atmosphere The gaseous mass or envelope surrounding a celestial body, especially the one surrounding Earth, and retained by the celestial bodys gravitational field.
magnetosphere An asymmetrical, bullet-shaped region around Earth, extending from about 700,000 kilometers above the surface on the day side to at least 500 million km on the night side, in which charged particles are trapped and their behavior is dominated by Earths magnetic field.
magnetic field A force field around a magnet or an electric current, characterized by the force it exerts on magnetic materials (such as a compass needle) and its ability to deflect the trajectories of charged particles.
solar wind A stream of high-speed, ionized particles ejected primarily from the suns outer atmosphere.
plasma An electrically neutral, highly ionized gas composed of ions, electrons and neutral particles. It is a phase of matter distinct from solids, liquids and normal gases.