The Moon Earth's natural satellite
The moon, natural satellite of the Earth and its nearest neighbor in heaven, is an object of enduring fascination for the observation with instruments of all sizes.
Despite its small size (3476 km in diameter, about one quarter of the Earth) it is so close, on average 384,400 kilometers, that even with an ordinary pair of binoculars reveals a wealth of detail of its surface full of craters.
Each month the Moon goes through a cycle of phases from new moon (not illuminated by the Sun) to the crescent moon (first quarter), the full moon, the waning moon (last quarter), to return to new moon.
Strictly speaking there are two types of month: one lasts 27.3 days, the time it takes the Moon to make one revolution around the Earth and is called the sidereal month, but the Earth during this time, it also moves relative to the Sun , so that the Moon has to do something more than a revolution to return to the same position as observed from Earth, and the time it takes to do what is called the synodic month.
Each point on the lunar surface is illuminated by the Sun for two weeks during which the surface temperature reaches the boiling point of water (about 100 ° C) followed by a night for two weeks when the temperature falls to -170 ° C.
The dark plains are called "seas" because early observers thought that there was water in those places: the current nomenclature moon we owe it to an Italian astronomer, Giovanni Riccioli this, which in 1651 published a paper containing many of the names lunar hours universally accepted, assegnandosi a substantial crater near the edge of the moon, next to a large formation that bears the name of his pupil Francesco Grimaldi.
From time immemorial the Moon is recognized as the symbol of the Mother Goddess, which illuminates the night sky of stars and protects her children during sleep, but also leads them to discover the dark side (but not evil) of his own psyche, which is connected in an indissoluble bond, just look at how the phase of full moon triggers in the minds of men more sensitive, often unorthodox acts of unrestrained violence or other charges, perhaps even for the "castratura" that the Church has made in recent 1000 years.
In many cultures is attributed to a dangerous destructive side of our star the night, perhaps because to refer to myths and legends that they see it as a satellite came from the depths of the cosmos, bringer of destruction resulted from its magnetic force, until he testified at the right distance, so that it begins to affect the tides with its proximity or distance.
Some researchers argue that it is a piece of land broke away from it after a huge meteorite hit the millions or perhaps billions of years ago, during its formation, others allege that it was captured by the magnetic force of the Sun, first, and then by Earth, then, remains imprisoned.
Another theory says it could be a huge spaceship or semi artificial planetoid, built by some alien race, who parked in orbit with the planet and settled here, where he began the history of the Earth, hence the legends and myths of Atlantis mu, and so on.