The moon has fascinated humanity for many thousands of years. It has assumed a role in legend and lore alike, being worshiped as a god, and feared as a demon. Indeed, from the days when man first looked skyward, he knew the moon served some important purpose, one he could not yet comprehend. During the scientific advances of the 1600s and the industrial and literary revolutions that soon followed, the moon played a central role in the story and equation alike. Newspapers of the 1800s proclaimed the greatest "feat of physics ever accomplished": weighing the moon. And when the man finally reached the moon in 1969, he accomplished the impossible dream of eons past. Nevertheless, with the boundary of space conquered, we have gained only a slightly greater understanding of the giant looming in the sky. Now, scientists are attempting to answer a question as complicated as space is vast: how did the moon form?
             Some important factors need to be considered in order to form a successful theory about the origin of the moon One factor is the size of the Moon relative to the Earth. The Moon is about one-fourth the size of the Earth (Editors 22).. Also, the Moon's density needs to be taken into consideration. The Moon is only 60% of the Earth's density, which indicates that the Moon is lacking in heavy metals such as iron and nickel. Also, the Moon's bulk composition appears to be similar but not identical to the Earth's upper mantle, which is comprised dominantly of iron- and magnesium-rich silicates (Spudis 137).
             A third factor that needs to be considered is the angular momentum of the Earth-Moon system. Angular momentum needs to be conserved. Therefore if the Earth slows down in its rotation then the Moon must move away from Earth a fraction to conserved momentum (Editors 23).
             There have been many theories over the years on how the moon became to be. Only four scientific theories have been accepted for any length of time. They...