The Earth is unique in having a satellite as large as the Moon so close to it. This does mean that the Moon has a number of influences on the Earth. It’s more obvious influence is on the Earth’s oceanic tides. With some areas being affected more than others.
If you look at the tide level between the U.K. and mainland Europe, there is a tidal increase of up to 10 metres. Travelling to the pacific areas shows a tidal increase of about 1 meter. This influence extends to the oceanic streams and currents, without which our climate would be severely affected.
The Moon also has an affect on the crust of the Earth, causing a rolling convective movement, that is not seen on other planets in the solar system. It is believed that it is this movement that causes heating and dissipation of energy through the tectonic plates.
Although it isn’t noticeable to us, the oceans bulge at the equator because of the gravitational pulling effect of the Moon. If we suddenly lost the moon, this bulge of water would be dissipated, causing the sea level to rise around the Earth.
There is also the stabilisation effect the Moon has on the Earth’s axis of rotation. Without this influence the Earth would wobble more on its axis, and our climate would go through quite radical seasonal changes. Fortunately for us, Moon has also been the Earth’s ‘punch bag’, taking the big hits from passing comets, and acting as a protective shield.
It is not only geological influences that the Moon is responsible for, but biological as well. Animals, fish, and plant life have all adapted to a life that is dependant on the tides. Without them, most would not be able to survive.
There is another influence that the Moon has on the Earth, and that is our enrichment through art and science. It can be argued that the development of mathematics has also been encouraged by the Moon. After all, the observation of the Moon’s phases, and the calculation of their time spans have encouraged humans to find out more about the universe around them.
The stories and legends spawned by the mystery and curiosity surrounding the Moon has greatly enriched our civilisations. Our sciences and technologies have also been influenced and encouraged by our need to explore our satellite. The Moon may have been a random and purely chance occurrence in space, but it is now a most influential and essential part of our existence.