Isn't This All Bunkum?
Are we really suggesting that someone or something came along 4.6 billion years ago and 'manufactured' the Moon from surface material taken from the Earth? We are, and when 'all' the evidence is taken into account this is the most reasonable explanation. It may sound odd, it might even appear mad, but using Occum's razor it is the most likely scenario.
Why Are We So Sure?
It's all to do with the difference between things that come about as a result of chance and those that are deliberately and knowingly created. A good example might be the thousands of 'hand axes' found by archaeologists all over the world. Hand axes were used by our ancient ancestors for a variety of jobs and were often made out of flint or obsidian.
To the untrained eye a hand axe, especially a very early example, might just look like a random piece of rock, but when inspected closely it can be seen to have a shape and a structure that could not come about by chance. Hand axes were carefully chipped into shape and were often polished and given a very sharp edge. So whilst perfectly ordinary pieces of rock were used to make hand axes, the finished axe is not a creation of nature but of the thought and dexterity of human beings.
Something More Complex
If we look at something far more complex, like a car for example, anyone could see just from its shape and complexity that it is not a naturally occurring object. Nature could never produce a car, even though it is created entirely within the laws of physics. If we took the car to pieces and measured all its componants very carefully, we would even be able to work out what measuring system was used by its manufacturers. The very 'regularity' of the components of the car would tell us that it was engineered by man and was not a spontaneous creation of nature.
Message in a Bottle
Despite the fact that someone or something created the Moon, no law of physics had to be in any way altered to do so. The same is true of the car, or any other manmade object. The fact that we, as a species, can manufacture things is a testament to our ingenuity in using natural materials (or even artificial ones these days) and working within the laws of physics to create something that we want or need.
But just supposing we thought there might be some confusion and we wanted someone in the future to recognise our work as being manufactured rather than natural? As an example we might create a sculpture, using perfectly normal and natural materials such as stone or metal. How could we let people far into the future know that we had used our creativity to turn something natural into something artificial? One way we might do it is to introduce mathematics into our creation of a sort that could never come about by chance.
If our sculpture was angular in shape, with sides of a defined length, we might make all the sides the same size or ratios of all the others. This is not something that would happen in the natural world and would betray the artificial nature of the object. We might incorporate concepts such as Pi into our sculpture, or make the ratios of its various sides create mathematical equations or define mathematical laws that again would never come about by chance. Including such messages deliberately (or perhaps even accidentally) would ensure that there could be no mistake as to the origin of the sculpture. These are 'messages in a bottle'. However, they are not written messags but rather those of math, to which all human cultures come eventually. Writing can be misunderstood or remain totally undeciphered but math is universal.
Messages in the Moon
The Moon is a sculpture of sorts, but it is also a very powerful machine. It doesn't need an engine or any sort using artifical motive power because it was manufactured in such a way that it would be powered by natural physics, using gravity specifically. It betrays its artificial origins in many different ways and most of the messages were included 'deliberately' because the builders of the Moon 'wanted' us to take notice.
First Message - Eclipses
Solar eclipses happen when the shadow of the Moon covers the surface of the Sun. Total solar eclipses are very impressive and for one important reason: when seen from the Earth the disc of the Moon is exactly the same size as that of the Sun. This isn't the case but is a line-of-site effect. In reality the Sun is much more massive than the Moon but is very much further away. Solar eclipses are a near miracle and they don't happen anywhere else in the solar system. The only reason they can occur is because of two factors. The Moon is 1/400th part the size of the Sun, and the Moon is capable of standing at a position 1/400th part of the distance between the Earth and the Sun. How unlikely is that? If any message incorporated into the Moon was specifically designed to say "Look at me more closely" it is solar ecilipses.
Second Message - the Scissoring of the Moon
It is a peculiar fact that when viewed from the Earth, the Moon and the Sun perform an elegant and most unlikely dance. At times when the Sun rises at dawn as far north as it can, the Moon sets as far south as is possible. Similarly, when the Sun rises at its extreme southern position, the Moon sets at its most northerly. The same is true of Sunset and Moonrise. Hardly anyone even realises that this takes place, let alone understands just how incredible it is. There is no mathematical rule or law of physics that says this should happen. It is simply a consequence of the Moon's orbit and positioning and yet as a random chance event it seems virtually miraculous.