Called moon, all natural satellite of a planet, but the Moon, with a capital M, means the only natural satellite of Earth. The mean distance between Earth and the Moon is 384,403 km. The diameter of the Moon is 3474 km. The Hidden Side of the Moon is perpetually invisible from the Earth, it is impossible to take photographs of the face without the use of space probes. Intriguingly, the dark side is different from the face, both in terms of its average altitude and its rate of cratering.
Regularly, images and videos of the spectacular lunar surface and especially its dark side, we are sent by U.S. and Japanese probes.
U.S. Clementine mission had not seen the full moon but the probe Selene-Kaguya, the largest lunar mission since the Apollo program, launched in 2007, sent us photographs of a high accuracy of the order of 10 meters per pixel. This enabled the detection of new craters and thus to refine the measure of the rate of lunar cratering land. The dark side of the moon, we reached the large crater images Leibnitz (245 km diameter) crater Finsen (72 km diameter) crater Davisson (87 km diameter),... Credit: JAXA, NHK
The origin of the Moon is the subject of scientific debate. The analysis of lunar rocks highlights an interesting theory about the origin of the Moon.
These materials come from the mantle of two large planetary objects.
Shock of a huge shake the very young Earth in formation.
The companion of our nights might be a result of accretion of material ejected during the great crash. At the beginning of the creation of the Earth, a very large planetesimal the size of Mars, also a differential (metallic core, mantle,...) that a particular angle of impact and a relatively high speed, collided the Earth.
This collision caused the merger of the two metal cores, while the mantle materials of the two objects were thrown, but related to the Earth by gravity.
Most of its materials will slowly coalesce around what will become our Moon. All this happens very early in the history of the Earth, who does not keep track. Nevertheless, numerical simulations are able to represent fairly well in stages (see drawing opposite).
On the other hand, this assumption is not contradictory with what is currently known about the Moon and supports this idea.
The asteroid that hit the Moon at this point would be about 10 km in diameter. The shock caused a perfectly circular excavation to a depth of 4700 meters. The center of the crater is occupied by small mountains, the central peak, is over 2000 meters. The central peak was raised as a result of the sudden compression of the collision with the asteroid. It measures ten miles at its base. June 10, 2011, LRO has captured the rays of sun caressing the central peak of Tycho.