The moon is a satellite of our planet
In 1609, after Galileo Galileo invented the telescope, mankind was able for the first time to examine in detail its space satellite. Since then, the Moon is the most studied cosmic body, as well as the first that man has been able to visit.
The first thing to figure out is what is our satellite? The answer is unexpected: although the Moon is considered a satellite, technically it is as complete a planet as the Earth. It has large dimensions - 3476 kilometers across at the equator - and a mass of 7.347 × 1022 kilograms; The moon is only slightly inferior to Mercury, the smallest planet in the Solar System. All this makes her a full-fledged participant in the Moon-Earth gravitational system.