This challenging collection of problems is organized into seven carefully crafted, thoughtful chapters on the Sun and the nature of the solar system; the motion of the planets; the Sun, Earth, and Moon; the sky as observed from the rotating, revolving Earth; other planets, their satellites, their rings; asteroids, comets, and meteoroids; and the radiations and telescopes. From question 1, "List characteristics of the solar system that are major clues in devising a hypothesis of its origin and evolution," through question 924, "Give a brief list of the contributions of radio and radar technologies in lunar and planetary astronomy," the problems range in difficulty from ones requiring only simple knowledge to ones requiring significant understanding and analysis. Many of the answers, in turn, illuminate the questions by providing basic explanations of the concepts involved.

Pioneer 10 and 11 are now halfway to the edge of the solar system. All beginning and advanced students of astronomy and their instructors as well as all dedicated amateurs can join James Van Allen on this journey by exploring the questions and answers in this stimulating book.