The Moon has fascinated the mankind throughout the ages. By simply viewing with the naked eye, one can discern two major types of terrain: relatively bright highlands and darker plains. By the middle of the 17th century, Galileo and other early astronomers made telescopic observations, noting an almost endless overlapping of craters. It has also been known for more than a century that the Moon is less dense than the Earth. Although a certain amount of information was ascertained about the Moon before the space age, this new era has revealed many secrets barely imaginable before that time. Current knowledge of the Moon is greater than for any other solar system object except the Earth. This leads to a greater understanding of geologic processes and further appreciation of the complexity of terrestrial planets.
By the beginning of the 21st century, virtually all of Planet Earth has been visited, photographed, described and mapped. Now only one frontier remains to explore – space.
Present report contains some general information concerning the Moon as a planet and rather detailed description of Soviet unmanned Luna missions, which, together with American manned and unmanned missions, made an invaluable contribution into the system of our general knowledge.