Girolamo Fracastoro (Verona, ca. 1476-1478, Affi, 6 August 1553) was an Italian physician, philosopher, astronomer, geographer and man of letters. Colleague and friend of Nicolaus Copernicus, Fracastoro was also a professor of logic at the University of Padua. He was archivist to Pope Paul III, to whom he dedicated the astronomical work Homocentrica (1538). The lunar crater Fracastoro is dedicated to him. He is one of the founders of modern pathology. As an astronomer he was the first to discover, with Pietro Apiano, that cometary tails always appear along the direction of the Sun, but in the opposite direction to it. In 1538 he described an instrument with an astronomical function, then perfected by Galileo Galilei tens of years later: the telescope. Adams F, 817; Durling 1631; Wellcome I, 2396; Houzeau-L. 2455; Bau Girolamo Fracastoro (Verona, ca. 1476-1478, Affi, 6 August 1553) was an Italian doctor, philosopher, astronomer, geographer and man of letters. Colleague and friend of Nicolaus Copernicus, Fracastoro was also a professor of logic at the University of Padua. He was archivist to Pope Paul III, to whom he dedicated the astronomical work Homocentrica (1538). The lunar crater Fracastoro is dedicated to him. He is one of the founders of modern pathology. As an astronomer he was the first to discover, with Pietro Apiano, that cometary tails always appear along the direction of the Sun, but in the opposite direction to it. In 1538 he described an instrument with an astronomical function, then perfected by Galileo Galilei tens of years later: the telescope. Adams F, 817; Durling 1631; Wellcome I