452 years ago today, on January 10, 1573 (December 7, 1572 in the lunar calendar), German astronomer and doctor Simon Marius was born. On January 10, 1573, German astronomer and doctor Simon Marius was born. Simon Marius (born on January 10, 1573 in Gunzenhausen, Bavaria, Germany, and died on December 26, 1624 in Ansbach) was a German astronomer and doctor. Simon Marius in Mundusiovialis studied in Heilsbronn from 1586 to 1601. He had already shown a genius in mathematics and astronomy at school. He gained reputation through the publication of his observations of the comet in 1596 and the publication of astronomical tables in 1599. In 1601 he was appointed court mathematician to the Count of Ansbach. He went to Prague to learn the observation techniques of Tycho Brahe. But Tycho died just four months after his arrival. He then studied medicine at the University of Padua in 1605. He was one of the scholars close to Galileo Galilei. In 1604 he observed a comet, and his students published the structure of his observations. He then returned to Ansbach. As a court mathematician (actually an astrologer), his task was to compile the annual "prophecies". In 1609, he published the first translation of the German Euclid Geometrical Origins from a Greek original. In 1610, he discovered Jupiter's four large moons independently of Galilus. Galileo accused him of copying his own research. Marius 'pupils had already published a manuscript of Galileo under their own names, and Marius was said to have intervened in the process. However, Marius later suggested naming the four moons Galilean. Galileo originally intended to name the four moons after members of the Medici family, but this suggestion was not adopted. The discovery of these four satellites was a miracle at the time because they were like a small solar system. They played an important role in the victory of sun-centered theory over earth-centered theory. He discovered sunspots independently of other astronomers. In 1612, he observed the Andromeda Galaxy, the closest galaxy to the Milky Way. Marius seemed to have known that Persian astronomer Sufi had described the galaxy around 905, so he did not claim to be its discoverer. However, it was not until 1923 that Edwin Hubble used the Mount Wilson Observatory's 2.5-meter telescope to prove that it was a stellar system outside the Milky Way. With the naked eye, it looks like a small cloud, almost no different from a star of magnitude 5. Comment: The International Astronomical Union named a crater on the moon after him ~