The book contains 181 problems, 50 questions, and 319 tests with answers and solutions. The material is mostly new, but it also includes the most successful tasks from previous editions. Overall, these are not very difficult—yet “creative”—problems that reveal different aspects of modern astronomy and space exploration and require creative thinking and understanding of the subject. Some questions are based on literary works, including science-fiction stories by the Strugatsky brothers. Working with this book makes knowledge in astronomy and space exploration more active—important for future scientists and engineers, as well as for physics and astronomy teachers.