Cosmic Detective Work

There are days on the calendar that feel like they were drawn with a ruler, and then there are days like September twenty-third. On this day in 1846, an astronomer in Berlin pointed his telescope at a specific patch of night sky, and found a planet that, until that very moment, had only existed on paper. We now know what they didn’t, of course—we have photographs of Neptune, we know its storms and its moons. But they were standing at the edge of the known solar system, with nothing but mathematics as their guide. Just yesterday, we were talking about the day after empires fall, about the first steps taken into a new and uncertain world.

Well, September twenty-third is a day of drawing new maps—for the heavens, for continents, and for the perilous new landscape of global power. Let’s stay with that planet for a moment. Because the discovery of Neptune is just… it’s one of the most beautiful stories in all of science. It’s a detective story, played out in the silent, clockwork motion of the cosmos. For years, astronomers had been puzzled by Uranus. Its orbit wasn’t quite right. It wobbled. It strayed from the path that Newton’s laws of gravity said it should follow. Something was pulling on it. Some unseen, massive object, lurking out there in the dark.

Now, you have two ways of looking at a problem like that. You could decide that Newton’s laws are wrong, that on the grand scale of the solar system, gravity works differently. Or… you could decide that the laws are RIGHT, and that there must be something else out there, something you haven’t found yet, that accounts for the discrepancy. A French astronomer named Urbain Le Verrier chose the second path. He chose faith in the physics. And he sat down with a pen and paper and began one of the most extraordinary calculations in history. He worked backwards. If there is an eighth planet, and it’s causing Uranus to behave this way, then based on the size of the wobble, that unseen planet must have a certain mass.

And if it has that mass, it must be orbiting at a certain distance and a certain speed. And if all of that is true… then right now… tonight… it should be… right… there. He finished his calculations and sent a letter to the Berlin Observatory, to an astronomer named Johann Gottfried Galle. He basically said, "Dear Sir, would you be so kind as to point your telescope at this specific spot? I believe you may find a planet." The sheer confidence is breathtaking. Galle got the letter on September twenty-third, 1846. That very night, he and his assistant aimed their telescope where Le Verrier told them to look.

And within a single degree of the predicted position, they saw a tiny, faint disc that wasn’t on any of their star charts. It was Neptune. They found a world with math. They knew it was there before they saw it. Isn’t that just delightful? It’s the universe revealing one of its secrets, simply because someone asked the right question and trusted the numbers. Forty years before that, on this same day in 1806, another kind of map was being completed, not of the stars, but of the earth beneath our feet. Meriwether Lewis and William Clark paddled into St. Louis, Missouri, and brought their legendary expedition to a close.

Can you imagine the scene? For over two years, they had been gone. Vanished into the vast, unmapped territory of the Louisiana Purchase. Many people assumed they were dead—lost to disease, to accident, to the sheer, overwhelming scale of the continent. And then, on September twenty-third, they just… reappear. Coming down the river. Alive. They had done it. They had gone all the way to the Pacific Ocean and back again. The city erupted in what was described as "much public excitement." Which feels like a wonderfully understated way of saying that everyone completely lost their minds. Think about what they represented, pulling up to the shore that day.

They were living ghosts, returning with stories that would redefine America's idea of itself. They brought back journals filled with sketches of plants and animals no one in the East had ever seen. They brought back maps, hand-drawn, charting the great rivers and mountains that stood between the settled states and the western sea. Before them, that land was a question mark, a myth. After them, it was a place. A real, tangible, and—for better or for worse—achievable destination. They had walked into the blank spaces on the map and filled them in, step by grueling step. While Le Verrier would later map a world with his mind, Lewis and Clark mapped one with their feet.

Both, in their own way, expanded the world for everyone who came after. And even before that, we have another kind of journey, another kind of defiant exploration. On September twenty-third, 1779, off the coast of England, the Scottish-born American naval commander John Paul Jones, found himself in a truly desperate fight. He was commanding a repurposed French merchant ship, renamed the Bonhomme Richard, and he was up against two British warships, the Serapis and the Countess of Scarborough. This was not a fair fight. The Serapis was a newer, faster, more heavily armed vessel. The battle was, as the records say, "hard-fought." A brutal, close-quarters slugging match that lasted for hours, into the night.

Jones's ship was shattered. It was on fire, sinking, with casualties mounting. The British commander, seeing the absolute carnage, called over to ask if Jones was ready to surrender. And from the deck of his burning, sinking ship, Jones is said to have given the immortal reply: "I have not yet begun to fight!" And he hadn't. He managed to lash his ship to the Serapis, and his marines and sailors boarded the British vessel and captured it. Jones won the battle by losing his own ship and taking the enemy's. He sailed away in the Serapis. It’s the perfect symbol of the American Revolution, isn't it? A scrappy, outmatched force, refusing to quit, and winning through sheer, stubborn audacity.

