Comet of 1618. Title page for a German book about comets, published in 1619, with an artwork showing the Great Comet of 1618 in the night sky. This was one of the most spectacular comets in history, causing much speculation and interest across Europe. It was visible to the naked eye from 6-25 September 1618, and had been discovered on 25 August 1618 using a spyglass. Below the artwork is a biblical inscription: Instabunt tempora periculosa (Second Epistle of Timothy, 3), which translates as insdangerous times shall comeins. Throughout history, comets have been considered omens of doom. This book, by the German historian and schoolmaster Gothard Arthusius (1570-1630), was published in Frankfurt-am-Main.