This book discusses the role of celestial navigation and astrology in medieval seafaring explorations, as well as the decline of astrological practices in Europe and the Islamic Golden Age. It highlights the contributions of explorers such as Prince Henry the Navigator and Ahmad Ibn Majid, as well as astronomers like Al-Khwarizmi and Tycho Brahe. The decline of astrology is attributed to factors such as skepticism, scientific advancements, and religious scrutiny. Overall, the passage highlights the intertwining of astrology with human history and the shift towards a more scientific understanding of the cosmos.