EarthRef.org Digital Archive (ERDA) -- Earth's Magnetic Field

Description
The image shows how the Earth's magnetic field appears in space due to interactions with solar wind from the sun and provides an introduction into the pieces that make up the magnetic field. First, the magnetic field is generated from convection (circulation) of the Earth's liquid outer core, which is composed primarily of iron (known as the Dynamo Theory). The magnetic field occurs all around the Earth and the area contained within is referred to as the Magnetosphere, also known as the region of space influenced by the Earth's magnetic field. The Magnetopause is the layer at the boundary of the magnetiosphere. The Plasma Sheet is a layer of thick plasma that separates the magnetotail (the right side of the magnetic field in the picture) into two parts, each having an opposite magnetic field direction than the other. This is important because it keeps the two sides from interacting, which would cause the magnetic field to cancel itself out. Plasma is formed when a gas is under extremely high temperatures, giving electrons enough energy to escape from their respective nucleus. A plasma environment is composed of positively charged ions and negatively charged electrons. The Sun's magnetic field is also known as the Interplanetary Magnetic Field, which affects all of the planets in the solar system and is carried by solar wind. Solar Wind is matter released by the sun and travels into space, eventually running into the Earth's magnetic field. It is made up of mostly hydrogen that is also in a plasma phase. The magnetic field is the Earth's primary defense against solar wind and is able to deflect most of it away, protecting the planet.