How The Moon Was Formed

One of the more popular theories on the formation of moon goes something like this: During the formation of earth, a huge object (a comet or another planet?) hit earth with a giant impact. This caused a huge amount of debris to scatter into the atmosphere. With gravity and other elements at work, it formed somewhat of a ring of debris around earth. After billions of years, this debris coalesced into the moon. This theory is called the Giant Impact Hypothesis. It works on several levels as much of the composition of the moon, is the same as earth. Does this type of impact and creation of satellites happen often? Less than 20% of the time according to studies of other planets moons in our solar system. This a great story to tell your friends when you gaze up at the sky!