Malta · 550th birthday of Nikolaus Kopernikus

Nicolaus Copernicus was born in Thorn, now Toruń in Poland. At the time, the city belonged to Royal Prussia within the Kingdom of Poland. He studied, among other subjects, in Kraków (Krakau) and at several Italian universities. In addition to astronomy and mathematics, he studied canon law and medicine. He later served as a canon in the Prince-Bishopric of Ermland and assumed ecclesiastical, economic and administrative duties there. He spent a large part of his life in Frombork (Frauenburg).

In European astronomy, the geocentric system based on ancient ideas dominated during his time. According to this system, the Earth rested at the centre, while the Sun, Moon, planets and fixed stars revolved around it. To explain the observed planetary movements, astronomers used a complicated system of circular orbits and additional auxiliary circles.

Copernicus set against this a mathematically elaborated heliocentric model. In it, the Earth moves around the Sun annually and at the same time rotates daily on its axis. The apparent daily movement of the heavens could thus be explained as a consequence of the Earth’s rotation. The planets’ temporarily retrograde apparent motion also became understandable as a perspective effect resulting from the different orbital movements of the Earth and the planets.

Copernicus published his ideas in his principal work, “De revolutionibus orbium coelestium”, which was not printed until near the end of his life. His model did not yet correspond to modern astronomy: Copernicus adhered to uniform circular motion and still required auxiliary circles. Johannes Kepler later replaced these with elliptical orbits; the observations of Galileo Galilei and the physics of Isaac Newton contributed to the further substantiation of the new view of the world.

The Copernican doctrine fundamentally changed the position of the Earth in astronomical thought over the long term and became a starting point for early modern science. The anniversary of his birth therefore provided a commemorative occasion understandable throughout Europe. No particular direct connection between Copernicus and Malta is apparent from the coin’s commemorative occasion.