The Moon is the only natural satellite of Earth. The distance from Earth is about 384,400km with a diameter of 3476km and a mass of 7.35*1022kg. Through history it has had many names: Called Luna by the Romans, Selene and Artemis by the Greeks. And of course, has been known through prehistoric times. It is the second brightest object in the sky after the Sun. Due to its size and composition, the Moon is sometimes …showed first 75 words of 1456 total…

…showed last 75 words of 1456 total…restricts the orbit of the impactor to lie near that of the Earth. It has also been found that collisions involving larger impactors with more than the Earth-Moon angular momentum can give "successful" outcomes. This initial condition is reasonable because it is known that the Earth-Moon system has lost angular momentum due to solar tides, but the amount is uncertain. These calculations are still in progress and will probably take 1 or 2 years more to complete