Description

Three comets appeared in the skies over Europe in 1618, a phenomenal series of events that ignited a debate about the nature of these celestial bodies and the implications of their appearance for the Aristotelian theory that celestial bodies were unchanging and “incorruptible.” In 1619, the Jesuit astronomer and mathematician Orazio Grassi published under a pseudonym his treatise on the comets, in which he upheld the established view of celestial bodies as unchangeable and orbiting the Earth. Already under attack for his defense of the theories of Copernicus, Galileo Galilei ...