The Composition of the Earth

The composition of the Earth, it's distance from the sun, it's speed of revolution are all significant factors in making it a perfect place for the development of life. The graphic shows the composition of Earth as having 34.6 % of Iron, 2.4 % nickel and 29.5% oxygen. It is not only the composition that is significant it is how these and the other elements are distributed on or in the Earth.

The core of the Earth is believed to be mostly composed of iron and nickel in a molten mixture and that this material is the cause of Earth's magnet fields. We have known for many years that the magnetic field of the Earth does reverse ar regular intervals and has reversed in the past and will again reverse at some point in the future. The heat inside the Earth may be the result of great pressure and friction of the matter and nuclear decay of radioactive materials.

Oxygen can be found as a component of air in the form of molecules of O2, but can also be found as molecules of O3 (Ozone). It is thought that the ozone may be formed mostly from lightning and that ozone tends to move toward the upper atmosphere where it forms a protective layer that shields the Earth from ultraviolet radiation.

A great deal of Oxygen is also bound into other molecules with water being one of the most important. If water had not been formed in vast quantities on the surface of the Earth, the great diversity of life would most likely have been limited. Even with a small amount of water life might have developed. This water had to have been developed in the Earth's history because hydrogen that was not bonded would have drifted toward the very uppermost parts of the atmosphere and then moved into space.

Our bodies do not have the same composition as the Earth. Our bodies are composed of up to 65% of oxygen and different proportions of other elements also, but the iron in our blood is the vital element that makes our blood red when exposed to oxygen. In a way our blood "rusts" in the presence of oxygen. It is very important that our blood can bond with oxygen and then later release it to other tissues of the body.

The composition of other planets in the universe will be different, but there must be a large number with a similar composition to that of the Earth, that must be the right distance from a sun, that must have the correct revolution speed to provide a similar environment suitable for life as we know it. This does not mean that life can not exist on planets with completely different compositions and with completely different forms of life.