VENUS

As he has done in Saturn . . . and Mars . . ., Asimov uses the description of a single astronomical object to relate much basic astronomy in a direct, easily understood manner. The text presents a significant amount of the content of an introductory astronomy and planetary physics course clearly, and without mathematics. The wealth of figures and tables complements and clarifies the descriptions of the relative sizes of the planets when viewed from different distances, the orbital characteristics of planets and satellites, and the appearance of objects as viewed by an observer located on another planet. Most of the astronomical history and observations that constitute the story of Venus have been described before. However, Asimov uses new data, particularly from Pioneer Venus (launched in 1978), to show that astronomy is an alive scientific field, with many theories to be tested and observations to be explained. The ploy of seeing the night sky as a Sumerian astronomer did, and following the development from astronomical observation to theory, works well in leading beginners from their own casual observations of the skies to an understanding of the elementary theories. The book's subtitle is initially confusing; however, the confusion ends when Asimov takes up the description of Mercury, asteroids, and comets—other near neighbors of the sun—in the last four chapters. As a bonus, readers lulled by the regularity of terrestrial phenomena might modify their mundane geocentric world-view; the realization that there are other, comparatively bizarre phenomena (e.g., the playful, hesitant sunrises that can occur on Mercury's surface) may surprise many readers, and start them wondering about the universe.