The moon

The moon is the most important desire of each amateur. The additional and superior we appreciate it, the additional we desire to identify. Its closeness make us look elder than it is, and moving quickly across the sky, where it actually runs about 12 ° per day, or about half a degree per hour (its apparent diameter).

It appears that, the unfruitful planetary shell has not changed during history known to guy because if we compare the first known maps with today, however elementary they may be does not differ in their details.

Drawing of the Moon

regardless of the higher than, we have some interesting details in his history that tell us that occasionally, something happens over there, observable to our eyes.

For example, in 1783, William Herschel, he said, that view as a blazing point in the portion that was not the moon illuminate. In 1963, from Lowell Observatory, marked another red dot near the crater Aristarchus, appear to have been caused by gas emission, according to the findings. In 1969, Apollo 11 astronauts gave a report from the same area, which seem to have lit.

In the record of the satellite, a fact also recorded in the year 1978, by a group of monks of Canterbury Cathedral. These monks saw a light, which apparently throw blaze on the curved moon. It is believed that this cast point may have been produced by the impact of a meteorite in the face of the moon, for that matter, would be hidden from view of the monks, who have only been able to see dust and molten rock were launched into space by the impact.

Impact described makes the Moon "vibrate". This could be tested by NASA, by the instruments left by the Apollo mission in 1969, Armstrong and Aldrin. Since then, the instrument left there, powered by solar energy, have involved huge number of small meteorite impacts and earthquakes. The impacts that receives, rising from the lunar surface gas clouds, which are driven by the solar wind.

The Great Plains mole, called seas and craters were discovered by Galileo, when he could watch her with his telescope in 1609. Despite the previously described, the Moon, one of the largest moons in the solar system is completely sterile, with no water or atmosphere and geologically dead. Galileo never called "seas" to the lunar plains, but plains, referring to them as well as dark spots, large or old.

Although this, the moon, which circles the Earth at an average distance of 376,600 kilometers, exerts a gravitational drag distort the planet Earth, particularly its oceans, affecting their movements, so that may help begin period glaciers. 

The opposite effect, which exerts the greatest gravitational pull of the Earth, which has slowed the rotation of the Moon, so much so that its rotation period is exactly equal to the orbital. For this, we observe that from our planet, we always see the same face.

Another result of tidal action is the long-term variation of the average distance between Earth and Moon. Earth react to brake, which the lunar tides, the moon pushing ahead (principle of action and reaction), as a result, causes a gradual widen of its orbit. Measure devices left on the moon by the Apollo missions, through mirrors located on the surface, and laser beams sent from Earth, with more than 30 years that have been making measurements, allowed us to establish that the dimension of the lunar orbit increases about 3 cm. per year.  

The birth of the Moon 

Almost all the planets of the Solar System have moons, but the Earth has a moon larger than these, only Pluto has a similar system, with its moon Char on. The size of the Earth is 3.6 times greater than that of the Moon, therefore, is that some have considered a double planet. As therefore created, nearly 4,500 million years, is a mystery, there are more than a few hypothesis.

One would be the pattern from the remains of a crash between Earth and the newest Mars-sized fragment procendente of solar system formation. In this violent encounter, the fragment impact or would have disintegrated, its metallic core would have been absorbed by the Earth and the mantle rock, escaping gravity, would have formed the Moon. This could explain the lack of iron and low density, and the inclination of 24 °, 4 axis of the Earth and also the high density of our planet.

Another theory, proposed George Darwin, son of Charles. This hypothesis says that the Earth and Moon was in principle a single star. Revolved around the sun while cooled and contracted, starting to rotate at higher speeds, when given a spin around the axis every two or three hours, the flattening of the poles and the widening of Ecuador became so great that it formed a giant material melted ball, this ball, that become trapped in Earth's orbit, it becomes our satellite: the Moon. The chemical difference in the constitution of the Earth and the Moon, could in this case, due to, as the fission theory proposed by Darwin, the Moon, it follows from the crust of the Earth, not of metal its core, hence, that the Moon is less dense than Earth.

The crash theory, suggests that even young Earth orbiting the Sun, has collided with an asteroid or comet, the material thrown by the Earth (by a deep crater), formed a ring of debris, which gradually formed the Moon.

It could also be, according to another theory, that the Moon formed elsewhere in the solar system, moving from its original orbit, was captured by the gravitational field of Earth; this version has also been applied to the moon of Neptune Triton. As it is not our subject, to discern which of these theories proposed is the right one, simple mastery, expose for the reader's information.

What we do know, is how it acquired its many craters as the moon, through more than 700 million years since its formation, has been "visited" by a multitude of meteorites that left the mark of their passage on the surface of itself. Like the moon there is no volcanic or tectonic significance, have not erased the craters left by the different impacts, which does happen on Earth.

Two Sides of the Moon

The Moon and the rest of the solar system suffered the incessant bombardment of meteorites. These pedruzcos and radioactive crumble of the internal elements caused the crust to melt. Heavy elements sank, while the feldspars, surfaced. Inside is potassium, rare earths and some phosphorus. 

The depressions that were formed by impacts, were flooded with lava, and formed large soft dark areas, which we know as "seas", some craters filled with basalt that flowed like the known crater Plato, with visible smooth and dark. 

Data from the Moon:

Distance from Earth: 384,401 km Mass: 0.012 x Earth masses Radius: 0.272 x Earth's radius Apparent size: 31 min of arc Apparent magnitude: -12 in Full Moon Rotation: 27.3 days Earth Orbit (with respect to the stars): 27.3 days Earth Orbit (as seen from Earth): 29.5 days Land Area: 37,960 km2 million or 7.4% of land area. Mean density: 3.342 g/cm3, or 61 % of the land. Escape Velocity: 2.37 km /