Nicolaus Copernicus was the first to demonstrate that the earth orbited the sun, upsetting the prevailing notion that the earth was the center of the cosmos. But the Polish astronomer died in obscurity in 1543 and was buried in an unmarked grave. Five centuries later, archaeologists say they have located his long-sought resting place, under the marble floor tiles of a church.

In a sense, the search for Copernicus’ grave always led down the narrow cobblestone road into Frombork, a sleepy Polish town of about 2,500 on the Baltic coast where Copernicus lived and worked. The Frombork Cathedral, atop one of the region’s few hills, has red brick walls and a simple design. Towers built into the surrounding defensive walls, testaments to centuries of border conflicts, rise almost as high as the church, commanding a view of the town below, the Baltic Sea and sometimes a sliver of Russia ten miles to the north. A Communist-era sign with rusting planetary orbs proclaims Frombork’s former resident.

Mikolaj Kopernik (he later used the Latinized version of his name) was born in 1473 in Torun, in eastern Poland, to a comfortable merchant family. When his father died ten years later, the boy’s uncle, a bishop, oversaw his wide-ranging education, sending him to elite universities in Krakow, Bologna and Padua to prepare him for a career in the church.

In 1503, after establishing himself as a respected astronomer, Copernicus returned to Poland to work for his uncle, who found him a job as a church administrator and lawyer in Frombork. (Then, as now, it was easier to study astronomy as a hobby than to make a living at it.) From his rooms in a brick tower a few hundred feet from the cathedral’s front door, he collected rents, oversaw the region’s defenses and practiced medicine. He spent his spare time translating poetry from Greek into Latin, suggesting currency reforms, painting—and revising humanity’s sense of its place in the universe.

A 30-year project, De Revolutionibus Orbium Coelestium, or On the Revolutions of the Heavenly Spheres, was Copernicus’ response to the unwieldy mathematics used since the days of the ancient Greeks to explain the motion of the sun, moon and five known planets (Mercury, Venus, Mars, Jupiter and Saturn). Astronomers had worked from the assumption that the earth was the center of the universe, forcing them to draw convoluted orbits for the planets, which even had to reverse directions for the theory to be consistent with their observed trajectories. Once Copernicus put the sun at the center of the picture and adjusted the mathematics, the planetary orbits became regular, smooth and elegant. His inspiration came early, but the cautious scholar took half a lifetime to check his figures before publishing them in 1543, the year he died at age 70. “The scorn which I had to fear on account of the newness and absurdity of my opinion,” he admitted in the book’s preface, “almost drove me to abandon a work already undertaken.”

True to his prediction, his contemporaries found his massive logical leap “patently absurd,” says Owen Gingerich, professor emeritus of astronomy and the history of science at the Harvard-Smithsonian Center for Astrophysics and author of The Book Nobody Read: Chasing the Revolutions of Nicolaus Copernicus. “It would take several generations to sink in. Very few scholars saw it as a real description of the universe.” His book remained obscure for dec-ades. The Catholic Church censored Coelestium in 1616 only after Galileo drew their attention to it.

Copernicus’ death wasn’t even noted in the cathedral’s records. “We know when Copernicus died only because somebody replaced him” as canon of the Frombork Cathedral, says Jerzy Gassowski, an archaeologist at the Pultusk School of Humanities in central Poland. In 2004, Frombork’s bishop approached Gassowski and proposed a new search for the scientist. At least four other excavation teams, the first digging as early as 1802, had looked in vain for Copernicus’ body. A ground-penetrating radar survey showed more than 100 possible graves underneath the cathedral’s gray-and-black marble tiles. “I wasn’t enthusiastic,” Gassowski recalls. “I just thought we’d dig year after year and never find him.”

But the bishop, Jacek Jezierski, was more optimistic, thanks to a historian’s hunch that Copernicus might be buried near the altar where he prayed every day. The excavation was complicated. Digging had to stop several times a day for masses, concerts, weddings and funerals. When the workers lifted the cathedral’s marble floor tiles to dig a square pit about ten feet on a side, they found loose, shifting sand. The bass note vibrations of the cathedral’s organ twice caused the pit’s sand walls to collapse.
Two weeks of exploratory digging in August 2004 turned up three skeletons. Two were too young, and the other had been buried in a labeled coffin. Then, last summer, the archaeologists uncovered parts of more than a dozen bodies. Some were encased in coffins, others had been wrapped in shrouds long since decayed; most had been damaged or mixed up over the centuries.

In August, Pultusk archaeologist Beata Jurkiewicz carefully lifted a skull from the bottom of the pit. Forensic anthropologist Karol Piasecki said the skull, which lacked a jawbone, was that of a roughly 70-year-old male. “It was an amazing moment, but I’m a skeptical person,” says Jurkiewicz.

The researchers sent the partial skull to the Warsaw police department’s main crime lab, where police artist Dariusz Zajdel did a forensic reconstruction, the same technique police use to flesh out and help identify decomposed murder victims. From detailed measurements of the shape of the skull and its grooves and deformations, Zajdel used a computer program to create a portrait of a severe old man with a long face, a nose that had been broken decades before his death and a scar above his right eye. Subtract 30 years, and the likeness Zajdel created bears a strong resemblance to the surviving portraits of a middle-aged Copernicus, all based on a much copied self-portrait that has been lost. It was enough for Gassowski and Jurkiewicz. “When I found out who it was, I called him Nicky and treated him like my best buddy,” Zajdel says.

Still, doubts linger. “There’s a high probability it’s Copernicus, but to be sure we have to make a DNA test,” Gassowski says. The scientists would like to compare the skull fragment’s DNA with that of a descendant—but the bachelor academic had no known children. The next best chance is to test DNA from the bones of Copernicus’ uncle, Lucas Waczenrode, who was buried in the same cathedral.

Alas, Waczenrode’s burial site is also lost to history. Locating his body underneath the cathedral floor could take years—if it’s even there. In the final days of World War II, Soviet soldiers burned most of Frombork and looted the church as they marched toward Germany, and the cathedral’s crypts would have been a prime target for treasure hunters. (More than 60 years later, Frombork’s old town square is still in ruins.) Researchers plan to study church archives as well as interview Frombork residents who remember the war years to get a better fix on where Copernicus’ uncle might be buried.

The Polish team’s professional reserve—their insistence on verifying every possibility—is in keeping with the cautious nature of their quarry. In the search for a man who solved one of science’s great puzzles, perhaps it’s fitting that they want no mystery to remain.