HHmmmm....
http://home.case.edu/~sjr16/earth_moon.html
The moon is Earth's closest celestial neighbor. It has a huge influence upon our lives, governs the tides (the sun plays a small part, but not nearly as much as the Moon), and is responsible for eclipses. Some biologists say that the moon is even responsible - in part - for life on Earth, for without the tides causing currents and mixing of chemicals, life might never have formed.
The moon lies, on average, 384,400 km (238,900 miles) away and takes 27.3 days to orbit the Earth. Strange as it may seem, its rotation period is exactly the same as its orbital period, something that scientists call tidally locked. Therefore, one half is always facing the Earth while the other half is always facing away. This means that there isn't really a "Dark Side" of the moon. Also, contrary to popular opinion, there have been people on the far side, and it has been extensively photographed and mapped.
Surface and Atmosphere
The moon has a very heavily cratered surface, which tells the tale of solar system. Earth would be the same way if it had no atmosphere nor plate tectonics. Without an atmosphere or water to erode the craters, the lunar landscape has remained relatively constant for billions of years.
It is through these craters that we can actually tell some of the solar system's history. Through dating the craters, planetary scientists have been able to determine that most of the craters were made in the early days of the solar system, approximately 3.8-4.5 billion years ago. This means that early in the solar system, there was a period of heavy asteroid bombardment. This is most likely due to all of the extra material left over from the solar system's formation. After approximately 1.2 billion years, most of the material had formed into the Asteroid Belt, been ejected from the solar system, or hit the planets and moons.
If you look at the moon closely, you can see dark patches. After the period of heavy asteroid bombardment, the moon's surface cracked in many places. The lowlands of the moon filled with volcanic material, which then cooled. This lasted for approximately 750 million years. They are called maria (singular is mare) due to their resemblance to dark oceans.
The moon has remained relatively static (unchanging) for the last 2.5 billion years, with the occasional asteroid impact.
Creation
There are four main theories about the creation of the moon, although only one is generally considered to give an accurate description of what actually occurred.
The first theory states that the moon was created the same way the planets were - through the coalescing of gas and dust during the solar system's formation. The second theory says that the moon is a captured asteroid. The third theory says that when the Earth was first formed it was spinning so rapidly that it split in two; this is often referred to the "fission" theory*.
The fourth theory is the one that most scientists currently believe is correct. It states that when the Earth was quite young, a Mars -sized planet crashed into it. The planet crashed with such speed that it was completely destroyed, and almost destroyed the Earth. The planet was coming in with such force that when it was destroyed, the molten iron in its core continued to travel through Earth, to eventually be included it its core. This explains why the Moon has very little iron. The crash, comically dubbed the "Big Splash," sent tons of rock and debris into orbit. These fragments eventually coalesced to form the Moon. The tidal and rotational forces in play also account for why the moon's day is exactly the same as it's "year."
Peace