The moon is original decoration of the night sky. It not only natural satellite of Earth, but also the closest to us celestial body. Watching the Moon, many people involuntarily ask a question: if it is so close then why does not fall to the Ground?
As well as all other space bodies, the Moon and Earth submits to the law of universal gravitation opened by Isaac Newton. This law says that all bodies are attracted to each other with a force directly proportional to the work of their masses and inversely proportional to a distance square between them. And if the Moon and Earth are attracted to each other, what does not allow them to face? To the moon its movement does not allow to fall to the Ground. Average distance from Earth to the Moon 384401 km. The moon moves around Earth on an elliptic orbit therefore at the maximum rapprochement the distance falls up to 356400 km, during the maximum removal it increases up to 406700 km. Speed of the movement of the Moon is 1 km a second, this speed is not enough for "escaping" from Earth, but there is enough not to fall to it. All artificial Earth satellites started by the person move around it under the same laws, as the Moon. At removal into an orbit the rocket disperses them to the first cosmic speed – it is enough to overcome gravitation of Earth and to orbit, but there is not enough completely to overcome terrestrial gravitation. Bind a heavy ball on a rope and untwist it over the head. The rope in this experience imitates gravitation, without allowing a ball Moon to depart. At the same time, the speed of rotation does not allow a ball to fall, it is in the movement all the time. And with the Moon – it will not fall until rotates around Earth, the Mass of the Moon is 81 time less than the mass of Earth. Despite this, the Moon has a huge impact on mortal life – in particular, causes the attraction inflows and otliva. Terrestrial gravitation makes even more global impact to the Moon, the strongest terrestrial gravitation led to the fact that the Moon is always turned to us by one party. In spite of the fact that the Moon is studied already by hundreds of years, it still keeps a set of secrets. Astronomers noticed a luminescence and flashes which did not find a satisfactory explanation yet on the Moon. In powerful telescopes it was possible to make out the objects moving over our natural satellite which nature is also not explained yet. These and many other riddles of the Moon still are waiting in the wings.