ANAL SPHERES rusts are several other complex systems the ally describe as spheres. These have only we ven lybeen considered as spherical layers regarded as a of the Earth's geology. As a greater understanding of their lanetary significance is gained, these external spheres are increasingly being linked to geological processes, and sometimes, being observed on other planets The hydrosphere is the liquid water on the plane luding both salt and fresh water The cryosphere is the ice water, including both mporary seasonal snow and accumulated glacier and ice-cap ice The pedosphere is the soil layers at the interface between rock and the living world The atmosphere is the gaseous layers held to the Earth by gravity, including the oxygen that we need. This can be further divided into sublayers: The lowest is the troposphere, where most life as we know it exists Above this is the stratosphere, which is often visited by aircraft Above this is the ionosphere, where the solar wind causes colourful displays known as the aurora. The outermost layer is the exosphere, where atmospheric gases are at their thinnest. ere are also special layers that are not physicall defined but represent flows of energy: The magnetosphere is the area in space that is influenced by the Earth's magnetic field. We can utilise this for navigation using compasses. It also protects us from deadly solar radiation. The biosphere is the layer of the Earth to which you, the food you eat, the forests, and all of the living things on Earth belong