The Formation History of the Moon

Several mechanisms indicate that the moon formed about 4.5 billion years ago, about 30-50 million years after solar system formed. The first theory is that Earth's moon formed from material that escapes due to centrifugal force, leaving a giant lake, which is believed to the Pacific Ocean. But this idea requires a very high rotational speed of the earth, and although this may occur, this process should produce a rotating month following the equator. This is not the case in recent months.

 

Other speculation is the moon formed somewhere in the universe simultaneously with the formation of planets, then stuck the Earth's gravity. But this condition should result in widening of the Earth's atmosphere as a result of the energy giant space for material that passes through Earth's moon.
The hypothesis goes on to say that the moon and Earth formed together the circle of the early solar system. Moon formed from material that surrounds the Earth like planets are formed from materials around the sun. But this theory can not explain the presence of iron deposits in the core of the month should be trapped in the gravitational core of the earth and formed the core of the month.

 
Throughout the above hypothesis can not explain the high angular momentum of the Earth-moon system.
The current theory is the most trusted of the collision theory. The mass of Mars hit the Earth early, releasing enough material into orbit around the earth and formed the moon through the early formation of a solid mass by gravity in the early Earth. The question that remains unanswered by this theory is how big the planet's mass and the early Earth is released into orbit and the moon form