Álvar Núñez Cabeza de VacaCabeza de Vaca (ca. 1490–ca. 1559), an early explorer of the Americas, published his Relación, the narrative of his experiences, in 1542. Historians have long debated whether his transcontinental journey began in 1534 or 1535. Cabeza de VacaCabeza de Vaca refers to a new Moon (Spanish: primero dia de luna) on the first day of September (primero de Setiembre) and mentions waiting for the next full Moon (luna llena) to begin the journey, but he does not specify the year. Previous authors, even after consulting astronomers, could not match this text to either 1534 or 1535. Were these modern scholars using the wrong calendar? Can we use the correct ecclesiastical calendarCalendarsecclesiastical from the 1500s, along with other primary sources, to offer an explanation that perfectly matches Cabeza de Vaca’sCabeza de Vaca account? Is the correct year 1534 or 1535? In the 1600s scientists such as Galileo and Christiaan Huygens concerned themselves with questions of priority, that is, credit for making a discovery. They first published their breakthroughs in anagrams sent to fellow scholars. This method could “publish the truth without revealing it.” What were the anagrams related to discoveries of the ring around Saturn, a moon revolving around Saturn, and the phases of Venus? William Hamilton served as British ambassador to the Court of Naples, Italy, from 1764 to 1798 and during this time made hundreds of visits to nearby Mount Vesuvius. Scientists regard his collected writings as the first modern work of volcanology. Hamilton also included two reports of strong meteor activity at the times of great eruptions of Vesuvius in 1767 and 1779. Can we use the dates in Hamilton’s letters to match his reports with any of the now well-known meteor showers: Perseids, Geminids, Orionids, Leonids, or Lyrids? Do Hamilton’s pioneering accounts rank as the earliest known European observations of some of these meteor showers?