Nicolaus Copernicus (February 19. 1473 – May 24. 1543) was a Polish mathematician and astronomer who, like Galileo Galilei, said that the Sun is in the center of the Solar System and not the Earth as the Catholic Church said at that time.
His casket can be seen in the window on the floor in the Archcathedral Basilica of the Assumption of the Blessed Virgin Mary and St. Andrew.
On the gravestone you can also see the Sun and 6 planets of the Solar System known at that time (Mercury - Venus - Earth - Mars - Jupiter and Saturn).