The book is devoted to modern problems of astronomy: from the study of the moon and planets to the search for gravitational waves, dark matter and dark energy. Scientists of the State Astronomical Institute . P. K. Sternberga (MSU) talk about what are the most important events in astronomy at the turn of the new millennium and what unsolved problems researchers are now working on ... The conditional historical boundary - the beginning of the new millennium - was marked by several important discoveries in the study of the Universe. Therefore, recent years can without exaggeration be called the great decade of astronomy, perhaps the beginning of its new “golden age”. The "Appendix" contains extensive reference material. The book is addressed to high school students, students and teachers, as well as to all those interested in the problems of modern natural science.