Miguel Á. Granada is Emeritus Professor of History of Renaissance Philosophy at the University of Barcelona. His publications include El debate cosmológico en 1588: Bruno, Brahe, Rothmann, Ursus, Röslin (Bibliopolis, 1996), the edition of Christoph Rothmann’s Discourse on the Comet of 1585 (Brill, 2014) with Adam Mosley and Nicholas Jardine, and Giordano Bruno, ‘De immenso’: Letture critiche (Fabrizio Serra, 2020), coedited with Dario Tessicini. Patrick J. Boner is a Visiting Scholar in the School of Philosophy at the Catholic University of America. He is the author of several studies on early modern science, including Kepler’s Cosmological Synthesis: Astrology, Mechanism and the Soul (Brill, 2013) and Kepler’s New Star (1604): Context and Controversy (Brill, 2021).

• PrefaceList of FiguresSymbols of Planets and Zodiacal Signs: Criteria of This EditionIntroductionMiguel Á. Granada1 The impact of the Comet of 1618 in Europe and Württemberg2 Maestlin’s Treatise on the Comet of 16183 The Comets of 1618–1619 and Maestlin’s Observations4 The Treatises of 1578 and 1580: A Mathematical and Astronomical Approach5 From 1578 to 16186 Bartholomaeus Keckermann and His Assault on Celestial Comets7 Maestlin’s Reply to Keckermann and the Partial Preservation of Aristotle8 Sunspots and the Telescope Appear on the Scene9 Maestlin, Schickard and Habrecht on Faulhaber and the RosicruciansMichael Maestlin, Astronomischer Discurs von dem Cometen, so in Anno 1618, im Nouembri zu erscheinen angefangen und bis inn Februar dis 1619 Jars am Himmel noch gesehen wirtCritical edition by Miguel Á. GranadaMichael Maestlin, Astronomical Discourse on the Comet that First Appeared in November 1618 and Can Still Be Seen in the Sky in February of this Year 1619Translation by Patrick J. Boner, notes by Miguel Á. Granada and Patrick J. BonerChapter 1. More Than One Comet Appeared in the Previous Year 1618Chapter 2. On the First Emergence and Appearance of This CometChapter 3. On the Course of This Comet, and the Signs and Constellations through Which It PassedChapter 4. That the Philosophers Are Divided in Opinion over Whether Comets Are Elementary or Ethereal, That Is, Whether They Are Generated and Brought into Being Here Below in the Air or High above in the HeavensChapter 5. Whether and How We May Find a Solution for the Two Opposing OpinionsChapter 6. Whether Our Present Comet Possessed Any Sensible Parallax or Not, and How Far Away It May Have Been from the EarthChapter 7. That before This Time Many Other Comets Appeared and Were Observed Not in the Air, but in the Upper HeavenChapter 8. What Aristotle and Other Philosophers Might Have Been Missing That Led Them to Think About Comets the Wrong WayChapter 9. Several Questions Concerning Comets in General, and What Follows from ThemAppendix 1. Can Comets Be Predicted?Appendix 2. Draft of a Letter to Duke Johann Friedrich to Apologize for the Delay in Presenting the Requested ReportBibliographyIndex of Biblical PassagesIndex of Names