It was a victory that had little strategic impact on the war itself, but its psychological impact was immense. It announced that the new American navy, small as it was, was a force to be reckoned with, right in Britain's own waters. This day also gave us a spectacular collection of people who, in their own ways, also refused to surrender. September twenty-third is a day of remarkable births. Bruce Springsteen was born on this day in 1949. "The Boss." A man who has spent fifty years writing the story of American life—the hopes and the failures, the highways and the dead-end towns. His empire is one of music and storytelling.

And on this day in 1869, the anarchist and activist Emma Goldman was born. A woman who fought her entire life against the empires of state power, of capitalism, of any institution that she felt crushed the human spirit. She was considered one of the most dangerous women in America for a time. Then you have Helen Keller, born in 1880. A woman who overcame the profound isolation of being deaf and blind to become a world-famous author and activist for disability rights and women's suffrage. She built a bridge from her silent, dark world to the rest of us, and then used that bridge to fight for others. And you have Paul Laurence Dunbar, born in 1872, one of the very first African American writers to achieve national prominence.

He used poetry, novels, and short stories to give voice to the experiences of Black America in the decades after the Civil War, navigating a world that was still so profoundly hostile. Even Hasan Minhaj, the comedian, born in 1985. He uses humor to dissect and explore the complexities of being Indian-American, of being Muslim in a post-9/11 world, taking on biases and stereotypes with a microphone and a smile. Each of them, in their own field, looked at the world they were given and said, "No, it can be different." They drew new maps of what was possible. But back to the world of presidents and global politics.

September twenty-third gives us two moments, just five years apart, that show the profound shift in the mid-twentieth century. The first is almost comical. It’s 1944. Franklin D. Roosevelt is running for his fourth term as president, in the midst of World War Two. And his political opponents, looking for any angle of attack, started a rumor. The rumor was that on a recent trip to the Aleutian Islands, Roosevelt had accidentally left behind his beloved Scottish Terrier, Fala. And that he had then, scandalously, sent a Navy destroyer all the way back to retrieve the dog, at immense taxpayer expense. It was a silly, baseless attack.

But instead of ignoring it, FDR met it head-on in a campaign speech. He said, you know, the Republican leaders have attacked him, and his wife, and his sons, and that’s fine. But then he gets this wonderful, knowing smile in his voice. He says, "But now, they’ve gone too far. They have attacked my little dog, Fala." He goes on to say that Fala’s "Scotch soul was furious" at the slander. The audience roared with laughter. It was a masterful piece of political theater. He used this absurd personal story to paint his opponents as petty and ridiculous, all while reminding everyone of his own humanity and humor during a dark, difficult war.

Now, fast forward just five years. September twenty-third, 1949. The war is over. FDR is gone. And his successor, Harry S. Truman, has an announcement to make. There is no folksy humor this time. His statement is described as "surprisingly low-key and carefully worded." He announces to the American people, and to the world, that the Soviet Union has successfully tested its own atomic bomb. Just like that, the American nuclear monopoly was over. The Cold War, which had been a conflict of ideology and influence, now had the clear and present danger of mutual annihilation at its core. In 1944, the president’s biggest public worry was a political jab about his dog.

In 1949, it was the reality that another global superpower now wielded the power to destroy the world. You can feel the temperature of the planet drop in that five-year gap. The age of anxiety had truly begun. One announcement, delivered quietly, redrew the map of global terror forever. And then, because history is never just one thing—it’s never just grand or just terrifying—it’s also profoundly, deeply strange. On September twenty-third, 2016, a small, carved wooden box went up for auction in California. Inside the box were a portion of the cremated remains of the author Truman Capote. Yes, his ashes. They had been kept by his friend Joanne Carson, Johnny Carson's ex-wife, and after she passed away, her estate decided to sell them.

After twelve bids, the box containing a piece of the author of "In Cold Blood" and "Breakfast at Tiffany's" sold for forty-three thousand, seven hundred and fifty dollars. What do you even do with that? It’s a bizarre, almost unbelievable little footnote. But it’s also a very modern kind of story, isn't it? A reflection on celebrity, on legacy, and on our strange desire to own a physical piece of the stories we love. Someone, somewhere, decided that a tangible connection to Truman Capote’s genius—or at least, his person—was worth the price of a decent car. It’s a strange way to draw a map, not of a continent or the stars, but of our own culture’s obsessions.

So when we look back at this one day, September twenty-third, we see the horizon of our world expanding in every direction. It’s pushed outward by a telescope, revealing a new planet. It’s stretched across a continent by explorers returning home with maps and stories. It’s defended with impossible defiance in a sea battle. And it’s also darkened, pulled inward, by the terrifying knowledge that we are no longer alone in our most destructive capabilities. History’s value is always right now. It’s in seeing that the world has been redrawn countless times. And that amidst the grand, sweeping changes, the things that often resonate the most are the small, human details.

A president defending his dog. A captain refusing to surrender. The sheer delight of finding something new, right where you calculated it would be. Those are the moments that remind us that history was lived by people. People who were standing on their own shore, looking out at an unknown sea, and deciding to set sail anyway.