FROMBORK, Poland - Nicolaus Copernicus, the 16th-century astronomer whose findings were condemned by the Roman Catholic Church as heretical, was reburied by Polish priests as a hero on Saturday, nearly 500 years after he was laid to rest in an unmarked grave.

His burial in a tomb in the cathedral where he once served as a church canon and doctor indicates how far the church has come in making peace with the scientist whose revolutionary theory that Earth revolves around the sun helped usher in the modern scientific age.

Copernicus, who lived from 1473 to 1543, died as a little-known astronomer working in what is now Poland, far from Europe's centers of learning. He had spent years laboring in his free time developing his theory, which was later condemned as heretical by the church because it removed Earth and humanity from their central position in the universe.

His revolutionary model was based on complex mathematical calculations and his naked-eye observations of the heavens because the telescope had not yet been invented.

After his death, his remains rested in an unmarked grave beneath the floor of the cathedral in Frombork, northern Poland, the exact location unknown.

On Saturday, his remains were blessed with holy water by some of Poland's highest-ranking clerics before an honor guard ceremoniously carried the coffin through the imposing red brick cathedral and lowered it back into the same spot where part of his skull and other bones were found in 2005.

A black granite tombstone now identifies him as the founder of the heliocentric theory, but also a church canon, a cleric that ranks below a priest. The tombstone is decorated with a model of the solar system, a golden sun encircled by six of the planets.

At the urging of a local bishop, scientists began searching in 2004 for the astronomer's remains and eventually turned up a skull and bones of a 70-year-old man - the age Copernicus was when he died. A reconstruction made by forensic police based on the skull showed a broken nose and other features that resemble a self-portrait of Copernicus.

In a later stage of the investigation, DNA taken from teeth and bones matched that from hairs found in one of his books, leading the scientists to conclude with great probability that they had finally found Copernicus.

In recent weeks, a wooden casket holding those remains has lain in state in the nearby city of Olsztyn, and on Friday they were toured around the region to towns linked to his life.

The pageantry comes 18 years after the Vatican rehabilitated the Italian astronomer Galileo Galilei, who was persecuted in the Inquisition for carrying the Copernican Revolution forward.

Saturday's Mass was led by Jozef Kowalczyk, the papal nuncio and newly named primate of Poland, the highest church authority in the deeply Catholic country.

Copernicus' major treatise - On the Revolutions of the Heavenly Spheres - was published at the very end of his life, and he only received a copy of the printed book on the day he died - May 21, 1543.