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How is the moon created???

Theories of the Origin of the Moon After years of research, studying gamma rays and rock samples from the Earth and the Moon, it isgenerally accepted that the ages of the Earth and the Moon are the same. There are several theorieson its formation.

IMPACT : One theory is that it was formed from the Earth's crust, following the impact of a large(Mars-sized) asteroid. A long string of rocky fragments were blown out from the Earth in the form of atrail, which coalesced into the Moon. Supporting this, the Earth has a large iron core but the Moondoes not : the Earth's iron would have already sunken into the core by the time the giant impacthappened.

COACCRETION : Another theory, advocated by Edward Roche, is known as coaccretion. It proposesthe concurrent information of both the Earth and the Moon from clouds of space material. As a resultthe new Moon gets spun by the Earth's gravity field and starts to circle the Earth. The fact is that allsmaller solar bodies appear to be irregularly shaped, but larger ones are nearly spherical.

FISSION : The fission theory states that the Moon long ago split off from a fast-rotating Earth, likemud flung from a spinning bicycle wheel. The present Pacific Ocean basin is the most popular site forthe part of the Earth from which the Moon may have come. This is not supported by evidence of higher rotational speed in the past.

CAPTURE : If the Moon formed separately, it could have come close enough to the Earth'sgravitational field to be trapped. The angle of orbital approach would have to be within narrowparameters in relationship to the moving centre of the orbiting Earth. The chance of this occurrence isvery low without some other gravitational interaction.

The prevailing theory at present is some form of early impact, possibly by a co-orbiting object thatfused with the Earth after the collision, but that blasted loose the material which later formed theMoon.

Most widely accepted scientific explanation

It is believed that the moon formed around 4.5 billion years ago and only a few hundred million yearsafter the Earth.

Today, based on the evidence, the most widely accepted scientific explanation for the formation of theMoon is called the Giant Impact Hypothesis. According to this model, the Moon formed from debristhat was the result of a huge collision. Not long after Earth formed, a proto-planet about the size of Mars (often called Theia) smashed into it at a low angle and relatively low speed. The cataclysmicimpact rendered the entire Earth molten, and caused significant amounts of its mantle and crust to beblown into space. The metallic core of the impactor sunk through the Earth's mantle to fuse withEarth's core, thereby depleting the Moon of metallic material and explaining its unusual composition.

The force of the collision is also believed to have been responsible for tilting the Earth at angle of 23.5degrees, allowing for seasons.

The debris from the collision began orbiting the Earth and gathered together through gravity to form asphere: the Moon. The Moon formed surprisingly quickly, possibly in less than a month but no morethan a century. It started out closer to the Earth than it is today, and must have caused massivetides. Slowly, due to conservation fo angular momentum, it moved further and further out until it gotto the familiar orbit it is now. Even today, the Moon is receding from Earth by an inch and a half everyyear, but it will take billions of years for the Moon to escape from Earth's gravity altogether.

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There are still some problems with the Giant Impact hypothesis that need to be overcome. Forexample, the ratios of the Moon's volatile elements (such as water) are not explained by this model.Also, the moon's oxygen isotopic ratios are essentially identical to Earth's when they should bedifferent. Regardless, the Giant Impact model is currently the best explanation scientists have basedon the evidence that has been gathered, and holds more weight than the other theories for the Moon's

formation.